A constructive interference based cooperative diversity for asynchronous uplink OFDMA

This paper proposes and analyses a new cooperative diversity technique that combines users pairing and interference exploitation for enhancing the performance of asynchronous uplink transmission in OFDMA based systems. As well as achieving a diversity order of two, the proposed technique attains further performance enhancements by exploiting co-channel interference. The impact of the proposed technique on various asynchronous conditions is considered in this paper and the performance is assessed through simulation and mathematical analysis. Combined with an effective interference cancellation technique, it will be shown that the results from both models closely match and demonstrate that a significant performance enhancement is obtained relative to other schemes for OFDMA uplink transmission.