Research on Nonbinary LDPC-OTFS Scheme in High Mobile Communication Scenarios

The high mobility scenarios supported by B5G/6G, such as high-speed trains and satellite communications, etc., which will produce large Doppler shifts, resulting in a sharp deterioration of communication performance. In response to the demand for higher spectrum and power efficiency, as well as higher reliability and lower latency specifications for future communications, the paper investigates a nonbinary LDPC-OTFS coding and modulation scheme for high mobility scenarios. First, a layered min-max decoding algorithm based on the early termination criterion is studied to further improve the decoding performance and reduce the decoding complexity. Then the novel OTFS modulation technique is analyzed to overcome the malignant effect of large Doppler shift on the communication system and improve the spectral efficiency. Finally, a nonbinary LDPC-OTFS link scheme is built to simulate and analyze the BER performance under different scenarios. The results show that the proposed scheme has better performance and robustness compared to the 5G NR LDPC-OFDM scheme.