Energy Efficiency Enhancement in Full-Duplex Relay System through Adaptive Antenna Allocation

Energy efficiency (EE) is one of the crucial parameter for designing the next generation wireless communication standard. This paper investigates the impact of antenna allocation on the EE of a full-duplex (FD) decode-and-forward (DF) relay system. Further, a scheme based on antenna allocation (AA) is proposed that enhances the EE of the FD relay system. Since the complete mitigation of self-interference (SI) in the FD system is inevitable, the SI impacts the reception at the relay, whereas the transmission from relay is relatively interference-free. The proposed scheme exploits the above and proposes an unequal antenna distribution for transmission and reception at the FD relay, wherein more number of antennas are allocated for information reception as compared to information transmission at the FD relay. The proposed AA scheme also reduces the circuit power consumption by reducing the number of active RF transmit chains at the FD relay. It has been shown that the EE can be further enhanced through adaptive AA, where the antennas are allocated based on channel gain. Good agreement between the analytically obtained expressions and simulation results validates the proposed analysis.