Capacity analysis of downlink MRT-SC in distributed antenna system

This paper investigates the downlink capacity of maximal ratio transmission-selection combining (MRT-SC) in the distributed antenna system (DAS). Composite fading channels are assumed, which include path loss, lognormal shadowing and multi-path Rayleigh fading. Analytical approximation of the capacity´s cumulative distribution function (CDF) is derived by means of a moment generation function (MGF) based approach. The influence of transmit/receive antenna number on the capacity distribution and the impact of receiver location on the 10% outage capacity are investigated. Simulation results agree with the analytical approximations well. Furthermore, it shows that the 10% outage capacity of MRT-SC presents an approximately uniform distribution over most of the interested area, and its value is almost the same with maximal ratio transmission-maximal ratio combining (MRT-MRC).