Research On Communication Link Enhancement Schemes In ELAA Communication System

With the rapid growth of intelligent terminals and user demand for data services, the pressure of the spectrum in the wireless mobile communication network is even more severe. For supporting users'demand for data services and enhancement user experience, LTE eNB is deployed in unlicensed spectrum while ensuring coexistence between existing equipment, which is called eLAA technology.This paper firstly describes and analyzes the main difference between the eLAA technology and the traditional LTE system, further proposing downlink enhancement algorithms and uplink enhancement schemes for the downlink and uplink communication respectively. This paper proposes two Max TxOP algorithms which the traffic load and the current channel state is taken into account for the max channel occupancy time in downlink transmission. The downlink quality of service can be improved greatly by allocating time-domain resources efficiently. As for uplink enhancement, narrow band CCA and CCA window have been proposed to improve the efficiency of frequency reuse and solve the mutual interference between neighboring nodes problem. And then, the effectiveness and feasibility of different enhancement schemes on system performance are verified by system level simulation. Finally, the development of eLAA system is forecasted combining with the development trend of the current 5G key technologies.