摘要:
Symbol by symbol variable code rate capable communication device. A communication device is operable to perform processing of a variable code rate signal whose code rate varies on a symbol by symbol basis. This may involve performing encoding of input to generate the variable code rate signal; alternatively, this may involve performing decoding of a variable code rate signal. In doing so, this approach may involve using a single encoder and/or decoder (depending on the application). In some instances, a single device is operable to encode a first variable code rate signal (for transmission to another device) and to decode a second variable code rate signal (that has been received from another device). In addition, a method of coding (including one or both of encoding and decoding) may also operate of a variable code rate signal whose code rate varies on a symbol by symbol basis.
摘要:
LDPC (Low Density Parity Check) coded modulation symbol decoding using non-Gray code maps for improved performance. Symbol decoding is supported by appropriately modifying an LDPC tripartite graph to eliminate the bit nodes thereby generating an LDPC bipartite graph (such that symbol nodes are appropriately mapped directly to check nodes thereby obviating the bit nodes). The edges that communicatively couple the symbol nodes to the check nodes are labeled appropriately to support symbol decoding of the LDPC coded modulation signal. In addition, the LDPC coded modulation symbol decoding can be employed to decode a signal that has been encoded using LDPC-BICM (Low Density Parity Check-Bit Interleaved Coded Modulation) encoding with non-Gray code mapping. By using the non-Gray code mapping, a performance improvement over such a system using only Gray code mapping may be achieved.
摘要:
LDPC (Low Density Parity Check) coded modulation hybrid decoding. A novel approach is presented wherein a combination of bit decoding and symbol level decoding (e.g., hybrid decoding) is performed for LDPC coded signals. Check node updating and symbol node updating are successively and alternatively performed on bit edge messages for a predetermined number of decoding iterations or until a sufficient degree of precision is achieved. The symbol node updating of the bit edge messages involves using symbol metrics corresponding to the symbol being decoded as well as the bit edge messages most recently updated by check node updating. The check node updating of the bit edge messages involves using the bit edge messages most recently updated by symbol node updating. The symbol node updating also involves computing possible soft symbol estimates for the symbol during each decoding iteration.
摘要:
Variable modulation within combined LDPC (Low Density Parity Check) coding and modulation coding systems. A novel approach is presented for variable modulation encoding of LDPC coded symbols. In addition, LDPC encoding, that generates an LDPC variable code rate signal, may also be performed as well. The encoding can generate an LDPC variable code rate and/or modulation signal whose code rate and/or modulation may vary as frequently as on a symbol by symbol basis. Some embodiments employ a common constellation shape for all of the symbols of the signal sequence, yet individual symbols may be mapped according different mappings of the commonly shaped constellation; such an embodiment may be viewed as generating a LDPC variable mapped signal. In general, any one or more of the code rate, constellation shape, or mapping of the individual symbols of a signal sequence may vary as frequently as on a symbol by symbol basis.
摘要:
16 QAM (Quadrature Amplitude Modulation) and 16 APSK (Asymmetric Phase Shift Keying) TTCM (Turbo Trellis Coded Modulation) with minimum bandwidth efficiency of 3 bit/s/Hz (bits per second per Hertz) using a rate 2/4 constituent encoder. Various encoder designs are presented that are operable to generate a signal whose modulation may vary as frequently as on a symbol by symbol basis while providing relatively very high throughput. Rate control sequences including RCs (Rate Controls), arranged in a period, govern the manner in which symbols of a signal are generated. The RCs correspond to various modulations that may each have a unique constellation and corresponding mapping. Different RCs may be included within a rate control sequence that correspond to 16 QAM, 16 APSK, QPSK (Quadrature Phase Shift Key), or even other modulation types. In addition, 1 or more uncoded bits may be used to generate the symbols of the coded signal.
