Aircraft Formation Networking in High Altitude Based on Terahertz Communications

The large path loss limits the transmission distance of terahertz wireless communication in the atmosphere. To realize long-range transmission of terahertz waves between the ground and the satellite, the first and key step is to find low attenuation atmospheric transparent windows. In this paper, based on the characteristics of atmospheric distribution in China, atmospheric model (am) is used to compute and compare atmospheric absorption attenuation of terahertz waves in two representative cities, and obtain the most ideal ground-based site suitable for terahertz communication between the ground and the satellite in China. Subsequently, by means of real atmospheric data and layered transmission theory, the total path loss of terahertz communication between the ground and the satellite is calculated. Combined with the signal transmit power, antenna gain, Signal-to-Noise Ratio (SNR), noise power and the corresponding path loss threshold, the total usable bandwidth and atmospheric windows in the 10−15 THz frequency band are given. Moreover, by taking the High Altitude Platform as the terahertz communication relay link between the ground and the satellite, the usable atmospheric windows in the 1−15 THz frequency band with antenna gain of 0−100 dBi are given, which provide theoretical and numerical reference for the establishment of ground-satellite communication links and the selection of ground-based sites and communication frequency bands in China.

For the special meteorological condition of high altitude transmission，first，the influence of atmospheric turbulence on the Terahertz wireless communication is analyzed, and the atmospheric constants model with increase in height is given. On this basis, the relationship between the flicker index and the high altitude horizon transmission distance of the Terahertz wave is analyzed by simulation. Then, through the analysis of high altitude path loss and noise, the high altitude wireless link model is built. Finally, the link loss budget is given according to the current Terahertz device parameters, and bit error rate (BER) performance of on-off keyed modulation (OOK) and pulse position modulation (PPM) in four Terahertz frequency bands is compared and analyzed. All these above provided theoretical reference for high-altitude Terahertz wireless communication transmission.

NOMA based Terahertz Communication for High Altitude Platform System