Enhancing the Performance of Multicarrier Delay Diversity Modulation Systems Using Alamouti Codes

This paper investigates the performance of multicarrier delay diversity modulation (MDDM) systems with both cyclic delay diversity and Alamouti space time code techniques and compare its performance with conventional MDDM systems. Deploying Alamouti space time code can allow cost efficient and flexible system deployment compared to classical MDDM system with multiple cyclic delays. In this paper, we propose MDDM system with both cyclic delay and Alamouti codes. The performance of the proposed MDDM system is mathematically illustrated and modeled. The received signals at MDDM receiver are mathematically derived and analyzed. The minimum mean square error (MMSE) and QR decomposition M-algorithm maximum likelihood detection (QRM-MLD) techniques for signal detection is mathematically analyzed and applied to the proposed MDDM system. The performance of the proposed MDDM system is evaluated by simulating the BER for a certain range of SNRs. The BER is calculated for the proposed and classical MDDM systems to investigate the effect of cyclic delay with Alamouti codes in MDDM techniques. Finally, simulation results demonstrate that the proposed MDDM system with QRM-MLD technique enhances the performance of classical MDDM system and gives low values of BER compared with the classical case.