Morse signal detection method based on Kalman filtering algorithm

Abstract

The invention discloses a Morse signal detection method based on a Kalman filtering algorithm. Signals are subjected to bit synchronization by means of a self-synchronization algorithm, an adaptive energy threshold is set for interference noise energy time varying by means of the Kalman filtering algorithm to conduct soft judgment on calculated actual energy values of the signals, and then the purified CW signals are recognized. According to the method, the CW signals can be effectively detected out synchronously under a strong noise background, the anti-interference capacity is high, the error rate is low, the adaptivity is high, and the real-time performance is better.

Description

technical field [0001] The invention relates to the technical field of communication signal processing, in particular to a Morse signal detection method based on a Kalman filter algorithm. Background technique [0002] High-frequency CW (Morse) signal communication is a radio communication method in the 3-30MHz frequency band. The required equipment is simple, the occupied frequency band is narrow, and the transmission efficiency is high. It is a signal with high resolution and strong anti-interference ability. Strong, a communication method with the same power and the longest communication distance, and its transmitter device is simple and can work in a low signal-to-noise ratio environment. It is an important means of tactical communication at present. It has a wide range of applications in civilian areas with high anti-interference requirements. High-frequency CW signal communication technology is usually divided into two steps: signal automatic detection technology and ...

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Problems solved by technology

[0003] For a long time, CW communication has been completed by manual operation, but there are serious fading phenomena and multipath effects in short-wave high-frequency ionospheric channels. At the same time, considering that the electromagnetic environment for wartime communication is very harsh, in the case of strong noise interference and high code rate Under the circumstances, it is difficult for the human ear to distinguish the information represented by the CW signal, and with the development of modern communication technology, the communication process is gradually accelerated, and the artificial CW communication speed is relatively slow, and the bit error rate is relatively high, resulting in a decline in communication performance.

[0004] At present, there are many studies on the automatic detection and decoding of CW signals, but there is no method that can detect and extract pure high-frequency CW signals synchronously in the background of strong noise.

"Morse Code Automatic Decoding System" (published in "Military Industry Automation" in June 2007) uses the envelope detection algorithm to extract the CW signal. For this method, when the code rate is high or under strong noise interference, the It will be difficult to track the changes of the signal waveform in real time, so the bit error rate is high and the performance is seriously degraded

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