Sensing-Assisted Distributed User Scheduling and Beamforming in Muli-Cell mmWave Networks

Abstract

While distributed multi-cell resource allocation (D-MCRA) is promising for improving the spectral efficiency of cellular systems, it is challenging to realize in practice due to the large overhead for exchanging the channel state information (CSI) between base stations (BSs) and limited backhaul bandwidth. Inspired by the emerging integrated sensing and communication (ISAC) technique for mmWave systems, we propose in this paper a new distributed user scheduling and beamforming framework with a small signaling overhead. Specifically, we employ the ISAC signal for the BSs to track the kinematic parameters of the served users, which not only can be used to estimate the line-of-sight (LoS) CSI of served users but also can be exchanged with other BSs to construct cross-cell CSI. Based on this, we propose an enhanced proportional fairness zero-forcing greedy (PFZFG) scheduler for BSs to determine the set of users for ISAC signal transmission distributively. Afterward, each BS optimizes the ISAC beamformers based on a signal-to-average-leakage-plus-interference-plus-noise ratio (SALINR) criterion and subject to sensing error constraints. Simulation results show that our proposed design can approach the performance of the centralized algorithm.