Patents by Inventor Liuqing Yang

Liuqing Yang 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).

  • Patent number: 8627401
    Abstract: Embodiments of a white space identifier are provided. According to one embodiment, the active channel information of a cable TV can be obtained through receiving and decoding a channel changing operation command from a remote control. The active channel information can then be transmitted to white space devices located within an interference range using a wireless transmitter. The wireless transmitter can be set to utilize a narrow fixed bandwidth.
    Type: Grant
    Filed: April 2, 2010
    Date of Patent: January 7, 2014
    Assignee: University of Florida Research Foundation, Incorporated
    Inventor: Liuqing Yang
  • Publication number: 20120017256
    Abstract: Embodiments of a white space identifier are provided. According to one embodiment, the active channel information of a cable TV can be obtained through receiving and decoding a channel changing operation command from a remote control. The active channel information can then be transmitted to white space devices located within an interference range using a wireless transmitter. The wireless transmitter can be set to utilize a narrow fixed bandwidth.
    Type: Application
    Filed: April 2, 2010
    Publication date: January 19, 2012
    Inventor: Liuqing Yang
  • Patent number: 7769115
    Abstract: Techniques are described that provide noncoherent demodulation via correlating “dirty” templates in wireless communication systems. In particular, the described techniques cross-correlate dirty templates that are adjacent symbol-long segments of the received noisy waveform. Unlike transmitted reference (TR) and differential templates that are noisy, i.e., propagate through the wireless communication channel, these dirty templates are both noisy and offset in time and, thus, are dirty. As a result, the described techniques enable noncoherent demodulation without timing synchronization and channel estimation. Symbol demodulation may be performed utilizing a maximum likelihood (ML) sequence detector or, alternatively, conditional ML demodulation may be performed to reduce receiver complexity. The described techniques may also be applied to a TR scheme to improve performance in the presence of mistiming.
    Type: Grant
    Filed: October 3, 2005
    Date of Patent: August 3, 2010
    Assignee: Regents of the University of Minnesota
    Inventors: Georgios B. Giannakis, Liuqing Yang
  • Patent number: 7738545
    Abstract: The invention provides an ultra-wideband (UWB) transmitter and various techniques for generating digitally filtered UWB pulses that substantially maximize power and bandwidth in one or more frequency bands while allowing narrow-band interference (NBI) to be avoided, e.g. interference to and from wireless local area networks (WLANs). In particular, the UWB transmitter utilizes a digital filter to generate digitally filtered UWB pulses to substantially maximize power and bandwidth in the Federal Communications Commission (FCC) spectral mask for UWB communications. In one embodiment, the invention provides a method comprising generating digitally filtered ultra-wide band (UWB) pulses to substantially maximize power in one or more frequency bands of a UWB spectrum and to substantially reduce power in one or more NBI frequency bands of the UWB spectrum. The invention may be implemented without modifying the analog components of existing UWB transmitters.
    Type: Grant
    Filed: September 29, 2004
    Date of Patent: June 15, 2010
    Assignee: Regents of the University of Minnesota
    Inventors: Georgios B. Giannakis, Liuqing Yang, Xiliang Luo
  • Patent number: 7561613
    Abstract: Techniques are described for generating digital carrier multi-band user codes for a baseband ultra-wideband (UWB) signal. The digital carrier multi-band user codes comprise spreading codes that enable multiple access in a UWB system. The user codes are digital, lead to baseband operation, and provide flexibility in handling narrow band interference (NBI) within the UWB system. In one embodiment, the invention provides a method comprising generating digital carrier multi-band user codes for a baseband ultra-wideband (UWB) signal of a user in an UWB system.
    Type: Grant
    Filed: September 29, 2004
    Date of Patent: July 14, 2009
    Assignee: Regents of the University of Minnesota
    Inventors: Georgios B. Giannakis, Liuqing Yang
  • Patent number: 7496128
    Abstract: Techniques are described for maintaining the orthogonality of waveforms transmitted in ultra wideband (UWB) multi-user wireless communication systems. The multi-stage block-spreading (MS-BS) techniques described herein deterministically eliminate multiple user interference (MUI) in the presence of frequency-selective fading channels. A transmitter includes a block-spreading unit to generate a stream of frames from a block of information bearing symbols by applying an orthogonal set of spreading codes, such as direct sequence cod& division multiple access (CDMA) codes or digital carrier frequency multiple access codes, such that the frames corresponding to different blocks of the symbols are interleaved. The transmitter further includes a time-hopping spreading unit to generate a stream of chips from the stream of frames by applying an orthogonal set of time-hopping (TH) spreading codes such that chips corresponding to different frames are interleaved.
    Type: Grant
    Filed: March 8, 2004
    Date of Patent: February 24, 2009
    Assignee: Regents of the University of Minnesota
    Inventors: Georgios B. Giannakis, Liuqing Yang
  • Patent number: 7342972
    Abstract: Techniques are described for synchronizing the timing of the receiver with the received waveform in ultra wideband (UWB) communication systems. The described techniques correlate the received waveform with dirty templates, i.e. segments of the received waveform, with the received waveform to estimate the timing offset. The described techniques include receiving an ultra wideband (UWB) waveform through a wireless communication channel, wherein the received UWB waveform comprises bursts of information-bearing symbols. A template is selected to be used for estimating the timing offset of a burst of the received UWB waveform, wherein the template comprises a segment of a burst of the received UWB waveform, and the template is correlated with a segment of a burst of the received waveform so as to form an estimate of the timing offset of the received UWB waveform. A stream of symbol estimates is output in accordance with the estimated timing offset.
