多用户MIMO系统中机会波束截断的信道反演

摘要

A novel truncated channel inversion method based on opportunistic beamforming for the MIMO broadcast channel is proposed that allows simultaneous transmission to multiple users.It can obtain the multiuser diversity gain and spatial multiplexing gain with limited feedback from each user.On the basis of channel truncating using opportunistic beamforming, the transmitting power allocation for different users is optimized to make the SINR of each user equal,with the result of improvement of Bit Error Rate(BER) performance.Numerical simulations show that 3~4 Db improvement of the system BER performance is achieved (for 30 users).Channel inversion is more simple than waterfilling power allocation, and it reduces the system complexity.%针对下行链路多用户MIMO系统,提出了一种简单的基于机会波束截断的信道反演方法.机会波束形成可以用最小的反馈获得MIMO系统慢衰落信道中下行链路的多用户分集增益和复用增益.在机会波束形成进行自适应信道截断的基础上,使各通信用户的信干噪比(SINR)相同,改善了系统的误比特率性能.仿真结果表明,总的用户数为30时,系统误比特率性能提高3～4 dB.信道反演比注水功率分配简单,降低了系统复杂度.