Radio communication system, radio communication method, and data transmitter

• US 8,891,413 B2
• Filed: 08/03/2012
• Issued: 11/18/2014
• Est. Priority Date: 09/06/2011
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Ishizaki, Haruya, Mizuno, Masayuki
• Primary Examiner(s): Lai, Andrew
• Assistant Examiner(s): Qin, Zhiren
• Application Number:
  US13/566,107
• Publication Number:
  US 20130058263A1
• Time in Patent Office: 837 Days
• Field of Search: 370/278, 370/277, 370/276
• US Class Current: 370/278
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H04B 1/04 Circuits
• CPC Class Codes: H04B 1/3822 specially adapted for use in vehicles H04B1/3827 takes precedence
• CPC Class Codes: H04B 15/00 Suppression or limitation of noise or interference by means associated with receiver H04B1/10
• CPC Class Codes: H04B 2001/0408 with power amplifiers
• CPC Class Codes: H04B 7/24 for communication between two or more posts wireless communication networks H04W
• CPC Class Codes: H04W 4/80 Services using short range communication, e.g. near-field communication [NFC], radio-frequency identification [RFID] or low energy communication

Abstract

Disclosed is a radio communication system capable of reducing the cost for introducing a system utilizing RFID technology into a radio network environment. A radio communication system pertaining to the present invention includes a first radio equipment that transmits first data using a first radio wave; a data transmitter that outputs a second radio wave generated by modulating the first radio wave depending on second data which is an object for transmission; and a second radio equipment that receives the first and second radio waves and includes a separation and demodulation circuit that separates and demodulates the first data transmitted from the first radio equipment and the second data transmitted from the data transmitter included in the received radio waves. The data transmitter includes an amplifier for generating the second radio wave by amplifying the first radio wave.

Claims

1. A radio communication system comprising:

a first radio equipment that transmits first data as a first signal using a first radio wave;

a data transmitter that outputs a second radio wave as a second signal generated by modulating the first radio wave depending on second data which is an object for transmission; and

a second radio equipment that receives the first radio wave and the second radio wave and includes a separation and demodulation circuit that separates and demodulates the first data transmitted from the first radio equipment and the second data transmitted from the data transmitter included in the received radio waves,

wherein the data transmitter comprises an amplifier for generating the second signal by amplifying the first signal corresponding to the first radio wave, depending on the second data, and outputs the second signal as the second radio wave.

2. The radio communication system according to claim 1,

wherein, if a gain control signal corresponding to the second data is active, the amplifier amplifies the first signal amplitude so that the second radio wave acts as a disturbance to the first radio wave that is received by the second radio equipment.

3. The radio communication system according to claim 1,

wherein the data transmitter further comprises:

a signal antenna for receiving the first radio wave and transmitting the second radio wave; and

a duplexing element that separates a path for transferring the first signal corresponding to the received first radio wave to an input of the amplifier and a path for transferring the second signal to be transmitted as the second radio wave from an output of the amplifier to the antenna.

4. The radio communication system according to claim 1,

wherein the data transmitter further comprises:

a receiving antenna for receiving the first radio wave; and

a transmitting antenna for transmitting the second radio wave.

5. The radio communication system according to claim 4, wherein the receiving antenna and the transmitting antenna are configured as loop antennas and arranged so as to be rotated 90 degrees relative to each other in the same plane.

6. The radio communication system according to claim 1,

wherein the amplifier comprises:

a first amplifier that takes input of and amplifies the first signal;

a second amplifier that further amplifies the first amplified signal output from the first amplifier and outputs the second signal; and

a switch provided between the first amplifier and the second amplifier,

wherein the amplifier generates the second signal by switching the switch between a conducting state and a non-conducting state depending on the second data.

7. The radio communication system according to claim 1,

wherein the data transmitter further comprises:

an attenuator that attenuates the amplified second signal and generates a third signal, which is the amplified second signal output from the amplifier fed back via the attenuator,

wherein the amplifier receives input of the first signal and the third signal and generates the amplified second signal depending on the second data, and

wherein an amount of attenuation by the attenuator is determined based on an amplitude of the first signal and an amplitude of the third signal.

8. The radio communication system according to claim 7,

wherein the amplifier is configured as a differential amplifier that takes the respective inputs of the first signal and the third signal, and

wherein an amount of attenuation by the attenuator is determined so that the amplitude of the first signal equals the amplitude of the third signal.

9. The radio communication system according to claim 1, wherein the amplifier is provided with an amplitude limiting function that limits the power level of the generated second signal below a prescribed value.

10. The radio communication system according to claim 1, wherein the amplifier includes a harmonic elimination circuit that eliminates harmonics generated when generating the second signal.

11. The radio communication system according to claim 1, wherein the data transmitter further comprises a sensor for acquiring the second data which is the object for transmission.

