Construction and Decoding of Rate-Compatible Globally Coupled LDPC Codes

Abstract EN

This paper presents a family of rate-compatible (RC) globally coupled low-density parity-check (GC-LDPC) codes, which is constructed by combining algebraic construction method and graph extension.

Specifically, the highest rate code is constructed using the algebraic method and the codes of lower rates are formed by successively extending the graph of the higher rate codes.

The proposed rate-compatible codes provide more flexibility in code rate and guarantee the structural property of algebraic construction.

It is confirmed, by numerical simulations over the AWGN channel, that the proposed codes have better performances than their counterpart GC-LDPC codes formed by the classical method and exhibit an approximately uniform gap to the capacity over a wide range of rates.

Furthermore, a modified two-phase local/global iterative decoding scheme for GC-LDPC codes is proposed.

Numerical results show that the proposed decoding scheme can reduce the unnecessary cost of local decoder at low and moderate SNRs, without any increase in the number of decoding iterations in the global decoder at high SNRs.