Patents by Inventor Guanghan Xu
Guanghan Xu 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: 8437788Abstract: Disclosed are method and apparatus for allocating radio resources. The method for allocating radio resource includes: determining, by a base station, a group of downlink sub-channels and transmission parameters related to the group of downlink sub-channels according to downlink channel characteristics and downlink interference characteristics of each resource block and a downlink bandwidth requirement of a terminal reported by the terminal, and transmitting the group of downlink sub-channels and the related transmission parameters determined to the terminal. The method and apparatus are able to allocate radio resources and determine transmission parameters based on user service requirement and system channel conditions, which greatly optimizes the system performances and improves efficiency.Type: GrantFiled: October 9, 2008Date of Patent: May 7, 2013Assignee: Beijing Xinwei Telecom Technology Inc.Inventors: Hang Li, Qihua Huang, Guanghan Xu, Hui Zhou, Hui Fan
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Patent number: 8331269Abstract: Embodiments of the present invention provide a method and device for transmitting voice in a wireless system.Type: GrantFiled: October 9, 2008Date of Patent: December 11, 2012Assignee: Beijing Xinwei Telecom Technology Inc.Inventors: Hang Li, Guanghan Xu, Yongquan Qiang, Hui Zhou, Qiang Ma
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Patent number: 8320317Abstract: The present invention provides a ranging method and apparatus, a frame structure includes one or more downlink service time slots, a guard interval between downlink sub-frame and uplink sub-frame and one or more uplink service time slots, and the method includes calculating start time of the first uplink service time slot, configuring the start time as reference time; generating a ranging signal; subtract a sum of time period needed for sending the ranging signal and reference time delay from the reference time and configure obtained time result as time of starting to send the ranging signal; subtract the length of a special ranging time slot from the reference time and configure obtained time result as time of starting to receive the ranging signal by a BS; receiving and processing the ranging signal. By the method and apparatus, all kinds of interference are minimized and an optimum ranging function is implemented.Type: GrantFiled: September 27, 2008Date of Patent: November 27, 2012Assignee: Beijing Xinweu Telecom Technology Inc.Inventors: Jun Huang, Hang Li, Guanghan Xu
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Patent number: 8289914Abstract: Embodiments of the present invention provide a signal transmission method and apparatus used in an Orthogonal Frequency Division Multiple Access (OFDMA) wireless communication system, to enhance stability of signal transmission and resist time-frequency dispersion. The signal transmission method used in the OFDMA wireless communication system provided by an embodiment of the invention includes: converting an L×1 symbol vector into an N×1 modulating signal vector according to a loading factor fed back by a receiving party, in which value of N is known, both L and N are natural numbers larger than one, N is larger than or equal to L, the loading factor is a ratio of L and N; mapping the N×1 modulating signal vector into N time-frequency grids; and converting the N time-frequency grids into a signal waveform and sending the signal waveform to the receiving party.Type: GrantFiled: September 27, 2008Date of Patent: October 16, 2012Assignee: Beijing Xinwei Telecom Technology Inc.Inventors: Hang Li, Guanghan Xu
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Patent number: 8174960Abstract: A time division duplex wireless communication system based on Code Spreading-Orthogonal Frequency Division Multiple Access (CS-OFDMA) and a smart antenna includes: an antenna array and multichannel transceiver, a space processor, a demodulator, an L2 processor and a modulator. The CS-OFDMA system provided by the present invention combines synchronous CDMA technique and OFDMA technique, overcomes the severe ISI caused by spectrum-spreading by the conventional CDMA system while transmitting wideband data, effectively counteracts frequency-selective fading and inter-cell interference, and is beneficial to reliable transmission of narrowband voice and wideband data and also beneficial to co-frequency networking.Type: GrantFiled: October 8, 2008Date of Patent: May 8, 2012Assignee: Beijing Xinwei Telecom Technology, Inc.Inventors: Guanghan Xu, Hang Li, Jun Huang
