In this paper, we present a method for resource allocation for small cells that integrate licensed and unlicensed RF operations motivated by the widespread WiFi hotspots and the common inclusion of WiFi interface in most cellular terminals. Small cells have proven popular for cell coverage enhancement and traffic offloading from macrocells. We formulate an optimization problem that jointly allocates resources over both licensed and unlicensed bands with the goal of maximizing sum small cell user equipment (SUE) rate while achieving fairness among these user equipments and controlling inter-cell interference to neighboring macrocell users. The proposed solution further considers the Quality of Service (QoS) requirement of SUE traffics to be distributed over both licensed and unlicensed bands. We show the formulation of the proposed optimization problem as an efficient and low complexity linear programming. We further show that our problem formulation can be modified to maximize the revenue of mobile network operators. Our proposed solution achieves better performance than several existing solutions.

No abstract

No abstract

No abstract

In this paper 1 , we propose a resource allocation scheme for interference mitigation in heterogeneous networks to simultaneously serve both Macrocell User Equipments (MUEs) and Home User Equipments (HUEs). In the proposed Shadow Chasing scheme, a Home eNB (HeNB) uses Downlink Control Information (DCI) together with ACK/NAK feedback to assign its HUEs the Physical Resource Blocks (PRBs) that are also potentially used by outdoor MUEs. Since the HeNB receives an outdated DCI due to backhaul delay, our Shadow Chasing algorithm (SCA) determines a likelihood metric for each PRB being either vacant or assigned to an outdoor MUE. By dynamically separating MUE and HUE PRB assignments, SCA can control the downlink interference to MUE. Our numerical examples demonstrate effective reduction of probability for PRB assignment collision and MUE interference over random assignment and a DCI based assignment that does not take into account the delay effect nor the ACK/NAK signal.