Patent ID: 8451093

Claim:
In a radio frequency identification system wherein at least one RFID tag generates a signal transmitted by backscatter modulation of a radio frequency signal, the signal generated by the at least one RFID tag comprising a sequence of symbols, an Interrogator comprising: a transmitter that transmits the radio frequency signal; and a receiver that receives the signal transmitted by the at least RFID tag and processes the received signal, said receiver including a symbol decoder that operates to decode the sequence of symbols in the received signal, wherein said symbol decoder generates a set of reference waveforms that have a phase inversion at least one every symbol boundary; wherein the symbols of the signal generated by the at least one RFID tag each have a predetermined symbol period, the set of reference waveforms extend over respective periods that correspond to a first extended processing window, and said symbol decoder decodes a given symbol by operating on portions of a component of the received signal that are received over the first extended processing window and on the set of reference waveforms, wherein the first extended processing window and the respective periods of the set of reference waveforms are all greater than said predetermined symbol period.