# Xiaodong Wang, New York US

## Xiaodong Wang, New York, NY US

Patent application number | Description | Published |
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20080219145 | Method for Scheduling Heterogeneous Traffic in B3G/4G Cellular Networks with Multiple Channels - A method includes tracking average user throughput, packet delay and jitter for every user that is serviced in an OFDM cellular system; using feedback to determine a potential schedule set responsive to user requirements for data and voice traffic responsive to minimum rate guarantee for data flows, and maximum tolerable delay and jitter guarantees for voice flows; with multiple flows for each user, first determining contending flow for each user responsive to aggregate rate feedback; obtaining search space for the user requirements of rate, delay and jitter responsive to corresponding optimizing strategies; determining individual rate, delay and jitter related schedules providing maximum incremental or marginal utility; and calculating final schedule of users on channels providing maximum incremental or marginal utility among parameter specific schedules form the determining step. | 09-11-2008 |

20080225763 | Group MMSE-DFD with Rate (SINR) Feedback and Without Pre-Determined Decoding Order for Reception on a Cellular Downlink - In accordance with the invention, a method includes the steps of: i) initializing with channel matrix estimates and inner codes of all co-channel transmitter sources in a wireless network, modulation and coding schemes of all sources not of interest; ii) converting each channel matrix estimate into an effective channel matrix responsive to the inner code of the corresponding transmitter source; iii) selecting iteratively from a first set of transmitter sources transmitting at fixed rates, a transmitter source which maximizes a first metric; iv) computing iteratively a filter for the transmitter source which maximizes the first metric; v) selecting iteratively from a second set of transmitter sources of interest, a transmitter source which maximizes a second metric; vi) computing iteratively a rate and a filter for the transmitter source which maximizes the second metric; and vii) obtaining an ordered set of indices of all transmitter sources that will be decoded along with their corresponding filters, and feedback rates for all transmitter sources of interest. | 09-18-2008 |

20080225774 | OPTIMAL RESOURCE ALLOCATION IN A MULTI-HOP OFDMA WIRELESS NETWORK WITH COOPERATIVE RELAYING - An optimal resource allocation strategy for OFDMA multi-hop wireless networks is disclosed. The system allocates one or more resources in a multi-hop network by solving one or more higher-layer sub-problem; solving one or more physical layer and media access control (PHY/MAC) layer sub-problems per tone per time slot with one of cooperative relaying of radio signals or spatial reusing of radio spectrum; updating prices; and allocating radio resources based on the PHY/MAC layer sub-problems. | 09-18-2008 |

20080225781 | Group MMSE-DFD with Order and Filter Computation for Reception on a Cellular Downlink - A method for decoding in a wireless downlink channel, where all dominant transmitting sources use inner codes from a particular set, including the steps of: estimating a channel matrix seen from each dominant transmitter source in response to a pilot or preamble signal transmitted by each such source; converting each estimated channel matrix into an effective channel matrix responsive to the inner code of the corresponding transmitting source; obtaining the received observations in a linear equivalent form whose output is an equivalent of the received observations and in which the effective channel matrix corresponding to each dominant transmitting source inherits the structure of its inner code; i) determining an order for processing each of the transmitting sources; ii) computing a filter for each transmitting source that will be decoded; iii) demodulating and decoding each transmitting source responsive to the determined order from step i) assuming perfect cancellation of signals of preceding or previously decoded transmitting sources; and iv) re-encoding the decoded message of each transmitting source, except the source decoded last, responsive to the modulation and coding scheme employed by the source and the corresponding effective channel matrix and subtracting it from the received observations in the equivalent linear form. | 09-18-2008 |

20080225974 | Max-Log Receiver for Multiple-Input Multiple-Output (MIMO) Systems - A method includes the steps of i) listing out all possibilities for a first symbol of a two stream signal; ii) determining a second symbol of the two stream signal for each of the first symbol listed out, iii) evaluating a metric for each of the first symbol and second symbol pair, iv) listing out all possibilities for second symbol, v) determining a first symbol for each choice of the second symbol listed out, vi) evaluating a metric for each of the second symbol and first symbol pair, vii) determining an exact maximum log likelihood ratio for all bits using the metrics, and viii) decoding codeword(s) in the two stream signal using the determined exact maximum log likelihood ratio for all bits. | 09-18-2008 |

