Patents by Inventor Shiau-He Shawn Tsai

Shiau-He Shawn Tsai 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: 7522919
    Abstract: Noise is measured at one or more base stations in a mobile communication system during periodic silence periods. A periodic silence period is defined for at least one carrier that is independent of reverse link channel frame boundaries. The radio base stations transmits silence parameters defining the periodic silence period to mobile stations, which stop transmitting during the periodic silence periods. A time reference is provided to the mobile stations to synchronize the silence periods for all mobile stations.
    Type: Grant
    Filed: February 27, 2004
    Date of Patent: April 21, 2009
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Young C. Yoon, Wanshi Chen, Hsien Woo, Anthony C. K. Soong, Srinivasan Balasubramanian, Thawatt Gopal, Long Duan, Shiau-He Shawn Tsai
  • Patent number: 7519019
    Abstract: A radio base station performs reverse link rate control in a wireless communication network by “stealing” bits on a forward common power control channel. The forward common power control channel is divided into a plurality of frames, with each frame including a plurality of power control groups and each power control group including a plurality of power control slots. The radio base station may dynamically select power control slots depending on user demand to be used for reverse link rate control.
    Type: Grant
    Filed: March 15, 2004
    Date of Patent: April 14, 2009
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Young C. Yoon, Srinivasan Balasubramanian, David Reeves Comstock, Long L. Duan, Ralph Gholmieh, Thawatt Gopal, Patrick A. Hosein, Anthony C. K. Soong, Shiau-He Shawn Tsai, Rath Vannithamby, Jonas Wiorek
  • Patent number: 7469146
    Abstract: A wireless communication network receives packet data transmissions from a mobile station, tracks the occurrence of retransmission requests sent to the mobile station responsive thereto, and modifies the radio link assignments for the mobile station based at least in part on said tracking. For example, a base station controller may be configured to manage the active set of a mobile station based on the number and/or frequency of NACK messages sent by the radio base stations in the mobile station's active set(s) responsive to packet data transmissions from the mobile station. The ACK/NACK response of a radio base station to mobile station transmissions may be used to detect link imbalance, identify poor reverse link channels, etc. The base station controller can add or change radio links based on the ACK/NACK response to improve reverse link performance, trigger voice call handoff, correct link imbalance, etc.
    Type: Grant
    Filed: July 12, 2004
    Date of Patent: December 23, 2008
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Anthony C. K. Soong, Tao Wu, Thawatt Gopal, Young C. Yoon, Shiau-He Shawn Tsai
  • Patent number: 7466666
    Abstract: A base station receives data frames from a mobile station and selectively gates a physical layer radio channel to provide ACK and NACK indications responsive to the receipt of the data frames from the mobile station. The physical layer radio channel is gated on to provide one of an ACK and a NACK indication to the mobile station, and is gated off to provide the other one of the ACK and NACK indications to the mobile station.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: December 16, 2008
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Young C. Yoon, Shiau-He Shawn Tsai, Anthony C. K. Soong
  • Patent number: 7406077
    Abstract: An apparatus and method provide MAC logic enabling the use of two or more reverse link rate controls at the same time in one or more sectors of a radio base station. That enables the base station to control reverse link loading via reverse link rate control, while assigning mobile stations to the type of reverse link rate control best suited to their needs. For example, the base station MAC logic may implement both a common rate controller that generates per-sector rate control commands, and a dedicated rate controller that generates per-user rate control commands and assign mobile stations having relatively lax reverse link service needs to the common rate controller, while assigning mobile stations having more demanding reverse link service requirements to the dedicated rate control. More than two rate controls can be implemented, and exemplary choices include per-user, per-sector, per-group, and scheduled rate control in any combination.
    Type: Grant
    Filed: January 9, 2004
    Date of Patent: July 29, 2008
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Srinivasan Balasubramanian, David Reeves Comstock, Long L. Duan, Ralph Gholmieh, Thawatt Gopal, Patrick Ahamad Hosein, Seong-Jun Oh, Anthony C. K. Soong, Shiau-He Shawn Tsai, Rath Vannithamby, Jonas Wiorek, Hsein Woo, Tao Wu, Young C. Yoon
  • Patent number: 7346314
    Abstract: A method and apparatus to provide a deterministic power control mechanism for the transmission of mobile station power control commands based on transmitting non-power control commands for which mobile stations exhibit deterministic, observable responses at related transmit powers, e.g., at the same power. For example, a wireless network base station may adjust the target used for sending power control commands to a given mobile station by observing whether that mobile station correctly responds to rate control or retransmit control commands sent at the same transmit power. The mobile station's response (or non-response) to such non-power control commands is readily observable and can be taken as an indication of whether the power target is sufficient for current radio conditions. Although not so limited, this approach may be particularly beneficial where non-power control commands are sent along with the power commands on a sub-channel of a common power control channel.