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Patent number: 8086181Abstract: A method and system for interference reduction for telecommunication systems are disclosed. The system comprises a base station control device (BCD) for configuring one or more parameters for operating one or more base stations (BSs), a first BS covering a first cell having one or more mobile terminals therein, a second BS covering a second cell neighboring to the first cell and sharing a predetermined frequency band with the first cell, wherein one or more radio frames constructed for communications between the first BS and any mobile terminal of the first cell and one or more radio frames constructed for communications between the second BS and any mobile terminal of the second cell are distinguishable by defining different channel configuration sets having one or more operation parameters, wherein the parameters includes a training sequence, a spreading code, and a channel observation window position.Type: GrantFiled: December 7, 2010Date of Patent: December 27, 2011Assignee: Cisco Technology, Inc.Inventors: Daniel Wee, Hang Li, Weidong Yang, Guanghan Xu
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Publication number: 20110076954Abstract: A method and system for interference reduction for telecommunication systems are disclosed. The system comprises a base station control device (BCD) for configuring one or more parameters for operating one or more base stations (BSs), a first BS covering a first cell having one or more mobile terminals therein, a second BS covering a second cell neighboring to the first cell and sharing a predetermined frequency band with the first cell, wherein one or more radio frames constructed for communications between the first BS and any mobile terminal of the first cell and one or more radio frames constructed for communications between the second BS and any mobile terminal of the second cell are distinguishable by defining different channel configuration sets having one or more operation parameters, wherein the parameters includes a training sequence, a spreading code, and a channel observation window position.Type: ApplicationFiled: December 7, 2010Publication date: March 31, 2011Applicant: CISCO TECHNOLOGY, INC.Inventors: Daniel Wee, Hang Li, Weidong Yang, Guanghan Xu
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Patent number: 7885604Abstract: A method and system for interference reduction for telecommunication systems are disclosed. The system comprises a base station control device (BCD) for configuring one or more parameters for operating one or more base stations (BSs), a first BS covering a first cell having one or more mobile terminals therein, a second BS covering a second cell neighboring to the first cell and sharing a predetermined frequency band with the first cell, wherein one or more radio frames constructed for communications between the first BS and any mobile terminal of the first cell and one or more radio frames constructed for communications between the second BS and any mobile terminal of the second cell are distinguishable by defining different channel configuration sets having one or more operation parameters, wherein the parameters includes a training sequence, a spreading code, and a channel observation window position.Type: GrantFiled: May 18, 2006Date of Patent: February 8, 2011Assignee: Cisco Technology, Inc.Inventors: Daniel Wee, Hang Li, Weidong Yang, Guanghan Xu
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Publication number: 20100311452Abstract: Disclosed are method and apparatus for allocating radio resources. The method for allocating radio resource includes: determining, by a base station, a group of downlink sub-channels and transmission parameters related to the group of downlink sub-channels according to downlink channel characteristics and downlink interference characteristics of each resource block and a downlink bandwidth requirement of a terminal reported by the terminal, and transmitting the group of downlink sub-channels and the related transmission parameters determined to the terminal. The method and apparatus are able to allocate radio resources and determine transmission parameters based on user service requirement and system channel conditions, which greatly optimizes the system performances and improves efficiency.Type: ApplicationFiled: October 9, 2008Publication date: December 9, 2010Inventors: Hang Li, Qihua Huang, Guanghan Xu, Hui Zhou, Hui Fan
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Publication number: 20100238846Abstract: A time division duplex wireless communication system based on Code Spreading-Orthogonal Frequency Division Multiple Access (CS-OFDMA) and a smart antenna includes: an antenna array and multichannel transceiver, a space processor, a demodulator, an L2 processor and a modulator. The CS-OFDMA system provided by the present invention combines synchronous CDMA technique and OFDMA technique, overcomes the severe ISI caused by spectrum-spreading by the conventional CDMA system while transmitting wideband data, effectively counteracts frequency-selective fading and inter-cell interference, and is beneficial to reliable transmission of narrowband voice and wideband data and also beneficial to co-frequency networking.Type: ApplicationFiled: October 8, 2008Publication date: September 23, 2010Applicant: BEIJING XINWEI TELECOM TECHNOLOGY INC.Inventors: Guanghan Xu, Hang Li, Jun Huang
