Minimizing outage probability driven wireless backhaul scheme in heterogeneous networks

Abstract

Heterogeneous networks (HetNets) attracts a lot of attention due to its high capacity and large coverage for future communication networks. However, with the large-scale deployment of small cells, HetNets bears dramatically increasing backhaul, which leads to a decrease of the outage performance. To improve the outage performance of HetNets, we propose a wireless backhaul scheme for a two-layer HetNets, which automatically switches the three basic modes of orthogonal multiple access (OMA), nonorthogonal multiple access (NOMA) and cooperative non-orthogonal multiple access (CNOMA). First, we analyze the backhaul capacity and outage performance of these three basic modes. Then, we design the power allocation schemes based on minimizing outage probability for NOMA and CNOMA. Using the designed power allocation schemes, we propose a wireless backhaul scheme that switches the three modes according to the channel quality among different base stations (BSs). Moreover, the closed-form of the corresponding outage probability is derived. Compared with the three basic modes, the proposed wireless backhaul scheme can achieve the best outage performance and a higher backhaul capacity. Finally, all the analytical results are validated by simulations.