发送天线选择对MIMO系统性能的影响

Transmit antennas selection influence on performance of MIMO systems

提出一种在接收端结合最大比合并的发送天线选择新算法。该算法中,发送端从N个可用天线中选择信道增益最佳的L个天线,而接收端不进行天线选择并进行最大比合并。并对该算法在准静态瑞利衰落信道的成对差错性能进行了深入地分析。理论分析和仿真试验证明了尽管发送端天线选择对MIMO系统的分级阶数会造成一定程度的损伤,但同不进行天线选择(L;M)相比,应用该算法仍能获得较大的分级增益,明显提高了相同频谱效率和相同分集阶数条件下空时码的性能。

In this paper the authors propose a scheme of combining transmit antenna selection and maximal-ratio combining (MRC) at the receiver. In this scheme L antennas are chosen for transmission among all available transmit antennas N and the maximal-ratio combining is performed at the receiver side. The pairwise error probability (PEP) of the scheme is derived in quasi-static Rayleigh fading channels. The analysis and simulation results show that, after selecting L transmit antennas among all N available transmit antennas, though the diversity order is decreased to a certain extent, more diversity can still be obtained with the scheme compared with the case of no antenna selection, i.e. (L;M). And, this scheme significantly outperforms the space-time codes of the same diversity order with the same spectral efficiency.