Efficient listen before technique for LTE-WiFi co-existence in unlicensed bands

Abstract

In a moderate to high traffic scenario wireless fidelity (WiFi) performance degrades severely due to interference and back-off mechanism. Licensed assisted access (LAA) has been proposed by 3rd Generation Partnership Project (3GPP) to use long term evolution (LTE) in the un-licensed spectrum. As the centralised 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 of WiFi and LAA users. In this paper, we have proposed an LBT mechanism to share the medium in a fair manner and improves both WiFi-LAA combined system performances significantly. We have also analysed closed form solution for the LBT technique. We validated network performance of proposed LBT model using network simulator (NS-3) and Matlab. The results indicated that with proper choice of LAA channel occupancy and backoff counter, significant performance gains of WiFi-LAA can be achieved.