Communication device and communication method

A communication system comprising:

• a first communication device;
• and
• a second communication device including
• a signal generator configured to
• receive a reception signal from the first communication device via a coil, and
• generate a transmission signal based on the reception signal, the transmission signal being synchronized with the reception signal,
• a phase adjuster circuitry configured to adjust a phase of the transmission signal based on the reception signal, and
• a first modulator configured to modulate the transmission signal.

A communication method comprising:

• receiving, with a coil of a communication device, a reception signal;
• detecting, with an amplitude detector unit of the communication device, an amplitude value VSW based on a voltage signal of the reception signal at a first end of the coil;
• generating, with a signal generator of the communication device, a transmission signal that is synchronized with the reception signal;
• and
• selecting, with a communication controller of the communication device, one of an active load modulation of the transmission signal or passive load modulation of the transmission signal based on the amplitude value VSW.