Performance analysis of LBT Cat4 based downlink LAA-WiFi coexistence in unlicensed spectrum
Wei Wang, Pingping Xu, Yuan Zhang, Hongyun Chu · 2017
Listen-Before-Talk category 4 (LBT Cat4) mechanism is considered as the most appropriate access method for Licensed-Assisted Access (LAA) framework, especially when LAA system coexists with WiFi system in unlicensed bands. Previous investigations of the LBT Cat4 based LAA-WiFi coexistence provide experimental results and simulation results, and theoretical analysis work is relatively rare. This work proposes an extended Markov model for downlink LAA LBT Cat4 access mechanism to theoretically analyze the system performance in the LAA-WiFi coexistence scenario. The proposed analysis model applies to the cases which have different network size and various LBT parameters. A series of ever-expanding network sizes are used to test the limit performance which verifies the universal applicability of this model. The simulation results show that the proposed analytical model is valid and accurate in predicting the downlink LAA-WiFi coexistence performance.