AT THE UE

CROSS-REFERENCE TO RELATED APPLICATION

[0001] The present Application for Patent claims priority to Indian Provisional

Application No. 201641029792 entitled "TECHNIQUES FOR ENB MITIGATION OF FALSE TPC DETECTION AT THE UE" filed August 31, 2016, which is assigned to the assignee hereof and hereby expressly incorporated by reference in its entirety herein.

BACKGROUND

Field

[0002] The present disclosure relates generally to communication systems, and more particularly, to power control by a base station.

Background

[0003] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0004] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP). LTE is designed to support mobile broadband access through improved spectral efficiency, lowered costs, and improved services using OFDMA on the downlink, SC-FDMA on the uplink, and multiple-input multiple-output (MIMO) antenna technology. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

In LTE, the eNB sends transmission power control (TPC) commands to the UE on the physical downlink control channel (PDCCH) using various downlink control information (DCI) formats. It is possible, due to limited cyclic redundancy check (CRC) bits, that the UE incorrectly detects one or more DCI including a TPC command. That is, the UE detects a DCI when the eNB did not send the DCI. For example, the UE may occasionally detect random noise that coincidentally satisfies a CRC, leading to the noise being interpreted as a DCI, and the UE implementing a random TPC command. In existing LTE systems, a false TPC command may be detected every 10-100 seconds, for example. Because the false detection occurs at the UE, the eNB power control for the UE may become mismatched with the UE power control. That is, the UE power control function may diverge from the eNB power control function.

In view of the foregoing, there is a need for improved techniques for power control.

SUMMARY

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

In an aspect, the divergence of power control functions may be due to a UE falsely detecting a DCI. The DCI may include only 16 cyclic redundancy check (CRC) check bits. Although the check bits ensure that the vast majority of DCI transmissions are correctly detected and that random noise is not incorrectly detected as a DCI transmission, there is a small probability, e.g., 0.01% to 0.001%, that a UE falsely detects a DCI transmission. Some DCI formats allow for TPC commands that increase the transmit power by more than one step. This ability, however, also biases the error due to false TPC detections in the positive direction. Accordingly, as the UE remains in a connected mode and occasionally falsely detects TPC commands, the UE may begin to increase its transmit power above the level that was instructed by the base station. This divergence between the base station instructed transmit power and the UE interpreted transmit power leads to inefficiencies in power control. For example, the UE may transmit with a higher power than necessary and thereby interfere with transmissions from other UEs.

In an aspect, a base station such as an eNB may be configured to detect a divergence in the UE power control function from the base station power control function. The base station may then reset the UE power control function to realign the UE power control function with the base station power control function. The eNB may estimate the UE power control function based on information available at the eNB without the UE reporting the actual power control function value. In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided.

The method includes estimating, by a base station, a difference between an accumulated value of transmit power control commands detected by the UE including false detections and an accumulated value of transmit power control commands sent by the base station to the UE. The method also includes resetting, by the base station, a power control function of the UE in response to the difference satisfying a threshold value.

In an aspect, the apparatus includes a transmitter that transmits TPC commands to a UE. The apparatus includes a memory that stores an accumulated value of the TPC commands sent to the UE. The apparatus includes at least one processor coupled to the transmitter and the memory. The processor is configured to estimate a difference between an accumulated value of TPC commands detected by the UE including false detections and the accumulated value stored in the memory. The processor is configured to reset, by the base station, a power control function of the UE in response to the difference satisfying a threshold value.

In an aspect, a base station includes means for estimating, by a base station, a difference between an accumulated value of transmit power control commands detected by the UE including false detections and an accumulated value of transmit power control commands sent by the base station to the UE. The base station includes means for resetting, by the base station, a power control function of the UE in response to the difference satisfying a threshold value. [0013] In an aspect, the computer-readable medium stores computer-executable code to estimate, at a base station, a difference between an accumulated value of transmit power control commands detected by the UE including false detections and an accumulated value of transmit power control commands sent by the base station to the UE. The computer-readable medium stores computer-executable code to reset, from the base station, a power control function of the UE in response to the difference satisfying a threshold value.

[0014] To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network.

[0016] FIGs. 2A, 2B, 2C, and 2D are diagrams illustrating LTE examples of a DL frame structure, DL channels within the DL frame structure, an UL frame structure, and UL channels within the UL frame structure, respectively.

[0017] FIG. 3 is a diagram illustrating an example of an evolved Node B (eNB) and user equipment (UE) in an access network.

[0018] FIG. 4 is a diagram showing a UE in communication with a base station according to an example embodiment.

[0019] FIG. 5 is a message diagram illustrating messages between a UE and base station resulting in a divergence in power control functions.

[0020] FIG. 6 is a flowchart of an exemplary method of power control for wireless communications.

[0021] FIG. 7 is a flowchart of an exemplary method of estimating a UE power control function at a base station.

[0022] FIG. 8 is a flowchart of another exemplary method of estimating a UE power control function at a base station. [0023] FIG. 9 is a conceptual data flow diagram illustrating the data flow between different means/components in an exemplary apparatus.

[0024] FIG. 10 is a diagram illustrating an example of a hardware implementation for an apparatus employing a processing system.

DETAILED DESCRIPTION

[0025] The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

[0026] Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

[0027] By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a "processing system" that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on a chip (SoC), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

[0028] Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer- readable media can comprise a random-access memory (RAM), a read-only memory (ROM), an electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the aforementioned types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.

[0029] FIG. 1 is a diagram illustrating an example of a wireless communications system

100 including an access network. The wireless communications system 100 (also referred to as a wireless wide area network (WW AN)) includes base stations 102, UEs 104, and an Evolved Packet Core (EPC) 160. The base stations 102 may include macro cells (high power cellular base station) and/or small cells (low power cellular base station). The macro cells include eNBs. The small cells include femtocells, picocells, and microcells.

[0030] The base stations 102 (collectively referred to as Evolved Universal Mobile

Telecommunications System (UMTS) Terrestrial Radio Access Network (E- UTRAN)) interface with the EPC 160 through backhaul links 132 (e.g., S I interface). In addition to other functions, the base stations 102 may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), subscriber and equipment trace, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 may communicate directly or indirectly (e.g., through the EPC 160) with each other over backhaul links 134 (e.g., X2 interface). The backhaul links 134 may be wired or wireless.

[0031] The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the small cell 102' may have a coverage area 110' that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cell and macro cells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG). The communication links 120 between the base stations 102 and the UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use MIMO antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations 102 / UEs 104 may use spectrum up to 7 MHz (e.g., 5, 10, 15, 20 MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL). The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell).

