Patents by Inventor Xiaoru Zhang
Xiaoru Zhang 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: 8170494Abstract: A transceiver including a transmit modulator and a receiver. The modulator may accept a channel selection input, a first modulation input, a second modulation input, and an amplitude input. During transmit time slots, the modulator may generate a modulated output having a carrier frequency selected by the channel selection input. The carrier frequency may be frequency modulated by the first modulation inputs, phase modulated by the second modulation input, and amplitude modulated by the amplitude input. During receive time slots, the modulator may generate a carrier frequency selected by the channel selection input and offset by the first modulation input. The modulator may alternate between providing modulated transmit signals during transmit time slots and providing a local oscillator for the receiver during receive time slots.Type: GrantFiled: July 14, 2008Date of Patent: May 1, 2012Assignee: Qualcomm Atheros, Inc.Inventors: Paul J. Husted, Soner Ozgur, Xiaoru Zhang
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Patent number: 8081878Abstract: A system and method for wirelessly transmitting both real-time data streams and remote control signals is described. A first transceiver can be used for detecting remote control signals associated with an end device (e.g. a television), transforming these remote control signals into wireless signals, and transmitting the wireless signals. A second transceiver can be used for receiving the wireless signals and transforming the wireless signals into the recreated remote control signals. The recreated remote control signals can then be sent to a source device (e.g. a DVD player). Because wireless signals are used (instead of infrared (IR) signals, for example), the source device can be outside the line of sight of the end device and still respond to the remote control signals.Type: GrantFiled: March 23, 2009Date of Patent: December 20, 2011Assignee: Qualcomm Atheros, Inc.Inventors: Xiaoru Zhang, William J. McFarland, Atul Divekar
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Publication number: 20100316175Abstract: Techniques are disclosed for detecting a packet. One technique includes sampling a received signal to produce a sequence of samples wherein the sequence of samples includes a plurality of subsequences of samples; cross correlating the subsequences of samples with a known form of the subsequence to produce cross correlations; self correlating the cross correlations to produce a plurality of self correlations; summing the self correlations; and processing the sum of the self correlations.Type: ApplicationFiled: May 21, 2010Publication date: December 16, 2010Inventors: Chaohuang Zeng, Jeffrey M. Gilbert, Won-Joon Choi, Xiaoru Zhang
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Patent number: 7835456Abstract: Spurs cause significant problems with signal detecting, amplifier gain adjustment, and signal decoding. Various techniques can be used to mitigate the effects of spurs on a received signal. Generally, these techniques work by either canceling or ignoring the spurs. For example, a pilot mask can be used to ignore pilot information in one or more sub-channels. A Viterbi mask can determine the weighting given to bits in a sub-channel based on spur and data rate information. Channel interpolation can compute a pseudo channel estimate for a sub-channel known to have a spur location can be computed by interpolating the channel estimates of adjacent good sub-channels. Filtering of the received signal using a low-pass filter, a growing box filter, or a low-pass filter with self-correlation can be used to cancel a spur.Type: GrantFiled: December 6, 2007Date of Patent: November 16, 2010Assignee: Atheros Communications, Inc.Inventors: Won-Joon Choi, Jeffrey M. Gilbert, Yi-Hsiu Wang, Xiaoru Zhang
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Patent number: 7751520Abstract: Techniques are disclosed for detecting a packet. One technique includes sampling a received signal to produce a sequence of samples wherein the sequence of samples includes a plurality of subsequences of samples; cross correlating the subsequences of samples with a known form of the subsequence to produce cross correlations; self correlating the cross correlations to produce a plurality of self correlations; summing the self correlations; and processing the sum of the self correlations.Type: GrantFiled: September 17, 2003Date of Patent: July 6, 2010Assignee: Atheros Communications, Inc.Inventors: Chaohuang Zeng, Jeffrey M. Gilbert, Won-Joon Choi, Xiaoru Zhang
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Publication number: 20090311979Abstract: A modulation system comprising a signal processing unit and a modulator. The signal processing unit may generate a low frequency modulator signal, a high frequency modulator signal, and a modulator amplitude control signal. The modulator may generate a modulated signal for transmission via a wireless network based, at least in part, on the low frequency modulator signal, the high frequency modulator signal, and the modulator amplitude control signal. The signal processing unit comprises a delay compensation unit for delaying the generation of the high frequency modulator signal and the modulator amplitude control signal based, at least in part, on signal generation and modulation path delays associated with the low frequency modulator signal to substantially align the modulator signals at the output of the modulation system.Type: ApplicationFiled: July 14, 2008Publication date: December 17, 2009Applicant: Atheros Communications, Inc.Inventors: Paul J. Husted, William W. Si, David J. Weber, Xiaoru Zhang
