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: 20090083602
    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: October 13, 2008
    Publication date: March 26, 2009
    Applicant: QUALCOMM Incorporated
    Inventors: Sandip Sarkar, Tao Chen, Edward G. Tiedemann, JR., Peter Gaal
  • Patent number: 7509500
    Abstract: In wireless communications, transmission devices require continuous supplies of random data for encryption processes. The invention provides a method for generating a continuous pool of truly random data with hardware that is already available in conventional CDMA phones.
    Type: Grant
    Filed: July 28, 2004
    Date of Patent: March 24, 2009
    Assignee: QUALCOMM Incorporated
    Inventor: Sandip Sarkar
  • Publication number: 20090054093
    Abstract: Systems and methodologies are described that facilitate employing downlink precoding based on uplink sounding channel measurement and channel reciprocity in time division duplex or time division multiplex systems. In particular, mechanism are provided that enable downlink precoding in situations where user equipment antenna configuration includes an unequal number of transmit chains and receive chains. A mobile device transmits modulated sounding reference signals on each antenna during a calibration stage. The mobile device then transmits non-modulated sounding reference signals during a normal mode. A base station utilizes the modulated and non-modulated sounding reference signals to restore a downlink channel estimate employed in downlink precoding.
    Type: Application
    Filed: August 12, 2008
    Publication date: February 26, 2009
    Applicant: QUALCOMM Incorporated
    Inventors: Byoung-Hoon Kim, Durga Prasad Malladi, Juan Montojo, Sandip Sarkar
  • Publication number: 20090046582
    Abstract: Techniques for sending traffic data and control information in a wireless communication system are described. In one design, a transmitter (e.g., a Node B or a UE) may perform beamforming to send traffic data on M layers based on a precoding matrix, where M may be one or greater. The transmitter may also perform beamforming to send control information on up to M layers based on the same precoding matrix used for the traffic data. The transmitter may send the beamformed traffic data on a first physical channel and may send the beamformed control information on a second physical channel. The transmitter may multiplex the beamformed traffic data and the beamformed control information using time division multiplexing (TDM) or frequency division multiplexing (FDM).
    Type: Application
    Filed: August 11, 2008
    Publication date: February 19, 2009
    Applicant: QUALCOMM Incorporated
    Inventors: Sandip Sarkar, Byoung-Hoon Kim, Durga Prasad Malladi, Juan Montojo
  • Publication number: 20090046570
    Abstract: Techniques for sending multiple-input multiple-output (MIMO) transmissions in wireless communication systems are described. In one design, a transmitter sends a first reference signal via a first link, e.g., a cell-specific reference signal via the downlink. The transmitter receives channel quality indicator (CQI) information determined by a receiver based on the first reference signal. The transmitter also receives a second reference signal from the receiver via a second link, e.g., a sounding reference signal via the uplink. The transmitter obtains at least one MIMO channel matrix for the first link based on the second reference signal. The transmitter determines at least one precoding matrix based on the at least one MIMO channel matrix, e.g., in accordance with ideal eigen-beamforming or pseudo eigen-beamforming. The transmitter then sends a data transmission to the receiver based on the at least one precoding matrix and the CQI information.
    Type: Application
    Filed: August 11, 2008
    Publication date: February 19, 2009
    Applicant: QUALCOMM Incorporated
    Inventors: Sandip Sarkar, Byoung-Hoon Kim, Durga Prasad Malladi, Juan Montojo
  • Publication number: 20080261582
    Abstract: Method and apparatus that provide for broadcast multicast services in an ultra mobile broadband network are disclosed. A broadcast transmission structure provides for efficient indexing of subbands reserved for BCMCS. Transmissions on the logical channels are segmented into error control blocks beginning with zero or one MAC packet received by a MAC layer. A transmitting entity appends parameters relating to content change within a next ultraframe at end of every broadcast packet that is not a stuffing packet. A mapping message of multiple Physical Layer groups addresses a single logical channel when SFN (Single Frequency Network) coverage of an associated subband group is different from SFN coverage of the logical channel.
