  Inductive coupling communication is one of the main methods of underwater
communication systems due to its excellent comprehensive performance. However,
the data transmission distance and operational power consumption need to be
further enhanced. In this paper, an underwater induction coupling communication
scheme based on power carrier technology is proposed to improve the
transmission speed and reduce the bit error rate. The microcontroller of STM32L
series with ultra-low power consumption was employed as the core of the system.
Through the construction and simulation of the communication channel, the
optimal parameters were determined. According to the circuit model of the power
carrier communication, the effect of different modulation and demodulation
methods to the signal transmission quality were discussed, which demonstrates
the superiority of Differential Phase Shift Keying (DPSK). With the
system-level low power design and onboard communication quality optimization,
the device was developed. The test results in the laboratory environment show
that the system can achieve efficient data communication with a rate of
115200bps and static power consumption as low as 660{\mu}A in the 700m channel.
This study provides a practical design approach for the high-speed
communication and Low-power operation of underwater communication systems.
