A Novel Framework to Simultaneously Achieve Environment Sensing and User Positioning During Initial Random Access

Initial random access is a crucial process in wireless communication networks, which sets up reliable connections between multiple active users and the base station (BS). In this procedure, useful information, including beam pair, timing advance (TA), and channel state information (CSI), can be naturally obtained to achieve environment sensing and user positioning. Environment sensing is highly related to user positioning as it requires user-specific CSI, and more importantly, the multi-view observations from different user locations potentially benefit the fusion of the overall environment information. This makes joint environment sensing and user positioning of great significance. Moreover, initial random access provides observations from different users, avoiding the limited and insufficient observation of a single pair of transceivers, which helps to realize environment sensing in large scenarios. Therefore, in this paper, we propose a joint initial random access, environment sensing, and user positioning framework, exploiting direction, time-delay, reflection, and scattering information brought by beam pair, TA, and CSI. Furthermore, we illustrate the remarkable sensing and positioning performance of the proposed scheme in both light-of-sight (LoS) and non-light-of-sight (NLoS) scenarios.