A transmitter is provided. The transmitter includes: a Low Density Parity Check (LDPC) encoder configured to encode input bits to generate an LDPC codeword including the input bits and parity bits to be transmitted in a current frame; a parity permutator configured to interleave the parity bits and group-wise interleave a plurality of parity bit groups configuring the interleaved parity bits based on a group-wise interleaving pattern including a first pattern and a second pattern to perform parity permutation; a puncturer configured to puncture at least some of the group-wise interleaved parity bit groups; and an additional parity generator configured to select at least some of the punctured parity bit groups to generate additional parity bits to be transmitted in a previous frame of the current frame, based on the first pattern and the second pattern.

Disclosed is a method for processing code blocks as implemented by a baseband processor. The method involves performing a cyclic redundancy check on decoded and deinterleaved code blocks until one fails its CRC check. On first failure the baseband processor requests a retransmission of the code blocks and resumes CRC checks on the retransmitted code blocks, beginning at the code block that had failed. In the event of subsequent failures, the baseband processor performs a soft combine on the failed retransmitted block with its original transmitted counterpart. Only if the soft combined code block fails does the baseband processor request another retransmission. In this case, subsequent CRC failures result in soft combines of three corresponding code words, making the process more robust. The method reduces the number of retransmissions as well as the computing resources needed for processing incoming code blocks.

Aspects of the present disclosure are directed to ascertaining whether data messages are repetitions of a previous data message. As may be implemented in accordance with one or more embodiments characterized herein, data packets (130/131) are received (102) and which use a first time delay relative to transmission of a previous data packet (120/121) by a different transmitter. Repetitions (110A/111A) of data packets are also received (102), and which use a second time delay relative to transmission of a previous data packet (110/111) by the same transmitter. The second time delay is less than the first time delay. The received packet is identified (102) as being a repetition of an immediately-previous data packet based on a time delay between the data packet and the immediately-previous data packet, relative to the first and second time delays.

Example systems, read channel circuits, data storage devices, and methods to provide signal correction based on soft information in a read channel are described. The read channel circuit includes a soft output detector, such as a soft output Viterbi algorithm (SOVA) detector, and a signal correction circuit. The soft output detector passes detected data bits and corresponding soft information to the signal correction circuit. The signal correction circuit uses the soft information to determine a signal correction value, which is combined with input signal to return a corrected signal to the soft output detector for a next iteration. In some configurations, the signal correction value may compensate for DC offset, AC coupling poles, and/or signal asymmetries to reduce baseline wander in the read channel.

The present disclosure relates to multiple-symbol combination based decoding for general polar codes. Multiple-symbol combination based decoding of a received word that is based on a codeword involves determining whether all nodes at an intermediate stage of the multiple-symbol combination based decoding, which provide their outputs as inputs to a subset of nodes at a next stage of the multi-symbol combination based decoding, are associated with trust symbols in the received word that have a higher reliability of being successfully decoded than doubt symbols in the received word. A hard decision is performed in response to a positive determination.

The present invention related to a 5G or pre-5G communication system to be provided to support a higher data transmission rate since 4G communication systems like LTE. The present invention relates to a method and an apparatus for encoding a channel in a communication or broadcasting system supporting parity-check matrices having various sizes are provided. The method for encoding a channel includes determining a block size of the parity-check matrix; reading a sequence for generating the parity-check matrix, and transforming the sequence by applying a previously defined operation to the sequence based on the determined block size.

A transmitter is provided. The transmitter includes: a Low Density Parity Check (LDPC) encoder configured to encode input bits to generate an LDPC codeword including the input bits and parity bits to be transmitted in a current frame; a parity permutator configured to perform parity-permutation by interleaving the parity bits and group-wise interleaving a plurality of bit groups configuring the interleaved parity bits based on a group-wise interleaving pattern including a first pattern and a second pattern; a puncturer configured to puncture some of the parity-permutated parity bits; and an additional parity generator configured to select at least some of the punctured parity bits to generate additional parity bits to be transmitted in a previous frame of the current frame, based on the first pattern and the second pattern, wherein the first pattern determines parity bits to remain after the puncturing and then to be transmitted in the current frame.

A detection circuit performs a turbo detection process to recover a frame of data symbols from a received signal, the data symbols of the frame having been effected, during transmission, by a Markov process with the effect that the data symbols of the frame in the received signal are dependent one or more preceding data symbols which can be represented as a trellis having a plurality of trellis stages. The detection circuit comprises a plurality of processing elements, each of the processing elements is associated with one of the trellis stages representing the dependency of the data symbols of the frame according to the Markov process and each of the processing elements is configured to receive one or more soft decision values corresponding to one or more data symbols associated with the trellis stage, and each of one or more of the processing elements is configured, in one clock cycle to receive fixed point data representing a priori forward state metrics a priori backward state metrics, and fixed point data representing a priori soft decision values for the one or more data symbols being detected for the trellis stage. For each of a plurality of clock cycles of the turbo detection process, the detection circuit is configured to process, for each of the processing elements representing the trellis stages, the a priori information for the one or more data symbols being detected for the trellis stage associated with the processing element, and to provide the extrinsic soft decision values corresponding to the one or more data symbols for a next clock cycle of the turbo detection process.

Disclosed is a method for processing code blocks as implemented by a baseband processor. The method involves performing a cyclic redundancy check on decoded and deinterleaved code blocks until one fails its CRC check. On first failure the baseband processor requests a retransmission of the code blocks and resumes CRC checks on the retransmitted code blocks, beginning at the code block that had failed. In the event of subsequent failures, the baseband processor performs a soft combine on the failed retransmitted block with its original transmitted counterpart. Only if the soft combined code block fails does the baseband processor request another retransmission. In this case, subsequent CRC failures result in soft combines of three corresponding code words, making the process more robust. The method reduces the number of retransmissions as well as the computing resources needed for processing incoming code blocks.

Wireless communications systems and methods related to wireless communications in a system are provided. A wireless communication device may compute a plurality of log-likelihood ratios (LLRs) based on a received communication signal. At least a first LLR and a second LLR of the plurality of LLRs represent the same first bit in the communication signal. The wireless communication device may combine the first LLR and the second LLR to decode the first bit and transmit a report indicating channel information. The channel information may be based at least in part on the plurality of LLRs before the combining of the first and second LLRs.