[0032] The wireless communications system 100 may further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154 in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs 152 / AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available. [0033] The small cell 102' may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102' may employ LTE and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP 150. The small cell 102', employing LTE in an unlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network. LTE in an unlicensed spectrum may be referred to as LTE-unlicensed (LTE-U), licensed assisted access (LAA), or MuLTEfire.

[0034] The EPC 160 may include a Mobility Management Entity (MME) 162, other

MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176. The IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), a PS Streaming Service (PSS), and/or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start stop) and for collecting eMBMS related charging information.

[0035] The base station 102 may also be referred to as a Node B, an evolved Node B

(eNB), an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), or some other suitable terminology. An eNB 102 provides an access point to the EPC 160 for a UE 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, a smart device, a wearable device, or any other similar functioning device. The UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

[0036] In an aspect, a base station 102 performs power control over one or more connected UEs 104. For example, the base station 102 may receive uplink transmissions from the UE 104 and determine a signal quality such as a signal-to- noise plus interference ratio (SINR) of the uplink transmissions. The base station 102 may then determine whether to adjust the transmission power of the UE 104 based on the signal quality. The base station 102 may transmit a transmission power control (TPC) command indicating whether the UE 104 should increase the transmit power, decrease the transmit power, or keep the transmit power the same. In an LTE system, the TPC commands may be provided in downlink control information (DCI) transmitted on a physical downlink common control channel (PDCCH).

[0037] In an aspect, the DCI may include only 16 cyclic redundancy check (CRC) check bits. Although the check bits ensure that the vast majority of DCI transmissions are correctly detected and that random noise is not incorrectly detected as a DCI transmission, there is a small probability that a UE 104 falsely detects a DCI transmission. For example, false detection probability rates for UEs 104 are approximately 0.01% - 0.001%. Based on the transmission rates for LTE, this false detection probability may result in a false TPC detection approximately once every 10-100 seconds. Some DCI formats allow for TPC commands that increase the transmit power by more than one step. For example TPC values in DCI format 0 and DCI format 3 are selected from the set {-1, 0, 1, 3}. The value of 3 allows the base station 102 to quickly adjust the transmit power of the UE 104 when the base station 102 cannot correctly receive the uplink transmissions. The possibility of the 3 value, however, also biases the error due to false TPC detections in the positive direction. Accordingly, as the UE 104 remains in a connected mode and occasionally falsely detects TPC commands, the UE 104 may begin to increase its transmit power above the level that was instructed by the base station. This divergence between the base station 102 instructed transmit power and the UE 104 interpreted transmit power leads to inefficiencies in power control. For example, the UE 104 may transmit with a higher power than necessary and thereby interfere with transmissions from other UEs.

[0038] Referring again to FIG. 1, in certain aspects, the eNB 102 may be configured to detect a divergence in the UE power control function from the base station power control function. The base station 102 may then reset the UE power control function to realign the UE power control function with the base station power control function. In an aspect, the base station 102 includes a power control component 190. According to the present aspects, the base station 102 may include one or more processors that may operate in combination with the power control component 190 to detect a divergence in the UE power control function and reset the UE power control function according to aspects described in this disclosure. In an aspect, the term "component" as used herein may be one of the parts that make up a system, may be hardware, firmware, and/or software, and may be divided into other components. For example, the power control component 190 may be one of the parts that make up the eNB 102, may be hardware, firmware, and/or software, and may be divided into other components such as a UE estimation component 192 and a UE reset component 194. The power control component 190 may be communicatively coupled to a transceiver, which may include a receiver for receiving and processing RF signals and a transmitter for processing and transmitting RF signals. The power control component 190 may include the UE estimation component 192 for estimating a UE power control function and the UE reset component 194 for resetting the UE power control function as described in further detail with respect to FIG. 4.

[0039] FIG. 2A is a diagram 200 illustrating an example of a DL frame structure in

LTE. FIG. 2B is a diagram 230 illustrating an example of channels within the DL frame structure in LTE. FIG. 2C is a diagram 250 illustrating an example of an UL frame structure in LTE. FIG. 2D is a diagram 280 illustrating an example of channels within the UL frame structure in LTE. Other wireless communication technologies may have a different frame structure and/or different channels. In LTE, a frame (10 ms) may be divided into 10 equally sized subframes. Each subframe may include two consecutive time slots. A resource grid may be used to represent the two time slots, each time slot including one or more time concurrent resource blocks (RBs) (also referred to as physical RBs (PRBs)). The resource grid is divided into multiple resource elements (REs). In LTE, for a normal cyclic prefix, an RB contains 12 consecutive subcarriers in the frequency domain and 7 consecutive symbols (for DL, OFDM symbols; for UL, SC-FDMA symbols) in the time domain, for a total of 84 REs. For an extended cyclic prefix, an RB contains 12 consecutive subcarriers in the frequency domain and 6 consecutive symbols in the time domain, for a total of 72 REs. The number of bits carried by each RE depends on the modulation scheme.

As illustrated in FIG. 2A, some of the REs carry DL reference (pilot) signals (DL-RS) for channel estimation at the UE. The DL-RS may include cell-specific reference signals (CRS) (also sometimes called common RS), UE-specific reference signals (UE-RS), and channel state information reference signals (CSI-RS). FIG. 2A illustrates CRS for antenna ports 0, 1, 2, and 3 (indicated as Ro, Ri, R2, and R3, respectively), UE-RS for antenna port 5 (indicated as R5), and CSI-RS for antenna port 15 (indicated as R). FIG. 2B illustrates an example of various channels within a DL subframe of a frame. The physical control format indicator channel (PCFICH) is within symbol 0 of slot 0, and carries a control format indicator (CFI) that indicates whether the physical downlink control channel (PDCCH) occupies 1, 2, or 3 symbols (FIG. 2B illustrates a PDCCH that occupies 3 symbols). The PDCCH carries downlink control information (DCI) within one or more control channel elements (CCEs), each CCE including nine RE groups (REGs), each REG including four consecutive REs in an OFDM symbol. The DCI may be transmitted using various formats and may include one or more TPC commands. The TPC commands may indicate a change in the transmit power to be implemented by the UE for transmitting the physical uplink shared channel (PUSCH). A UE may be configured with a UE-specific enhanced PDCCH (ePDCCH) that may also carry DCI. The ePDCCH may have 2, 4, or 8 RB pairs (FIG. 2B shows two RB pairs, each subset including one RB pair). The physical hybrid automatic repeat request (ARQ) (HARQ) indicator channel (PHICH) is also within symbol 0 of slot 0 and carries the HARQ indicator (HI) that indicates HARQ acknowledgement (ACK) / negative ACK (NACK) feedback based on the PUSCH. The primary synchronization channel (PSCH) is within symbol 6 of slot 0 within subframes 0 and 5 of a frame, and carries a primary synchronization signal (PSS) that is used by a UE to determine subframe timing and a physical layer identity. The secondary synchronization channel (SSCH) is within symbol 5 of slot 0 within subframes 0 and 5 of a frame, and carries a secondary synchronization signal (SSS) that is used by a UE to determine a physical layer cell identity group number. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI). Based on the PCI, the UE can determine the locations of the aforementioned DL-RS. The physical broadcast channel (PBCH) is within symbols 0, 1, 2, 3 of slot 1 of subframe 0 of a frame, and carries a master information block (MIB). The MIB provides a number of RBs in the DL system bandwidth, a PHICH configuration, and a system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs), and paging messages.

