Cross Reference to Related Applications

The present application claims priority to U.S. Provisional Patent Application No. 62/235,345, filed, September 30, 2015 entitled "HETEROGENEOUS BEAMFORMING CODEBOOK DESIGN AND RESOURCE SCHEDULING", the entire disclosure of which is hereby incorporated by reference.

Technical Field

Embodiments generally may relate to the field of wireless communications and, more particularly to beamforming in wireless communication networks.

Background

Wireless communications standards such as the third generation partnership project (3 GPP) Long Term Evolution, LTE and LTE- Advanced (LTE-A) wireless telecommunication technologies may use Multiple Input Multiple Output (MIMO) which employs multiple transmit antennas and multiple receive antennas to provide high data rates. Beamforming is a MFMO technique that allows transmissions to be focused on specific areas of a cell by using multiple antennas to control the direction of a transmitted wireless signal by appropriately weighting the magnitude and phase of individual antenna signals. The signals are weighted so that they can be added constructively in the direction of a target transmitter or receiver and can be added destructively in the direction of potentially interfering devices.

As wireless communication standards evolve from fourth generation (4G) to fifth generation (5G) and beyond, it is likely that network capacity will be expanded by making use of higher frequency radio waves than the range currently used by LTE and LTE-A. For example, it has been suggested that frequencies above 6 GHz or above 10 GHz could be used. Millimeter wave (mmW) communication has been considered as an important technology to be employed for the future 5G mobile system. One of the problems related to such high frequency transmission is the severe path loss and the limited penetration capability, which reflects into a limited coverage capability (i.e., the coverage radius is reduced). In order to cope with this, very narrow bandwidths, with high beamforming gains, have been studied. Narrow beams with high gains are beneficial for the coverage distance, but they have the disadvantage that the narrower the beam is, the longer time that is typically used for illuminating the cell (more directions may be covered) and there is more sensitivity to beam direction mismatch potentially caused by the feedback delay and other beam alignment imperfections. Considering the fact that typically only few beams can be transmitted in the same time slot (given that an access point (AP) is equipped with multiple beamformers) it follows that if the beams are narrow, a smaller portion of the cell can be covered at the same time. Depending on the user equipments (UEs) distribution, this solution might be inefficient, resulting into a lower throughput and area spectrum efficiency (bits/s/Hz/m ² ).

Brief Description of the Drawings Embodiments described herein are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements:

Figure 1 schematically illustrates a wireless communication system comprising individual beamformers each capable of transmitting beams of variable beamwidths;

Figure 2 schematically illustrates an example set of heterogeneous beams spanning a sector of 120° of a cell, from which a given beamformer can select;

Figure 3 schematically illustrates a configuration of two different beamwidths adapted to serve three user equipments currently present in the cell;

Figure 4 schematically illustrates transmission of a plurality of different reference signals that distinguish between different beamwidths and are transmitted in a series of transmission time intervals (TTIs);

Figure 5 is a flowchart schematically illustrating how a beamformer is scheduled by the wireless network to select a particular beamwidth from a plurality of possible beamwidths depending upon evaluation of a scheduling metric;

Figure 6 schematically illustrates components of an electronic device in which embodiments according to the present technique can be implemented;

Figure 7 is a flowchart schematically illustrating a process implemented in an access point for configuring one or more beamforming is depending upon measurement measurement results received from a user equipment; Figure 8 is a flowchart schematically illustrating a process implemented on a user equipment providing measurement results feeding back to an access point, information to distinguish between respective signal qualities of different beamwidths;

Figure 9 schematically illustrates components able to read instructions from the machine- readable medium for performing method according to the present technique;

Figure 10 schematically illustrates simulation results showing an average number of co- scheduled user equipments for different cell loads providing a performance comparison between fixed beamwidth beamformers and variable beamwidth beamformers; and

Figure 11 schematically illustrates simulation results showing a cumulative distribution function of a number of transmission time intervals to schedule a plurality of user equipments in cells, providing a performance comparison between fixed beamwidth beamformers and variable beamwidth beamformers.

Description of Embodiments

Illustrative embodiments of the present disclosure include, but are not limited to, methods, systems, apparatuses and computer programs for performing beamforming.

The following detailed description refers to the accompanying drawings. The same reference numbers may be used in different drawings to identify the same or similar elements. In the following description, for purposes of explanation and not limitation, specific details are set forth such as particular structures, architectures, interfaces, techniques, etc. in order to provide a thorough understanding of the various aspects of the example embodiments. However, it will be apparent to those skilled in the art having the benefit of the present disclosure that the various aspects of the embodiments claimed may be practiced in other examples that depart from these specific details. In certain instances, descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the example embodiments with unnecessary detail.

In embodiments, instead of having beamformers that generate only beams with a fixed beamwidth, beamformers may generate beams with variable beamwidths. The beams with variable beamwidths and beam directions are chosen from a codebook of beams (each element of the codebook may be characterized by a pair of beamwidth degree and beam direction so that the codebook can be defined by a bi-column matrix), that can be designed in order to maximize the spectrum efficiency and scheduling flexibility. As a result, the beamforming codebook, also known as "beam space", is comprised of heterogeneous beams in the sense that the beams can have different shapes. This provides the Access Point (AP) with additional flexibility in choosing the beamwidth (and the related cell coverage) so that the overall system throughput and/or target scheduling metric can be optimized or at least made to satisfy a performance measure. The scheduling metric may relate to the whole cell or a portion of the cell such as a cell sector and may relate to a quality of service (QoS) parameter such as a signal-to-noise ratio, a latency constraint or a data throughput rate, for example. The terms cell and cell sector may be used interchangeably in this specification depending upon context. Where a beamwidth selection is made depending upon a target metric relating to a cell, t in some examples the target metric may apply to a cell sector or a portion of the cell rather than the entire cell.

With the described codebook, each beam can serve multiple UEs and the decision on the beamwidths and beam directions to be used concurrently (e.g. in the same time slot or "in parallel"), is taken in order to maximize (or at least increase) the bandwidth efficiency or, more in general, to optimize (or at least improve) some other parameters.

In various embodiments:

• A mmW AP may be equipped with multiple beamformers. Each beamformer can cover a different area of the cell such as a different cell sector;

• Each beamformer may be equipped with a finite codebook of beamwidths/directions. The beamformers may be independent from one another, meaning that at the same time or approximately the same time they can generate beams with at least one of different directions or different beamwidths;

• The AP knows the channel quality of each UE in its range (e.g. via measurement feedback), for each resource triple frequency (f), beamwidth (b) and beam direction (d). We consider only a limited number of beamwidths so the amount of information for each UE is manageable from the AP and relevant UE feedback overhead is reasonable.

