Class / Patent application number | Description | Number of patent applications / Date published |
342125000 | With remote cooperating station | 12 |
20080284639 | METHOD FOR REDUCING RADIO RANGING ERRORS DUE TO CLOCK FREQUENCY OFFSETS - A method reduces errors in two-way ranging between transceivers due to a frequency offset. A first transceiver measures a time C | 11-20-2008 |
20090033545 | Wireless System Using Continuous Wave Phase Measurement for High-Precision Distance Measurement - A system and method for monitoring topological changes in a defined area. A grid of sensors is arranged in the area, with known distances between them. The sensors communicate wirelessly with a host computer, which individually addresses each sensor to instruct that sensor to be in an interrogate mode or responder mode. When a sensor is in interrogate mode, it measures distance from a neighboring sensor using radar (continuous wave phase difference) measurements. When a sensor is in responder mode, it receives, delays, and returns a signal received from a neighboring sensor. | 02-05-2009 |
20090207070 | METHOD AND APPARATUS FOR MEASURING DISTANCE IN A WIRELESS ENVIRONMENT - A method and apparatus for measuring a distance in a wireless environment are provided, in which a first device transmits a distance measurement signal to a second device and receives at least one response signal for the distance measurement signal from the second device, matches the received response signal with a reference signal to detect an earliest response signal, and calculates a time taken from the transmission of the distance measurement signal to the second device and the reception of the response signal from the second device using a peak value of the matched reference signal. | 08-20-2009 |
20100026558 | DISTANCE ESTIMATION - Improved distance estimation of a selected transmitter. An improved distance estimate from a target transmitter to a receiver is produced by assessing the target transmitter to determine transmit power, and combining this information with a propagation model, received signal strength, and reference signal strength indications. Target transmit power may be assessed through knowledge of the target device or device class, and/or transmit power reporting features of target wireless networks. The assessment may be made through looking up reported target device characteristics in a database, making inferences based on target device characteristics, or through standards-based diagnostic and/or reporting mechanisms. | 02-04-2010 |
20100277360 | HIGH-RESOLUTION, ACTIVE REFLECTOR RADIO FREQUENCY RANGING SYSTEM - A radio frequency ranging system is grounded in establishing and maintaining phase and frequency coherency of signals received by a slave unit from a master unit and retransmitted to the master unit by the slave unit. For a preferred embodiment of the invention, coherency is established through the use of a delta-sigma phase-lock loop, and maintained through the use, on both master and slave units, of thermally-insulated reference oscillators, which are highly stable over the short periods of time during which communications occur. A phase relationship counter is employed to keep track of the fractional time frames of the phase-lock loop as a function of the reference oscillator, thereby providing absolute phase information for an incoming burst on any channel, thereby enabling the system to almost instantaneously establish or reestablish the phase relationship of the local oscillator so that it synchronized with the reference oscillator. | 11-04-2010 |
20110006942 | CIRCUIT AND METHOD FOR DISTANCE MEASUREMENT BETWEEN TWO NODES OF A RADIO NETWORK - A circuit of a node of a radio network, and a method for distance measurement with a transceiver for receiving a first signal with a first frequency by downmixing to an intermediate frequency, with a phase measurement unit, which is set up to determine a first value of a first phase for a first frequency value of the first frequency. The transceiver is formed to transmit a second signal with a first frequency value of a second frequency for determining a first value of a second phase. The control circuit is set up to change the first frequency and the second frequency, in that a second frequency value of the first frequency and the first frequency value of the first frequency have a frequency difference, and whereby a second frequency value of the second frequency and the first frequency value of the second frequency have the frequency difference. The phase measurement unit is set up to determine a second value of the first phase for the second frequency value of the first frequency. The first frequency of the first signal and the second frequency of the second signal are spaced apart by an amount of the intermediate frequency. | 01-13-2011 |