[0041] As illustrated in FIG. 2C, some of the REs carry demodulation reference signals

(DM-RS) for channel estimation at the eNB. The UE may additionally transmit sounding reference signals (SRS) in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by an eNB for channel quality estimation to enable frequency- dependent scheduling on the UL. FIG. 2D illustrates an example of various channels within an UL subframe of a frame. A physical random access channel (PRACH) may be within one or more subframes within a frame based on the PRACH configuration. The PRACH may include six consecutive RB pairs within a subframe. The PRACH allows the UE to perform initial system access and achieve UL synchronization. A physical uplink control channel (PUCCH) may be located on edges of the UL system bandwidth. The PUCCH carries uplink control information (UCI), such as scheduling requests, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and HARQ ACK/NACK feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and/or UCI.

[0042] FIG. 3 is a block diagram of an eNB 310 in communication with a UE 350 in an access network. The eNB 310 may include a power control component 190 for controlling the transmit power of the UE 350. In the DL, IP packets from the EPC 160 may be provided to a controller/processor 375. The controller/processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor 375 provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression / decompression, security (ciphering, deciphering, integrity protection, integrity verification), and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization. The power control component 190 may use the RRC layer UE measurement reporting for determining a pathloss between the UE 350 and the eNB 310.

The transmit (TX) processor 316 and the receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor 316 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK), quadrature phase-shift keying (QPSK), M-phase-shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate may be derived from a reference signal and/or channel condition feedback transmitted by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318TX. Each transmitter 318TX may modulate an RF carrier with a respective spatial stream for transmission.

[0044] At the UE 350, each receiver 354RX receives a signal through its respective antenna 352. Each receiver 354RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for the UE 350. If multiple spatial streams are destined for the UE 350, they may be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the eNB 310. These soft decisions may be based on channel estimates computed by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the eNB 310 on the physical channel. The data and control signals are then provided to the controller/processor 359, which implements layer 3 and layer 2 functionality.

[0045] The controller/processor 359 can be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer- readable medium. In the UL, the controller/processor 359 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller/processor 359 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

[0046] Similar to the functionality described in connection with the DL transmission by the eNB 310, the controller/processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression / decompression, and security (ciphering, deciphering, integrity protection, integrity verification); RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

[0047] Channel estimates derived by a channel estimator 358 from a reference signal or feedback transmitted by the eNB 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antenna 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a respective spatial stream for transmission.

[0048] The UL transmission is processed at the eNB 310 in a manner similar to that described in connection with the receiver function at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370. The power control component 190 may use the RRC layer UE measurement reporting for determining a pathloss between the UE 350 and the eNB 310. The power control component 190 may also receive physical layer measurements of uplink channels (e.g, the PRACH). The power control component 190 may transmit TPC commands and/or reset commands via the controller/processor 375 and TX processor 316.

[0049] The controller/processor 375 can be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer- readable medium. In the UL, the controller/processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 350. IP packets from the controller/processor 375 may be provided to the EPC 160. The controller/processor 375 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

[0050] FIG. 4 illustrates a simplified communication system 400 including the eNB 102 in communication with the UE 104. The eNB 102 may transmit downlink transmissions 402 to the UE 104. The UE 104 may transmit uplink transmissions 404 to the eNB 102. The eNB 102 may include the power control component 190 for controlling the power with which the UE 104 transmits the uplink transmissions 404. The eNB 102 may transmit TPC commands and track the accumulated TPC command values for the UE 104 as F _e NB 426. The UE 104 may receive the transmitted TCP commands and track the accumulated TPC command values as FUE 428. FUE 428, however, may also include any TPC command values resulting from false detection of TPC commands. The power control component 190 may estimate a difference between accumulated transmit power control commands detected by the UE 104 (FUE) including false detections and accumulated transmit power control commands sent by the eNB 102 (FeNB). The power control component 190 may also reset a power control function of the UE 104 in response to the difference satisfying a threshold value.

[0051] According to the present aspects, the eNB 102 may include one or more processors 403 that may operate in combination with the power control component 190 to implement the power control aspects described in this disclosure. The power control component 190 may be communicatively coupled to a transceiver 406, which may include a receiver 432 for receiving and processing RF signals and a transmitter 434 for processing and transmitting RF signals. The processor 403 may be coupled to the transceiver 406 and a memory 430 via at least one bus 410.

[0052] The UE estimation component 192 may include hardware, firmware, and/or software code executable by processor 403 for estimating a difference between accumulated transmit power control commands detected by the UE including false detections and accumulated transmit power control commands sent by the eNB 102. In an aspect, the UE estimation component 192 may track F _e NB by accumulating the values of TPC commands sent to the UE 104. The UE estimation component 192, however, may not be able to directly track FUE because the false TPC detections are not observed at the eNB 102. Instead, the UE estimation component 192 may estimate FUE based on information available at the eNB 102.

[0053] From the perspective of the eNB 102, the transmission power of the UE may be shown in the following formula:

[0054] Tx Power = P0 + a * PL + 101ogl0(M) + FUE (1)

[0055] TxPower may be an actual transmit power used by the UE 104 for a transmission. P0 may be a configured minimum transmission power. P0 may be defined in a standard, transmitted in broadcast information from the eNB 102, and/or signaled to the UE 104. a is a configured partial pathloss compensation value, a may be selected by the eNB 102 and transmitted in broadcast information from the eNB 102 (e.g., SIB 2). PL may be a downlink path loss. M may be a number of resource blocks for the UE uplink transmission. FUE may be a total power adjustment applied by the UE 104 to the P0 value.

