Joint Spatial-Frequency Domain Message Passing Algorithm for Radio Resource Scheduling

Multi-user MIMO (MU-MIMO) enables a base station (BS) to transmit data streams to multiple users simultaneously on the same resource block (RB). In 5G specifications, a resource scheduling algorithm needs to consider both resource allocation in the spatial domain (i.e., MU-MIMO user scheduling on each RB) and frequency domain (i.e., RB allocation to each user). In addition, the scheduler must meet the real-time requirement. This paper presents a random sampling based joint spatial-frequency domain message passing (RS-JSFD-MP) algorithm, which is a novel radio resource scheduler that can meet the real-time requirement under the consideration of the finite buffer traffic scenario. The key idea of RS-JSFD-MP is to transform the scheduling problem into a graph model and design the corresponding low complexity message passing algorithm based on the random sampling approach. Experimental results show that RS-JSFD-MP can achieve better scheduling performance than existing greedy baseline algorithm, and can also obtain lower complexity by choosing an appropriate number of random samples. Moreover, RS-JSFD-MP facilitates parallel and distributed implementation, which helps to accelerate computation time to meet the real-time requirement on the resource scheduling algorithm.