Receiving apparatus and method for RFID reader

摘要

A receiving apparatus for an RFID reader estimates channel coefficients for each of a plurality of receiving antennas based on tag response signals received via a plurality of receiving antennas, compensates the tag response signals received via the plurality of receiving antennas based on the channel coefficients estimated for each of a plurality of channel estimators, combines the compensated tag response signals for each of the plurality of receiving antennas to generate a combined signal, and detect bits in the combined signal.

主权项

1. A receiving apparatus for an RFID reader which receives response signals backscatter-modulated by a tag, the receiving apparatus comprising:
a plurality of receiving antennas that receive the response signals; a plurality of channel estimators that estimate channel coefficients based on the signals received via the plurality of receiving antennas; a plurality of channel compensators that compensate the signals received via the plurality of receiving antennas based on the channel coefficients estimated by the plurality of channel estimators; a combiner that combines the compensated signals together to generate a combined channel signal; and a comparator that detects bits in the combined channel signal, wherein each response signal comprises a preamble signal, and the plurality of channel estimators estimate the channel coefficients by correlating the preamble signal in a preamble section received via the plurality of receiving antennas with an already known pilot signal, and wherein each of the plurality of channel estimators comprises:
an I channel correlator that calculates a correlation value of an I channel signal in the preamble section received via the corresponding receiving antenna with the pilot signal;a Q channel correlator that calculates a correlation value of a Q channel signal in the preamble section received via the corresponding receiving antenna with the pilot signal;an energy calculator that calculates correlation energy values by using the correlation value of the I channel signal and the correlation value of the Q channel signal; anda channel coefficient calculator that calculates a channel coefficient of the I channel signal and a channel coefficient of the Q channel signal by using a maximum value among the correlation energy values calculated by the energy calculator while the preamble section is received.