Joint User Association and Resource Optimization for Unlicensed LTE Systems
Rui Liu, Qimei Chen, Guanding Yu · 2018
LTE-Unlicensed (LTE-U) has been widely considered as one of the most up-to-date promising innovations to achieve more ambitious data rate under a unified networking architecture by extending the LTE network into the bandwidth-rich unlicensed spectrum. In this paper, we study the user association optimization for LTE-U systems with multiple small cell base stations (SBSs) and WiFi access points (APs). Aiming at maximizing the whole throughput of LTE-U systems, a non-convex combinatorial optimization problem is modeled, which is NP-hard. By relaxing the integer variables to continuous variables, an upper-bound algorithm is developed based on the theory of sum-of- ratios optimization. Moreover, a heuristic algorithm based on the student project allocation (SPA) modeling is also developed, whose computational complexity is linear. Numerical results demonstrate the effectiveness and efficiency of our proposed algorithms.