The Cellular Alamouti Technique

Abstract

This paper handles a transmit diversity technique to provide adequate performances at the cell border in a next generation cellular downlink of a mobile communications system. The used technique is based on the Alamouti scheme, and therefore, we call the scheme cellular Alamouti technique (CAT). The CAT is exemplarily applied to an orthogonal frequency division multiplexing access (OFDMA) which is a promising candidate for future communications systems. For improving the performance at the cell borders, the CAT exploits resource management to apply the Alamouti technique and to avoid inter-cellular interference using both adjacent base stations to transmit the desired signal. The influence of the CAT to a cellular OFDMA system is investigated for different resource management strategies. Simulation results show a significant performance improvement at the cell border by using CAT. The performance depends on the resource allocations of the chosen sub-carriers. Nevertheless, CAT is even robust to high-speed scenarios. Furthermore, investigations regarding the system throughput with different modulation alphabets offer a reliable and flexible adaptation to different mobile terminal requests.