针对在无线多输入—多输出(MIMO)通信系统的发射端采用波束成形、接收端采用最大比合并的MI-MO MRC系统,考虑收发端仅能获得存在信道估计误差的非理想信道信息(CSI)且系统受到共信道干扰这一条件,分析系统的多用户分集性能。导出封闭形式的信号干扰噪声比的概率分布函数表达式和以平均容量的形式给出的系统多用户分集性能表达式。数值仿真证实了理论分析的结果。研究表明,信道估计误差和共信道干扰均会降低系统的多用户分集性能,而信道估计的精度是影响系统多用户分集性能的关键因素。
The performance of multiuser diversity in multiple-input multiple-output wireless systems employing transmit beamforming and maximum ratio combining (MIMO MRC) with channel estimation error in the presence of co-channel interferences (CCIs) was analyzed. Exact closed-form cumulative distribution function expression of the signal-to-noise-plus-interference ratio (SINR) was derived. The average capacity of MIMO MRC systems with multiuser diversity was presented. Numerical results demonstrate the accuracy of analytical expressions. Results show that the performance of the average capacity is deteriorated as the power of CCI and the channel estimation error increase. Moreover, the accuracy of the channel estimation is crucial for the multiuser diversity gain.