Identification device detection using multiple signal combination
A method for determining whether an radio frequency identification (RFID) device is detected, includes: (a) selecting a plurality of different antenna patterns from a predetermined multiplicity of antenna patterns; (b) determining a plurality of binary results; (c) selecting, from a plurality of predetermined methods, a method for forming a logical combination; and (d) determining that the identification device is detected by forming a logical combination of the plurality of binary results according to the selected method. Each binary result is responsive to whether a respective communication link provides a respective signal having a respective amplitude exceeding a respective threshold. Each communication link is operative in accordance with at least one of the selected antenna patterns.
1. A method for determining whether a radio frequency identification device is detected, the method comprising:
selecting a plurality of different antenna patterns, each antenna pattern configured to receive a signal corresponding to an independent variable;
determining a plurality of results each responsive to whether a respective communication link provides a respective signal having a respective amplitude exceeding a respective threshold, each communication link operative in accordance with at least one of the selected antenna patterns;
selecting, from a plurality of predetermined logical combinations a logical combination; and
determining whether the radio frequency identification device is detected in accordance with the logical combination and in accordance with the plurality of results;
wherein R1, R2, R3, and R4 represent four results of the plurality of results, and at least one logical combination operates in accordance with the logical expression: (R1 OR R2) AND (R3 OR R4).
2. The method of claim 1 wherein each respective threshold is equal to a common threshold value.
3. The method of claim 1 wherein at least one of the respective communication links comprises:
a. a receiver; and
b. an antenna coupled to the receiver, wherein the antenna and the receiver cooperate in accordance with the respective antenna pattern.
4. The method of claim 1 wherein at least one of the respective communication links comprises:
a. a transmitter; and
b. an antenna coupled to the transmitter, wherein the antenna and the transmitter cooperate in accordance with the respective antenna pattern.
5. The method of claim 1 wherein each selected antenna pattern has a different polarization.
6. The method of claim 1 wherein each selected antenna pattern has a different direction of maximum effectiveness as an antenna.
7. The method of claim 1 wherein at least one logical combination operates in accordance with a logical OR of at least two of the plurality of results.
8. The method of claim 1 wherein at least one logical combination operates in accordance with a logical AND of at least two of the plurality of results.
9. A memory comprising indicia of instructions for performing the method of claim 1 by a data processing circuit.
10. A method for determining whether a radio frequency identification device is detected, the method comprising:
selecting a plurality of different antenna patterns, each antenna pattern configured to receive a signal corresponding to an independent variable;
determining a plurality of results each responsive to whether a respective communication link provides a respective signal having a respective amplitude exceeding a respective threshold, each communication link operative in accordance with at least one of the selected antenna patterns;
selecting, from a plurality of predetermined logical combinations a logical combination; and
determining whether the radio frequency identification device is detected in accordance with the logical combination and in accordance with the plurality of results;
wherein R1, R2, R3, and R4 represent four results of the plurality of results, and at least one logical combination operates in accordance with the logical expression: (R1 AND R2) OR (R3 AND R4).
11. A method for determining whether a radio frequency identification device is detected, the method comprising:
selecting a plurality of different antenna patterns, each antenna pattern configured to receive a signal corresponding to an independent variable;
determining a plurality of results each responsive to whether a respective communication link provides a respective signal having a respective amplitude exceeding a respective threshold, each communication link operative in accordance with at least one of the selected antenna patterns;
selecting, from a plurality of predetermined logical combinations a logical combination; and
determining whether the radio frequency identification device is detected in accordance with the logical combination and in accordance with the plurality of results;
wherein at least one logical combination operates in accordance with whether a sum of the plurality of results exceeds a predetermined quantity.
12. An object identification system comprising:
means for selecting a plurality of different antenna patterns, each antenna pattern configured to receive a signal corresponding to an independent variable;
means for determining a plurality of results each responsive to whether a respective communication link provides a respective signal having a respective amplitude exceeding a respective threshold, each communication link operative in accordance with at least one of the selected antenna patterns;
means for selecting, from a plurality of predetermined logical combinations, a logical combination; and
means for determining whether the radio frequency identification device is detected in accordance with the logical combination and in accordance with the plurality of results;
wherein R1, R2, R3, and R4 represent four results of the plurality of results, and at least one logical combination operates in accordance with the logical expression: (R1 OR R2) AND (R3 OR R4).
13. An object identification system comprising:
means for selecting a plurality of different antenna patterns, each antenna pattern configured to receive a signal corresponding to an independent variable;
means for determining a plurality of results each responsive to whether a respective communication link provides a respective signal having a respective amplitude exceeding a respective threshold, each communication link operative in accordance with at least one of the selected antenna patterns;
means for selecting, from a plurality of predetermined logical combinations, a logical combination; and
means for determining whether the radio frequency identification device is detected in accordance with the logical combination and in accordance with the plurality of results;
wherein R1, R2, R3, and R4 represent four results of the plurality of results, and at least one logical combination operates in accordance with the logical expression: (R1 AND R2) OR (R3 AND R4).