Optimal Transmission Scheduling for a Hybrid of Full- and Half-Duplex Relaying

Full-duplex relaying (FDR), i.e., simultaneous transmission and reception using the same frequency channel at a radio relay, can be used to achieve a spectral efficiency higher than that in the case of half-duplex relaying (HDR) if loop-back interference is well-managed. To achieve spectral efficiency that is higher than that achieved when using FDR and HDR separately, an optimal transmission-scheduling scheme for an FDR-HDR hybrid is proposed. The scheme is formulated as an optimization problem. The conditions required to achieve the maximum spectral efficiency are determined analytically. Numerical results confirm that the proposed scheme is superior to FDR and HDR.