Low Repetition Frequency Modulation Method of Optoacoustic Pulses for Underwater Communication

Compared with the traditional underwater acoustic communication method, optoacoustic communication technology uses acoustic pulses generated by high-intensity laser irradiation on the water surface to realize underwater communication, which has the advantages of flexibility, high concealment, etc. The optoacoustic signals generated under the linear mechanism have good repeatability, which is beneficial for underwater communication. Based on the above character-istics, this paper proposes a low repetition frequency modulation (LRFM) method and designs a frequency domain demodulation method that calculates the sum of harmonic energy for comparison and judgment. Finally, we optimize the parameters of the modulation signal length and repetition frequency to further improve the demodulation performance and prove the feasibility of the modulation method in this paper through the anechoic pool experiment.