一种改进的PU2RC多模传输方法

摘要

在有限反馈的下行多用户多入多出(Multiuser multiple-input multiple-output,MU-MIMO)系统中,系统的和容量随着信噪比的升高而干扰受限.本文针对这个问题提出了一种改进的每用户归一化波束成形与速率控制(Per-user unitary beamforming and rate control,PU2RC)多模传输方案,通过增加信道量化质量指示的反馈,为基站进行用户选择提供了更有效的信息以实现多模传输.仿真结果表明,在实际系统中激活用户数比较少时,该方案能够通过动态改变同时服务的用户数,从而最大化系统的和容量.在同等反馈量的情况下,与传统的PU2RC相比,提高了系统的和容量,为下行MU-MIMO系统的应用提供了更好的参考.%In the downlink multiuser multiple-input multiple-output (MU-MIMO) system with limited feedback, the system performance becomes interference power limited in the high SNR regime. Therefore, an improved per-user unitary beamforming and rate control (PU2RC) mul ti-mode transmission scheme is proposed. Channel quantization quality indicator is feedback to the base station (BS), and the corresponding mode selection method is provided. Simulation result shows that in a practical system with small number of active users, the proposed scheme can adaptively choose the best transmission mode to maximize the sum rate of the system. With the identical amount of feedback bits, the proposed multi-mode transmission scheme outper forms the traditional PU2RC scheme and provides better reference for the application of practi cal MU-MIMO systems.