Patents by Inventor Sandip Sarkar

Sandip Sarkar 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).

  • Publication number: 20070030820
    Abstract: A method for power control in a wireless communication system. An initial transmission of a data frame in the reverse link is received, and a first energy level of the data frame is measured. An energy deficit in the first energy level is then measured if the first energy level is insufficient to correctly decode the data frame, so that when the data frame is retransmitted with a second energy level equal to a difference between the first energy level and the energy deficit, the data frame can be correctly decoded with combined energy of the first energy level and the second energy level.
    Type: Application
    Filed: October 10, 2006
    Publication date: February 8, 2007
    Inventors: Sandip Sarkar, Tao Chen, Edward Tiedemann
  • Patent number: 7170876
    Abstract: Methods and apparatus are presented for dynamically adjusting parameters of an outer-loop algorithm, which is used to determine the feasibility of a transmission format. The parameters of the outer-loop algorithm are adjusted according to channel conditions. In one embodiment, an erasure-based approach is used to determine whether to incrementally increase or incrementally decrease a margin parameter in the outer-loop algorithm. Once one margin parameter is altered, other margin parameters can be adjusted accordingly.
    Type: Grant
    Filed: April 30, 2002
    Date of Patent: January 30, 2007
    Assignee: Qualcomm, Inc.
    Inventors: Yongbin Wei, Jack M. Holtzman, Gang Bao, Sandip Sarkar, David Puig-Oses
  • Patent number: 7170996
    Abstract: In wireless communications, transmission devices require continuous supplies of random data for encryption processes. The invention provides a method for generating a continuos pool of truly random data with hardware that is already available in conventional CDMA phones.
    Type: Grant
    Filed: October 18, 1999
    Date of Patent: January 30, 2007
    Assignee: Qualcomm Incorporated
    Inventor: Sandip Sarkar
  • Publication number: 20070014401
    Abstract: In wireless communications, transmission devices require continuous supplies of random data for encryption processes. The invention provides a method for generating a continuos pool of truly random data with hardware that is already available in conventional CDMA phones.
    Type: Application
    Filed: October 18, 1999
    Publication date: January 18, 2007
    Inventor: SANDIP SARKAR
  • Patent number: 7155249
    Abstract: A method for power control in a wireless communication system. An initial transmission of a data frame in the reverse link is received, and a first energy level of the data frame is measured. An energy deficit in the first energy level is then measured if the first energy level is insufficient to correctly decode the data frame, so that when the data frame is retransmitted with a second energy level equal to a difference between the first energy level and the energy deficit, the data frame can be correctly decoded with combined energy of the first energy level and the second energy level.
    Type: Grant
    Filed: January 10, 2003
    Date of Patent: December 26, 2006
    Assignee: Qualcomm Incorporated
    Inventors: Sandip Sarkar, Tao Chen, Edward G. Tiedemann, Jr.
  • Publication number: 20060255989
    Abstract: Techniques for selecting transmit formats in a manner to account for the degrees of resource reuse for multiple data streams sent simultaneously from multiple antennas are described. The degree of resource reuse for each data stream indicates the amount of reuse of resources (e.g., orthogonal codes or subcarriers) observed by that stream. Interference estimates for the multiple data streams are derived based on an initial resource assignment. The degrees of resource reuse are determined based on the interference estimates and are used to derive at least one correction factor. At least one transmit format is then selected for the data streams using the at least one correction factor. Each data stream is associated with a transmit format that indicates the amount of resources to use for the data stream and other parameters. Resources are assigned to each data stream in accordance with its transmit format.
    Type: Application
    Filed: April 21, 2006
    Publication date: November 16, 2006
    Inventors: Byoung-Hoon Kim, Durga Malladi, Sandip Sarkar
  • Patent number: 7126928
    Abstract: Embodiments disclosed herein address the need in the art for efficient management of grant, acknowledgement, and rate control channels. In one aspect, a list associated with a first station is generated or stored, the list comprising zero or more identifiers, each identifier identifying one of a plurality of second stations for sending a message to the first station. In another aspect, sets of lists for one or more first stations are generated or stored. In yet another aspect, the messages may be acknowledgements, rate control commands, or grants. In yet another aspect, messages comprising one or more identifiers in the list are generated. Various other aspects are also presented. These aspects have the benefit of reduced overhead while managing grant, acknowledgment and rate control messaging for one or more remote stations.
    Type: Grant
    Filed: February 19, 2004
    Date of Patent: October 24, 2006
    Assignee: Qualcomm Incorporated
    Inventors: Edward G. Tiedemann, Jr., Aleksandar Damnjanovic, Avinash Jain, Durga P. Malladi, David Puig Oses, Peter Gaal, Serge Willenegger, Stein Lundby, Sandip Sarkar, Tao Chen, Yongbin Wei
  • Publication number: 20060156166
    Abstract: An acknowledgement method in a wireless communication system. Initially, a reverse supplemental channel (R-SCH) frame is received at a base station. The base station then transmits an acknowledgement (ACK) signal if quality of the received R-SCH frame is indicated as being good. A negative acknowledgement (NAK) signal is transmitted only if the received data frame is indicated as being bad but has enough energy such that, if combined with energy from retransmission of the data frame, it would be sufficient to permit correct decoding of the data frame. If the best base station is known, the acknowledgement method may reverse the transmission of the acknowledgement signals for the best base station so that only NAK signal is sent. A positive acknowledgement is assumed in the absence of an acknowledgement. This is done to minimize the transmit power requirements.