20080225979 | Group MMSE-DFD with Rate (SINR) Feedback and Pre-Determined Decoding Order for Reception on a Cellular Downlink - A method for decoding and rate assignment in a wireless channel, where all dominant transmitter sources use inner codes from a particular set, comprising the steps of: i) estimating channel matrices seen from all dominant transmitter sources in response to a pilot or preamble signal transmitted by each such source; ii) converting each estimated channel matrix into an effective channel matrix responsive to the inner code of the corresponding transmitter source; iii) obtaining the received observations in a linear equivalent form (linear model) whose output is an equivalent of the received observations and in which the effective channel matrix corresponding to each dominant transmitter source inherits the structure of its inner code; iv) processing the transmitter sources according to the specified (or pre-determined) order of decoding; v) for each transmitter source, assuming perfect cancellation of signals of preceding transmitter sources; vi) computing a signal-to-interference-noise-ratio SINR responsive to the effective channel matrix of the transmitter source and the covariance matrix of the noise plus signals from remaining transmitter sources; and vii) feeding back all computed SINRs to respective transmitter sources. | 09-18-2008 |

20080227397 | Group LMMSE Demodulation Using Noise and Interference Covariance Matrix for Reception on a Cellular Downlink - A method for filtering in a wireless downlink channel, where all dominant transmitting sources use inner codes from a particular set, includes the steps of estimating a channel matrix seen from a desired transmitter source in response to a pilot or preamble signal; converting the estimated channel matrix into an effective channel matrix responsive to the inner code of the desired transmitting source; estimating a covariance matrix of noise plus interference in a linear model whose output is an equivalent of the received observations and in which the effective channel matrix corresponding to each dominant transmitting source inherits the structure of its inner code; computing a signal-to-noise-interference-ratio SINR responsive to the covariance matrix and the effective channel matrix corresponding to the desired source; and feeding back the computed SINR to the transmitter source. | 09-18-2008 |

20080232501 | STATIC AND DIFFERENTIAL PRECODING CODEBOOK FOR MIMO SYSTEMS - Systems and methods are disclosed to generate a codebook for channel state information by generating a random codebook; partitioning channel state information into a set of nearest neighbors for each codebook entry based on a distance metric; and updating the codebook by finding a centroid for each partition. | 09-25-2008 |

20080285665 | Methods and Systems for Providing Feedback for Beamforming - Methods and systems for providing feedback for beamforming are provided. In some embodiments, methods for providing feedback for beamforming are provided, the methods comprising: initializing a weighting vector; determining a perturbation vector; determining a plurality of weighting vectors to be applied to data based on the weighting vector and the perturbation vector; applying the plurality of weighting vectors to the data to provide weighted data; transmitting the weighted data to a receiver; receiving from the receiver a feedback signal based on at least one of the plurality of weighting vectors; and updating the plurality of weighting vectors based on the feedback signal. | 11-20-2008 |

20080285666 | Methods and Systems for Digital Wireless Communication - Methods and systems for digital wireless communication are provided. | 11-20-2008 |

20080298486 | MULTI-CELL INTERFERENCE MITIGATION VIA COORDINATED SCHEDULING AND POWER ALLOCATION IN DOWNLINK ODMA NETWORKS - A multi-cell Orthogonal Frequency-Division Multiple Access (OFDMA) based wireless system and method with full spectral reuse co-channel interference mitigation via base station coordination in a downlink channel includes a plurality of base stations configured to handle communications with mobile units. A central controller is configured to mitigate interference between base stations via jointly optimizing coordinated scheduling and power allocation in accordance with a sub-optimal iterative solution. Five methods provide the solution, which include: 1) Improved Iterative Water-Filling (I-IWF); 2) Iterative Spectrum Balancing (ISB); 3) Successive Convex Approximation for Low-complexity (SCALE); 4) Opportunistic Base Station Selection (OBSS) and 5) Per-tone binary power control (PT-BPC). | 12-04-2008 |

