A system can be used for contactless communication of information between a first device and a second device, each having an antenna intended to be coupled via a near magnetic field. The first device includes a transmit chain having first circuitry configured to generate a digital data stream corresponding to the information to be transmitted, and second circuitry configured to generate a first amplitude-modulated and dithered signal in the antenna of the first device from this stream and from an application of a first dithering. The second device includes a receive chain having third circuitry configured to carry out a frequency transposition of a second amplitude-modulated and dithered signal originating from the first signal, with application of a second dithering synchronous with the first dithering.