Abstarct: The increase in wireless network users, resulting in increased network traffic and the demand for high-quality service, have made the fourth generation unable to meet these needs. So we have to look for ways to meet these needs. One of the technique that has recently been very much considered and presented as a candidate for the fifth-generation systems is non-orthogonal multiple access, in which, unlike multiple orthogonal access techniques, more than one user can use resources in which results in increased spectral efficiency and network energy efficiency. In this paper, we aim at evaluating the energy efficiency of a multicellular system baxsed on a non-orthogonal multiple access technique. First, we consider a simple model system and then consider the energy efficiency problem and develop it for single-cell and multi-cellular states. Allocation of resources in these systems is a non-convex problem that can’t not be easily solved with existing tools, so using the approximation methods we turn non-integral optimization into a convex and solvable problem. Finally, by performing simulations, a comparison is made between orthogonal access and non-orthogonal access. Concerning the simulations, we conclude the use of non-orthogonal access methods results in the efficiency of cellular networks relative to the orthogonal access method at the cost of increasing the complexity of the sender and the receiver increases.