• Each beam can serve multiple UEs. If a beam is serving multiple UEs, resource multiplexing technique is considered (e.g., frequency division multiple access (FDMA), time division multiple access (TDMA) or code division multiple access (CDMA)).

In embodiments, a heterogeneous beam codebook may be used to optimize or at least improve the overall data rate into the cell, by selecting the best combinations of beams (beamwidths/beam directions) so that each beam covers simultaneously multiple UEs, (e.g., by means of frequency multiplexing). This is possible because the beamformers are equipped with a codebook of beams with different widths and different beamforming gains. The beamforming gain and the beamwidth have an interdependency such that reduced beamwidth implies increased gain and vice versa.

Figure 1 schematically illustrates a communication system 100 comprising an AP 110 and a

UE 150. Examples of APs include evolved NodeBs (eNodeBs), base stations, base substations, picocell/femtocells/microcell base stations or Peer Radio Heads. The AP 110 comprises a first plurality of antennas 112a, 112b,... 112n, which are used cooperatively to generate beams in potentially different directions and potentially having different beamwidths. Similarly, the UE 150 has a second plurality of antennas 152a, 152b,..,152n. The AP 110 and the UE 150 can have different numbers of antennas with respect to each other or the same number of antennas.

The AP 110 comprises a plurality, N, of beamformers 122a, 122b,..,122n and a respective plurality of sets of beamwidth selection circuitry 124a, 124b,..., 124n. Each of the beamformers receives input data for transmission and selects parameters form a codebook 126 defining a predetermined set of bandwidths and beam directions defining a set of possible beam characteristics that can be selectively and independently generated by each of the plurality of beamformers 122a, 122b, ... 122n. In the example arrangement of Figure 1, the codebook 126 is commonly accessible by each set of beamwidth selection circuitry 124a, 124b,.., 124n, but in alternative arrangements each beamformer could have its own codebook or the beamwidths and/or beam directions can be dynamically assigned to the associated beamformer by a controller. Each beamformer controls generation of a beam having a particular shape and direction using at least a subset of the plurality of antennas 122a, 122b, ... ,122n. In the Figure 1 example two different beams 132, 134, are formed by respective different beamformers. A first beam 132 has a narrower beamwidth relative to a second beam 134. The two antenna beam patterns 132, 134 can be directed to one or more than one UE.

The UE 150 illustrated in Figure 1 comprises channel estimation circuitry 160, signal separation circuitry 170 and measurement feedback circuitry 180. The channel estimation circuitry 160 is arranged to process wireless signals received via the plurality of UE antennas. The channel estimation circuitry 160 characterizes the communication channel (the medium) that the received signal has arrived via from the AP 110 to attempt to remove distortion and noise so that the transmitted signal can be more accurately reconstructed from the received signal. One way of performing channel estimation is to transmit a known reference signal or pilot signal and detect the received signal. Alternatively a channel matrix can be used to mathematically correlate a transmitted signal and a received signal.

The measurement feedback circuitry 180 derives information from the channel estimation circuitry 160 to allow the received signal quality of different transmitted beamwidths to be measured. Measurement information for at least a subset of the received beamwidths could be fed back to the AP 110, for example measurement information from only a predetermined number of the highest quality received signals could be fed back to inform the selection of an appropriate beamwidth by one or more of the beamformers 112a, 122b,..122n of the AP 110. In this embodiment, the channel estimation circuitry uses Channel State Information Reference Signals (CSI-RS), but other types of reference signals that allow measurement to distinguish between signals having different beamwidths may be used. Based upon information from the channel estimation circuitry 160, the measurement feedback circuitry 180 of this embodiment sends at least one of a wideband Channel Quality Indicator (CQI), a subband Channel Quality Indicator or a reference signal receive power (RSRP) measurement for one or more received beam back to the AP 1010 via a signal denoted 182 to feed into beamwidth selections made by one or more of the sets of beamwidth selection circuitry 124a, 124b,.., 124n. Measurements other than CQIs and RSRP may be used to feedback information distinguishing between received signals corresponding to different beamwidths in alternative embodiments.

The beamformers 122a, 122b, ... ,122n may allow a variable beamwidth to be provided via a single beamformer by, for example:

1) changing the gain of the antennas. This is possible both when an array of antennas are used and when analog beamformers are used;

2) use a digital beamformer and change a the matrix of magnitude and phase weights appropriately to generate a different beamwidth.

Digital beamformers are typically more complex to implement than analog beamformers, but each have their own advantages. In some embodiments hybrid digital/analog beamformers may be used to generate the selectively variable beamwidth according to the present technique.

One example design of heterogeneous beam space/codebook that could be implemented as the codebook 126 of the Figure 1 embodiment is schematically illustrated in Fig. 2. As shown in Fig. 2, the heterogeneous beam codebook is comprised of one beam of 120° beamwidth, two beams 220 of 60° beamwidth 220, four beams 230 of 30° beamwidths, and eight beams 240 of 15° beamwidth. For example, where two beamformers are provided, each beamformer can select between the four different beamwidths: 15°, 30°, 60° and 120°. For the 15° beamwidth, eight different alternative beam directions can be chosen, for the 30° beamwidth, four different alternative beam directions can be chosen and so on.

The best combination of selected beam parameters can be found in subsequent refinement operations by exploiting the nature of the beamwidths. In Fig. 3, three UEs, namely UE1 312, UE2 314 and UE3 316 are served by a mmW AP 310 that can generate simultaneously only two beams 330, 340 with different widths, pointing to different directions and having respective different beamforming gains.

A first search in the cell, may be conducted with the narrowest beam of the plurality of possible beamwidths so that the radius of the cell is maximized. This narrow beam search detects that three UEs 312, 314, 316 are present in the cell and their position. The optimal beam directions to maximize or at least increase or provide a local maximum throughput are then established and the throughput that will be achieved is computed. The information about the position of the UEs is then used in one or more refinement operations to decide whether a better choice of beam directions and/or beamwidths can be taken in order to increase the throughput. For example two geographically close UEs can be covered by the same beam with a larger width. As shown for the UEs 312, 314, which are simultaneously covered by the beam 330 in the Figure 3 embodiment.

