Patent application number | Description | Published |
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 |
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 |
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 |
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 receiver—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 |
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 |
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 |
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 |
20110222616 | MIMO Transmission with Rank Adaptation for Multi-Gigabit 60 GHz Wireless - A wireless system includes a transmitter with a baseband processor responsive to groups of transmitter antenna arrays for communicating over directional beams; and a receiver with a baseband processor responsive to groups of receiver antenna rays for communicating with the transmitter over the directional beams, the receiver including both a rank adaptation providing a transmit mode feedback to the transmitter and a blind beamforming providing a transmit beamformer index feedback to the transmitter and receiver groups of antenna arrays. | 09-15-2011 |
20110223910 | EFFICIENT CHANNEL SEARCH WITH SEQUENTIAL PROBABILITY RATIO TESTING - Methods and systems for cognitive radio channel searching are shown that include determining an upper threshold and a lower threshold that will find a free channel in a minimum average searching time based on a channel occupancy probability π0 and the number of channels K, constrained by a target acceptable misdetection probability and a target acceptable false alarm probability. The K channels are searched with a signaling device using the determined upper threshold and lower threshold to find a free channel. | 09-15-2011 |
20110223911 | EFFICIENT CHANNEL SEARCH WITH ENERGY DETECTION - Methods and systems for cognitive radio channel searching are shown that include determining an energy detection threshold and a number of samples that will find a free channel in a minimum searching time, based on a number of channels K and a channel occupancy probability π0, constrained by a target acceptable misdetection probability and a target acceptable false alarm probability. The search includes an energy detection threshold and a number of samples that will find a free channel in a minimum average searching time. The K channels are searched with a signaling device using the determined energy detection threshold and the determined number of samples to find a free channel. | 09-15-2011 |
20110243017 | MU-MIMO-OFDMA SYSTEMS AND METHODS FOR MULTI-RANK CQI COMPUTATION AND PRECODER SELECTION - Methods and systems for determining attributes of communication channels of MU-MIMO users in an OFDMA system are disclosed. One method comprises receiving from a base station, for at least one sub-band of contiguous sub-carriers, an indication of an estimate of or an upper-bound on a total number of streams that are co-scheduled by the base station on the at least one sub-band. In addition, the method further comprises determining one or more signal quality measures for the at-least one sub-band based on the estimate of or the upper-bound on the total number of streams that are scheduled by the base station on the at least one sub-band. Moreover, an indication of the one or more signal quality measures is transmitted to the base station. | 10-06-2011 |
20110243018 | MU-MIMO-OFDMA METHODS AND SYSTEMS FOR SIGNALING MULTI-RANK CQIs AND PRECODERS - Methods and systems for determining attributes of communication channels of MU-MIMO users in an OFDMA system are disclosed. One method includes receiving from a base station, for at least one sub-band of contiguous sub-carriers, an indication of an estimate of or an upper-bound on a total number of streams that are co-scheduled by the base station on the at least one sub-band and an indication of a fraction of a transmit power at the base station that is applied to streams that are scheduled for transmission to a particular user. The method further includes determining one or more signal quality measures for the at least one sub-band based on at least one of the fraction or the estimate of or the upper-bound on the total number of streams that are scheduled by the base station on the at least one sub-band. In addition, an indication of the one or more signal quality measures is transmitted to the base station in the method. | 10-06-2011 |
20110243019 | MU-MIMO-OFDMA MULTI-RANK CQI AND PRECODER SIGNALING SCHEMES - Methods and systems for determining attributes of communication channels of MU-MIMO users in an (OFDMA) system are disclosed. One method includes receiving from a base station, for at least one sub-band of contiguous sub-carriers, an indication of an estimate of or an upper-bound on a total number of streams that are co-scheduled by the base station on the at least one sub-band. The method further includes determining one or more signal quality measures for the at least one sub-band based on the estimate of or the upper-bound on the total number of streams that are scheduled by the base station on the at least one sub-band in accordance with at least one of single-user scheduling rules or multi-user scheduling rules. In addition, the method includes transmitting to the base station an indication of the one or more signal quality measures and at least one tag identifying each signal quality measure as being determined in accordance with the single-user scheduling rules or the multi-user scheduling rules. | 10-06-2011 |
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 |
