In environment of wireless sensor networks

due to strong electromagnetic field or the coexistence of short-distance wireless communication frequencies

short-distance wireless communications among sensor nodes may be disturbed and even be interrupted. Aiming at this problem

study a kind of short-range acoustic communication mode which modulates transimitted signals on sound waves and completes data communication among nodes through the propagation of sound waves in air. Firstly

design test system structure which is used to validate acoustic communication method

then introduces DPSK modulation and demodulation principle

related Matlab program flow

output and receiving amplifier circuit design. Finally

the acoustic communication experiments is carried out

it shows that the best distance of acoustic communication is 2 m in indoor environment and the best distance of sound communication is 5 m. The best baud rate are all 294 bps. The experimental data verifies that the designed acoustic communication method by this system is feasible.