Wireless communication system

A wireless communication system comprising:

• a locking and unlocking device configured to control locking and unlocking of a target, the locking and unlocking device being installed in the target, the locking and unlocking device including a device-side communication module configured to communicate a first signal having a first frequency band, the device-side communication module having a device-side antenna coil for communication;
• and
• a key unit configured to communicate with the locking and unlocking device and to command the locking and unlocking of the target by communicating with the locking and unlocking device, the key unit being mounted in the target and including a unit-side communication module that communicates the first signal, the unit-side communication module having a unit-side antenna coil for communication,
• wherein the key unit is mounted in the target such that a distance between the unit-side communication module and the device-side communication module is within a predetermined distance at which communication between the unit-side communication module and the device-side communication module is possible and that an axis of the unit-side antenna coil is parallel to an axis of the device-side antenna coil.