Analysis of Interference Avoidance with Load Balancing in Heterogeneous Cellular Networks

In heterogeneous cellular networks (HCNets) smallcells are overlaid with macro-cells to handle heavy cellular data traffic in an efficient way. To achieve fast and reliable access to data with a better coverage it is necessary to offload users to the underutilized small-cells from the congested macro-cells. Sharing of the same licensed frequency spectrum by small-cells and macro-cells results in heavy cross-tier interference which significantly affects the downlink SINR. In this paper, we investigate and analyze a joint frequency-division duplex based cross-tier complementary spectrum sharing technique which is also regarded as reverse frequency allocation (RFA) scheme with load balancing. This scheme mitigates inter-cell interference (ICI) and better balances the load across the network. It also guarantees enhanced spectral efficiency and coverage probability, particularly for cell edge users (CEUs). Numerical results indicate that load balancing together with RFA is necessary to enhance the coverage of CEU in co-channel HCNets.