RFID Systems with Low Complexity Implementation and Pallet Coding Error Correction
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Accused Products
Abstract
Systems and methods for decoding data transmitted by RFID tags are disclosed. One embodiment of the invention includes an analyzer and equalizer configured to filter an input signal, an estimation block configured to obtain a baseband representation of the modulated data signal by mixing the filtered input signal with the carrier wave, and a coherent detector configured to perform phase and timing recovery on the modulated data signal in the presence of noise and to determine a sequence of data symbols.
8 Citations
39 Claims
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1-20. -20. (canceled)
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21. A receiver configured to decode a data signal modulated onto a carrier wave, where the phase and timing of the data signal is ambiguous, comprising:
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an analyzer and equalizer configured to filter an input signal; an estimation block configured to obtain a baseband representation of the modulated data signal by mixing the filtered input signal with the carrier wave; and a detector configured to perform timing recovery on the modulated data signal in the presence of noise and to determine a sequence of data symbols; wherein; the detector includes an interpolator that is configured to sample and interpolate the modulated data signal to generate a plurality of streams of signal samples possessing different symbol rates; the detector includes a correlator that is configured to; for each interpolated stream of signal samples; sum the interpolated stream over a half-symbol worth of signal samples; correlate the half-symbol sum with a pilot pattern; correlate the half-symbol sum with a preamble pattern; and delay match and sum the pilot pattern correlated result and the preamble pattern correlated result; and select the stream having the maximum correlation. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 31, 32)
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38. A system for interrogating radio frequency identification (RFID) tags, comprising:
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an exciter in a first location configured to activate an RFID tag; and a receiver in a second location for receiving information from an activated RFID tag; wherein the exciter and the receiver are configured to communicate via at least one wireless link; and wherein the receiver is configured to provide information to transmit to an activated RFID tag that is responsive to information decoded from signals received from the activated RFID tag to the exciter via the wireless link. - View Dependent Claims (39, 30)
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Specification