Ray Tracing Based Channel Modeling and Characteristics Analysis in 6G IIoT scenarios

The industrial Internet of things (IIoT) is the key foundation for the shift from manufacturing to intelligent manufacturing in the "Industry 4.0" era. The 6th generation (6G) mobile communications will further facilitate the development of IIoT. However, IIoT wireless communications still face challenges due to the diversity of scenarios, channel specificity, and high requirements for latency and reliability. In this paper, a ray tracing (RT) based channel model for an indoor factory is developed and verified by channel measurements. Characteristics including path loss (PL), average delay power spectral density (DPSD), angular power spectral density (APSD), delay spread (DS), and coherence bandwidth are analyzed. The results show that ray tracing simulation results can match measurements well. path loss exponent (PLE) is less than 2 of free space at 5.5 GHz. The contribution of dense multipath components (DMCs) in average DPSD counts for 26%–60%. DS is positively related to the distance between transmitter and receiver (Tx-Rx) and the coherence bandwidth is much smaller than the system bandwidth, indicating severe frequency selective fading.