Conformação de feixe otimizada para transmissão de sinais subaquáticos

Abstract

This work presents an optimized underwater transmit beamforming scheme using a linear array of projectors. In the array of projectors investigated herein, we aimed at maximizing the performance gain in the signal received by a hydrophone with respect to a singular source. By varying the signal delays for each source, it is possible to steer the transmission and obtain better efficiency in the reception. This work investigates, from an assumed knowledge of the underwater scenario, a way to choose suitable delays. The signals are digitally modulated in BPSK (Binary Phase Shift Keying) and BFSK (Binary Frequency Shift Keying), and transmitted by the array and by the single source with equivalent power. With computer simulations, the ideal direction is obtained from the lowest bit error rate (BER). The performance of the transmission array is compared to the single source. In addition, the effect of tidal variations is assessed. Finally, real experiments were carried out to verify the BER gain obtained in practice when using the steering angle obtained from simulations.