Optimal Power Control for Delay-Constraint Machine Type Communications Over Cellular Uplinks

To enable machine type communications (MTCs), MTC gateway (MTCG) is deployed in LTE-A cellular networks. An MTCG can collect data from a group of MTC devices (MTCDs) and forward the data to the base station (BS) via cellular uplinks. This letter proposes a nonorthogonal radio resource allocation (RRA) scheme for MTC-enabled cellular networks, in which an MTCG is configured as a full duplex (FD) relay to assist the uplink transmissions of a group of MTCDs. Through coordinating the transmit powers at the MTCG and MTCDs, the aim of the proposed scheme is to minimize the aggregate energy consumption of the MTCDs while satisfying their delay constraints. The simulation results show that most of the channel reuse gain of FD relaying can be achieved if the self-interference at the MTCG is controlled below a certain level.