Patents by Inventor Brian K. Butler
Brian K. Butler 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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Publication number: 20030021334Abstract: Techniques for canceling pilot interference in a wireless (e.g., CDMA) communication system. In one method, a received signal comprised of a number of signal instances, each including a pilot, is initially processed to provide data samples. Each signal instance's pilot interference may be estimated by despreading the data samples with a spreading sequence for the signal instance, channelizing the despread data to provide pilot symbols, filtering the pilot symbols to estimate the channel response of the signal instance, and multiplying the estimated channel response with the spreading sequence to provide the estimated pilot interference. The pilot interference estimates due to all interfering multipaths are combined to derive the total pilot interference, which is subtracted from the data samples to provide pilot-canceled data samples. These samples are then processed to derive demodulated data for each of at least one (desired) signal instance in the received signal.Type: ApplicationFiled: October 10, 2001Publication date: January 30, 2003Inventors: Jeffrey A. Levin, Thomas B. Wilborn, Brian K. Butler, Paul E. Bender
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Patent number: 6496706Abstract: The present invention is a novel and improved method and system for communicating a frame of information according to a discontinuous transmit format. In particular, the present invention describes a method of transmitting eighth rate speech or data frames employing transmit gating and energy scaling which simultaneously reduces the battery usage of a variable rate wireless communication device, increases the capacity of the reverse link and provides reliable communication of the eighth rate frames. In the present invention, four methods are presented for transmitting an eighth rate data frame in which half of the frame is gated out and the remaining data is transmitted at nominal transmission energy to accomplish the aforementioned goals. In addition, a power control system in which identifies forward link power control bits that .1have been gated out by the remote station and inhibits adjustment of the transmission energy in response to that identification is disclosed.Type: GrantFiled: July 23, 1999Date of Patent: December 17, 2002Assignee: Qualcomm IncorporatedInventors: Yu-Cheun Jou, Ahmed Saifuddin, Edward G. Tiedemann, Jr., Brian K. Butler
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Publication number: 20020150128Abstract: A composite signal has two components, each carrying a stream of information that may be digital. In one application of a method according to an embodiment of the invention, at least one of the components is delayed such that a time relation between the streams of information is altered. The components are transferred via a common signal path such that upon transfer, the original time relation between the streams of information may be restored.Type: ApplicationFiled: October 9, 2001Publication date: October 17, 2002Inventors: Mohammad J. Mohseni, Brian K. Butler, Deepu John, Haitao Zhang
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Publication number: 20020131479Abstract: Techniques for canceling pilot interference in a wireless (e.g., CDMA) communication system. A received signal typically includes a number of signal instances (i.e., multipaths). For each multipath desired to be processed, the other multipaths act as interference on the desired multipath. If the pilot is generated based on a known data pattern (e.g., all zeros) and covered with a known channelization code (e.g., a Walsh code of zero), then the pilot in an interfering multipath may be estimated as the spreading sequence at a time offset corresponding to the arrival time of that multipath. The pilot interference from each interference multipath may be estimated based on the spreading sequence for the interfering multipath and the despreading sequence for the desired multipath. The total pilot interference from a number of interfering multipaths may be subtracted from the data component in the desired multipath to provide pilot-canceled data having improved performance.Type: ApplicationFiled: September 27, 2001Publication date: September 19, 2002Inventors: Brian K. Butler, Haitao Zhang, Paul E. Bender, Yu-Cheun Jou
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Publication number: 20020131487Abstract: A system for digital filtering includes a set of logic gates, a state storage, and a multiplexer. The state storage includes two or more storage banks and may also include combinatorial logic and/or at least one lookup table. In one application, a filtering operation according to a finite-impulse-response filter coefficient vector is performed without runtime multiplications. Applications to symmetric and antisymmetric filter coefficient vectors are described, as well as applications to filter coefficient vectors of arbitrary odd or even length.Type: ApplicationFiled: October 31, 2001Publication date: September 19, 2002Inventors: Brian K. Butler, Deepu John, Haitao Zhang, Mohammad J. Mohseni
