Abstract:

In the processing of chirp signal in the frame synchronization, FRFT(Fractional Fourier Transform)transform or relevant matching mode usually leads to the problem of the large amount of calculation. It is difficult to achieve real-time processing in hardware platform like stm32. The paper studies on obtaining precise
synchronizing datum of signal frame in the condition of complex underwater acoustic communication channel. The simultaneous technique achieves coarse synchronization by detecting three single-frequency signals and realizes frame synchronization scheme of fine synchronization in dechirp compression processing method while dealing with Chirp signal. It adopts simulation test method to measure time synchronization disturbance of the frame synchronization scheme in different channels. Compared with fine synchronization scheme in the use of relevant matching mode and FRFT transform, dechirp processing method possesses less massive calculation deviation, although the performance is not that good. We utilize icroe2 platform and some other hardware to achieve frame synchronization scheme of dechirp compression, and verify the feasibility of the scheme by testing noise attenuation and water tank environment.

Key words: underwater acoustic communication, Chirp signal, relevant matching mode, fractional fourier transform(FRFT) transform, dechirp pulse compression processing method