20090003259 | SYSTEM AND METHOD FOR SCHEDULING IN RELAY-ASSISTED WIRELESS NETWORKS - A scheduling system and method for use with relay-assisted wireless networks includes accessing feedback from mobile stations in a network and arranging users associated with a relay station in a list in accordance with marginal utilities. A determination of whether the users in the list can be eliminated from feedback overhead by testing conditions for feedback reduction is made. A diversity schedule is generated by employing a weighted bipartite graph with relay channels and access channels and performing a matching method. A transmission schedule is generated for channel usage in accordance with multi-user and channel diversity for mobile users and spatial reuse of channels across relay and access hops by incorporating rate feedback and interference for the mobile stations and the relay stations based upon the matching method applied to a new weighted graph which accounts for traffic loads and fairness as well. | 01-01-2009 |

20090083609 | EFFICIENT LOW COMPLEXITY HIGH THROUGHPUT LDPC DECODING METHOD AND OPTIMIZATION - A decoder and method for iteratively decoding of low-density parity check codes (LDPC) includes, in a code graph, performing check node decoding by determining messages from check nodes to variable nodes. In the code graph, variable node decoding is performed by determining messages from the variable nodes to the check nodes. The variable node decoding is independent from degree information regarding the variable nodes. Decoded results are output. | 03-26-2009 |

20090129328 | Wireless Communication Rate Allocation on a Gaussian Interference Channel - There is provided a method for allocating transmission rates in a wireless network, includes the steps of associating transmitters with corresponding receivers for communicating on an interference channel in the wireless network, and allocating a transmission rate to each transmitter for decoding by its corresponding receiver, the allocated transmission rate being equal to a desired rate of a fixed user rate and being no less than a minimum rate of a variable user rate. The step of allocating can include a sequential allocation that meets the minimum rate requirement of all users and assigns excess rates to variable rate users in a sequential fashion according to specified priorities. The step of allocating can include a parallel symmetric rate allocation when all variable rate users have the same priority and that meets minimum rate requirements of all users and is symmetric fair. The step of allocating can include a parallel iterative rate allocation with the sequence of rate allocations obtained for each user being non-decreasing and a rate allocation vector obtained after each iteration meets minimum rate requirements for all users and is max-min fair when all variable rate users have the same priority. | 05-21-2009 |

20090210757 | Anti-Jamming Piecewise Coding Method for Parallel Inference Channels - A method for encoding includes encoding K blocks of information for transmission on N subchannels responsive to a number of redundant blocks M according to one of i) employing a single parity check code when the number of redundant blocks M is about 1; ii) employing a code exhibited by a code graph having one third of variable nodes are connected to one of the check nodes, another one third of variable nodes is connected to the other check node and the remaining one third of variable nodes is connected to both check nodes, when the number of redundant blocks M is 2; iii) employing a first process for determining a code for the K blocks of information, when the number of redundant blocks M is about 3 together with K blocks of information less than about 150 or the number of redundant blocks M is about 4 together with K blocks of information less than about 20; and iv) employing a second process for determining a code for the K blocks of information with redundant block M values other than for steps i), ii) and iii). | 08-20-2009 |

20090231028 | TWO-STAGE LOW-COMPLEXITY MAX-LOG BIT-LEVEL LLR CALCULATOR AND METHOD - A demodulator and demodulation method includes a bit/symbol hard demodulator configured to obtain hard bit or symbol information from a received signal. At least one lookup table is configured to reference coefficients for computation of log-likelihood ratios (LLRs) from the hard bit or symbol information. A log-likelihood ratio calculation module is configured to compute bit-level LLRs from the coefficients and the received signal. | 09-17-2009 |

20090232074 | AUCTION BASED RESOURCE ALLOCATION IN WIRELESS SYSTEMS - Systems and methods to assign one or more resources in a multi-user cellular Orthogonal Frequency-Division Multiple Access (OFDMA) uplink includes specifying a resource allocation problem for one or more resources; converting the resource allocation problem into an assignment problem; solving the assignment problem through an auction; and allocating one or more resources to cellular users to maximize a system utility. | 09-17-2009 |

20090262872 | RECEIVER WITH PREFILTERING FOR DISCRETE FOURIER TRANSFORM-SPREAD-ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING (DFT-S-OFDM) BASED SYSTEMS - A receiver for discrete Fourier transform-spread-orthogonal frequency division multiplexing (DFT-S-OFDM) based systems, including a prefilter for received signal codeword(s); and a log-likelihood ratio LLR module responsive to the prefilter; wherein the prefilter includes a pairing and whitening module that based on channel estimates and data rate enables the LLR module to perform either a Serial-In-Serial-Out (SISO) based log likelihood ratio processing of an output from the paring and whitening module or a two-symbol max-log soft output demodulator (MLSD) based log likelihood ratio processing of an output from the pairing and whitening module. | 10-22-2009 |

