时分双工系统波束赋形块长优化

提出了一种优化时分双工系统波束赋形块长的方案。在该系统中，由于上下行链路的 信道互易性，基站可以通过上行导频估计出当前时刻的信道状态信息，从而计算出下一时刻 的发射波束赋形向量或矩阵。当给定归一化导频开销时，不同的波束赋形块长对应不同的上 行信道估计误差和上下行传输时延，进而导致不同的系统性能。以块平均后验信噪比为目标 函数，推导出最优块长，它能同时最大化块平均后验信噪比和块遍历容量(上界)。仿真结果 验证了理论分析的正确性。

Optimization on Beamforming Block Length in TDD Systems

A scheme is proposed to optimize the beamforming block length for time division dup lex (TDD) systems in this paper. In this system, due to the channel reciprocity between uplink and downlink, the transmitter estimates the current c hannel state information (CSI) to generate the beamforming vector/matrix for next transmission. Given normalized uplink pilot overhead, different beamforming block length causes different uplink channel estimation errors and uplink downl ink transmission delay, leading to different system performance. The o ptimal block length is derived aiming the average post SNR (Signal to Noise Rati o) per bloc k. The obtained block length can maximize not only the average post SNR per bloc k but also ergodic capacity (bound). The simulation results confirm the validity of theoretical analysis.