CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Patent Application No. 62/413,286, filed on October 26, 2016, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] This disclosure generally relates to systems, methods, and devices for wireless communications and, more particularly, systems, methods, and devices for channel estimation for wireless networks.

BACKGROUND

[0003] Various standards, for example, Institute of Electrical and Electronics Engineers (IEEE) 802. 1 1 ay, are being developed for the millimeter (mm) wave (for example, 60 GHz) frequency band of the spectrum. For example, IEEE 802. 1 1 ay is one such standard. IEEE 802. H ay is related to the IEEE 802. H ad standard, also known as WiGig. IEEE 802. H ay seeks, in part, to increase the transmission data rate between two or more devices in a network, for example, by implementing Multiple Input Multiple Output (MIMO) techniques.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 shows an exemplary network environment in accordance with one or more example embodiments of the disclosure.

[0005] FIG. 2 shows a diagram of an example enhanced directional multi-gigabit (EDMG) Channel Estimation Field (CEF) for Single Carrier (SC) multiple-input and multiple-output (MIMO) design, in accordance with one or more example embodiments of the disclosure.

[0006] FIG. 3 shows an example channel estimation (CE) subfield, in accordance with example embodiments of the disclosure.

[0007] FIG. 4 shows another example extended EDMG CEF design for SC MIMO, in accordance with example embodiments of the disclosure. [0008] FIGs. 5A, 5B, 5C, 5D, 5E, 5F, 5G, 5H, 51, 5J, 5K, 5L, 5M, 5N, 50, and 5P show example CE subfields, in accordance with example embodiments of the disclosure.

[0009] FIG. 6 shows an example correlator output for CE subfield for N=128, in accordance with example embodiments of the disclosure.

[0010] FIG. 7 illustrates another example correlator output for CE subfield for N=128, in accordance with one or more example embodiments of the present disclosure.

[001 1] FIG. 8 shows a diagram of an example flow chart of example operations of the disclosed systems, methods, and apparatus, in accordance with one or more example embodiments of the disclosure.

[0012] FIG. 9 shows a diagram of another example flow chart of example operations of the disclosed systems, methods, and apparatus, in accordance with one or more example embodiments of the disclosure.

[0013] FIG. 10 illustrates a functional diagram of an example communication station that may be suitable for use as a user device, in accordance with one or more example embodiments of the disclosure.

[0014] FIG. 1 1 shows a block diagram of an example machine upon which any of one or more techniques (e.g., methods) may be performed, in accordance with one or more embodiments of the disclosure.

DETAILED DESCRIPTION

[0015] Example embodiments described herein provide certain systems, methods, and devices, for providing signaling information to Wi-Fi devices in various Wi-Fi networks, including, but not limited to, WiGig.

[0016] The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

[0017] Discussions herein utilizing terms such as, for example, "processing", "computing", "calculating", "determining", "establishing", "analyzing", "checking", or the like, may refer to operation(s) and/or process(es) of a computer, a computing platform, a computing system, or other electronic computing device, that manipulate and/or transform data represented as physical (e.g., electronic) quantities within the computer's registers and/or memories into other data similarly represented as physical quantities within the computer's registers and/or memories or other information storage medium that may store instructions to perform operations and/or processes. The terms "plurality" and "a plurality", as used herein, include, for example, "multiple" or "two or more". For example, "a plurality of items" includes two or more items.

[0018] References to "one embodiment", "an embodiment", "demonstrative embodiment", "various embodiments" etc., indicate that the embodiment(s) so described may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes the particular feature, structure, or characteristic. Further, repeated use of the phrase "in one embodiment" does not necessarily refer to the same embodiment, although it may.

[0019] As used herein, unless otherwise specified the use of the ordinal adjectives "first", "second", "third" etc., to describe a common object, merely indicate that different instances of like objects are being referred to, and are not intended to imply that the objects so described must be in a given sequence, either temporally, spatially, in ranking, or in any other manner.

[0020] Various standards, for example, Institute of Electrical and Electronics Engineers (IEEE) 802.1 1 ay, are being developed for the millimeter (mm) wave (for example, 60 GHz) frequency band of the spectrum. For example, IEEE 802. 1 1 ay is one such standard. IEEE 802. H ay is related to the IEEE 802. H ad standard, also known as WiGig. IEEE 802. H ay seeks, in part, to increase the transmission data rate between two or more devices in a network, for example, by implementing Multiple Input Multiple Output (MIMO) techniques.

[0021] In wireless networks, signals can be sent and received between transmitters and receivers through one or more channels. Such channels can induce distortions in the signal transmitted and received. To handle the distortions and maintain signal integrity, the characteristics of the one or more channels, at a given time, can be determined to estimate the induced distortion to the signals transmitted and received by the channels, that is, performing channel estimation.

[0022] One technique for performing channel estimation in wireless systems includes transmitting, by a transmitter, signals with predetermined sequences and comparing the signals received in a receiver. For example, auto-correlation and/or cross-correlation can be performed on the received signals with predetermined sequences to estimate the channel characteristics. Since the sequences of the transmitted signals are known to the receiver, the results of the correlation operation can yield the estimation of the channel characteristics, for example, the impulse response of the channel.

[0023] For efficient channel estimation, sequences with predetermined autocorrelation properties, such as complementary sequences (for example, Golay complementary sequences), can be transmitted by the transmitter and auto-correlated by the receiver, for example, in one or more channel estimation fields (CEF) of data packets that contain the transmitted signal. In one embodiment, Golay complementary sequences can refer to sequences of bipolar symbols (±1) that can be mathematically constructed to have specific autocorrelation properties. In particular, one property of Golay complementary sequences is that they can have a sum of autocorrelations that equals a delta function, which can be defined, in part as a function on the real number line that is zero everywhere except at zero, with an integral of one over the entire real line.

[0024] In one embodiment, channel state information (CSI) can refer to known channel properties of a communication link. This information can describe how a signal propagates from the transmitter to the receiver and represents the combined effect of, for example, scattering, fading, and power decay with distance. The CSI can make it possible to adapt transmissions to current channel conditions, which can be important for achieving reliable communication with high data rates in multi-antenna systems. In various embodiments, this disclosure describes Golay sequences and Golay Sequence Sets (GSSs) for channel estimation and extracting of CSI.

[0025] In various embodiments, the disclosed GSSs can include a number of Golay complementary pairs (for example, Ga and Gb). In one embodiment, the disclosed Golay complementary pairs can meet various predetermined rules and can be used to define enhanced directional multi-gigabit (EDMG) short training field (STF) and CEF fields for multiple-input and multiple-output (MIMO) transmission. In one embodiment, multiple- input and multiple-output (MIMO) can refer to a method for multiplying the capacity of a radio link using multiple transmit and receive antennas to exploit multipath propagation. In one embodiment, MIMO can include various subtypes, including, for example: multiple-input and single-output (MISO), which can refer to a case when the receiver has a single antenna; single-input and multiple-output (SIMO), which can refer to a case when the transmitter has a single antenna; and single-input single-output (SISO) which can refer to a conventional radio system where neither transmitter nor receiver has multiple antennas. In one embodiment, the disclosure can be used in connection with, but is not limited to, all of the above mentioned forms of MIMO.

[0026] In various embodiments, a GSS generation system may produce complementary sequences of an arbitrary length. In one embodiment, a GSS for a sequence can be defined in terms of delay vector and/or a weight vector. Further, in another embodiment, the delay vector and/or a weight vector can be described in accordance with one or more standards, for example, in accordance with IEEE 802.11 ad standards. The Ga and Gb sequences can be generated using these vectors, for example, by using Golay generator structures. Furthermore, the delay vector and the weight vector can be based at least in part on the (Ga, Gb) complementary pair.

[0027] Example embodiments of the present disclosure can include a Golay generator that can generate Golay complementary sequences (Ga, Gb) which can be modulated and transmitted, for example, using a modulator. The modulator may be, for example, an Orthogonal Frequency Division Multiplexing (OFDM) modulator, a single carrier (SC) modulator, and the like. In one embodiment, a Golay generator can generate the complementary sequences.

[0028] The signals including the Golay sequences can be received at a receiving device. Because of the channel conditions, the received Golay sequences Ga', Gb' may be different from the original Golay sequences Ga, Gb. However, a Golay correlator can correlate the received sequences. The received signal S' (including sequences Ga',Gb') can be filtered using a filter. Then, the cross-correlation results can indicate the channel estimation as provided by the Golay correlator. Further, in various embodiments, an equalizer can equalize the received signals S' based on the output of the Golay correlator. The equalized signals can be de-modulated using a demodulator to obtain an estimate of the originally transmitted signal.

[0029] In one embodiment, a wireless network used in connection with the systems and methods of this disclosure may also include one or more legacy devices. Legacy devices can include those devices compliant with an earlier version of a given standard, but can reside in the same network as devices compliant with a later version of the standard. In one embodiment, disclosed herein are systems, methods, and devices that can permit legacy devices to communicate with and perform channel estimation with newer version devices. Thus, newer devices or components using current standards can have backward compatibility with legacy devices within a network. These devices and components can be adaptable to legacy standards and current standards when transmitting information within the network. For example, backward compatibility with legacy devices may be enabled at either a physical (PHY) layer or a Media-Specific Access Control (MAC) layer. At the PHY layer, backward compatibility can be achieved, for example, by re-using the PHY preamble from a previous standard. Legacy devices may decode the preamble portion of the signals, which may provide sufficient information for determining the channel estimation or other relevant information for the transmission and reception of the signals. At the MAC layer, backward compatibility with legacy devices may be enabled by having devices that are compliant with a newer version of the standard transmit additional frames using modes or data rates that are employed by legacy devices.

[0030] Various legacy standards can use Golay complementary sequences (which can be denoted as Ga and Gb) to define short training fields (STFs) and channel estimation fields (CEFs) associated with a preamble of a data packet. For example, the STF field can have multiple uses in wireless networks, including, but not limited to, packet detection, carrier frequency offset estimation, noise power estimation, synchronization, automatic gain control (AGC) setup and other possible signal estimations. As another example, the CEF can be used for the channel estimation in the time or the frequency domain. In the time domain, a Golay correlator can be used to perform matched filter operations without requiring the implementation of multipliers.

[0031] In various embodiments, this disclosure describes Golay sequences and Golay Sequence Sets (GSSs) for use in connection with channel estimation in wireless networks. In one embodiment, this disclosure describes an extension of the Golay sequences Ga and Gb defined in various legacy standards to GSSs. In various embodiments, the disclosure describes an extension of Enhanced Directional Multi Gigabit (EDMG) Channel Estimation Field (CEF) design for Single Carrier (SC) multiple-input and multiple-output (MIMO). The disclosure can permit more accurate channel estimation for wireless communication in a time domain and/or a frequency domain. [0032] In various embodiments, the disclosed GSSs can include a number of Golay complementary pairs (for example, Ga and Gb) which can alternatively or additionally, be referred to and/or Golay complementary sequences. In one embodiment, the disclosed Golay complementary pairs can meet various predetermined rules and can be used to define enhanced EDMG STF and CEF fields for multiple-input and multiple-output (MIMO) transmission.

[0033] In one embodiment, the EDMG CEF can use Golay complementary sequences, denoted herein alternatively or additionally as Ga and Gb. In one embodiment, the Golay complementary sequences can be described to be at least in partial conformance with one or more standards, for example, the Institute of Electrical and Electronics Engineers (IEEE) 802.11 ad standard. In another embodiment, the Golay complementary sequences can permit channel estimation in the time domain and/or the frequency domain with zero or near-zero interstream interference (ISI). In one embodiment, ISI can refer to a form of distortion of a signal in which one symbol interferes with subsequent symbols. In one embodiment, ISI can be caused by multipath propagation or the inherent non-linear frequency response of a channel causing successive symbols to "blur" together. In one embodiment by mitigating the effects of ISI, data can be transmitted by a transmitting device to a receiving device over a network with a reduced error rate.

[0034] In one embodiment, the Golay complementary sequences disclosed herein can include an extendable structure, for example, for use in connection with an arbitrary M x N multiple-input and multiple-output (MIMO) configuration, where M and N are positive integers that can represent the number of antennas used at the transmitting device and receiving device, respectively. In another embodiment, the Golay complementary sequences can be used to define EDMG CEFs for a predetermined channel bonding (CB) factor (for example, for CB factors CB = 1 , 2, 3 and 4), using an appropriate choice of Golay sequence length N. In one embodiment, channel bonding can refer to a networking arrangement in two or more channels are combined for redundancy or increased throughput. For example, neighboring 20 MHz channels can be bonded together to form a larger channel. By doubling the channel width, the data capacity of the transmission can be approximately doubled.

[0035] FIG. 1 is a diagram illustrating an example network environment, according to some example embodiments of the present disclosure. Wireless network 100 may include one or more devices 120 and one or more access point(s) (AP) 102, which may communicate in accordance with IEEE 802.11 communication standards, including IEEE 802. Had and/or IEEE 802. H ay. The device(s) 120 may be mobile devices that are non-stationary and do not have fixed locations.

[0036] The user device(s) 120 (e.g., 124, 126, or 128) may include any suitable processor-driven user device including, but not limited to, a desktop user device, a laptop user device, a server, a router, a switch, an access point, a smartphone, a tablet, wearable wireless device (e.g., bracelet, watch, glasses, ring, etc.) and so forth. In some embodiments, the user devices 120 and AP 102 may include one or more computer systems similar to that of the functional diagram of FIG. 10 and/or the example machine/system of FIG. 1 1 to be discussed further.