20090270028 | Rateless Coding for Multiuser Interference Relay Channel - An interference relay channel (IRC) utilizes a single relay to assist communications between multiple source-destination links under the half-duplex (HD) constraint. It is assumed that each source has an independent message and its transmitted signal may cause interference at the other destinations. It is also assumed that each node only estimates its backward channels and has no knowledge of its forward channels as well as the other links. The role of the relay is to generate signals to cooperate with the intended signal and mitigate the interference at all destinations. | 10-29-2009 |

20090274225 | MULTI-RESOLUTION PRECODING CODEBOOK - Systems and methods are for generating a codebook by: generating a multi-resolution codebook by selecting a common precoder index from a low resolution codebook for a group of adjacent resource blocks (RB)s and for each RB within the group, selecting a high-resolution codebook to fine-tune each RB precoder; and generating feedback for the multi-resolution codebook by quantizing channel state variations. | 11-05-2009 |

20090276679 | Hybrid ARQ Transmission Method With Channel State Information - A method for decoding of multiple wireless signals by a chase combining hybrid-automatic-repeat-request CC-HARQ receiver includes demodulating wireless signals received from respective mobile sources using an effective channel matrix and decision statistics; updating log-likelihood-ratios LLRs and decoding the received codewords using the corresponding updated LLRs; determining set of correctly decoded codewords using a cyclic redundancy check; updating the effective channel matrix and decision statistics responsive to the step of determining; and resetting the effective channel matrix and decision statistics in the event that the number of decoding errors for a codeword exceeds its maximum limit after storing the updated LLRs of all remaining erroneously decoded codewords for which the number of decoding errors is below the respective maximum limit. | 11-05-2009 |

20090282309 | COGNITIVE RADIO, ANTI-JAMMING CODING RETRANSMISSION METHODS AND SYSTEMS - Implementations of the present principles include methods and systems for retransmitting un-recovered information within a cognitive radio, anti-jamming system. In accordance with aspects of the present principles, encoding schemes may be optimized for retransmission by utilizing a jamming rate and a number of un-recovered packets to minimize packet loss and thereby enhance throughput. In addition, rateless encoding features may be employed to re-encode un-recovered portions of an information sequence for efficient retransmission. | 11-12-2009 |

20090296650 | COORDINATED LINEAR BEAMFORMING IN DOWNLINK MULTI-CELL WIRELESS NETWORKS - System and methods are disclosed for optimizing wireless communication for a plurality of mobile wireless devices. The system uses beamforming vectors or precoders having a structure optimal with respect to the weighted sum rate in a multi-cell orthogonal frequency division multiple access (OFDMA) downlink. A plurality of base stations communicate with the mobile devices and all base stations perform a distributed non-convex optimization exploiting the determined structure. | 12-03-2009 |

20090319855 | Systems and Methods for Adaptive Hybrid Automatic Retransmission Requests - A turbo coded hybrid ARQ with both IR and repetition existing in one or more transmission blocks is designed. The mixed combining is performed at the receiverâ€”Chase combining is performed for the repetitions first, followed by code combining for all code bits based on Chase combining outputs. The packet error probability is obtained by applying the union-Bhattacharyya (UB) bound for parallel channels. The throughput optimization of hybrid ARQ is determined as well as the optimal assignment rates by solving the optimization using a genetic algorithm. | 12-24-2009 |

20090323619 | DISTRIBUTED BEAMFORMING AND RATE ALLOCATION IN MULTI-ANTENNA COGNITIVE RADIO NETWORKS - Systems and methods are disclosed for designing beamforming vectors for and allocating transmission rates to secondary users in a wireless cognitive network with secondary (cognitive) users and primary (license-holding) users by performing distributed beamforming design and rate allocation for the secondary users to maximize a minimum weighted secondary rate; and granting simultaneous spectrum access to the primary and secondary users subject to one or more co-existence constraints. | 12-31-2009 |

