Capacity analysis of GSM systems using slow frequency hopping and smart antennas

The use of smart antennas in frequency hopping (FH)-TDMA cellular systems is one of the effective means of enhancing the capacity of cellular radio systems. The capacity of such cellular systems is interference limited and can be enhanced by reducing the cochannel interference through exploiting the directivity of the smart antennas and making use of spatial processing. This paper addresses the capacity gain of smart antennas in FH-TDMA cellular system. We estimate the system capacity analytically and by simulation as well. Multiple switched beam smart antennas with sinc/sup 2/ antenna pattern are utilized in the study. Perfect power control and discontinuous transmission (using voice activity) are assumed in the simulation and in theoretical analysis. The TDMA system is assumed to be GSM-like but the analysis can be easily extended and applied to any other systems that are based on TDMA such as IS-136.