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: March 18, 2008
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Shiau-He Shawn Tsai, Anthony C. K. Soong, Young C. Yoon
  • Patent number: 7313167
    Abstract: An improved approach to noise estimation permits, for example, tighter closed-loop power control in a wireless communication network with attendant improvements in transmit power efficiency and network capacity. In an exemplary embodiment, the received signal-to-noise ratio (SNR) of a data signal is estimated based on noise samples obtained from one or more other signals received in association with the data signal. In general, these associated signals are characterized by the receiver's ability to extract like valued samples from them, such that pairs of these like valued signal samples may be subtracted, thereby canceling their deterministic signal components and leaving only difference values representative of the non-deterministic noise components of the signal samples.
    Type: Grant
    Filed: September 30, 2002
    Date of Patent: December 25, 2007
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Young C. Yoon, Shiau-He Shawn Tsai
  • Patent number: 7299402
    Abstract: A method of reverse link power control for a reverse packet data channel in a wireless communication system allows a mobile station to autonomously change its data transmission rate. The mobile station transmits packet data over a reverse packet data channel having a data rate variant transmit power level that varies based on a transmit data rate on the packet data channel. The mobile station further transmits control signals over a reverse control channel associated with the reverse packet data channel. The transmit power level of the reverse control channel is such that the transmit power level does not vary with the transmit data rate on the packet data channel. The radio base station measures the strength of the received signals on the reverse control channel, compares the measured strength to a power control set point, and generates a power control signal responsive to the comparison of the control signal to the power control set point.
    Type: Grant
    Filed: February 13, 2004
    Date of Patent: November 20, 2007
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Anthony C. K. Soong, Seong-Jun Oh, Shiau-He Shawn Tsai, Young C. Yoon
  • Patent number: 7231183
    Abstract: A method and a receiver for determining the quality of a wireless communications link are described. The link quality is determined on the basis of an encoded signal that is transmitted via the communications link and that includes at least two signal portions experiencing different states of one or more transmission channels. The method comprises the steps of providing individual channel quality values for the different channels and determining a quality measure indicative of the link quality by averaging the individual channel quality values in the exponential domain.
    Type: Grant
    Filed: October 9, 2003
    Date of Patent: June 12, 2007
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Mathias Pauli, Udo Wachsmann, Shiau-He (Shawn) Tsai
  • Patent number: 7142865
    Abstract: A wireless receiver, such as in a mobile station or base station within a wireless communication network, estimates the frame error rate (FER) for one channel using signal information received on another, associated channel. As such, FER estimates may be generated for a channel of interest during discontinuous periods of that channel, or where the duty cycle of the channel is too low to support a desired FER estimation rate. Signal information received on the associated channel is manipulated as needed to conform to the format of the channel of interest, such as the encoding format, and then decoded as if it had been received on the channel of interest. Thus, the signal information is treated as virtually encoded data for the channel of interest, and may comprise essentially any type of signal that is known or determinable, such as a pilot, synchronization, traffic, or control channel.
    Type: Grant
    Filed: May 31, 2002
    Date of Patent: November 28, 2006
    Assignee: Telefonaktie Bolaget LM Ericsson (publ)
    Inventors: Shiau-He Shawn Tsai, Farideh Khaleghi, Patrik Nils Lundqvist
  • Publication number: 20050181834
    Abstract: A base station generates per-cell ACK/NACK responses rather than per-sector ACK/NACK responses. For a given mobile station signal received in softer handoff at two of the base station's sectors, the base station generates an ACK response if at least one of the soft handoff sectors correctly receives the signal, and otherwise generates a NACK response. Alternatively, the base station can combine the softer handoff signals and generate ACK/NACK responses based on whether the combined signal is correctly received. Since only one set of ACK/NACK responses are generated for all of the softer handoff sectors, the base station can use the forward link in just one softer handoff sector to send the ACK/NACK responses to the mobile station, consuming fewer forward link transmit resources at the base station. Or, the base station can send the same ACK/NACK responses from two or more softer handoff sectors, thus allowing diversity combining of the ACK/NACK responses at the mobile station.
    Type: Application
    Filed: December 20, 2004
    Publication date: August 18, 2005
    Inventors: Wanshi Chen, Rath Vannithamby, Shiau-He Shawn Tsai, Young Yoon, Anthony Soong, Tao Wu
  • Publication number: 20040258096
    Abstract: A base station receives data frames from a mobile station and selectively gates a physical layer radio channel to provide ACK and NACK indications responsive to the receipt of the data frames from the mobile station. The physical layer radio channel is gated on to provide one of an ACK and a NACK indication to the mobile station, and is gated off to provide the other one of the ACK and NACK indications to the mobile station.
    Type: Application
    Filed: January 30, 2004
    Publication date: December 23, 2004
    Inventors: Young C. Yoon, Shiau-He Shawn Tsai, Anthony C.K. Soong
  • Publication number: 20040219883
    Abstract: A method and a receiver for determining the quality of a wireless communications link are described. The link quality is determined on the basis of an encoded signal that is transmitted via the communications link and that includes at least two signal portions experiencing different states of one or more transmission channels. The method comprises the steps of providing individual channel quality values for the different channels and determining a quality measure indicative of the link quality by averaging the individual channel quality values in the exponential domain.
