Patents by Inventor Ray Liu
Ray Liu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9538040Abstract: Various communication systems may benefit from physical layer watermarking. For example, active sensing for dynamic spectrum access may be performed using physical layer watermarking, such as watermarking based on channel effects and/or receiver distortion. A method may include, for example, obtaining an original signal to be transmitted to at least one receiver. The method may also include watermarking the original signal with at least one of authentication data or ancillary data to provide an enhanced signal. The watermarking can include a physical layer watermark. The physical layer watermark can be configured to emulate at least one a channel effect or a receiver distortion. The method can further include transmitting the enhanced signal to the at least one receiver.Type: GrantFiled: December 17, 2012Date of Patent: January 3, 2017Assignee: UNIVERSITY OF MARYLAND, COLLEGE PARKInventors: Nathan Goergen, Wan-Yi Lin, K. J. Ray Liu
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Publication number: 20160316454Abstract: A method of connecting devices to a network is provided. The method includes providing base stations connected to a network, and at each of the base stations, receiving probe signals from terminal devices. For each of the terminal devices, the base station calculates a signature waveform based on a time-reversed waveform of a channel response signal derived from the corresponding probe signal. For each of the terminal devices, the base station determines a downlink transmit signal for the terminal device based on the downlink data and the corresponding signature waveform, and transmits the downlink signals to the terminal devices. Several base stations have overlapping broadcast regions, several terminal devices are located within the overlapped broadcast regions, the base stations transmit the downlink signals using a same frequency band, and some downlink signals transmitted by base stations having overlapping broadcast regions also overlap in time.Type: ApplicationFiled: July 1, 2016Publication date: October 27, 2016Inventors: Yan Chen, Hang Ma, Yi Han, Hung-Quoc Duc Lai, K. J. Ray Liu
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Publication number: 20160315797Abstract: Time-reversal wireless communication includes: at a base station, receiving a probe signal from a terminal device; generating a signature waveform that is based on a time-reversed signal of a channel response signal derived from the probe signal; performing quadrature amplitude modulation (QAM) on a transmit signal to generate a quadrature amplitude modulated signal; and generating a transmission signal based on the quadrature amplitude modulated signal and the signature waveform.Type: ApplicationFiled: July 1, 2016Publication date: October 27, 2016Inventors: Yu-Han Yang, Yan Chen, K. J. Ray Liu
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Patent number: 9407306Abstract: Time-reversal wireless communication includes: at a base station, receiving a probe signal from a terminal device; generating a signature waveform that is based on a time-reversed signal of a channel response signal derived from the probe signal; performing quadrature amplitude modulation (QAM) on a transmit signal to generate a quadrature amplitude modulated signal; and generating a transmission signal based on the quadrature amplitude modulated signal and the signature waveform.Type: GrantFiled: April 25, 2014Date of Patent: August 2, 2016Assignee: Origin Wireless, Inc.Inventors: Yu-Han Yang, Yan Chen, K. J. Ray Liu
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Patent number: 9402245Abstract: A method of connecting devices to a network is provided. The method includes providing base stations connected to a network, and at each of the base stations, receiving probe signals from terminal devices. For each of the terminal devices, the base station calculates a signature waveform based on a time-reversed waveform of a channel response signal derived from the corresponding probe signal. For each of the terminal devices, the base station determines a downlink transmit signal for the terminal device based on the downlink data and the corresponding signature waveform, and transmits the downlink signals to the terminal devices. Several base stations have overlapping broadcast regions, several terminal devices are located within the overlapped broadcast regions, the base stations transmit the downlink signals using a same frequency band, and some downlink signals transmitted by base stations having overlapping broadcast regions also overlap in time.Type: GrantFiled: November 17, 2015Date of Patent: July 26, 2016Assignee: Origin Wireless, Inc.Inventors: Yan Chen, Hang Ma, Yi Han, Hung-Quoc Duc Lai, K. J. Ray Liu
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Publication number: 20160205569Abstract: In an asymmetric time-reversal wireless system, a base station includes an input circuit configured to, during a handshake period, receive a channel response signal derived from a probe signal sent from a first terminal device to the apparatus through multiple wireless propagation paths, and during an uplink transmission period, receive combined signals that include a signal from the first terminal device and a signal from a second terminal device. The base station includes a data processor configured to calculate a signature waveform for the first terminal device based on the channel response, and determine the signal sent from the first terminal device during the uplink transmission period based on the combined signals and the signature waveform for the first terminal device.Type: ApplicationFiled: August 14, 2014Publication date: July 14, 2016Inventors: Feng HAN, K.J. Ray LIU, Yan CHEN
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Publication number: 20160164669Abstract: A handshaking process for time-reversal wireless communication is provided. A first device receives a handshake signal transmitted from a second device through multiple propagation paths, the handshake signal including a preamble and a training sequence, in which the training sequence includes a sequence of symbols known to the first and second devices. A synchronization index is determined based on the preamble, and the training sequence in the handshake signal is identified based on the synchronization index. A channel response signal is determined based on the received training sequence, and a signature waveform that is a time-reversed signal of the channel response signal is generated. A transmission signal is generated based on transmit data and the signature waveform, in which the transmit data are data configured to be transmitted to the second device.Type: ApplicationFiled: February 11, 2016Publication date: June 9, 2016Inventors: Hang Ma, Yi Han, Yan Chen, Zoltan Safar, Feng Han, K. J. Ray Liu
