Performance Analysis of a Full-Duplex MIMO Decode-and-Forward Relay System With Self-Energy Recycling

This paper analyzes the performance of the full-duplex (FD) multiple-input-multiple-output (MIMO) decode-and-forward (DF) relay system in the presence of self-energy recycling (S-ER). Specifically, this work proposes an antenna allocation scheme for S-ER as well as analytically evaluates the performance of this proposed scheme in terms of spectral efficiency (SE), energy efficiency (EE), outage and symbol error rate (SER). Since, the self-interference (SI) is a major bottleneck in achieving the true potentials of FD communication, this work considers SI as an energy harvesting opportunity to enhance the EE of the system. The proposed analysis shows that reserving few antennas for S-ER at the FD-MIMO relay improves the EE, however, it reduces the antenna array gain at the relay for information transmission and reception. Thus, a slight degradation in the SE, outage and SER is observed. Further, an adaptive S-ER technique has been proposed which utilizes the antennas corresponding to the least channel gain with respect to information transmission and reception for S-ER. This adaptive S-ER technique improves the EE and also compensates for the slight degradation in the SE, outage and SER through adaptive antenna allocation. Closed-form expressions for the SE, EE, outage and symbol error rate have been derived for these S-ER techniques. In the end, simulations results are provided to validate the efficacy of the theoretical derivations.