Communication apparatus and method, antenna apparatus, and communication system

An antenna apparatus comprising:

• a coupled antenna element configured to receive a wireless communication via an antenna element of a communication apparatus positioned in the vicinity of the coupled antenna element;
• and
• a notification unit that notifies the communication apparatus that the communication apparatus is positioned in the vicinity of the coupled antenna element via a wireless connection with a detection circuitry of the communication apparatus,
• wherein the detection circuitry includes a surrounding environment sensor separate from the antenna element, the surrounding environment sensor being configured to wirelessly determine that the coupled antenna element is positioned in the vicinity of the communication apparatus when a change in a wireless parameter of an environment around the communication apparatus is detected, and
• the wireless communication via the antenna element is performed according to an adapted impedance on the bases of a detection result of the coupled antenna element.

A communication system comprising a communication apparatus and an antenna apparatus, wherein

• the antenna apparatus includes:
• a coupled antenna element configured to receive a wireless communication via an antenna element of a communication apparatus positioned in the vicinity of the coupled antenna element;
• and
• a notification unit that notifies the communication apparatus that the communication apparatus is positioned in the vicinity of the coupled antenna element, and
• the communication apparatus includes:
• detection circuitry configured to detect the coupled antenna element positioned in the vicinity of the communication apparatus;
• a controller configured to control adaptation of impedance on the basis of a detection result of the coupled antenna element by the detection circuitry;
• adaptation circuitry configured to adapt the impedance on the basis of control of the controller;
• and
• communication circuitry configured to perform wireless communication via the antenna element whose impedance has been adapted by the adaptation circuitry,
• wherein the detection circuitry includes a surrounding environment sensor separate from the antenna element, the surrounding environment sensor being configured to wirelessly determine that the coupled antenna element is positioned in the vicinity of the communication apparatus when a change in a wireless parameter of an environment around the communication apparatus is detected.