3D-IPRDSOMP Algorithm for Channel Estimation in Massive MIMO With OTFS Modulation

In this paper, we propose a channel estimation method for massive multi-input multi-output (MIMO) with orthogonal time frequency space (OTFS) modulation. Our method aims to reduce inter-symbol interference (ISI) when the subtraction of the two delay paths is smaller than the resolution of the system. We propose a 3D inner product proportion reduce difference structured orthogonal matching pursuit (3D-IPRDSOMP) algorithm that combines the characteristics of 3D structured sparse channels. With knowledge of the number of dominant paths, we use the number of local optimums to match the number of distinguishable dominant paths with backtracking. The algorithm approximates similar and indistinguishable dominant paths as identical ones. The estimated number of distinguishable paths as the iteration’s termination condition increases the channel estimation’s accuracy. Simulation results show better performance than the traditional algorithm under different conditions.