Abstract:In this paper, a Near Space Ka frequency village system covering Channel Model is built. Firstly, Near Space Channel's geometry is discussed, according to different elevations, the communication coverage area is divided into high elevation area, middle elevation area and low elevation area. Secondly, the five factors those have an impact on channel characteristics, i.e. atmospheric absorption attenuation, troposphere flashing attenuation, cloud attenuation, raining attenuation and multipath effects caused by the ground body reflection, are analyzed. The summary is given that the influence of the raining attenuation and that of the multipath effects on Near Space Ka band communication channel are much larger than those of the other three factors. Finally, the impact of ground reflector and that of raining attenuation on the channel in different elevation cases are analyzed. And according to Ka band geostationary satellite communication channel signal's probability distribution of parameters in various weather conditions, Near Space Ka frequency village system covering Channel Model is simulated, and the BER performance simulation curves of different elevation areas are given. The model in this paper is of guiding significance in exploration and research of Near Space communication.