Method for transmitting data between a base station and a transponder

• US 7,277,478 B2
• Filed: 01/15/2003
• Issued: 10/02/2007
• Est. Priority Date: 02/01/2002
• Status: Expired due to Fees

• Current Assignee: Atmel Corporation (Microchip Technology Incorporated)
• Original Assignee: Atmel Germany GmbH (Microchip Technology Incorporated)
• Inventors: Friedrich, Ulrich, Fischer, Martin
• Primary Examiner(s): Edwards, Jr.; Timothy
• Application Number:
  US10/503,255
• Publication Number:
  US 20050094720A1
• Time in Patent Office: 1,721 Days
• Field of Search: 375/219, 375/220, 375/224, 455/67.11, 455/67.14
• US Class Current: 375/224
• CPC Class Codes: G06K 7/0008 General problems related to the reading of electronic memory record carriers, independent of its reading method, e.g. power transfer

Abstract

In known methods for the transmission of data, the data transmission rate is reduced by bit errors especially at high carrier frequencies. In the new method, the data transmission rate can be significantly increased due to the increased reliability in the data transmission by means of the integration of a test signal.

Claims

1. A method for the transmission of data between a base station (BS) and a transponder (TR) by means of an electromagnetic wave, in which an information packet (IP) is modulated onto this electromagnetic wave, which information packet comprises a data section (DA) with a data word and that is embodied as a sequence of bits, to the logic value of which a modulation state is respectively allocated, whereby respectively one bit of the bit sequence is transmitted in the time interval (TX) generated by means of one of two successive clock pulses, characterized in that

in addition to the clock pulses, a test signal (RFM) for the testing of the transmitted logic value is transmitted with a prescribed time duration (T1), during the time interval (TX), and

a time constant modulation state is allocated to the test signal (RFM).

2. The method according to claim 1, characterized in that the test signal (RFM) is inserted at the beginning of a time interval (TX).

3. The method according to claim 1, characterized in that the logic value of the bit transmitted in the time interval (TX) is derived from the change of the modulation state in a time point determined by the duration of the test signal (RFM).

4. The method according to claim 1, further comprising recognizing and correcting bit errors during the transmission of the data word.

5. A modulation control arrangement for carrying out the method according to claim 1, comprising a sample/hold unit (SH) in which is stored a first voltage value proportional to the time duration of the test signal (RFM), an integration unit (RC) that provides a second voltage value proportional to the duration of a charging current of a constant current source (IQ), a comparator (COMP) for comparing the first voltage value with the second voltage value, a modulation control unit (MOD_CON) for generating the modulation state of the electromagnetic wave dependent on an output signal (OUT) of the comparator (COMP) and the bit sequence of the data word (L2S) and for resetting the integration unit (RC).

6. A modulation control arrangement for carrying out the method according to claim 1, comprising a memory unit (TREF), in which a time point determined by the duration of the test signal (RFM) is stored, a multiplexer (MUX) that switches between time points that are allocated to the logic values of the bits that are to be transmitted and the time point allocated to the duration of the time interval (TX) and outputs the time point, a counter unit (COUNT) that provides a time point proportional value, a comparator (COMP) for comparing the value of the multiplexer (MUX) and the value of the counter (COUNT), and a modulation control unit for generating the modulation state of the electromagnetic wave dependent on an output signal (OUT) of the comparator (COMP) and the bit sequence of the data word (L2S).

7. The method according to claim 1, characterized in that, for the decoding of the received bit sequence, the logic value of the bit transmitted in the time interval (TX) is derived from its modulation state in a time point determined by the duration of the test signal (RFM).

8. The method according to claim 1, characterized in that a predetermined modulation state is allocated to the test signal (RFM) during the transmission of a data section.

