Interdigital Technology Corporation

Symbol Technologies, LLC

Zebra Technologies Corporation

Infineon Technologies Ag

Alexander M Jacques

Fatih M Ozluturk

John Michael Kowalski

Gary R Lomp

David K Mesecher

Avi Silverberg

Michael J Luddy

Robert T Regis

Alexander Marra

Michael J Koch

Fatih M &Ouml;zl&uuml;t&uuml;rk

Benjamin J Bekritsky

Charles Burton Swope

Faith M Ozluturk

Fatih Ozukturk

Leonid L Kazakevich

Antonio Faraone

Raj Mani Misra

Joseph Boccuzzi

Stratis Gavnoudias

Yan Zhang

Camilo A Gaitan Parra

Richard Rizza

Yosef Nacson

Faith M Özlütürk

Michael Luddy

Robert E Regis

Systems and methods for enhanced fault tolerance for a radio frequency identification (RFID) phased array antenna are provided. The systems include a RFID reader that includes (i) a phased array antenna having N antenna elements; and (ii) a controller operatively connected to the phased array antenna. The controller is configured to (1) monitor a characteristic for each antenna element of a set of the N antenna elements; (2) based on the characteristic, detect a fault of a faulty antenna element of the set of the N antenna elements; and (3) responsive to detecting the fault of the faulty antenna element of the set of the N antenna elements, adjust a parameter of at least one other antenna element of the N antenna elements, wherein the parameter is a weight applied to a signal that is transmitted to or received at an antenna element.

Systems and methods for enhanced fault tolerance for RFID phased array antennas

Methods and devices for performing dynamic compensation of a phased array RFID reader are disclosed herein. An example method includes configuring an RFID reader having an antenna array to compensate for determined antenna element phase-shift errors. The method includes exciting a reference antenna element of the antenna array, emitting an emitted signal, receiving the emitted signal via a receiver antenna element of the antenna array, and generating a received signal. The method further includes determining, by a processor, a phase shift of the received signal relative to the emitted signal, and determining a phase-shift error. The method then includes configuring the RFID reader to compensate for the determined phase-shift error associated with the receiver antenna element in response to receiving an RFID tag signal.

Dynamic compensation of a phased array RFID reader

An RFID tag reading system and method accurately and rapidly determine true bearings of RFID tags associated with items in a controlled area. An RFID reader has an array of antenna elements and a plurality of RF transceivers. A controller controls the transceivers by steering a primary transmit beam over the controlled area to each tag, by steering a primary receive beam at a primary steering angle from each tag, by steering a plurality of secondary receive beams at different secondary steering angles that are offset from the primary steering angle by receiving secondary receive signals from each tag, and by processing the secondary receive signals to determine a true bearing for each tag. Bidirectional communication between the reader and a tag is conducted over a single inventory round in which the tag is read a plurality of times by the primary and the secondary receive beams.

System for and method of rapidly determining true bearings of radio frequency identification (RFID) tags associated with items in a controlled area

A radio frequency (RF) identification (RFID) tag reading system and method accurately determine true bearings of RFID tags associated with items in a controlled area. An RFID reader has an array of antenna elements and a plurality of RF transceivers. A controller controls the transceivers by steering a primary transmit beam over the controlled area by transmitting a primary transmit signal to each tag, and steering a primary receive beam at a primary steering angle by receiving a primary receive signal from each tag. The controller thereupon steers a plurality of secondary receive offset beams at different secondary steering angles that are offset from the primary steering angle by receiving secondary receive offset signals from each tag, and by processing the offset signals to determine a true bearing for each tag.

System for and method of accurately determining true bearings of radio frequency identification (RFID) tags associated with items in a controlled area

An RFID tag reading system and method estimate true bearings of RFID tags associated with items located in a scan zone directly underneath an overhead array of antenna elements. A controller energizes a plurality of diametrically opposite antenna elements to yield electric fields having polarizations, and switches each antenna element between mutually orthogonal polarizations. A primary transmit beam and a primary receive beam are steered at a primary steering angle over the scan zone, and a plurality of secondary receive beams are steered over the scan zone at different secondary steering angles that are offset from the primary steering angle by receiving secondary receive signals from each tag, and by processing the secondary receive signals to estimate a true bearing for each tag.

System and method of estimating true bearings of radio frequency identification (RFID) tags associated with items located directly underneath an overhead antenna array in a controlled area

A radio frequency identification (RFID) tag reading system having a phased antenna array accurately locates RFID tags in a controlled area, by steering an interrogating beam over the controlled area to interrogate the tags and generate return modulated RF signals. A primary receiver steers a primary receive beam at a primary steering angle that is fixed during each tag interrogation. A primary demodulator demodulates and reconstructs the received return modulated signals. A secondary receiver, independently of the primary receiver, steers a secondary receive beam at a plurality of secondary steering angles. A secondary correlator/demodulator demodulates the combined return modulated signals, and utilizes the reconstructed signal reconstructed by the primary demodulator at each of the secondary steering angles. Both the primary and the secondary receivers cooperate to accurately locate the same tag.

