全双工无线携能通信速率最大化波束赋形研究

Sum-rate maximization based beamforming design for full-duplex SWIPT systems

针对全双工无线携能通信系统,提出了一种基于系统和速率最大化准则的波束赋形联合优化方案。该方案以系统和速率最大化为目标,在保证上行/下行链路的最大发射功率约束及最小能量收获需求的同时,实现了信息速率和频谱效率的同步改善。由于速率问题为非凸问题,首先采用半定松弛及一阶泰勒近似方法将其转换为凸优化问题,然后结合基于逐次凸近似的迭代算法分别求解最优的信息波束赋形矢量和能量波束赋形矢量。仿真结果表明,所提方案相比传统方案性能更优,实现了系统和速率的有效提高。

We propsoe a joint optimization scheme of the beamforming vectors based on the maximi zation of system sum rate for the SWIPT communication systems with full-duplex （FD） base station. The proposed scheme makes an improvement in information transmission rate and spectrum efficiency （SE） with the aim of maximizing the system and rate while guaranteeing the maximum transmitting power constraints in the uplinks/downlinks and meeting the minimum energy harvesting requirement. Because the problem of rate is non-convex, we firstly transform the original problem to a convex one via the techniques of semi-definite relaxation （SDR） and first-order Taylor approximation, and then obatain the optimal information beamforming vectors and energy beamforming vectors by the iterative algorithm based on successive convex approximation （SCA）. Simulation results show that the proposed scheme outperforms the traditional schemes, and effectively improves the system sum rate.