Capacity Analysis Based on Using Adaptive Antenna Arrays Jointly Optimized for Trunking and Spatial Efficiency

Cellular systems using adaptive antennas for spatial processing have been shown to provide an increase in capacity. When employing adaptive antennas, the standard approach to achieve capacity gain has been to maximize the link quality between the mobile and base station via optimum combining. This paper presents an alternative optimization approach based on jointly optimizing the adaptive antenna array to maximize the spatial and trunking efficiencies. An upper bound on the joint optimization was formulated to evaluate the capacity. Based on this upper bound, the effect of using adaptive antenna arrays to maximize the trunking efficiency was subsequently an outstanding issue. Monte Carlo simulations, substantiated with theoretical analysis, were used to evaluate this issue. Based on the analysis, utilizing the adaptive antennas to optimize trunking efficiency could increase the capacity by 2 to 4 times.