20130154872 | METHOD AND A DEVICE FOR LOCATING AT LEAST ONE OBSTACLE IN A COMMUNICATIONS NETWORK, A CORRESPONDING COMPUTER PROGRAM - A method and apparatus are provided for locating an obstacle between a transmitter and a receiver. The method includes: determining at least one elliptical ring in which the obstacle is situated, the elliptical ring being defined by two confocal ellipses, having their focuses corresponding to the transmitter and to the receiver, each elliptical ring being associated with a physical echo generated by an obstacle; estimating a distance between the obstacle and a focus as a function of the separation between the confocal ellipses at the obstacle in a plane normal to the axis defined by the focuses so as to obtain a set of potential location zones for the obstacle in the elliptical ring; and lifting the ambiguity between the various potential location zones of the obstacle so as to deliver a location zone of the obstacle. | 06-20-2013 |
20140062761 | METHOD OF MEASURING DISTANCE BOUND USING RADIO FREQUENCY IDENTIFICATION (RFID) AND SYSTEM THEREOF - A tag decides a response based on a plurality of queries received from a reader, determines whether to transmit the response, transmits the response to the reader according to the results of the determination, and transmits a message authentication code including communication content to the reader. The reader calculates a consumed time period which is the time difference between a transmission time at which the queries are transmitted and a reception time at which the response is received, calculates an average consumed time period of the consumed time period, and measures a distance to the tag based on the average consumed time period. Accordingly, it is possible to check an attacker's intervention with a high probability, thereby improving distance measurement performance. Also, the tag may efficiently perform computing and communication. | 03-06-2014 |
20140232588 | HIGH-RESOLUTION, ACTIVE REFLECTOR RADIO FREQUENCY RANGING SYSTEM - A radio frequency ranging system is grounded in establishing and maintaining phase and frequency coherency of signals received by a slave unit from a master unit and retransmitted to the master unit by the slave unit. For a preferred embodiment of the invention, coherency is established through the use of a delta-sigma phase-lock loop, and maintained through the use, on both master and slave units, of thermally-insulated reference oscillators, which are highly stable over the short periods of time during which communications occur. A phase relationship counter is employed to keep track of the fractional time frames of the phase-lock loop as a function of the reference oscillator, thereby providing absolute phase information for an incoming burst on any channel, thereby enabling the system to almost instantaneously establish or reestablish the phase relationship of the local oscillator so that it synchronized with the reference oscillator. | 08-21-2014 |
20150054677 | METHOD AND APPARATUS FOR SENSING BOUNDARY BETWEEN MATERIALS - A method and apparatus for sensing boundaries between materials are provided. The method for sensing boundaries between materials comprises the steps of: fixing sensing modules in place; transmitting and receiving radio frequency signals; and analyzing radio frequency signals. The method enables real-time detection of positions of the boundaries between materials and handling and monitoring of changes in the boundary positions. The apparatus for sensing boundaries between materials comprises at least two sensing modules, or a radio frequency transmitting unit and a plurality of radio frequency signals receiving unit, or a plurality of radio frequency transmitting unit and a radio frequency signals receiving unit. The radio frequency signals are transmitted, received and analyzed by the radio frequency transmitting unit and the radio frequency signals receiving unit to determine the boundary positions and changes therein. | 02-26-2015 |
20150061920 | Time of arrival delay cancellations - The invention relates to a ranging system for measuring the distance between an interrogator and a transponder. The transponder includes: a signal receiver for receiving a challenge signal from an interrogator; a signal processor for processing the challenge signal and generating a response signal in response to the challenge signal; a buffer for storing the response signal generated by the signal processor; and a signal transmitter for sending the response signal stored in the buffer when the signal processor receives a ranging signal from the interrogator, wherein a time interval between the challenge signal and the ranging signal is known to both transponder and the interrogator. | 03-05-2015 |
20180024233 | BI-STATIC RADAR SYSTEM | 01-25-2018 |