Tag identification system, tag reading apparatus, and method for determining sequence of tags

A tag reading apparatus for reading a plurality of tags sequentially passing by the apparatus, the tag reading apparatus at least comprising:

• at least two antennas for transmitting an interrogation signal to the plurality of tags passing by the coverage thereof and receiving a reply returned from each of the tags in response to the received interrogation signal;
• and
• a sequence determination unit which determines the sequence of the plurality of tags based on replies returned from the tags and received by the at least two antennas;
• further comprising a reply classification unit which classifies the replies received by each of the at least two antennas to determine whether the replies come from a single-region in which the received replies include only a reply returned from one of the plurality of tags or a multiple-region in which the received replies include replies returned from more than one of the plurality of tags, and sends the result of the classification to the sequence determination unit.

A method for determining the sequence in which a plurality of tags pass by a tag reading apparatus, comprising:

• an interrogation signal transmitting step for transmitting an interrogation signal from each of the at least two antennas of the tag reading apparatus to the plurality of tags within a coverage thereof,
• a reply receiving step for receiving replies returned from the plurality of tags in response to the received interrogation signal by each of the at least two antennas of the tag reading apparatus;
• and
• a sequence determination step for determining the sequence in which the plurality of tags passes by based on the received replies;
• further comprising a reply classification step for classifying the replies received by each of the at least two antennas to determine whether the replies come from a single-region in which the received replies include only a reply returned from one of the plurality of tags or a multiple-region in which the received replies include replies returned from more than one of the plurality of tags, and wherein the sequence determination step, the sequence in which the plurality of tags pass by is determined based on the result of the classification and the sequence in which the received replies are retuned.