Energy Efficiency of Full-Duplex Two-Way Channels

This paper studies the energy efficiency (EE) of two-way channels operating in the full-duplex (FD) mode. The residual self-interference (RSI) and self-interference cancellation (SIC) power are modeled as linear functions over the transmission power. The EE maximization problem for the considered FD mode with individual spectral efficiency (SE) constraint is formulated, and the corresponding optimal power allocation is derived by using fractional programming. Then, we further maximize the EE with sum SE constraint and the closed-form expression of this maximum EE is derived. Somehow surprisingly, numerical results show that the FD mode beats the half-duplex (HD) mode when the distance between the two transceivers is relatively large.