Minimum distance of space-division-multiple-access channels

Space-division-multiple-access (SDMA) systems (Balaban and Salz, 1992; Xu et al., 1994, and Liu, 1995) which exploit the spatial diversity among different users has been shown to be effective in solving some key problems in wireless communication systems. However, there is little quantitative measure of the SDMA performance. In this submission, we look at this problem from a fundamental point of view, i.e., the minimum distance of the constellation for SDMA channels since the minimum distance determines bit error rate. Using the minimum distance measure, we can quantify the performance enhancement of the SDMA approach including capacity increase and quality improvement. In particular, we evaluate the minimum distance of SDMA channels in different scenarios, i.e., different number of antennas, co-channel signals and relative user positions