A General 6G Cross-Band Channel Model Toward Standardization Verified by 0.7–39-GHz Channel Measurements

The integration of sub-6 GHz, centimeter-wave, and millimeter-wave bands through cross-band coordination is recognized as a pivotal approach to optimize system performance in the sixth generation (6G) research. The existing standard channel models, e.g., 3GPP TR 38.901 and QuaDRiGa, support cross-band channel simulations. However, both models assume that multipath components observed at different bands are identical, which is inconsistent with channel measurements. In this paper, we propose a general cross-band channel model, which considers the birth and death of clusters across different bands. The evolution of clusters in temporal and spatial domains is also incorporated, where the common clusters observed at different bands are modeled to undergo identical birth-death processes. Furthermore, the frequency-dependent blockage losses caused by obstacles are embedded in the proposed model. A comprehensive analysis of channel statistical properties is conducted, including the delay/angular/Doppler spreads and stationary times/distances. Moreover, the similarities of cross-band channels in angular and delay domains are analyzed. To validate the accuracy of the proposed model, cross-band channel measurements across 0.7 to 39 GHz are conducted by time-domain channel sounders, which are capable of simultaneously measuring channels at two bands. Comparisons of simulation results from the proposed model, enhanced 6G pervasive channel model, and 3GPP TR 38.901 with measurement data reveal that the proposed model demonstrates the best alignment with measurements.