Orthogonal Time Frequency Space (OTFS) With Dual-Mode Index Modulation
Hang Zhao, Dongxuan He, Ziqi Kang, Hua Wang
Abstract
Orthogonal time frequency space (OTFS) modulation has been proved to have better bit error rate (BER) performance over orthogonal frequency division multiplexing (OFDM) under high-mobility conditions. In this letter, a new transmission scheme, called OTFS with dual-mode index modulation (OTFS-DM-IM), is proposed to balance the transmission reliability and spectral efficiency. Moreover, a modified log-likelihood ratio (LLR) detector based on the minimum Hamming distance is designed for demodulation. Then, the theoretical BER analysis of the proposed OTFS-DM-IM is presented. Simulation results highlight the performance advantage of OTFS-DM-IM over classical OTFS and the existing OTFS systems based on index modulation (OTFS-IM), and also confirm the superiority of the modified LLR detector compared to maximum likelihood detector and conventional LLR detector.