SCMA-LDPC coded communication system

Abstract

Non-orthogonal multiple access (NOMA) methods are a promising technology that can be the basis of the next generation communication networks and ensure their high throughput. One of the most effective NOMA methods is sparse code multiple access (SCMA). SCMA allows providing better noise immunity and connecting a larger number of subscribers compared to classical solutions used in modern networks. Together with modulation and multiple access, it is reasonable to consider noise-resistant coding procedures that equally affect communication characteristics. One of the most efficient types of noise-resistant codes is low density parity check (LDPC) codes. Now LDPC is used in a number of communication systems, including 5G NR. In this paper, we propose the concept of a communication system with the joint use of LDPC and SCMA. We introduce a sequence of algorithms for the generation and processing of signals. The dependencies of bit error rate (BER) performance on SNR are given: they show the efficiency of the proposed solutions and the ability of the considered communication system to work in various conditions. The results obtained can be used to form a modulation and code scheme (MCS) table for next-generation communication systems.