20100042876 | System and Method for Wireless Transmission Using Hybrid ARQ Based on Average Mutual Information Per Bit - A method and system for packet transmission in a hybrid automatic repeat request (ARQ) system. A modulation and a block length for a transmission are determined based on the average mutual information per bit. The average mutual information per bit is computed based on a current channel signal-to-noise ratio and a plurality of previous transmissions, each being transmitted with a respective coded block length, modulation form, and signal-to-noise ratio. A block error rate is computed for the potential block lengths and modulations based on the average mutual information per bit, and a throughput of the current transmission is determined based on the block error rate. The modulation form and the block length of the transmission are determined based on an analysis of the throughput. If the receiver cannot decode the current transmission, the transmitter repeats the computation to determine the modulation and the block length for retransmission. | 02-18-2010 |

20100091729 | DISTRIBUTED MESSAGE-PASSING BASED RESOURCE ALLOCATION IN WIRELESS SYSTEMS - Systems and methods are disclosed to allocate resources in discrete Fourier transform spread orthogonal frequency division multiple access (DFT-S-OFDMA) networks, which involve determining a reward for each user when assigned a frequency chunk (FC) of subcarriers, where each FC is a set of contiguous subcarriers; splitting each user into one or more sub-users, with each sub-user having identical rewards; and assigning resources with a message-passing based FC allocation. | 04-15-2010 |

20100157924 | MU-MIMO-OFDMA SYSTEMS AND METHODS FOR SERVICING OVERLAPPING CO-SCHEDULED USERS - Methods and systems for conveying or transmitting to any given user in an OFDMA-MU-MIMO system scheduling information of other co-scheduled users to permit the user to perform error-correction on received data and/or interference reduction on its received signals. The scheduling information can include resource block assignment, modulation constellations employed, coding rates employed, power levels utilized and precoder matrix indices used. Further, the scheduling information can be conveyed in part through dedicated reference symbol layers or pilot streams. Moreover, a base station may transmit a preliminary estimate of the total number of users the base station expects to schedule, or an upper-bound on the total number of users, to the MU-MIMO users to permit the MU-MIMO users to determine preferred precoder matrix indices and indications of channel quality indices. | 06-24-2010 |

20100158150 | MAX-LOG STACK DECODER - A method for demodulating signals in a multi-input multi-output (MIMO) receiver includes obtaining a transformed vector by a coordinate transformation of a received observation vector using a unitary matrix determined through QR decomposition of an estimated channel matrix; maintaining a list containing nodes along with a cost metric for each node; using the list to generate soft-outputs in the form of log-likelihood ratios (LLRs) for selected symbols of interest, based on the transformed vector and a lower triangular matrix determined through QR decomposition of the estimated channel matrix and the constellations to which the input symbols belong. | 06-24-2010 |

20100232535 | Apparatus and Method for Multilayer Space-Time-Frequency Precoding for a MIMO-OFDM Wireless Transmission System - In a wireless wideband MIMO-OFDM transmission system, a method includes converting a coded bit sequence to parallel data layers, responsive to channel encoding and interleaving of an information sequence to provide the coded bit sequence; passing each data layer through a respective repetition encoder, independently interleaving respective spread data sequences from the respective repetition encoder, and amplifying the respective interleaved outputs responsive to power allocation of a respective layer of multiple layers for both I and Q channels for being combined to form complex symbols for transmission through respective multiple antennas. | 09-16-2010 |

20100271929 | CONSTELLATION RE-ARRANGEMENT AND BIT GROUPING - Methods and systems for subpacket generation using a convolutional turbo code in hybrid automatic repeat request re-transmissions that includes separating a codeword into subblocks of bits, interleaving the subblocks, and performing a permutation to group the bit streams and rearrange a symbol constellation such that bits are assigned to bit positions based on a number of re-transmissions. | 10-28-2010 |

20110010600 | LDPC Hard Decision Decoder for High-Speed Wireless Data Communications - A method for low-density parity-check hard decision decoding includes computing, for every decoding iteration, a discrepancy of extrinsic messages responsive to channel inputs of a receiver, performing a flipping of the channel inputs responsive to a comparison of the discrepancy of extrinsic messages to a flipping threshold, the flipping threshold for each decoding iteration being determined based on a threshold computation responsive to a channel error probability estimation in a first iteration of a decoding of the channel inputs, and check node decoding responsive to the flipping of channel inputs | 01-13-2011 |

