Underwater acoustic remote control based on time-frequency joint coding

In order to ensure the navigation security of unmanned underwater vehicles (UUVs), an underwater acoustic remote control system is essential. An applied remote control method is proposed. The information to be transmitted is modulated both on frequency and pulse intervals. Reliability is guaranteed, and the communication rate is improved at the same time. To reduce the correlation between reverberation and response, opposite chirp rates are used for up-run and down-run instructions. The incoming signal strength, reference signal parameters and the relationship between the incoming signal and the reference signal are utilized to evaluate the hypothesis testing adaptive threshold. A constant false alarm rate (CFAR) detector is realized. Through estimating the channel impulse response, a deconvolution Doppler frequency correction method is proposed. After dividing the band of frame head, a sub-band pre-detector and a copy sequence notch filter are designed to suppress interference from other acoustic platforms. The feasibility and effectiveness of these methods are verified by lake trial results.