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

Licensed Assisted Access (LAA) has been proposed by 3rd Generation Partnership Project (3GPP) in order to use Long Term Evolution (LTE) in the un-licensed band. As the centralized control of LAA has to co-exist with existing distributed Wireless Fidelity (WiFi), efficient Listen Before Talk (LBT) technique is required to reduce interference and improve spectral efficiency. In this paper, we have proposed an LBT mechanism which attempts to share the medium in a fair manner and improves the WiFi as well as combined (WiFi-LAA) system performances significantly. We have analyzed for enhanced Distributed Coordination Function (DCF) model for LAA. We have also observed network performance of the proposed LBT model for WiFi-LAA co-existence in the un-licensed spectrum using Network Simulator (NS-3). The simulation based observations are very much similar to that of the Matlab based analytical results. Also, observed results indicate that with proper choice of LAA channel occupancy and back-off counter, WiFi as well as overall system gain can be achieved.