Cooperative communication with grouped relays for zero-padding MB-OFDM

The emerging technology of cooperative communication has been intensively examined in the recent years. However, few investigate its combination with the Multi-band (MB) OFDM physical layer. In the paper, we propose a cooperative MB-ODFM communication with efficiently grouped relays under multipath channel. Taking advantage of the multiple bands together with the grouped relays, the proposed zero-padding MB-OFDM is proven to collect the full cooperative diversity only with linear equalizer rather than a Maximum-Likelihood (ML) receiver, and without bandwidth efficiency waste that Alamouti-like codes suffer. Furthermore, the QPSK modulation for Rayleigh channel and the dual carrier modulation for an IEEE Ultra-Wide-Band (UWB) channel are both tested to show that the full cooperative diversity can be gained. Finally, the case with multiple carrier frequency offsets (CFOs) is also discussed.