Cross Domain Iterative Detection for Orthogonal Time Frequency Space Modulation

Recently proposed orthogonal time frequency space (OTFS) modulation has been considered as a promising candidate for accommodating various emerging communication and sensing applications in high-mobility environments. In this paper, we propose novel cross domain iterative detection algorithm to enhance the error performance of OTFS modulation. Different from conventional methods, applies basic estimation/detection approaches both delay-Doppler (DD) iteratively updates extrinsic information two domains with unitary transformation. doing so, exploits channel sparsity DD symbol constellation constraints. We evaluate variance each iteration derive state evolution investigate performance. show that gain due iterations comes non-Gaussian constraint domain. More importantly, prove can indeed converge and, convergence, achieve almost same maximum-likelihood sequence even presence fractional Doppler shifts. Furthermore, computational complexity associated transformation is low, thanks structure discrete Fourier transform (DFT) kernel. Simulation results are consistent our analysis demonstrate significant improvement compared methods.