    Type: Grant
    Filed: March 8, 2004
    Date of Patent: March 11, 2008
    Assignee: Regents of the University of Minnesota
    Inventors: Georgios B. Giannakis, Liuqing Yang
  • Patent number: 7340009
    Abstract: Space-time (ST) coding techniques are described for multi-antenna transmissions in ultra-wideband (UWB) communication systems. The ST coding schemes may, therefore, be tailored for dense multipath channels. The techniques may be applied with linear and nonlinear modulation, coherent and noncoherent reception, and block interleaving of symbols. An UWB communication system is described that includes an ST encoder at the transmitter, multiple transmit and receive antennas, and two-step maximum ratio combining (MRC) at the receiver. The two-step MRC enables the receiver to collect full spatial and multipath diversity from a transmission. Two coding schemes for an UWB system with two transmit antennas and one receive antenna are described. Multiple antenna transmissions of ST encoded symbols increase the amount of diversity a receiver is able to collect without increasing the complexity of the receiver.
    Type: Grant
    Filed: March 8, 2004
    Date of Patent: March 4, 2008
    Assignee: Regents of the University of Minnesota
    Inventors: Georgios B. Giannakis, Liuqing Yang
  • Publication number: 20060083338
    Abstract: Techniques are described that provide noncoherent demodulation via correlating “dirty” templates in wireless communication systems. In particular, the described techniques cross-correlate dirty templates that are adjacent symbol-long segments of the received noisy waveform. Unlike transmitted reference (TR) and differential templates that are noisy, i.e., propagate through the wireless communication channel, these dirty templates are both noisy and offset in time and, thus, are dirty. As a result, the described techniques enable noncoherent demodulation without timing synchronization and channel estimation. Symbol demodulation may be performed utilizing a maximum likelihood (ML) sequence detector or, alternatively, conditional ML demodulation may be performed to reduce receiver complexity. The described techniques may also be applied to a TR scheme to improve performance in the presence of mistiming.
    Type: Application
    Filed: October 3, 2005
    Publication date: April 20, 2006
    Applicant: Regents of the University of Minnesota
    Inventors: Georgios Giannakis, Liuqing Yang
  • Publication number: 20050105594
    Abstract: The invention provides an ultra-wideband (UWB) transmitter and various techniques for generating digitally filtered UWB pulses that substantially maximize power and bandwidth in one or more frequency bands while allowing narrow-band interference (NBI) to be avoided, e.g. interference to and from wireless local area networks (WLANs). In particular, the UWB transmitter utilizes a digital filter to generate digitally filtered UWB pulses to substantially maximize power and bandwidth in the Federal Communications Commission (FCC) spectral mask for UWB communications. In one embodiment, the invention provides a method comprising generating digitally filtered ultra-wide band (UWB) pulses to substantially maximize power in one or more frequency bands of a UWB spectrum and to substantially reduce power in one or more NBI frequency bands of the UWB spectrum. The invention may be implemented without modifying the analog components of existing UWB transmitters.
    Type: Application
    Filed: September 29, 2004
    Publication date: May 19, 2005
    Inventors: Georgios Giannakis, Liuqing Yang, Xiliang Luo
  • Publication number: 20050105588
    Abstract: Techniques are described for generating digital carrier multi-band user codes for a baseband ultra-wideband (UWB) signal. The digital carrier multi-band user codes comprise spreading codes that enable multiple access in a UWB system. The user codes are digital, lead to baseband operation, and provide flexibility in handling narrow band interference (NBI) within the UWB system. In one embodiment, the invention provides a method comprising generating digital carrier multi-band user codes for a baseband ultra-wideband (UWB) signal of a user in an UWB system.
    Type: Application
    Filed: September 29, 2004
    Publication date: May 19, 2005
    Inventors: Georgios Giannakis, Liuqing Yang
  • Publication number: 20040240527
    Abstract: Techniques are described for maintaining the orthogonality of waveforms transmitted in ultra wideband (UWB) multi-user wireless communication systems. The multi-stage block-spreading (MS-BS) techniques described herein deterministically eliminate multiple user interference (MUI) in the presence of frequency-selective fading channels. A transmitter includes a block-spreading unit to generate a stream of frames from a block of information bearing symbols by applying an orthogonal set of spreading codes, such as direct sequence code-division multiple access (CDMA) codes or digital carrier frequency multiple access codes, such that the frames corresponding to different blocks of the symbols are interleaved. The transmitter further includes a time-hopping spreading unit to generate a stream of chips from the stream of frames by applying an orthogonal set of time-hopping (TH) spreading codes such that chips corresponding to different frames are interleaved.
    Type: Application
    Filed: March 8, 2004
    Publication date: December 2, 2004
    Inventors: Georgios B. Giannakis, Liuqing Yang
  • Publication number: 20040202256
    Abstract: Space-time (ST) coding techniques are described for multi-antenna transmissions in ultra-wideband (UWB) communication systems. The ST coding schemes may, therefore, be tailored for dense multipath channels. The techniques may be applied with linear and nonlinear modulation, coherent and noncoherent reception, and block interleaving of symbols. An UWB communication system is described that includes an ST encoder at the transmitter, multiple transmit and receive antennas, and two-step maximum ratio combining (MRC) at the receiver. The two-step MRC enables the receiver to collect full spatial and multipath diversity from a transmission. Two coding schemes for an UWB system with two transmit antennas and one receive antenna are described. Multiple antenna transmissions of ST encoded symbols increase the amount of diversity a receiver is able to collect without increasing the complexity of the receiver.
    Type: Application
    Filed: March 8, 2004
    Publication date: October 14, 2004
    Inventors: Georgios B. Giannakis, Liuqing Yang