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Publication number: 20020126746Abstract: In an antenna diversity environment, the timing offset of the receiver's fingers are based on the timing offset of the received peaks of the base station transmit signals. In a system with non-negligible multipath spacing, the timing offset of the received peaks of the base station transmit signals are not necessarily at the same location. In one embodiment, the demodulating elements for the signal from each base station antenna use the same offset for demodulating and determining an error signal based on pilot signal sampling prior to the timing offset and subsequent to the timing offset. The error signals are averaged and used by a time tracking loop to track the incoming signal. In another embodiment, the demodulating elements for the signal from each base station antenna independently time track the signals with different timing offsets for each finger. The preferred embodiment depends on the method used by the base station to multiplex the data onto multiple transmit antennas.Type: ApplicationFiled: September 25, 2001Publication date: September 12, 2002Inventors: Roland Reinhard Rick, Parvathanathan Subrahmanya, Brian K. Butler, Shimman Patel, Thunyachate Ekvetchavit
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Publication number: 20020123358Abstract: A novel and improved method and system for paging a cellular telephone or other wireless terminal using two paging channels that reduces standby mode power consumption described. In one embodiment of the invention, a minimally encoded quick paging channel is established over which short, quick page messages are transmitted during one of a set of quick paging slots. The quick page message indicates that a communications request has been received, and that the receiving communication terminals should process a highly encoded full paging channel over which more detailed, full page messages are transmitted during the next full paging slot. A terminal monitors full paging channel only after a quick page message has been received on the quick paging channel.Type: ApplicationFiled: January 31, 2002Publication date: September 5, 2002Inventors: Brian K. Butler, Klein S. Gilhousen
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Publication number: 20020118728Abstract: A spreading system according to an embodiment of the invention spreads two data signals. The system produces a filtered signal that is based on one of the data signals and an output signal that is based on both of the data signals. In one example, a spreading system is used to perform QPSK spreading of two data signals, including separate processing of the two data signals, in a practical manner. Such separate control may include filtering and/or gain control.Type: ApplicationFiled: November 2, 2001Publication date: August 29, 2002Inventors: Mohammad J. Mohseni, Brian K. Butler, Deepu John, Haitao Zhang
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Patent number: 6421540Abstract: A quick paging system having a base station, a plurality of terminals, and a full paging channel having a plurality of slots for transmitting paging information to the terminals is described. A quick paging channel having a plurality of quick paging channel slots each corresponding to a full paging channel slot is provided wherein at least one indicator is positioned within a selected quick paging channel slot that instructs at least one selected terminal corresponding to the at least one indicator in the quick paging slot to monitor the corresponding full paging channel slot.Type: GrantFiled: February 19, 1999Date of Patent: July 16, 2002Assignee: Qualcomm IncorporatedInventors: Klein S. Gilhousen, Brian K. Butler, Paul E. Bender, Avneesh Agrawal
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Patent number: 6393295Abstract: A novel and improved method and system for paging a cellular telephone or other wireless terminal using two paging channels that reduces standby mode power consumption described. In one embodiment of the invention, a minimally encoded quick paging channel is established over which short, quick page messages are transmitted during one of a set of quick paging slots. The quick page message indicates that a communications request has been received, and that the receiving communication terminals should process a highly encoded full paging channel over which more detailed, full page messages are transmitted during the next full paging slot. A terminal monitors full paging channel only after a quick page message has been received on the quick paging channel.Type: GrantFiled: July 9, 1997Date of Patent: May 21, 2002Assignee: Qualcomm IncorporatedInventors: Brian K. Butler, Klein S. Gilhousen