The codebook 126 can be based on an "elementary beam" with beamwidth ^ nin _{? e} .g., the narrowest beam that can be generated by one of the beamformers 1221, 122b,.., 122n. The beam codebook may be comprised of those beams with widths being exact multiples of the elementary beam. The AP is equipped with B > 1 beamformers, and each beamformer covers a specific area: the cell can be divided in several non-overlapped sectors of ^{3i>0 s} degrees. Then the codebook can be designed to include the beamwidths ^Zw mtn > ^3vt · 360 - /5} p _{or a} fixed beamwidth ^w for a specific beamformer, the covered area can be divided in several regions, each of which can be uniquely identified by an index P— ^Q> — ^{> F} max- - ¹ (where F ^{max = ~} ), such that V identifies the region {P ^w * 0 O ^w} . Then for each beamformer the area covered b the transmitted beam is identified by the vector ^V b = ( ^w b> Vb

Let us assume for example that the mmW AP is equipped with three analog beamformers

* ' ^ each of which is capable of transmitting a beam with different widths (from the codebook) and of covering a dedicated sector of 120°. if the "elementary beam" has the width 'miii — ¹ ₃ the codebook can be for example designed such that the possible beamwidths are v = {15°,, 30°, 45°, 60°, 7.5° , 90°, 105° , 120° } _{A more efflcient solution would}

? __ -i cjo '3fp ftno i fy~ t

be to reduce the possible choice to > * ·' so that a larger width may be a multiple of the previous one.

Beamformed reference signal transmission for CSI feedback

In some embodiments, the radio resource (beam and time-frequency resource etc.) scheduling process described herein may assume the channel state information (CSI) of a UE associated with each detected beam defined in the heterogeneous codebook is to be reported by the UE to the AP. Alternatively, measurement information corresponding to only a subset of detected beams may be reported back. The CSI can be, for example, wideband channel quality indicator (CQI) or subband CQIs or the reference signal receive power. To measure or calculate a beam specific CSI, the UE can be configured by multiple CSI reference signals (RSs), each of which is transmitted via a corresponding beam defined in the codebook 126. For instance, with the above codebook example, a UE in a particular sector can be configured with fifteen CSI-RSs, which include eight CSI-RSs with 15 ^° beamwidth, four CSI-RSs with 30° beamwidth, two CSIs with 60 beamwidth and one CSI with 120 beamwidth. One possible timing configuration of above 15 CSI-RS processes can be illustrated in Fig. 4.

As shown in Fig. 4, fifteen CSI-RS processes with different periodicities can be configured. Due to the constraint in some embodiments of a shared physical analog beamformer (other embodiments may use digital or hybrid beamformers), those CSI-RSs scheduled in the same transmission time interval (TTI) can be transmitted from different symbols. The AP can further configure a feedback mode of UE for the configured CSI-RSs, for example, the UE can be requested to periodically report only M-best detected beams in terms of wideband CQI, where M is a non-zero integer. By virtue of the CSI information or other measurement information reported from all the UEs in the coverage, the AP can schedule the radio resources in an efficient manner to optimize or at least improve certain performance metrics. One scheduling procedure example is described in the following. Figure 4 schematically illustrates how fifteen different reference signals are distributed across eight TTIs. A first TTI 410 comprises: a 15 beamwidth CSI-RS 412; a 30 ^° beamwidth CSI-RS 414; a 60 ^° beamwidth CSI-RS 416; and a 120 ^° beamwidth CSI-RS 418. A second TTI 412 comprises a 15 ^° beamwidth CSI-RS 420. A third TTI 414 comprises a 15 ^° beamwidth CSI-RS 432 and a 30 ^° beamwidth CSI-RS 434. A fourth TTI 416 comprises a 15 ^° beamwidth CSI-RS 442. A fifth TTI 418 comprises: a 15 ^° beamwidth CSI-RS 452; a 30 ^° beamwidth CSI-RS 454; and a 60 ^° beamwidth CSI-RS 456. A sixth TTI 420 comprisesa 15 ^° beamwidth CSI-RS 462. A seventh TTI 422 comprises a 15 ^° beamwidth CSI-RS 472 and a 30 ^° beamwidth CSI-RS 474. Finally, an eight TTI 424 comprises a 15 ^° beamwidth CSI-RS 482.

Beam resource scheduling example

A flowchart schematically illustrating one possible use of the beams codebook (i.e. plurality of predetermined beamwidths and/or beam direction combinations) is illustrated in Fig. 5. As shown in Fig. 5, process element 510 of the flowchart involves setting all the beamformers to be unscheduled. Process elements 520 to 550 are repeated for all unscheduled beamformers. Specifically, an unscheduled beamformer sets a particular beamwidth in process element 520 and determines the CSI information or other UE-based signal measurement information by searching in the UEs for all beamwidths and beam directions. At process element 530 the beams with the given beamwidth are searched to find an optimal (or at least preferred) beam direction to maximize (or at least satisfy a desired threshold value) corresponding to a target scheduling metric for the cell or cell sector. The target scheduling metric may comprise, for example, simply selecting the beam direction for which the signal received at the UE has the best quality for the given beam direction based on the corresponding received reference signal or may additionally comprise, for example, one or more other quality of service parameter. In other examples, the target scheduling metric may correspond to a beam direction that maximizes an overall throughput in a cell sector covered by the corresponding beamformer. The beam direction selection of process element 530 is repeated for each beamwidths from i=0 up to the maximum beamwidth in the chosen range (i=i_max). Once the best beam direction has been established by establishing the maximum scheduling metric for each of the plurality of beamwidths, the process proceeds to process element 540. The beamwidth which achieves the largest scheduling metric by the found optimal (or best tested) beam direction is selected in process element 540. As a result, the unscheduled beamformer is set by the selected beam direction and beamwidth which has been found to achieve the maximum scheduling metric in process element 550.

As used herein, the term "circuitry" may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules or units. In some embodiments, circuitry may include logic, at least partially operable in hardware.

Embodiments described herein may be implemented into a system using any suitably configured hardware and/or software. Figure 6 illustrates, for one embodiment, example components of an electronic device 600. In embodiments, the electronic device 600 may be, implement, be incorporated into, or otherwise be a part of a user equipment (UE), an evolved NodeB (eNB), and/or an access point (AP) that may be an eNB in some embodiments. In some embodiments, the electronic device 600 may include application circuitry 602, baseband circuitry 604, Radio Frequency (RF) circuitry 606, front-end module (FEM) circuitry 608 and one or more antennas 610, coupled together at least as shown.

The application circuitry 602 may include one or more application processors. For example, the application circuitry 602 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors, application processors, etc.). The processors may be coupled with and/or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems to run on the system.

