Method for performing frequency identification on underwater sound keying frequency shifting signal

Abstract

The invention discloses a method for performing frequency identification on a underwater sound keying frequency shifting signal. The invention adopts a method of combining a band-pass filter of a dual-channel extreme-narrow band with an amplitude limiting comparator to separate a underwater sound remote signal from environment interfering noise so as to reduce the influence of multipath effect; the method comprises the step of directly computing the period and frequency of the signal through the acquisition of time width of a pulse signal or the number of a rising edge or a falling edge of the pulse signal; the discrete Fourier transformation (DFT) operation is evaded, the convolution operation in a conventional signal frequency identification method is avoided, a large-scale floating point operation is evaded, the running is realized on a hardware circuit platform of a low power consumption single chip, thereby controlling the scale and power consumption of a signal processing system; and the instantaneity of the processing result is improved.

Description

technical field [0001] The invention relates to the technical field of frequency identification, in particular to a method for frequency identification of underwater acoustic keying frequency shift signals. Background technique [0002] Underwater acoustic remote control and underwater acoustic communication are a method of transmitting information using underwater acoustic channels, and underwater acoustic channels are random fading channels that are uneven, time-varying, and space-varying, with multi-path effects and reverberation effects The effect of the ocean environment will cause distortion and fluctuations in the sending and receiving signals of the underwater acoustic transducer. At the same time, the noise of the ocean environment is also a kind of interference to the underwater acoustic signal. From the perspective of communication theory, the frequency shift keying (FSK for short) technology with small frequency shift is beneficial to resist channel fluctuation a...

AI Technical Summary

Problems solved by technology

However, the discrete Fourier transform must use the convolution operation. When implementing the algorithm on the embedded system platform, a large number of floating-point operations are involved, which takes up more hardware resources and affects the real-time performance of signal processing.

At the same time, the above method has higher requirements on the hardware circuit platform, and the system scale and power consumption requirements are also increased accordingly.

Images