This paper investigates the simultaneous wireless information and power transfer (SWIPT) precoding scheme for K-user multiple-input-multiple-output (MIMO) interference channels (IC). In IC, interference alignment (IA) schemes provide optimal precoders to achieve full degrees-of-freedom (DoF) gain. To study a trade-off between harvested energy and sum rate, the transceiver design problem is suboptimally formulated in literature via convex relaxations, which is still computationally intensive, especially for battery limited nodes running on harvested energy. In this paper, we propose a systematic method using chordal distance (CD) decomposition to obtain the balanced precoding, which achieves the improved trade-off. Analysis shows that given the nonnegative value of CD, the achieved harvested energy for the proposed precoder is higher than that for perfect IA precoder. Moreover, energy constraints can be achieved, while maintaining a constant rate loss without losing DoFs via tuning the CD value and splitting factor. Simulation results verify the analysis and add that the IA schemes based on max-SINR or mean-squared error are better suited for SWIPT maximization than subspace or leakage minimization methods.
翻译:本文调查了K用户多投入-多输出干扰渠道(IC)的同步无线信息和电源传输预编码(SWIPT)预编码计划(SWIPT),在IC中,干扰调整(IA)计划提供了实现完全自由度收益的最佳预译器。为了研究收获能量和总率之间的权衡,收发器设计问题在文献中通过Convex放松(Convex Referations)进行,这种放松仍然在计算上十分密集,特别是电池有限的节点运行在收获的能源上。在本文中,我们建议采用系统方法,使用Chordal距离(CD)解密(CD)获得平衡的预编码,从而实现更好的交易。分析表明,鉴于CD的非负值,为拟议的预译器所获取的节能高于完美IA前的节率。此外,通过调整CD值和分解系数,可以实现不断的损耗率,同时又不损失DoFs。模拟结果验证了分析,并补充了基于最大升率或最大升温方法的IPIS计划。