Vertical-Joint-Detection for Doppler Frequency-Shift Estimation in Underwater Acoustic Communications

For the underwater acoustic communications, the signal faces the serious fading, causing the very low signal-to-noise ratio (SNR). Also, the low velocity of acoustic transmission and the high dynamic movement between the transmitter-receiver pair cause the high dynamic Doppler frequency-shift. To estimate the dynamic Doppler frequency-shift under not only the very low SNR but also the high dynamic movement scenarios, in this paper we propose one vertical-joint-detection (VJD) scheme to increase the detection probability. The VJD scheme includes two algorithms, called the single VJD and the iterative VJD, respectively. The single VJD algorithm uses multiple combination periods to narrow the search range and decrease the noise. The iterative VJD algorithm adopts the iterative of single VJD algorithm to further increase the detection probability. Theoretical analysis and simulation results show that our proposed scheme can significantly increase the detection probability of Doppler frequency-shift for underwater acoustic communications.