Joint pairing and resource allocation for backhaul of small cells using NOMA

•The main objective of this paper is to design and model a joint pairing and resource (bandwidth and power) allocation scheme for the backhaul of small cells. Bounds on the power coefficient of the near and far user are computed. The significant contributions of the proposed model are as follows:•We formulate the joint problem of resource allocation and pairing of backhaul of small cells. The resources considered are bandwidth and power coefficient for the near and far user. The problem takes into consideration the load of each small cell.•We propose a heuristic to solve the formulated problem as the problem is NP-hard. The main theme of the heuristic is based of the bound of power coefficients and exhaustive search for the small cell pairing.•We compare the performance of the proposed heuristic with a discretized exhaustive search strategy. Small cells is a promising technique to improve the spectral efficiency or quality-of-service (QoS) of a cellular network as it reduces the distance between the user and the base station (MBS). It has been proposed for indoor as well as outdoor users. For the outdoor scenario, the backhaul (the link from a small cell to the core network) of the small cell has always been a challenging issue. Different schemes have been proposed in the literature such as optical fiber, satellite and wirelessly through MBS. Wireless backhaul through MBS has gained a lot of attention in the literature and different resource allocation with orthogonal resources strategies have been proposed for it as well. Apart from orthogonal techniques, non-orthogonal multiple access (NOMA) is a multi access technique with the basic principle of sharing the same bandwidth resource between multiple users with varying power levels. Successive interference cancellation (SIC) is implemented on the receiver side to decode the data. This overall increases the spectrally efficiency of the network and make NOMA a promising candidate to be deployed on the backhaul of the small cell network. In this paper, we investigate the problem of pairing of small cells and the allocation of resources. Small cells' load information plays vital role to solve this problem. An optimization problem with an objective of maximizing the spectral efficiency (SE) of the backhaul network is formulated. The joint problem is decomposed and solved using a load-based heuristic for the backhaul of small cells. Furthermore, our performance evaluation shows that the proposed heuristic is abl