Quasi-Cyclic Low-Density Parity-Check (QC-LDPC) codes for deep space and high data rate applications

Abstract

In this paper we investigate and compare the performance of a selected class of Low-Density Parity-Check (LDPC) codes, i.e. Quasi-Cyclic (QC) LDPC codes, against the currently used turbo codes for deep space and high data rate applications. This is useful in future updates of the channel code option used for such applications by the Consultative Committee for Space Data Systems (CCSDS). A wide range of different code rates is examined and the obtained Bit Error Rate (BER) performance versus the Bit Energy to Noise Spectral Density ratio (Eb/N0) is reported. Both low and high code rates are being studied, and specifically the 1/2, 1/3, 1/4 and 1/5 as well as the 2/3, 3/4 and 4/5 code rates are taken under consideration. The role of the iteration rounds in the decoding procedure of LDPC codes is also examined showing that QC-LDPC codes outperform the currently used CCSDS turbo codes. Another advantage of QC-LDPC codes is their simple encoding procedure, which reduces the encoding complexity. Since deep space applications are considered, the signals are transmitted over the Additive White Gaussian Noise (AWGN) channel, with the specific block size of 7136 bits.