Fair and Efficient Listen Before Talk (LBT) Technique for LTE Licensed Assisted Access (LAA) Networks

摘要

Licensed Assisted Access (LAA) has been proposedby 3rd Generation Partnership Project (3GPP) in order touse Long Term Evolution (LTE) in the un-licensed band. Asthe centralized control of LAA has to co-exist with existingdistributed Wireless Fidelity (WiFi), efficient Listen Before Talk(LBT) technique is required to reduce interference and improvespectral efficiency. In this paper, we have proposed an LBTmechanism which attempts to share the medium in a fair mannerand improves the WiFi as well as combined (WiFi-LAA) systemperformances significantly. We have analyzed for enhanced Dis-tributed Coordination Function (DCF) model for LAA. We havealso observed network performance of the proposed LBT modelfor WiFi-LAA co-existence in the un-licensed spectrum usingNetwork Simulator (NS-3). The simulation based observationsare very much similar to that of the Matlab based analyticalresults. Also, observed results indicate that with proper choiceof LAA channel occupancy and back-off counter, WiFi as wellas overall system gain can be achieved.