RFID reader to select code modules
First Claim
1. An RFID reader comprising:
- an antenna;
a memory to store a plurality of code modules;
a selector to select a selected one of the plurality of code modules, the selector to operate responsive to an automatically generated input indicating at least one of a plurality of conditions pertaining to an environment of the reader, the at least one condition being whether or not a number of tags in the environment exceeds a threshold, a different one of the plurality of code modules being selected depending on whether or not the number exceeds the threshold; and
a modulator to operate the antenna in accordance with the selected one of the plurality of code modules.
1 Assignment
0 Petitions
Accused Products
Abstract
RFID reader systems, chips, and methods deal with the occasional problem of environmental noise, such as interference from other RFID readers. An RF carrier at a center frequency is modulated, for causing an antenna to transmit a wireless signal to an RFID tag. One of a first and a second stored code modules is selected, such as by a selector. The code modules are each associated with a format, referenced to the center frequency, of a backscatter response of the RFID tag to the transmitted wireless signal, where the first code module is associated with a baseband modulation format, and the second code module is associated with a subcarrier modulation format. The transmitted wireless signal includes a command instructing the tag to backscatter according to the format of the selected code module. In addition, a wireless signal that is backscattered from the RFID tag in response to the command is demodulated according to the format of the selected code module.
-
Citations
24 Claims
-
1. An RFID reader comprising:
-
an antenna; a memory to store a plurality of code modules; a selector to select a selected one of the plurality of code modules, the selector to operate responsive to an automatically generated input indicating at least one of a plurality of conditions pertaining to an environment of the reader, the at least one condition being whether or not a number of tags in the environment exceeds a threshold, a different one of the plurality of code modules being selected depending on whether or not the number exceeds the threshold; and a modulator to operate the antenna in accordance with the selected one of the plurality of code modules. - View Dependent Claims (2, 3, 4, 5)
-
-
6. An RFID reader comprising:
-
an antenna; a memory to store a plurality of code modules; a selector to select one of the plurality of code modules, the selector to operate responsive to an automatically generated input indicating at least one of a plurality of conditions pertaining to an environment of the reader, the at least one condition being whether or not a number of readers in the environment exceeds a threshold, a different one of the plurality of code modules being selected depending on whether or not the number exceeds the threshold; and a modulator to operate the antenna in accordance with the selected one of the plurality of code modules. - View Dependent Claims (7, 8, 9, 10)
-
-
11. A method for a Radio Frequency Identification (RFID) reader to communicate with an RFID tag, comprising:
-
modulating a first RF carrier at a center frequency to provide a modulated RF carrier to cause an antenna to transmit to the RFID tag a transmitted wireless signal based on the modulated RF carrier; storing a first code module associated with a baseband modulation format and a second code module associated with a subcarrier modulation format, wherein the baseband modulation format and the subcarrier modulation format are referenced to the center frequency of a backscatter response of the RFID tag to the transmitted wireless signal; selecting one of the first stored code module and the second stored code module as a selected code module responsive to an automatically generated input indicating at least one of a plurality of conditions pertaining to an environment of the RFID reader, the at least one of the plurality of conditions being whether or not a number of tags in the environment exceed a threshold, a different one of the first and the second code modules being selected depending on whether or not the number exceeds the threshold, the transmitted wireless signal including a command instructing the RFID tag to backscatter according to the format associated with the selected code module; and demodulating, according to the format associated with the selected code module, a backscattered wireless signal from the RFID tag in response to the command. - View Dependent Claims (12, 13, 14, 15, 16, 17)
-
-
18. A method for a Radio Frequency Identification (RFID) reader to communicate with an RFID tag, comprising:
-
modulating a first RF carrier at a center frequency to provide a modulated RF carrier to cause an antenna to transmit to the RFID tag a transmitted wireless signal based on the modulated RF carrier; storing a first code module associated with a baseband modulation format and a second code module associated with a subcarrier modulation format, wherein the baseband modulation format and the subcarrier modulation format are referenced to the center frequency of a backscatter response of the RFID tag to the transmitted wireless signal; selecting one of the first stored code module and the second stored code module as a selected code module responsive to an automatically generated input indicating at least one of a plurality of conditions pertaining to an environment of the RFID reader, the at least one of the plurality of conditions being whether or not a number of readers in the environment exceed a threshold, a different one of the first and the second code modules being selected depending on whether or not the number exceeds the threshold, the transmitted wireless signal including a command instructing the RFID tag to backscatter according to the format associated with the selected code module; and demodulating, according to the format associated with the selected code module, a backscattered wireless signal from the RFID tag in response to the command. - View Dependent Claims (19, 20, 21, 22, 23, 24)
-
Specification