Исследование эффективности помехозащищенности радиоканала авиационной радиосвязи

Abstract

When performing aviation flights the high-quality and reliable communication with the control room becomes important for ensuring the crew safety. The purpose of the study is to investigate the quality of aviation radio communication in different methods of information transmission for developing the technical solutions of radio communication perfection. The equipment used today is designed for instant selection of preset channels and data exchange at fixed operating frequencies of ground control points with aircraft radio equipment in the meter and decimeter ranges. The most important requirement for the aviation radio communication systems is to ensure a high level 
 of noise immunity including protection against active interference. There is considered the process of frequency changing, or frequency hops, as the most successful at the first stage of the study in order to find the least interference-prone operating frequency. The use of pseudorandom frequency changing of radio communication between the ground control points and aircraft radio equipment is studied as one of the ways of leveling interference effects. To increase the stability of the radio line, it is necessary to use digital methods of information transmission. The use of digital methods of encoding information leads to low-level errors in the processes of discretization, modulation, amplification, demodulation and filtering. Due to this, nonlinear quantization allows for a higher level of signal-to-noise ratio. With a constant power level of the transmitter it is possible to carry out stable communication even at higher values 
 of the signal-to-interference ratio, which generally leads to the increasing radio transmission range. Using highly robust coding methods, the probability of error can also be reduced. There are studied different parameters reflecting the quality of information transmission over the radio channel: speech intelligibility, probability of erroneous reception of symbols. Thus, the digital methods of information transmission have higher noise immunity compared to the analog ones, even without special protection measures. Using special measures (noise-proof coding, pseudorandom frequency changing) can significantly increase the jamming protection of the radio communication system.