A Deep Reinforcement Learning based Scheduler for IoT Devices in Co-existence with 5G-NR

Co-existence of 5G New Radio (5G-NR) with IoT devices is considered as a promising technique to enhance the spectral usage and efficiency of future cellular networks. In this paper, a unified framework has been proposed for allocating in-band resource blocks (RBs), i.e., within a multi-cell network, to 5G-NR users in co-existence with NB-IoT and LTE-M devices. First, a benchmark (upper-bound) scheduler has been designed for joint sub-carrier (SC) and modulation and coding scheme (MCS) allocation that maximizes instantaneous throughput and fairness among users/devices, while considering synchronous RB allocation in the neighboring cells. A series of numerical simulations with realistic ICI in an urban scenario have been used to compute benchmark upper-bound solutions for characterizing performance in terms of throughput, fairness, and delay. Next, an edge learning based multi-agent deep reinforcement learning (DRL) framework has been developed for different DRL algorithms, specifically, a policy-based gradient network (PGN), a deep Q-learning based network (DQN), and an actor-critic based deep deterministic policy gradient network (DDPGN). The proposed DRL framework depends on interference allocation, where the actions are based on inter-cell-interference (ICI) instead of power, which can bypass the need for raw data sharing and/or inter-agent communication. The numerical results reveal that the interference allocation based DRL schedulers can significantly outperform their counterparts, where the actions are based on power allocation. Further, the performance of the proposed policy-based edge learning algorithms is close to the centralized ones.