9. A method of transmitting data between a base station and a transponder via an electromagnetic wave, comprising the steps:

a) providing successive clock pulses that define successive time intervals extending respectively from one to a next of said clock pulses;

b) providing a test signal including successive test signal pulses each respectively having a prescribed time duration during a respective time interval of said successive time intervals, wherein each said test signal pulse has a time constant modulation state during said prescribed time duration thereof;

c) providing a bit sequence of bits that form an information packet including a data section with a data word made up of a succession of said bits, wherein said bits respectively represent logic values and wherein each one of said logic values has a respective modulation state allocated thereto;

d) generating a modulation signal dependent on and responsive to said clock pulses, said test signal, and said bit sequence; and

e) modulating said modulation signal onto said electromagnetic wave to produce a modulated electromagnetic wave, and transmitting said modulated electromagnetic wave, such that a respective one of said test signal pulses and a respective one of said bits having a respective one of said logic values is transmitted during each respective one of said time intervals.

10. The method according to claim 9, wherein each one of said test signal pulses commences at a beginning of a respective one of said time intervals.

11. The method according to claim 9, further comprising receiving and decoding said modulated electromagnetic wave, and using said test signal pulses in said decoding to test accuracy of said logic values as transmitted in said modulated electromagnetic wave.

12. The method according to claim 9, further comprising receiving said modulated electromagnetic wave, and decoding said bit sequence from said modulated electromagnetic wave by determining said logic value of a respective one of said bits from a respective modulation state of said modulated electromagnetic wave at a time point determined by said prescribed time duration of said test signal pulse in the one of said time intervals during which said respective bit is transmitted.

13. The method according to claim 9, further comprising receiving said modulated electromagnetic wave, and decoding said bit sequence from said modulated electromagnetic wave by determining said logic value of a respective one of said bits from a respective change of a modulation state of said modulated electromagnetic wave at a time point determined by said prescribed time duration of said test signal pulse in the one of said time intervals during which said respective bit is transmitted.

14. The method according to claim 9, wherein said information packet further comprises a header section in which said prescribed time duration of said test signal pulses is defined.

15. The method according to claim 9, wherein said prescribed time duration is independent of and shorter than said time interval.

16. The method according to claim 9, wherein said time constant modulation state is a predetermined modulation state that is allocated to said test signal pulses of said test signal during transmitting of said data section.

17. The method according to claim 9, further comprising a step of recognizing and correcting a bit error during transmitting of said data word.

18. A modulation control arrangement for generating a modulated electromagnetic wave dependent on and responsive to a clock signal, a test signal and a bit sequence, said arrangement comprising:

a sample/hold unit adapted to store a first voltage value proportional to a prescribed time duration of a test signal pulse of said test signal;

a constant current source having an output adapted to provide a charging current;

an integration unit having an input connected to said output of said constant current source, and having an output adapted to provide a second voltage value proportional to a duration of said charging current of said constant current source;

a comparator having a comparator output, a first input connected to an output of said sample/hold unit, and a second input connected to said output of said integration unit, wherein said comparator is adapted to compare the first voltage value with the second voltage value and to produce a comparator output signal responsive thereto at said comparator output of said comparator; and

a modulation control unit having a first input connected to said comparator output of said comparator, a second input adapted to receive the clock signal, a third input adapted to receive the bit sequence, a reset output connected and adapted to provide a reset signal to a reset input of said integration unit, and a modulation signal output adapted to provide a modulation signal dependent on said comparator output signal and said bit sequence.

19. A modulation control arrangement for generating a modulated electromagnetic wave dependent on and responsive to a clock signal, a test signal and a bit sequence, said arrangement comprising:

a memory unit adapted to store a first time point determined by a duration of a test signal pulse of said test signal;

a multiplexer having an input connected to an output of said memory unit, and being adapted to switch between respective time points allocated to logic values of bits of said bit sequence and a time point allocated to a duration of a time interval determined by successive clock signal pulses of said clock signal, and having an output adapted to provide a selected time point;

a counter unit having an output adapted to provide a count value proportional to a time point;

a comparator having a comparator output, a first input connected to said output of said multiplexer, and a second input connected to said output of said counter unit, wherein said comparator is adapted to compare the selected time point at said output of said multiplexer with said count value at said output of said counter unit and to produce a comparator output signal responsive thereto at said comparator output of said comparator; and

a modulation control unit having a first input connected to said comparator output of said comparator, a second input adapted to receive the clock signal, a third input adapted to receive the bit sequence, a reset output connected and adapted to provide a reset signal to a reset input of said counter unit, and a modulation signal output adapted to provide a modulation signal dependent on said comparator output signal and said bit sequence.