[0056] From the perspective of the eNB 102, the total power adjustment applied by the UE 104 may be shown in the following formula:

[0057] FUE = F(0) + F _eN B + AF (2)

[0058] F(0) may be a power ramp up value established by the UE 104 during a random access channel (RACH) procedure when connecting to the eNB 102. The eNB 102 may not have direct access to the F(0) value. The UE estimation component 192 may estimate F(0) based on received messages during a RACH procedure. F _e NB may be the accumulated value of TPC commands transmitted by the eNB 102 for the UE 104. The UE estimation component 192 may track F _e NB for a UE based on the transmitted TPC commands. AF may be an accumulative divergence between FeNB and an accumulated value of TPC commands detected by the UE 104. The UE estimation component 192 may determine FUE according to formula 1 above.

[0059] The UE estimation component 192 may include a RACH component 450 for performing random access channel procedures with the UE 104. The RACH component 450 may include hardware, firmware, and/or software code executable by processor 403 for estimating a power ramp up value of the UE 104 during the random access channel procedure. In LTE, the random access channel is used by a UE 104 with no assigned uplink resources to establish uplink communications. Using information broadcast by the eNB 102, the UE 104 initiates the RACH procedure by transmitting a specific message (MSG1) including a preamble at an initial transmit power (P0). If the UE receives no response to the MSG1, the UE increases the transmit power for a subsequent transmission of MSG1 by a power ramping step size (powerRampingStep). When the eNB 102 detects the MSG1, the RACH component 450 may transmit a random access response providing the UE 104 with information to establish a connection. In an aspect, the power ramp up value F(0) with which the UE 104 transmits the final MSG1 (in addition to P0) becomes an initial adjustment to the transmit power for the UE 104. The UE 104 adds the accumulated TPC commands (FUE) to P0 plus F(0) to determine a transmit power. [0060] In an aspect, the RACH component 450 may estimate F(0) based on the number of MSG1 detected before the eNB 102 responds. For example, the RACH component 450 may multiply the powerRampingStep by the number of steps (number of MSG1 detected minus 1) to estimate the power ramp up value F(0) for the UE 104. In another aspect, the RACH component 450 may estimate F(0) based on a received power of the latest MSG1 on the PRACH. In another aspect, the RACH component 450 may combine received power measurements for PRACH and the number of attempts to estimate an uplink path loss and estimate whether one or more initial MSG1 transmissions were not detected at the eNB 102. The RACH component 450 may then adjust an estimate of F(0).

[0061] The UE estimation component 192 may also include a measurement report (MR) component 452 for analyzing a measurement report transmitted by the UE 104. The MR component 452 may include hardware, firmware, and/or software code executable by processor 403 for receiving a measurement report from the UE. The measurement report may include, for example, a reference signal receive power (RSRP) of a reference signal transmitted by the eNB 102 as received at the UE 104. Because the eNB 102 knows the transmit power used to transmit the reference signal, the eNB 102 may determine a downlink pathloss based on the RSRP. The MR component 452 may further estimate an uplink pathloss based on the downlink pathloss and the configured partial pathloss compensation value (a). In an aspect, the MR is transmitted at a radio resource control (RRC) layer. The UE estimation component 192 may operate at a lower layer, e.g., PHY layer, so the values of the MR may be obtained from the higher layer.

[0062] The UE estimation component 192 may also include a power headroom report (PHR) component 454 for analyzing a power headroom report for the UE 104. The PHR component 454 may include hardware, firmware, and/or software code executable by processor 403 for receiving and analyzing scheduling information from a UE. The scheduling information may include a power headroom (PH). The PH indicates how much additional available power the UE 104 has for performing a transmission. Additionally, the PHR component 454 may also be configured to assign uplink resources to the UE 104 based on the scheduling information. For example, the PHR component 454 may increase the number of resource blocks assigned to the UE 104 when the UE has additional power headroom available. In any case, the PHR component 454 may know the number of resource blocks assigned to the UE. Accordingly, the PHR component 454 may determine a bandwidth factor in the transmission power for the UE.

[0063] In another aspect, the UE estimation component 192 may estimate the divergence between the accumulated TPC values at the eNB 102 and the UE 104 based on the duration of a connection and a volume of communications between the eNB 102 and the UE 104. The UE estimation component 192 may include a timer 456 and an UL volume 458. The timer 456 may be configured to track a time that a UE remains in a connected mode. The timer 456 may include hardware, firmware, and/or software code executable by processor 403 for determining a time period. For example, the timer 456 may include a memory location storing a time that the UE 104 connects to the eNB 102. The UL volume 458 may store a measurement of the uplink traffic received from the UE 104 at the eNB 102. For example, the UL volume 458 may include a memory storing a current value of the total traffic volume for a connection. The current value may be updated as the UE 104 transmits uplink transmissions 404. The UE estimation component 192 may estimate that AF satisfies a threshold value when the amount of time spent by the UE 104 in the connected mode exceeds a threshold time and the volume of traffic is less than a threshold volume. For example, the UE estimation component 192 may estimate that if 1 TPC false detection occurs every 100 seconds and approximately 1 in 4 of the false detections raises FUE by 3 while the other false detections cancel each other out, AF may have a value of approximately 9 dB after 1200 seconds. Accordingly, if the UE 104 has less than the threshold volume of traffic, the UE estimation component 192 may estimate that AF satisfies a threshold value.

[0064] The UE reset component 194 may be configured to reset the power control function FUE in response to the estimated difference satisfying a threshold value. The UE reset component 194 may include hardware, firmware, and/or software code executable by processor 403 for resetting the power control function FUE in response to the estimated difference satisfying a threshold value. In an aspect, the UE reset component 194 may compare the estimated difference to the threshold. The estimated difference may satisfy the threshold value when the value of the estimated difference exceeds the threshold value.

[0065] The UE reset component 194 may transmit one or more messages to reset the FUE The UE reset component 194 may transmit a UE specific nominal power value (PO-UE). The Po-uE value may be transmitted in an RRC message to inform the UE 104 of the new parameter. In response, the UE 104 may reset its local FUE value and begin transmitting at the new PO-UE value. In another aspect, the UE reset component 194 may transmit a RACH request to the UE. The RACH request may cause the UE 104 to initiate the RACH procedure. During the RACH procedure, the UE 104 may establish a new F(0) value and reset the local FUE value. In yet another aspect, the UE reset component 194 may transmit one or more TPC commands (e.g., TPC DOWN) without updating F _EN B. Accordingly, the UE 104 may receive the TPC commands and adjust the local FUE value relative to the F _E NB.

