Beamforming design for MIMO full‐duplex SWIPT IoT system under imperfect CSI

Abstract

Abstract This paper proposes a multiple‐input multiple‐output full‐duplex relay Internet of Things system under imperfect channel state information, where the relay uses time switching relaying protocol to harvest energy. Particularly, due to the uncertainty channel circumstance, the self‐interference in full‐duplex relay cannot be eliminated completely. For such a system, a joint source‐relay beamforming optimization problem which maximizes the system achievable rate subject to the transmit power and harvested energy constraints is studied. In light of the intractability of the problem, a singular value decomposition based geometric programming algorithm is investigated. The considered problem is reformulated to a diagonalized form by using singular value decomposition method. Then, the geometric programming algorithm is adopted to obtain the optimal solution for the reformulated problem. Numerical results validate the effectiveness and superiority of the proposed optimization scheme.