Patent application number | Description | Published |
20090267737 | RFID SYSTEM WITH DISTRIBUTED READERS - A system in one embodiment includes a plurality of Radio Frequency Identification (RFID) readers, each reader being capable of using a single antenna for both transmit and receive functions, wherein, during operation, one of the readers transmits and at least another of the readers receives a response to the transmission from an RFID device. A system in another embodiment includes a plurality of Radio Frequency Identification (RFID) readers, each reader having at least one antenna mounted on a housing thereof, wherein, during operation, the reader transmitting emits a signal sufficient to communicate with a battery assisted passive RFID device at a range of at least 20 meters. Additional systems and methods are also presented. | 10-29-2009 |
20120001732 | VARIABLE RATE PREAMBLE DETECTION USING RATIOMETRIC METHODS - A method for detecting a pattern in a signal according to one embodiment includes determining a time between symbol transitions in a signal derived from a radio frequency signal; determining ratios of relational times between consecutive symbol transitions; and comparing a sequence of the ratios to a target pattern for determining whether the sequence corresponds to the target pattern. Such methodology may also be implemented as a system using logic for performing the various operations. Additional systems and methods are also presented. | 01-05-2012 |
20120002758 | SUBCARRIER FREQUENCY ACQUISITION AND COMPLEX DEROTATION TO BASEBAND - A method for demodulating a radio frequency signal according to one embodiment includes receiving digital signals derived from a radio frequency signal; converting the digital signals to baseband signals; generating a frequency error signal using the baseband signals during an acquisition period; and shifting a frequency of the digital signals towards zero frequency error during the acquisition period using the frequency error signal, with the proviso that the digital signals are not phase locked during the shifting. Such methodology may also be implemented as a system using logic for performing the various operations. Additional systems and methods are also presented. | 01-05-2012 |
20120002760 | VARIABLE LENGTH CORRELATOR - A method for processing a signal derived from a radio frequency signal at some rate in a range of allowable data rates according to one embodiment includes downconverting an incoming signal derived from a radio frequency signal to complex near-baseband signals; processing the complex near-baseband signals in two data correlators corresponding to data 0 and data 1; and changing effective lengths of the correlators based on a symbol data rate of the incoming signal. Such methodology may also be implemented as a system using logic for performing the various operations. Additional systems and methods are also presented. | 01-05-2012 |
20120002762 | SINGLE OR DUAL COMPLEX SUBCARRIER DOWNCONVERSION - A method for subcarrier downconversion and data detection according to one embodiment includes determining whether to use an upper sideband frequency section of a complex downconverter output, a lower sideband frequency section of the complex downconverter output, or both sideband frequency sections of the complex downconverter output; and processing the output corresponding to the selected sideband frequency section or sections based on the determination, wherein the processing includes correlation and data detection. Such methodology may also be implemented as a system using logic for performing the various operations. Additional systems and methods are also presented. | 01-05-2012 |
20120002763 | HALF BIT CORRELATOR COMBINING FOR DATA DEMODULATION - A method for demodulating a data signal according to one embodiment includes processing baseband signals using multiple complex correlators each having a half-Tbit length; summing outputs of the complex correlators for a first data state; and differencing outputs of the complex correlators for a second data state. A system for demodulating a data signal according to one embodiment includes a correlator module having logic for: processing baseband signals using multiple complex correlators each having a half-Tbit length; summing outputs of the complex correlators for a first data state; and differencing outputs of the complex correlators for a second data state. Additional systems and methods are also presented. | 01-05-2012 |
20120002765 | AUTOMATIC GAIN CONTROL AND BASEBAND PREINTEGRATION TO REDUCE COMPUTATION REQUIREMENTS AT LOWER DATA RATES - A method for processing baseband signals according to one embodiment includes receiving I and Q baseband signals; and selectively reducing an amount of samples of the baseband signals to be processed in a correlator, wherein the reduction rate is based on a data rate of the baseband signals. A preintegrator module according to one embodiment includes an automatic gain control section for performing automatic gain control on I and Q baseband signals; a first preintegrator coupled to an output of the automatic gain control section, the first preintegrator being for selectively reducing an amount of samples in the I baseband signal based on a data rate of the I baseband signal; and a second preintegrator coupled to an output of the automatic gain control section, the second preintegrator being for selectively reducing an amount of samples in the Q baseband signal based on a data rate of the Q baseband signal. Additional systems and methods are also presented. | 01-05-2012 |
