A novel method for performance analysis of SDMA

Space division multiple access (SDMA) is recognized to increase the capacity of cellular communication systems greatly and has been a hot research topic for years. Some studies have shown the performance improvement of SDMA in mobile communication environments. In these studies, the problem was modeled in the signal propagation domain, and the assignment probability was a key parameter to calculate the blocking probability but could only be obtained through simulation. The simulation can neither compute the assignment probability accurately, nor find out which are the main factors and how they influence the performance criteria. In this paper, an analytical model is proposed to calculate the blocking probability for the SDMA system. With the reuse condition modeled in the angular domain, a numerical expression of the assignment probability is derived for the first time. Simulation results show that the method proposed in this paper is accurate and efficient.