Systems and methods for providing an estimate of a population of passive Radio Frequency Identification (RFID) sensors in a coverage area of an RFID reader system are disclosed. In accordance with embodiments of this invention, the contention resolutions or results of each slot in an interrogation receive frame are determined. The contention resolutions are then used to determine the probabilities of different population estimates. A population estimate is then selected as the population based on the probability of the estimate meeting predetermined criteria.

According to one embodiment, according to one embodiment, an IC card executing a command from a processing apparatus includes a communication unit and a processing unit. The communication unit transmits/receives data to/from the processing apparatus. Upon receiving, through the communication unit, a first command requesting transmission of data in a first frame not including a start code or an end code, the processing unit transmits data in the first frame through the communication unit.

An arrangement, system and method for reducing the effect of interference at radio frequencies in an electronic price label system. The arrangement includes an electronic price label system, which includes a base station equipped with at least a radio transmitter and a radio receiver as well as a set of electronic price labels that receive and reflect back radio signals from the base station. The electronic price label system is connected to an electronic article surveillance system which includes a detector device which is able to detect electronic article surveillance tags, and which electronic article surveillance system further includes an activation device for changing a state of the detector device between an activated-state and a deactivated state. The electronic price label system is configured to start transmitting transmissions from base stations and/or electronic labels only when the detector device of the electronic article surveillance system is in the deactivated state.

Systems and methods for radio-frequency identification (RFID) tag communication are provided. One radio-frequency identification (RFID) tag includes a communication device configured to communicate with an RFID reader and an impedance element configured to change an variable impedance of the RFID tag. The RFID tag further includes at least one switch connected to the impedance element and a controller connected to the at least one switch and configured to control operation of the switch between open and closed states based on a control signal received from the RFID reader, wherein the variable impedance of the RFID tag is changed between a first modulating impedance value and a second modulating impedance value when the switch is changed between the open and closed states.

A fast RFID tag identifying method includes an encoding step for encoding a pair of bits to be expressed by an RFID tag into a silence code to be used in a transmitting step for the RFID tag. The silence code is arranged such that the superposition of a plurality of silence codes from a plurality of RFID tags is decoded into a set of pairs of bits to be expressed by the RFID tags.

In some aspects, material processing head can include a body; an antenna disposed within the body; a first tag, associated with a first consumable component, disposed within a flux communication zone of the body at a first distance from the antenna, the first tag having a first resonant frequency; and a second tag, associated with a second consumable component, disposed within the flux communication zone of the body at a second distance from the antenna, the second tag having a second resonant frequency that is different than the first resonant frequency, where the first and second resonant frequencies are tuned based upon at least one of: i) a difference between the first distance and the second distance; or ii) a characteristic (e.g., shape) of the flux communication zone in which the first tag and/or the second tag is disposed.

RFID readers may be configured to recover multiple, collided RFID tag signals. An RFID reader may receive a collided reply waveform including at least first and second tag responses. The reader may determine that the collided reply waveform contains multiple tag responses and recover the first and second tag responses from the collided reply waveform. The reader may first recover the first tag response, reconstruct the first tag response, and subtract the reconstructed first tag response from the collided reply waveform to form a modified tag response. The reader may then recover the second tag response from the modified tag response.

An electronic device for near field communication (NFC) device includes a front end unit configured to communicate with an external reader/writer device, the front end unit including a first memory adapted to store a check identifier, the check identifier configured to match one or more first identifiers, and a processing unit including a second memory configured to store one or more applications and one or more first identifiers, wherein a first identifier is assigned to one or more applications.

Systems and methods to determine motion parameters of physical objects using radio frequency identification (RFID) tags attached to the objects. In one embodiment, a method implemented in a radio frequency identification (RFID) system includes determining a motion parameter of the RFID tag based on detecting a Doppler frequency shift in a radio frequency signal received from the RFID tag.

A method for detecting receivers includes a step of detecting a receiver, in which step a general controller detects an adjustable receiver when a general antenna receives a secondary wave emitted by the adjustable receiver, followed by a reconfiguration step in which the general controller commands a controller of the detected adjustable receiver to switch to an interaction mode in which the impedance of the adjustable receiver is alternated between a first configuration impedance and a second configuration impedance in order to detect other receivers. The reconfiguration step is of a duration that is an order of magnitude higher than the duration of each alternation of the first and second configuration impedances.