Distributed space-frequency coding for OFDM-based hybrid relay selection

Cooperative communication in conjunction with orthogonal frequency division multiplexing (OFDM) has recently emerged as a promising technique with the potential to dominate future generations of broadband wireless communications systems. In this paper, we propose an OFDM modulation scheme combined with distributed space-frequency codes (DSFC) based upon a hybrid relay selection protocol. The DSFC process is not required for the amplify-and-forward (AF) relays to reduce the system complexity. Simulation results show that a substantial improvement in bit error rate (BER) performance can be achieved in comparison with conventional relaying protocols. Full rate transmission and diversity order is attainable by this proposed system