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Publication number: 20160164767Abstract: A handshaking process for time-reversal wireless communication is provided. A first device receives a handshake signal transmitted from a second device through multiple propagation paths, the handshake signal including a preamble and a training sequence, in which the training sequence includes a sequence of symbols known to the first and second devices. A synchronization index is determined based on the preamble, and the training sequence in the handshake signal is identified based on the synchronization index. A channel response signal is determined based on the received training sequence, and a signature waveform that is a time-reversed signal of the channel response signal is generated. A transmission signal is generated based on transmit data and the signature waveform, in which the transmit data are data configured to be transmitted to the second device.Type: ApplicationFiled: February 11, 2016Publication date: June 9, 2016Inventors: Hang Ma, Yi Han, Yan Chen, Zoltan Safar, Feng Han, K. J. Ray Liu
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Patent number: 9313020Abstract: A handshaking process for time-reversal wireless communication is provided. A first device receives a handshake signal transmitted from a second device through multiple propagation paths, the handshake signal including a preamble and a training sequence, in which the training sequence includes a sequence of symbols known to the first and second devices. A synchronization index is determined based on the preamble, and the training sequence in the handshake signal is identified based on the synchronization index. A channel response signal is determined based on the received training sequence, and a signature waveform that is a time-reversed signal of the channel response signal is generated. A transmission signal is generated based on transmit data and the signature waveform, in which the transmit data are data configured to be transmitted to the second device.Type: GrantFiled: February 19, 2014Date of Patent: April 12, 2016Assignee: Origin Wireless, Inc.Inventors: Hang Ma, Yi Han, Yan Chen, Zoltan Safar, Feng Han, K. J. Ray Liu
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Publication number: 20160081060Abstract: A method of connecting devices to a network is provided. The method includes providing base stations connected to a network, and at each of the base stations, receiving probe signals from terminal devices. For each of the terminal devices, the base station calculates a signature waveform based on a time-reversed waveform of a channel response signal derived from the corresponding probe signal. For each of the terminal devices, the base station determines a downlink transmit signal for the terminal device based on the downlink data and the corresponding signature waveform, and transmits the downlink signals to the terminal devices. Several base stations have overlapping broadcast regions, several terminal devices are located within the overlapped broadcast regions, the base stations transmit the downlink signals using a same frequency band, and some downlink signals transmitted by base stations having overlapping broadcast regions also overlap in time.Type: ApplicationFiled: November 17, 2015Publication date: March 17, 2016Inventors: Yan Chen, Hang Ma, Yi Han, Hung-Quoc Duc Lai, K. J. Ray Liu
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Publication number: 20160018508Abstract: A time-reversal positioning system includes a storage storing first data representing channel impulse responses derived from probe signals sent from a plurality of positions and second data representing coordinates of the positions. A data processor determines a position of a terminal device based on the stored channel impulse responses and a time-reversed signal determined based on a time-reversed version of a channel impulse response that is estimated based on a channel probing signal sent from the terminal device.Type: ApplicationFiled: January 26, 2015Publication date: January 21, 2016Inventors: Yan Chen, Zhung-Han Wu, Yi Han, K. J. Ray Liu, Katherine Hall
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Publication number: 20160021670Abstract: A base station having an input module for receiving a probe signal sent from a terminal device, and a data processor for generating a signature waveform that is based on channel information derived from the probe signal, identifying data symbols intended to be transmitted to the terminal device, and modifying the data symbols based on the channel information. The modification of the data symbols is designed to reduce inter-symbol interference when the data symbols are received by the terminal device. The data processor generates a downlink signal based on the modified data symbols and the signature waveform. The base station generates a wide-band a radio frequency signal based on the downlink signal and transmits the radio frequency signal to the terminal device through a multipath channel such that a portion of the radio frequency signal intended for the terminal device focuses at the terminal device.Type: ApplicationFiled: February 6, 2015Publication date: January 21, 2016Inventors: Yu-Han Yang, K. J. Ray Liu
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Patent number: 9237140Abstract: A user associated with a first organization is authenticated, via a meeting server, for participation in an online session hosted by a second organization. It is determined, via the meeting server, that the first organization requires the user to accept a first policy. It is also determined, via the meeting server, that the second organization requires the user to accept a second policy. The first policy and the second policy are presented to the user for acceptance.Type: GrantFiled: March 7, 2013Date of Patent: January 12, 2016Assignee: Cisco Technologies, Inc.Inventors: Eric Lerner, Isaac Eleftheriadis, Ruixiang Ray Liu, Ming He