[0066] The receiver 432 may include hardware, firmware, and/or software code executable by a processor for receiving data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium). The receiver 432 may be, for example, a radio frequency (RF) receiver. In an aspect, the receiver 432 may receive and decode signals transmitted by the UE 104. The receiver 432 may determine a quality (e.g., SINR) of a received signal (e.g., a physical uplink shared channel (PUSCH)) for each uplink sub-frame. In an aspect, the receiver 432 may receive a periodic measurement report from the UE 104 on the PUCCH. The receiver 432 may decode the measurement report and pass the measurement report to the power control component 190

[0067] The transmitter 434 may include hardware, firmware, and/or software code executable by a processor for transmitting data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium). The transmitter 434 may be, for example, an RF transmitter. The transmitter 434 may transmit signals determined by the processor 103 and/or the power control component 190 such as, for example, a physical downlink common control channel (PDCCH).

[0068] In an aspect, the one or more processors 403 can include a modem 408 that uses one or more modem processors. The various functions related to power control component 190 may be included in modem 408 and/or processors 403 and, in an aspect, can be executed by a single processor, while in other aspects, different ones of the functions may be executed by a combination of two or more different processors. For example, in an aspect, the one or more processors 403 may include any one or any combination of a modem processor, or a baseband processor, or a digital signal processor, or a transmit processor, or a transceiver processor associated with transceiver 406. In particular, the one or more processors 403 may implement one or more sub-components included in power control component 190. [0069] Moreover, in an aspect, eNB 102 may include RF front end 440 and transceiver 406 for receiving and transmitting radio transmissions. For example, transceiver 406 may receive a packet in the PUSCH transmitted by the UE 104. eNB 102 may analyze the transmission to determine a signal quality (e.g., SINR) to use for determining power control commands for the UE 104. For example, transceiver 406 may communicate with modem 408 to provide the SINR to the power control component 190. The transceiver 406 may also transmit messages generated by power control component 190 and receive messages and forward them to power control component 190.

[0070] RF front end 440 may be coupled with one or more antennas 420 and can include one or more low-noise amplifiers (LNAs) 441 , one or more switches 442, 443, one or more filters 444, and/or one or more power amplifiers (PAs) 445 for transmitting and receiving RF signals. In an aspect, components of RF front end 440 can be coupled with transceiver 406. Transceiver 406 may be coupled with one or more modems 408 and processor 403.

[0071] In an aspect, LNA 441 can amplify a received signal at a desired output level. In an aspect, each LNA 441 may have a specified minimum and maximum gain values. In an aspect, RF front end 440 may use one or more switches 442, 443 to select a particular LNA 441 and its specified gain value based on a desired gain value for a particular application.

[0072] Further, for example, one or more PA(s) 445 may be used by RF front end 440 to amplify a signal for an RF output at a desired output power level. In an aspect, each PA 445 may have a specified minimum and maximum gain values. In an aspect, RF front end 440 may use one or more switches 443, 446 to select a particular PA 445 and its specified gain value based on a desired gain value for a particular application.

[0073] Also, for example, one or more filters 444 can be used by RF front end 440 to filter a received signal to obtain an input RF signal. Similarly, in an aspect, for example, a respective filter 444 can be used to filter an output from a respective PA 445 to produce an output signal for transmission. In an aspect, each filter 444 can be coupled with a specific LNA 441 and/or PA 445. In an aspect, RF front end 440 can use one or more switches 442, 443, 446 to select a transmit or receive path using a specified filter 444, LNA, 441 , and/or PA 445, based on a configuration as specified by transceiver 406 and/or processor 403. [0074] Transceiver 406 may be configured to transmit and receive wireless signals through antenna 420 via RF front end 440. In an aspect, transceiver 406 may be tuned to operate at specified frequencies such that eNB 102 can communicate with, for example, UE 104. In an aspect, for example, modem 408 can configure transceiver 406 to operate at a specified frequency and power level based on the UE configuration of the UE 104 and communication protocol used by modem 408.

[0075] In an aspect, modem 408 can be a multiband-multimode modem, which can process digital data and communicate with transceiver 406 such that the digital data is sent and received using transceiver 406. In an aspect, modem 408 can be multiband and be configured to support multiple frequency bands for a specific communications protocol. In an aspect, modem 408 can be multimode and be configured to support multiple operating networks and communications protocols. In an aspect, modem 408 can control one or more components of eNB 102 (e.g., RF front end 440, transceiver 406) to enable transmission and/or reception of signals from the network based on a specified modem configuration. In an aspect, the modem configuration can be based on the mode of the modem and the frequency band in use.

[0076] eNB 102 may further include memory 430, such as for storing data used herein and/or local versions of applications or power control component 190 and/or one or more of its subcomponents being executed by processor 403. Memory 430 can include any type of computer-readable medium usable by a computer or processor 403, such as random access memory (RAM), read only memory (ROM), tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof. In an aspect, for example, memory 430 may be a computer- readable storage medium that stores one or more computer-executable codes defining power control component 190 and/or one or more of its subcomponents, and/or data associated therewith, when eNB 102 is operating processor 403 to execute power control component 190 and/or one or more of its subcomponents. In another aspect, for example, memory 430 may be a non-transitory computer- readable storage medium.

FIG. 5 illustrates a message diagram 500 showing exemplary messages that may be transmitted between an eNB 102 and a UE 104. The messages illustrate an example of detecting diverging power control functions and the resetting the UE 104 to correct the divergence. [0078] Message 502 is a RACH MSGl transmitted by the UE 104 to initiate an uplink connection to the eNB 102. The UE 104 may transmit message 502 with a transmit power of P0. In an aspect, the transmit power P0 may be insufficient for the eNB 102 to detect the message 502. Message 504 may be a retransmission of the MSGl from UE 104 to eNB 102 with a higher transmit power. For example, the transmit power may be increased to P0 + powerRampingStep. The transmit power of message 504 may be sufficient for eNB 102 to detect, but the eNB 102 may decide not to immediately respond. Message 506 may be another retransmission of the MSGl with a higher transmit power set to P0 + 2 * powerRampingStep. Message 508 may be another retransmission of the MSGl with a higher transmit power set to P0 + 3 * powerRampingStep. Message 510 may be a MSG2 RACH response from eNB 102 to UE 104. The message 510 may include parameters for the UE 104 to establish the uplink connection. The UE 104 and eNB 102 may transmit additional RACH messages (not shown) to complete the RACH procedure. The UE 104 may set the power ramp up value F(0) to 3 * powerRampingStep based on the last transmitted MSGl.

