Satellite Channels Based on IEEE 802.16 Standard

This chapter considers the modeling of RPAS/Aircraft data transmission via channels based on IEEE 802.16 standard. RPAS communication channel with a fading was analyzed using original model. Dependencies of a SNR in ground receiver on a SNR in downlink for different types of RPAS amplifier nonlinearity were obtained. Signals constellations of received signals were compared for different Doppler shifts. The influence of the aircraft transmitter nonlinearity for different types of fading in the channel was studied using “80216dstbc Rayleigh,” “80216dstbc Rician,” “80216d Rayleigh,” and “80216d Rician” models. The possibility of the nonlinearity correction using pre-distortion was revealed. The impact of space-time diversity (MISO 2x1) for different types of fading in the channels was investigated. The effect of the Doppler's frequency shift on the operation of communication channels was analyzed.

Parameters Estimation of Aircraft and RPAS Satellite Channels Based on IEEE 802.11a Standard

This chapter deals with parameters estimation of satellite channels based on IEEE 802.11a standard. Dependencies of a signal to noise ratio on free space path loss for different types of modulation (BPSK, QPSK, 16QAM, 64QAM), noise temperatures, number of OFDM symbols, Doppler frequency offsets, satellite amplifier gain, and aircraft antenna diameter were received using model “OFDM_FSPL_Sat_FSPL_802.11a.” A method for parameters estimation of satellite OFDM communication channel was proposed. The spectrums and signals constellations of received signals were compared for different types of the amplifier nonlinearity. The developed model allows predicting spectral regrowth of digitally modulated OFDM signals due to the amplifier nonlinearity. Channel parameters were received for the Rayleigh and Rician fading, different types of Doppler spectrum, the gain of multipath channels, the delay time of message flow using models “OFDM_Multipath_Sat_Multipath_802.11a,” “OFDM_AWGN_Sat_Multipath_802.11a,” and “OFDM_FSPL_Sat_Rician_802.11a.”

Modeling of Aircraft and RPAS Data Transmission via Satellites

This chapter is devoted to the modeling of aircraft data transmission via low-orbit satellites. Satellite communication channel models were designed, which allow to investigate BER dependencies on the type of signal modulation, information transfer rate, signal power, antenna diameters, and nonlinearity of a high power amplifier. Impact of a modulation type (BPSK, QPSK, 8PSK, 16QAM), Eb / N0, satellite transponder amplifier gain without and with coding on a BER was investigated. Effectiveness of error detection and correction was analyzed using classic linear block and convolutional codes. Free space path loss, AWGN, and radio frequency satellite channels were considered. MIMO 2 × 1 and 3 × 2 fading uplink/downlink channels with antenna diversity were analyzed. Results were compared with AWGN uplink/downlink channels. On the base of these models, channels integrity was investigated.

Antenna for ADS-B Signals

This chapter deals with calculations of the microstrip antenna and the linear phased array that were based on the method of moments using Antenna Magus software. The analysis of the characteristics of these antennas at different emitter numbers and different types of the amplitude distribution was carried out. Calculations of electric field intensity and directional patterns for collinear antennas were provided. The method of moments in the framework of two program complexes was used. Comparison has shown high level of results coincidence. The sample of the antenna is described, which is used in operating system for reception of ADS-B signals from airborne transponders.

Investigation of Aircraft and RPAS Data Traffic via Satellite Communication Channel

This chapter considers simulation of traffic in the transmission of ADS-B messages with the help of low-orbit satellite complex Іrіdіum. Different models of communication channel “Aircraft-Satellites-Ground Stations” were built using NetCracker Professional 4.1 software. Influence of aircraft and satellites amount on average link utilization and message travel time was studied for telecommunication channels with intersatellite link and bent-pipe architecture. The effect of communication channel “saturation” during simultaneous data transmission through a satellite communication channel from many aircraft was investigated. Influence of protocol type, size of transactions, time between transactions, and channel latency on traffic was studied. A method for estimation of traffic losses was proposed and dependencies of the data loss coefficient on the size of transactions were received.

Air Traffic Monitoring Using ADS-B System

This chapter describes the system created for ADS-B messages receiving. For this an antenna, ADS-B signals receiver, a decoder was made and software was installed. This system was allocated at the Department of Air Navigation Systems in the National Aviation University and was used for students training and investigations. Original software for modeling of real-time TCAS operation was developed using MATLAB. The experimental model with data exchange between onboard systems via Wi-Fi network was created. This model was used for modeling of aircraft approaching. Such model can be used as a base for creation a collision avoidance system of RPAS.