    Type: Application
    Filed: March 26, 2008
    Publication date: October 23, 2008
    Applicant: QUALCOMM Incorporated
    Inventors: Sandip Sarkar, Naga Bhushan, Tamer Kadous, Aamod Khandekar, Parag Arun Agashe
  • Patent number: 7437648
    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: February 6, 2006
    Date of Patent: October 14, 2008
    Assignee: QUALCOMM Incorporated
    Inventors: Sandip Sarkar, Tao Chen, Edward G. Tiedemann, Jr., Peter Gaal
  • Publication number: 20080232294
    Abstract: Methods and apparatus for processing and generating broadcast messages determined by a subband and OFDM symbols of frames in which signals are received. Overhead messages indicating resources used by broadcast messages in a wireless communication system are generated. Signals are received over a wireless system and broadcast messages are determined from the signals as designated by a subband and OFDM symbols of frames of an ultraframe in which signals are received.
    Type: Application
    Filed: March 20, 2008
    Publication date: September 25, 2008
    Applicant: QUALCOMM INCORPORATED
    Inventors: Fatih Ulupinar, Parag Arun Agashe, Sandip Sarkar, Rajat Prakash
  • Publication number: 20080194286
    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: April 22, 2008
    Publication date: August 14, 2008
    Applicant: QUALCOMM Incorporated
    Inventors: Tao Chen, Stein Lundby, Sandip Sarkar, Yu-Cheun Jou
  • Publication number: 20080167040
    Abstract: Techniques for sending control information in a wireless communication system are described. A control segment may include L?1 tiles, and each tile may include a number of transmission units. A number of control resources may be defined and mapped to the transmission units for the control segment. For symmetric mapping, multiple sets of S?1 control resources may be formed, and each batch of L consecutive sets of S control resources may be mapped to S transmission units at the same location in the L tiles. For localized mapping, S>1, and each set of S control resources may be mapped to a cluster of S adjacent transmission units in one tile. For distributed mapping, S=1, and each control resource may be mapped to one transmission unit in one tile. For diversity, each control resource may be mapped to multiple (e.g., three) transmission units in at least one tile.
    Type: Application
    Filed: January 2, 2008
    Publication date: July 10, 2008
    Applicant: QUALCOMM INCORPORATED
    Inventors: Aamod Khandekar, Alexei Gorokhov, Naga Bhushan, Sandip Sarkar, Ravi Palanki
  • Patent number: 7391753
    Abstract: An improved method for facilitating handoff between an asynchronous and a synchronous base station. A method for determining a pilot channel PN offset of a pilot channel transmitted by a wireless base station. In a first embodiment, the method includes correlating a PN sequence with a received pilot signal to acquire a PN frame timing, receiving at least one search code burst aligned with the PN frame timing, the at least one search code burst signifying the pilot channel PN offset, and comparing the at least one search code burst to a set of codewords, each codeword representing a predetermined PN offset. From the search code bursts, the mobile station is able to quickly determine the PN offset of the transmitting base station, and thereby identify it. Methods for transmitting a complementary set of forward link channels are also disclosed.
    Type: Grant
    Filed: October 8, 2003
    Date of Patent: June 24, 2008
    Assignee: QUALCOMM Incorporated
    Inventors: Edward G. Tiedemann, Jr., Daisuke Terasawa, Sandip Sarkar
  • Publication number: 20080101322
    Abstract: Methods and apparatus are disclosed for generating and exchanging codebooks in a multiple access wireless communication system. The codebooks include a plurality of preferred precoding matrices.
    Type: Application
    Filed: October 25, 2007
    Publication date: May 1, 2008
    Applicant: QUALCOMM INCORPORATED
    Inventors: Rajat Prakash, Sandip Sarkar
  • Publication number: 20080025241
    Abstract: A method and apparatus for broadcast multicast service in an ultra mobile broadband network is provided. An apparatus is provided which is operable in a wireless communication system to provide a means for mapping broadcast flows to a broadcast multicast logical channel and transmitting the broadcast multicast logic channel on an aggregation of broadcast physical channels, where each of the aggregation of the broadcast physical channels is uniquely characterized. Radio configurations to support the ultra mobile broadband network are also provided.
    Type: Application
    Filed: July 27, 2007
    Publication date: January 31, 2008
    Inventors: Naga Bhushan, Parag Agashe, Sandip Sarkar, Tamer Kadous
  • Patent number: 7315527
    Abstract: Embodiments disclosed herein address the need in the art for an extended acknowledgment/rate control channel. In one aspect, an acknowledgment command and a rate control command are combined to form a combined command. In another aspect, the combined command is generated in accordance with a constellation of points, each point corresponding to a pair consisting of a rate control command and an acknowledgment command. In yet another aspect, the points of the constellation are designed to provide the desired probability of error for the respective command pairs. In yet another aspect, a common rate control command is transmitted along with a combined or dedicated rate control command. Various other aspects are also presented. These aspects have the benefit of reduced overhead while providing acknowledgment and rate control to single remote stations and/or groups of remote stations.
