抗信道快变的酉空时星座设计

分析了移动台以不同大小速率移动时，信道衰落系数在同一分组长度内的快变性。通过计算机仿真分析发现：酉空时码的误码率随着信道衰落系数自相关函数的减小而恶化，且随分组长度增大而加深恶化。在系统化酉空时星座设计方法的基础上，提出了一种抗信道快变的酉空时星座设计方案。仿真结果表明：该方案可有效地缓解由于信道快变而引起的误码率恶化问题。

Unitary Space-Time Constellation Design Against Channel Rapid Changes

The variation of channel coefficients autocorrelation in a block time is analyzed when the mobile is assumed to travel at different speed and unitary space-time modulation is employed in the communication system. Computer simulation shows the block error rate of unitary space-time modulation increases with the decreasing of autocorrelation of channel coefficients in a block time. Furthermore, the bigger the block is, the worse the block error rate will be. A new method of unitary space-time constellation,which can improve the influence on block error rate by fast fading, is designed based on a systematic method. Simulation experiments show that the block error rate of the new scheme is much lower than that of the old one when the mobile travels at a relatively high speed.