A Method for Automatically Distinguishing FM Intervals of lfmcw Radar Based on Synchronous Pulse

Abstract

The invention discloses a method for automatically distinguishing frequency modulation intervals of an LFMCW radar based on synchronous pulses, belongs to signal processing technology, and specifically relates to signal synchronization technology. The present invention modifies the three-segment FM LFMCW radar transmission signal into four segments including: 1T positive slope segment, 1T negative slope segment, first T / 2 constant frequency segment, second T / 2 constant frequency segment, each segment A synchronous pulse signal is set at the initial moment of the signal, and a state counter is introduced into the processor, so as to realize the purpose of the invention. The effects include: there is no need to manually distinguish the synchronization, and only rely on the processor to judge the current sampling state to automatically distinguish the synchronization of the three-stage beat signal to realize automatic distinction; when there is an abnormality inside the system, such as the synchronization of the three-stage beat signal occurs In the event of dislocation, this method can also play the role of automatic error correction, and can quickly re-distinguish the three-stage beat signal synchronously; it is easy to implement, has high stability, and is suitable for real-time signal processing.

Description

Technical field: [0001] The invention belongs to signal processing technology, in particular to signal synchronization technology. Background technique: [0002] LFMCW (Linear Frequency Modulated Continuous Wave) radar is often used in target distance measurement because of its high measurement accuracy and the advantages of not introducing ambiguous distance. The transmitter generates continuous high-frequency equal-amplitude waves, and the transmission frequency changes linearly with time, generally according to the triangle law. The echo of the target is directly mixed with the transmitted waveform. Due to the time difference between the echo and the transmitted waveform and the reason of linear frequency modulation, the beat signal obtained after mixing will be a signal whose frequency is linearly related to the target distance, that is, The frequency of the beat signal is used to measure the distance of the target. [0003] For moving targets, because the frequency of...

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Problems solved by technology

However, in practical applications, the duration of each of the above three transmission signals is the same, and the three transmission signals are transmitted continuously, which makes it impossible for us to distinguish the echo signals corresponding to different transmission intervals.

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