Licensed and Unlicensed Bands Allocation for Cellular Users: A Matching-Based Approach

Long term evolution-unlicensed (LTE-U) technologies allow cellular users (CUs) to be served in unlicensed bands. However, how a CU properly chooses between licensed and unlicensed bands and how a CU can utilize the unlicensed bands without jeopardizing other unlicensed-band users, e.g., Wi-Fi users (WUs), remain as open problems. In this letter, we aim to optimize the allocation of radio resources in both licensed and unlicensed bands in an LTE-U and Wi-Fi coexisting scenario, where a CU can be allocated either a licensed or unlicensed band. We formulate a multi-objective optimization problem to maximize every CU's utility, while guaranteeing the throughput requirements of both CUs and WUs. We propose an algorithm based on one-to-one and many-to-one matching algorithms to solve it. The stability, Pareto optimality, and convergence of the proposed matching-based algorithm are proven. Simulation results show that the proposed algorithm can achieve near-optimal performance but with a low computational complexity.