Adaptive freezing of backoff in LAA-LTE

The rapid increase in cellular data with the use of smart devices creates the demand for more licensed spectrum. Extending the carrier aggregation (CA) technique of long term evolution (LTE) to unlicensed band is considered as one of the promising solutions. The major concern is to attain the fair coexistence with the technologies that operate in these bands. In this paper, at first we have analyzed the effect of LTE on the performance of WiFi with listen before talk (LBT) coexistence mechanism. An LBT scheme with adaptable freezing time of backoff count based on negative acknowledgments (NACKs) is proposed which gives a substantial increase in throughput of both LTE and WiFi as compared to the LBT scheme. The proposed scheme is simulated for low, medium and high spatial density scenarios. It is seen to provide better throughput in the medium and the high dense networks while found to be not necessary for the low dense networks.