20110059705 | ROBUST LINEAR PRECODER DESIGNS FOR MULTI-CELL DOWNLINK TRANSMISSION - Methods and systems for optimizing the utilities of receiver devices in a wireless communication network are disclosed. Precoder design formulations that maximize a minimum worst-case rate or a worst-case sum rate are described for both full base station cooperation and limited base station cooperation scenarios. In addition, optimal equalizers are also selected to optimize the worst-case sum rate. | 03-10-2011 |

20110069774 | Methods and Systems for Providing Feedback for Beamforming and Power Control - Methods and systems for providing feedback for beamforming and power control are provided. In some embodiments, the methods comprise: calculating a threshold associated with a subcarrier; receiving the subcarrier containing an information symbol at the receiver; determining a channel estimate of the subcarrier and a weighting vector for the information symbol; based at least on the channel estimate and the weighting vector, determining a power level of the subcarrier; comparing the power level to the threshold; generating a feedback signal indicating a first energy level to be used for the subcarrier based on the comparison; subsequent to generating the feedback signal, determining a second power level of the subcarrier; comparing the second power level to the threshold; and generating a second feedback signal to the transmitter indicating a second energy level to be used for the subcarrier. | 03-24-2011 |

20110093760 | Message-Wise Unequal Error Protection - Message-wise unequal error protection is provided using codeword flipping to separate special and ordinary codewords without discarding any codewords. Special messages are encoded to ensure the codeword weight is less than a certain threshold weight. Ordinary messages are encoded to ensure the codeword weight is greater than the threshold weight. The bits of the codeword are flipped to enforce the weight criterion. Ordinary and special messages are encoded using different encodings to provide different levels of error protection. Upon receipt, codewords are separated into special and ordinary codewords for appropriate decoding. If a codeword is of indeterminate type, it is iteratively processed as both a special codeword and an ordinary codeword. The decoding result of each process is periodically checked to determine which decoding result satisfies decoding criteria. | 04-21-2011 |

20110170457 | Transmission for Half-Duplex Relay in Fading Channel and Rateless Code Configuration - In one aspect of the invention, a method for transmission in a wireless communication system includes selecting by a signal destination one of a source-destination direct transmission, a decode-forward relay transmission, and a compress-forward transmission, responsive to channel gains between a signal source and a relay, between the signal source and the signal destination, and between the relay and the signal destination; informing a selected transmission mode from the selecting step to the signal source and the relay; and operating in the selected transmission mode by the relay. | 07-14-2011 |

20110246848 | LT DECODING AND RETRANSMISSION FOR WIRELESS BROADCAST - Methods and systems for doped rateless retransmission include receiving ratelessly coded symbols. An attempt is made to decode the coded symbols using a processor by creating an associated code graph that represents the structure of the rateless code used by the symbols. If the decoding attempt fails, an input node is selected from the code graph using a metric that gauges the number and degree of connections to the input node based on the code graph structure. The selected input node is then requested for retransmission of the selected input node by a feedback channel. | 10-06-2011 |

20120057557 | Method and Systems for Conveying Scheduling Information of Overlapping Co-Scheduled Users in an OFDMA-MU-MIMO System - Methods and systems for conveying or transmitting to any given user in an OFDMA-MU-MIMO system scheduling information of other co-scheduled users to permit the user to perform error-correction on received data and/or interference reduction on its received signals. The scheduling information can include resource block assignment, modulation constellations employed, coding rates employed, power levels utilized and precoder matrix indices used. Further, the scheduling information can be conveyed in part through dedicated reference symbol layers or pilot streams. Moreover, a base station may transmit a preliminary estimate of the total number of users the base station expects to schedule, or an upper-bound on the total number of users, to the MU-MIMO users to permit the MU-MIMO users to determine preferred precoder matrix indices and indications of channel quality indices. | 03-08-2012 |