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Publication number: 20100220694Abstract: The present invention provides a ranging method and apparatus, a frame structure includes one or more downlink service time slots, a guard interval between downlink sub-frame and uplink sub-frame and one or more uplink service time slots, and the method includes calculating start time of the first uplink service time slot, configuring the start time as reference time; generating a ranging signal; subtract a sum of time period needed for sending the ranging signal and reference time delay from the reference time and configure obtained time result as time of starting to send the ranging signal; subtract the length of a special ranging time slot from the reference time and configure obtained time result as time of starting to receive the ranging signal by a BS; receiving and processing the ranging signal. By the method and apparatus, all kinds of interference are minimized and an optimum ranging function is implemented.Type: ApplicationFiled: September 27, 2008Publication date: September 2, 2010Applicant: BEIJING XINWEI TELECOM TECHNOLOGY INC.Inventors: Jun Huang, Hang Li, Guanghan Xu
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Publication number: 20100220677Abstract: Embodiments of the present invention provide a method and device for transmitting voice in a wireless system.Type: ApplicationFiled: October 9, 2008Publication date: September 2, 2010Inventors: Hang Li, Guanghan Xu, Yongquan Qiang, Hui Zhou, Qiang Ma
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Publication number: 20100208676Abstract: Embodiments of the present invention provide a signal transmission method and apparatus used in an Orthogonal Frequency Division Multiple Access (OFDMA) wireless communication system, to enhance stability of signal transmission and resist time-frequency dispersion. The signal transmission method used in the OFDMA wireless communication system provided by an embodiment of the invention includes: converting an L×1 symbol vector into an N×1 modulating signal vector according to a loading factor fed back by a receiving party, in which value of N is known, both L and N are natural numbers larger than one, N is larger than or equal to L, the loading factor is a ratio of L and N; mapping the N×1 modulating signal vector into N time-frequency grids; and converting the N time-frequency grids into a signal waveform and sending the signal waveform to the receiving party.Type: ApplicationFiled: September 27, 2008Publication date: August 19, 2010Applicant: BEIJING XINWEI TELECOM TECHNOLOGY INC.Inventors: Hang Li, Guanghan Xu
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Patent number: 7656936Abstract: A method and system for reducing interference in a wireless communication network is disclosed. The wireless communication network has at least one base station using an antenna array and one or more code channels to receive or transmit one or more communication signals from or to a plurality of terminals used by one or more users. A signal received by the antenna array carries one or more training sequences and a traffic signal in a frame. After estimating a spatial signature and joint channel response model per user based on the training sequences, one or more spatial weights are found based on the estimated spatial signature and joint channel response model to maximize a signal to noise ratio. A joint detection matrix is then formed based on the estimated spatial weights, the joint channel response model, and a user code channel assignment.Type: GrantFiled: January 28, 2003Date of Patent: February 2, 2010Assignee: Cisco Technology, Inc.Inventors: Hang Li, Weidong Yang, Guanghan Xu
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Publication number: 20080160921Abstract: A method and system for mitigating interference in a communication system, comprising at least one base station and at least one terminal, are disclosed. The base stations and terminals communicate through a channel existing between them, and the channels include at least a first signal channel and a second signal channel. The method includes determination of channel, noise and self-interference characteristic, computation of a rate limit of the channels, computation of the rate assignment of the channels, and assignment of the computed rate assignments to the channels. In another aspect of the present invention, the method includes determination of channel characteristics; computation of a power control margin, self-interference characteristics, power control command; and assignment of the computed power control command to each communicating terminal and base station.Type: ApplicationFiled: March 13, 2008Publication date: July 3, 2008Applicant: CISCO TECHNOLOGY INC.Inventors: Hang Li, Guanghan Xu