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Publication number: 20090311972Abstract: A transceiver including a transmit modulator and a receiver. The modulator may accept a channel selection input, a first modulation input, a second modulation input, and an amplitude input. During transmit time slots, the modulator may generate a modulated output having a carrier frequency selected by the channel selection input. The carrier frequency may be frequency modulated by the first modulation inputs, phase modulated by the second modulation input, and amplitude modulated by the amplitude input. During receive time slots, the modulator may generate a carrier frequency selected by the channel selection input and offset by the first modulation input. The modulator may alternate between providing modulated transmit signals during transmit time slots and providing a local oscillator for the receiver during receive time slots.Type: ApplicationFiled: July 14, 2008Publication date: December 17, 2009Applicant: Atheros Communications, Inc.Inventors: Paul J. Husted, Soner Ozgur, Xiaoru Zhang
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Patent number: 7529486Abstract: A system and method for wirelessly transmitting both real-time data streams and remote control signals is described. A first transceiver can be used for detecting remote control signals associated with an end device (e.g. a television), transforming these remote control signals into wireless signals, and transmitting the wireless signals. A second transceiver can be used for receiving the wireless signals and transforming the wireless signals into the recreated remote control signals. The recreated remote control signals can then be sent to a source device (e.g. a DVD player). Because wireless signals are used (instead of infrared (IR) signals, for example), the source device can be outside the line of sight of the end device and still respond to the remote control signals.Type: GrantFiled: August 3, 2005Date of Patent: May 5, 2009Assignee: Atheros Communications, Inc.Inventors: Xiaoru Zhang, William J. McFarland, Atul Divekar
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Patent number: 7463704Abstract: A wireless local area network (WLAN) system can have multiple antennas to improve signal detection and decoding. A WLAN receiver in such a system includes multiple amplifiers that can appropriately size an incoming signal and an automatic gain control unit to process the received incoming signals. The amplifiers of a chain of the WLAN receiver, i.e. an antenna and associated receiver components, can be adjusted with computed gains. To optimize the wireless system detection and decoding, the automatic gain control unit can advantageously compute these gains for each amplifier in the WLAN receiver.Type: GrantFiled: July 1, 2004Date of Patent: December 9, 2008Assignee: Atheros Communications, Inc.Inventors: Ardavan Maleki Tehrani, Xiaoru Zhang, Paul J. Husted, Jeffrey M. Gilbert
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Publication number: 20080123761Abstract: Spurs cause significant problems with signal detecting, amplifier gain adjustment, and signal decoding. Various techniques can be used to mitigate the effects of spurs on a received signal. Generally, these techniques work by either canceling or ignoring the spurs. For example, a pilot mask can be used to ignore pilot information in one or more sub-channels. A Viterbi mask can determine the weighting given to bits in a sub-channel based on spur and data rate information. Channel interpolation can compute a pseudo channel estimate for a sub-channel known to have a spur location can be computed by interpolating the channel estimates of adjacent good sub-channels. Filtering of the received signal using a low-pass filter, a growing box filter, or a low-pass filter with self-correlation can be used to cancel a spur.Type: ApplicationFiled: December 6, 2007Publication date: May 29, 2008Inventors: Won-Joon Choi, Jeffrey M. Gilbert, Yi-Hsiu Wang, Xiaoru Zhang
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Patent number: 7321631Abstract: Spurs cause significant problems with signal detecting, amplifier gain adjustment, and signal decoding. Various techniques can be used to mitigate the effects of spurs on a received signal. Generally, these techniques work by either canceling or ignoring the spurs. For example, a pilot mask can be used to ignore pilot information in one or more sub-channels. A Viterbi mask can determine the weighting given to bits in a sub-channel based on spur and data rate information. Channel interpolation can compute a pseudo channel estimate for a sub-channel known to have a spur location can be computed by interpolating the channel estimates of adjacent good sub-channels. Filtering of the received signal using a low-pass filter, a growing box filter, or a low-pass filter with self-correlation can be used to cancel a spur.Type: GrantFiled: July 31, 2006Date of Patent: January 22, 2008Assignee: Atheros Communications, Inc.Inventors: Won-Joon Choi, Jeffrey M. Gilbert, Yi-Hsiu Wang, Xiaoru Zhang
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Patent number: 7129884Abstract: A radar detection technique in a WLAN device can include a short pulse detection technique and a long pulse detection technique that can be performed using multiple receive chains. Short pulse detection is particularly effective when the incoming signal includes one or a limited number of main pulses and some residual pulses. In contrast, long pulse detection is particularly effective when the incoming signal is longer, thereby allowing various characteristics of the incoming signal to be accurately measured.Type: GrantFiled: July 1, 2004Date of Patent: October 31, 2006Assignee: Atheros Communications, Inc.Inventors: Ardavan Maleki Tehrani, Xiaoru Zhang, Paul J. Husted, Jeffrey M. Gilbert