20120002766 | RSSI ESTIMATE ON VARIABLE LENGTH CORRELATOR OUTPUT - A method for estimating a strength of a radio frequency signal according to one embodiment includes receiving a correlator magnitude signal from a correlator module; performing a gain scaling on the correlator magnitude signal; and averaging the scaled correlator magnitude signal or value associated therewith to generate an output indicative of a strength of the signal. Such methodology may also be implemented as a system using logic for performing the various operations. Additional systems and methods are also presented. | 01-05-2012 |
20120002772 | DATA CLOCK RECOVERY LOOP JAM SET USING SUBCARRIER FREQUENCY ESTIMATE - A method for jam setting an initial frequency of a data clock recovery loop according to one embodiment includes generating a frequency error signal in a frequency error detector from sideband signals within a backscattered radio frequency signal, wherein the frequency error accumulates in a frequency error filter coupled to an output of the frequency error detector; at about an end of an acquisition period, freezing the accumulated frequency error in the frequency error filter; and using the frozen accumulated frequency error to jam set an initial frequency of a data clock recovery loop. Such methodology may also be implemented as a system using logic for performing the various operations. Additional systems and methods are also presented. | 01-05-2012 |
20120003938 | DYNAMIC SIGNAL DETECTION THRESHOLD - A method for setting a signal detection threshold according to one embodiment includes determining a measure of a noise floor in a signal derived from a radio frequency signal received by an antenna using a same circuit used to detect a subcarrier signal during transmitting and prior to sending a command to a transponder to respond; and setting a signal detection threshold above the noise floor. Such methodology may also be implemented as a system using logic for performing the various operations. Additional systems and methods are also presented. | 01-05-2012 |
20120003951 | END OF MODULATION DETECTION - A method for detecting an end of modulation in a backscattered radio frequency signal according to one embodiment includes generating a fast average of a magnitude or power of an incoming signal; generating a slow average of the magnitude or power of the incoming signal; determining an end of modulation based on a relationship between the fast and slow averages; and outputting an end of modulation signal upon determining the end of modulation. A system for detecting an end of modulation in a backscattered radio frequency signal according to one embodiment includes a window integrator for generating a fast moving average of a magnitude or power of an incoming signal; a leaky integrator for generating a slow moving average of the magnitude or power of the incoming signal; logic for determining an end of modulation when the fast moving average crosses below the slow moving average; and logic for outputting an end of modulation signal. Additional systems and methods are also presented. | 01-05-2012 |
20120056722 | RFID READER WITH CAMERA, VIDEO, AND/OR AUDIO CAPTURE DEVICE - A media capture device coupled to an RFID reader and/or antenna. A system in one embodiment includes a Radio Frequency Identification (RFID) reader; an antenna coupled to the RFID reader; and a media capture device coupled to at least one of the reader and the antenna. A method in another embodiment includes capturing media using a media capture device coupled to at least one of a Radio Frequency Identification (RFID) reader and an antenna coupled to the RFID reader upon occurrence of a trigger event. | 03-08-2012 |
20120223814 | RFID DEVICES, SYSTEMS AND METHODS FOR ACCURATE EQUIPMENT AND ASSET TRACKING - A method according to one embodiment includes conummicating with a radio frequency identification (RFID) tag coupled to a reusable transport item (RTI); and determining whether the RTI has passed a predetermined useful lifetime thereof based on information received from the RFID tag. A method according to one embodiment includes conummicating with a radio frequency identification (RFID) tag coupled to a reusable transport item (RTI); and determining both a horizontal and vertical position of the RTI. A method according to yet another embodiment includes communicating with a radio frequency identification (RFID) tag coupled to a reusable transport item (RTI); and performing an action based at least in part on at least one of a location and a determined inactivity of the RTI. | 09-06-2012 |
20130257598 | INTERFERENCE DETECTION AND MITIGATION IN RFID READERS AND SYSTEMS - One embodiment of the present invention includes a Radio Frequency Identification (RFID) reader configured to detect radio frequency (RF) interference in and/or outside a band of RFID operation. The RFID reader includes a receive channel for receiving incoming RF signals; and hardware for detecting interference in and/or outside a band of RFID operation. A method for mitigating radio frequency (RF) interference in and/or outside a band of RFID operation, according to one embodiment, includes detecting interference in and/or outside a band of RFID operation; and controlling an aspect of operation of the RFID reader for mitigating the detected interference. | 10-03-2013 |
20140253297 | RFID SYSTEMS AND METHODS FOR ASSOCIATING IMAGES OF DOCUMENTS WITH RFID TAG-RELATED DATA - A method for associating an image of a document with information relating to a radio frequency identification (RFID) tag, according to one embodiment, includes receiving information relating to an RFID tag, the information including at least one of a trip identifier, an identifier of the RFID tag, an identifier of a transport item, and a document identifier; receiving an image of a document; storing the image of the document; associating the image of the document with the information relating to the RFID tag; and storing the association of the image with the information relating to the RFID tag. | 09-11-2014 |