The baseband circuitry 604 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 604 may include one or more baseband processors and/or control logic to process baseband signals received from a receive signal path of the RF circuitry 606 and to generate baseband signals for a transmit signal path of the RF circuitry 606. Baseband processing circuity 604 may interface with the application circuitry 602 for generation and processing of the baseband signals and for controlling operations of the RF circuitry 606. For example, in some embodiments, the baseband circuitry 604 may include a second generation (2G) baseband processor 604a, third generation (3G) baseband processor 604b, fourth generation (4G) baseband processor 604c, and/or other baseband processor(s) 604d for other existing generations, generations in development or to be developed in the future (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 604 (e.g., one or more of baseband processors 604a-d) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 606. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry 604 may include Fast-Fourier Transform (FFT), precoding, and/or constellation mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry 604 may include convolution, tail-biting convolution, turbo, Viterbi, and/or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments.

In some embodiments, the baseband circuitry 604 may include elements of a protocol stack such as, for example, elements of an evolved universal terrestrial radio access network (EUTRAN) protocol including, for example, physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), and/or radio resource control (RRC) elements. A central processing unit (CPU) 104e of the baseband circuitry 604 may be configured to run elements of the protocol stack for signaling of the PHY, MAC, RLC, PDCP and/or RRC layers. In some embodiments, the baseband circuitry may include one or more audio digital signal processor(s) (DSP) 604f. The audio DSP(s) 604f may be include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments.

The baseband circuitry 604 may further include memory/storage 604g. The memory/storage 604g may be used to load and store data and/or instructions for operations performed by the processors of the baseband circuitry 604. Memory/storage for one embodiment may include any combination of suitable volatile memory and/or non-volatile memory. The memory/storage 604g may include any combination of various levels of memory/storage including, but not limited to, read-only memory (ROM) having embedded software instructions (e.g., firmware), random access memory (e.g., dynamic random access memory (DRAM)), cache, buffers, etc. The memory/storage 604g may be shared among the various processors or dedicated to particular processors.

Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry 604 and the application circuitry 602 may be implemented together such as, for example, on a system on a chip (SOC).

In some embodiments, the baseband circuitry 604 may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 104 may support communication with an evolved universal terrestrial radio access network (EUTRAN) and/or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN). Embodiments in which the baseband circuitry 604 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

RF circuitry 606 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 606 may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. RF circuitry 606 may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry 608 and provide baseband signals to the baseband circuitry 604. RF circuitry 606 may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry 604 and provide RF output signals to the FEM circuitry 608 for transmission.

In some embodiments, the RF circuitry 606 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry 606 may include mixer circuitry 606a, amplifier circuitry 606b and filter circuitry 606c. The transmit signal path of the RF circuitry 606 may include filter circuitry 606c and mixer circuitry 606a. RF circuitry 606 may also include synthesizer circuitry 606d for synthesizing a frequency for use by the mixer circuitry 606a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 606a of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry 608 based on the synthesized frequency provided by synthesizer circuitry 606d. The amplifier circuitry 606b may be configured to amplify the down-converted signals and the filter circuitry 606c may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry 604 for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although example embodiments are not limited to this. In some embodiments, mixer circuitry 106a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry 606a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 606d to generate RF output signals for the FEM circuitry 608. The baseband signals may be provided by the baseband circuitry 604 and may be filtered by filter circuitry 606c. The filter circuitry 606c may include a low-pass filter (LPF), although the scope of the embodiments is not limited in this respect.

In some embodiments, the mixer circuitry 606a of the receive signal path and the mixer circuitry 106a of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and/or upconversion respectively. In some embodiments, the mixer circuitry 606a of the receive signal path and the mixer circuitry 606a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry 606a of the receive signal path and the mixer circuitry 606a may be arranged for direct downconversion and/or direct upconversion, respectively. In some embodiments, the mixer circuitry 606a of the receive signal path and the mixer circuitry 606a of the transmit signal path may be configured for super-heterodyne operation.

In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry 606 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry 604 may include a digital baseband interface to communicate with the RF circuitry 606.

In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect.

In some embodiments, the synthesizer circuitry 606d may be a fractional-N synthesizer or a fractional N/N+l synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 606d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider.

The synthesizer circuitry 606d may be configured to synthesize an output frequency for use by the mixer circuitry 606a of the RF circuitry 606 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 606d may be a fractional N/N+l synthesizer.

In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although example embodiments are not limited to this. Divider control input may be provided by either the baseband circuitry 604 or the applications processor 602 depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the applications processor 602.

Synthesizer circuitry 606d of the RF circuitry 606 may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DP A). In some embodiments, the DMD may be configured to divide the input signal by either N or N+l (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle. In some embodiments, synthesizer circuitry 606d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry 606 may include an IQ/polar converter.

FEM circuitry 608 may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas 610, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry 106 for further processing. FEM circuitry 608 may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 606 for transmission by one or more of the one or more antennas 610.

In some embodiments, the FEM circuitry 608 may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include a low-noise amplifier (LNA) to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry 606). The transmit signal path of the FEM circuitry 108 may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry 606), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 610.

In some embodiments, the electronic device 600 may include additional elements such as, for example, memory/storage, display, camera, sensor, and/or input/output (I/O) interface.

In embodiments where the electronic device 600 is, implements, is incorporated into, or is otherwise part of an access point (AP) or an e B, baseband circuitry 604 may include a plurality of beamformers that may be analog beamformers. The baseband circuitry 604 may be to generate a plurality of beams, each beam having a variable beamwidth, receive measurement results from UEs in a cell served by the AP, and determine a beamwidth for each of the plurality of beams based at least in part on the measurement results. In embodiments, the RF circuitry 606 may be to receive signals from the UEs corresponding to the measurement results. In embodiments, the baseband circuitry 604 may be to configure CSI-RSs corresponding to a plurality of beamwidth and beam direction combinations and the RF circuitry 106 may be to transmit the CSI-RSs to the UEs.

In embodiments where the electronic device is, implements, is incorporated into, or is otherwise part of a UE, the RF circuitry 606 may be to receive a set of CSI-RSs corresponding to a plurality of beamwidth and beam direction combinations from an AP and transmit measurement results to the AP based at least in part on the received set of CSI-RSs. In embodiments, the baseband circuitry 604 may be to determine the measurement results.