[0037] Returning to FIG. 1 , any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to communicate with each other via one or more communications networks 130 and/or 135, wirelessly or wired. Any of the communications networks 130 and/or 135 may include, but not limited to, any one of a combination of different types of suitable communications networks such as, for example, broadcasting networks, cable networks, public networks (e.g., the Internet), private networks, wireless networks, cellular networks, or any other suitable private and/or public networks. Further, any of the communications networks 130 and/or 135 may have any suitable communication range associated therewith and may include, for example, global networks (e.g., the Internet), metropolitan area networks (MANs), wide area networks (WANs), local area networks (LANs), or personal area networks (PANs). In addition, any of the communications networks 130 and/or 135 may include any type of medium over which network traffic may be carried including, but not limited to, coaxial cable, twisted-pair wire, optical fiber, a hybrid fiber coaxial (HFC) medium, microwave terrestrial transceivers, radio frequency communication mediums, white space communication mediums, ultra-high frequency communication mediums, satellite communication mediums, or any combination thereof.

[0038] Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may include one or more communications antennas. The one or more communications antennas may be any suitable type of antennas corresponding to the communications protocols used by the user device(s) 120 (e.g., user devices 124, 126 and 128), and AP 102. Some non-limiting examples of suitable communications antennas include Wi-Fi antennas, Institute of Electrical and Electronics Engineers (IEEE) 802.1 1 family of standards compatible antennas, directional antennas, non-directional antennas, dipole antennas, folded dipole antennas, patch antennas, multiple-input multiple-output (MIMO) antennas, omnidirectional antennas, quasi- omnidirectional antennas, or the like. The one or more communications antennas may be communicatively coupled to a radio component to transmit and/or receive signals, such as communications signals to and/or from the user device(s) 120 (e.g., user devices 124, 126, 128), and/or AP 102.

[0039] Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to perform directional transmission and/or directional reception in conjunction with wirelessly communicating in a wireless network. Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to perform such directional transmission and/or reception using a set of multiple antenna arrays (e.g., DMG antenna arrays or the like). Each of the multiple antenna arrays may be used for transmission and/or reception in a particular respective direction or range of directions. Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to perform any given directional transmission towards one or more defined transmit sectors. Any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 may be configured to perform any given directional reception from one or more defined receive sectors.

[0040] MIMO bearnforming in a wireless network may be accomplished using RF beamforming and/or digital bearnforming. In some embodiments, in performing a given MIMO transmission, user devices 120 (e.g., user devices 124, 126, 128), and/or AP 102 may be configured to use all or a subset of its one or more communications antennas to perform MIMO beamforming.

[0041] Any of the user devices 120 (e.g., user devices 124, 126, 128), and AP 102 may include any suitable radio and/or transceiver for transmitting and/or receiving radio frequency (RF) signals in the bandwidth and/or channels corresponding to the communications protocols utilized by any of the user device(s) 120 (e.g., user devices 124, 126, 128), and AP 102 to communicate with each other. The radio components may include hardware and/or software to modulate and/or demodulate communications signals according to pre-established transmission protocols. The radio components may further have hardware and/or software instructions to communicate via one or more Wi-Fi and/or Wi-Fi direct protocols, as standardized by the Institute of Electrical and Electronics Engineers (IEEE) 802.1 1 standards. In certain example embodiments, the radio component, in cooperation with the communications antennas, may be configured to communicate via 2.4 GHz channels (e.g. 802.11b, 802.1 lg, 802.11 ^η , 802.1 lax), 5 GHz channels (e.g. 802.11 ^η , 802.1 lac, 802.1 lax), or 60 GHZ channels (e.g. 802.11 ad and/or 802.11 ay). In some embodiments, non-Wi-Fi protocols may be used for communications between devices, such as Bluetooth, dedicated short-range communication (DSRC), Ultra-High Frequency (UHF) (e.g., IEEE 802.11af, IEEE 802.22), white band frequency (e.g., white spaces), or other packetized radio communications. The radio component may include any known receiver and baseband suitable for communicating via the communications protocols. The radio component may further include a low noise amplifier (LNA), additional signal amplifiers, an analog-to-digital (A/D) converter, one or more buffers, and digital baseband.

[0042] Typically, when an AP (e.g., AP 102) establishes communication with one or more user devices 120 (e.g., user devices 124, 126, and/or 128), the AP may communicate in the downlink direction by sending data frames (e.g., 142); the frames may include one or more channel estimation (CE) fields and/or short training fields (STFs). In one embodiment, the CE fields and/or the STF fields can include one or more Golay sequences that can be used for performing channel estimation. The data frames may be preceded by one or more preambles that may be part of one or more headers. These preambles may be used to allow the user device to detect a new incoming data frame from the AP. A preamble may be a signal used in network communications to synchronize transmission timing between two or more devices (e.g., between the APs and user devices).

[0043] Channel state information (CSI) can refer to known channel properties of a communication link. This information describes how a signal propagates from the transmitter to the receiver and represents the combined effect of, for example, scattering, fading, and power decay with distance. The CSI can make it possible to adapt transmissions to current channel conditions, which can be important for achieving reliable communication with high data rates in multi-antenna systems. In various embodiments, this disclosure describes CE fields that can include Golay sequences and Golay Sequence Sets (GSSs) to be used for channel estimation and determining of CSI.

[0044] FIG. 2 shows a diagram 200 of an example EDMG CEF design that can permit channel estimation for Single Carrier (SC) MIMO using 8 spatial streams in accordance with example embodiments of the disclosure. In one embodiment, the duration of the EDMG CEF field can depend on the actual number of spatial streams (NSS). In an embodiment, for 2 streams the EDMG CEF duration can be equal to time interval T = Tl, as shown by group 202.

[0045] In another embodiment, for NSS = 3 or 4, the EDMG CEF duration can be equal to 2 time intervals, that is, T = Tl + T2, as shown by groups 204 and 206. In one embodiment, for NSS = 5 through NSS = 8, the EDMG CEF duration can be equal to 4 time intervals, that is, T = Tl + T2 + T3 + T4, as shown by groups 208 and 210.

[0046] In a further embodiment, the EDMG CEF field can include a number of channel estimation (denoted CEi, where i represents an integer) subfields. In one embodiment, the channel estimation subfields can also depend on the number of spatial streams (NSS). In an embodiment, for 2 streams the channel estimation can be performed by using CEI and CE2, as shown by group 202.

[0047] In another embodiment, for NSS = 3 streams the channel estimation can be performed by using CEI, CE2, CE3, and -CE3, as shown by group 204. In one embodiment, for NSS = 4 streams the channel estimation can be performed by using CEI, CE2, CE3,- CE3, CE4, and -CE4 as shown by group 206. In one embodiment, for NSS = 5 streams the channel estimation can be performed by using CEI, CE2, CE3,-CE3, CE4,-CE4, CE5, and - CE5 as shown by group 208. In one embodiment, for NSS = 5 streams the channel estimation can be performed by using CEI, CE2, CE3,-CE3, CE4,-CE4, CE5, and -CE5 as shown by group 208.

[0048] In one embodiment, for NSS = 5 through 8 streams the channel estimation can be performed by using CEI, CE2, CE3 -CE3, CE4 -CE4, CE5 -CE5, CE6, -CE6, CE7, -CE7, CE8, and -CE8 as shown by group 210.

[0049] In one embodiment, the CE subfields may have different signs. In particular, in one embodiment, the signs of the CEi subfields can be selected in accordance with signs of an orthogonal matrix, which can be referred to herein as a P matrix:

[0050] P =

[0051] In one embodiment, the P matrix can be a Hadamard orthogonal matrix composed of ±1 elements. A given row of the P matrix can correspond to the pair of streams, that is, streams 1 and 2, streams 3 and 4, streams 5 and 6, and streams 7 and 8 as shown in FIG. 2. Further, a given column of the P matrix can correspond to the time interval duration Tl, T2, T3, and T4.

[0052] FIG. 3 shows a diagram 300 of a definition for the channel estimation subfield (CEi) in accordance with example embodiments of the disclosure. In one embodiment, the CEi's can be composed of Gu and GV\N sequences (302 and 304, respectively) and -Gb^ sequence 306 at the end of the frame, where the index i can define spatial stream number and sub-index 4N or N can define the corresponding sequence length.

[0053] The sequences GU\N and GV\N can be defined as follows:

where each pair (Ga^, GbV) can be a Golay complementary pair of sequences of length N. In one embodiment, different spatial stream i can use different pair of sequences (Ga^, Gb _N ). Moreover, the sequences can be of different length N. In an embodiment, the length N can be calculated as: N = NCB * 128, where NCB can represent the CB factor, and can be equal to, in some embodiments, any arbitrary positive integer. In one embodiment, the set of Golay sequences (Ga^, Gb^) for the lengths N = 128, 256, 384, and 512 and i = 1 :8 can be referred to as a Golay Sequence Set (GSS).

[0054] FIG. 4 shows a diagram 400 of an example extension of the EDMG CEF design to the time domain as well as the frequency domain in accordance with example embodiments of the disclosure. In one embodiment, the extensions to the EDMG CEF design can be denoted as CE' to signify the extended channel estimation subfield, in distinction to the CE fields shown and described in connection with FIG. 2. In one embodiment, the extension of the EDMG CEF affects time intervals T2, T3, and T4 and may not affect the time interval Tl . In one embodiment, the definitions of the EDMG CEF for SC MIMO can apply for NSS > 2.

[0055] In particular, the design can permit channel estimation for Single Carrier (SC) MIMO using 8 spatial streams in accordance with example embodiments of the disclosure. In one embodiment, the duration of the extended EDMG CEF field can depend on the actual number of spatial streams (NSS). In an embodiment, for 2 streams the EDMG CEF duration can be equal to time interval T = Tl, as shown by group 402. [0056] In another embodiment, for NSS = 3 or 4, the EDMG CEF duration can be equal to 2 time intervals, that is, T = Tl + T2, as shown by groups 404 and 406. In one embodiment, for NSS = 5 through NSS = 8, the EDMG CEF duration can be equal to 4 time intervals, that is, T = Tl + T2 + T3 + T4, as shown by groups 408 and 410.

[0057] In a further embodiment, the EDMG CEF field can include a number of channel estimation (denoted CEi and CE'i where i represents an integer) subfields. In one embodiment, the channel estimation subfields can also depend on the number of spatial streams (NSS). In an embodiment, for 2 streams the channel estimation can be performed by using CEI and CE2, as shown by group 402. In another embodiment, for NSS = 3 streams the channel estimation can be performed by using CEI, CE2, CE3, CE' I, CE'2, CE'3, and - CE'3 as shown by group 404. In one embodiment, for NSS = 4 streams the channel estimation can be performed by using CEI, CE2, CE3, CE4, CE' I, CE'2, -CE'3, CE'3, - CE'4, and CE'4 as shown by group 406. In one embodiment, for NSS = 5 streams the channel estimation can be performed by using CEI, CE2, CE3, CE4, CE5, CE' I, CE'2, CE'3, -CE'3, CE'4, -CE'4, CE'5, and -CE'5 as shown by group 408. In one embodiment, for NSS = 5 streams the channel estimation can be performed by using CEI, CE2, CE3, CE4, CE5, CE6, CE' I, CE'2, CE'3, CE'4, CE'5, CE'6 as shown by group 408.

[0058] In one embodiment, for NSS = 5 through 8 streams the channel estimation can be performed by using CEI, CE2, CE3, CE4, CE5, CE6, CE7, CE8, CE' I, CE'2, CE'3, - CE'3, CE'4, -CE'4, CE'5, - CE'5, CE'6, -CE'6, CE'7, -CE'7, CE'8, and -CE'8 as shown by group 410.

[0059] FIGs. 5A, 5B, 5C, 5D, 5E, 5F, 5G, 5H, 51, 5J, 5K, 5L, 5M, 5N, 50, and 5P show example CE subfields, in accordance with example embodiments of the disclosure.

[0060] FIG. 5A shows a diagram 500 of an example extended EDMG CEF subfield in accordance with example embodiments of the disclosure. In one embodiment, the CE's can be composed of sequences (504 and 506, respectively) and -Gb N sequence 508 at the end of the frame, where the index i can define spatial stream number and sub-index 4N or N can define the corresponding sequence length. In one embodiment, the defined CE'i may have an additional -Ga _N sequence 502 as a prefix, which can serve to distinguish the field from the legacy subfield. In one embodiment, the introduction of this extra -Ga^ sequence 502 can permit a more accurate channel estimation in the time domain and/or frequency domain. [0061] FIG. 5B shows a diagram 501 of an example extended EDMG CEF subfield for 1 stream, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 5B element 501, the CEF can include a Gu ¹ 1024 field, a Gv ¹ 1024 field, and a - Gb \ ₅₆ field; the CEF can have a duration having a value approximately equal to 2304*Tc/2.

[0062] FIG. 5C shows a diagram 503 of an example extended EDMG CEF subfield for 1 stream, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 5C element 503, the CEF can include a Gu ¹ 2048 field, a Gv ¹ 2048 field, and a - Go ¹ in field; the CEF can have a duration having a value approximately equal to 4608*Tc/4.

[0063] FIG. 5D shows a diagram 507 of an example extended EDMG CEF subfield for 1 stream, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 5D element 507, the CEF can include a Gu ₁ e field, a Gv ¹ ΐ536 field, and a - Gb ¹ 384 field; the CEF can have a duration having a value approximately equal to 3456*Tc/3.

[0064] FIG. 5E shows a diagram 509 of an example extended EDMG CEF subfield for 2 streams, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 5E element 509, the CEF can include a Gu ₁ field, a Gv ¹ su field, and a -Gb ¹ ₁ 28 field for ISTS = 1; the CEF can include a Gu ² 512 field, a Gv ² 512 field, and a -Gb ² us field for ISTS = 2; the CEF can have a duration having a value approximately equal to 1152*Tc.

[0065] FIG. 5F shows a diagram 511 of an example extended EDMG CEF subfield for 2 streams, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 5F element 511, the CEF can include a Gu ¹ 1024 field, a Gv ¹ ^ field, and a -Gb ¹ 256 field for ISTS = 1 ; the CEF can include a Gu ² 1024 field, a Gv ² 1024 field, and a -Gb ² 256 field for ISTS = 2; the CEF can have a duration having a value approximately equal to 2304*(Tc/2).

