A Novel Sonar-Communication System Based on Incremental-Frequency-Interval Acoustic Frequency Comb Signal

Joint communication and detection systems present distinct benefits in terms of spectral efficiency and cost-effectiveness for the Internet of Underwater Things (IoUT). Due to the unique characteristics of underwater acoustic channels, existing radar communication (RadCom) signals and detection methods have shortcomings when applied underwater: 1) Doppler ambiguity caused by signal features. We propose a novel incremental frequency interval acoustic frequency comb (IFI-AFC) signal which performs better autocorrelation performance in the Doppler dimension to overcome the Doppler ambiguity underwater. 2) Range and velocity constrain each other caused by the popular Range-Doppler process method. We propose the energy spectrum matching (ESM) algorithm which serves as an alternative to the Range-Doppler process in the underwater scenario, avoiding the constraint relationship between maximum measurable unambiguous range and velocity. The proposed sonar-communication (SonarCom) system based on IFI-AFC and ESM has excellent multitarget discrimination capability, making it more suitable for applications in SonarCom scenarios.