Signal transmission system, interface device, and signal transmission method for superimposing a data signal on an electric power line

摘要

There is provided a signal transmission system including an information processing device and an interface device. The information processing device codes transmitted data into a code that does not include a direct-current component, and the information processing device transmits the code while superimposing the code on a direct-current power. A polarity of the code is inverted every half a period of a clock. The interface device detects a polarity inversion period of a signal received from the information processing device, and the interface device reproduces the clock based on the detection result.