The Key Technique Research Of TD-LTE System In Low-Altitude Air-ground Environment

In recent years, with the gradual opening up of China’s low-altitude areas, civil aircraft in low-altitude airspace restrictions will also be open, civilian aircraft at low altitude will be more and more popular. At the same time, in order to meet the request of the communication of aircraft at low altitude, low altitude ground communications research will be the hot point. Aiming at low altitude ground communications characteristics, following were studied in this paperSimulation results show that difference of measured blocking power and the blocking power of theoretical channel is small, which are independent of the frequency. To reduce congestion interference, transmission power should be appropriately reduced in communication when there is less elevation. The interference from TD-LTE systems for aircraft power control to blocking cell is not great. Therefore, in order to make space communications system interference and urban mobile communication system smaller, we should choose 1447-1467 MHz bandAnalysis of large-scale model of the radio channel, according to the empirical formula models have been proposed for the special case of the low-altitude space of theoretical analysis, by the measured data, we improve the existing empirical formula.For low-altitude space environment, the special nature of the communication between the aircraft, considering the introduction of D2 D communication mode analysis. To improve the quality of communication, we use coded cooperative relay-assisted D2 D system.The study includes a low-altitude areas of open space communication frequency, channel modeling, direct cooperative communications, which are of guiding significance to the design of the communication system of low-altitude.