[0079] In block 512, the eNB 102 may determine a number of RACH attempts and estimate the value of F(0). In an aspect, the eNB 102 may estimate the value of F(0) based on the number of received MSGl, which in this case may be three (3). Accordingly, the eNB 102 may estimate that two (2) power ramping steps were performed and that F(0) is 2 * powerRampingStep. This estimate may be incorrect because the eNB 102 did not detect message 502. In another aspect, the eNB 102 may measure a received power of message 508 to estimate F(0). The eNB 102, however, may not know a pathloss. In another aspect, the eNB 102 may estimate the pathloss based on received power measurements of multiple received MSGl and the known powerRampingStep size. Accordingly, the eNB 102 may be able to determine an accurate estimate of F(0).

[0080] After the UE 104 establishes an uplink connection, the eNB 102 may transmit TPC commands to the UE 104. For example, the message 514 may indicate to increase the UE transmit power by 1 dB. The eNB 102 may set the F _E NB value to +1, and the UE 104 may set the FUE value to F(0)+1. The message 516 may be another TPC command indicating to increase the UE transmit power by 3 dB. The eNB 102 may accumulate the F _E NB value to + 4, and the UE 104 may accumulate the FUE value to F(0)+4. At block 518, the UE 104 may detect a TPC command even if the eNB 102 does not transmit a TPC command. For example, random noise may satisfy the CRC check and the UE 104 may detect a random TPC value. It should be appreciated that the false detection probability may actually be relatively low and several false detections are shown for illustrative purposes. The false detection at block 518 may cause the UE 104 to accumulate the FUE value to F(0)+7, while the FeNB value remains at +4. Message 520 may be a TPC down command indicating to decrease the UE transmit power by 1 dB. The eNB 102 may accumulate the F _e NB value to + 6, and the UE 104 may accumulate the FUE value to F(0)+3. Accordingly, although the eNB 102 may lower the UE transmit power in response to the unintended increase in UE transmit power, the FeNB value is also decreased, indicating that the UE is using a lower power than the actual transmit power.

[0081] Message 522 may be a measurement report transmitted by the UE 104. The measurement report may include an RSRP value for the eNB 102. The eNB 102 may use the RSRP value to determine a downlink pathloss between the UE 104 and the eNB 102. In block 524, the UE 104 may detect a TPC command even if the eNB 102 does not transmit a TPC command. The false detection at block 524 may cause the UE 104 to accumulate the FUE value to F(0)+9, while the F _e NB value remains at +3. Although the false detection is illustrated as having a command value of +3, it is also possible to falsely detect other values. However, in an aspect, for every +1 value, there is an equally likely chance of a -1 value, so the other false detections are likely to cancel each other out and are omitted. It should be noted, however, that the disclosed techniques may also be applicable to situations where a series of false detections in the same direction result in a divergence of TPC functions.

[0082] Message 526 may be a power headroom report (PHR) transmitted by the UE 104. The PHR may be a MAC layer control element. The PHR may be transmitted periodically, or may be transmitted when the downlink pathloss changes suddenly. The PHR may include a power headroom (PH) value that indicates a relative transmission power left in the UE when transmitting PUSCH. The eNB 102 may determine the PUSCH transmit power by subtracting the PHR from a maximum UE transmit power. Accordingly, the eNB may determine the actual UE transmit power.

In block 528, the eNB 102 may estimate a difference between FUE and FeNB.. FeNB is already known at the eNB 102. In this example, F _e NB has a value of +3. FUE may be estimated based on formulas 1 and 2 above. Assuming for example, that the RSRP indicates a pathloss of 80 dB, a is 0.7, PO is -80 dBm/RB, the PH indicates a TX power of 14 dBm and the UE is assigned 50 RB, according to formula 1, FUE has a value of 21 dBm. When adjusted according to formula 2 to account for F(0), which the eNB 102 may estimate as 3*powerRampingStep = 12 dBm. The value of AF may be estimated as 6 dBm.

[0084] Message 530 may be a message that resets the FUE. For example, a RACH request may cause the UE 104 to transmit another MSG1 and reset both F(0) and FUE AS another example, the eNB 102 may set a new P0 value, causing the UE 104 to reset FUE. In a third example, the eNB 102 may transmit a TPC DOWN command to correct the FUE value without updating F _E NB.

[0085] FIG. 6 is a flowchart of an exemplary method 600 of power control for wireless communications in accordance with one or more aspects. The method 600 may be performed by a base station (e.g., the eNB 102) or the apparatus 902/902').

[0086] At 610, the method 600 may include estimating a difference between an accumulated value of transmit power control commands detected by the UE including false detections and an accumulated value of transmit power control commands sent by the base station to the UE. In an aspect, for example, the UE estimation component 192 may estimate the difference between the accumulated value of transmit power control commands detected by the UE including false detections and the accumulated value of transmit power control commands sent by the base station to the UE. The UE estimation component 192 may estimate the accumulated value of transmit power control commands detected by the UE according to method 700 (FIG. 7) and/or method 800 (FIG. 8), which are discussed in further detail below. The UE estimation component 192 may store the accumulated value of transmit power control commands sent by the base station to the UE (e.g., in memory 430). The UE estimation component 192 may estimate the difference by subtracting the accumulated value of transmit power control commands sent by the base station from the estimated accumulated value of transmit power control commands detected by the UE.

[0087] In block 620, the method 600 may include determining whether the difference satisfies a threshold value. In an aspect, for example, the power control component 190 may determine whether the difference satisfies a threshold value. For example, the power control component 190 may compare an absolute value of the difference to the threshold value. If the absolute value is greater than the threshold value, the power control component 190 may determine that the difference satisfies the threshold. In another aspect, the power control component 190 may not be concerned about negative differences and compare the actual value of the difference to the threshold. The threshold may be based upon a difference that causes a noticeable system degradation (e.g., interference to other UEs or eNBs). The threshold may be selected based on a current system load. Exemplary thresholds of 10 dB, 20 dB, 30 dB or higher may be used. If the difference satisfies the threshold, the method 600 may proceed to block 630. If the difference does not satisfy the threshold, the method 600 may return to block 610 for periodically estimating the difference.

[0088] In block 630, the method 600 includes resetting, by the base station, a power control function of the UE in response to the difference satisfying a threshold value. In an aspect, for example, the UE reset component 194 may reset the power control function of the UE in response to the difference satisfying the threshold value. For example, in block 640, resetting the power control function may include sending a new nominal transmit power parameter to the UE. The UE reset component 194 may send the new nominal transmit power parameter in an RRC reconfiguration message transmitted via the transmitter 434, RF front end 440, and antenna 420.

