Predictor antenna (PA) system is referred to as a system with two sets of antennas on the roof of a vehicle, where the PAs positioned in the front of the vehicle are used to predict the channel state observed by the receive antennas (RAs) that are aligned behind the PAs. This letter studies the performance of PA systems in the presence of the mismatching problem, i.e., when the channel observed by the PA is not exactly the same as the channel experienced by the RA. Particularly, we study the effect of spatial mismatching on the accuracy of channel state information estimation and rate adaption. We derive closed-form expressions for instantaneous throughput, outage probability, and the throughput-optimized rate adaptation. Also, we take the temporal evolution of the channel into account and evaluate the system performance in temporally-correlated conditions. The simulation and analytical results show that, while PA-assisted adaptive rate adaptation leads to considerable performance improvement, the throughput and the outage probability are remarkably affected by the spatial mismatch and temporal correlations.

中文翻译：

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预测天线系统中的速率自适应

预测器天线（PA）系统是指在车顶有两组天线的系统，其中位于车辆前方的PA用于预测接收天线（RA）观察到的信道状态。排列在 PA 后面。这封信研究了存在失配问题时 PA 系统的性能，即当 PA 观察到的信道与 RA 经历的信道不完全相同时。特别地，我们研究了空间失配对信道状态信息估计和速率自适应精度的影响。我们推导出瞬时吞吐量、中断概率和吞吐量优化速率自适应的封闭形式表达式。还，我们考虑了信道的时间演变，并评估了时间相关条件下的系统性能。仿真和分析结果表明，虽然 PA 辅助的自适应速率自适应导致显着的性能改进，但吞吐量和中断概率受到空间失配和时间相关性的显着影响。