Low-Complexity Wake-up Detector for underwater acoustic MODEM

Underwater acoustic MODEMs are usually powered by batteries, it is very important to design a low-power wake-up detector to save the power of modems. This paper proposes a low-complexity wake-up detector for underwater acoustic MODEM. A balanced Gold sequence is used to design a two-phase code signal as the wake-up signal. A detector algorithm is proposed that requires only one addition, one subtraction and two multiplication operations for each sample, thus achieving low computational complexity, at the same time, the algorithm can also provide accurate Doppler estimation and rough arrival time estimation for the wake-up signal. The proposed wake-up detection algorithm has been successfully tested in the lake experiment, the results show that, the proposed detector achieves high detection rate and low false alarm rate. Therefore it is suitable as a low-power wake-up detector for underwater acoustic MODEM.