System for and method of locating radio frequency identification (RFID) tags associated with items in a controlled area

A subscriber unit for use in a multiple access spread-spectrum communication system includes a spread spectrum radio interface, responsive to a rate function signal from a base station, and first and second despreaders. The base station assigns the rate function spread-spectrum message channels and the first despreader recovers and modifies an information signal one of the spread spectrum message channels. The information channel mode is then modified for processing by the second despreader, with the second despreader supporting a different information signal rate. The subscriber unit has a capability of communicating with a dynamically changing a transmission rate of an information signal which includes multiple spread spectrum message channels. The system includes a closed loop power control system for maintaining a minimum system transmit power level for a radio carrier station and the subscriber units, and system capacity management for maintaining a maximum number of active subscriber units for improved system performance.

Code division multiple access (CDMA) communication system

A method for receiving at least one of a plurality of channels in a communication signal includes receiving a spread spectrum communication signal, demodulating the spread spectrum communication signal using a rake receiver and a pseudo-noise pilot signal for a selected channel, despreading the demodulated signal of a selected channel, performing a QPSK hard decision in association with a complex conjugate of the despread signal to produce a correction signal, and mixing the correction signal to a rake receiver output to remove relative phase error without an absolute phase reference, to produce a corrected signal.

Receiver for producing phase corrected signals

A wireless transmit/receive unit (WTRU) for carrier offset recovery. An adaptive matched filter produces a filtered signal. A rake receiver provides relative path values of multipath components. A mixer generates channel impulse response estimates. A channel despreader despreads the filtered signal using the pseudo-noise signal generated to produce a despread channel signal of the selected channel. A pilot channel despreader despreads the filtered signal using a pseudo-noise signal generator to produce a despread pilot signal of the pilot channel. A hard decision processor determines a symbol value of the despread channel signal. A complex conjugate processor generates a complex conjugate of the symbol value as a correction signal. A phase-locked loop produces a phase correction signal to recover carrier offset.

Wireless transmit/receive unit (WTRU) for carrier offset recovery

A base station for carrier offset recovery. An adaptive matched filter produces a filtered signal. A rake receiver provides relative path values of multipath components. A mixer generates channel impulse response estimates. A channel despreader despreads the filtered signal using the pseudo-noise signal generated to produce a despread channel signal of the selected channel. A pilot channel despreader despreads the filtered signal using a pseudo-noise signal generator to produce a despread pilot signal of the pilot channel. A hard decision processor determines a symbol value of the despread channel signal. A complex conjugate processor generates a complex conjugate of the symbol value as a correction signal. A phase-locked loop produces a phase correction signal to recover carrier offset.

Base station for carrier offset recovery

A receiver employing CDMA techniques estimates background noise based on a periodically updated code. The transmitted signal includes a periodically updated code of a predetermined type and wherein the received signal has CW interference in addition to the transmitted signal. The decision circuit determines if a value representing the likelihood of detection of the code exceeds a predetermined threshold. In the case of a pilot signal not being detected within a predetermined time period which corresponds to code update period, the background noise estimator obtains a new background estimation.

User equipment for detecting short codes

A configurable cellular terminal engine (CTE) in accordance with an exemplary embodiment of this invention is configurable by an external agent (e.g., microcontroller, DSP, or state machine) to suit the particular requirements of different spread spectrum systems. In an exemplary embodiment, the CTE comprises on a chipset a modem unit and a channel codec unit. The modem unit has a front end unit for coupling to an antenna; a matched filter searchers unit coupled at least to the front end unit; a searchers unit coupled to at least the front end unit; a finger processing unit coupled to the front end unit; a parameter estimation processor unit coupled to at least the finger processing unit and the searchers unit; and a transmitter unit. The channel codec unit has a channel decoder unit coupled at least to the finger processing unit; and a channel encoder coupled at least to the transmitter unit.

Configurable terminal engine

A receiver and base station for producing phase-corrected channel signals. An adaptive matched filter produces a filtered signal by using a weighting signal. A rake receiver produces a filter weighting signal using a pseudo-noise signal generator. A channel despreader despreads the filtered signal using the pseudo-noise signal generated to produce a despread channel signal of the selected channel. A pilot channel despreader despreads the filtered signal using a pseudo-noise signal generator to produce a despread pilot signal of the pilot channel. A hard decision processor receives the despread channel signal of the selected channel and produces a correction signal. A phase-locked loop utilizes at least the despread pilot signal and produces a phase correction signal which is applied to produce phase-corrected channel signals.

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Kings Park, NY, United States of America

Alexander M Jacques