Downlink Performance of Indoor Distributed Antenna Systems Based on Wideband MIMO Measurement at 5.25 GHz

Abstract

Distributed antenna system (DAS) is a very promising technology to enhance the capacity of indoor communication system due to the inherent macro and micro diversity. With its natural characteristics of reducing the access distance and increasing the probability of line-of-sight (LoS) coverage, DAS can greatly enhance the power efficiency, which is in accordance with the goal of green communication. In this paper, the downlink performance of an indoor DAS is investigated based on a realistic wideband multiple input multiple output (MIMO) channel model constructed with measured data at 5.25 GHz. Different transmission schemes and antenna configurations are compared from the capacity point of view. It is demonstrated that with the same total transmit power DAS with selection transmission (ST) can increase the capacity significantly compared with centralized antenna system (CAS) and DAS with equal-power transmission. The results also show that MIMO technique can improve the system performance significantly even under LoS propagation conditions for indoor scenarios, which is counterintuitive to the common sense that MIMO will suffer from great performance degradation under LoS conditions.