Doppler resilience evaluation of different encoding techniques for underwater acoustic ranging systems

Underwater acoustic communication or localization systems can be affected by the Doppler effect when the receiver or emitter is in motion. In those cases, the use of an a appropiate encoding/modulating scheme play a pivotal role in the time of arrival estimations, avoiding the need of complex auxiliary Doppler compensation algorithms. This paper presents a Doppler resilience evaluation of Zadoff-Chu based schemes, modulated by phase modulation (QPSK), Orthogonal Frequency Division Multiplexing (OFDM) and Frequency Hopping Spread Spectrum (FHSS) modulation schemes. They are also compared to traditional binary Kasami codes modulated by BPSK. An underwater acoustic propagation model has been used to assessed the aforementioned schemes, to which the Doppler effect modeling has been also incorporated.