Low‐complexity detection method based on channel matrix periodic N‐diagonal equivalence for uplink MU‐MIMO of multi‐beam satellite communication systems

Abstract

SummaryIn this paper, a low‐complexity detection method for uplink Multi‐User Multiple‐Input Multiple‐Output (MU‐MIMO) of multi‐beam satellite communication systems is studied. Firstly, we derive the uplink receiving system model and give the beam‐domain channel expression. Utilizing the characteristics of energy concentration of uplink channel in beam domain, we propose that the channel matrix can be equivalent to periodic N‐diagonal matrix, which can reduce the number of channel estimations and reduce the computational complexity of detection. Then, based on the beam‐domain channel matrix equivalent model, two low‐complexity minimum mean square error (MMSE) detection methods are proposed to reduce the computational complexity of traditional MMSE detection from to O(K). Simulation results show that the proposed methods have limited performance loss compared with the traditional methods.