Doppler estimation technique using continuous wave signals in hyperbolic frequency modulated preamble based underwater acoustic communication

In this presentation, we propose a novel Doppler estimation technique that employs hyperbolic frequency modulated (HFM) signals in underwater acoustic communication. The Doppler effects resulting from rapidly changing channels significantly degrade communication performance, especially in fast-moving platforms such as autonomous underwater vehicles (AUVs). Therefore, the Doppler shift must be estimated and compensated. The previous method relied on sequences of down- and up-chirps, calculating the correlation function for each chirp, and estimating Doppler shifts based on time or frequency changes from the present correlation peak to the next correlation peak. In contrast, the proposed method uses continuous-wave (CW) signals instead of chirp signals to correlate with the received signal and analyze its variations. It does not require the knowledge of precise modeling of the transmitted HFM signals. Furthermore, it calculates Doppler shifts across the entire bandwidth, thereby allowing the use of a larger dataset. The performance of the proposed method will be compared with that of previous techniques by the sea trial. [This work is supported by Korea Research Institute for defense Technology planning and advancement (KRIT) grant funded by the Korea government (DAPA) (KRIT-CT-23-035-01, Multi AUV operation Technology for Mine Detection ('23–'28))]