    Type: Application
    Filed: October 9, 2003
    Publication date: November 4, 2004
    Inventors: Mathias Pauli, Udo Wachsmann, Shiau-He (Shawn) Tsai
  • Publication number: 20040203397
    Abstract: An improved approach to noise estimation permits, for example, tighter closed-loop power control in a wireless communication network with attendant improvements in transmit power efficiency and network capacity. In an exemplary embodiment, the received signal-to-noise ratio (SNR) of a data signal is estimated based on noise samples obtained from one or more other signals received in association with the data signal. In general, these associated signals are characterized by the receiver's ability to extract like valued samples from them, such that pairs of these like valued signal samples may be subtracted, thereby canceling their deterministic signal components and leaving only difference values representative of the non-deterministic noise components of the signal samples.
    Type: Application
    Filed: September 30, 2002
    Publication date: October 14, 2004
    Inventors: Young C. Yoon, Shiau-He Shawn Tsai
  • Publication number: 20040193971
    Abstract: A method of reverse link power control for a reverse packet data channel in a wireless communication system allows a mobile station to autonomously change its data transmission rate. The mobile station transmits packet data over a reverse packet data channel having a data rate variant transmit power level that varies based on a transmit data rate on the packet data channel. The mobile station further transmits control signals over a reverse control channel associated with the reverse packet data channel. The transmit power level of the reverse control channel is such that the transmit power level does not vary with the transmit data rate on the packet data channel. The radio base station measures the strength of the received signals on the reverse control channel, compares the measured strength to a power control set point, and generates a power control signal responsive to the comparison of the control signal to the power control set point.
    Type: Application
    Filed: February 13, 2004
    Publication date: September 30, 2004
    Inventors: Anthony C.K. Soong, Seong-Jun Oh, Shiau-He Shawn Tsai, Young C. Yoon
  • Publication number: 20040179525
    Abstract: An apparatus and method provide MAC logic enabling the use of two or more reverse link rate controls at the same time in one or more sectors of a radio base station. That enables the base station to control reverse link loading via reverse link rate control, while assigning mobile stations to the type of reverse link rate control best suited to their needs. For example, the base station MAC logic may implement both a common rate controller that generates per-sector rate control commands, and a dedicated rate controller that generates per-user rate control commands and assign mobile stations having relatively lax reverse link service needs to the common rate controller, while assigning mobile stations having more demanding reverse link service requirements to the dedicated rate control. More than two rate controls can be implemented, and exemplary choices include per-user, per-sector, per-group, and scheduled rate control in any combination.
    Type: Application
    Filed: January 9, 2004
    Publication date: September 16, 2004
    Inventors: Srinivasan Balasubramanian, David Reeves Comstock, Long L. Duan, Ralph Gholmieh, Thawatt Gopal, Patrick Ahamad Hosein, Seong-Jun Oh, Anthony C.K. Soong, Shiau-He Shawn Tsai, Rath Vannithamby, Jonas L. Wiorek, Hsien Woo, Tao Wu, Young C. Yoon
  • Publication number: 20030224836
    Abstract: A wireless receiver, such as in a mobile station or base station within a wireless communication network, estimates the frame error rate (FER) for one channel using signal information received on another, associated channel. As such, FER estimates may be generated for a channel of interest during discontinuous periods of that channel, or where the duty cycle of the channel is too low to support a desired FER estimation rate. Signal information received on the associated channel is manipulated as needed to conform to the format of the channel of interest, such as the encoding format, and then decoded as if it had been received on the channel of interest. Thus, the signal information is treated as virtually encoded data for the channel of interest, and may comprise essentially any type of signal that is known or determinable, such as a pilot, synchronization, traffic, or control channel.
    Type: Application
    Filed: May 31, 2002
    Publication date: December 4, 2003
    Inventors: Shiau-He Shawn Tsai, Farideh Khaleghi, Patrik Nils Lundqvist
  • Publication number: 20030223396
    Abstract: A mobile terminal for CDMA systems has multiple operating states including an active state and a control hold state. In the active state the mobile terminal transmits an pilot signal on a pilot channel and rate control information on a reverse rate control channel. In the active state a sector selection code is applied to the reverse rate control channel to indicate selection of a serving base station for forward link communications. In the control hold state, the mobile terminal transmits a pilot signal covered by a sector selection code. The pilot signal may be gated, i.e., transmitted at a reduced duty cycle, in the control hold mode. The pilot signal may be transmitted on either the reverse pilot channel or the reverse rate control channel. Transmission on the other channel is suspended in the control hold state.
    Type: Application
    Filed: May 31, 2002
    Publication date: December 4, 2003
    Inventors: Shiau-He Shawn Tsai, Seong-Jun Oh, Patrik Nils Lundqvist