Method and solution of data transmission from the transponder to the reader, especially in payment solutions with a mobile communication device
The method and solution can be mainly used for data transmission in cashless payment applications, especially those realized from the mobile phone while using RFID and/or NFC platform. The signals with different frequency are combined in antenna system (M) of the receiver ( 1 ) and transmitter ( 2 ) and then the carrier signal is separated from the result of the combined signals and the transmitted data are demodulated. The difference between the frequencies has a value, that corresponds to the size of the subcarrier frequency to which the receiver ( 1 ) is preset. During transmission the transformer connection coefficient can have the value k=0.2-0.001, while the antenna ( 3 ) of the receiver ( 2 ) is tuned narrowly to the transmitter's ( 2 ) frequency without considering the subcarrier frequency. The transmitter is preferably located on a memory card or on a card with a format and interface of a memory card, e.g. micro SD.
1. A method for transmitting data from a transmitter to a receiver via a transformer connection of inductions of a transmitter antenna and a receiver antenna, where a signal received at the receiver appears in the form of a carrier frequency and a subcarrier frequency that is modulated with data at a second frequency with respect to the carrier frequency, and where the receiver expects a standard signal structure with a subcarrier frequency, the method comprising:
the receiver transmitting a carrier signal at a carrier frequency to the transmitter;
the transmitter comprising an electromagnetic wave generator operating at a transmitter transmission frequency, said transmitter modulating the data on a transmitter signal at the transmitter transmission frequency and sending the modulated data to the receiver by actively transmitting said transmitter signal at said transmitter transmission frequency by sending an electromagnetic wave to the transmitter antenna, wherein the transmitter transmission frequency is different from the carrier frequency, and the difference between the transmitter transmission frequency and the carrier frequency corresponds to a subcarrier frequency that the receiver expects; and
the receiver receiving a received signal at the receiver antenna, the received signal being created by combining the carrier signal transmitted by the receiver with the modulated transmitter signal, the receiver separating the carrier signal from the received signal and demodulating the received signal as a combined signal having the carrier frequency and a modulated subcarrier frequency that is modulated with received data,
wherein the received signal is created by combining the electromagnetic wave received at the receiver from the transmitter only via mutual antenna induction of the transformer connection of the receiver's and the transmitter's antenna inductions and without the transmitter transmitting a signal at the subcarrier frequency.
2. The method of claim 1 , wherein the transmitter modulates the data on the transmitter signal by changing a transmitter transmission frequency signal phase.
3. The method of claim 1 , wherein the carrier signal has a frequency of 13.56 MHz±7 kHz, and the difference between the carrier frequency and the transmitter transmission frequency is defined relative to the carrier frequency.
4. The method of claim 1 , wherein the transmitter antenna is tuned to the transmitter transmission frequency, independent of transmission characteristics associated with the transmitter antenna for the subcarrier frequency.
5. The method of claim 1 , wherein the transmitter is in the form of a transponder and the receiver is formed by a reader on an RFID and/or NFC platform.
6. The method of claim 1 , wherein the transmitter is located in a mobile communication device.
7. The method of claim 1 , wherein the transmitter and transmitter antenna are located on a removable memory card that is adapted to be received into a slot in a mobile communication device.
8. The method of claim 1 , wherein the data are associated with a payment via a mobile communication device.
9. A method for transmitting data from a transmitter to a receiver, the transmitter having a transmitter antenna and the receiver having a receiver antenna, and where the receiver expects a standard signal structure with a subcarrier frequency, the method comprising:
the receiver transmitting a carrier signal at a carrier frequency;
the transmitter comprising an electromagnetic wave generator operating at a transmitter transmission frequency, said transmitter actively transmitting a transmitter signal at said transmitter transmission frequency by sending an electromagnetic wave to the transmitter antenna, wherein the transmitter transmission frequency is different from the carrier frequency, and the difference between the transmitter transmission frequency and the carrier frequency corresponds to a subcarrier frequency that the receiver expects;
the transmitter modulating the data on the transmitter signal at the transmitter transmission frequency and sending the modulated data to the receiver;
combining the electromagnetic wave of the carrier signal and the electromagnetic wave of the modulated transmitter signal in an antenna system of the receiver and the transmitter to form a combined signal; and
the receiver receiving the combined signal, and demodulating the received combined signal by separating the carrier signal from the combined signal to form a modulated subcarrier signal, and demodulating the transmitted data from the modulated subcarrier signal,
wherein the received combined signal is created only via mutual antenna induction of a transformer connection of the receiver's and the transmitter's antenna inductions and without the transmitter transmitting a signal at the subcarrier frequency.
10. The method of claim 9 , wherein the transmitter modulates the data on the transmitter signal by changing a transmitter transmission frequency signal phase.
11. The method of claim 9 , wherein the carrier signal has a frequency of 13.56 MHz±7 kHz, and the difference between the carrier frequency and the transmitter transmission frequency is defined relative to the carrier frequency.
12. The method of claim 9 , wherein the transmitter antenna is tuned to the transmitter transmission frequency, independent of transmission characteristics associated with the transmitter antenna for the subcarrier frequency.
13. The method of claim 9 , wherein the transmitter is in the form of a transponder and the receiver is formed by a reader on an RFID and/or NFC platform.
14. The method of claim 9 , wherein the transmitter is located in a mobile communication device.
15. The method of claim 9 , wherein the transmitter and transmitter antenna are located on a removable memory card that is adapted to be received into a slot in a mobile communication device.
16. The method of claim 9 , wherein the data are associated with a payment via a mobile communication device.
17. The method of claim 1 , wherein the received signal is created with a coupling coefficient of k=0.2 to 0.001.
18. The method of claim 1 , wherein during modulation in the transmitter the phase of the transmitted frequency is changed once per elementary time unit (etu) wherein the etu corresponds to a one bit time interval.
19. The method of claim 9 , wherein the received combined signal is created with a coupling coefficient of k=0.2 to 0.001.
20. The method of claim 9 , wherein during modulation in the transmitter the phase of the transmitted frequency is changed once per elementary time unit (etu) wherein the etu corresponds to a one bit time interval.