5G New Radio LDPC Codes Based Generalized Joint Subcarrier-Time Index Modulation DCSK System

Low-Density-Parity-Check (LDPC) codes are a cornerstone for achieving robust error correction capabilities in 5G New Radio applications, significantly improving the reliability of data transmission across noisy and unpredictable wireless channels. Since an evaluation and discussion of the performance with channel coding is significantly absent in two-dimensional Index Modulation (IM)-Differential Chaos Shift Keying (DCSK) schemes. Therefore, in this study, the 5G new radio LDPC codes based generalized joint subcarrier-time index modulation DCSK system (5G NR-LDPC-GJSTIM-DCSK) is proposed, where 5G NR-LDPC codes are used as channel coding. The aim is to improve the system’s performance specifically across AWGN (additive white gaussian noise) and multipath Rayleigh fading channels, when contrasted with the uncoded GJSTIM-DCSK. In the suggested system, the detected index bits at the receiver are transformed into soft bits and combined with the soft demodulated bits before the decoding process. The results show that the highest coding improvements are 11.6 dB for AWGN channels and 22.2 dB for Rayleigh fading channels, using a code rate of 1/5, a codeword length of 7648, and a spreading factor of 256. Additionally, the performance of the 5G NR-LDPCGJSTIM- DCSK system surpasses the 5G NR-LDPC-GSIMDCSK- II’s performance and is nearly equivalent to the 5G NR-LDPC-GFTIM-DCSK-II’s performance at high SNR (Signal to Noise Ratio).