A robust underwater acoustic communication approach for pipeline transmission

As a special but important scenario, the critical requirement on robust and effective wireless acoustic communication through the pipeline is increased in the applications such as oil exploration and geological exploration. However, due to the complexity of the pipeline environment including strict band limitation, multi reflection and refraction from state-mixed transmission media of liquid, gas and solid, such a multipath channel is so sophisticated that relevant practical research is still a blank. In this article, after several field experiments, the characteristic of underwater pipeline channels is deeply tested and presented. Then a group of robust approaches mainly based on chirp signals for underwater communication through the pipeline is systematically proposed, where mainly including synchronization, timing and frequency offset estimation and signal to noise ratio (SNR) estimation for signal identification. Under conditions with center frequency 12 kHz and 1.1 kHz, both simulations and field experiments were performed. Their numerical results validate the effectiveness and robustness of the proposed approaches via the good and stable performance of detection, synchronization, estimation and demodulation under the ultra-low power consumption even at long distances.