    Type: Application
    Filed: February 6, 2006
    Publication date: July 13, 2006
    Inventors: Sandip Sarkar, Tao Chen, Edward Tiedemann, Peter Gaal
  • Publication number: 20060098718
    Abstract: A wireless telecommunications system includes a base station, a plurality of remote stations, a first channel for general page messages containing paging information and broadcast databurst message references, and an auxiliary channel for broadcast databurst notification indicators for the purpose of increasing standby time in remote stations configured to receive broadcast databurst messages.
    Type: Application
    Filed: December 19, 2005
    Publication date: May 11, 2006
    Inventors: Sandip Sarkar, Edward Tiedemann, Jun Wang
  • Patent number: 6999430
    Abstract: Methods and apparatus are presented for scheduling data packet transmissions during optimal channel conditions. In one method, data packet retransmissions are scheduled for transmission during favorable channel conditions when the target remote station is moving slowly, but are scheduled for periodic transmissions when the target is moving moderately or fast. In another method, long delays for retransmissions in a channel sensitive timing scheme are eliminated. In other methods, a combination of periodic and aperiodic retransmissions are used to achieve the desired frame error rate.
    Type: Grant
    Filed: November 30, 2000
    Date of Patent: February 14, 2006
    Assignee: Qualcomm Incorporated
    Inventors: Jack M. Holtzman, Sandip Sarkar, Ahmed Saifuddin
  • Patent number: 6996763
    Abstract: An acknowledgement method in a wireless communication system. Initially, a reverse supplemental channel (R-SCH) frame is received at a base station. The base station then transmits an acknowledgement (ACK) signal if quality of the received R-SCH frame is indicated as being good. A negative acknowledgement (NAK) signal is transmitted only if the received data frame is indicated as being bad but has enough energy such that, if combined with energy from retransmission of the data frame, it would be sufficient to permit correct decoding of the data frame. If the best base station is known, the acknowledgement method may reverse the transmission of the acknowledgement signals for the best base station so that only NAK signal is sent. A positive acknowledgement is assumed in the absence of an acknowledgement. This is done to minimize the transmit power requirements.
    Type: Grant
    Filed: January 10, 2003
    Date of Patent: February 7, 2006
    Assignee: Qualcomm Incorporated
    Inventors: Sandip Sarkar, Tao Chen, Edward G. Tiedemann, Jr., Peter Gaal
  • Patent number: 6990091
    Abstract: A method and apparatus for quickly acquiring synchronization of a signal in a WCDMA communication system utilizing variable duration sample accumulation, validity testing of decoder estimates, and parallel decoding of multiple synchronization signals within a PERCH channel. The receiver accumulates the samples necessary to reliably determine slot timing. Until slot timing estimates pass a validity test, samples are accumulated for frame timing estimates. Until frame timing estimates pass a validity test, samples are analyzed to determine the pilot offset of the channel.
    Type: Grant
    Filed: October 26, 2001
    Date of Patent: January 24, 2006
    Assignee: Qualcomm Incorporated
    Inventor: Sandip Sarkar
  • Patent number: 6982971
    Abstract: A method and system that enables faster acquisition of the forward link signal of a target base station in a mixed network of synchronous and asynchronous base stations is disclosed. The serving base station transmits in a neighbor list an estimated timing error 417 between the serving base station and a target base station. By utilizing the timing information, a mobile station estimates the relative time offset 408 between forward link signals received from the serving base station and signals received from the target base station. Timing information acquired during handoff enables accurate updating of the estimated timing error 417 subsequently transmitted in the neighbor lists by the base stations.
    Type: Grant
    Filed: March 15, 2001
    Date of Patent: January 3, 2006
    Assignee: QUALCOMM Incorporated
    Inventors: Edward G. Tiedemann, Jr., Daisuke Terasawa, Sandip Sarkar, Yu-Cheun Jou, Joseph P. Odenwalder
  • Patent number: 6977957
    Abstract: A wireless telecommunications system includes a base station, a plurality of remote stations, a first channel for general page messages containing paging information and broadcast databurst message references, and an auxiliary channel for broadcast databurst notification indicators for the purpose of increasing standby time in remote stations configured to receive broadcast databurst messages.