[0066] FIG. 5G shows a diagram 513 of an example extended EDMG CEF subfield for 2 streams, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 5G element 513, the CEF can include a Gu ₁ e field, a Gv ¹ ΐ536 field, and a - Gb ^X 384 field for ISTS = 1 ; the CEF can include a Gu ² 1536 field, a Gv ² 1536 field, and a -Gb ² 384 field for ISTS = 2; the CEF can have a duration having a value approximately equal to 3456*(Tc/3).

[0067] FIG. 5H shows a diagram 515 of an example extended EDMG CEF subfield for 2 streams, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 5H element 515, the CEF can include a Gu ¹ 2048 field, a Gv ¹ 2048 field, and a - Gb ¹ 5u field for ISTS = 1 ; the CEF can include a Gu ² 2048 field, a Gv ² 2048 field, and a -Gb ² su field for ISTS = 2; the CEF can have a duration having a value approximately equal to 4608*(Tc/4).

[0068] FIG. 51 shows a diagram 517 of an example extended EDMG CEF subfield for 4 streams, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 51 element 517, the CEF can include a Gu^ o field, a Gv ¹ su field, a -Gb ¹ ₁ 28 field, a -Ga ¹ ^ field, a Gu^o field, a Gv ^ ₁₂ field, and a -Gb^s for ISTS = 1 ; the CEF can

2 2 2 2 2 2 include a Gu 512 field, a Gv 512 field, a -Gb 128 field, a -Ga 128 field, a Gu 512 field, a Gv 512 field, and a -Gb ² 128 for ISTS = 2; the CEF can include a Gu ³ 512 field, a Gv ³ 512 field, a -Gb ³ i28 field, a Ga ³ 128 field, a -Gu ³ 512 field, a -Gv ³ su field, and a Gb ³ 128 for ISTS = 3; the CEF can include a Gu ⁴ 512 field, a Gv ⁴ 512 field, a -Gb ⁴ 128 field, a Ga ⁴ 128 field, a -Gu ⁴ 512 field, a -Gv ⁴ ¾i2 field, and a Gb ⁴ 128 for ISTS = 4; the CEF can have a duration having a value approximately equal to 2432*Tc.

[0069] FIG. 5 J shows a diagram 519 of an example extended EDMG CEF subfield for 4 streams, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 5J element 519, the CEF can include a Gu ¹ 1024 field, a Gv ¹ ^ field, a -Gb ¹ 2se field, a -Ga^se field, a Gu ¹ 1024 field, a Gv ^X 1024 field, and a -Gb^se for ISTS = 1 ; the CEF can include a Gu 1024 field, a Gv 1024 field, a -Gb 256 field, a -Ga 256 field, a Gu 1024 field, a Gv ² 1024 field, and a -Gb ² 256 for ISTS = 2; the CEF can include a Gu ³ 1024 field, a Gv ³ 1024 field, a - Gb 256 field, a Ga 256 field, a -Gu 1024 field, a -Gv 1024 field, and a Gb 256 for ISTS = 3; the CEF can include a Gu ⁴ 1024 field, a Gv ⁴ 1024 field, a -Gb ⁴ 256 field, a Ga ⁴ 256 field, a -Gu ⁴ 1024 field, a -Gv ⁴ 1024 field, and a Gb ⁴ 256 for ISTS = 4; the CEF can have a duration having a value approximately equal to 4864*(Tc/2).

[0070] FIG. 5K shows a diagram 521 of an example extended EDMG CEF subfield for 4 streams, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 5K element 521, the CEF can include a Gu ₁ 1536 field, a Gv ¹ ΐ536 field, a -Gb ^84 field, a -Ga ¹ 384 field, a Gu ¹ 1536 field, a Gv ¹ ₁ 536 field, and a -Gb^ for ISTS = 1 ; the CEF can

2 2 2 2 2 include a Gu 1536 field, a Gv i ₅₃₆ field, a -Gb 384 field, a -Ga 384 field, a Gu 1536 field, a Gv ² 1536 field, and a -Gb ² 384 for ISTS = 2; the CEF can include a Gu ³ 1536 field, a Gv ³ 1536 field, a -

3 3 3 3 3

Gb 384 field, a Ga 384 field, a -Gu 1536 field, a -Gv 1536 field, and a Gb 384 for ISTS = 3; the CEF can include a Gu ⁴ 1536 field, a Gv ⁴ 1536 field, a -Gb %4 field, a Ga ⁴ 384 field, a -Gu ⁴ 1536 field, a -Gv ⁴ 1536 field, and a Gb ⁴ 384 for ISTS = 4; the CEF can have a duration having a value approximately equal to 6912*(Tc/3).

[0071] FIG. 5L shows a diagram 523 of an example extended EDMG CEF subfield for 4 streams, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 5L element 523, the CEF can include a GU^IMS field, a Gv ¹ 2048 field, a -Gb ^ ₁₂ field, a -Ga^o field, a GU^IMS field, a Gv ^X 2048 field, and a -Gb^ for ISTS = 1 ; the CEF can

2 2 2 2 2 include a Gu 2048 field, a Gv 2048 field, a -Gb 512 field, a -Ga 512 field, a Gu 2048 field, a Gv ² 2048 field, and a -Gb ² 512 for ISTS = 2; the CEF can include a Gu ³ 2048 field, a Gv ³ 2048 field, a -

3 3 3 3 3

Gb 512 field, a Ga 512 field, a -Gu 2048 field, a -Gv 2048 field, and a Gb 512 for ISTS = 3; the CEF can include a Gu ⁴ 2048 field, a Gv ⁴ 2048 field, a -Gb ⁴ ¾ i2 field, a Ga ⁴ 512 field, a -Gu ⁴ 2048 field, a -Gv %48 field, and a Gb ⁴ 512 for ISTS = 4; the CEF can have a duration having a value approximately equal to 9728*(Tc/4).

[0072] FIG. 5M shows a diagram 525 of an example extended EDMG CEF subfield for 8 streams, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 5M element 525, the CEF can include a Gu ₁ field, a Gv ¹ su field, a -Gb ¹ i28 field, a -Ga ¹ 128 field, a Gu ₁ field, a Gv^ field, a -Gb ¹ 128 , a -Ga ¹ ₁₂₈ field, a Gu^o field, a Gv^ field, a -Gb^s field, a -Ga ¹ 128 field, a Gu ₁ field, a Gv^ field, and a -Gb ¹ 128 for ISTS = 1 ; the CEF can include a Gu ² 512 field, a Gv ² 512 field, a -Gb ² 128 field, a -Ga ² 128 field, a Gu 512 field, a Gv 512 field, a -Gb 128 , a -Ga 128 field, a Gu 512 field, a Gv 512 field, a -Gb 128 field, a -Ga ² 128 field, a Gu ² 512 field, a Gv ² 512 field, and a -Gb ² 128 for ISTS = 2; the CEF can include a Gu 512 field, a Gv 512 field, a -Gb 128 field, a -Ga 128 field, a -Gu 512 field, a -

3 3 3 3 3 3 3

Gv 512 field, a -Gb 128 , a -Ga 128 field, a Gu 512 field, a Gv 512 field, a -Gb 128 field, a Ga 128 field, a -Gu ³ 512 field, a -Gv ³ 512 field, and a Gb ³ 128 for ISTS = 3; the CEF can include a Gu ⁴ 512 field, a Gv ⁴ 512 field, a -Gb ⁴ 128 field, a -Ga ⁴ 128 field, a -Gu ⁴ 512 field, a -Gv ⁴ 512 field, a - Gb ⁴ 128 , a -Ga ⁴ 128 field, a Gu ⁴ 512 field, a Gv ⁴ 512 field, a -Gb ⁴ 128 field, a Ga ⁴ 128 field, a -Gu ⁴ 512 field, a -Gv ⁴ 512 field, and a Gb ⁴ 128 for ISTS = 4; the CEF can include a Gu ⁵ 512 field, a Gv ⁵ 512 field, a -Gb ⁵ 128 field, a -Ga ⁵ i ₂ 8 field, a Gu ⁵ ₅ i2 field, a Gv ⁵ ₅ i2 field, a -Gb ⁵ i ₂ 8 , a Ga ⁵ i ₂ 8 field, a -Gu ⁵ 512 field, a -Gv ⁵ ₅ i2 field, a Gb ⁵ i ₂ 8 field, a Ga ⁵ i ₂ 8 field, a -Gu ⁵ ₅ i ₂ field, a -Gv ⁵ ₅ i2 field, and a Gb ⁵ 128 for ISTS = 5; the CEF can include a Gu ⁶ 512 field, a Gv ⁶ 512 field, a -Gb ⁶ 128 field, a -Ga ⁶ 128 field, a Gu ⁶ 512 field, a Gv ⁶ 512 field, a -Gb ⁶ 128 , a Ga ⁶ 128 field, a -Gu ⁶ 512 field, a - Gv ⁶ 512 field, a Gb ⁶ 128 field, a Ga ⁶ 128 field, a -Gu ⁶ 512 field, a -Gv ⁶ 512 field, and a Gb ⁶ 128 for ISTS = 6; the CEF can include a Gu ⁷ 512 field, a Gv ⁷ 512 field, a -Gb ⁷ 128 field, a Ga ⁷ 128 field, a -

Gu 512 field, a -Gv 512 field, a Gb 128 , a Ga 128 field, a -Gu 512 field, a -Gv 512 field, a Gb 128 field, a -Ga ⁷ 128 field, a Gu ⁷ 512 field, a Gv ⁷ 512 field, and a -Gb ⁷ 128 for ISTS = 7; the CEF can include a Gu ⁸ 512 field, a Gv ⁸ 512 field, a -Gb ⁸ 128 field, a Ga ⁸ 128 field, a -Gu ⁸ 512 field, a -Gv ⁸ 512 field, a Gb ⁸ 128 , a Ga ⁸ 128 field, a -Gu ⁸ 512 field, a -Gv ⁸ 512 field, a Gb ⁸ 128 field, a -Ga ⁸ 128 field, a Gu ⁸ 512 field, a Gv ⁸ 512 field, and a -Gb ⁸ 128 for ISTS = 8; the CEF can have a duration having a value approximately equal to 4992*Tc.

[0073] FIG. 5N shows a diagram 527 of an example extended EDMG CEF subfield for 8 streams, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 5N element 527, the CEF can include a Gu ¹ 1024 field, a Gv ¹ ^ field, a -Gb ¹ ^ field, a -Ga ¹ ^ field, a Gu ¹ 1024 field, a Gv ¹ ιο24 field, a -Gb ¹ ^ , a -Ga ¹ ^ field, a Gu ¹ 1024 field, a Gv ¹ ^ field, a -Gb ¹ ^ field, a -Ga ¹ ^ field, a Gu ¹ 1024 field, a Gv ¹ ^ field, and a - Gb^ for ISTS = 1 ; the CEF can include a Gu ² 1024 field, a Gv ² 1024 field, a -Gb ² 256 field, a -

2 2 2 2 2 2

Ga 256 field, a Gu 1024 field, a Gv 1024 field, a -Gb 256 , a -Ga 256 field, a Gu 1024 field, a

2 2 2 2 2 2

Gv 1024 field, a -Gb 256 field, a -Ga 256 field, a Gu 1024 field, a Gv 1024 field, and a -Gb 256 for ISTS = 2; the CEF can include a Gu ³ 1024 field, a Gv ³ 1024 field, a -Gb ³ 256 field, a -Ga ³ 256

