Joint beamforming and time switching designs for energy-constrained cognitive two-way relay networks
Joint beamforming and time switching designs for energy-constrained cognitive two-way relay networks
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DOI：
10.23919/jcc.2020.05.010
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发表时间：
2020-05
影响因子：
4.1
通讯作者：
Meijuan Zhang;Shibing Zhang;Zhihua Bao;Wei Wang;Xiaoge Zhang;Yonghong Chen
中科院分区：
文献类型：
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作者：
Meijuan Zhang;Shibing Zhang;Zhihua Bao;Wei Wang;Xiaoge Zhang;Yonghong Chen
在本文中，我们研究了一个联合波束成形和时间切换（TS）设计的能量受限的认知双向中继（TWR）网络。在网络中，能量受限的次用户（SU）中继采用TS协议从电路供电的主用户（PU）发射机发送的信号中获取能量，然后利用所获取的能量进行信息转发。我们的目标是在PU的数据速率、能量收集和SU中继的发射功率的约束下，最大化SU的和速率。为了确定波束形成矩阵和TS比，我们将原非凸问题解耦为两个子问题，可以通过半定松弛和连续凸优化方法来解决。此外，我们推导出每个子问题的最优解的封闭形式的表达式，这有利于设计一个次优的迭代算法来处理原来的和率最大化问题。仿真结果表明，与文献中的其他传统方案相比，所提出的联合设计的有效性和上级性能。
In this paper, we investigate a joint beamforming and time switching (TS) design for an energy-constrained cognitive two-way relay (TWR) network. In the network, the energy-constrained secondary user (SU) relay employs TS protocol to harvest energy from the signals sent by the circuit-powered primary user (PU) transmitter, and then exploits the harvested energy to perform information forwarding. Our aim is to maximize the sum rate of SUs under the constraints of the data rate of PU, the energy harvesting and the transmit power of the SU relay. To determine the beamforming matrix and TS ratio, we decouple the original non-convex problem into two subproblems which can be solved by semidefinite relaxation and successive convex optimization methods. Furthermore, we derive closed form expressions of the optimal solutions for each subproblem, which facilitates the design of a suboptimal iterative algorithm to handle the original sum rate maximization problem. Simulation results are presented to illustrate the effectiveness and superior performance of the proposed joint design against other conventional schemes in the literature.