Enhancing LAA Co-Existence Using MIMO under Imperfect Sensing

To meet the ever growing wireless network demands, in terms of subscribers and data throughput, operating long term evolution (LTE) in unlicensed bands, also known as license assisted access (LAA), is introduced as a promising solution. However, the LAA network must co-exist with incumbent IEEE $802.11$ systems. In this paper, we introduce MIMO operation to boost the LAA-Wi- Fi coexistence. We take the impact of imperfect sensing into account and analyze the key performance indicators (KPIs), such as throughput, and probabilities of successful transmissions and collisions. Moreover, the optimal LAA contention window size is characterized to maximize the LAA sum rate while assuring Wi-Fi throughput above a predetermined threshold. Numerical results show the efficiency of the introduced algorithm and that if the parameters are appropriately selected, the throughput of both systems increases.