MODELING OF ADS-B DATA TRANSMISSION VIA SATELLITE

Abstract

For modelling of ADS-B messages transmissionvia low-orbit satellite constellation Іrіdіum the original model of a communication channel "Aircraft-to-Satellite-to-Ground Station" was built using MATLABSіmulіnk.The model comprises “Aircraft Uplink Transmitter” (Bernoulli Random Binary Generator, Convolutional Encoder, BPSK Baseband Modulator, High Power Amplifier with a memoryless nonlinearity, Transmitter Dish Antenna Gain), “Uplink Path” (Free Space Path Loss, Phase/Frequency Offset), “Satellite Transponder” (Receiver Dish Antenna Gain, Satellite Receiver System Temperature, Complex Baseband Amplifier, Phase Noise, Transmitter Dish Antenna Gain), “Downlink Path” (Free Space Path Loss, Phase/Frequency Offset), “Ground Station Downlink Receiver” (Receiver Dish Antenna Gain, Ground Receiver System Temperature, Viterbi Decoder), “Error Rate Calculation” block and “Display”.Modeling was realized without and with convolutional coding (r=3/4, K=7) at different noise temperatures and free space losses. Dependencies of a Bit Error Rate on free space path losses, antennas diameter, phase/frequency offsets, satellite transponder linear gain, aircraft and satellite transponder high power amplifier backoff level, and phase noise were received and analyzed.