20120057558 | Method and Systems for Conveying Scheduling Information of Overlapping Co-Scheduled Users in an OFDMA-MU-MIMO System - Methods and systems for conveying or transmitting to any given user in an OFDMA-MU-MIMO system scheduling information of other co-scheduled users to permit the user to perform error-correction on received data and/or interference reduction on its received signals. The scheduling information can include resource block assignment, modulation constellations employed, coding rates employed, power levels utilized and precoder matrix indices used. Further, the scheduling information can be conveyed in part through dedicated reference symbol layers or pilot streams. Moreover, a base station may transmit a preliminary estimate of the total number of users the base station expects to schedule, or an upper-bound on the total number of users, to the MU-MIMO users to permit the MU-MIMO users to determine preferred precoder matrix indices and indications of channel quality indices. | 03-08-2012 |

20120140850 | Codebook Method for a Multiple Input Multiple Output Wireless System - A method for wireless encoding includes encoding wireless multiple input and multiple output signals in accordance with a codebook being one of a discrete codebook restricting elements of codebook entries to be within a predetermined finite set of complex numbers and a constant amplitude codebook including each entry in its codebook having equal column norm and equal row norm. In a preferred embodiment the digital codebook further includes restricting elements of a finite set in the discrete codebook to be in the form of k | 06-07-2012 |

20120163332 | COORDINATED LINEAR BEAMFORMING IN DOWNLINK MULTI-CELL WIRELESS NETWORKS - System and methods are disclosed for optimizing wireless communication for a plurality of mobile wireless devices. The system uses beamforming vectors or precoders having a structure optimal with respect to the weighted sum rate in a multi-cell orthogonal frequency division multiple access (OFDMA) downlink. A plurality of base stations communicate with the mobile devices and all base stations perform a distributed non-convex optimization exploiting the determined structure. | 06-28-2012 |

20120170676 | Robust Linear Precoder Designs for Multi-Cell Downlink Transmission - Methods and systems for optimizing the utilities of receiver devices in a wireless communication network are disclosed. Precoder design formulations that maximize a minimum worst-case rate or a worst-case sum rate are described for both full base station, cooperation and limited base station cooperation scenarios. In addition, optimal equalizers are also selected to optimize the worst-case sum rate. | 07-05-2012 |

20120170677 | COORDINATED LINEAR BEAMFORMING IN DOWNLINK MULTI-CELL WIRELESS NETWORKS - System and methods are disclosed for optimizing wireless communication for a plurality of mobile wireless devices. The system uses beamforming vectors or precoders having a structure optimal with respect to the weighted sum rate in a multi-cell orthogonal frequency division multiple access (OFDMA) downlink. A plurality of base stations communicate with the mobile devices and all base stations perform a distributed non-convex optimization exploiting the determined structure. | 07-05-2012 |

20120224649 | MULTI-RESOLUTION PRECODING CODEBOOK - Systems and methods are for generating a codebook by: generating a multi-resolution codebook by selecting a common precoder index from a low resolution codebook for a group of adjacent resource blocks (RB)s and for each RB within the group, selecting a high-resolution codebook to fine-tune each RB precoder; and generating feedback for the multi-resolution codebook by quantizing channel state variations. | 09-06-2012 |

20120250791 | Codebook Method for a Multiple Input Multiple Output Wireless System - A method for wireless encoding includes encoding wireless multiple input and multiple output signals in accordance with a codebook being one of a discrete codebook restricting elements of codebook entries to be within a predetermined finite set of complex numbers and a constant amplitude codebook including each entry in its codebook having equal column norm and equal row norm. In a preferred embodiment the digital codebook further includes restricting elements of a finite set in the discrete codebook to be in the form of k | 10-04-2012 |

20120275535 | Codebook Method for a Multiple Input Multiple Output Wireless System - A method for wireless encoding includes encoding wireless multiple input and multiple output signals in accordance with a codebook being one of a discrete codebook restricting elements of codebook entries to be within a predetermined finite set of complex numbers and a constant amplitude codebook including each entry in its codebook having equal column norm and equal row norm. In a preferred embodiment the digital codebook further includes restricting elements of a finite set in the discrete codebook to be in the form of k | 11-01-2012 |

20120281662 | Scheduling Information of Overlapping Co-Scheduled Users in an OFDMA-MU-MIMO System - A user equipment (UE) used in a multi-user (MU)-multiple input multiple output (MIMO) orthogonal frequency division multiple access (OFDMA) system is disclosed. The UE includes a receiving unit to receive from a base station an indication of an estimate of or an upper-bound on the total number of MU-MIMO user equipments (|S|) that are scheduled on a sub-band by the base station, wherein the sub-band includes one or more resource units, a calculation unit to calculate channel quality based on the indication of the estimate of or the upper-bound on the total number of MU-MIMO user equipments, and a transmission unit to transmit to the base station an indication of the channel quality. Other methods and apparatuses also are disclosed. | 11-08-2012 |

