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: 7522919Abstract: 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: GrantFiled: February 27, 2004Date of Patent: April 21, 2009Assignee: 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: 7519019Abstract: 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: GrantFiled: March 15, 2004Date of Patent: April 14, 2009Assignee: 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: 7469146Abstract: 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: GrantFiled: July 12, 2004Date of Patent: December 23, 2008Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Anthony C. K. Soong, Tao Wu, Thawatt Gopal, Young C. Yoon, Shiau-He Shawn Tsai
-
Patent number: 7466666Abstract: 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: GrantFiled: January 30, 2004Date of Patent: December 16, 2008Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Young C. Yoon, Shiau-He Shawn Tsai, Anthony C. K. Soong
-
Patent number: 7406077Abstract: 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: GrantFiled: January 9, 2004Date of Patent: July 29, 2008Assignee: 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: 7346314Abstract: 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: GrantFiled: January 30, 2004Date of Patent: March 18, 2008Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Shiau-He Shawn Tsai, Anthony C. K. Soong, Young C. Yoon
-
Patent number: 7313167Abstract: 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: GrantFiled: September 30, 2002Date of Patent: December 25, 2007Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Young C. Yoon, Shiau-He Shawn Tsai
-
Patent number: 7299402Abstract: 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: GrantFiled: February 13, 2004Date of Patent: November 20, 2007Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Anthony C. K. Soong, Seong-Jun Oh, Shiau-He Shawn Tsai, Young C. Yoon
-
Patent number: 7231183Abstract: 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: GrantFiled: October 9, 2003Date of Patent: June 12, 2007Assignee: Telefonaktiebolaget LM Ericsson (publ)Inventors: Mathias Pauli, Udo Wachsmann, Shiau-He (Shawn) Tsai
-
Patent number: 7142865Abstract: 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: GrantFiled: May 31, 2002Date of Patent: November 28, 2006Assignee: Telefonaktie Bolaget LM Ericsson (publ)Inventors: Shiau-He Shawn Tsai, Farideh Khaleghi, Patrik Nils Lundqvist
-
Publication number: 20050181834Abstract: 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: ApplicationFiled: December 20, 2004Publication date: August 18, 2005Inventors: Wanshi Chen, Rath Vannithamby, Shiau-He Shawn Tsai, Young Yoon, Anthony Soong, Tao Wu
-
Publication number: 20040258096Abstract: 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: ApplicationFiled: January 30, 2004Publication date: December 23, 2004Inventors: Young C. Yoon, Shiau-He Shawn Tsai, Anthony C.K. Soong
-
Publication number: 20040219883Abstract: 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: ApplicationFiled: October 9, 2003Publication date: November 4, 2004Inventors: Mathias Pauli, Udo Wachsmann, Shiau-He (Shawn) Tsai
-
Publication number: 20040203397Abstract: 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: ApplicationFiled: September 30, 2002Publication date: October 14, 2004Inventors: Young C. Yoon, Shiau-He Shawn Tsai
-
Publication number: 20040193971Abstract: 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: ApplicationFiled: February 13, 2004Publication date: September 30, 2004Inventors: Anthony C.K. Soong, Seong-Jun Oh, Shiau-He Shawn Tsai, Young C. Yoon
-
Publication number: 20040179525Abstract: 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: ApplicationFiled: January 9, 2004Publication date: September 16, 2004Inventors: 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: 20030224836Abstract: 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: ApplicationFiled: May 31, 2002Publication date: December 4, 2003Inventors: Shiau-He Shawn Tsai, Farideh Khaleghi, Patrik Nils Lundqvist
-
Publication number: 20030223396Abstract: 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: ApplicationFiled: May 31, 2002Publication date: December 4, 2003Inventors: Shiau-He Shawn Tsai, Seong-Jun Oh, Patrik Nils Lundqvist