In some embodiments, the electronic device of Figure 6 may be configured to perform one or more processes, techniques, and/or methods as described herein, or portions thereof. One such process is depicted in Figure 7. For example, in embodiments where the electronic device is, implements, is incorporated into, or is otherwise part of an AP or a portion thereof, the process may include receiving measurement results from a plurality of UEs in a cell served by the AP and configuring each of a plurality of beamformers at the AP based at least in part on the received measurement results. In embodiments, at process element 710 process may include configuring channel state information reference signals (CSI-RSs) or other suitable reference signals and, at process element 720 transmitting the CSI-RSs to UEs in the cell. The measurement results from the UEs in the cell may be generated and transmitted by the UEs based at least in part on the transmitted CSI-RSs. In embodiments, the process may include at process element 740, determining settings for the plurality of beamformers and configuring the beamformers may be performed based at least in part on the determined settings. In embodiments, the process may include at process element 760 scheduling traffic for the UEs in the cell according to the determined beamformer settings.

In some embodiments, the electronic device of Figure 6 may be configured to perform one or more processes, techniques, and/or methods as described herein, or portions thereof. One such process is depicted in Figure 8. For example, in embodiments where the electronic device is, implements, is incorporated into, or is otherwise part of a UE, or a portion thereof, the process may include at process element 810, receiving a set of CSI-RSs corresponding to a plurality of beamwidth and beam direction combinations from an AP; and at process element 820, transmitting measurement results to the AP based at least in part on the received set of CSI-RSs. In embodiments, the process may include, at process element 830, receiving a signal from the AP based at least in part on the transmitted measurement results and communicating through the AP. At process element 840 the AP the UE communicates with the AP using the scheduled beam having a beamwidth selected, at least in part, based upon the measurement results.

FIG. 9 is a block diagram illustrating components, according to some example embodiments, able to read instructions from a transient or non-transient machine-readable or computer-readable medium (e.g., a machine-readable storage medium or a transmission medium) and perform any one or more of the methodologies discussed herein. Specifically, FIG. 9 shows a diagrammatic representation of hardware resources 900 including one or more processors (or processor cores) 910, one or more memory/storage devices 920, and one or more communication resources 930, each of which are communicatively coupled via a bus 940.

The processors 910 (e.g., a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a digital signal processor (DSP) such as a baseband processor, an application specific integrated circuit (ASIC), a radio-frequency integrated circuit (RFIC), another processor, or any suitable combination thereof) may include, for example, a processor 912 and a processor 914. The memory/storage devices 920 may include main memory, disk storage, or any suitable combination thereof.

The communication resources 930 may include interconnection and/or network interface components or other suitable devices to communicate with one or more peripheral devices 904 and/or one or more databases 906 via a network 908. For example, the communication resources 930 may include wired communication components (e.g., for coupling via a Universal Serial Bus (USB)), cellular communication components, Near Field Communication (NFC) components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components.

Instructions 950 may comprise software, a program, an application, an applet, an app, or other executable code for causing at least any of the processors 910 to perform any one or more of the methodologies discussed herein. The instructions 950 may reside, completely or partially, within at least one of the processors 910 (e.g., within the processor's cache memory), the memory/storage devices 920, or any suitable combination thereof. Furthermore, any portion of the instructions 950 may be transferred to the hardware resources 900 from any combination of the peripheral devices 904 and/or the databases 906. Accordingly, the memory of processors 910, the memory/storage devices 920, the peripheral devices 904, and the databases 906 are examples of computer-readable and machine-readable media.

Figure 10 and Figure 11 provide simulation results illustrating performance improvements that may be achieved by implementing a beamformer capable of generating beams having a plurality of different beamwidths and a comparison is pefromed with a beamformer capable of generating fixed width beams. For the simulations, the wireless network arrangement was such that the AP was equipped with three beamformers, each covering a sector of 120°, the AP being able to generate three beams in the same time slot (synchronized). The three cell sectors (and the beamformers performance) were then independently studied. The terms "cell" and "cell sector" may be used interchangeably in this specification depending upon context.

In the simulations, three different cell loads are considered: 20 UEs, 40 UEs and 60 UEs served in the cell. For each of the three different cell load, the azimuth of each UE is uniformly random distributed over the 120° cell coverage. The fixed beamwidth beamformer can transmit thirty -two non-overlapped beams of 3.75° beamwidth to fully cover the cell. The variable beamwidth beamformer can transmit six different beamwidths: 120°, 60°, 30°, 15°, 7.5° and 3.75°. Since beamwidth and gain are related parameters, the beam with narrowest beamwidth offers the largest beamforming gain, is defined as "gmax". It is assumed for the simulations that the beamforming gain decreases by 3dB when the beamwidth increases by two times. As a result, six different beamforming gains, namely gmax, gmax-3dB, gmax-6dB, gmin=gmax- 32dB, are provided by the variable beamwidth beamformer. The beamforming gain of each UE was uniformly random distributed in the range of [gmin - 3dB, gmax). The UE beamforming gain takes both the pathloss and the relevant throughput into account. In the simulations, a UE can be served by a beam if it is located in the azimuth coverage of the beam, and the beamforming gain offered by the beam fulfills the specified UE beamforming gain.

In the simulations, two relevant performance metrics are studied. Figure 10 schematically illustrates simulation results showing an average number of co-scheduled UEs for different cell loads providing a comparison between a fixed beamwidth beamformer and a variable beamwidth beamformer according to the present technique. Figure 11 schematically illustrates simulation results comprising a cumulative distribution function (CDF) of a number of transmission time intervals used to schedule all UEs in a cell.

The first performance metric is the average number of UEs which can be scheduled in the same TTI. The more UEs can be co-scheduled in the same time, the more scheduling flexibility is offered by the beamformer. As shown in the bar chart Fig. 10, the variable beamwidth beamformer can co-schedule approximately twice as many UEs as the fixed beamwidth beamformer for each to the three different cell loads illustrated (20, 40 and 60 UEs per sector). As a result, improved scheduling flexibility can be provided by the variable beamwidth beamformer relative to the fixed beamwidth beamformer.

The scheduling flexibility can be translated into the latency gain in some cases. Figure 11 illustrates the CDF of smallest number of TTIs used to serve all the UEs in the cell. It can be seen from the simulation results of Figure 11 that due to the increased scheduling flexibility, the variable beamwidth beamformer can serve all the UEs in the cell with about 30% fewer TTIs than that of the fixed beamwidth beamformer. In particular, the CDF 1110 represents a variable width beamformer with a 20 UE cell load whereas the CDF 1112 represents a fixed width beamformer with a 20 UE cell load. The CDF 1120 represents a variable width beamformer with a 40 UE cell load whereas the CDF 1122 represents a fixed width beamformer with a 40 UE cell load. The CDF 1130 represents a variable width beamformer with a 60 UE cell load whereas the CDF 1132 represents a fixed width beamformer with a 60 UE cell load.

Thus according to the present technique whereby a selectively variable beamwidth rather than a fixed beamwidth is provided by a given beamformer, improved bandwidth efficiency and reduced latency can be achieved for a given cell load, which may result in improved system performance overall in the cell or cell sector.

