Low-Complexity Parameter Estimation With Interference Cancellation for OTFS-ISAC Systems

Abstract

Due to the suitability for high-mobility scenarios, orthogonal time frequency space (OTFS) is considered a potential waveform for realizing integrated sensing and communication (ISAC). In this letter, we propose a low-complexity fractional delay and Doppler estimation algorithm based on the orthogonal matching pursuit (OMP) framework. The algorithm complexity is reduced by constructing a dimensionality-reduced observation model and pruning noise grids. Meanwhile, by performing inter-path interference (IPI) decision on the targets, only the parameters in the interfered dimension are corrected, thereby resolving the inter-path interference. Simulation results show that the proposed scheme significantly reduces computational complexity. Meanwhile, in the absence of IPI, the estimation accuracy is comparable to the benchmark algorithms, and in the presence of IPI, the estimation accuracy is significantly superior to the benchmark algorithms.