Device to device (D2D) and nonorthogonal multiple access (NOMA) are promising technologies to meet the challenges of the next generations of mobile communications in terms of network density and diversity for Internet of Things (IoT) services. This article tackles the problem of maximizing the D2D sum throughput in an IoT system underlaying a cellular network, through optimal channel and power allocation (PA). NOMA is used to manage the interference between cellular users (CUs) and full-duplex (FD) IoT devices. To this aim, mutual successive interference cancellation (SIC) conditions are identified to allow simultaneously the removal of the D2D devices interference at the level of the base station and the removal of the CUs interference at the level of D2D devices. To optimally solve the joint channel and PA problem, a time-efficient solution of the PA problem in the FD context is elaborated. By means of graphical representation, the complex nonconvex PA problem is efficiently solved in constant time complexity. This enables the global optimal resolution by successively solving the separate PA and channel assignment problems. The performance of the proposed strategy is compared against the classical state-of-the-art FD and half-duplex (HD) scenarios, where SIC is not applied between CUs and IoT devices. The results show that important gains can be achieved by applying mutual SIC NOMA in the IoT-cellular context, in either HD or FD scenarios.

This paper studies the combination of full-duplex (FD) and half-duplex (HD) device-to-device (D2D) communications while underlaying a cellular system. Non-orthogonal multiple access (NOMA) is used to manage the interference between devices and cellular users using mutual successive interference cancellation (SIC) and to boost the performance of D2D underlay systems, which are mainly interference-limited. For this purpose, we derive the conditions allowing for the application of mutual SIC in FD-D2D and HD-D2D systems. We compare the performance of the proposed strategy against state-of-the-art, where SIC is not applied between D2D devices and cellular users. The results show that important gains can be achieved by using NOMA in this context and highlight the importance of SIC factors for determining the best transmission mode.

The densification of mobile networks should enable the fifth generation (5G) mobile networks to cope with the ever increasing demand for higher rate traffic, reduced latency, and improved reliability. The large scale deployment of small cells and distributed antenna systems in heterogeneous environments will require more elaborate interference mitigating techniques to increase spectral efficiency and to help unlock the expected performance leaps from the new network topologies. Coordinated multi-point (CoMP) is the most advanced framework for interference management enabling the cooperation between base stations to mitigate inter-cell interference and boost cell-edge user performance. In this paper, we study the combination of CoMP with mutual SIC, an interference cancellation technique based on power-domain non-orthogonal multiple access (NOMA) that enables multiplexed users to simultaneously cancel their corresponding interfering signals. A highly efficient inter-cell interference cancellation scheme is then devised, that can encompass several deployment configurations and coordination techniques. The obtained results prove the superiority of this approach compared to conventional NOMA-CoMP systems.