EXAMPLES

Example 1 may include an access point (AP) in the future cellular network configured to perform the following:

configuring a set of CSI reference signals (CSI-RS) for all the camped UEs in the cell; and

receiving measurement results from all the served UEs about the configured CSI-RSs; and

determining a set of beamformer settings to achieve the optimal scheduling metric; and configuring all the beamformers according to the selected beamformer settings;

scheduling UEs traffic according to the optimal beamformer settings. Example 2 may include the AP of the example 1 or some other example herein, wherein the AP is equipped with several analog beamformers, and each analog beamformer transmits beamformed signals independently from the other analog beamformers.

Example 3 may include the AP of example 1 or some other example herein, wherein the set of configured CSI-RSs includes several subsets of beamformed CSI-RSs. Each subset of CSI- RSs includes several beamformed CSI-RSs with non-overlapped beam directions and same beamwidth, and the CSI-RSs in the same subset can be configured with same periodicity. Different subsets of CSI-RSs have different beamwidths, and can be configured with different periodicity accordingly.

Example 4 may include the AP of example 1 or some other example herein, wherein the measurement results about the configured CSI-RSs from the UEs may refer to the reference signal receive power or reference signal receive quality depending on the S R of received reference signal, or certain channel quality indicator derived from the SNR of the received reference signal.

Example 5 may include the AP of example 1 or some other example herein, wherein the optimal scheduling metric determined is calculated by a scheduler located in the AP, which is configured to perform the following

storing all the measurement results in the example 4 in an internal memory;

searching an optimal beam direction and beamwidth in the order of increasing beam direction first and then beamwidth, to maximize the target scheduling metric.

Example 6 may include a UE in the future cellular network camping on an AP of example 1 or some other example herein, wherein the UE is configured to perform the following: receiving the configuration of CSI-RSs from the AP;

measuring the receive power or quality of the configured CSI-RSs;

reporting the measurement results periodically or on an event-triggered basis for the configured CSI-RSs to the AP.

Example 7 may include an access point (AP) comprising circuitry to: generate a plurality of beams, each beam having a variable beamwidth; receive measurement results from user equipments (UEs) in a cell served by the AP; and determine a beamwidth for each of the plurality of beams based at least in part on the received measurement results. Example 8 may include the AP of example 7 or some other example herein, wherein the AP is a millimeter wave (mmW) AP.

Example 9 may include the AP of example 7 or some other example herein, wherein the AP is an evolved node B (e B).

Example 10 may include the AP of example 7 or some other example herein, wherein the circuitry to generate a plurality of beams includes a plurality of beamformers.

Example 11 may include the AP of example 10 or some other example herein, wherein the beamformers are analog beamformers.

Example 12 may include the AP of example 10 or some other example herein, wherein the each of the beamformers serves a sector of the cell.

Example 13 may include the AP of example 12 or some other example herein, wherein the sectors served by the beamformers do not overlap.

Example 14 may include the AP of example 7 or some other example herein, wherein the circuitry is to configure a set of channel state information (CSI) reference signals (RSs) and send the CSI-RSs to the UEs.

Example 15 may include the AP of any one of example 7-14 or some other example herein, wherein the circuitry includes baseband circuitry and/or radio frequency (RF) circuitry.

Example 16 may include a method of configuring a plurality of beamformers at an access point (AP) in a wireless cellular network comprising: receiving measurement results from a plurality of user equipments (UEs) in a cell served by the AP; and configuring each of the plurality of beamformers based at least in part on the received measurement results.

Example 17 may include the method of example 16 or some other example herein, further comprising transmitting channel state information reference signals (CSI-RSs) corresponding to a plurality of beamwidth and beam direction combinations to the UEs, wherein the measurement results are based at least in part on the transmitted CSI-RSs.

Example 18 may include the method of example 17 or some other example herein, wherein the beamwidth and beam direction combinations are selected from a codebook of beams with different widths, wherein the widths are multiples of an elementary beam width.

Example 19 may include the method of example 18 or some other example herein, wherein the elementary beam width is the narrowest beam width that can be generated by a beamformer in the plurality of beamformers. Example 20 may include the method of example 18, wherein the different widths are an ordered set of widths such that each width that is not the smallest width is a multiple of the previous width in the ordered set of widths.

Example 21 may include a user equipment (UE) comprising circuitry to receive a set of channel state information reference signals (CSI-RSs) corresponding to a plurality of beamwidth and beam direction combinations from an access point; and transmit measurement results to the AP based at least in part on the received set of CSI-RSs.

Example 22 may include the UE of example 21 or some other example herein, wherein the circuitry is further to receive a signal from the AP based at least in part on the transmitted measurement results.

Example 23 may include the UE of example 21 or some other example herein, wherein the circuitry is to transmit a measurement result for each CSI-RS received.

Example 24 may include the UE of example 21 or some other example herein, wherein the circuitry is to transmit measurement results for a predefined number of CSI-RS received.

Example 25 may include the UE of example 24 or some other example herein, wherein the measurement results are for the best detected CSI-RSs.

Example 26 may include the UE of example 25 or some other example herein, wherein the best detected CSI-RSs are determined in terms of wideband channel quality indicator (CQI).

Example 27 may include the UE of any one of example 21-26 or some other example herein, wherein the circuitry includes baseband circuitry and/or radio frequency (RF) circuitry.

Example 28 may include a method of communicating with a user equipment (UE) in a wireless cellular network comprising: receiving a set of channel state information reference signals (CSI-RSs) corresponding to a plurality of beamwidth and beam direction combinations from an access point; and transmitting measurement results to the AP based at least in part on the received set of CSI-RSs.

Example 29 may include the method of example 28 or some other example herein, further comprising receiving a signal from the AP based at least in part on the transmitted measurement results.

Example 30 may include the method of example 28 or some other example herein, wherein transmitting measurement results to the AP includes transmitting a measurement result for each CSI-RS received. Example 31 may include the method of example 28 or some other example herein, wherein transmitting measurement results to the AP includes transmitting measurement results for a predefined number of CSI-RS received.

Example 32 may include the method of example 31 or some other example herein, wherein the measurement results are for the best detected CSI-RSs.

Example 33 may include the method of example 32 or some other example herein, wherein the best detected CSI-RSs are determined in terms of wideband channel quality indicator (CQI).

Example 34 may include an apparatus comprising means to perform one or more elements of a method described in or related to any of examples 1-33, or any other method or process described herein.

