摘要:
A greater likelihood decoder, a method of deriving a reduced substreams maximum likelihood (RSML) decoded symbol vector and a multiple-input, multiple-output (MIMO) receiver incorporating the decoder or the method. In one embodiment, the decoder includes: (1) a suboptimal decoder that analyzes a received symbol vector to generate substream indicators and a decoded symbol vector estimate, (2) weakest substreams decision logic, coupled to the suboptimal decoder, that receives the substream indicators and selects weakest ones thereof and (3) subspace search logic, coupled to the suboptimal decoder and the weakest substreams decision logic, that further selects a reduced substreams maximum likelihood (RSML) decoded symbol vector from a subspace of decoded symbol vector candidates derived from the decoded symbol vector estimate and the weakest ones.
摘要:
A reduced search space minimum distance decoding method provides average probability of error performance close to optimal MAP decoding. The decoding algorithm provides dramatic complexity reductions compared with MAP decoding. A a sub-optimal decoder receives a collection of signal vectors y1 . . . yk, with k denoting a positive integer and generates an estimated transmitted multidimensional symbol {tilde over (S)}. The estimated transmitted multidimensional symbol {tilde over (S)} is decoded using hierarchical subset decoding a subset is determined therefrom. A reduced search space V is generated and minimum distance decoding is used to decode the received symbol vectors y1 . . . yk in the reduced search space V. one or more of the following: an estimated multidimensional symbol {tilde over (S)}, soft bit information, or hard bit information are cienerated therefrom.
摘要:
A channel norm-based ordering and whitened decoding technique (lower complexity iterative decoder) for MIMO communication systems performs approximately the same level of performance as an iterative minimum mean squared error decoder. Decoding a signal vector comprises receiving a signal vector yk, multiplying the received signal vector yk by a conjugate transpose of a channel matrix H*. A column vector zk is generated. The entries of the column vector zk are reordered and an estimated channel matrix {tilde over (H)} is generated. The estimated channel matrix {tilde over (H)} decomposed using a Cholesky decomposition and generating a triangular matrix L. Triangular matrix L is solved backwards and a signal vector {tilde over (s)}k estimated. An estimate of the transmitted symbol vector Ŝk is generated.
摘要翻译:用于MIMO通信系统的基于信道规范的排序和白化解码技术(较低复杂度迭代解码器)执行与迭代最小均方误差解码器大致相同的性能水平。 对信号矢量进行解码包括:将接收信号矢量y N k乘以通道矩阵H *的共轭转置的信号矢量y k k。 生成列向量z SUB>。 列向量z 的条目被重新排序,并且生成估计的信道矩阵H. 估计的信道矩阵H使用Cholesky分解分解并产生三角矩阵L.三角矩阵L向后求解并且估计信号矢量s N k。 生成发送的符号矢量S N k的估计。
摘要:
A reduced search space minimum distance decoding algorithm provides average probability of error performance close to that of optimal MAP decoding. The decoding algorithm provides dramatic complexity reductions compared with MAP decoding. A sub-optimal decoder receives signal vectors y1 . . . yk. Soft output bits are generated as is a reduced search space V via a reduced search space table creation unit in response to the soft output bits and an estimated channel H. A signal vector b is generated via a maximum likelihood decoding unit in response to the reduced search space V and the signal vectors y1 . . . yk.
摘要:
A method of communicating in a wireless network including a plurality of nodes having communications devices including a first node, wherein at least one node utilizes a first physical layer (PHY) modulation, and at least one other node utilizes a second PHY modulation different from the first PHY modulation. The first node receives a PHY frame transmitted by one of the plurality of nodes, and identifies a PHY modulation type selected from the first PHY modulation and the second PHY modulation used in the PHY frame or to be used in a subsequently to be received PHY frame or frame portion. The first node decodes the PHY frame or the subsequently to be received PHY frame or frame portion using the PHY modulation type identified in the identifying step.
摘要:
A method and system for estimating noise variance. A method for noise variance estimation comprises receiving a first multi-sample symbol and receiving a second multi-sample symbol. The first multi-sample symbol is subtracted from the second multi-sample symbol to produce a set of noise samples. The set of noise samples is used to produce a noise variance estimate. The noise variance estimate is applied in various tasks (e.g. channel estimation, log-likelihood ratio computation, and/or minimum mean squared error equalization) to process data provided to a user.
摘要:
Disclosed herein is a system and method for determining the presence of rotated-BPSK modulation. In addition, disclosed herein is a system and method for determining if a received packet is a Legacy, Mixed-Mode, or Green-Field packet in accordance with the determination of the presence of rotated-BPSK modulation. The presence of a Green-Field packet may be determined by detecting if additional tones are being excited in an LTF symbol of the received packet and/or if a SIG field symbol following the LTF symbol is modulated by rotated-BPSK. The presence of a Mixed-Mode packet may be determined by detecting if the first four bits of the SIG field symbol following the LTF symbol are [1 1 0 1] and/or detecting if a symbol following an L-SIG symbol is modulated by rotated-BPSK. The presence of a Legacy packet may be determined by detecting if the symbol following the L-SIG symbol is modulated by BPSK.
摘要:
The present invention is directed to a time-switched preamble generator and method of generating a time-switched preamble for use with a multiple-input, multiple-output (MIMO) transmitter employing first and second transmit antennas. In one embodiment, the time-switched preamble generator includes an initial preamble formatter configured to provide a first preamble to the first transmit antenna and a second preamble to the second transmit antenna during an initial time interval. The time-switched preamble generator also includes a subsequent preamble formatter coupled to the initial preamble formatter and configured to provide the second preamble to the first transmit antenna and the first preamble to the second transmit antenna during a subsequent time interval.
摘要:
Embodiments of the invention provide a system and method of hybrid automatic repeat-request (HARQ) processing. A viterbi decoder is coupled to and follows a descrambler. After the signal has been de-scrambled, it can be stored in a memory in case it needs to be recombined with another packet. This means that the log-likelihood ratios LLRs for each transmitted bit are stored in memory using a finite number of bits (for example, between 4 and 12 bits). If the packet that is currently being processed contains retransmitted information, then the de-scrambled output stored from a previous packet containing the same information can be loaded and combined with the current packet.
摘要:
In at least some embodiments, a receiver for a wireless communication system is provided. The receiver includes an equalizer that provides an equalized channel matrix. The receiver also includes scaling logic coupled to the equalizer, the scaling logic selectively scales coefficients of the equalized channel matrix. The receiver also includes a decoder coupled to the scaling logic. The decoder decodes a signal based on the equalized channel matrix with scaled coefficients.