A CP-SC-based two-way multiple-relay system with distributed space-frequency block coding

In this paper, we propose a cyclic prefixed single-carrier (CP-SC)-based two-way multiple-relay system with distributed space-frequency block coding (D-SFBC). Two CP-SC sources exchange the information within two time phases with the aid of multiple relay nodes in the frequency selective fading channels. The D-SFBC is proposed to be implemented across multiple relay nodes, which provides the orthogonal/quasi-orthogonal structure in the space-frequency-domain for the received signals at the terminals. It is shown that the proposed system significantly outperforms the single-relay-node-aided CP-SC system while providing a higher diversity/array gain and a higher average sum-rate. By repeating D-SFBC across the subcarriers, the proposed system also achieves the multi-path diversity available in the frequency-selective fading channels.