相关信道下MIMO信道容量优化算法的研究

该文研究MIMO系统收发端天线采用均匀线阵且放置空间有限,存在相关衰落时信道容量的优化方法。采用规范化信道模型,分析了信道相关性对平均信道容量和最优信号协方差矩阵的影响,推导了最优协方差矩阵的一阶条件;利用Jensen's不等式确定了信道容量的上界,给出了闭式解,并对相关信道下信号的传输模式进行了讨论。仿真结果表明,采用该优化方法,在各种SNR下,其平均容量接近Jensen's上界;得出信道相关程度对信道平均容量的影响依赖于信噪比的结论。

On Capacity Optimization for Correlated MIMO Channels

This paper studies the capacity of a MIMO system with a correlated fading channel under the constrain of fixed space for the two-ring ULA antennas.A canonical channel model and an optimization program are used to analysis the interactions among transmit and receive antennas,the effects of channel correlation on ergodic channel capacity and optimal transmit covariance matrix are also includo ed.The optimal condition for the transmit covariance matrix and Jensen's upbound are derived in it.Simulation shows that the optimization program gives a result which is very close to the Jensen's upbound and reveals the effect of correlation on capacity depending on SNR.