Design and realization of a QPSK modem module based on FPGA for underwater sensor node

Low-cost and high-performance underwater sensor nodes are important to the dense underwater wireless sensor networks. And the low-cost acoustic communication module is a necessary part for the underwater wireless sensor node. In this paper, a QPSK demodulation method by window mask is proposed. And an underwater acoustic module based on FPGA and QPSK is designed. The acoustic communication module is designed on the software platform QUARTUS II released by ALTERA Corporation. Then the acoustic communication module is realized on Cyclone II chip. Simulations and experiments show that the proposed demodulation method is valid. The developed communication module can process the signal´s modulation and demodulation.