Disclosed are methods and systems for using softbit decoding techniques in retransmission-based networks for error concealment of packets corrupted by bit-errors. The softbit decoding techniques derive softbit information from multiple corrupted hardbits of the retransmitted packet to aid a softbit decoder in decoding the packet. The approach realizes improved error concealment capability while maintaining a simple system architecture. A retransmission softbit module is inserted between a channel decoder used for channel-decoding and demodulating a compressed packet and the softbit decoder. The retransmission softbit module may derive an accumulated softbit packet from multiple corrupted copies of the packet received from the channel decoder, make bit decisions based on the accumulated softbit packet, and derive reliability information for the bit decisions. The bit decisions may be a majority decision packet (MDP) created using a majority voting scheme. The reliability information and the MDP may be provided to the softbit decoder for decoding.

This disclosure provides methods, devices and systems for acknowledgement and retransmission, and more specifically, to methods, devices and systems that enable a secondary wireless channel to provide acknowledgements of data transmitted on a primary wireless channel concurrently with the reception of additional data on the primary wireless channel. In some implementations, a transmitting device may transmit wireless packets including multiple codewords to a receiving device via a first wireless channel. The receiving device may attempt to decode the received codewords based on primary information in the codewords. The receiving device may then transmit to the transmitting device, via a second wireless channel, a codeword acknowledgement that identifies codewords that the receiving device did not successfully decode. The transmitting device may then transmit parity information to the receiving device via the first wireless channel that aids the receiving device in decoding the identified codewords.

A data encoding and decoding method for underwater acoustic networks (UANs) based on an improved online fountain code, including: in a build-up phase, subjecting all original packets to sequential encoding according to their serial numbers to generate and send encoded packets with degree 2; merging k original packets to k/8 connected components with a size of 8; performing random encoding until a largest connected component is successfully decoded; in a completion phase, sending, by a receiver, a feedback packet according to a current decoding graph; according to a feedback packet containing decoding states of all the original packets, sending, by a sender, encoded packets with degree m; and randomly selecting original packets for recursive encoding to generate and send encoded packets with degree 1 or 2; and setting, by the receiver, a threshold to restrict the number of feedback packets.

This application provides a data transmission method, a base station, and a terminal device. The method includes: determining, by a base station, a target base graph in N Raptor-like LDPC base graphs; and sending, by the base station, indication information to a terminal device, where the indication information is used to indicate the terminal device to use the target base graph to perform LDPC encoding and decoding. Based on the foregoing technical solution, the base station may determine a target base graph in a plurality of Raptor-like LDPC base graphs that may be used to perform LDPC encoding and decoding, and indicate the target base graph to the terminal device. Further, for one code rate or one code length, the base station may select different base graphs as required.

Examples pertaining to additional bit freezing for polar coding are described. An apparatus performs polar coding to encode a plurality of input subblocks of information bits, frozen bits and optional cyclic redundancy check (CRC) bits to generate a plurality of subblocks of coded bits. The apparatus then transmits at least some of the subblocks of coded bits. In performing the polar coding, the apparatus additionally freezes one of the plurality of input subblocks corresponding to one of the interleaved plurality of subblocks of coded bits which decreases polarization gain due to puncturing.

A pre-5th-generation (pre-5G) or 5G communication system for supporting higher data rates beyond a 4th-generation (4G) communication system, such as long term evolution (LTE) is provided. A channel encoding method in a communication or broadcasting system includes identifying an input bit size, determining a block size (Z), determining a low density parity check (LDPC) sequence to perform LDPC encoding, and performing the LDPC encoding based on the LDPC sequence and the block size.

The present disclosure relates to a pre-5.sup.th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4.sup.th-Generation (4G) communication system such as Long Term Evolution (LTE). According to various embodiments, a device of a terminal, in a wireless communication system, can comprise at least one processor and at least one transceiver operatively coupled to the at least one processor. The at least one transceiver configured to receive, from a base station, a first signal transmitted using a first beam of the base station and including system information and receive, from the base station, a second signal transmitted using a second beam of the base station and including the system information, and the at least one processor is configured to decode the second signal in combination with the first signal, thereby enabling the system information to be acquired.

A data transmission method and a communications device, the method including: determining, by a first communications device, a target data transmission mode, where the target data transmission mode is used to indicate a quantity of times that the first communications device transmits an encoded-bit combination to a second communications device and an encoded-bit combination transmitted each time, the encoded-bit combination transmitted each time may include one encoded bit sequence or a plurality of encoded bit sequences, where the encoded bit sequence is obtained by encoding all or some of K information bits, and K is a positive integer, and sending, by the first communications device, the encoded-bit combination to the second communications device in the target data transmission mode, and receiving, by the second communications device, the encoded-bit combination sent by the first communications device, and decoding the encoded bit sequence included in the encoded-bit combination.

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 channel encoding method in a communication or broadcasting system is provided. The channel encoding method includes reading a first sequence corresponding to a parity check matrix, converting the first sequence to a second sequence by applying a certain rule to a block size corresponding to a parity check matrix and the first sequence, and encoding information bits based on the second sequence. The block size has at least two different integer values.