Shadow chasing : A resource allocation scheme for heterogeneous networks

In this paper, 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 Since the HeNB receives an outdated DCI due to backhaul delay, our Shadow Chasing algorithm (SCA) determines a likelihood metric for each PRB being either vacant or assigned to an outdoor MUE.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.