分布式天线系统和速率分析与最大化

Sum rate analysis and maximization in a distributed antenna system

研究分布式天线系统单小区下行传输时的多用户和速率问题,采用复合衰落信道模型,包括路径损耗、阴影衰落和多径衰落.利用基于矩生成函数和高斯-埃尔米特积分的方法推导了多用户遍历和速率的解析表达式,并通过蒙特卡罗仿真验证了解析表达式的正确性.提出一种基于模式搜索的传输模式选择算法以确定最佳传输模式,即分布式天线与移动台之间的配对方式,从而使遍历和速率最大化.提出的传输模式选择算法与基于最小距离的传输模式选择算法相比,可以达到相近的小区平均遍历和速率,而在特定数量分布式天线单元的情况下,前者目标函数的平均计算次数要小于后者.

To analyze the ergodic sum rate of single cell multiuser downlink transmission in a distribu- ted antenna system （DAS） under composite fading channels which include pass loss, shadowing and multipath fading. Analytic expression of the ergodic sum rate was derived through moment generation function （MGF） and Gauss-Hermite integration based method. The accuracy of the derived expression was verified by Monte Carlo simulations. A pattern search based algorithm was proposed to find the optimal transmission mode, i. e. , the pairings of antenna elements and users, which maximize the erg- odic sum rate. The algorithm achieves nearly the same cell average ergodic sum rate as the algorithm based on minimum distance, while the mean number of objective function evaluations is significantly reduced with regard to specific number of distributed antennas.