    Type: Grant
    Filed: November 5, 2003
    Date of Patent: December 20, 2005
    Assignee: Qualcomm Incorporated
    Inventors: Sandip Sarkar, Edward G. Tiedemann, Jr., Jun Wang
  • Publication number: 20050197150
    Abstract: A method and apparatus for adaptively controlling the power level of transmissions from a remote station by determining the velocity of the remote station. A general classification of the velocity of the remote station can be used to selectively implement a closed loop power control scheme. Power level parameters are used to determine velocity. In accordance with a classification of stationary, low speed, or high speed, the closed loop power control is selectively operated. Velocity can be determined by either the base station or the remote station through various methods. One method is the use of power control bits and/or average power to determine level crossings and excursion times.
    Type: Application
    Filed: February 14, 2005
    Publication date: September 8, 2005
    Inventors: Sandip Sarkar, Yu-Cheun Jou
  • Publication number: 20050190718
    Abstract: Methods and apparatus are presented for scheduling data packet transmissions during optimal channel conditions. In one method, data packet retransmissions are scheduled for transmission during favorable channel conditions when the target remote station is moving slowly, but are scheduled for periodic transmissions when the target is moving moderately or fast. In another method, long delays for retransmissions in a channel sensitive timing scheme are eliminated. In other methods, a combination of periodic and aperiodic retransmissions are used to achieve the desired frame error rate.
    Type: Application
    Filed: October 8, 2004
    Publication date: September 1, 2005
    Inventors: Jack Holtzman, Sandip Sarkar, Ahmed Saifuddin
  • Patent number: 6934318
    Abstract: A sequence of code symbols is supplied to a rate decision block. The sequence of code symbols can be output from a Viterbi decoder, and may correspond to block encoded and convolutional encoded output from a vocoder, produced in data frames at varying data rates, or frame rates, unknown to the decoder or to the rate decision block. The rate decision block determines a number of frame energies based on the sequence of code symbols, where each frame energy corresponds to a tentative frame rate. Each frame energy can be determined, by measuring the power and duration of each code symbol based on the tentative frame rate, to determine the tentative energy of each code symbol in a frame, and then adding the tentative energies of all the code symbols in the frame. The rate decision block determines a final frame rate when the frame energies meets a desired condition.
    Type: Grant
    Filed: December 22, 2000
    Date of Patent: August 23, 2005
    Assignee: Qualcomm, Incorporated
    Inventor: Sandip Sarkar
  • Publication number: 20050176456
    Abstract: Systems and methods for controlling the power level for a mobile station during periods when no data is being transmitted by the mobile station. In one embodiment, data is intermittently transmitted from a mobile station to a base station on a reverse-link traffic channel. When data is being transmitted on the traffic channel, the transmitted data is used by the base station to perform power control operations (e.g., incrementing or decrementing the mobile station's power level, based upon comparison of a received SNR to a target SNR). When no data is being transmitted on the traffic channel, a “zero-rate indicator” is transmitted on the rate indicator channel. The zero-rate indicator is used by the base station to perform power control. Power control based on the zero-rate indicator may use velocity profiles, reliability metrics or other techniques to control adjustment of the power level.
    Type: Application
    Filed: March 17, 2005
    Publication date: August 11, 2005
    Inventors: Tao Chen, Stein Lundby, Sandip Sarkar, Yu-Cheun Jou
  • Publication number: 20050124372
    Abstract: In accordance with an exemplary embodiment of the invention, an apparatus, system, and method efficiently manage reverse link resources by allowing a mobile station to select between transmitting a payload a standard power level and transmitting a smaller payload at a boosted power level. The mobile station, therefore, can autonomously select a QoS (Quality of Service) level for physical layer packets. Based on reverse link transmission information received from a base station, the mobile station derives a reverse link transmission guideline defining the power levels and associated payloads for at least a standard service and boosted service. The mobile station selects a reverse link transmission power level from a plurality of power levels including at least a standard reverse link transmission power level associated with a standard payload size and a boosted reverse link transmission power level associated with a boosted payload size where the standard payload size is greater than the boosted payload size.
    Type: Application
    Filed: September 2, 2004
    Publication date: June 9, 2005
    Inventors: Stein Lundby, Avinash Jain, Joseph Odenwalder, Sandip Sarkar, Tao Chen, Yongbin Wei
  • Patent number: 6873647
    Abstract: A method and system for generating forward link channels in a synchronous CDMA base station having a pilot pseudonoise (PN) sequence with a pilot PN sequence offset. In one embodiment the method includes the steps of generating a sync channel including a sync channel message; generating an identification channel including at least the pilot PN sequence offset; and orthogonalizing the sync channel and the identification channel. The identification channel and the sync channel are both transmitted. However, the mobile station may get the pilot PN offset from the identification channel quickly, rather than having to demodulate the entire sync channel message. The identification channel may further include an indication of the phase of the pilot PN sequence, and the epoch of the pilot PN sequence. In one embodiment, the method includes encoding the identification channel using a Golay code.
    Type: Grant
    Filed: November 5, 1999
    Date of Patent: March 29, 2005
    Assignee: Qualcomm Incorporated
    Inventors: Edward G. Tiedemann, Jr., Daisuke Terasawa, Abhijit G. Shanbhag, Yu-Cheun Jou, Joseph P. Odenwalder, Serge Willenegger, Sandip Sarkar