Enhanced Listen-Before-Talk Mechanism For Licensed Assisted Access In Unlicensed Spectrum

In order to meet the requirement of dramatically growing mobile data, the operators improve their network by aggregating multiple carriers to increase the system capacity. Due to the limited availability of licensed spectrum, unlicensed spectrum with large amount of resources has attracted more and more world-wide interests recently. The Licensed Assisted Access (LAA) using LTE(-A) on unlicensed bands is investigated and being standardized in 3rd Generation Partner Project (3GPP) Release-13. This paper focuses on studying the co-existence techniques of multiple operators within LAA system. Although Listen-Before-Talk (LBT) mechanism is identified as a necessary feature in LAA to cope with the interference between Wi-Fi and LTE, it may not be efficient enough to mitigate the interference within LAA while between different operators. In this paper, we propose an enhanced LBT mechanism with cross-correlated information by utilizing assistant measurement report from users. System level simulation is conducted to illustrate the performance gain of the proposed method. It is shown that the enhanced LBT mechanism has outstanding performance in medium and high traffic scenarios in terms of user experienced throughput.