We consider a multiuser communication scenario where transmit antenna selection (TAS) is employed at the transmit side and maximal-ratio combining (MRC) is applied at the receive end. In each training period, every user sends a 1-bit feedback (FB) to the transmitter and one user is accordingly scheduled at the transmitter. Subsequently, a single transmit antenna is activated based on a low-rate FB from the scheduled user to the transmitter. We adopt a slow flat fading channel scenario with uncorrelated transmit antennas and correlated receive antennas at each user. First, a general error probability expression applicable to any fading and correlation model with homogeneous users is introduced. Assuming that all the users experience the same exponential correlation structure under Rayleigh and Nakagami-m fading models, we then provide closed-form expressions on bit (symbol) error probability under frequently used modulation schemes. A threshold optimization is performed for the user scheduling process. The inspected low-rate FB scheme is shown to yield an error performance similar to that of a multiuser TAS/MRC technique with analog FB.

我们考虑了一种多用户通信方案，其中在发射端采用发射天线选择（TAS），在接收端采用最大比合并（MRC）。在每个训练周期中，每个用户向发送器发送一个1位反馈（FB），因此在发送器处安排了一个用户。随后，基于从调度用户到发射机的低速率FB激活单个发射天线。我们采用慢平衰落信道方案，在每个用户处具有不相关的发射天线和相关的接收天线。首先，介绍了适用于具有均质用户的任何衰落和相关模型的一般错误概率表达式。假设所有用户在Rayleigh和Nakagami-m衰落模型下都经历相同的指数相关结构，然后，我们在常用的调制方案下提供有关误码率（符号）概率的闭式表达式。为用户调度过程执行阈值优化。所检查的低速率FB方案显示出类似于具有模拟FB的多用户TAS / MRC技术的错误性能。