Downlink transmission capacity analysis for virtual cell based distributed antenna systems

摘要

Distributed antenna systems (DAS) is a promising approach to cope with challenges of next generation mobile communications. This paper studies the downlink ergodic capacity of a (N, K), (K ≤ N), virtual cell based DAS, in which each mobile station (MS) selects the N closest antenna ports (APs) to form its virtual cell and the K closest APs will serve the target MS cooperatively with a total transmit power constraint. Using the stochastic geometry, the locations of APs and MSs are modeled as two independent Poisson point processes, respectively. Then, a computationally tractable integral expression is derived for the downlink ergodic capacity of the (N, K) virtual cell based DAS. Numerical results indicate that the cooperation among multiple APs within each virtual cell can improve the downlink ergodic capacity significantly.