3 3 3 3 3 3 field, a -Gu 1024 field, a -Gv 1024 field, a -Gb 256 , a -Ga 256 field, a Gu 1024 field, a Gv 1024 field, a -Gb ³ 256 field, a Ga ³ 256 field, a -Gu ³ 1024 field, a -Gv ³ 1024 field, and a Gb ³ 256 for ISTS = 3; the CEF can include a Gu ⁴ 1024 field, a Gv ⁴ 1024 field, a -Gb ⁴ 256 field, a -Ga ⁴ 256 field, a - Gu ⁴ 1024 field, a -Gv ⁴ 1024 field, a -Gb ⁴ 256 , a -Ga ⁴ 256 field, a Gu ⁴ 1024 field, a Gv ⁴ 1024 field, a - Gb ⁴ 256 field, a Ga ⁴ 256 field, a -Gu ⁴ 1024 field, a -Gv ⁴ 1024 field, and a Gb ⁴ 256 for ISTS = 4; the CEF can include a Gu ⁵ 1024 field, a Gv ⁵ 1024 field, a -Gb ⁵ 256 field, a -Ga ⁵ 256 field, a Gu ⁵ 1024 field, a Gv ⁵ 1024 field, a -Gb ⁵ 256 , a Ga ⁵ 256 field, a -Gu ⁵ 1024 field, a -Gv ⁵ 1024 field, a Gb ⁵ 256 field, a Ga ⁵ 256 field, a -Gu ⁵ 1024 field, a -Gv ⁵ 1024 field, and a Gb ⁵ 256 for ISTS = 5; the CEF can include a Gu ⁶ 1024 field, a Gv ⁶ 1024 field, a -Gb ⁶ 256 field, a -Ga ⁶ 256 field, a Gu ⁶ 1024 field, a Gv ⁶ 1024 field, a -Gb ⁶ 256 , a Ga ⁶ 256 field, a -Gu ⁶ 1024 field, a -Gv ⁶ 1024 field, a Gb ⁶ 256 field, a Ga ⁶ 256 field, a -Gu ⁶ 1024 field, a -Gv ⁶ 1024 field, and a Gb ⁶ 256 for ISTS = 6; the CEF can include a Gu ⁷ 1024 field, a Gv ⁷ 1024 field, a -Gb ⁷ 256 field, a Ga ⁷ 256 field, a -Gu ⁷ 1024 field, a -Gv ⁷ 1024 field, a Gb ⁷ 256 , a Ga ⁷ 256 field, a -Gu ⁷ 1024 field, a -Gv ⁷ 1024 field, a Gb ⁷ 256 field, a -Ga ⁷ 256 field, a Gu ⁷ 1024 field, a Gv ⁷ 1024 field, and a -Gb ⁷ 256 for ISTS = 7; the CEF can include a Gu ⁸ 1024 field, a Gv ⁸ 1024 field, a -Gb ⁸ 256 field, a Ga ⁸ 256 field, a -Gu ⁸ 1024 field, a -Gv ⁸ 1024 field, a Gb ⁸ 256 , a Ga ⁸ 256 field, a -Gu ⁸ 1024 field, a -Gv ⁸ 1024 field, a Gb ⁸ 256 field, a -Ga ⁸ 256 field, a Gu ⁸ 1024 field, a Gv ⁸ 1024 field, and a -Gb ⁸ 256 for ISTS = 8; the CEF can have a duration having a value approximately equal to 9984*(Tc/2). [0074] FIG. 50 shows a diagram 529 of an example extended EDMG CEF subfield for 8 streams, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 50 element 529, the CEF can include a Gu ¹ 1536 field, a Gv ¹ 1536 field, a -Gb ¹ 384 field, a -Ga ¹ 384 field, a Gv ¹ 1536 field, a Gv ¹ 1536 field, a -Gb ¹ 384 , a -Ga ¹ 384 field, a Gu ¹ 1536 field, a Gv ¹ 1536 field, a -Gb ¹ 384 field, a -Ga ¹ 384 field, a Gu ¹ 1536 field, a Gv ¹ 1536 field, and a - Gb ¹ 384 for isTS = 1; the CEF can include a Gu ² 1536 field, a Gv ² 1536 field, a -Gb ² 384 field, a - Ga ² 384 field, a Gu ² 1536 field, a Gv ² 1536 field, a -Gb ² 384 , a -Ga ² 384 field, a Gu ² 1536 field, a Gv ² 1536 field, a -Gb ² 384 field, a -Ga ² 384 field, a Gu ² 1536 field, a Gv ² 1536 field, and a -Gb ² 384 for isTS = 2; the CEF can include a Gu ³ 1536 field, a Gv ³ 1536 field, a -Gb ³ 384 field, a -Ga ³ 384 field, a -Gu ³ 1536 field, a -Gv ³ 1536 field, a -Gb ³ 384 , a -Ga ³ 384 field, a Gu ³ 1536 field, a Gv ³ 1536 field, a -Gb ³ 384 field, a Ga ³ 384 field, a -Gu ³ 1536 field, a -Gv ³ 1536 field, and a Gb ³ 384 for ISTS = 3; the CEF can include a Gu ⁴ 1536 field, a Gv ⁴ 1536 field, a -Gb ¹ 384 field, a -Ga ⁴ 384 field, a - Gu ⁴ 1536 field, a -Gv ⁴ 1536 field, a -Gb ⁴ 384 , a -Ga ¹ 384 field, a Gu ⁴ 1536 field, a Gv ⁴ 1536 field, a - Gb ⁴ 384 field, a Ga ⁴ 384 field, a -Gu ⁴ 1536 field, a -Gv ⁴ 1536 field, and a Gb ⁴ 384 for ISTS = 4; the CEF can include a Gu ⁵ 1536 field, a Gv ⁵ 1536 field, a -Gb ⁵ 384 field, a -Ga ⁵ 384 field, a Gu ⁵ 1536 field, a Gv ⁵ 1536 field, a -Gb ⁵ 384 , a Ga ⁵ 384 field, a -Gu ⁵ 1536 field, a -Gv ⁵ 1536 field, a Gb ⁵ 384 field, a Ga ^S 384 field, a -Gu ⁵ 1536 field, a -Gv ⁵ 1536 field, and a Gb ⁵ 384 for ISTS = 5; the CEF can include a Gu ⁶ 1536 field, a Gv ⁶ 1536 field, a -Gb ⁶ 384 field, a -Ga ⁶ 384 field, a Gu ⁶ 1536 field, a Gv ⁶ 1536 field, a -GbV , a Ga ⁶ _3g 4 field, a -Gu ⁶ 1536 field, a -Gv ⁶ 1536 field, a Gb ⁶ 384 field, a Ga ⁶ 384 field, a -Gu ⁶ 1536 field, a -Gv ⁶ 1536 field, and a Gb ⁶ 384 for ISTS = 6; the CEF can include a Gu ⁷ 1536 field, a Gv ⁷ 1536 field, a -Gb ⁷ 384 field, a Ga ⁷ 384 field, a -Gu ⁷ 1536 field, a -Gv ⁷ 1536 field, a Gb ⁷ 384 , a Ga ⁷ 384 field, a -Gu ⁷ 1536 field, a -Gv ⁷ 1536 field, a Gb ⁷ 384 field, a -Ga ⁷ 384 field, a Gu ⁷ 1536 field, a Gv ⁷ 1536 field, and a -Gb ⁷ 384 for ISTS = 7; the CEF can include a Gu ⁸ 1536 field, a Gv ⁸ 1536 field, a -Gb ¹ 384 field, a Ga ⁸ 384 field, a -Gu ⁸ 1536 field, a -Gv ⁸ 1536 field, a Gb ⁸ 384 , a Ga ⁸ 384 field, a -Gu ⁸ 1536 field, a -Gv ⁸ 1536 field, a Gb ¹ 384 field, a -Ga ⁸ 384 field, a Gu ⁸ 1536 field, a Gv ⁸ 1536 field, and a -Gb ⁸ 384 for ISTS = 8; the CEF can have a duration having a value approximately equal to 14976*(Tc/3).

[0075] FIG. 5P shows a diagram 531 of an example extended EDMG CEF subfield for 8 streams, in accordance with example embodiments of the disclosure. In one embodiment, as shown in FIG. 5P element 531, the CEF can include a Gu ¹ 2048 field, a Gv ¹ 2048 field, a -Gb ¹ 512 field, a -Ga ¹ 512 field, a Gu ¹ 2048 field, a Gv ¹ 2048 field, a -Gb ¹ 512 , a -Ga ¹ 512 field, a Gu ¹ 2048 field, a Gv ¹ 2048 field, a -Gb ¹ 512 field, a -Ga ¹ 512 field, a Gu ¹ 2048 field, a Gv ¹ 2048 field, and a - Gb^ for isTS = 1 ; the CEF can include a Gu ² 2048 field, a Gv ² 2048 field, a -Gb ² 512 field, a -

2 2 2 2 2 2

Ga 512 field, a Gu 2048 field, a Gv 2048 field, a -Gb 512 , a -Ga 512 field, a Gu 2048 field, a Gv 2048 field, a -Gb 512 field, a -Ga 512 field, a Gu 2048 field, a Gv 2048 field, and a -Gb 512 for isTS = 2; the CEF can include a Gu ³ 2048 field, a Gv ³ 2048 field, a -Gb ³ 512 field, a -Ga ³ 512 field, a -Gu 2048 field, a -Gv 2048 field, a -Gb 512 , a -Ga 512 field, a Gu 2048 field, a Gv 2048 field, a -Gb ³ 512 field, a Ga ³ 512 field, a -Gu ³ 2048 field, a -Gv ³ 2048 field, and a Gb ³ 512 for ISTS = 3; the CEF can include a Gu ⁴ 2048 field, a Gv ⁴ 2048 field, a -Gb ⁴ 512 field, a -Ga ⁴ 512 field, a - Gu ⁴ 2048 field, a -Gv ⁴ 2048 field, a -Gb ⁴ 512 , a -Ga ⁴ 512 field, a Gu ⁴ 2048 field, a Gv ⁴ 2048 field, a - Gb ⁴ 512 field, a Ga ⁴ 512 field, a -Gu ⁴ 2048 field, a -Gv ⁴ 2048 field, and a Gb ⁴ 512 for ISTS = 4; the CEF can include a Gu ⁵ 2048 field, a Gv ⁵ 2048 field, a -Gb ⁵ 512 field, a -Ga ⁵ 512 field, a Gu ⁵ 2048 field, a Gv ⁵ 2048 field, a -Gb ⁵ 512 , a Ga ⁵ 512 field, a -Gu ⁵ 2048 field, a -Gv ⁵ 2048 field, a Gb ⁵ 512 field, a Ga ⁵ 512 field, a -Gu ⁵ 2048 field, a -Gv ⁵ 2048 field, and a Gb ⁵ 512 for ISTS = 5; the CEF can include a Gu ⁶ 2048 field, a Gv ⁶ 2048 field, a -Gb ⁶ 512 field, a -Ga ⁶ 512 field, a Gu ⁶ 2048 field, a Gv ⁶ 2048 field, a -Gb ⁶ 512 , a Ga ⁶ 512 field, a -Gu ⁶ 2048 field, a -Gv ⁶ 2048 field, a Gb ⁶ 512 field, a Ga ⁶ 512 field, a -Gu ⁶ 2048 field, a -Gv ⁶ 2048 field, and a Gb ⁶ 512 for ISTS = 6; the CEF can include a Gu ⁷ 2048 field, a Gv ⁷ 2048 field, a -Gb ⁷ 512 field, a Ga ⁷ 512 field, a -Gu ⁷ 2048 field, a -Gv ⁷ 2048 field, a Gb ⁷ 512 , a Ga ⁷ 512 field, a -Gu ⁷ 2048 field, a -Gv ⁷ 2048 field, a Gb ⁷ 512 field, a -Ga ⁷ 512 field, a Gu ⁷ 2048 field, a Gv ⁷ 2048 field, and a -Gb ⁷ 512 for ISTS = 7; the CEF can include a Gu ⁸ 2048 field, a Gv ⁸ 2048 field, a -Gb ⁸ 512 field, a Ga ⁸ 512 field, a -Gu ⁸ 2048 field, a -Gv ⁸ 2048 field, a Gb ⁸ 512 , a Ga ⁸ 512 field, a -Gu ⁸ ₂₀₄ 8 field, a -Gv ⁸ ₂₀₄ 8 field, a Gb ⁸ ₅ i ₂ field, a -Ga ⁸ ₅ i ₂ field, a Gu ⁸ 2048 field, a Gv ⁸ 2048 field, and a -Gb ⁸ 512 for ISTS = 8; the CEF can have a duration having a value approximately equal to 19968*(Tc/4).

[0076] FIG. 6 shows a plot 600 of an example of correlator output for the CEi legacy subfield as shown and described in connection with FIG. 3, that is, the CEi subfield not having an additional -Ga _N sequence for N = 128, in accordance with example embodiments of the disclosure. In one embodiment, the plot 600 shows the amplitude of the correlator output 602 on the y-axis of the plot 600 versus the number of samples 604 on the x-axis of the plot 600. It may be noted that the correlator response, while showing a peak 610, may not represent a pure delta Dirac function 5(n-128), where n represents the samples. That is, there may be a ripple 608, for example, for index n + 128. The ripple 608 may lead to Intersymbol Interference (ISI) and may affect channel estimation. In one embodiment, the ripple and therefore, the ISI can be reduced by introduction of an additional sequence -GaOs, as is shown and described further in connection with FIG. 7, below.

[0077] FIG. 7 shows a plot 700 of an example of correlator output for the CE'i subfield as shown and described in connection with FIG. 5, where the CE'i subfield has an additional -Ga N sequence for N = 128, in accordance with example embodiments of the disclosure. In one embodiment, the plot 700 shows the amplitude of the correlator output 702 on the y-axis of the plot 700 versus the number of samples 704 on the x-axis of the plot 700. It may be noted that the correlator response in that case represent a pure delta function showing a peak 710 with zero or near zero ripple in region 708 of the plot 700, which can lead to better channel estimation. In one embodiment, the extra -GaN sequence nay be not required for the first CEi subfield (that is, CE1) in FIG. 4, for example, because the -GaN sequence may be present in the EDMG short training field (STF), which can precede the EDMG CEF field in the general frame structure.

[0078] FIG. 8 show a diagram of an example flow chart 800 in accordance with one or more example embodiments of the disclosure. In one embodiment, the flow chart can be used in connection with a transmitting device (for example, an Access Point, AP) on a wireless network

[0079] In block 802, a device (e.g., the user device(s) 120 and/or the AP 102 of FIG. 1) may cause to establish or determine to establish one or more multiple-input and multiple- output (MIMO) communication channels between the device and a plurality of devices. The establishment of the MIMO communications channels may first involve a determination of data by the device to send to one or more devices of the plurality of devices. This determination of the data to send may be made, for example, based on a user input to the device, a predetermined schedule of data transmissions on the network, changes in network conditions, and the like. The establishment of the MIMO communications channels may further involve the transmission of one or more data packets (for example, one or more Request to Send (RTS)) to notify the one or more devices of the plurality of devices to establish the communications channel. In one embodiment, the establishment of the MIMO communications channels may be performed in accordance with one or more wireless and/or network standards.

[0080] In block 804, the device may determine channel estimation fields (CEFs) and/or extended CEF fields for channel estimation of at least one of the one or more MIMO communications channels in a time domain. In various embodiments, the generation of the CEFs and/or extended CEFs can be based in part on the determination of one or more Golay complementary sequences. In one embodiment, the CEFs and/or extended CEFs can be used in the context of one or more standards, for example, an 802. 1 1 ay standard, for SC MIMO channel estimation. In one embodiment, the CEFs and/or extended CEFs can use Golay complementary sequences. In another embodiment, the Golay complementary sequences, for example, Ga/Gb can be defined similar to Golay complementary sequences definitions that can be found in various standards, for example, a legacy 802. 1 1 ad standard. Various embodiments the CEFs and/or extended CEFs can be used for channel estimation of M x N MIMO configurations, where M and N are positive integers.

