改善系统中断速率的一种新虚拟接收天线方案

A New Virtual Receiving Antenna Scheme for Improving Outage Rate

在发射分集系统中,使用虚接收天线技术将时间分集转化为虚接收天线分集,以提高信道的秩,可以有效提高系统中断速率,这十分适用于某些需要能够在较低的中断概率下以一定的传输速率进行通信的系统。已有的研究是将同样的数据在两个时隙内重复发送以形成虚接收天线,而这使得传输效率下降了一半。为改善性能,提出了一种新的虚接收天线方案,不再简单地重复发送,而用一个时隙发送前两个时隙数据的和,从而提高传输效率。分析和仿真表明,新方案可以提供与重复发送方案相同的分集阶数,而且相对于重复发送方案,新方案可以更有效地提高系统中断速率,并且遍历容量也相应提高。

The outage rate of transmit diversity systems can be improved by using virtual receiving antenna ettec- tively because the channel rank is increased by translating the time diversity into space diversity with creating virtual receiving antenna. Hence this technique is useful in some communication systems where low outage prob- ability must be maintained for some information rate. The same data are transmitted in two successive slots in the recent work. Thus the bandwidth efficiency is decreased by 1/2. To improve the bandwidth efficiency, a new virtual receiving antenna scheme is proposed. The superposition of the data transmitted in two successive slots is transmitted again in the following slot instead of repeatedly transmitting. Both the theoretical analysis and simu- lation results indicate that the diversity order of this new scheme is the same as that of the scheme employing re- peatedly transmitting and beth the outage rate and the ergodic capacity can be more effectively improved by using this new scheme than by using existent scheme.