Low frequency ultrasonic communication system low frequency ultrasonic communication method low frequency ultrasonic sending apparatus and low frequency ultrasonic receiving apparatus

摘要

A low frequency ultrasonic communication system according to the present invention includes a low frequency ultrasonic transmitter for transmitting data with a low frequency ultrasonic wave; and a low frequency ultrasonic receiver for processing a low frequency ultrasonic reception signal transmitted from the low frequency ultrasonic transmitter and recovering the data. Modulation in communication between the transmitter and the receiver uses a DPSK modulation scheme, and forward error correction coding is used for channel coding before modulation. It is possible to secure sufficient transmission distance and transmission efficiency.