Single channel optimum constant-mould interference rejection method and system in civil aviation air-ground communication

Abstract

A single-channel optimum method and system for constraining constant modulus interference in the process of civil aviation ground-air communication comprises that very high frequency amplitude-modulated signal received by the antenna is converted into intermediate frequency signal; the converted intermediate frequency signal is implemented with the process of digital conversion and filtration extraction; the carrier frequency of the signal after the process of filtration extraction is estimated; and then the process of adaptive notch filtering is implemented; the signal, the amplitude modulation and carrier wave of which are removed, is implemented with the process of orthogonal transform; the signal after the process of orthogonal transform utilizes non-linear least squares to estimate the constant modulus interference signal; the signal after the process of orthogonal transform and the estimated constant modulus interference signals are delivered into a subtracter together and then the two signals are subtracted; the resistive component of the subtracted signal is taken to be multiplied with the carrier wave signal for modulation; and then the high-frequency clutter is removed through a low-pass filter and the audio frequency signal is output. The single-channel optimum method for constraining the constant modulus interference can estimate the modulation and the phase of theconstant modulus interference in real time and avoid the convergence problem of the ordinary adaptive interference constrain method; two methods of batch processing and recursion are presented and the convergence property of the recursion method is proven.

Description

technical field [0001] The invention relates to a single-channel self-adaptive interference suppression method for civil aviation ground-air communication. In particular, it relates to a single-channel optimal constant-mode interference suppression method and system in civil aviation ground-air communication that conforms to the existing civil aviation ground-air communication system, is simple to implement and has excellent performance, can improve communication quality, and enhance flight safety factor. Background technique [0002] According to Volume I of Annex 10 of the International Civil Aviation Organization Convention, in air traffic control, the contact between ground controllers and air pilots mainly relies on VHF (very high frequency) ground-to-air communication stations, which use AM (amplitude modulation) work Way. The advantage of amplitude modulation is that it occupies a narrow frequency band, saves frequency resources, and is easy to implement with hardwar...

AI Technical Summary

Problems solved by technology

However, there are problems that the adaptive canceller converges slowly, and the initial value and step factor are difficult to select

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