Dynamic max TxOP algorithms in Licensed-Assisted Access system

摘要

Offloading the LTE data services to unlicensed spectrum has been considered by 3GPP in Release 13, which is defined as LAA (Licensed-Assisted Access). Unlicensed band is attractive because of its large amount of spectrum resource. However, coexisting with wireless devices already existing in unlicensed spectrum (such as Wi-Fi) is a primary issue be solved effectively. This paper proposed two dynamic max TxOP (transmission opportunity) algorithms based on Q-learning and expected capacity while inheriting the application of LBT(Listen-before-Talk), CCA-ED(channel clear assessment-energy detection) and discontinuous transmission. Using this framework, both LTE and Wi-Fi adjust the maximum occupancy time based on current traffic load or expected capacity dynamically, in order to improve the two systems' performance by configuring the transmission opportunity more reasonablely. Simulation results also show that the proposed approaches can enhance throughput and fairness significantly under both low and high traffic load, proving that the proposed dynamic TxOP algorithms offer new possibilities for better coexistence performance in LAA system.