Performance Evaluation for Coexistence of LTE and WiFi

As the traffic load in cellular networks grows exponentially, the capacity crunch is becoming more and more severe, partially due to the fact that the licensed spectrum is rather limited and dwarfed by the ever-increasing traffic demand. To alleviate this issue, the unlicensed spectrum has attracted significant attention as a piece of valuable resource for offloading and for best effort traffic. Therefore, operating cellular technologies with high spectral efficiency, mainly the Long Term Evolution (LTE), in the unlicensed band, is deemed promising. However, the coexistence of different wireless technologies such as LTE and WiFi deployed in the same frequency band is a challenging problem. In this paper, we study the coexistence between LTE and WiFi. Three schemes for coexistence are proposed, evaluated, and compared, based on which the impacts of the coexistence on WiFi performance and LTE performance are analyzed. This study can be useful for the standardization and deployment of LTE on the unlicensed band.