20110255582 | SELECTIVE JOINT DEMODULATION - Systems, methods and apparatuses for jointly demodulating data signals are disclosed. In accordance with the method, pilot signals are received from a base station and are processed. In addition, from a set of expected co-scheduled data streams, a subset of the co-scheduled data streams that are actually transmitted by the base station are determined based on the pilot signals. Further, a group of the transmitted co-scheduled data streams are selected from the determined subset. The data signals are received and jointly demodulated by employing the selected group of co-scheduled data streams and by suppressing non-selected data streams from the determined subset. | 10-20-2011 |
20120069757 | Low Complexity Link Adaptatation for LTE/LTE-A Uplink with a Turbo Receiver - An inventive method for link adaptation for an LTE/LTE-A uplink with a turbo SIC receiver includes the steps of determining a precoding matrix index PMI and rank index RI selection for an LTE/LTE-A uplink when precoding of the uplink is enabled, responsive to channel state information of a subcarrier in the uplink; determining a decoding order for codewords in the uplink i) when the precoding of the uplink is not enabled and ii) if needed when the precoding of the uplink is enabled; performing modulation and coding scheme MCS assignment for the uplink based on a hard decision successive interference cancellation SIC rule (without intra-CW cancellation) or a partial hard decision successive interference cancellation SIC rule (with intra-CW cancellation), responsive to the determined PMI and RI selection; and influencing data transmission in the uplink responsive to the MCS assignment for detection by a turbo SIC receiver. | 03-22-2012 |
20120069924 | LINEAR PRECODING IN MIMO BROADCAST CHANNEL WITH ARBITRARY RANK CONSTRAINTS - Methods and systems for transmission are shown that include iteratively generating an optimized precoder matrix and optimized linear filters for multiple receivers, where the optimized precoder matrix is based on a linear filter from a previous iteration and the optimized linear filters the multiple receivers are based on a precoder matrix from a previous iteration, precoding an input stream using the iteratively generated optimized precoder matrix to produce transmission streams for the multiple receivers, where at least one receiver has a plurality of associated transmission streams, and transmitting the transmission streams with multiple antennas to the receivers. | 03-22-2012 |
20120082259 | Precoding Selection for Retransmission in Uplink MIMO Hybrid ARQ - A method includes obtaining a precoder for retransmission of one codeword responsive to a known precoding matrix of a certain rank and modulation and coding scheme assignments used in an original transmission, and a desired retransmission rank', forming an approximate channel covariance matrix; stimating an a minimum mean square error receiver signal-to-noise-interference-ratio for each layer to be retransmitted responsive to the prior forming; and finding a precoding matrix from a preceding codebook that maximizes a sum-rate for enabling precoding selections for retransmissions in uplink multiple-input multiple-output MIMO hybrid automatic repeat request HARQ. | 04-05-2012 |
20120114030 | Power Scaling for Retransmissions in Uplink MIMO Hybrid ARQ - A method includes obtaining a precoder for retransmission of one codeword responsive to known precoding matrix P of rank r and modulation and coding scheme MCS assignments used in an original transmission, and a desired retransmission rank r′; and scaling power in the retransmission responsive to at least two of 1) information parameters Index of UL precoder in previous transmission, 2) rank r of uplink UL precoder in previous transmission, 3) MCS assignments in previous retransmission (MCS | 05-10-2012 |
20120170531 | RESOURCE ALLOCATION IN 4G MIMO CELLULAR UPLINKS - Methods and systems for allocating resources in a cellular uplink include iteratively allocating uplink resource blocks (RBs) to a plurality of user devices in a multiple-input multiple-output network. Allocation is performed subject to constraints and incremental utility maximization according to an approximation that has a worst-case guarantee. | 07-05-2012 |
20120257664 | Method for Improving Multiuser MIMO Downlink Transmissions - A method for improving multiple-input multiple-output MIMO downlink transmissions includes obtaining a channel state information CSI report including preferred matrix index PMI for precoding, channel quality index CQI and rank index RI at a base station from user terminals through a channel feedback; applying selectively a signal-to-interference-plus-noise-ratio SINR offset to a SINR of said CSI report; applying selectively a rate matching responsive to SINR offset or the CSI report; and controlling or adjusting the SINR offset. | 10-11-2012 |
20120275313 | Enhancement of Download Multi-User Multiple-Input Multiple-Output Wireless Communications - A method implemented in a user equipment configured to be used in a multi-user (MU) multiple-input multiple-output (MIMO) wireless communications system is disclosed. In an aspect, the user equipment transmits to a base station a first channel state information (CSI) report determined according to a single-user (SU) MIMO rule and a second CSI report based on a residual error. | 11-01-2012 |
20120275314 | Enhancement of Download Multi-User Multiple-Input Multiple-Output Wireless Communications - A method implemented in a user equipment configured to be used in a multi-user (MU) multiple-input multiple-output (MIMO) wireless communications system is disclosed. In an aspect, the user equipment transmits to a base station a first channel state information (CSI) report determined according to a single-user (SU) MIMO rule and a second CSI report determined according to an MU-MIMO rule. | 11-01-2012 |
