Downlink performance of distributed antenna systems in multicell environment

In this study, the authors investigate the downlink performance of distributed antenna systems (DAS) in multicell environment with blanket transmission. In most existing works, the interference plus noise is treated as Gaussian random variable with fixed variance by the central limit theorem. However, doing this will ignore the effect of the short-term fading on interference that is called as restrictive condition. To avoid the restrictive condition, the authors consider the variance of interference plus noise as a random variable with changeable variance that is influenced by the short-term fading when propagation pathloss and transmit power are given. From the perspective of information theoretic, the closed-form and approximate analytical expressions of downlink achievable throughput, outage probability and average bit error rate in the cellular system are derived for no-shadowing and shadowing scenarios, respectively. Extensive simulation results validate the theoretical analysis and demonstrate that the system performances can be significantly improved for cell-edge users. Moreover, the proposed analytical method can obtain more accurate system performances.