复合衰落信道下分布式MIMO系统中断概率及信道容量分析

针对分布式MIMO系统中断概率和信道容量这2大性能指标,在复合衰落信道模型下,当上行链路采用最大比发送—选择合并,下行链路采用选择发送—最大比合并时,利用Lognormal分布对复杂Gamma-Lognormal分布的近似,推导得到当移动台位置给定时,系统中断概率和信道容量的闭合表达式,证明了系统性能指标与移动台分布之间存在密切的联系;随后依照实际通信环境,提出一种考虑存在小区热点的移动台非均匀分布模型,然后推导得到考虑该分布模型后的系统平均中断概率和平均信道容量闭合表达式;最后通过计算机仿真,证明了所提近似处理的精确性以及各项理论分析的合理性。

Outage probability and capacity analysis of distributed MIMOsystems over a composite fading channel

The exact closed-form expressions about the outage probability and capacity of distributed MIMO systems over a composite fading channel are derived firstly by using Lognormal approximation to complicated Gamma-lognormal distribution when mobile station (MS) in the cell is fixed at some position and the so-called maximum ratio transmis-sion/selected combining (MRT-SC) and selected transmission/maximum ratio combining (ST-MRC) schemes are adopted in uplink and downlink respectively. Then based on a newly proposed non-uniform MS cell distribution model, which is more consistent with the MS cell hotspot distribution in an actual communication environment, the average outage probability and capacity formulas synthesizing the MS cell position information are further derived. Finally, the accuracy of the approximation method and the rationality of the corresponding theoretical analysis about the system performance are proven and illustrated by computer simulations.