Telefonaktiebolaget Lm Ericsson (Publ)

Amirpasha Shirazinia

Mattias Andersson

Sara Sandberg

Yufei W Blankenship

Magnus Malmberg

A system and method for selecting a number of cyclic redundancy check bits in a communication system. In one embodiment, an apparatus operating in a communication system is configured to receive scheduling information from the communication system, and determine an information block length (K) and/or code rate (R) for a code block including a sequence of data bits from the scheduling information. The apparatus is further configured to determine a number of cyclic redundancy check (CRC) bits as a function of the information block length (K) and/or code rate (R) for the code block.

Cyclic redundancy check selection

Methods, systems, and apparatus are provided for encoding code blocks for transmission in a wireless communication system. An example encoding method in a wireless communication system includes determining, for one or more code blocks of a transport block, that at least one of a plurality of criteria is met, wherein the plurality of criteria includes that a coding rate (R) is less than or equal to 1/4 or that a transport block size (TBS) is less than or equal to 3824 bits and the R is less than or equal to 2/3. The one or more code blocks are encoded using low-density parity-check (LDPC) base graph 2, wherein a maximum code block size is 3840 bits. The one or more encoded code blocks are transmitted over the wireless network.

Code block segmentation for new radio

According to certain embodiments, a method is provided for fast layered decoding for Low-density Parity-Check (LDPC) codes with a Parity-Check Matrix (PCM) that includes at least a first layer and a second layer. The method includes reading, from a memory, Variable Node (VN) soft information, wherein the VN soft information is associated with a message from a VN to a Check Node (CN) of the second layer of the PCM. A new CN to VN message is calculated from the CN of the second layer of the PCM. New VN soft information is calculated for the VN. The new VN soft information is calculated based on the VN soft information and a new CN to VN message from a CN of the first layer to the VN and an old CN to VN message from the CN of the first layer to the VN such that the updating of new VN soft information is delayed by at least one layer. The fast layered decoding has lower decoding latency and utilizes the decoding hardware more efficiently than standard layered decoding techniques. This may be achieved by keeping the memory access and processing hardware units active simultaneously to avoid excess decoding latency. More specifically, certain embodiments may carry out memory access and computation process simultaneously, without any effort to make the row layers mutually orthogonal to each other. Another technical advantage may be that the proposed decoding algorithm adjusts the LLRs to partially account for deviations from the layered decoding due to non-orthogonal rows.

Systems and methods for fast layered decoding for low-density parity-check (LDPC) codes

Methods, systems, and apparatus are provided for encoding code blocks for transmission in a wireless communication system. An example encoding method in a wireless communication system includes determining, for one or more code blocks of a transport block, that at least one of a plurality of criteria is met, wherein the plurality of criteria includes that a coding rate (R) is less than or equal to &#xbc; or that a transport block size (TBS) is less than or equal to 3824 bits and the R is less than or equal to &#x2154;. The one or more code blocks are encoded using low-density parity-check (LDPC) base graph 2, wherein a maximum code block size is 3840 bits. The one or more encoded code blocks are transmitted over the wireless network.

According to certain embodiments, a wireless transmitter comprises a wireless interface and processing circuitry communicatively coupled to the wireless interface. The processing circuitry is operable to send, via the wireless interface, a transmission comprising a plurality of code blocks and a retransmission comprising at least some of the code blocks of the transmission. To send the retransmission, the processing circuitry rearranges the order of the code blocks such that the order of the code blocks in the retransmission differs from the order of the code blocks in the transmission.

Reordering of code blocks for HARQ retransmission in new radio

According to some embodiments, a method in a wireless transmitter comprises: receiving a plurality of bits for a wireless transmission; determining a maximum code block size for the transmission based on code rate, maximum code word size Nmax, and design parameters of the channel code; segmenting the plurality of bits into one or more code block segments such that no one of the one or more code block segments is larger than the determined maximum code block size; and transmitting the one or more code block segments to a wireless receiver. In particular embodiments, the design parameters of the channel code limit the maximum code block size to Kmax for any code rate. The determined maximum code block size may be limited by code rate and Nmax such that the maximum code block size does not exceed code rate times Nmax.

LDPC code block segmentation

According to some embodiments, a method for use in a wireless transmitter of encoding a transport block comprises, upon determining a code rate for transmitting a transport block is less than or equal to R_threshold (R_threshold is between 1/5 and 1/3), selecting new radio (NR) low-density parity-check (LDPC) base graph 2 for encoding the transport block. The method further comprises encoding the transport block using the selected base graph and transmitting the encoded transport block to a wireless receiver.

According to some embodiments, a method for use in a wireless transmitter of encoding a transport block comprises, upon determining a code rate for transmitting a transport block is less than or equal to R_threshold (R_threshold is between &#x2155; and &#x2153;), selecting new radio (NR) low-density parity-check (LDPC) base graphfor encoding the transport block. Otherwise, the method comprises selecting NR LDPC base graphfor encoding the transport block, unless a transport block size (TBS) of the transport block is less than or equal to a size threshold (X) and a code rate for transmitting the transport block is less than or equal to &#x2154;, in which case the method may comprise selecting base graph. The method further comprises encoding the transport block using the selected base graph and transmitting the encoded transport block to a wireless receiver.

Growing community of inventors

Solna, Sweden

Amirpasha Shirazinia