Distributed one bit feedback extended orthogonal space time coding based on selection of cyclic rotation for cooperative relay networks

In this paper, a novel closed-loop distributed extended orthogonal space time block code (D-EO-STBC) with one-bit feedback based on selection of phase rotation is proposed for two relay nodes each relay equipped with two antennas. In this scheme, only one-bit of feedback is used to determine the transmission phase terms applied to the symbols from the antennas of each relay nodes. This is considerably lower feedback overhead than previous feedback schemes. This feedback information is based upon channel state information (CSI) available at the destination node. In addition, the transmission rate over each hop in the network is unity and full cooperative diversity is obtained by the approach. Furthermore, this proposed scheme is applied to asynchronous relay networks using orthogonal frequency division multiplexing (OFDM) with cyclic prefix (CP) at the source node to combat the timing error at relay nodes, which operate in a simple distributed STBC mode. End-to-end bit error rate (BER) simulation results show that the proposed scheme can enhance the performance of the system with feedback limited to only one-bit and outperform previous feedback methods.