TY - JOUR
T1 - Joint Source-Relay Design for Full-Duplex MIMO AF Relay Systems
AU - Shi, Qingjiang
AU - Hong, Mingyi
AU - Gao, Xiqi
AU - Song, Enbin
AU - Cai, Yunlong
AU - Xu, Weiqiang
N1 - Publisher Copyright:
© 1991-2012 IEEE.
PY - 2016/12/1
Y1 - 2016/12/1
N2 - The performance of full-duplex (FD) relay systems can be greatly impacted by the self-interference (SI) at relays. By exploiting multiple antennas, the spectral efficiency of FD relay systems can be enhanced through spatial SI mitigation. This paper studies joint source transmit beamforming and relay processing to achieve rate maximization for FD multiple-input-multiple-output (MIMO) amplify-and-forward (AF) relay systems with consideration of relay processing delay. The problem is difficult to solve mainly due to the SI constraint induced by the relay processing delay. In this paper, we first present a sufficient condition under which the relay amplification matrix has rank-one structure. Then, for the case of rank-one amplification matrix, the rate maximization problem is equivalently simplified into an unconstrained problem that can be locally solved using the gradient ascent method. Next, we propose a penalty-based algorithmic framework, named P-BSUM, for a class of constrained optimization problems that have difficult equality constraints in addition to some convex constraints. By rewriting the rate maximization problem with a set of auxiliary variables, we apply the P-BSUM algorithm to the rate maximization problem in the general case. Finally, numerical results validate the efficiency of the proposed algorithms and show that the joint source-relay design approach under the rankone assumption could be strictly suboptimal as compared to the P-BSUM-based joint source-relay design approach.
AB - The performance of full-duplex (FD) relay systems can be greatly impacted by the self-interference (SI) at relays. By exploiting multiple antennas, the spectral efficiency of FD relay systems can be enhanced through spatial SI mitigation. This paper studies joint source transmit beamforming and relay processing to achieve rate maximization for FD multiple-input-multiple-output (MIMO) amplify-and-forward (AF) relay systems with consideration of relay processing delay. The problem is difficult to solve mainly due to the SI constraint induced by the relay processing delay. In this paper, we first present a sufficient condition under which the relay amplification matrix has rank-one structure. Then, for the case of rank-one amplification matrix, the rate maximization problem is equivalently simplified into an unconstrained problem that can be locally solved using the gradient ascent method. Next, we propose a penalty-based algorithmic framework, named P-BSUM, for a class of constrained optimization problems that have difficult equality constraints in addition to some convex constraints. By rewriting the rate maximization problem with a set of auxiliary variables, we apply the P-BSUM algorithm to the rate maximization problem in the general case. Finally, numerical results validate the efficiency of the proposed algorithms and show that the joint source-relay design approach under the rankone assumption could be strictly suboptimal as compared to the P-BSUM-based joint source-relay design approach.
KW - BSUM
KW - MIMO
KW - full-duplex relaying
KW - joint source-relay design
KW - penalty method
UR - http://www.scopus.com/inward/record.url?scp=85027027255&partnerID=8YFLogxK
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U2 - 10.1109/TSP.2016.2605074
DO - 10.1109/TSP.2016.2605074
M3 - Article
AN - SCOPUS:85027027255
SN - 1053-587X
VL - 64
SP - 6118
EP - 6131
JO - IEEE Transactions on Signal Processing
JF - IEEE Transactions on Signal Processing
IS - 23
ER -