    Type: Grant
    Filed: February 17, 2004
    Date of Patent: January 1, 2008
    Assignee: Qualcomm Incorporated
    Inventors: Yongbin Wei, Edward G. Tiedemann, Jr., Peter Gaal, Durga P. Malladi, David Puig Oses, Sandip Sarkar, Stein Lundby, Tao Chen, Avinash Jain, Aleksandar Damnjanovic, Serge Willenegger
  • Patent number: 7298718
    Abstract: Systems and techniques for communications include calculating a value from data, transmitting the value and data over at least one time slot, receiving the transmission, recalculating the value from the received data, and determining the number of time slots of the transmission from the calculated and recalculated values. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or the meaning of the claims.
    Type: Grant
    Filed: March 25, 2002
    Date of Patent: November 20, 2007
    Assignee: QUALCOMM Incorporated
    Inventors: Joseph P. Odenwalder, Yongbin Wei, Edward G. Tiedemann, Jr., Stein A. Lundby, David Puig-Oses, Sandip Sarkar
  • Patent number: 7286846
    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: Grant
    Filed: August 29, 2003
    Date of Patent: October 23, 2007
    Assignee: QUALCOMM, Incorporated
    Inventors: Tao Chen, Stein Lundby, Sandip Sarkar, Yu-Cheun Jou
  • Publication number: 20070223514
    Abstract: Rather than attaching a preamble to a data traffic subpacket, a preamble channel is transmitted along with a traffic channel. In a system wherein the data traffic subpackets are variably sized, preambles can also be variably sized if a target station can decode variably sized preambles. A method and apparatus for decoding variably sized preamble subpackets are presented herein.
    Type: Application
    Filed: June 1, 2007
    Publication date: September 27, 2007
    Applicant: QUALCOMM Incorporated
    Inventors: Joseph Odenwalder, Sandip Sarkar, Yongbin Wei
  • Publication number: 20070206623
    Abstract: Embodiments disclosed herein address the need in the art for reduced overhead control with the ability to adjust transmission rates as necessary. In one aspect, a first signal indicates an acknowledgement of a decoded subpacket and whether or not a rate control command is generated, and a second signal conditionally indicates the rate control command when one is generated. In another aspect, a grant may be generated concurrently with the acknowledgement. In yet another aspect, a mobile station monitors the first signal, conditionally monitors the second signal as indicated by the first signal, and may monitor a third signal comprising a grant. In yet another aspect, one or more base stations transmit one or more of the various signals. Various other aspects are also presented. These aspects have the benefit of providing the flexibility of grant-based control while utilizing lower overhead when rate control commands are used, thus increasing system utilization, increasing capacity and throughput.
    Type: Application
    Filed: May 10, 2007
    Publication date: September 6, 2007
    Applicant: QUALCOMM, INCORPORATED
    Inventors: Edward Tiedemann, Aleksandar Damnjanovic, Avinash Jain, Durga Malladi, David Oses, Peter Gaal, Stein Lundby, Sandip Sarkar, Tao Chen, Yongbin Wei, Serge Willenegger
  • Patent number: 7230941
    Abstract: Rather than attaching a preamble to a data traffic subpacket, a preamble channel is transmitted along with a traffic channel. In a system wherein the data traffic subpackets are variably sized, preambles can also be variably sized if a target station can decode variably sized preambles. A method and apparatus for decoding variably sized preamble subpackets are presented herein.
    Type: Grant
    Filed: April 26, 2001
    Date of Patent: June 12, 2007
    Assignee: QUALCOMM Incorporated
    Inventors: Joseph P. Odenwalder, Sandip Sarkar, Yongbin Wei
  • Publication number: 20070111747
    Abstract: An apparatus, system, and method efficiently manage reverse link resources by allowing a mobile station to select between transmitting a payload at 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: January 9, 2007
    Publication date: May 17, 2007
    Applicant: QUALCOMM INCORPORATED
    Inventors: Stein Lundby, Avinash Jain, Joseph Odenwalder, Sandip Sarkar, Tao Chen, Yongbin Wei