20130034176 | ROBUST LINEAR PRECODER DESIGNS FOR MULTI-CELL DOWNLINK TRANSMISSION - Methods and systems for optimizing the utilities of receiver devices in a wireless communication network are disclosed. Precoder design formulations that maximize a minimum worst-case rate or a worst-case sum rate are described for both full base station cooperation and limited base station cooperation scenarios. In addition, optimal equalizers are also selected to optimize the worst-case sum rate. | 02-07-2013 |

20130094453 | MULTI-RESOLUTION PRECODING CODEBOOK - Systems and methods are for generating a codebook by: generating a multi-resolution codebook by selecting a common precoder index from a low resolution codebook for a group of adjacent resource blocks (RB)s and for each RB within the group, selecting a high-resolution codebook to fine-tune each RB precoder; and generating feedback for the multi-resolution codebook by quantizing channel state variations. | 04-18-2013 |

20130170445 | Multi-user downlink linear MIMO precoding system - A method implemented in a base station used for a downlink multi-user (MU) multi-input multi-output (MIMO) system is disclosed. The method includes receiving an indication of a quantized matrix from each of a plurality of scheduled user equipments, precoding data streams for the plurality of scheduled user equipments, transmitting the precoded data to the plurality of scheduled user equipments. Other methods and some apparatuses for wireless communications also are disclosed. | 07-04-2013 |

20130230116 | 09-05-2013 | |

20130242926 | METHODS AND SYSTEMS FOR CONVEYING SCHEDULING INFORMATION OF OVERLAPPING CO-SCHEDULED USERS IN AN OFDMA-MU-MIMO SYSTEM - A method implemented in a base station for conveying scheduling information in an orthogonal frequency division multiple access (OFDMA) multi-user (MU)-multiple input multiple output (MIMO) system is disclosed. The method includes transmitting to a first user equipment (UE) the scheduling information including first scheduling information of the first UE and at least a portion of second scheduling information of at least one second UE, wherein the scheduling information includes a resource block (RB) assigned to the first UE, the number of streams, and an indication of one or more dedicated reference symbol (RS) layers assigned to the first UE. Other methods, systems, and apparatuses also are disclosed. | 09-19-2013 |

20130272440 | Transmission of an Information Sequence - A method implemented in a mobile communications system for data transmission is disclosed. The method includes selecting a set of parallel channels, determining transmission rank, and determining a precoding matrix of the transmission rank for the set of parallel channels, wherein the precoding matrix is formed by applying householder transformation to a vector to make a matrix and selecting one or more columns from the matrix. Other methods and apparatuses also are disclosed. | 10-17-2013 |

20140024316 | Methods, Systems, and Media for Detecting Usage of a Radio Channel - Methods, systems, and media for detecting usage of a radio channel are provided. In some embodiments, methods for detecting usage of a radio channel are provided, the methods comprising: collecting noise samples on the radio channel from a radio receiver; determining a noise empirical cumulative distribution function using a hardware processor; collecting signal samples on the radio channel from the radio receiver; determining a signal empirical cumulative distribution function using a hardware processor; calculating a largest absolute difference between the noise empirical cumulative distribution function and the signal empirical cumulative distribution function using a hardware processor; and determining that the radio channel is being used when the largest absolute difference is greater than a threshold using a hardware processor. | 01-23-2014 |

20140334567 | MULTI-RESOLUTION PRECODING CODEBOOK - A method implemented in a base station used in a wireless communications system is disclosed. The method includes receiving, from a mobile station, a low resolution precoder matrix index for a plurality of resource blocks (RBs), receiving, from the mobile station, a high resolution precoder matrix index for part of the plurality of RBs, and transmitting, to the mobile station, data precoded with a precoder matrix, wherein the precoder matrix is determined from a codebook according to the low resolution precoder matrix index and the high resolution precoder matrix index. Other methods, apparatuses, and systems also are disclosed. | 11-13-2014 |