Random waveform weak signal detection method and system under low signal to noise ratio

Abstract

The invention discloses a random waveform weak signal detection method and system under the low signal to noise ratio. The system comprises a low noise amplifier, a phase-locked loop, a microprocessor, a digital frequency synthesizer and an operation module, wherein the frequency of a weak signal to be detected is locked by simulating the work of the phase-locked loop, the microprocessor is utilized to measure the output frequency of the phase-locked loop, a direct digital synthesis circuit is controlled to produce a common-frequency signal according to a frequency value, and the common-frequency signal serve as a reference signal required by relevant detection. The operation module adopts a multiplier and an integrating circuit to achieve relevant detection, enables a mutual correlation value to be maximum by adjusting the phase of the reference signal in a stepped mode, obtains a regeneration signal identical to the detected signal in frenquency and phase and accordingly achieves weak signal detection and amplification. Under the low signal to noise ratio condition, the random waveform weak signal detection method and system has good linear measurement characteristic and high accuracy and can achieve automatic detection and regeneration amplification of the random waveform weak signal.

Description

technical field [0001] The invention relates to weak signal detection, in particular to a weak signal detection method and system of arbitrary waveforms under low signal-to-noise ratio. Background technique [0002] Weak signal detection in the background of strong noise is widely used in modern wireless communication, sensor and mechanical equipment detection and other fields. The commonly used detection methods include correlation detection and spectrum analysis. For weak signals, it is inappropriate to conduct spectrum analysis directly through waveform acquisition. At the same time, the reference signal used in traditional correlation operations is a square wave waveform, which is only suitable for weak signal detection with a fixed frequency. Harmonic components interfere with the detection of low-frequency weak signals; at the same time, due to reference frequency errors and reference signal phase shift errors, it is difficult to obtain accurate parameters of the detec...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a weak signal that can realize arbitrary waveforms in view of the defects in the prior art that it is difficult to obtain accurate parameters of the detected signal through the reference signal of the square wave waveform, and the reconstruction output of the detected signal cannot be performed. Weak signal detection method and system for automatic detection and regeneration amplification

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