Subchannel-allocation algorithms and performance analysis for space-time OFDM-CDMA based systems in wireless networks

Both space-time (ST) processing and orthogonal frequency division multiplexing (OFDM) are becoming increasingly important techniques used in physical layer to support the quality of service (QoS) for different applications in wireless networks. However, the employment of such techniques affects the scheme designs at higher layers such as channel allocation algorithms at media access control (MAC) layer. Therefore, a crossing-layer development is required. In this paper, we propose the subchannel allocation algorithms based on space-time OFDM-CDMA systems, and develop the throughput-performance analysis frameworks to evaluate the proposed algorithms. Our analyses show that the proposed subchannel allocation scheme can significantly increase the system throughput over wireless networks, while achieving a much lower implementation and computation complexity as compared to the smart-antenna-based systems. Also presented are the simulation results that verify the analytical findings and observations.