Integration of smart antennas with software radio

by Wang, Wei

This thesis investigates some important issues involving the smart antenna array and its integration with software radio technology in TDMA cellular systems. 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. The smart antenna is one of the attractive advanced processing techniques used to greatly improve the system performance. With smart antennas, the capacity can be enhanced by making use of spatial processing, exploiting the spatial directivity of the smart antenna and reducing co-channel interference. This paper address two main points: (i) the capacity gain analysis of the smart antenna in GSM-like TDMA systems, (ii) the software radio architecture design for the TDMA system base station with a smart antenna. The multiple beam smart antenna, also known as switched beam antenna, is used in our analysis. Technologies such as frequency hopping (FH), perfect power control (PC) and discontinuous transmission (DTX) are considered in our study. The performance is analyzed and compared with the sectorization-only application. Analytical results are given and can be easily extended and applied to any other TDMA systems such as IS-136 or next generation systems such as UMTS. One software radio architecture for a base station with smart antenna is proposed and analyzed. In this architecture, the smart antenna algorithms can be dynamically reconfigured according to different environment requirements and the baseband processing can also be dynamically reconfigured according to different standard requirements. In this way, the need for flexibility is satisfied. iii