[0081] In one embodiment, the extended CEF fields can be composed of

sequences (such as those shown and described in connection with FIG. 5, for example, elements 504 and 506) and -Gb N sequence (as shown and described in connection with FIG. 5 element 508) at the end of the frame, where the index i can define spatial stream number and sub-index 4N or N can define the corresponding sequence length. In one embodiment, the extended CEF fields may have an additional -GaN sequence (for example, as shown and described in connection with FIG. 5 element 502) as a prefix, which can serve to distinguish the field from the legacy, non-extended subfield. In one embodiment, the introduction of this extra -Ga^ sequence can permit a more accurate channel estimation in the time domain and/or frequency domain. [0082] In block 806, the device may cause to send CEFs and/or extended CEFs to one or more of the plurality of devices. In one embodiment, the one or more CEFs may be encapsulated in a data frame that is sent from the device to one or more of the plurality of devices. In another embodiment, CEFs and/or extended CEFs may be sent in a header of the data frame. In one embodiment, the CEFs and/or extended CEFs may be sent at a predetermined time based at least in part on a predetermined schedule of communication between the devices of the network. In another embodiment, first CEFs and/or extended CEFs may be first sent by the device, a period of time may elapse, and the device may repeat some or all of the procedures described in connection with block 804, and resend second CEFs and/or extended CEFs. In one embodiment during, or after the transmission of the CEFs and/or extended CEFs, the device may receive information from the receiving device, indicative of a change to be performed by the transmitting device in sending data. For example, the information may indicate to change the number of streams of the MIMO communications channels, to increase and/or decrease the amount of data transmitted on one or more channels of the MIMO communications channels, to retransmit one or more packets of data, to send one or more packets of data at a predetermined time, and the like.

[0083] FIG. 9 show a diagram of an example flow chart 900 in accordance with one or more example embodiments of the disclosure. In one embodiment, the flow chart can be used in connection with a receiving device (for example, a wireless Source (SRC) station (STA)) on a wireless network.

[0084] In block 902, a device (e.g., the user device(s) 120 and/or the AP 102 of FIG. 1) may cause to establish one or more MIMO communication channels between the device and a second device. The establishment of the MIMO communications channels may first involve a determination of data by the device to send to the second device. This determination of the data to send may be made, for example, based on a user input to the device or the second device, a predetermined schedule of data transmissions on the network, changes in network conditions, and the like. The establishment of the MIMO communications channels may further involve the transmission of one or more data packets (for example, one or more Clear to Send (CTS)) to notify the second device of one or more conditions related to the establishment of the communications channels. The establishment of the MIMO communications channels may be performed in accordance with one or more wireless and/or network standards.

[0085] In block 904, the device can receive CEFs and/or extended CEFs, from the second device, for channel estimation of at least one of the one or more MIMO communication channels in a time domain or frequency domain. In one embodiment, the CEFs may be encapsulated in a data frame. In another embodiment, CEFs and/or extended CEFs may be sent in a header of the data frame. In one embodiment, the CEFs and/or extended CEFs may be sent at a predetermined time based at least in part on a predetermined schedule of communication between the devices of the network. In another embodiment, first CEFs and/or extended CEFs may be first received by the device, a period of time may elapse, and second CEFs and/or extended CEFs may be received by the device. The second CEFs and/or extended CEFs can thereby reflect changes in the condition of the channel(s) or device(s) over time.

[0086] In one embodiment, the extended CEF fields can be composed of and GV\N sequences (such as those shown and described in connection with FIG. 5, for example, elements 504 and 506) and -Gb N sequence (as shown and described in connection with FIG. 5 element 508) at the end of the frame, where the index i can define spatial stream number and sub-index 4N or N can define the corresponding sequence length. In one embodiment, the extended CEF fields may have an additional -GaN sequence (for example, as shown and described in connection with FIG. 5 element 502) as a prefix, which can serve to distinguish the field from the legacy, non-extended subfield. In one embodiment, the introduction of this extra -Ga^ sequence can permit a more accurate channel estimation in the time domain and/or frequency domain. [0087] In block 906, the device can cause to send first information to the second device based at least in part on the CEFs and/or extended CEFs. In one embodiment during, or after the reception of the first or second CEFs and/or extended CEFs, the device may determine the first information, the information indicative of a change to be performed by the transmitting device in sending data. For example, the first information may indicate to the second device to change the number of streams of the MIMO communications channels, to increase and/or decrease the amount of data transmitted on one or more channels of the MIMO communications channels, to retransmit one or more packets of data, to send one or more packets of data at a predetermined time, and the like.

[0088] FIG. 10 shows a functional diagram 1000 of an example communication station 1000 in accordance with some embodiments. In one embodiment, FIG. 10 illustrates a functional block diagram of a communication station that may be suitable for use as an AP 102 (FIG. 1) or communication station user device 120 (FIG. 1) in accordance with some embodiments. The communication station 1000 may also be suitable for use as a handheld device, mobile device, cellular telephone, smartphone, tablet, netbook, wireless terminal, laptop computer, wearable computer device, femtocell, High Data Rate (HDR) subscriber station, access point, access terminal, or other personal communication system (PCS) device.

[0089] The communication station 1000 may include communications circuitry 1002 and a transceiver 1010 for transmitting and receiving signals to and from other communication stations using one or more antennas 1001. The communications circuitry 1002 may include circuitry that can operate the physical layer communications and/or medium access control (MAC) communications for controlling access to the wireless medium, and/or any other communications layers for transmitting and receiving signals. The communication station 1000 may also include processing circuitry 1006 and memory 1008 arranged to perform the operations described herein. In some embodiments, the communications circuitry 1002 and the processing circuitry 1006 may be configured to perform operations detailed in FIGs. 1 -9.

[0090] The communication station 1000 may include communications circuitry 1002 and a transceiver 1010 for transmitting and receiving signals to and from other communication stations using one or more antennas 1001. The transceiver 1010 may be a device comprising both a transmitter and a receiver that are combined and share common circuitry (e.g., communication circuitry 1002). The communication circuitry 1002 may include amplifiers, filters, mixers, analog to digital and/or digital to analog converters. The transceiver 1010 may transmit and receive analog or digital signals. The transceiver 1010 may allow reception of signals during transmission periods. This mode is known as full-duplex, and may require the transmitter and receiver to operate on different frequencies to minimize interference between the transmitted signal and the received signal. The transceiver 1010 may operate in a half- duplex mode, where the transceiver 1010 may transmit or receive signals in one direction at a time.

[0091] In accordance with some embodiments, the communications circuitry 1002 may be arranged to contend for a wireless medium and configure frames or packets for communicating over the wireless medium. The communications circuitry 1002 may be arranged to transmit and receive signals. The communications circuitry 1002 may also include circuitry for modulation/demodulation, upconversion/downconversion, filtering, amplification, etc. In some embodiments, the processing circuitry 1006 of the communication station 1000 may include one or more processors. In other embodiments, two or more antennas 1001 may be coupled to the communications circuitry 1002 arranged for sending and receiving signals. The memory 1008 may store information for configuring the processing circuitry 1006 to perform operations for configuring and transmitting message frames and performing the various operations described herein. The memory 1008 may include any type of memory, including non-transitory memory, for storing information in a form readable by a machine (e.g., a computer). For example, the memory 1008 may include a computer-readable storage device , read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices and other storage devices and media. [0092] In some embodiments, the communication station 1000 may be part of a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capability, a web tablet, a wireless telephone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), a wearable computer device, or another device that may receive and/or transmit information wirelessly.

[0093] In some embodiments, the communication station 1000 may include one or more antennas 1001. The antennas 1001 may include one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmission of RF signals. In some embodiments, instead of two or more antennas, a single antenna with multiple apertures may be used. In these embodiments, each aperture may be considered a separate antenna. In some multiple-input multiple-output (MIMO) embodiments, the antennas may be effectively separated for spatial diversity and the different channel characteristics that may result between each of the antennas and the antennas of a transmitting station.

[0094] In some embodiments, the communication station 1000 may include one or more of a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, speakers, and other mobile device elements. The display may be an LCD screen including a touch screen.

[0095] Although the communication station 1000 is illustrated as having several separate functional elements, two or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. For example, some elements may include one or more microprocessors, DSPs, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio-frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements of the communication station 1000 may refer to one or more processes operating on one or more processing elements. [0096] Certain embodiments may be implemented in one or a combination of hardware, firmware, and software. Other embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory memory mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage device may include read-only memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, and other storage devices and media. In some embodiments, the communication station 1000 may include one or more processors and may be configured with instructions stored on a computer-readable storage device memory.

[0097] FIG. 11 illustrates a block diagram of an example of a machine 1100 or system upon which any one or more of the techniques (e.g., methodologies) discussed herein may be performed. In other embodiments, the machine 1100 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine 1100 may operate in the capacity of a server machine, a client machine, or both in server-client network environments. In an example, the machine 1100 may act as a peer machine in peer-to-peer (P2P) (or other distributed) network environments. The machine 1100 may be a personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile telephone, wearable computer device, a web appliance, a network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine, such as a base station. Further, while only a single machine is illustrated, the term "machine" shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), or other computer cluster configurations.

[0098] Examples, as described herein, may include or may operate on logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations when operating. A module includes hardware. In an example, the hardware may be specifically configured to carry out a specific operation (e.g., hardwired). In another example, the hardware may include configurable execution units (e.g., transistors, circuits, etc.) and a computer readable medium containing instructions where the instructions configure the execution units to carry out a specific operation when in operation. The configuring may occur under the direction of the executions units or a loading mechanism. Accordingly, the execution units are communicatively coupled to the computer- readable medium when the device is operating. In this example, the execution units may be a member of more than one module. For example, under operation, the execution units may be configured by a first set of instructions to implement a first module at one point in time and reconfigured by a second set of instructions to implement a second module at a second point in time.

[0099] The machine (e.g., computer system) 1100 may include a hardware processor 1102 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 1104 and a static memory 1106, some or all of which may communicate with each other via an interlink (e.g., bus) 1108. The machine 1 100 may further include a power management device 1 132, a graphics display device 1 110, an alphanumeric input device 11 12 (e.g., a keyboard), and a user interface (UI) navigation device 1 114 (e.g., a mouse). In an example, the graphics display device 11 10, alphanumeric input device 1 112, and UI navigation device 11 14 may be a touch screen display. The machine 1 100 may additionally include a storage device (i.e., drive unit) 11 16, a signal generation device 1 118 (e.g., a speaker), a channel estimation field (CEF) device 1119, a network interface device/transceiver 1 120 coupled to antenna(s) 1 130, and one or more sensors 1 128, such as a global positioning system (GPS) sensor, compass, accelerometer, or other sensor. The machine 1100 may include an output controller 1134, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate with or control one or more peripheral devices (e.g., a printer, card reader, etc.)).

[0100] The storage device 1 116 may include a machine readable medium 1122 on which is stored one or more sets of data structures or instructions 1124 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 1 124 may also reside, completely or at least partially, within the main memory 1104, within the static memory 1106, or within the hardware processor 1 102 during execution thereof by the machine 1100. In an example, one or any combination of the hardware processor 1 102, the main memory 1104, the static memory 1106, or the storage device 11 16 may constitute machine-readable media. [0101] The CEF device 1 119 may carry out or perform any of the operations and processes described and shown above. For example, the CEF device 1 119 may be configured to cause to establish, by the device, one or more MIMO communication channels between the device and a plurality of devices; determine, by the device, an extended CEF for channel estimation in a time domain; and cause to send, by the device, to one or more of the plurality of devices, the extended CEF. In one embodiment, the MIMO communication channel includes a single carrier (SC) MIMO channel. In another embodiment, the CEF can use Golay complementary sequences. It is understood that the above are only a subset of what the CEF device 11 19 may be configured to perform and that other functions included throughout this disclosure may also be performed by the CEF device 1 1 19.

[0102] While the machine-readable medium 1122 is illustrated as a single medium, the term "machine-readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 1124.

[0103] Various embodiments may be implemented fully or partially in software and/or firmware. This software and/or firmware may take the form of instructions contained in or on a non-transitory computer-readable storage medium. Those instructions may then be read and executed by one or more processors to enable performance of the operations described herein. The instructions may be in any suitable form, such as but not limited to source code, compiled code, interpreted code, executable code, static code, dynamic code, and the like. Such a computer-readable medium may include any tangible non-transitory medium for storing information in a form readable by one or more computers, such as but not limited to read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; a flash memory, etc.

[0104] The term "machine-readable medium" may include any medium that is capable of storing, encoding, or carrying instructions for execution by the machine 1 100 and that cause the machine 1 100 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding, or carrying data structures used by or associated with such instructions. Non-limiting machine-readable medium examples may include solid-state memories and optical and magnetic media. In an example, a massed machine-readable medium includes a machine-readable medium with a plurality of particles having resting mass. Specific examples of massed machine-readable media may include non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Readonly Memory (EPROM), or Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD- ROM disks.

[0105] The instructions 1 124 may further be transmitted or received over a communications network 1126 using a transmission medium via the network interface device/transceiver 1 120 utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (UDP), hypertext transfer protocol (HTTP), etc.). Example communications networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone (POTS) networks, wireless data networks (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.1 1 family of standards known as Wi-Fi®, IEEE 802.16 family of standards known as WiMax®), IEEE 802.15.4 family of standards, and peer-to-peer (P2P) networks, among others. In an example, the network interface device/transceiver 1 120 may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network 1126. In an example, the network interface device/transceiver 1120 may include a plurality of antennas to wirelessly communicate using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MISO) techniques. The term "transmission medium" shall be taken to include any intangible medium that is capable of storing, encoding, or carrying instructions for execution by the machine 1100 and includes digital or analog communications signals or other intangible media to facilitate communication of such software. The operations and processes described and shown above may be carried out or performed in any suitable order as desired in various implementations. Additionally, in certain implementations, at least a portion of the operations may be carried out in parallel. Furthermore, in certain implementations, less than or more than the operations described may be performed.

