异构网络中D2D终端无线能量收集方案研究

摘要

为保证小区边缘用户(cell edge user,CEU)的通信质量,同时提高系统频谱和能量效率,针对D2D(device-to-device)发射机,提出一种无线能量收集方案.在3层异构网(heterogeneous networks,HetNets)中,基于小区分割因子,将宏小区用户(macrocell user,MU)划分为小区中心用户(cell center user,CCU)和CEU.同时,将频带划分成小区中心区域(cell center region,CCR)频带和小区边缘区域(cell edge region,CER)频带.其中,CCR频段由CCU和毫微微小区用户(femtocell users,FUs)共享,而CER频段由D2D用户和CEU共享.在此网络部署下,能量约束D2D终端可以从CCU和CEU附近的射频(radio frequency,RF)干扰中及FU附近的RF信号中收集能量.基于稀疏泊松点过程模型,对CCU,CEU和FU上行链路的覆盖概率以及D2D传输做了全面研究.数值和仿真结果表明,所提方案能有效改善网络的能量和频谱效率.%To ensure the communication quality of cell edge users ( CEUs) and simultaneously improve the spectrum-energy efficiency, a novel energy harvesting scheme for D2D transmitter is proposed. Based on a cell split factor in three-tier heter-ogeneous networks ( HetNets) , the macrocell users ( MUs) are split into cell center users ( CCUs) and CEUs. At the same time, the total available spectral band is divided into cell center region ( CCR) band and cell edge region ( CER) band. The CCR-band is shared by CCUs and femtocell users ( FUs) and the CER-band is shared by D2D users and CEUs. Under the employment of this network, the energy limited D2D terminals harvest energy from not only the ambient radio frequency ( RF) interference from CCUs and CEUs, but also the ones of FUs. Based on these thinned Poisson point process models, we perform a comprehensive investigation on the coverage probabilities of CCU, CEU, and FU uplinks as well as the D2D transmission. The presented simulations and numerical results show that using the presented scheme can enhance the ener-gy-spectrum and improve the efficiency of networks.