Data transmission via audio link on AM radio system is shown to be achievable by using Acoustic OFDM. We employ Acoustic OFDM to embed data onto audio contents that are then broadcast as AM radio signals. We tuned the parameters, and performed experiments. Text data as URL can be delivered to mobile phone through existing MF AM radio system and radios.

This paper presents a technology for short-range communications using sound wave, in which the modulated data signal can be transmitted in parallel with regular audio without significantly degrading the quality of the sound. The technology, which we call Acoustic OFDM, replaces the high frequency band of the audio signal with OFDM carriers, each of which is power-controlled according to the spectrum envelope of the original audio signal. It can provide data transmission of several hundreds bps. The implemented Acoustic OFDM system enables the transmission of short text messages from loud speakers to mobile devices at a distance of around 3 m.