20120294381 | Multi-User Multiple Input Multiple Output Wireless Communications - A method implemented in a user equipment used in a multi-user multiple input multiple output (MU-MIMO) wireless communications system is disclosed. The method includes receiving from a base station an indication of a first modulation type for the user equipment, receiving a first data signal for the user equipment, receiving a second data signal for a co-scheduled user equipment, where a second modulation type for the co-scheduled user equipment is unknown to the user equipment, and deciding the second modulation type. Other methods, systems, and apparatuses also are disclosed. | 11-22-2012 |
20130101063 | DFT-BASED CHANNEL ESTIMATION SYSTEMS AND METHODS - DFT-based channel estimation methods and systems are disclosed. One system includes an inverse discrete Fourier transform module, a noise power estimator, a noise filter and a discrete Fourier transform module. The inverse discrete Fourier transform module is configured to determine time domain estimates by applying an inverse discrete Fourier transform to initial channel estimates computed from pilot signals. Additionally, the noise power estimator is configured to estimate noise power by determining and utilizing time domain samples that are within a vicinity of sinc nulls of the time domain estimates. The noise filter is configured to filter noise from the time domain estimates based on the estimated noise power to obtain noise filtered time domain estimates. Further, the discrete Fourier transform module is configured to perform a discrete Fourier transform on the noise filtered time domain estimates to obtain frequency domain channel estimates for channels on which pilot signals are transmitted. | 04-25-2013 |
20130229992 | Coordinated Multiple Point Transmission and Reception - A method implemented in a mobile communications network supporting coordinated multiple point transmission and reception (CoMP) is disclosed. The method includes transmitting, to a user equipment (UE), data in a physical downlink shared channel (PDSCH), and transmitting a reference signal to the UE, wherein a union of resource elements (REs) allocated for reference signals transmitted from a subset of a plurality of transmission points (TPs) in a CoMP set are excluded from resource mapping for transmitting the data to the UE. Other methods, systems, and apparatuses also are disclosed. | 09-05-2013 |
20130250868 | User Pairing and Resource Allocation for Downlink Multiuser Multi-Input-Multi-Output In Long Term Evolution Advanced Systems - A method for user pairing and resource allocation, includes performing a multiuser multi-input-multi-output (MU-MIMO) user pairing process to maximize an objective metric without common rank restriction; performing a rank balancing process to determine a uniform transmission user rank along all allocated resource blocks for each user; and with the uniform transmission user rank fixed for all the users, determining optimal user pairing and allocation for each of the resource blocks for each user. | 09-26-2013 |
20140086178 | Buffer-Aware Packet Scheduling for Downlink Multiuser Systems - An inventive duffer aware adaptive BAA scheduler considers both channel and buffer conditions to make scheduling decisions. Specifically, channel conditions are used to select candidate users, i.e., only the users whose transmission rates satisfy a certain condition are considered as candidate users. It guarantees a maximum of throughput deduction. Then the buffer conditions are used to make scheduling decisions among all the candidate users, i.e., the user with largest queue backlog among candidate users will be scheduled, to provide improved delay performance. | 03-27-2014 |
20140133325 | Feedback and Scheduling for Coordinated Multi-Point (CoMP) Joint Transmission (JT) in Orthogonal Frequency Division Multiple Access (OFDMA) - A method implemented in a user equipment (UE) used in an orthogonal frequency division multiple access (OFDMA) wireless communications system supporting coordinated multi-point (CoMP) joint transmission (JT) is disclosed. The method includes measuring reference signal received power (RSRP), transmitting, to a network, first feedback on the RSRP, receiving, from the network, a CoMP measurement set, conducting pre-scheduling CoMP UE fallback according to the CoMP measurement set, computing channel quality and direction information according to a UE category, and transmitting, to the network, second feedback on the channel quality and direction information. Other methods, apparatuses, and systems also are disclosed. | 05-15-2014 |
20140198750 | Multi-User (MU) Multiple-Input and Multiple-Output (MIMO) Enhancement - A method implemented in a base station used in a mobile communications system is disclosed. The method includes configuring for a user equipment (UE) a channel state information (CSI) process for multi-user (MU) multiple-input and multiple-output (MIMO), the CSI process for MU-MIMO being associated with a channel part and an interference part, and according to the interference part, configuring the UE to measure or estimate inter-cell interference (ICI) and to compute or estimate intra-cell interference. Other apparatuses, systems, and methods also are disclosed. | 07-17-2014 |
