Ultra-wideband channel modeling and characterization under low altitude scenarios

A Low-Altitude (LA) intelligent network with unmanned aerial vehicles is a key component of space-air-ground integrated communication networks. Moreover, the Ultra-Wideband (UWB) technique offers a promising solution of high-speed data transmission in the LA intelligent network due to its broad frequency spectrum. A deep understanding of UWB channels in LA scenarios is vital for design, optimization, and evaluation of reliable communication links. This paper proposes a novel LA UWB channel model, which comprehensively considers the impact of continuous frequency components within the band on the channel parameters and characteristics. On this basis, we present a detailed generation method of bandwidth-dependent channel parameters, i.e., Path Loss (PL), K-factor, cluster-related parameters, and Doppler frequency. Furthermore, the phenomenon of channel hardening and Doppler companding with respect to the ultra-wide bandwidth are analyzed. Finally, a UWB channel sounder is developed and applied to conduct low-altitude channel measurements in a 28 GHz campus scenario. The measured results such as PL, K-factor, and cluster numbers show good agreement with the proposed model, validating its accuracy and applicability.