A Novel GBSM and a RT Channel Model for 6G ISAC Systems

The research on channel modeling for integrated sensing and communication (ISAC) is an emerging field. In this paper, a novel geometry-based stochastic model (GBSM) is proposed for ISAC wireless channels. In ISAC scenarios, both communication and sensing systems share a common transmitter (Tx), and the corresponding channels are modeled as twin-cluster models. The channel model framework is outlined and the channel matrix is derived. Temporal auto-correlation function (TACF), doppler power spectrum density (PSD), and other statistical properties are analyzed. Theoretical and simulation results of both communication and sensing channel models are presented and differences between the two channels are explored. Moreover, a ray tracing (RT)-based deterministic channel model for ISAC scenarios is presented. Statistical properties including delay PSD, delay spread (DS) are analyzed. The comparative analysis between RT and GBSM simulations shows good agreement, confirming the accuracy of the proposed models.

I. Introduction

The sixth-generation (6G) mobile communication system is progressing steadily. ISAC is considered as a promising technology with the potential to revolutionize various industries. Foundational research on wireless channels not only supports the design, deployment, optimization, and standardization of communication systems but also plays a critical role in performance evaluation [1], [2]. In recent years, the research of ISAC is continuously advancing [3]. However, the advent of 6G ISAC is anticipated to introduce new channel characteristics, making existing communication channel models partly obsolete. Therefore, there is an urgent need to explore and create new channel models for 6G ISAC systems.