20140198751 | Channel Feedback for Vertical and Full-Dimensional Beamforming - A method implemented in a base station used in a wireless communications system where different antenna arrays are employed for transmissions to different co-scheduled users in a cell is disclosed. The method includes configuring multiple channel state information (CSI) processes for a user equipment (UE), and configuring, for the UE, a plurality of non-zero power (NZP) CSI reference signal (RS) resources, each of which is associated with an antenna array. Other apparatuses, systems, and methods also are disclosed. | 07-17-2014 |
20140219379 | Precoding Selection for Retransmission in Uplink MIMO Hybrid ARQ - A method implemented in a user terminal is disclosed. The method comprises obtaining known precoding matrix P of rank r and modulation and coding scheme assignments used in an original transmission, and a desired retransmission rank r′, forming an approximate channel covariance matrix, estimating a minimum mean square error receiver SINR for each layer to be retransmitted responsive to said forming, and finding a retransmission precoding matrix from a preceding codebook that maximizes a sum-rate for enabling precoding selections for retransmissions in uplink multiple-input multiple-output MIMO hybrid automatic repeat request HARQ. Other methods, apparatuses, and systems also are disclosed. | 08-07-2014 |
20140233414 | MU-MIMO-OFDMA METHODS AND SYSTEMS FOR SIGNALING MULTI-RANK CQIs AND PRECODERS - A method for determining attributes of communication channels of multi-user (MU)-multiple input multiple output (MIMO) users in an orthogonal frequency division multiplexing based multiple access (OFDMA) system is disclosed. The method comprises receiving from a base station, for at least one sub-band of contiguous sub-carriers, an indication of an estimate of or an upper-bound on a total number of streams that are co-scheduled by the base station on the at least one sub-band or an indication of a fraction of a transmit power at the base station that is applied to streams that are scheduled for transmission to a particular user, determining one or more signal quality measures for the at least one sub-band based on at least one of the fraction or the estimate of or the upper-bound on the total number of streams that are scheduled by the base station on the at least one sub-band, and transmitting to the base station an indication of the one or more signal quality measures. Other methods, apparatuses, and systems also are disclosed. | 08-21-2014 |
20140241449 | Codebook Construction - A method implemented in a base station used in a wireless communications system is disclosed. The method comprises having a codebook including a plurality of precoding matrices, precoding data with one of the plurality of precoding matrices, and transmitting, to a user equipment, the precoded data, wherein each precoding matrix W satisfies W=W | 08-28-2014 |
20140241450 | Codebook Construction - A method implemented in a base station used in a wireless communications system is disclosed. The method comprises having 1-layer, 2-layer, 3-layer, and 4-layer codebooks for 4 transmit antenna (4TX) transmission, each codebook including a plurality of precoding matrices, precoding data with one of the plurality of precoding matrices, and transmitting, to a user equipment, the precoded data, wherein each of the 1-layer and 2-layer codebooks comprises a first codebook and a second codebook, and wherein each precoding matrix in the first codebook comprises a first index and a second index. Other apparatuses, systems, and methods also are disclosed. | 08-28-2014 |
20140341064 | Enhancement of Download Multi-User Multiple-Input Multiple-Output Wireless Communications - A method implemented in a user equipment configured to be used in a multi-user (MU) multiple-input multiple-output (MIMO) wireless communications system is disclosed. The method includes transmitting to a base station a first channel state information (CSI) report determined according to a single-user (SU) MIMO rule, and transmitting to the base station a second CSI report determined according to an MU-MIMO rule. Other methods, apparatuses, and systems also are disclosed. | 11-20-2014 |
20140362783 | Channel State Information (CSI) Feedback and Subsampling - A method implemented in a base station used in a wireless communications system is disclosed. The method comprises receiving, from a user equipment, rank indication (RI), a first precoding matrix indicator (PMI), and a second PMI, the RI and the first PMI being jointly encoded, wherein 5 bits are used for transmission of the jointly encoded RI and first PMI, and wherein first 8 values of values expressed by the 5 bits are used for RI=1, second 8 values of the values expressed by the 5 bits are used for RI=2, a third value of the values expressed by the 5 bits is used for RI=3, a fourth value of the values expressed by the 5 bits is used for RI=4, and remaining 14 values of the values expressed by the 5 bits are reserved. Other methods, apparatuses, and systems also are disclosed. | 12-11-2014 |
20140362784 | Channel State Information (CSI) Feedback and Subsampling - A method implemented in a base station used in a wireless communications system is disclosed. The method comprises receiving, from a user equipment, rank indication (RI), a first precoding matrix indicator (PMI), and a second PMI (codebook index i | 12-11-2014 |
20140362940 | Channel State Information (CSI) Feedback and Subsampling - A method implemented in a base station used in a wireless communications system is disclosed. The method comprises receiving, from a user equipment, rank indication (RI), a first precoding matrix indicator (PMI) (codebook index i | 12-11-2014 |