A Group-Based Massive Multiple Access Scheme in Cellular M2M Networks

With the rapid development of machine-to-machine (M2M) applications, there is an explosion in the number of M2M devices emerging in the network. It poses a significant challenge for the network to support random access requests of a huge number of M2M devices. In this paper, we propose a novel group-based random access scheme for cellular M2M communications, where the beamforming technology enhanced by massive multiple-input multiple-output (MIMO) is applied. The key idea of the proposed scheme is that the evolved Node-B (eNB) makes use of multiple beams to divide M2M devices into different groups. Benefited from the spatial selectivity of beams, the interference among different groups is limited, which can efficiently reduce collisions during the random access procedure. Numerical results demonstrate that our proposed group-based random access scheme has the higher access success probability of devices compared with the legacy random access scheme.