Example 35 may include one or more non-transitory computer-readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of a method described in or related to any of examples 1-33, or any other method or process described herein.

Example 36 may include an apparatus comprising logic, modules, and/or circuitry to perform one or more elements of a method described in or related to any of examples 1-33, or any other method or process described herein.

Example 37 may include a method, technique, or process as described in or related to any of examples 1-33, or portions or parts thereof.

Example 38 may include a method of communicating in a wireless network as shown and described herein.

Example 39 may include a system for providing wireless communication as shown and described herein.

Example 40 may include a device for providing wireless communication as shown and described herein.

Example 41 may include a method of configuring beamformers as shown and described herein.

Example 42 may include a system for configuring beamformers as shown and described herein. Example 43 may include a device for configuring beamformers as shown and described herein.

Example 44 may include a means for performing one or more elements of a method described in or related to any of examples 1-33, or any other method or process described herein.

Example 45 may include beamforming circuitry, for use in an Access Point of a wireless communication network, the Access Point having an associated cell corresponding to a predicted geographical coverage area of one or more radio signals transmitted from the Access Point, the beamforming circuitry comprising: a beamformer to generate a beam for wireless transmission in the cell, the communication signal having a beamwidth selectable from a plurality of different beamwidths; and beamwidth selection circuitry to select one of the plurality of different beamwidths to be generated by the beamformer to serve at least one User Equipment (UE) located in the cell, wherein the selected beamwidth depends upon a target scheduling metric for the cell.

Example 46 may include the beamforming circuitry of example 45 or some other example herein, wherein the beamformer is arranged to generate the beam in a plurality of different beam directions within the cell and wherein the beamwidth selection circuitry is arranged to determine the selected beamwidth to serve the at least one UE located in the cell depending upon a combination of one of the plurality of beamwidths and one of the plurality of different beam directions to satisfy the target scheduling metric for the cell.

Example 47 may include the beamforming circuitry of example 45 or 46 or some other example herein, wherein the beamforming circuitry comprises a plurality of beamformers and a respective plurality of beamwidth selection circuitry to independently set at least one of beamwidths or beam directions of different ones of the plurality of beamformers in the Access Point to satisfy the target scheduling metric.

Example 48 may include the beamforming circuitry of example 47 or some other example herein, wherein each of the plurality of beamformers provides wireless communication coverage to a respective sector of the cell.

Example 49 may include the beamforming circuitry of example 48 or some other example herein, wherein the plurality of sectors corresponding respectively to the plurality of beamformers comprises a plurality of non-overlapping sectors of the cell. Example 50 may include the beamforming circuitry of example 48 or 49 or some other example herein, wherein the plurality of beamformers are arranged such that the plurality of selected beamwidths together span less than or equal to a full span of the cell depending upon a maximum for the target scheduling metric of the cell.

Example 51 may include the beamforming circuitry of any one of examples 45-50 or some other example herein, wherein the beamformer is arranged to generate an elementary beam having a mimimum beamwidth amongst the plurality of beamwidths and wherein the beamforming circuitry is arranged to scan the cell using the elementary beam to determine locations of the at least one UEs to be served in the cell.

Example 52 may include the beamforming circuitry of example 51 or some other example herein, wherein the plurality of beams is selected from a codebook of beams comprising the elementary beam and one or more further beams corresponding to different exact multiples of the minimum beamwidth corresponding to the elementary beam.

Example 53 may include the beamforming circuitry of any one of examples 45-51 or some other example herein, wherein the target scheduling metric depends upon measurement results reported by the at least one UE to the Access Point, the measurement results being based upon measurements of reference signals corresponding to the generated beam(s).

Example 54 may include the beamforming circuitry of any of examples 45-53 or some other example herein, wherein the beamformer is arranged to generate a Channel State Information Reference Signal (CSI-RS) corresponding to at least one of given beamwidth or a given beam direction of the generated beam.

Example 55 may include the beamforming circuitry of example 54 or some other example herein, wherein the beamformer is allocated to serve a cell or cell sector having a maximum span in degrees and wherein the beamformer is arranged to generate a number of different CSI-RSs for a given beamwidth corresponding to the maximum span divided by the given beamwidth.

Example 56 may include the beamforming circuitry of any one of examples 45 to 55 or some other example herein, wherein the beamformer is arranged to serve a plurality of UEs using the generated beam and wherein the beam is generated using one of frequency division multiple access, time division multiple access or code division multiple access to multiplex the generated beam to the plurality of UEs being served. Example 57 may include the beamforming circuitry of any one of examples 45 to 56 or some other example herein, wherein the target scheduling metric comprises selecting at least one beamwidth and beam direction combination to perform at least one to of the following for a cell or a cell sector: increase throughput or increase an overall data rate or increase a bandwidth efficiency or cover a maximum of number of UEs located in the cell or the cell sector.

Example 58 may include an Access Point comprising the beamforming circuitry of any one of examples 45 to 57 or some other example herein.

Example 59 may include the Access Point of example 58 or some other example herein, comprising one of an ENodeB, a base station, a base station subsystem, a picocell, a microcell, a femtocell, or a Peer Radio Head.

Example 60 may include the Access Point of example 58 or 59 or some other example herein, wherein the target scheduling metric depends upon Channel State Information from a non-zero subset or a full set of all UEs detected to be in the cell or cell sector served by the beamforming circuitry.

Example 61 may include the Access Point of any one of examples 58 to 60 or some other example herein, wherein the beamformer is arranged to generate at least one beam specific Channel State Information Reference Signal (CSI-RS) corresponding to each of the plurality of different beamwidths.

Example 62 may include the Access Point of example 61 or some other example herein, wherein the Access Point is arranged to schedule CSI-RSs corresponding to two or more different beamwidths in a single Transmission Time Interval using different symbols.

Example 63 may include the Access Point of any one of examples 58-62 or some other example herein, comprising a plurality of beamformers and a respective plurality of beamwidth selection circuitry for independently setting at least one of beamwidths or beam directions of different ones of the plurality of beamformers by selecting from values in a codebook comprising a predetermined set of combinations of beamwidths and beam directions.

Example 64 may include the Access Point of any one of examples 58-63 or some other example herein, wherein the Access Point is arranged to transmit information to one or more of the at least one UEs located in the cell, information specifying a feedback mode for reporting back information for the target scheduling metric for the cell. Example 65 may include the Access Point of example 64 or some other example herein, wherein the feedback information comprises wideband CQI information for a beam.

Example 66 may include the Access Point of example 65 or some other example herein, wherein the feedback mode comprises periodically reporting from the UE to the Access Point wideband CQI information for a subset of beams detected by the UE, the subset comprising a number M of the best detected beams.

