Li Shibao, He Chang, Wang Yixin, Zhang Yang, Liu Jianhang, Huang Tingpei
College of Computer and Communication Engineering, China University of Petroleum (East China), Qingdao 266580, China.
Sensors (Basel). 2017 Mar 10;17(3):563. doi: 10.3390/s17030563.
It is necessary to improve the energy efficiency of batteries in wireless sensor networks (WSNs). The multiple-input multiple-output (MIMO) technique has become an important means to ameliorate WSNs, and interference management is the core of improving energy efficiency. A promising approach is interference alignment (IA), which effectively reduces the interference and improves the throughput of a system in the MIMO interference channels. However, the IA scheme requires perfect channel state information (CSI) at all transceivers in practice, which results in considerable feedback overhead. Thus, limited IA feedback has attracted much attention. In this paper, we analyze the throughput loss of the K-user MIMO interference channels when each transmitter delivers multiple streams in one slot, and derives the upper-bound of the system interference leakage and throughput loss. Then, to reduce the interference leakage and throughput loss for the MIMO interference alignment with limited feedback, a joint power and feedback bit allocation optimization scheme is proposed. The simulation results show that, compared with the conventional schemes, the presented optimal scheme achieves less residual interference and better performance in the system throughput.
提高无线传感器网络（WSN）中电池的能量效率很有必要。多输入多输出（MIMO）技术已成为改善WSN的重要手段，而干扰管理是提高能量效率的核心。一种很有前景的方法是干扰对齐（IA），它能有效降低干扰并提高MIMO干扰信道中系统的吞吐量。然而，IA方案在实际中要求所有收发器都有完美的信道状态信息（CSI），这会导致可观的反馈开销。因此，有限的IA反馈受到了广泛关注。在本文中，我们分析了K用户MIMO干扰信道在每个发射机在一个时隙中发送多个流时的吞吐量损失，并推导了系统干扰泄漏和吞吐量损失的上限。然后，为了减少有限反馈下MIMO干扰对齐的干扰泄漏和吞吐量损失，提出了一种联合功率和反馈比特分配优化方案。仿真结果表明，与传统方案相比，所提出的最优方案在系统吞吐量方面实现了更少的残余干扰和更好的性能。
