Time-Domain Interference Cancellation for ALAMOUTI-Coded Cooperative OFDM Systems With Insufficient CP

Orthogonal frequency-division multiplexing (OFDM) transmission has been proposed in the literature for relay nodes to combat the time delays from the relay nodes, where the paths from relay nodes to the destination node are treated as multipaths, and space-time (or frequency) coding is used to achieve spatial (or multipath) diversity. With this approach, when the cyclic prefix (CP) length is less than the time-delay length, interblock interference occurs. In this paper, we consider Alamouti coded OFDM systems in cooperative communications where the CP length may be less than the time delay length. By taking the advantage of the Alamouti code structure, we propose a time-domain interference-cancellation algorithm. Simulation results show that the performance is significantly improved with our newly proposed time-domain interference-cancellation algorithm.