Example 67 may include measurement circuitry for use in a User Equipment (UE) of a wireless communication network, the measurement circuitry being arranged to:

measure a plurality of reference signals received at the UE, the reference signals distinguishing between beams having a plurality of different beamwidths and generated by a beamformer in an Access Point; and

provide the measurements to a transmitter of the UE for transmission to the Access Point; wherein the measurements are used by the Access Point to selects a beamwidth of a scheduled communication between the beamformer and the UE.

Example 68 may include the measurement circuitry of example 67 or some other example herein, wherein the beamformer is arranged to cover at least a portion of a cell sector having a predetermined sector size and wherein for each different beamwidth there is a number of reference signals corresponding to the predetermined sector size divided by the beamwidth, each of the number of reference signals corresponding to a different beam direction within the cell sector.

Example 69 may include the measurement circuitry of examples 67 or 68 or some other example herein, arranged to receive from the Access Point an indication of a feedback mode for transmitting the measurements to the Access Point.

Example 70 may include the measurement circuitry of any one of examples 67-69 or some other example herein, wherein the measurements provided to the transmitter comprise one of wideband channel quality indicators (CQI) or subband CQI indicators or reference signal receive power.

Example 71 may include the measurement circuitry of any one of examples 67-70 or some other example herein, wherein the reference signals are Channel State Information Reference Signals. Example 72 may include a User Equipment (UE) comprising the measurement circuitry of any one of examples 67-71 or some other example herein.

Example 73 may include the UE of example 72 or some other example herein, comprising a touchscreen to receive input from a user for processing by the UE.

Example 74 may include machine executable instructions stored on a transient or non- transient machine readable medium, the instructions being operable upon execution by one or more processors accessible to an Access Point (AP), to transmit a beam from the Access Point to a UE, the machine executable instructions comprising:

instruction(s) to generate using a beamformer a plurality of beams having a respective plurality of different beamwidths, the beams including reference signals to distinguish between at least two different beamwidths;

instruction(s) to transmit the generated set of beams to at least one User Equipment (UE) located in a cell coverage area of the beamformer;

instructions to receive from the at least one UE, measurement information for the reference signals corresponding to at least a subset of the received beamwidths;

instructions to schedule a communication between the Access Point and the at least one UE using one of the plurality of different beamwidths selected for the beamformer based at least in part on the measurement information.

Example 75 may include the machine executable instructions of example 74 or some other example herein, wherein the communication is scheduled based upon a cell performance metric.

Example 76 may include the machine executable instructions of example 75 or some other example herein, wherein the measurement information is based on at least one of a received power or a received signal quality or a Channel Quality Indicator corresponding to a received reference signal.

Example 77 may include machine executable instructions stored on a transient or non- transient machine readable medium, the instructions being operable upon execution by one or more processors accessible to a User Equipment (UE), to establish a scheduled communication between a UE and an Access Point, the machine executable instructions comprising: instruction(s) to receive and process a plurality of beams received from a given beamformer of the Access Point, the plurality of beams corresponding to a respective plurality of different beamwidths selectable by the given beamformer;

instruction(s) to cause transmission to the Access Point of measurement results from the processing, providing information to the Access Point for at least a subset of the plurality of beams having different beamwidths; and

instruction(s) to establish with the Access Point a scheduled wireless communication by receiving a beam generated by the beamformer, the received beam having a beamwidth selected by the Access Point depending at least in part upon the transmitted measurement results.

Example 78 may include the machine executable instructions of example 77 or some other example herein, wherein the communication is scheduled based upon a scheduling metric depending upon measurement results of a plurality of UEs located in a cell corresponding to the beamformer.

Example 79 may include a method of determining a set of beamforming bandwidth and direction combinations for a beamformer in an Access Point to serve a User Equipment (UE) distribution comprising one or more UEs located in a cell or a cell sector, the method comprising:

generating using the beamformer in the cell, a plurality of different beams corresponding to a respective plurality of different beamwidths;

receiving from the one or more UEs within range of at least one of the plurality of different beams, measurement results indicating a reception quality at the respective UE of a received one or more of the plurality of different beams;

scheduling wireless communication between the Access Point and the respective UE by selecting one of the plurality of different beamwidths depending upon the received measurement results.

Example 80 may include the method of example 79 or some other example herein, wherein the measurement results depend upon reference signals.

Example 81 may include a method of performing measurements on a User Equipment (UE) to establish a scheduled communication between the UE and an Access Point, the method comprising: receiving and processing a plurality of beams received from a given beamformer of the Access Point, the plurality of beams corresponding to a respective plurality of different beamwidths selectable by the given beamformer;

transmitting to the Access Point of measurement results from the processing, providing information to the Access Point for at least a subset of the plurality of beams having different beamwidths; and

establishing with the Access Point a scheduled wireless communication by receiving a beam generated by the beamformer, the received beam having a beamwidth selected by the Access Point depending at least in part upon the transmitted measurement results.

Example 82 may include the method of example 81 or some other example herein, wherein the measurement results comprise at least one of a received power or a received signal quality or a Channel Quality Indicator corresponding to a received reference signal

Example 83 may include means for beamforming, for use in an Access Point of a wireless communication network, the Access Point having an associated cell corresponding to a predicted geographical coverage area of one or more radio signals transmitted from the Access Point, the means for beamforming comprising:

means for generating a beam for wireless transmission in the cell, the communication signal having a beamwidth selectable from a plurality of different beamwidths; and

means for selecting one of the plurality of different beamwidths to be generated by the beamformer to serve at least one User Equipment (UE) located in the cell, wherein the selected beamwidth depends upon a target scheduling metric for the cell.

Example 84 may include the means for beamforming of example 83 or some other example herein, wherein the target scheduling metric for the cell depends upon measurement information from the UE corresponding to at least a subset of the plurality of different beamwidths.

Example 85 may include means for measurement for use in a User Equipment (UE) of a wireless communication network, the means for measurement having:

means for measuring a plurality of reference signals received at the UE, the reference signals distinguishing between beams having a plurality of different beamwidths and generated by a means for beamforming in an Access Point; and means for providing the measurements to a transmitter of the UE for transmission to the Access Point;

wherein the measurements are used by the Access Point to selects a beamwidth of a scheduled communication between the means for beamforming and the UE.

Example 86 may include the means for measurement of example 85 or some other example herein, wherein the reference signals are Channel State Information reference signals.

Example 87 may include a machine readable medium comprising code, when executed, to cause a machine to perform the method of any one of examples 79 to 82, or some other example herein.

The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various example embodiments of the invention.