[0089] In another example, resetting the power control function of the UE may include, at block 650, sending a random access channel (RACH) request to the UE. The UE reset component 194 may send the RACH request to the UE via the transmitter 434, RF front end 440, and antenna 420. In block 652, the UE reset component 194 may receive at least one transmission from the UE on the RACH. For example, the UE reset component 194 may receive a MSG1 from the UE 104 via the antenna 420, RF front end 440, and receiver 432. In block 654, the UE reset component 194 may send a response to the at least one transmission on the RACH. For example, the UE reset component 194 may transmit a MSG2 via the transmitter 434, RF front end 440, and antenna 420.

[0090] As another example of resetting the power control function of the UE, in block 660, the UE reset component 194 may send a TPC down command to the UE 104 without counting the TPC down command towards the accumulated transmit power control commands sent by the base station. For example, the UE reset component 194 may transmit the TPC command via the transmitter 434, RF front end 440, and antenna 420. The UE reset component 194 may maintain the value of F _e NB. The UE 104, upon receiving the TPC down command, may decrement FUE. Accordingly, transmitting a TPC down command without counting the TPC down command toward F _e NB may be used to correct a mismatch between FUE and F _E NB. Further, because the TPC command changes the value of FUE without affecting the value of FeNB, the TPC down command may be said to reset FUE. The UE reset component 194 may transmit multiple TPC down commands to set FUE to a desired value.

FIG. 7 is a flowchart of an exemplary method 700 of estimating, by a base station, an accumulated value of transmit power control commands detected by the UE including false detections in accordance with an aspect. The method 700 may be performed by a base station (e.g., the eNB 202). The method 700 may correspond to block 610 in FIG. 6.

In block 705, the method 700 may include receiving a power headroom from the UE. In an aspect, for example, the PHR component 454 may receive a power headroom from the UE. The PHR component 454 may receive a power headroom report via the antenna 420, RF front end 440, and receiver 432. In an aspect, the power headroom report may be a MAC layer control element including a power headroom index value. The PHR component 454 may include a look up table for formula for converting the power headroom index value to a value or range of values of the UE power headroom.

In block 710, the method 700 may include determining an actual UE transmit power based on the power headroom. In an aspect, the PHR component 454 may determine the actual UE transmit power based on the power headroom. For example, the PHR component 454 may subtract the power headroom from a maximum UE transmit power to determine the actual transmit power.

In block 715, the method 700 may include determining a number of resource block allocations corresponding to the power headroom. In an aspect, for example, the PHR component 454 may determine the number of resource block allocations corresponding to the power headroom. The PHR component 454 may use the power headroom to determine the resource block allocations for the UE. The received power headroom may correspond to a previously provided resource block allocation. Accordingly the PHR component 454 may determine a number of resource blocks that the received power headroom corresponds to. In block 720, the method 700 may include receiving a measured RSRP value from the UE. In an aspect, for example, the MR component 452 may receive the measured RSRP value from the UE. For example, the RSRP value may be included in a RRC layer measurement report transmitted by the UE 104 and received at the eNB 102 via the antenna 420, RF front end 440, and receiver 432. The MR component 452 may extract the RSRP value for the eNB 102 from the measurement report.

In block 725, the method 700 may include determining downlink pathloss based on the RSRP value. In an aspect, for example, the MR component 452 may determine the downlink pathloss based on the RSRP value. For example, the RSRP value may be based on the measured signal strength of a reference signal transmitted by the eNB 102. The MR component 452 may subtract the RSRP value from the transmit power of the reference signal to determine the downlink pathloss.

In block 730, the method 700 may include adjusting the downlink pathloss using a configured partial pathloss compensation value. In an aspect, for example, the MR component 452 may adjust the downlink pathloss using the configured partial pathloss compensation value. The partial pathloss compensation value may be configured by the eNB 102. The MR component 452 may multiply the downlink pathloss by the configured partial pathloss compensation value to adjust the downlink pathloss and estimate the uplink pathloss.

In block 735, the method 700 may include estimating the accumulated transmit power control commands detected by the UE based at least in part on one or more of a nominal transmit power, the actual transmit power, the number of resource blocks, and/or the downlink pathloss. In an aspect, the UE estimation component 192 may estimate the accumulated transmit power control commands detected by the UE based at least in part on one or more of a nominal transmit power, the actual transmit power, the number of resource blocks, and/or the downlink pathloss. For example, the UE estimation component 192 may use formula 1 described above to estimate the accumulated transmit power control commands detected by the UE (FUE). In an aspect, one or more of the terms of formula 1 may be estimated, set to a constant, or removed from the estimation.

In block 740, the method 700 may include estimating a power ramp up value of the UE during a RACH procedure. In an aspect, the RACH component 450 may estimate the power ramp up value of the UE during the RACH procedure. In an aspect, the block 740 may be performed during the RACH procedure or based on values obtained during the RACH procedure. For example, the RACH component 450 may estimate the power ramp up value based on a number of MSG1 messages received from the UE 104 on the RACH channel during the RACH procedure and/or based on a receive signal power of the PRACH for the MSG1 messages.

In block 745, the method 700 may include adjusting the estimated accumulated value by the power ramp up value. In an aspect, for example, the RACH component 450 may adjust the estimated accumulated value by the power ramp up value. For example, the RACH component 450 may subtract the power ramp up value from the estimated accumulated value. In another aspect, the RACH component 450 may subtract the power ramp up value from the estimated difference between an accumulated value of transmit power control commands detected by the UE including false detections and an accumulated value of transmit power control commands sent by the base station to the UE.

FIG. 8 is a flowchart of an exemplary method 800 of estimating, by a base station, an accumulated value of transmit power control commands detected by the UE including false detections in accordance with an aspect. The method 800 may be performed by a base station (e.g., the eNB 202). The method 800 may correspond to block 610 in FIG. 6.

In block 810, the method 800 may include determining an amount of time spent by the UE in a connected mode. In an aspect, for example, the timer 456 may determine the amount of time spent by the UE in the connected mode. For example, the timer 456 may store a time when the UE entered the connected mode and subtract the stored time from the current time. As another example, the timer 456 may be a timer that measures a time from when the UE entered the connected mode.

In block 820, the method 800 may include determining a volume of uplink traffic from the UE during the time spent in the connected mode. In an aspect, for example, the UE estimation component 192 may determine the volume of uplink traffic from the UE during the time spent in the connected mode based on UL volume 458.

