DIFFERENTIAL BIPHASE SHIFT KEYING (DBPSK) USING AIRBORNE SOUND FOR DATA COMMUNICATION

摘要

We described a biphase shift keying (BPSK) using airborne sound for short-range data communication. Carrier recovery circuit which makes the reference phase becomes unnecessary, when differential PSK (DPSK) is used, and the circuitry is simplified. Acoustic wave propagates even in the opaque medium without receiving the electromagnetic interference. Acoustic transmission line can be simply composed only of a loudspeaker (SP) and a microphone (MIC). There is no necessity considering directional characteristics of the acoustic devices such as the SP and MIC, when the low frequency is used. As a result of data link experiment in 10 kHz carrier sound in the indoor space, the acoustic delay detection operated. The influence of the impulse response which originated from the inertia of the acoustic device like SP was also able to be reduced. Proposed acoustic data communication is effective for the communication to the remote manipulation robot, etc.