Communication system, tuner, and setting method

A tuner that carries out wireless communication with a mobile device, comprising:

• a setting processing unit configured to set a receiving frequency of an antenna and a demodulation frequency of a phase synchronization circuit on the basis of frequency information that is used in wireless communication between the mobile device and the tuner, the frequency information being included in a first signal from the mobile device;
• a setting information acquisition unit configured to acquire setting information corresponding to the frequency information, the frequency information being included in the first signal received by an engine switch, wherein
• the setting processing unit is configured to set the receiving frequency of the antenna on the basis of the setting information acquired by the setting information acquisition unit,
• the mobile device includes a signal generating unit configured to generate the first signal, a low frequency (LF) transponder response unit configured to modulate the first signal into LF-band radio waves and wirelessly transmit the first signal generated by the signal generating unit, and a radio frequency (RF) transmitting unit configured to modulate a response signal into RF-band radio waves and wirelessly transmit the response signal,
• the engine switch is configured to carry out bidirectional communication with the LF-band radio waves, and
• the LF transponder response unit is configured to carry out bidirectional communication with the engine switch when the mobile device is initially cataloged in an in-vehicle electronic device, and the first signal is transmitted from the mobile device to the in-vehicle electronic device when the mobile device is initially cataloged in the in-vehicle electronic device.

A setting method for a communication system including a mobile device and a tuner, comprising:

• generating a first signal with a use of a low frequency (LF) transponder response unit of the mobile device, the first signal including frequency information that is used in wireless communication between the mobile device and the tuner;
• wirelessly transmitting the first signal with the use of a radio frequency (RF) transmitting unit of the mobile device;
• setting a receiving frequency of an antenna and a demodulation frequency of a phase synchronization circuit on the basis of the frequency information with the use of the tuner, the frequency information being included in the first signal from the mobile device;
• and
• acquiring setting information corresponding to the frequency information, the frequency information being included in the first signal received by an engine switch, wherein
• the receiving frequency of the antenna is set on the basis of the acquired setting information,
• bidirectional communication with LF-band radio waves is carried out by the engine switch, and
• bidirectional communication with the engine switch is carried out by the LF transponder response unit when the mobile device is initially cataloged in an in-vehicle electronic device, and the first signal is transmitted from the mobile device to the in-vehicle electronic device when the mobile device is initial cataloged in the in-vehicle electronic device.