Downlink Capacity Enhancement in GSM System Using Multiple Beam Smart Antenna and SWR Implementation

Abstract

Third-generation (3G) wireless systems need strategies to further improve performance, increase data rates and at the same time provide flexible and affordable support for multi-services and multi-standards. Software radio technology is promising to provide the required flexibility in radio frequency (RF), intermediate frequency (IF) and baseband signal processing stages. Smart antenna can greatly improve system performance, enhance system capacity by making use of spatial processing, exploiting the spatial directivity and reducing co-channel interference. This paper addresses the downlink capacity gain of the multiple beam smart antennas in GSM link Frequency Hopping (FH)-TDMA system. The system capacity is studied. Analytical results are compared with the sectorization-only application. Perfect power control and discontinuous transmission (using voice activity) are taken into consideration in the analysis. One possible software radio architecture for a base station with smart antenna is proposed. In this architecture, smart antenna algorithms might be dynamically reconfigured according to different environment requirements and the baseband processing might also be dynamically reconfigured according to different standard requirements. In this way, the need for flexibility is satisfied.