Optimum element arrangement of adaptive base station antennas for SDMA in circular cell

Space-division-multiple-access (SDMA) is a promising candidate for improving the channel capacity in future wireless communication systems. Since the discrimination performance of the user in the spatial domain depends on the array arrangement, an optimum element arrangement for SDMA should be defined. This paper proposes a formula to determine the optimum element arrangement of smart antennas for SDMA systems. The formula is based on spatial correlation. The dependency of the output SINR performance on element arrangements is also evaluated by computer simulation.