Simple Rateless Codes Based on 5G New Radio QC-LDPC Codes for Dynamic Networks

The fifth telecommunications generation new radio (5G-NR) uses quasi-cyclic low density parity check (QC-LDPC) codes as the channel coding for data transmission, where the codes are based on Raptor coding principle. The advantages of QC-LDPC codes inspire this paper to propose simple and rateless QC-LDPC codes, called simple rateless QC-LDPC (SR-QCLDPC) codes, for dynamic networks communication systems, where simplicity is of importance to minimize the power consumption. Although the coding is simple, the codes should provide high performance coding schemes to support various channel conditions, where a rateless coding scheme is one of the solutions. We design the proposed SR-QC-LDPC codes by removing the high degrees of check nodes and variable nodes in 5G-NR QC-LDPC codes to make the codes are both reduced in size and simpler in computation. We also adjust the fraction of the degree distributions of SR-QC-LDPC codes, evaluate the gap using extrinsic information transfer (EXIT) chart, and investigate the bit-error-rate (BER) performances under additive white Gaussian noise (AWGN) and frequency-flat Rayleigh fading channels using a series of computer simulations. We found that the proposed codes are good and comparable to the performance of original 5G-NR QC-LDPC codes given the equal codes length and complexity.