摘要:
Bandwidth efficient coded modulation scheme based on MLC (Multi-Level Code) signals having multiple maps. The use of multiple maps is adapted to various types of coded signals including multi-level LDPC coded modulation signals and other MLC signals to provide for a significant performance gain in the continual effort trying to reach towards Shannon's limit. In the instance of LDPC coded signals, various level LDPC codewords are generated from individual corresponding LDPC encoders. These various level LDPC codewords are arranged into a number of sub-blocks. Encoded bits from multiple level LDPC codewords within each of the sub-blocks are arranged to form symbols that are mapped according to at least two modulations. Each modulation includes a constellation shape and a corresponding mapping. This use of multiple mappings provides for improved performance when compared to encoders that employ only a single mapping.
摘要:
Implementation of LDPC (Low Density Parity Check) decoder by sweeping through sub-matrices. A novel approach is presented by which an LDPC coded signal is decoded processing the columns and rows of the individual sub-matrices of the low density parity check matrix corresponding to the LDPC code. The low density parity check matrix can partitioned into rows and columns according to each of the sub-matrices of it, and each of those sub-matrices also includes corresponding rows and columns. For example, when performing bit node processing, the same columns of at 1 or more sub-matrices can be processed together (e.g., all 1st columns in 1 or more sub-matrices, all 2nd columns in 1 or more sub-matrices, etc.). Analogously, when performing check node processing, the same rows of 1 or more sub-matrices can be processed together (e.g., all 1st rows in 1 or more sub-matrices, all 2nd rows in 1 or more sub-matrices, etc.).
摘要:
Sub-matrix-based implementation of LDPC (Low Density Parity Check) decoder. A novel approach is presented by which an LDPC coded signal is decoded by processing 1 sub-matrix at a time. A low density parity check matrix corresponding to the LDPC code includes rows and columns of sub-matrices. For example, when performing bit node processing, 1 or more sub-matrices in a column are processed; when performing check node processing, 1 or more sub-matrices in a row are processed. If desired, when performing bit node processing, the sub-matrices in each column are successively processed together (e.g., all column 1 sub-matrices, all column 2 sub-matrices, etc.). Analogously, when performing check node processing, the sub-matrices in each row can be successively processed together (e.g., all row 1 sub-matrices, all row 2 sub-matrices in row 2, etc.).
摘要:
LDPC (Low Density Parity Check) coding and interleaving implemented in multiple-input-multiple-output (MIMO) communication systems. Initially, a novel approach is presented by which a wide variety of irregular LDPC codes may be generated using GRS or RS codes. These irregular LDPC codes can provide better overall performance than regular LDPC codes in terms of providing for lower BER (Bit Error Rate) as a function of SNR (Signal to Noise Ratio). A variety of communication device types are also presented that may employ the error correcting coding using a GRS-based irregular LDPC code, along with appropriately selected interleaving, to provide for even better performance. These communication devices may be implemented to in wireless communication systems including those that comply with the recommendation practices and standards being developed by the IEEE 802.11n Task Group (i.e., the Task Group that is working to develop a standard for 802.11 TGn (High Throughput)).
摘要:
LDPC (Low Density Parity Check) coded 128 DSQ (Double Square QAM) constellation modulation and its associated labeling. A novel means is introduced by which a constellation may be arranged and mapping in its symbols may be determined to provide for improved performance. One application area in which this may be employed is transmission over twisted pair (typically copper) cabling existent within data centers of various networks. The operation of the IEEE 802.3 Ethernet local area networks currently being used (as well as those currently under development) would benefit greatly by employing the various principles presented herein. When this novel approach of an LDPC coded 128 DSQ constellation modulation combined with TH (Tomlinson-Harashima) preceding is employed within a communication device at a transmitter end of a communication channel (i.e., in a transmitter and/or a transceiver), the overall operation of a communication system may improve significantly when compared to prior techniques.
摘要:
Efficient design to implement min**/min**− or max**/max**− functions in LDPC (Low Density Parity Check) decoders. When compared to prior art approaches, the novel and efficient implementation presented herein allows for the use of substantially less hardware and surface area within an actual communication device implemented to perform these calculations. In certain embodiments, the min** processing (and/or max** processing) is implemented to assist in the computationally intensive calculations required to decoded LDPC coded signals. In one instance, this is operable to assist in check node processing when decoding LDPC coded signals. However, the efficient principles and architectures presented herein may be implemented within other communication device types to decode other types of coded signals as well. For example, the processing presented herein may perform calculations within a variety of decoders including LDPC decoders, turbo decoders, TTCM decoders, and/or other decoder types without departing from the scope and spirit of the invention.
摘要翻译:高效设计实现LDPC(低密度奇偶校验)解码器中的min ** / min ** - 或max ** / max ** - 函数。 当与现有技术方法相比时,本文提出的新颖且有效的实现允许在实现为执行这些计算的实际通信设备中使用实质上更少的硬件和表面积。 在某些实施例中,实现最小**处理(和/或最大**处理)以帮助解码LDPC编码信号所需的计算密集计算。 在一种情况下,这可用于在解码LDPC编码信号时辅助校验节点处理。 然而,本文呈现的有效原理和架构可以在其他通信设备类型内实现,以解码其他类型的编码信号。 例如,在不脱离本发明的范围和精神的情况下,这里呈现的处理可以在包括LDPC解码器,turbo解码器,TTCM解码器和/或其他解码器类型的各种解码器中执行计算。
摘要:
Efficient LDPC code decoding with new minus operator in a finite precision radix system. A new mathematical operator is introduced and applied to the decoding of LDPC coded signals. This new operator is referred to as the min†− (min-dagger minus) operator herein. This min†− processing is appropriately applied during the updating of the edge messages with respect to the variable nodes. In a bit level decoding approach to decoding LDPC coded signals, the updating of the edge messages with respect to the bit nodes is performed using the new min†− operator. This approach provides very comparable performance to min** processing as also applied to updating of the edge messages with respect to the bit nodes and may also provide for a significant savings in hardware. Also, within finite precision radix systems, the new min†− operator provides a means by which always meaningful results may be achieved during the decoding processing.
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:
A method for parallel concatenated (Turbo) encoding and decoding. Turbo encoders receive a sequence of input data tuples and encode them. The input sequence may correspond to a sequence of an original data source, or to an already coded data sequence such as provided by a Reed-Solomon encoder. A turbo encoder generally comprises two or more encoders separated by one or more interleavers. The input data tuples may be interleaved using a modulo scheme in which the interleaving is according to some method (such as block or random interleaving) with the added stipulation that the input tuples may be interleaved only to interleaved positions having the same modulo−N (where N is an integer) as they have in the input data sequence. If all the input tuples are encoded by all encoders then output tuples can be chosen sequentially from the encoders and no tuples will be missed. If the input tuples comprise multiple bits, the bits may be interleaved independently to interleaved positions having the same modulo−N and the same bit position. This may improve the robustness of the code. A first encoder may have no interleaver or all encoders may have interleavers, whether the input tuple bits are interleaved independently or not. Modulo type interleaving also allows decoding in parallel.
摘要:
LDPC (Low Density Parity Check) coded modulation symbol decoding. 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. The iterative decoding processing may involve updating the check nodes as well as estimating the symbol sequence and updating the symbol nodes. In some embodiments, an alternative hybrid decoding approach may be performed such that a combination of bit level and symbol level decoding is performed. This LDPC symbol decoding out-performs bit decoding only. In addition, it provides comparable or better performance of bit decoding involving iterative updating of the associated metrics.