Hierarchical resource allocation scheme for M2M communications enabled by cellular networks

Machine-to-machine (M2M) type communications (MTCs) over cellular networks feature the large number of MTC devices (MTCDs), small and time controlled data transmissions, and rigorous energy limitation. Considering full-duplex (FD) relaying can achieve high spectrum and energy efficiency, this paper proposes an MTC-enabled cellular communication scheme, where a traditional cellular user equipment (UE) is configured as an FD relaying based gateway to assist the uplink transmissions of the served MTCDs. The designed objective is to minimize the aggregate energy consumption of a group consisting of a UE and multiple MTCDs, while fulfilling their minimum throughput requirements. To this end, a convex optimization problem is formulated and a low complexity algorithm is also developed to find the optimal power allocation strategies for the UE and the MTCDs. The simulation results show that the proposed scheme can achieve most of the channel reuse gain of the FD relaying if the self-interference at the UE is controlled below a certain level.