摘要翻译:使用速率2/4分量编码器,具有最小带宽效率为3位/ s / Hz(每赫兹每秒赫兹)的TTCM(Turbo网格编码调制)和16 APSK(非对称相移键控)TAPM(非对称相移键控))。 提供了各种编码器设计,其可操作以产生其调制可以像逐个符号基础一样频繁地变化的信号,同时提供相对非常高的吞吐量。 包括RC(速率控制)在内的速率控制序列被布置在一个周期内,控制信号的符号产生的方式。 RC对应于各自可以具有独特的星座和相应映射的各种调制。 不同的RC可以包括在对应于16QAM,16APSK,QPSK(正交相移键))或甚至其它调制类型的速率控制序列中。 此外,可以使用1个或多个未编码比特来生成编码信号的符号。
摘要:
Variable modulation within combined LDPC (Low Density Parity Check) coding and modulation coding systems. Variable modulation encoding of LDPC coded symbols is presented. In addition, LDPC encoding, that generates an LDPC variable code rate signal, may also be performed as well. The encoding can generate an LDPC variable code rate and/or modulation signal whose code rate and/or modulation may vary as frequently as on a symbol by symbol basis. Some embodiments employ a common constellation shape for all of the symbols of the signal sequence, yet individual symbols may be mapped according different mappings of the commonly shaped constellation; such an embodiment may be viewed as generating a LDPC variable mapped signal. In general, any one or more of the code rate, constellation shape, or mapping of the individual symbols of a signal sequence may vary as frequently as on a symbol by symbol basis.
摘要:
True bit level decoding of TTCM (Turbo Trellis Coded Modulation) of variable rates and signal constellations. A decoding approach is presented that allows for decoding on a bit level basis that allows for discrimination of the individual bits of a symbol. Whereas prior art approaches typically perform decoding on a symbol level basis, this decoding approach allows for an improved approach in which the hard decisions/best estimates may be made individually for each of the individual bits of an information symbol. In addition, the decoding approach allows for a reduction in the total number of calculations that need to be performed as well as the total number of values that need to be stored during the iterative decoding. The bit level decoding approach is also able to decode a signal whose code rate and/or signal constellation type (and mapping) may vary on a symbol by symbol basis.
摘要:
A method for asymmetrical MIMO wireless communication begins by determining a number of transmission antennas for the asymmetrical MIMO wireless communication. The method continues by determining a number of reception antennas for the asymmetrical MIMO wireless communication. The method continues by, when the number of transmission antennas exceeds the number of reception antennas, using spatial time block coding for the asymmetrical MIMO wireless communication. The method continues by, when the number of transmission antennas does not exceed the number of reception antennas, using spatial multiplexing for the asymmetrical MIMO wireless communication.
摘要:
LDPC (Low Density Parity Check) codes with corresponding parity check matrices selectively constructed with CSI (Cyclic Shifted Identity) and null sub-matrices. An LDPC matrix corresponding to an LDPC code is employed within a communication device to encode and/or decode coded signals for use in any of a number of communication systems. The LDPC matrix is composed of a number of sub-matrices and may be partitioned into a left hand side matrix and a right hand side matrix. The right hand side matrix may include two sub-matrix diagonals therein that are composed entirely of CSI (Cyclic Shifted Identity) sub-matrices; one of these two sub-matrix diagonals is located on the center sub-matrix diagonal and the other is located just to the left thereof. All other sub-matrices of the right hand side matrix may be null sub-matrices (i.e., all elements therein are values of zero “0”).
摘要:
A wireless local area network (WLAN) transmitter includes a MAC module, a PLCP module, and a PMD module. The Medium Access Control (MAC) module is operably coupled to convert a MAC Service Data Unit (MSDU) into a MAC Protocol Data Unit (MPDU) in accordance with a WLAN protocol. The Physical Layer Convergence Procedure (PLCP) Module is operably coupled to convert the MPDU into a PLCP Protocol Data Unit (PPDU) in accordance with the WLAN protocol. The Physical Medium Dependent (PMD) module is operably coupled to convert the PPDU into a plurality of radio frequency (RF) signals in accordance with one of a plurality of operating modes of the WLAN protocol, wherein the plurality of operating modes includes multiple input and multiple output combinations.