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Patent number: 7349504Abstract: A method and system for mitigating interference in a communication system, comprising at least one base station and at least one terminal, are disclosed. The base stations and terminals communicate through a channel existing between them, and the channels include at least a first signal channel and a second signal channel. The method includes determination of channel, noise and self-interference characteristic, computation of a rate limit of the channels, computation of the rate assignment of the channels, and assignment of the computed rate assignments to the channels. In another aspect of the present invention, the method includes determination of channel characteristics; computation of a power control margin, self-interference characteristics, power control command; and assignment of the computed power control command to each communicating terminal and base station.Type: GrantFiled: March 18, 2005Date of Patent: March 25, 2008Assignee: Navini Networks, Inc.Inventors: Hang Li, Guanghan Xu
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Publication number: 20070010203Abstract: A method and system for interference reduction for telecommunication systems are disclosed. The system comprises a base station control device (BCD) for configuring one or more parameters for operating one or more base stations (BSs), a first BS covering a first cell having one or more mobile terminals therein, a second BS covering a second cell neighboring to the first cell and sharing a predetermined frequency band with the first cell, wherein one or more radio frames constructed for communications between the first BS and any mobile terminal of the first cell and one or more radio frames constructed for communications between the second BS and any mobile terminal of the second cell are distinguishable by defining different channel configuration sets having one or more operation parameters, wherein the parameters includes a training sequence, a spreading code, and a channel observation window position.Type: ApplicationFiled: May 18, 2006Publication date: January 11, 2007Inventors: Daniel Wee, Hang Li, Weidong Yang, Guanghan Xu
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Publication number: 20060293060Abstract: A method and system is disclosed for load balancing in a wireless communication system. The method has two major processes for load balancing purpose: the first process moves a mobile terminal from its host base station to some less loaded base station after the expiration of a switch time interval determined by the signal strength difference between the original host base station and the base station that the mobile terminal is moving to; the second process moves the mobile terminal from its host base station to the base station with the strongest signal strength periodically.Type: ApplicationFiled: October 5, 2005Publication date: December 28, 2006Inventors: Weidong Yang, John Grabner, Guanghan Xu, Hang Jin, Hang Li
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Patent number: 7151755Abstract: A method and system for multi-cell interference reduction in a wireless communication system is disclosed. The present disclosure describes a new method and system for accurately detecting the characteristics of the interfering signals from relevant sources such as neighboring co-channel cells and other persistent interference sources. In order to better estimate the interfering signals, a base station designates a small inactive window in the transmit frame for a cell during which the communications between the base station and its terminals are reduced while every other communication pursues. As such, the interfering signals can be well exposed and the characteristics can be accurately detected. Based on the detected characteristics of the interfering signals, the base station can specifically design beam forming mechanism or other means to cancel or minimize the impact of such interference during regular communications.Type: GrantFiled: August 23, 2002Date of Patent: December 19, 2006Assignee: Navini Networks, Inc.Inventor: Guanghan Xu
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Publication number: 20060210001Abstract: A method and system for mitigating interference in a communication system, comprising at least one base station and at least one terminal, are disclosed. The base stations and terminals communicate through a channel existing between them, and the channels include at least a first signal channel and a second signal channel. The method includes determination of channel, noise and self-interference characteristic, computation of a rate limit of the channels, computation of the rate assignment of the channels, and assignment of the computed rate assignments to the channels. In another aspect of the present invention, the method includes determination of channel characteristics; computation of a power control margin, self-interference characteristics, power control command; and assignment of the computed power control command to each communicating terminal and base station.Type: ApplicationFiled: March 18, 2005Publication date: September 21, 2006Applicant: Navini Networks Inc.Inventors: Hang Li, Guanghan Xu