Implementation of an ultrasonic wireless communication system through metal barrier based on DSP

Many industrial applications need the technology of data transmission through metal barrier. Conventional wireless communication based on electromagnetic wave cannot be applied due to the Faraday shielding effect. This paper introduces the key technologies of high reliability bidirectional communication through a metal wall. There are the digital amplitude modulation when the data transmits from the transmitter to the receiving end and the data transmission based on impedance modulation from the receiving end to the transmitter. Two DSP platforms for processing information include encoding, modulation, demodulation and decoding on both sides are implemented. The upper-computer at both sides with a SCI Interface for sending and collecting data. The DSP will process the data and transmit it for modulating the carrier once it receives the information. In the same way, the DSP will process that and transmit it to the upper-computer once it get a byte data for a reverse process. This system acts as a communication platform with a reliable communication at data rates up to 10 kbps, which indicates that the prototype system is very practical and valuable.