Energy efficiency optimisation in full-duplex relay systems

Energy efficiency of relay communications has attracted much interest recently. Most research efforts have focused on half-duplex systems. As there has been significant progress in practical implementation of self-interference cancellation, full-duplex systems will have a promising potential in the near future. In this letter, energy efficiency of a full-duplex relay system under the total power constraint and fixed circuitry power consumption is studied. An optimisation problem is formulated towards maximising the system energy efficiency. Unfortunately, this problem is non-trivial and cannot be solved by conventional fractional programming methods, such as the Dinkelbach's method. To resolve this issue, an algorithm called sequential parametric convex approximation-Dinkelbach is proposed in this letter. Simulation results show that the proposed algorithm can converge to the global optimum very quickly.