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Patent number: 6954171Abstract: Radar Pulse detection and radar signal length detection are used to detect and provide information for identifying radar signals. Pulse detection estimates a radar pulse size when it is too short for meaningful measurement. Pulse detection identifies a radar by identification of an in-band pulse without a communication or data packet encoded therein, or a communication error is detected with the in-band pulse. Signal length detection counts the length of a received signal after the received signal exceeds a radar threshold. The count identifies the received signal length upon drop of the power. The signal is identified as a radar when the power drops before a PHY error occurs, or when the power drop occurs after a PHY error and a delay time equivalent to the shortest radar signal. A radar signal is also identified upon a timeout wait for a power drop after a PHY error.Type: GrantFiled: April 2, 2003Date of Patent: October 11, 2005Assignee: Atheros Communications, Inc.Inventors: Paul Husted, William J. McFarland, Xiaoru Zhang, John Thompson
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Patent number: 6891496Abstract: Radar Pulse detection and radar signal length detection are used to detect and provide information for identifying radar signals. Pulse detection estimates a radar pulse size when it is too short for meaningful measurement. Pulse detection identifies a radar by identification of an in-band pulse without a communication or data packet encoded therein, or a communication error is detected with the in-band pulse. Signal length detection counts the length of a received signal after the received signal exceeds a radar threshold. The count identifies the received signal length upon drop of the power. The signal is identified as a radar when the power drops before a PHY error occurs, or when the power drop occurs after a PHY error and a delay time equivalent to the shortest radar signal. A radar signal is also identified upon a timeout wait for a power drop after a PHY error.Type: GrantFiled: May 3, 2002Date of Patent: May 10, 2005Assignee: Atheros Communications, Inc.Inventors: Paul Husted, William J. McFarland, Xiaoru Zhang, John Thompson
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Publication number: 20050059366Abstract: Spurs cause significant problems with signal detecting, amplifier gain adjustment, and signal decoding. Various techniques can be used to mitigate the effects of spurs on a received signal. Generally, these techniques work by either canceling or ignoring the spurs. For example, a pilot mask can be used to ignore pilot information in one or more sub-channels. A Viterbi mask can determine the weighting given to bits in a sub-channel based on spur and data rate information. Channel interpolation can compute a pseudo channel estimate for a sub-channel known to have a spur location can be computed by interpolating the channel estimates of adjacent good sub-channels. Filtering of the received signal using a low-pass filter, a growing box filter, or a low-pass filter with self-correlation can be used to cancel a spur.Type: ApplicationFiled: September 16, 2003Publication date: March 17, 2005Inventors: Won-Joon Choi, Jeffrey Gilbert, Yi-Hsiu Wang, Xiaoru Zhang
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Publication number: 20030214430Abstract: Radar Pulse detection and radar signal length detection are used to detect and provide information for identifying radar signals. Pulse detection estimates a radar pulse size when it is too short for meaningful measurement. Pulse detection identifies a radar by identification of an in-band pulse without a communication or data packet encoded therein, or a communication error is detected with the in-band pulse. Signal length detection counts the length of a received signal after the received signal exceeds a radar threshold. The count identifies the received signal length upon drop of the power. The signal is identified as a radar when the power drops before a PHY error occurs, or when the power drop occurs after a PHY error and a delay time equivalent to the shortest radar signal. A radar signal is also identified upon a timeout wait for a power drop after a PHY error.Type: ApplicationFiled: May 3, 2002Publication date: November 20, 2003Inventors: Paul Husted, William J. McFarland, Xiaoru Zhang, John Thomson
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Publication number: 20030206130Abstract: Radar Pulse detection and radar signal length detection are used to detect and provide information for identifying radar signals. Pulse detection estimates a radar pulse size when it is too short for meaningful measurement. Pulse detection identifies a radar by identification of an in-band pulse without a communication or data packet encoded therein, or a communication error is detected with the in-band pulse. Signal length detection counts the length of a received signal after the received signal exceeds a radar threshold. The count identifies the received signal length upon drop of the power. The signal is identified as a radar when the power drops before a PHY error occurs, or when the power drop occurs after a PHY error and a delay time equivalent to the shortest radar signal. A radar signal is also identified upon a timeout wait for a power drop after a PHY error.Type: ApplicationFiled: April 2, 2003Publication date: November 6, 2003Inventors: Paul Husted, William J. McFarland, Xiaoru Zhang, John Thomson