A new approach of successive interference cancellation decoder in power domain non-orthogonal multiple access transmission

The NOMA (non-orthogonal multiple access) techniques developed in the context of 5G networks allows several users to share the same frequency band simultaneously. The main problem posed by this approach is the existence of interferences between the signals from different users. This article proposes a novel decoder model based on two successive interference cancellation operations in parallel. The first one cancels interferences successively in increasing direction of the powers while the second one cancels in decreasing direction. The simulation of network performances with the proposed decoding algorithm allows us to observe a clear improvement of the performances with regards to the standard approach of cancellation in descending order of powers. The simulation results indicate a significant improvement in network performances of more than 35% in terms of throughput, energy efficiency and spectral efficiency compared to the standard approach. Finally, we established by calculations and confirmed by simulations the existence of an optimum transmission power of the base station which allows maximization of the energy efficiency. Newton's method has been applied to find this optimal transmission power.