[0106] Example 1 is a device, comprising: at least one memory that stores computer- executable instructions; and at least one processor of the one or more processors configured to access the at least one memory, wherein the at least one processor of the one or more processors is configured to execute the computer-executable instructions to: cause to establish, by the device, a multiple-input and multiple-output (MIMO) communication channel between the device and a plurality of devices; determine, by the device, an extended channel estimation field (CEF) for channel estimation of at least one of the MIMO communication channel in a time domain; and cause to send, by the device, to one or more of the plurality of devices, the extended CEF. In example 2, the device of example 1 can optionally include a MIMO communication channel comprising a single carrier (SC) MIMO channel. In example 3, the device of example 1 can optionally include the determination of the extended CEF based at least in part on a number of spatial streams of the MIMO communications channel. In example 4, the device of example 1 can optionally include the determination of the extended CEF based at least in part on a Golay complementary pair sequence set. In example 5, the device of example 1 can optionally include the determination of the extended CEF based at least in part on a Golay complementary pair sequence set. In example 6, the device of example 5 can optionally include the Golay complementary pair sequence set further comprising Golay sequences. In example 7, the device of example 1 can optionally include one or more sequences associated with the extended CEF determined with a predetermined sign pattern and repeated in time. In example 8, the device of example 7 can optionally include a predetermined sign pattern defined based on an orthogonal matrix. In example 9, the device of example 8 can optionally include an orthogonal matrix comprising a Hadamard matrix. In example 10, the device of example 1 can optionally include a transceiver configured to transmit and receive wireless signals and an antenna coupled to the transceiver.

[0107] Example 11 is a non-transitory computer-readable medium storing computer- executable instructions which, when executed by a processor, cause the processor to perform operations comprising: cause to establish, by the processor, multiple-input and multiple- output (MIMO) communication channels between a device and a second device; receive, by the processor, an extended channel estimation field (CEF) from the second device for channel estimation of at least one of the MIMO communication channels in a time domain; and cause to send, by the processor, to the second device, first information based at least in part on the extended CEF. In example 12, the medium of example 11 can optionally include a MIMO communication channel comprising a single carrier (SC) MIMO channel. In example 13, the medium of example 11 can optionally include the determination of the extended CEF based at least in part on a number of spatial streams of the MIMO communications channel. In example 14, the medium of example 11 can optionally include the determination of the extended CEF based at least in part on a channel bonding factor. In example 15, the medium of example 11 can optionally include the determination of the extended CEF based at least in part on a channel bonding factor. In example 16, the medium of example 15 can optionally include the Golay complementary pair sequence set further comprising Golay sequences. In example 17, the medium of example 11 can optionally include one or more sequences associated with the extended CEF determined with a predetermined sign partem and repeated in time.

[0108] Example 18 is a method, comprising: establishing multiple-input and multiple- output (MIMO) communication channels between a device and a second device; receiving an extended channel estimation field (CEF) from the second device for channel estimation of at least one of the MIMO communication channels in a time domain; and sending, to the second device, first information based at least in part on the extended CEF. In example 19, the method of example 18 can optionally include a MIMO communication channel comprising a single carrier (SC) MIMO channel. In example 20, the method of example 18 can optionally include the determination of the extended CEF based at least in part on a number of spatial streams of the MIMO communications channel. In example 21, the method of example 18 can optionally include the determination of the extended CEF based at least in part on a channel bonding factor. In example 22, the method of example 18 can optionally include the determination of the extended CEF based at least in part on a channel bonding factor. In example 23, the method of example 22 can optionally include the Golay complementary pair sequence set further comprising Golay sequences. In example 24, the method of example 18 can optionally include one or more sequences associated with the extended CEF determined with a predetermined sign partem and repeated in time.

[0109] Example 28 is a non-transitory computer-readable medium storing computer- executable instructions which, when executed by a processor, cause the processor to perform operations comprising at least one memory that stores computer-executable instructions; and at least one processor of the one or more processors configured to access the at least one memory, wherein the at least one processor of the one or more processors is configured to execute the computer-executable instructions to: causing to establish a multiple-input and multiple-output (MIMO) communication channel between the device and a plurality of devices; determining an extended channel estimation field (CEF) for channel estimation of at least one of the MIMO communication channel in a time domain; and causing to send to one or more of the plurality of devices, the extended CEF. In example 29, the method of example 28 can optionally include a MIMO communication channel comprising a single carrier (SC) MIMO channel. In example 30, the method of example 28 can optionally include the determination of the extended CEF based at least in part on a number of spatial streams of the MIMO communications channel. In example 31, the method of example 28 can optionally include the determination of the extended CEF based at least in part on a Golay complementary pair sequence set. In example 32, the method of example 28 can optionally include the determination of the extended CEF based at least in part on a Golay complementary pair sequence set. In example 33, the method of example 32 can optionally include the Golay complementary pair sequence set further comprising Golay sequences. In example 34, the method of example 28 can optionally include one or more sequences associated with the extended CEF determined with a predetermined sign pattern and repeated in time. In example 35, the method of example 34 can optionally include a predetermined sign pattern defined based on an orthogonal matrix. In example 36, the method of example 35 can optionally include an orthogonal matrix comprising a Hadamard matrix.

[0110] Example 37 is a method, comprising: causing to establish a multiple-input and multiple-output (MIMO) communication channel between the device and a plurality of devices; determining an extended channel estimation field (CEF) for channel estimation of at least one of the MIMO communication channel in a time domain; and causing to send to one or more of the plurality of devices, the extended CEF. In example 38, the method of example 37 can optionally include a MIMO communication channel comprising a single carrier (SC) MIMO channel. In example 39, the method of example 37 can optionally include the determination of the extended CEF based at least in part on a number of spatial streams of the MIMO communications channel. In example 40, the method of example 37 can optionally include the determination of the extended CEF based at least in part on a Golay complementary pair sequence set. In example 41, the method of example 37 can optionally include the determination of the extended CEF based at least in part on a Golay complementary pair sequence set. In example 42, the method of example 41 can optionally include the Golay complementary pair sequence set further comprising Golay sequences. In example 43, the method of example 37 can optionally include one or more sequences associated with the extended CEF determined with a predetermined sign pattern and repeated in time. In example 44, the method of example 43 can optionally include a predetermined sign pattern defined based on an orthogonal matrix. In example 45, the method of example 44 can optionally include an orthogonal matrix comprising a Hadamard matrix.

[0111] Example 49 is an apparatus comprising means for: causing to establish a multiple- input and multiple-output (MIMO) communication channel between the device and a plurality of devices; determining an extended channel estimation field (CEF) for channel estimation of at least one of the MIMO communication channel in a time domain; and causing to send to one or more of the plurality of devices, the extended CEF. In example 50, the apparatus of example 49 can optionally include a MIMO communication channel comprising a single carrier (SC) MIMO channel. In example 51, the apparatus of example 49 can optionally include the determination of the extended CEF based at least in part on a number of spatial streams of the MIMO communications channel. In example 52, the apparatus of example 49 can optionally include the determination of the extended CEF based at least in part on a Golay complementary pair sequence set. In example 53, the apparatus of example 49 can optionally include the determination of the extended CEF based at least in part on a Golay complementary pair sequence set. In example 54, the apparatus of example 53 can optionally include the Golay complementary pair sequence set further comprising Golay sequences. In example 55, the apparatus of example 49 can optionally include one or more sequences associated with the extended CEF determined with a predetermined sign partem and repeated in time. In example 56, the apparatus of example 55 can optionally include a predetermined sign pattern defined based on an orthogonal matrix. In example 57, the apparatus of example 56 can optionally include an orthogonal matrix comprising a Hadamard matrix.

[0112] Example 58 is a device, comprising: at least one memory that stores computer- executable instructions; and at least one processor of the one or more processors configured to access the at least one memory, wherein the at least one processor of the one or more processors is configured to execute the computer-executable instructions to: establish multiple-input and multiple-output (MIMO) communication channels between a device and a second device; receive an extended channel estimation field (CEF) for channel estimation of at least one of the MIMO communication channels in a time domain; determine first information based at least in part on the received extended CEF; and send, to the second device, the first information. In example 59, the device of example 58 can optionally include a MIMO communication channel comprising a single carrier (SC) MIMO channel. In example 60, the device of example 58 can optionally include the determination of the extended CEF based at least in part on a number of spatial streams of the MIMO communications channel. In example 61, the device of example 58 can optionally include the determination of the extended CEF based at least in part on a channel bonding factor. In example 62, the device of example 58 can optionally include the determination of the extended CEF based at least in part on a channel bonding factor. In example 63, the device of example 62 can optionally include the Golay complementary pair sequence set further comprising Golay sequences. In example 64, the device of example 58 can optionally include one or more sequences associated with the extended CEF determined with a predetermined sign pattern and repeated in time.

[0113] Example 65 is an apparatus, comprising means for: establishing multiple-input and multiple-output (MIMO) communication channels between a device and a second device; receiving an extended channel estimation field (CEF) from the second device for channel estimation of at least one of the MIMO communication channels in a time domain; and sending, to the second device, first information based at least in part on the extended CEF. In example 66, the apparatus of example 65 can optionally include a MIMO communication channel comprising a single carrier (SC) MIMO channel. In example 67, the apparatus of example 65 can optionally include the determination of the extended CEF based at least in part on a number of spatial streams of the MIMO communications channel. In example 68, the apparatus of example 65 can optionally include the determination of the extended CEF based at least in part on a channel bonding factor. In example 69, the apparatus of example 65 can optionally include the determination of the extended CEF based at least in part on a channel bonding factor. In example 70, the apparatus of example 69 can optionally include the Golay complementary pair sequence set further comprising Golay sequences. In example 71, the apparatus of example 65 can optionally include one or more sequences associated with the extended CEF determined with a predetermined sign pattern and repeated in time.

[0114] In one embodiment, the CE's can be composed of GU ₄ N and GV' ₄ N sequences (504 and 506, respectively) and -Gb N sequence 508 at the end of the frame, where the index i can define spatial stream number and sub-index 4N or N can define the corresponding sequence length. In one embodiment, the defined CE'i may have an additional -Ga N sequence 502 as a prefix, which can serve to distinguish the field from the legacy subfield. In one embodiment, the introduction of this extra -Ga _N sequence 502 can permit a more accurate channel estimation in the time domain and/or frequency domain.

[0115] In one embodiment, as shown in FIG. 5B element 501, the CEF can include a Gu 1024 field, a Gv 1024 field, and a -Gb \ ₅₆ field; the CEF can have a duration having a value approximately equal to 2304*Tc/2.

[0116] In one embodiment, as shown in FIG. 5C element 503, the CEF can include a Gu 2048 field, a Gv 2048 field, and a -Gb\ _u field; the CEF can have a duration having a value approximately equal to 4608*Tc/4.

[0117] In one embodiment, as shown in FIG. 5D element 507, the CEF can include a Gu ₁ 1536 field, a Gv ¹ 15 fi3e6ld, and a -Gb ¹ 384 field; the CEF can have a duration having a value approximately equal to 3456*Tc/3.

[0118] In one embodiment, as shown in FIG. 5E element 509, the CEF can include a Gu ^X 512 field, a Gv ¹ su field, and a -Gb ^X 128 field for ISTS = 1; the CEF can include a Gu ² 512 field, a Gv ² 512 field, and a -Gb ² 128 field for ISTS = 2; the CEF can have a duration having a value approximately equal to 1152*Tc.

[0119] In one embodiment, as shown in FIG. 5F element 511, the CEF can include a Gu ¹ 1024 field, a Gv ¹ ^ field, and a -Gb ¹ 2se field for ISTS = 1; the CEF can include a Gu ² 1024 field, a Gv ² 1024 field, and a -Gb ² 256 field for ISTS = 2; the CEF can have a duration having a value approximately equal to 2304*(Tc/2).

[0120] In one embodiment, as shown in FIG. 5G element 513, the CEF can include a Gu ₁ 1536 field, a Gv^se field, and a -Gb ^X 384 field for ISTS = 1; the CEF can include a Gu ² 1536 field, a Gv ² 1536 field, and a -Gb ² 384 field for ISTS = 2; the CEF can have a duration having a value approximately equal to 3456*(Tc/3).

[0121] In one embodiment, as shown in FIG. 5H element 515, the CEF can include a Gu^im field, a GV^IMS field, and a -Gb ^ ₁₂ field for ISTS = 1; the CEF can include a Gu ² 2048 field, a Gv ² 2048 field, and a -Gb ² su field for ISTS = 2; the CEF can have a duration having a value approximately equal to 4608*(Tc/4).

[0122] In one embodiment, as shown in FIG. 51 element 517, the CEF can include a Gu ^X 512 field, a Gv ¹ su field, a -Gb ¹ ₁ 28 field, a -Ga ¹ 128 field, a Gu ₁ field, a Gv ^ ₁₂ field, and a -Gb ¹ 128 for ISTS = 1 ; the CEF can include a Gu ² 512 field, a Gv ² 512 field, a -Gb ² 128 field, a -Ga ² 128 field, a Gu ² 512 field, a Gv ² su field, and a -Gb ² 128 for ISTS = 2; the CEF can include a Gu ³ 512 field, a Gv ³ ₅ i2 field, a -Gb ³ i ₂ 8 field, a Ga ³ i ₂ 8 field, a -Gu ³ ₅ i2 field, a -Gv ³ ₅ i2 field, and a Gb ³ 128 for ISTS = 3; the CEF can include a Gu ⁴ 512 field, a Gv ⁴ 512 field, a -Gb ⁴ 128 field, a Ga ⁴ 128 field, a -Gu ⁴ 512 field, a -Gv ⁴ ¾i2 field, and a Gb ⁴ 128 for ISTS = 4; the CEF can have a duration having a value approximately equal to 2432*Tc.

