物联网学报 (Dec 2023)
Uplink assisted downlink channel estimation method of extra-large scale MIMO-OTFS system
Abstract
A low complexity downlink channel estimation method for high-speed mobile scenarios was proposed for the extra-large scale multiple-input multiple-output (MIMO) orthogonal time-frequency space (OTFS) system.Different from the existing studies, the proposed method considers the significant spatial non-stationary characteristics of extra-large scale MIMO-OTFS system.Based on the visible path region, an enhanced sparse orthogonal matching pursuit (OMP) algorithm with low complexity was proposed, uplink-assisted downlink channel estimation was achieved using the mapping relationship between the uplink and downlink channels in the frequency-division duplex (FDD) mode.Simulation results show that the proposed uplink-assisted downlink channel estimation method can accurately represent the non-stationary of the system, and achieve significant improvement in the channel estimation performance while reducing the computational complexity , and still perform well in high-mobility IoT scenarios.
