3. Air traffic increases steadily over the years that lead to the increase of flights through the Poles, oceans and regions with reduced radar coverage and current ATM network can’t handle with it. Thus, there is a need that standards of safety and efficiency should be maintained or even enhanced. Air traffic increases steadily over the years that lead to the increase of flights through the Poles, oceans and regions with reduced radar coverage and current ATM network can’t handle with it. Thus, there is a need that standards of safety and efficiency should be maintained or even enhanced. Therefore, there arises a necessity of conversion from the expensive ground-based systems to the cheap satellite- based systems that provide global coverage. Therefore, there arises a necessity of conversion from the expensive ground-based systems to the cheap satellite- based systems that provide global coverage. As a solution, there are used the latest Iridium satellite constellation and developed program of Automatic Dependent Surveillance Broadcast (ADS-B). As a solution, there are used the latest Iridium satellite constellation and developed program of Automatic Dependent Surveillance Broadcast (ADS-B).

7. ADS-B technologies with Iridium LEO constellation provide global, real-time aircraft position information, weather information, full coverage over oceanic airspace, polar routes, remote and mountainous regions, where ground station network is impossible and impractical to employ.

9. Ground Station Downlink Receiver FEC, Demodulator, OFDM receiver Aircraft Uplink Transmitter FEC, BPSK,QPSK,16QAM, 64QAM, OFDM transmitter Error Rate Calculation, SNR estimation Bernoulli Binary Generator Uplink Path Satellite Transponder Downlink Path

13. Dependencies of a SNR on free path losses for different modulation modes, transponder noise temperatures and channel bandwidths Aeronautical satellite channel simulation N OFDM =1; amplifier nonlinearity - disabled; transponder linear gain -1 dB

14. Dependencies of a SNR on free path losses for different modulation modes, transponder noise temperatures, number of OFDM symbols Amplifier nonlinearity - disabled; amplifier linear gain - 1 dB

15. Dependencies of a SNR on free path losses for different modulation modes and types of amplifier nonlinearity T noise = 20 K, N OFDM =1; B = 3.5 MHz

16. Dependencies of a SNR on free path losses for different modulation modes and cyclic prefix values T noise = 290 K, N OFDM =1; B = 3.5 MHz

17. The most efficient, accurate high data transmission can be provided by an optimal combination of model parameters: modulation schemes, coding, noise temperature, channel bandwidth, number of OFDM and cyclic prefix. Obtained results: 1.The 64QAM provides highest data transfer rate but sensitive to noises. BPSK and QPSK are more robust to the interferences; 2.The reduction of transponder noise temperature, channel bandwidth and cyclic prefix leads to more efficient data transfer; 3.The greater the number of OFDM the higher the value of SNR; 4.The higher the average input power, more accurate signal is received.