[0123] In one embodiment, as shown in FIG. 5J element 519, the CEF can include a Gu ¹ 1024 field, a Gv ¹ ^ field, a -Gb ¹ 2se field, a -Ga ¹ ^ field, a Gu ¹ 1024 field, a Gv ^X 1024 field, and a -Gb ¹ ^ for ISTS = 1 ; the CEF can include a Gu ² 1024 field, a Gv ² 1024 field, a -Gb ² 2se field, a -Ga ² 256 field, a Gu ² 1024 field, a Gv ² 1024 field, and a -Gb ² 256 for ISTS = 2; the CEF can include a Gu ³ 1024 field, a Gv ³ 1024 field, a -Gb ³ 256 field, a Ga ³ 256 field, a -Gu ³ 1024 field, a -Gv ³ 1024 field, and a Gb ³ 256 for ISTS = 3; the CEF can include a Gu ⁴ 1024 field, a Gv ⁴ 1024 field, a - Gb ⁴ 256 field, a Ga ⁴ 256 field, a -Gu ⁴ 1024 field, a -Gv ⁴ 1024 field, and a Gb ⁴ 256 for ISTS = 4; the CEF can have a duration having a value approximately equal to 4864*(Tc/2).

[0124] In one embodiment, as shown in FIG. 5K element 521, the CEF can include a Gu ₁ 1536 field, a Gv ¹ ΐ536 field, a -Gb ^84 field, a -Ga^ field, a Gu ¹ 1536 field, a Gv ¹ 1536 field, and a -Gb ^X 384 for ISTS = 1; the CEF can include a Gu ² 1536 field, a Gv ² 1536field, a -Gb ² 384 field, a -Ga ² 384 field, a Gu ² 1536 field, a Gv ² 1536 field, and a -Gb ² 384 for ISTS = 2; the CEF can include a Gu ³ 1536 field, a Gv ³ 1536 field, a -Gb ³ 384 field, a Ga ³ 384 field, a -Gu ³ 1536 field, a -Gv ³ 1536 field, and a Gb ³ 384 for ISTS = 3; the CEF can include a Gu ⁴ 1536 field, a Gv ⁴ 1536 field, a - Gb ⁴ 384 field, a Ga ⁴ 384 field, a -Gu ⁴ 1536 field, a -Gv ⁴ 1536 field, and a Gb ⁴ 384 for ISTS = 4; the CEF can have a duration having a value approximately equal to 6912*(Tc/3).

[0125] In one embodiment, as shown in FIG. 5L element 523, the CEF can include a Gu^im field, a GV^IMS field, a -Gb ^12 field, a -Ga ¹ su field, a GU^IMS field, a Gv ^X 2048 field, and a -Gb^ for ISTS = 1 ; the CEF can include a Gu ² 2048 field, a Gv ² 2048 field, a -Gb ² su field, a -Ga ² 512 field, a Gu ² 2048 field, a Gv ² 2048 field, and a -Gb ² 512 for ISTS = 2; the CEF can include a Gu ³ 2048 field, a Gv ³ 2048 field, a -Gb ³ ¾i2 field, a Ga ³ 512 field, a -Gu ³ 2048 field, a -Gv ³ 2048 field, and a Gb ³ 512 for ISTS = 3; the CEF can include a Gu ⁴ 2048 field, a Gv ⁴ 2048 field, a - Gb ⁴ 512 field, a Ga ⁴ 512 field, a -Gu ⁴ 2048 field, a -Gv %48 field, and a Gb ⁴ 512 for ISTS = 4; the CEF can have a duration having a value approximately equal to 9728*(Tc/4).

[0126] In one embodiment, as shown in FIG. 5M element 525, the CEF can include a Gu ^X 512 field, a Gv^ field, a -Gb^s field, a -Ga ¹ 128 field, a Gu^o field, a Gv^ field, a - Gb ¹ 128 , a -Ga ¹ 128 field, a Gu^o field, a Gv^ field, a -Gb^s field, a -Ga^s field, a Gu^o field, a Gv^o field, and a -Gb ¹ 128 for ISTS = 1 ; the CEF can include a Gu ² 512 field, a Gv ² 512 field, a -Gb 128 field, a -Ga 128 field, a Gu 512 field, a Gv 512 field, a -Gb 128 , a -Ga 128 2 2 2 2 2 2 field, a Gu so field, a Gv 512 field, a -Gb 128 field, a -Ga 128 field, a Gu 512 field, a Gv 512 field, and a -Gb ² 128 for ISTS = 2; the CEF can include a Gu ³ 512 field, a Gv ³ 512 field, a -Gb ³ i28 field, a -Ga ³ 128 field, a -Gu ³ ₅ i2 field, a -Gv ³ ₅ i2 field, a -Gb ³ i ₂ 8 , a -Ga ³ i ₂ 8 field, a Gu ³ ₅ i2 field, a Gv ³ 512 field, a -Gb ³ 128 field, a Ga ³ 128 field, a -Gu ³ 512 field, a -Gv ³ 512 field, and a Gb ³ 128 for ISTS = 3; the CEF can include a Gu ⁴ 512 field, a Gv ⁴ 512 field, a -Gb ⁴ 128 field, a - Ga ⁴ 128 field, a -Gu ⁴ 512 field, a -Gv ⁴ 512 field, a -Gb ⁴ 128 , a -Ga ⁴ 128 field, a Gu ⁴ 512 field, a Gv ⁴ 512 field, a -Gb ⁴ 128 field, a Ga ⁴ 128 field, a -Gu ⁴ 512 field, a -Gv ⁴ 512 field, and a Gb ⁴ 128 for ISTS = 4; the CEF can include a Gu ⁵ 512 field, a Gv ⁵ 512 field, a -Gb ⁵ 128 field, a -Ga ⁵ 128 field, a Gu ⁵ 512 field, a Gv ⁵ 512 field, a -Gb ⁵ 128 , a Ga ⁵ 128 field, a -Gu ⁵ 512 field, a -Gv ⁵ 512field, a Gb ⁵ i28 field, a Ga ⁵ i2 ₈ field, a -Gu ⁵ 512 field, a -Gv ⁵ 512 field, and a Gb ⁵ i2 ₈ for ISTS = 5; the CEF can include a Gu ⁶ 512 field, a Gv ⁶ 512 field, a -Gb ⁶ 128 field, a -Ga ⁶ 128 field, a Gu ⁶ 512 field, a Gv ⁶ 512 field, a -Gb ⁶ 128 , a Ga ⁶ 128 field, a -Gu ⁶ 512 field, a -Gv ⁶ 512 field, a Gb ⁶ 128 field, a Ga ⁶ 128 field, a -Gu ⁶ 512 field, a -Gv ⁶ 512 field, and a Gb ⁶ 128 for ISTS = 6; the CEF can include a Gu ⁷ 512 field, a

7 7 7 7 7 7 7

Gv 512 field, a -Gb 128 field, a Ga 128 field, a -Gu 512 field, a -Gv 512 field, a Gb 128 , a Ga 128

7 7 7 7 7 7 field, a -Gu 512 field, a -Gv 512 field, a Gb 128 field, a -Ga 128 field, a Gu 512 field, a Gv 512 field, and a -Gb ⁷ 128 for ISTS = 7; the CEF can include a Gu ⁸ 512 field, a Gv ⁸ 512 field, a -Gb ⁸ i28 field, a Ga ⁸ 128 field, a -Gu ⁸ ₅ i ₂ field, a -Gv ⁸ ₅ i ₂ field, a Gb ⁸ i ₂₈ , a Ga ⁸ i ₂₈ field, a -Gu ⁸ ₅ i ₂ field, a -Gv ⁸ 512 field, a Gb ⁸ 128 field, a -Ga ⁸ 128 field, a Gu ⁸ 512 field, a Gv ⁸ 512 field, and a -Gb ⁸ 128 for ISTS = 8; the CEF can have a duration having a value approximately equal to 4992*Tc.

[0127] In one embodiment, as shown in FIG. 5N element 527, the CEF can include a Gu ¹ ^ field, a Gv ¹ ^ field, a -Gb^se field, a -Ga^se field, a Gu ¹ ^ field, a Gv ¹ ^ field, a -Gb^e , a -Ga^se field, a Gu ¹ 1024 field, a Gv ¹ ^ field, a -Gb^se field, a -Ga ¹ 2se field, a Gu ¹ 1024 field, a Gv ¹ ^ field, and a -Gb^se for ISTS = 1 ; the CEF can include a Gu ² 1024 field,

2 2 2 2 2 2 a Gv 1024 field, a -Gb 256 field, a -Ga 256 field, a Gu 1024 field, a Gv 1024 field, a -Gb 256 , a - Ga 256 field, a Gu 1024 field, a Gv 1024 field, a -Gb 256 field, a -Ga 256 field, a Gu 1024 field, a Gv ² 1024 field, and a -Gb ² 256 for ISTS = 2; the CEF can include a Gu ³ 1024 field, a Gv ³ 1024 field, a -Gb ³ 256 field, a -Ga ³ 256 field, a -Gu ³ 1024 field, a -Gv ³ 1024 field, a -Gb ³ 256 , a -Ga ³ 256 field, a Gu ³ 1024 field, a Gv ³ 1024 field, a -Gb ³ 256 field, a Ga ³ 256 field, a -Gu ³ 1024 field, a -Gv ³ 1024 field, and a Gb ³ 256 for ISTS = 3; the CEF can include a Gu ⁴ 1024 field, a Gv ⁴ 1024 field, a -Gb ⁴ 256 field, a -Ga ⁴ 256 field, a -Gu ⁴ 1024 field, a -Gv ⁴ 1024 field, a -Gb ⁴ 256 , a -Ga ⁴ 256 field, a Gu ⁴ 1024 field, a Gv ⁴ 1024 field, a -Gb ⁴ 256 field, a Ga ⁴ 256 field, a -Gu ⁴ 1024 field, a -Gv ⁴ 1024 field, and a Gb ⁴ 256 for ISTS = 4; the CEF can include a Gu ⁵ 1024 field, a Gv ⁵ 1024 field, a -Gb ⁵ 256 field, a -Ga ⁵ 256 field, a Gu 1024 field, a Gv 1024 field, a -Gb 256 , a Ga 256 field, a -Gu 1024 field, a -Gv 1024 field, a Gb ⁵ 256 field, a Ga ⁵ 256 field, a -Gu ⁵ 1024 field, a -Gv ⁵ 1024 field, and a Gb ⁵ 256 for ISTS = 5; the CEF can include a Gu ⁶ 1024 field, a Gv ⁶ 1024 field, a -Gb ⁶ 256 field, a -Ga ⁶ 256 field, a Gu ⁶ 1024 field, a Gv ⁶ 1024 field, a -Gb ⁶ 256 , a Ga ⁶ 256 field, a -Gu ⁶ 1024 field, a -Gv ⁶ 1024 field, a Gb ⁶ 256 field, a Ga ⁶ 256 field, a -Gu ⁶ 1024 field, a -Gv ⁶ 1024 field, and a Gb ⁶ 256 for ISTS = 6; the

CEF can include a Gu ₇ 1024 field, a Gv ⁷ 1024 field, a - Gb ⁷ 256 field, a Ga ⁷ 256 field, a - Gu ₇ 1024 field, a - Gv ⁷ 1024 field, a Gb ⁷ 256 , a Ga ⁷ 256 field, a - Gu ₇ 1024 field, a - Gv ⁷ 1024 field, a Gb ⁷ 256 field, a -Ga ⁷ 256 field, a Gu ⁷ 1024 field, a Gv ⁷ 1024 field, and a -Gb ⁷ 256 for ISTS = 7; the CEF can

8 8 8 8 8 include a Gu 1024 field, a Gv 1024 field, a -Gb 256 field, a Ga 256 field, a -Gu 1024 field, a - Gv ⁸ 1024 field, a Gb ⁸ ₂ 56 , a Ga ⁸ ₂ 56 field, a -Gu ⁸ 1024 field, a -Gv ⁸ 1024 field, a Gb ⁸ ₂ 56 field, a - Ga ⁸ 256 field, a Gu ⁸ 1024 field, a Gv ⁸ 1024 field, and a -Gb ⁸ 256 for ISTS = 8; the CEF can have a duration having a value approximately equal to 9984*(Tc/2).

