Energy Efficiency and Power Allocation Optimization in Hardware-Impaired Full-Duplex Access Point

Full-duplex (FD) communications have been recognized as one of the promising wireless transmission candidates for the future of wireless communication and networking technologies, thanks to their ability to greatly improve spectral efficiency (SE) and dramatically enhance energy efficiency (EE). In this paper, we study the influence of hardware impairments (HWIs) on single-input single-output (SISO) FD access point (AP). More precisely, we study the EE when the system's terminals have impaired transceivers. Optimization problem for EE maximization is formulated to fulfill quality of service (QoS) and power budget constraints. We propose an algorithm to solve the optimization problem by using the fractional programming theory and Karush-Kuhn-Tucker (KKT) conditions technique. The results unveil that excellent power allocation is crucial in FD communication networks and the proposed algorithm outperforms the maximum power transmission scheme. The results also reveal that HWIs degrade both EE and SE performance. Moreover, at high power region, no further improvements can be obtained by increasing the transmission power. Finally, we assume that all fading channels demonstrate Nakagami-m distribution.