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Novel Channel Access Mechanism for LTE and WiFi Coexistence

Facing the challenges brought by the surge in the demand for mobile data traffic and increasingly scarce spectrum resources, two well-known channel access mechanisms named as duty-cycle muting (DCM) and listen- before-talk (LBT) have been proposed. In this article, we propose a novel adaptive hybrid channel access scheme which takes advantages of both mechanisms. Based on the WiFi traffic and the available licensed spectrum resource, our proposal can adaptively adjust the important parameters, such as the back-off window size and the duty-cycle time fraction, while ensuring fair and harmonious network coexistence between the WiFi and LTE-U systems. It can realize the flexible handoff between the DCM and LBT mechanisms to meet the requirements of different markets as well. Moreover, joint transmission power and spectrum resource allocation is also studied to improve the spectral efficiency on both licensed and unlicensed bands. The effectiveness of the proposed scheme is finally validated by numerical simulations.