本文研究放大转发MIMO中继系统的天线选择,目标是最大化系统容量.针对最优天线选择算法的高复杂度,本文提出了低复杂度且性能逼近最优的快速天线选择算法.首先对MIMO中继系统容量进行了分析和仿真,结果表明:若源的天线数为M、目标的天线数为N,中继从K根天线中选择min(M,N)根就可保证系统达到近似最优的性能.在此基础上,本文以优化容量下界为目标,利用分块矩阵的性质,推导出快速天线选择算法,并分析了算法的复杂度.研究结果表明本文提出的快速天线选择算法的性能与最优算法非常接近,并且有更低的复杂度.
This paper considers antenna selection in the amplify-and-forward multiple-input multiple-output(MIMO) relay systems to maximize the capacity.Since the optimal antenna selection algorithm is of high complexity,a fast antenna selection algorithm is proposed.Through theoretical analysis and simulation,it is shown that if the source and destination have M and N antennas respectively,the relay only needs to use min(M,N) out of K antennas to achieve near optimal performance.The antenna selection criterion of the proposed algorithm is to maximize a lower bound of the capacity.This criterion reduces algorithmic complexity.This paper shows the derivation of the algorithm in detail,and analyze its complexity.Simulation results show that the proposed algorithm achieves comparable performance to the optimal algorithm,and has decreased complexity.