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Patent number: 6333939Abstract: A method and circuit for controlling a mobile station operating in a slotted paging environment. The circuit comprises a low power clock for generating a low frequency clock signal; a clock signal generator for generating a high frequency clock signal; a synchronization logic circuit for synchronizing the low frequency clock signal to the high frequency clock signal; a frequency error estimator for measuring an estimated low frequency clock error; and a sleep controller for removing power from the clock signal generator for the corrected sleep duration value, thereby conserving power between assigned paging slots. During the awake time, the low frequency clock signal is resynchronized to the high frequency clock, thereby correcting for any frequency error in the less accurate low power clock during sleep mode.Type: GrantFiled: August 14, 1998Date of Patent: December 25, 2001Assignee: Qualcomm IncorporatedInventors: Brian K. Butler, Nicholas K. Yu, Kenneth D. Easton
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Publication number: 20010043641Abstract: A system and method for narrowing the range of frequency uncertainty of a Doppler shifted pilot signal in a satellite or other communications system with relative signal source and receiver motion. The satellite communications system includes a user terminal (for example, a mobile wireless telephone), a gateway (terrestrial base station), and at least one satellite with unknown position and unknown relative velocity. The method includes the steps of shifting the pilot signal over a plurality of frequency hypotheses, coherently accumulating samples of the pilot signal over a plurality of chips, measuring the energy of the accumulated pilot signal samples, accumulating the energy measurements over a plurality of chips to produce an energy accumulation value, and determining which of the plurality of frequency hypotheses results in the highest energy accumulation value.Type: ApplicationFiled: June 19, 2001Publication date: November 22, 2001Inventors: Brian Harms, Sherman A. Gregory, Brian K. Butler, Avneesh Agrawal
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Publication number: 20010036828Abstract: A novel and improved method for performing paging is described. In one embodiment of the invention a searcher is used to detect spread spectrum signals. Samples received RF signals are stored in a sample buffer. During standby mode, the samples are gathered during paging slots assigned to the mobile. A set of searches are performed on the samples, and if pilot signals are detected additional demodulation is performed to detect paging messages. The resulting set of demodulation data may be combined to increase detection. After a page message has been detected, additional demodulation resources may be activated to processes more complete page messages, or other information channels. In one embodiment of the invention, the searcher includes a demodulator to perform quick page detection without the use of finger elements to reduce idle mode power consumption.Type: ApplicationFiled: April 5, 2001Publication date: November 1, 2001Inventors: Brian K. Butler, Haitao Zhang, Edward G. Tiedmann, Qiuzhen Zou, Gilbert C. Sih, Avneesh Agrawal
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Patent number: 6249539Abstract: A system and method for narrowing the range of frequency uncertainty of a Doppler shifted pilot signal in a satellite or other communications system with relative signal source and receiver motion. The satellite communications system includes a user terminal (for example, a mobile wireless telephone), a gateway (terrestrial base station), and at least one satellite with unknown position and unknown relative velocity. The method includes the steps of shifting the pilot signal over a plurality of frequency hypotheses, coherently accumulating samples of the pilot signal over a plurality of chips, measuring the energy of the accumulated pilot signal samples, accumulating the energy measurements over a plurality of chips to produce an energy accumulation value, and determining which of the plurality of frequency hypotheses results in the highest energy accumulation value.Type: GrantFiled: June 15, 1998Date of Patent: June 19, 2001Assignee: Qualcomm IncorporatedInventors: Brian Harms, Sherman A. Gregory, Brian K. Butler, Avneesh Agrawal
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Patent number: 6243561Abstract: A novel and improved method for performing paging is described. In one embodiment of the invention a searcher is used to detect spread spectrum signals. Samples received RF signals are stored in a sample buffer. During standby mode, the samples are gathered during paging slots assigned to the mobile. A set of searches are performed on the samples, and if pilot signals are detected additional demodulation is performed to detect paging messages. The resulting set of demodulation data may be combined to increase detection. After a page message has been detected, additional demodulation resources may be activated to processes more complete page messages, or other information channels. In one embodiment of the invention, the searcher includes a demodulator to perform quick page detection without the use of finger elements to reduce idle mode power consumption.Type: GrantFiled: October 13, 1998Date of Patent: June 5, 2001Assignee: Qualcomm IncorporatedInventors: Brian K. Butler, Haitao Zhang, Edward G. Tiedemann, Jr., Qiuzhen Zou, Gilbert C. Sih, Avneesh Agrawal