[0128] In one embodiment, as shown in FIG. 50 element 529, the CEF can include a Gu ₁ 1536 field, a Gv ¹ 1536 field, a -Gb ¹ 384 field, a -Ga ¹ 384 field, a Gu ₁ 1536 field, a Gv ¹ 1536 field, a -Gb ¹ 384 , a -Ga ¹ 384 field, a Gu ₁ 1536 field, a Gv ¹ 1536 field, a -Gb^ field, a -Ga ¹ 384 field, a Gu ₁ 1536 field, a Gv ¹ 1536 field, and a -Gb ¹ 384 for ISTS = 1 ; the CEF can include a Gu ² 1536 field, a Gv 1536 field, a -Gb 384 field, a -Ga 384 field, a Gu 1536 field, a Gv 1536 field, a -Gb 384 , a - 'J

Ga ² 384 field, a Gu ² 1536 field, a Gv ² 1536 field, a - Gb ² 384 field, a -Ga ² 384 field, a Gu ² 1536 field, a Gv ² 1536 field, and a -Gb ² 384 for ISTS = 2; the CEF can include a Gu ³ 1536 field, a Gv ³ 1536 field, a -Gb ³ 384 field, a -Ga ³ 384 field, a -Gu ³ 1536 field, a -Gv ³ 1536 field, a -Gb ³ 384 , a -Ga ³ 384 field, a Gu ³ 1536 field, a Gv ³ 1536 field, a -Gb ³ 384 field, a Ga ³ 384 field, a -Gu ³ 1536 field, a -Gv ³ 1536 field, and a Gb ³ 384 for ISTS = 3; the CEF can include a Gu ⁴ 1536 field, a Gv ⁴ 1536 field, a -Gb ⁴ 384 field, a -Ga ⁴ 384 field, a -Gu ⁴ 1536 field, a -Gv ⁴ 1536 field, a -Gb ⁴ 384 , a -Ga ⁴ 384 field, a Gu ⁴ 1536 field, a Gv ⁴ 1536 field, a -Gb ⁴ 384 field, a Ga ⁴ 384 field, a -Gu ⁴ 1536 field, a -Gv ⁴ 1536 field, and a Gb ⁴ 384 for ISTS = 4; the CEF can include a Gu ⁵ 1536 field, a Gv ⁵ 1536 field, a -Gb ⁵ 384 field, a -Ga ⁵ 384 field, a Gu ⁵ 1536 field, a Gv ⁵ 1536 field, a -Gb ⁵ 384 , a Ga ⁵ 384 field, a -Gu ⁵ 1536 field, a -Gv ⁵ 1536 field, a Gb ⁵ 384 field, a Ga ⁵ 384 field, a -Gu ⁵ 1536 field, a -Gv ⁵ 1536 field, and a Gb ⁵ 384 for ISTS = 5; the CEF can include a Gu ⁶ 1536 field, a Gv ⁶ 1536 field, a -Gb ⁶ 384 field, a -Ga ⁶ 384 field, a Gu ⁶ 1536 field, a Gv ⁶ 1536 field, a -Gb ⁶ 384 , a Ga ⁶ 384 field, a -Gu ⁶ 1536 field, a -Gv ⁶ 1536 field, a Gb ⁶ 384 field, a Ga ⁶ 384 field, a -Gu ⁶ 1536 field, a -Gv ⁶ 1536 field, and a Gb ⁶ 384 for ISTS = 6; the

CEF can include a Gu ₇ 1536 field, a Gv 1536 field, a -Gb 384 field, a Ga 384 field, a -Gu 1536 field, a - Gv ⁷ 1536 field, a Gb ⁷ 384 , a Ga ⁷ 384 field, a - Gu ₇ 1536 field, a - Gv ⁷ 1536 field, a Gb ⁷ 384 field, a -Ga ⁷ 384 field, a Gu ⁷ 1536 field, a Gv ⁷ 1536 field, and a -Gb ⁷ 3S4 for ISTS = 7; the CEF can include a Gu ⁸ 1536 field, a Gv ⁸ 1536 field, a -Gb ⁸ 384 field, a Ga ⁸ 384 field, a -Gu ⁸ 1536 field, a - Gv ⁸ i536 field, a Gb ⁸ 384 , a Ga ⁸ 384 field, a -Gu ⁸ 1536 field, a -Gv ⁸ 1536 field, a Gb ⁸ 384 field, a - Ga ⁸ 384 field, a Gu ⁸ 1536 field, a Gv ⁸ 1536 field, and a -Gb ⁸ 384 for i _ST s = 8; the CEF can have a duration having a value approximately equal to 14976*(Tc/3).

[0129] In one embodiment, as shown in FIG. SP element 531, the CEF can include a Gu ¹ 2048 field, a Gv ¹ 2048 field, a -Gb^u field, a -G& ^l sn field, a Gu ¹ 2048 field, a Gv ¹ 2048 field, a -Gb ¹ 512 , a -Ga ¹ 512 field, a Gu ¹ 2048 field, a Gv ¹ 2048 field, a -Gb ¹ 512 field, a -Ga ¹ 512 field, a Gu ¹ 2048 field, a Gv ¹ 2048 field, and a -Gb ¹ 512 for ISTS = 1; the CEF can include a Gu ² 2048 field, a Gv ² 2048 field, a -Gb ² 512 field, a -Ga ² 512 field, a Gu ² 2048 field, a Gv ¹ 2048 field, a -Gb ² 512 , a - Ga ² 512 field, a Gu ² 2o*8 field, a Gv ¹ 2048 field, a -Gb ² 512 field, a -Ga ² 512 field, a Gu ² 2048 field, a Gv ² 2o*8 field, and a -Gb ² 512 for ISTS = 2; the CEF can include a Gu ³ 2048 field, a Gv ³ 2048 field, a -Gb ³ 512 field, a -Ga ³ 512 field, a -Gu ³ 2048 field, a -Gv ³ 2048 field, a -Gb ³ 512 , a -Ga ³ 512 field, a Gu ³ 2o*8 field, a Gv ³ 2048 field, a -Gb ³ 512 field, a Ga ³ 512 field, a -Gu ³ 2048 field, a -Gv ³ 2048 field, and a Gb ³ 512 for ISTS = 3; the CEF can include a Gu ⁴ 2048 field, a Gv ⁴ 2048 field, a -Gb ⁴ 512 field, a -Ga ⁴ 512 field, a -Gu ⁴ 2048 field, a -Gv ⁴ 2o*e field, a -Gb ⁴ 512 , a -Ga ⁴ 512 field, a Gu ⁴ 2048 field, a Gv ⁴ 2o*8 field, a -Gb ⁴ 512 field, a Ga ⁴ 512 field, a -Gu ⁴ 2048 field, a -Gv ⁴ 2048 field, and a Gb ⁴ S12 for ISTS = 4; the CEF can include a Gu ⁵ 2048 field, a Gv ⁵ 2o*8 field, a -Gb ⁵ 512 field, a -Ga ⁵ 512 field, a Gu ⁵ 2048 field, a Gv ⁵ 2048 field, a -Gb'sn , a Ga'sn field, a -Gu ⁵ 2048 field, a -Gv ⁵ 2048 field, a Gb ⁵ 512 field, a Ga'sn field, a -Gu ⁵ 2048 field, a -Gv ⁵ 2048 field, and a Gb'sn for ISTS = 5; the CEF can include a Gu ⁶ 2048 field, a Gv ⁶ 2048 field, a -Gb ⁶ 512 field, a -Ga ⁶ 512 field, a Gu ⁶ 2o*8 field, a Gv ⁶ 2048 field, a -Gb ⁶ 512 , a Ga ⁶ 512 field, a -Gu ⁶ 2048 field, a -Gv ⁶ 2048 field, a Gb ⁶ 512 field, a Ga ⁶ ₅ i ₂ field, a -Gu ⁶ 2048 field, a -Gv ⁶ 2048 field, and a Gb ⁶ 512 for ISTS ⁼ 6; the CEF can include a Gu ⁷ 2048 field, a Gv ⁷ 2048 field, a -Gb ⁷ 512 field, a Ga ⁷ 512 field, a -Gu ⁷ 2048 field, a -Gv ⁷ 2048 field, a Gb ⁷ 512 , a Ga ⁷ 512 field, a -Gu ⁷ 2048 field, a -Gv ⁷ 2048 field, a Gb ⁷ 512 field, a -Ga ⁷ 512 field, a Gu ⁷ 2048 field, a Gv ⁷ 2048 field, and a -Gb ⁷ 512 for ISTS = 7; the CEF can include a Gu ⁸ 2048 field, a Gv ⁸ 2048 field, a -Gb ⁸ 512 field, a Ga ⁸ 512 field, a -Gu ⁸ 2048 field, a - Gv ⁸ 2048 field, a Gb ⁸ 512 , a Ga ⁸ 512 field, a -Gu ⁸ 2048 field, a -Gv ⁸ 2048 field, a Gb ⁸ 512 field, a - Ga ⁸ 512 field, a Gu ⁸ 2048 field, a Gv ⁸ 2048 field, and a -Gb ⁸ 512 for ISTS = 8; the CEF can have a duration having a value approximately equal to 19968*(Tc/4).

[0130] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be

39 construed as preferred or advantageous over other embodiments. The terms "computing device", "user device", "communication station", "station", "handheld device", "mobile device", "wireless device" and "user equipment" (UE) as used herein refers to a wireless communication device such as a cellular telephone, smartphone, tablet, netbook, wireless terminal, laptop computer, a femtocell, High Data Rate (HDR) subscriber station, access point, printer, point of sale device, access terminal, or other personal communication system (PCS) device. The device may be either mobile or stationary.

[0131] As used within this document, the term "communicate" is intended to include transmitting, or receiving, or both transmitting and receiving. This may be particularly useful in claims when describing the organization of data that is being transmitted by one device and received by another, but only the functionality of one of those devices is required to infringe the claim. Similarly, the bidirectional exchange of data between two devices (both devices transmit and receive during the exchange) may be described as 'communicating', when only the functionality of one of those devices is being claimed. The term "communicating" as used herein with respect to a wireless communication signal includes transmitting the wireless communication signal and/or receiving the wireless communication signal. For example, a wireless communication unit, which is capable of communicating a wireless communication signal, may include a wireless transmitter to transmit the wireless communication signal to at least one other wireless communication unit, and/or a wireless communication receiver to receive the wireless communication signal from at least one other wireless communication unit.

[0132] The term "access point" (AP) as used herein may be a fixed station. An access point may also be referred to as an access node, a base station, or some other similar terminology known in the art. An access terminal may also be called a mobile station, user equipment (UE), a wireless communication device, or some other similar terminology known in the art. Embodiments disclosed herein generally pertain to wireless networks. Some embodiments can relate to wireless networks that operate in accordance with one of the IEEE 802.11 standards.

[0133] Some embodiments may be used in conjunction with various devices and systems, for example, a Personal Computer (PC), a desktop computer, a mobile computer, a laptop computer, a notebook computer, a tablet computer, a server computer, a handheld computer, a handheld device, a Personal Digital Assistant (PDA) device, a handheld PDA device, an on- board device, an off-board device, a hybrid device, a vehicular device, a non-vehicular device, a mobile or portable device, a consumer device, a non-mobile or non-portable device, a wireless communication station, a wireless communication device, a wireless Access Point (AP), a wired or wireless router, a wired or wireless modem, a video device, an audio device, an audio-video (A/V) device, a wired or wireless network, a wireless area network, a Wireless Video Area Network (WVAN), a Local Area Network (LAN), a Wireless LAN (WLAN), a Personal Area Network (PAN), a Wireless PAN (WPAN), and the like.

[0134] Some embodiments may be used in conjunction with one way and/or two-way radio communication systems, cellular radio-telephone communication systems, a mobile phone, a cellular telephone, a wireless telephone, a Personal Communication Systems (PCS) device, a PDA device which incorporates a wireless communication device, a mobile or portable Global Positioning System (GPS) device, a device which incorporates a GPS receiver or transceiver or chip, a device which incorporates an RFID element or chip, a Multiple- Input Multiple- Output (MIMO) transceiver or device, a Single- Input Multiple- Output (SIMO) transceiver or device, a Multiple- Input Single- Output (MISO) transceiver or device, a device having one or more internal antennas and/or external antennas, Digital Video Broadcast (DVB) devices or systems, multi-standard radio devices or systems, a wired or wireless handheld device, e.g., a Smartphone, a Wireless Application Protocol (WAP) device, or the like.

[0135] Some embodiments may be used in conjunction with one or more types of wireless communication signals and/or systems following one or more wireless communication protocols, for example, Radio Frequency (RF), Infra Red (IR), Frequency- Division Multiplexing (FDM), Orthogonal FDM (OFDM), Time-Division Multiplexing (TDM), Time-Division Multiple Access (TDMA), Extended TDMA (E-TDMA), General Packet Radio Service (GPRS), extended GPRS, Code-Division Multiple Access (CDMA), Wideband CDMA (WCDMA), CDMA 2000, single-carrier CDMA, multi-carrier CDMA, Multi-Carrier Modulation (MDM), Discrete Multi-Tone (DMT), Bluetooth®, Global Positioning System (GPS), Wi-Fi, Wi-Max, ZigBeeTM, Ultra-Wideband (UWB), Global System for Mobile communication (GSM), 2G, 2.5G, 3G, 3.5G, 4G, Fifth Generation (5G) mobile networks, 3GPP, Long Term Evolution (LTE), LTE advanced, Enhanced Data rates for GSM Evolution (EDGE), or the like. Other embodiments may be used in various other devices, systems, and/or networks. [0136] Certain aspects of the disclosure are described above with reference to block and flow diagrams of systems, methods, apparatuses, and/or computer program products according to various implementations. It will be understood that one or more blocks of the block diagrams and flow diagrams, and combinations of blocks in the block diagrams and the flow diagrams, respectively, can be implemented by computer-executable program instructions. Likewise, some blocks of the block diagrams and flow diagrams may not necessarily need to be performed in the order presented, or may not necessarily need to be performed at all, according to some implementations.

[0137] These computer-executable program instructions may be loaded onto a special- purpose computer or other particular machine, a processor, or other programmable data processing apparatus to produce a particular machine, such that the instructions that execute on the computer, processor, or other programmable data processing apparatus create means for implementing one or more functions specified in the flow diagram block or blocks. These computer program instructions may also be stored in a computer-readable storage media or memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable storage media produce an article of manufacture including instruction means that implement one or more functions specified in the flow diagram block or blocks. As an example, certain implementations may provide for a computer program product, comprising a computer- readable storage medium having a computer-readable program code or program instructions implemented therein, said computer-readable program code adapted to be executed to implement one or more functions specified in the flow diagram block or blocks. The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational elements or steps to be performed on the computer or other programmable apparatus to produce a computer-implemented process such that the instructions that execute on the computer or other programmable apparatus provide elements or steps for implementing the functions specified in the flow diagram block or blocks.

[0138] Accordingly, blocks of the block diagrams and flow diagrams support combinations of means for performing the specified functions, combinations of elements or steps for performing the specified functions and program instruction means for performing the specified functions. It will also be understood that each block of the block diagrams and flow diagrams, and combinations of blocks in the block diagrams and flow diagrams, can be implemented by special-purpose, hardware-based computer systems that perform the specified functions, elements or steps, or combinations of special-purpose hardware and computer instructions.

[0139] Conditional language, such as, among others, "can," "could," "might," or "may," unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain implementations could include, while other implementations do not include, certain features, elements, and/or operations. Thus, such conditional language is not generally intended to imply that features, elements, and/or operations are in any way required for one or more implementations or that one or more implementations necessarily include logic for deciding, with or without user input or prompting, whether these features, elements, and/or operations are included or are to be performed in any particular implementation.

[0140] Many modifications and other implementations of the disclosure set forth herein will be apparent having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the disclosure is not to be limited to the specific implementations disclosed and that modifications and other implementations are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.