In block 830, the method 800 may include estimating that the difference satisfies the threshold value when the amount of time spent by the UE in the connected mode exceeds a threshold time and the volume of traffic is less than a threshold volume. In an aspect, the UE estimation component 192 may estimate that the difference satisfies the threshold value when the amount of time spent by the UE in the connected mode exceeds the threshold time and the volume of traffic is less than the threshold volume. In an aspect, the threshold time may be based on an estimated false detection probability or false detection rate. In an aspect, the threshold time is in the range of 10 minutes to 40 minutes, preferably 15 minutes to 30 minutes. The threshold volume may be selected to prevent resetting busy UEs. For example, a busy UE may receive many TPC commands such that the divergence in power control functions due to false detections may not have a significant impact.

FIG. 9 is a conceptual data flow diagram 900 illustrating the data flow between different means/components in an exemplary apparatus 902. The apparatus may be an eNB. The apparatus includes a reception component 904 that receives transmissions from a UE 950, a TPC component 906 that determines TPC commands, a MR component 908 that determines a pathloss, a RACH component 912 that performs a RACH procedure, a PHR component 914 that determines a UE transmit power, a UE estimation component 916 that estimates a UE power control function, a reset component 918 that resets the UE power control function, and a transmission component 920 that transmits transmissions to the UE 950.

The reception component 904 may receive uplink transmissions such as a measurement report and a power headroom report. The reception component 904 may also receive data transmitted by the UE on the PUSCH and the RACH. The reception component 904 may provide the measurement report to the MR component 908. The reception component 904 may provide the power headroom report to the PHR component 914. The reception component 904 may measure a received power and/or quality of the PUSCH and provide the power and/or quality to the TPC component 906. The reception component 904 may provide the RACH transmissions to the RACH component 910.

The TPC component 906 may receive the PUSCH power and/or quality. The TPC component 906 may generate TPC commands. For example, the TPC component 906 may generate TPC commands according to known power control algorithms. The TPC component 906 may provide the TPC commands to the transmission component 920.

The MR component 908 may receive a measurement report from the reception component 904. The MR component 908 may extract the RSRP from the measurement report and determine a pathloss. The pathloss may be adjusted by a configured partial pathloss compensation factor. The MR component 908 may provide the pathloss to the UE estimation component 916.

The RACH component 910 may receive the received RACH from the reception component 904. The RACH component 910 may perform a RACH procedure including sending MSG2 to the UE 950 via the transmission component 920. The RACH component 910 may also estimate the UE power ramp up, F(0), based on the received RACH. The RACH component 910 may provide F(0) to the UE estimation component 916.

The PHR component 914 may receive a power headroom report from the reception component 904. The PHR component 914 may extract a power headroom from the power headroom report and determine an actual UE transmit power based on the power headroom. The PHR component 914 may provide the actual UE transmit power to the UE estimation component 916.

The UE estimation component 916 may receive the pathloss, F(0), and transmit power. The UE estimation component 916 may estimate a UE power control function or a value of accumulated power control commands detected by the UE. The UE estimation component 916 may determine whether the estimated UE power control function or the value of the accumulated power control commands satisfies a threshold. If the threshold is satisfied, the UE estimation component 916 may send an indication to reset component 918.

Reset component 918 may receive the indication from UE estimation component 916, and in response, reset the power control function at the UE 950. For example, the reset component 918 may generate a message that causes UE 950 to reset the power control function.

The transmission component 920 may transmit messages generated by other components such as the MSG2, TPC commands, and the reset message. The transmission component 920 may transmit the messages to the UE 950.

The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowcharts of FIGs. 6-8. As such, each block in the aforementioned flowcharts of FIGs. 6-8 may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

[00115] FIG. 10 is a diagram 1000 illustrating an example of a hardware implementation for an apparatus 902' employing a processing system 1014. The processing system 1014 may be implemented with a bus architecture, represented generally by the bus 1024. The bus 1024 may include any number of interconnecting buses and bridges depending on the specific application of the processing system 1014 and the overall design constraints. The bus 1024 links together various circuits including one or more processors and/or hardware components, represented by the processor 1004, the components 906, 908, 910, 914, 916, and the computer-readable medium / memory 1006. The bus 1024 may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

[00116] The processing system 1014 may be coupled to a transceiver 1010. The transceiver 1010 is coupled to one or more antennas 1020. The transceiver 1010 provides a means for communicating with various other apparatus over a transmission medium. The transceiver 1010 receives a signal from the one or more antennas 1020, extracts information from the received signal, and provides the extracted information to the processing system 1014, specifically the reception component 904. In addition, the transceiver 1010 receives information from the processing system 1014, specifically the transmission component 920, and based on the received information, generates a signal to be applied to the one or more antennas 1020. The processing system 1014 includes a processor 1004 coupled to a computer-readable medium / memory 1006. The processor 1004 is responsible for general processing, including the execution of software stored on the computer- readable medium / memory 1006. The software, when executed by the processor 1004, causes the processing system 1014 to perform the various functions described supra for any particular apparatus. The computer-readable medium / memory 1006 may also be used for storing data that is manipulated by the processor 1004 when executing software. The processing system 1014 further includes at least one of the components 904, 906, 908, 910, 914, 916, 918, 920. The components may be software components running in the processor 1004, resident/stored in the computer readable medium / memory 1006, one or more hardware components coupled to the processor 1004, or some combination thereof. The processing system 1014 may be a component of the eNB 310 and may include the memory 376 and/or at least one of the TX processor 316, the RX processor 370, and the controller/processor 375.

[00117] In one configuration, the apparatus 902/902' for wireless communication includes means for means for estimating, by a base station, a difference between an accumulated value of transmit power control commands detected by the UE including false detections and an accumulated value of transmit power control commands sent by the base station to the UE; and means for resetting, by the base station, a power control function of the UE in response to the difference satisfying a threshold value. The aforementioned means may be one or more of the aforementioned components of the apparatus 902 and/or the processing system 1014 of the apparatus 902' configured to perform the functions recited by the aforementioned means. As described supra, the processing system 1014 may include the TX Processor 316, the RX Processor 370, and the controller/processor 375. As such, in one configuration, the aforementioned means may be the TX Processor 316, the RX Processor 370, and the controller/processor 375 configured to perform the functions recited by the aforementioned means.

[00118] It is understood that the specific order or hierarchy of blocks in the processes / flowcharts disclosed is an illustration of exemplary approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes / flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

[00119] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more." The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term "some" refers to one or more. Combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words "module," "mechanism," "element," "device," and the like may not be a substitute for the word "means." As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase "means for."