Optimization Research Spectrum Efficiency And Energy Efficiency In 5G Heterogeneous Small Cell Network

In recent years,the demand of mobile data has experienced the scale of explosive growth,and traditional cellular networks have become increasingly difficult to meet the high data rate requirements.As one of the technologies of the fifth generation communication,heterogeneous small cellular networks can significantly improve the network throughput,increase the network coverage performance,and enhance the use's quality of service and quality of experience.This paper studies the spectrum efficiency and energy efficiency optimization under heterogeneous small cellular networks.The details are as follows:1.The energy optimization problem of heterogeneous small cellular networks oriented to IoT is investigated.Heterogeneous small cellular networks provide wireless connectivity and coverage for mobile users and IoT nodes,however,the operation of a large number of base stations also brings power consumption.In order to reduce the energy consumption of the network,this paper proposes a unified framework of energy saving and energy harvesting in the three-layer heterogeneous model,composed of Macro-pico-femto to improve the energy efficiency of the network in the heterogeneous Internet of Things network.Specifically,cell zooming algorithm based on elastic mechanism is proposed to dynamically adjust the transmit power of small cells,and a heuristic greedy algorithm is proposed to solve the cell zooming problem of small cells;From the user side,the power-splitting model at the IoT cluster heads is adopted for energy harvesting to extend the life of the IoT network,and a SWIPT-CH selection algorithm is proposed to maximize the average residual energy of the network and reduce the resource competition between cluster heads and cluster members.The simulation results show that the scheme can reduce energy consumption by 17% compared with the traditional scheme and significantly improve the utility performance of the network.2.The spectrum efficiency optimization problem based on D2 D communication with energy harvesting is investigated.D2 D communication technology can significantly reduce the load burden and improve network throughput and spectrum efficiency.This paper combines D2 D communication with heterogeneous small cell network technologies to reduce network outage probability and increase network throughput,a spectrum splitting factor is proposed to divide macro cell users intomacrocell center users and macrocell edge users,edge users preferentially use D2 D communication to improve their Quality of Service.and a heuristic algorithm based on spectrum efficiency is proposed to optimize the spectrum resource allocation of the network.At the same time,the D2 D communication technology and energy harvesting are combined to reduce the network energy consumption.The simulation results show that the proposed algorithm has better utility performance than the heterogeneous network without D2 D communication,which also can improve the spectrum efficiency of the network with the probability of coverage guaranteed.