Performance of Multi-Carrier LBT Mechanism for LAA

In Rel-13, Licensed-Assisted Access (LAA) to Unlicensed Spectrum has been approved as a new work item to meet the increasing traffic demands for operators. For LAA, the listen-before-talk (LBT) is efficient way to ensure fair and friendly coexistence in unlicensed band with other operators and radio access technologies (RATs). To use more bandwidth, multiple unlicensed carriers could be configured and activated independently for LAA. However, the general LBT mechanism is unfeasible for multi-carrier operation due to RF leakage, which would result in low probabilities for simultaneous data transmission over multiple carriers. In this paper, we first analyze the coexistence mechanism for Wi-Fi and LAA, and then proposed an effective LBT mechanism for LAA multi-carrier operation so as to provide better coexistence fairness with other nodes (e.g. Wi-Fi) and to increase bandwidth available. Furthermore, the simulation results show that the proposed solution could provide better fairness and performance in comparison with other solutions when LAA coexists with Wi-Fi.