12. The radio communication system according to claim 1, wherein the data transmitter further comprises a data storage unit for storing the second data which is the object for transmission.

13. The radio communication system according to claim 1, wherein the data transmitter externally acquires the second data which is the object for transmission via an input terminal.

14. The radio communication system according to claim 1,

wherein the data transmitter changes the bit error rate of the first radio wave by causing a disturbance to the first radio wave depending on the second data, and

wherein the second radio equipment demodulates the second data transmitted from the data transmitter based on changes in the bit error rate of the first radio wave.

15. The radio communication system according to claim 14, wherein the data transmitter changes the bit error rate of the first radio wave within a range lower than a radio standard value of bit error rate.

16. The radio communication system according to claim 14, wherein a modulation cycle of bit error rate for transmitting the second data is longer than a modulation cycle of the first radio wave for transmitting the first data.

17. The radio communication system according to claim 1, wherein the radio communication system includes a plurality of data transmitters and the second radio equipment distinguishes the source of the second data based on respective identification information added to the second data by each of the data transmitters.

18. A radio communication method for transmitting second data by a radio transmitter over a radio network comprising a first radio equipment that transmits first data and a second radio equipment that receives the first data, the radio communication method comprising the steps of:

transmitting the first data from the first radio equipment using a first radio wave;

at the data transmitter, modulating the first radio wave depending on the second data, thus generating a second radio wave, and outputting the second radio wave; and

at the second radio equipment, receiving the first radio wave and the second radio wave and separating and demodulating the first data transmitted from the first radio equipment and the second data transmitted from the data transmitter included in the received radio waves,

wherein the step of generating and outputting the second radio wave at the data transmitter comprises amplifying a first signal corresponding to the first radio wave depending on the second data, thus generating a second signal, and outputting the second signal as the second radio wave.

19. The radio communication method according to claim 18,

wherein, if a gain control signal corresponding to the second data is active, the amplifier amplifies the first signal amplitude so that the second radio wave acts as a disturbance to the first radio wave that is received by the second radio equipment.

20. A data transmitter comprising:

a modulation circuit that modulates a first radio wave being used in a radio network depending on transmission data which is an object for transmission, thereby generating a second radio wave that causes a disturbance to the first radio wave,

wherein the modulation circuit comprises an amplifier for generating a second signal by amplifying a first signal corresponding to the first radio wave, depending on the transmission data, and outputs the second signal as the second radio wave.

21. The data transmitter according to claim 20, further comprising:

a signal antenna for receiving the first radio wave and transmitting the second radio wave; and

a duplexing element that separates a path for transferring the first signal corresponding to the received first radio wave to an input of the amplifier and a path for transferring the second signal to be transmitted as the second radio wave from an output of the amplifier to the antenna.

22. The data transmitter according to claim 20, further comprising:

a receiving antenna for receiving the first radio wave; and

a transmitting antenna for transmitting the second radio wave.

23. The data transmitter according to claim 22, wherein the receiving antenna and the transmitting antenna are configured as loop antennas and arranged so as to be rotated 90 degrees relative to each other in the same plane.

24. The data transmitter according to claim 20,

wherein the amplifier comprises:

a first amplifier that takes input of and amplifies the first signal;

a second amplifier that further amplifies the first amplified signal output from the first amplifier and outputs the second signal; and

a switch provided between the first amplifier and the second amplifier,

wherein the amplifier generates the second signal by switching the switch between a conducting state and a non-conducting state depending on the transmission data.

25. The data transmitter according to claim 20, further comprising:

an attenuator that attenuates the amplified second signal and generates a third signal which is the amplified second signal output from the amplifier fed back via the attenuator,

wherein the amplifier receives input of the first signal and the third signal and generates the amplified second signal depending on the transmission data, and

wherein an amount of attenuation by the attenuator is determined based on an amplitude of the first signal and an amplitude of the third signal.

26. The data transmitter according to claim 25,

wherein the amplifier is configured as a differential amplifier that takes the respective inputs of the first signal and the third signal, and

wherein an amount of attenuation by the attenuator is determined so that the amplitude of the first signal equals the amplitude of the third signal.

27. The data transmitter according to claim 20,

wherein the amplifier is provided with an amplitude limiting function that limits the power level of the generated second signal below a prescribed value.

28. The data transmitter according to claim 20,

wherein the amplifier includes a harmonic elimination circuit that eliminates harmonics generated when generating the second signal.

29. The data transmitter according to claim 20, further comprising:

a sensor for acquiring the transmission data which is the object for transmission.

30. The data transmitter according to claim 20, further comprising:

a data storage unit for storing the transmission data which is the object for transmission.

31. The data transmitter according to claim 20, wherein the data transmitter externally acquires the transmission data which is the object for transmission via an input terminal.