Interference management and resource allocation for communications underlying downlink/uplink decoupling (DUDe) heterogeneous networks

Abstract

Resource allocation and Interference management are investigated for heterogeneous networks (HetNets) where tiers 1, 2 consist of macrocells, smallcells respectively. We first propose fractional frequency reuse scheme for uplink (UL) HetNets where macrocell subregions are preassigned to different SubBands (SBs) in order to mitigate the tier-1otier-1 interference. Nevertheless, cell-edge Macrocell User Equipments (MUEs) with high transmission powers still form dead-zones for nearby smallcell UEs. UE nearby edge of macrocells will connect to smallcell in the UL, which is also known as downlink(DL) Uplink(UL) decoupling (DUDe). Subject to quality of service (QoS) requirements and power constraints, we formulate a joint SubBand(SB) assignment and Resource Block (RB) allocation to maximize the data rate and minimize the co-tier/cross-tier interference. This proposed assign available SBs and RBs to smallcells. Considering the set of UE within a smallcell area as a virtual cell. As traditional DL/UL Coupled (DUCo) scheme generates significant interference proportional to cellular user density and user association bias factor, results obtained from the combination of proposed methods and developed algorithms reveal the potential of DUDe for co-tier/cross-tier interference mitigation which opens more room for spectrum reuse of DUEs with the help of carrier partitioning that is assigning different subbands to macrocell and smallcells.