Multimode Precoding for Multiuser MIMO Systems With Finite Rate Feedback

Kyeongjun Ko, Yonghee Han, Jungwoo Lee

Abstract: In practical multiuser multiple-input multiple-output (MU-MIMO) systems with limited feedback, inter-user interference cannot be completely suppressed due to the channel state information quantization error, and the residual interference degrades the throughputs. In this letter, we introduce a MU-MIMO system with multimode precoding that adapts the number of served users based on the channel condition to maximize the spectral efficiency. In addition, a mode selection rule and a novel cumulative distribution function-based feedback rule are also developed for the proposed system. Simulation results show that the proposed system provides higher spectral efficiency compared to conventional limited feedback precoding systems.