LTE-U Spectrum Sharing Technology And Semi Physical Simulation Research

Wireless technology has greatly improved our life,with the rapid development of the mobile phone,the increase of users,high definition multimedia streaming service is emerging,the contradiction between the spectrum scarcity and the demand is becoming more and more prominent.Limited spectrum resources have been difficult to meet the needs of the frequency bandwidth.With the emergence of 4G and other emerging technologies,the allocated channel has been more and more crowded,and the licensed spectrum is not enough.For better use of spectrum resources,the spectrum of 5GHz unlicensed spectrum is becoming a hot research topic in communication industry.LTE system as the mainstream technology in 4G,the main advantage is that it can provide better connectivity,media access control,mobile management and excellent coverage,and these advantages combined with the huge 5GHz spectrum resource can be used to make LTE-U technology become a promising wireless access technology.The primary problem in the deployment of LTE systems in the 5 GHz unlicensed spectrum is the coexistence of other wireless access technologies(mainly WLAN)in the same frequency band.Researchs show that the LTE system and WLAN system coexist in the same frequency band will cause a serious interference to the WLAN system.Therefore,to realize the spectrum sharing in unlicensed spectrum,we need to solve the problem of coexistence between LTE and WLAN system,and ensure the WLAN system to be fair to access channel.This paper through the research of the coexistence of LTE and WLAN system in 5GHz unlicensed spectrum,two kinds of adaptive spectrum sharing mechanism is proposed,they are adaptive technology based on the LTE almost blank subframe and adaptive technology based on the LTE uplink power control theory.At the same time,through the research of the of game theory,power control game model based on cost function is proposed.Through the SystemVue software and other instruments,the semi physical simulation system of LTE system and WLAN system are established to verify this mechanism.The results show that the LTE/WLAN based on this two mechanisms can effectively improve the WLAN system performance when coexists with LTE,and achieve a fair coexistence.