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Publication number: 20010000706Abstract: The certainties of transmitted bits at predetermined locations in time are determined a priori. This information is then used to set the states of a Viterbi decoder to different state metrics in accordance with the certainties of the transmitted bits. High certainty of a transmitted bit results in resetting the states corresponding to that bit to a high state metric. In contrast, low certainty of a transmitted bit results in resetting the states corresponding to that bit to a low state metric. Resetting the states to different state metrics improves the decoding performance and shortens the time required to converge the decoding trellis by eliminating improbable paths.Type: ApplicationFiled: December 20, 2000Publication date: May 3, 2001Inventors: Brian K. Butler, Gwain Bayley, David Hansquine, Edward G. Tiedemann
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Patent number: 6205186Abstract: The certainties of transmitted bits at predetermined locations in time are determine a priori. This information is then used to set the states of a Viterbi decoder to different state metrics in accordance with the certainties of the transmitted bits. High certainty of a transmitted bit results in resetting the states corresponding to that bit to a high state metric. In contrast, low certainty of a transmitted bit results in resetting the states corresponding to that bit to a low state metric. Resetting the states to different state metrics improves the decoding performance and shortens the time required to converge the decoding trellis by eliminating improbable paths.Type: GrantFiled: September 3, 1997Date of Patent: March 20, 2001Assignee: Qualcomm IncorporatedInventors: Brian K. Butler, Gwain Bayley, David Hansquine, Edward G. Tiedemann, Jr.
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Patent number: 6134215Abstract: A system and method for enabling multiple transmitters (400) to share a single code division multiplexed (CDM) or code division multiple access (CDMA) channel using orthogonal waveforms. A set of orthogonal channelizing codes W.sub.i (t) is generated, and each transmitter (400) is allocated orthogonal channelizing codes and pseudonoise polynomials in a predetermined manner. The transmitters channelize each user signal using an orthogonal channelizing code W.sub.i (t), and spread each user signal using a pseudonoise (PN) spreading code. Each transmitter employs the same PN spreading codes and time offsets. Additionally, no one orthogonal channelizing code is assigned to more than one transmitter during the time period they are sharing a CDM channel. The spread signals are summed at each transmitter (404) prior to transmission as a composite signal. The offsets are time-precorrected (406, 510) to ensure time alignment at the receivers.Type: GrantFiled: April 2, 1996Date of Patent: October 17, 2000Assignee: Qualcomm IncorpoatedInventors: Avneesh Agrawal, Brian K. Butler
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Patent number: 6111865Abstract: A novel and improved method and system for paging a cellular telephone or other wireless terminal using two paging channels that reduces standby mode power consumption described. In one embodiment of the invention, a minimally encoded quick paging channel is established over which short, quick page messages are transmitted during one of a set of quick paging slots. The quick page message indicates that a communications request has been received, and that the receiving communication terminals should process a highly encoded full paging channel over which more detailed, full page messages are transmitted during the next full paging slot. A terminal monitors full paging channel only after a quick page message has been received on the quick paging channel.Type: GrantFiled: May 30, 1997Date of Patent: August 29, 2000Assignee: Qualcomm IncorporatedInventors: Brian K. Butler, Klein S. Gilhousen
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Patent number: 5909434Abstract: A novel and improved method and apparatus for generating a constant data rate channel supporting signaling data transmission in an adjustable rate wireless communication system is described. In accordance with one aspect of the invention the rate at which the channel operates may be adjusted based on the particular use and environmental conditions such that the appropriate data rate up to a maximum capability can be achieved. User data is then placed into frames based on the selected rate. When available, signaling data is added into each frames in a predetermined amount. The resulting frame is encoded, repeated and punctured based on the selected rate and whether signaling data has been introduced, and transmitted via RF signals to the receive system. Upon reception, the frame is processed in accordance with having only user data and with having signaling data. That is, the frame is processed both as if it had signaling data and as if no signaling data were present.Type: GrantFiled: May 31, 1996Date of Patent: June 1, 1999Assignee: Qualcomm IncorporatedInventors: Joseph P. Odenwalder, Brian K. Butler, Edward G. Tiedemann, Jr., Ephraim Zehavi