Chained LDPC Codes via Partial Information Coupling and Partial Parity Superposition

This paper presents a new class of chained low-density parity-check (LDPC) codes for the transport block (TB) based transmission protocol, in which a TB consists of multiple code blocks (CBs). The proposed chained LDPC codes are constructed by coupling together all CBs of a TB into a single chain, where partial information bits between every two adjacent LDPC CBs are shared using the partial information coupling (PIC) technique and partial parity bits are superimposed onto the following LDPC CB using the partial superposition (PS) technique, resulting in a PIC-PS-LDPC code. The proposed construction is universal in the sense that it is applicable to any existing LDPC codes including the random LDPC codes and the structured LDPC codes to obtain extra coding gains. More importantly, the proposed PIC-PS-LDPC codes can have encoder/decoder implemented using the structure of the underlying LDPC codes. Numerical results show that the PS technique can further improve the PIC-LDPC codes, and the PIC technique can further improve the PS-LDPC codes. They also show that the proposed PIC-PS-LDPC codes with the 5G New Radio (5G-NR) LDPC codes as the mother codes can yield a coding gain of up to 0.6 dB over the conventional 5G-NR LDPC codes.