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Method of and device for transmitting serial data structures in systems for identifying information carriers

  • US 5,519,729 A
  • Filed: 05/06/1994
  • Issued: 05/21/1996
  • Est. Priority Date: 03/31/1992
  • Status: Expired due to Term
First Claim
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1. A method for inductively transmitting serial data structures in transponder identification systems comprising the steps of:

  • (a) transmitting a first carrier signal from an interrogator including modulating said first carrier signal with data using one of frequency modulation and phase modulation to transmit said data via electromagnetic waves of said first carrier signal;

    (b) detecting said first carrier signal at a transponder functioning as an information carrier;

    (c) demodulating said detected first carrier signal at said transponder to recover said data transmitted by said one of frequency modulation and phase modulation;

    (d) performing operations upon said data to effect one of decoding, reading and writing of said data in said transponder;

    (e) modulating a second carrier signal at said transponder using said data substantially immediately following said demodulation operation at said transponder and transmitting said modulated second carrier signal to effect time-parallel feed-back to said interrogator;

    (f) demodulating said modulated second carrier signal at said interrogator to recover said data;

    (g) comparing bitwise said data recovered at said interrogator and said data being used to presently modulate said first carrier signal;

    (h) halting said comparing in a manner of one of abruptly, at an end of a data word, and at an end of a data sequence in response to a negative data comparison result; and

    (i) repeating steps (a) through (h) until said data recovered at said interrogator and said data being used to presently modulate said first carrier signal are identical.

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