Deterministic Ray Tracing: A Promising Approach to THz Channel Modeling in 6G Deployment Scenarios

Terahertz (THz) communication is considered to be a key enabling technology for 6G due to its abundant available spectrum resources. One pre-requisite for implementing THz communication systems is to understand and model the THz radio channel in 6G deployment scenarios. However, new radio characteristics in THz bands (e.g., channel sparsity, near-field propagation, and large-scale antenna configuration) have brought new opportunities and challenges to channel modeling in terms of modeling complexity and accuracy. In this work, we aim to address these opportunities and challenges with the deterministic ray tracing (RT) approach. First, the propagation characteristics in THz bands are discussed. We elaborate on why deterministic RT can be a promising approach to model the propagation characteristics in THz bands for 6G. Second, an RT-based channel modeling approach is presented, which uses channel measurement data to calibrate simulation parameters. Third, the performance of the RT-based channel modeling approach is demonstrated through a comparison between simulations and channel measurements. The comparison results show that the RT-based channel modeling approach can well describe the propagation characteristics (i.e., the delay and spatial dispersion, channel sparsity, near-field propagation, and non-stationarity) with reduced simulation complexity in THz bands.