A 3D LEO Channel Model Based on GBSM for Satellite-Ground Communication Scenario

Abstract

Low earth orbit (LEO) satellites have the characteristics of low communication delay, low deployment cost, and wide coverage, which have become an important component of the 6G air-space-ground integrated information network. However, satellite-ground communication has a large propagation distance, complex fading, and fast terminal movement speed, causing the channel characteristics different from terrestrial communication networks. Therefore, channel modeling is necessary when deploying a satellite-ground communication network. In this paper, a 3D geometry-based stochastic model (GBSM) is proposed for satellite-ground communication links. The proposed channel model includes several environments such as urban, suburban, and rural. Based on this model, the channel impulse response (CIR) can be obtained, and the closed-form expression of spatial-temporal correlation function and Doppler power spectrum density are derived. Through simulation, the characteristics of large-scale fading and small-scale fading are analyzed, which depict the significant differences from the terrestrial networks. The relevant results can provide contributions to the design of future satellite-ground communication systems.