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Patent number: 9226304Abstract: A method of connecting devices to a network is provided. The method includes providing base stations connected to a network, and at each of the base stations, receiving probe signals from terminal devices. For each of the terminal devices, the base station calculates a signature waveform based on a time-reversed waveform of a channel response signal derived from the corresponding probe signal. For each of the terminal devices, the base station determines a downlink transmit signal for the terminal device based on the downlink data and the corresponding signature waveform, and transmits the downlink signals to the terminal devices. Several base stations have overlapping broadcast regions, several terminal devices are located within the overlapped broadcast regions, the base stations transmit the downlink signals using a same frequency band, and some downlink signals transmitted by base stations having overlapping broadcast regions also overlap in time.Type: GrantFiled: March 10, 2014Date of Patent: December 29, 2015Assignee: Origin Wireless, Inc.Inventors: Yan Chen, Hang Ma, Yi Han, Hung-Quoc Lai, K. J. Ray Liu
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Publication number: 20150312081Abstract: Time-reversal wireless communication includes: at a base station, receiving a probe signal from a terminal device; generating a signature waveform that is based on a time-reversed signal of a channel response signal derived from the probe signal; performing quadrature amplitude modulation (QAM) on a transmit signal to generate a quadrature amplitude modulated signal; and generating a transmission signal based on the quadrature amplitude modulated signal and the signature waveform.Type: ApplicationFiled: April 25, 2014Publication date: October 29, 2015Inventors: Yu-Han Yang, Yan Chen, K. J. Ray Liu
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Publication number: 20150257167Abstract: A method of connecting devices to a network is provided. The method includes providing base stations connected to a network, and at each of the base stations, receiving probe signals from terminal devices. For each of the terminal devices, the base station calculates a signature waveform based on a time-reversed waveform of a channel response signal derived from the corresponding probe signal. For each of the terminal devices, the base station determines a downlink transmit signal for the terminal device based on the downlink data and the corresponding signature waveform, and transmits the downlink signals to the terminal devices. Several base stations have overlapping broadcast regions, several terminal devices are located within the overlapped broadcast regions, the base stations transmit the downlink signals using a same frequency band, and some downlink signals transmitted by base stations having overlapping broadcast regions also overlap in time.Type: ApplicationFiled: March 10, 2014Publication date: September 10, 2015Applicant: Origin Wireless Communications, Inc.Inventors: Yan Chen, Hang Ma, Yi Han, Hung-Quoc Lai, K. J. Ray Liu
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Publication number: 20150236848Abstract: A handshaking process for time-reversal wireless communication is provided. A first device receives a handshake signal transmitted from a second device through multiple propagation paths, the handshake signal including a preamble and a training sequence, in which the training sequence includes a sequence of symbols known to the first and second devices. A synchronization index is determined based on the preamble, and the training sequence in the handshake signal is identified based on the synchronization index. A channel response signal is determined based on the received training sequence, and a signature waveform that is a time-reversed signal of the channel response signal is generated. A transmission signal is generated based on transmit data and the signature waveform, in which the transmit data are data configured to be transmitted to the second device.Type: ApplicationFiled: February 19, 2014Publication date: August 20, 2015Applicant: ORIGIN WIRELESS COMMUNICATIONS, INC.Inventors: Hang Ma, Yi Han, Yan Chen, Zoltan Safar, Feng Han, K. J. Ray Liu
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Publication number: 20150049792Abstract: In a time-reversal wireless system, a transceiver receives a combined signal that includes signals from a plurality of devices, each device sending a signal to the transceiver through multiple wireless propagation paths. Signals sent from each of the devices are estimated based on the combined signal and a signature waveform associated with the device. Interference associated with the estimated signal from each of the devices is determined based on the estimated signals from the devices. The signal sent from each of the devices is determined by subtracting the interference associated with the estimated signal associated with the device from the estimated signal associated with the device.Type: ApplicationFiled: August 16, 2013Publication date: February 19, 2015Applicant: Origin Wireless Communications, Inc.Inventors: Feng Han, K. J. Ray Liu
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Publication number: 20150049745Abstract: In an asymmetric time-reversal wireless system, a base station includes an input circuit configured to, during a hand-shake period, receive a channel response signal derived from a probe signal sent from a first terminal device to the apparatus through multiple wireless propagation paths, and during an uplink transmission period, receive combined signals that include a signal from the first terminal device and a signal from a second terminal device. The base station includes a data processor configured to calculate a signature waveform for the first terminal device based on the channel response, and determine the signal sent from the first terminal device during the uplink transmission period based on the combined signals and the signature waveform for the first terminal device.Type: ApplicationFiled: August 16, 2013Publication date: February 19, 2015Applicant: Origin Wireless Communications, Inc.Inventors: Feng Han, K. J. Ray Liu
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Patent number: 8827905Abstract: The present invention is a system and method of remote patient monitoring to allow a patient to initiate and activate sensing systems. In the system and method, standard parameters can be sensed, and the information can then be processed and sent to the physician or clinician. The clinician then has the ability to remotely configure or reconfigure the parameters of the sensing system so as to probe for more targeted information based on the initial sensed data.Type: GrantFiled: January 4, 2006Date of Patent: September 9, 2014Assignee: General Electric CompanyInventors: Steven Roehm, Ray Liu, Gopal B. Avinash