Patents by Inventor Rajiv Vijayan

Rajiv Vijayan 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: 10064179
    Abstract: Techniques for managing peak-to-average power ratio (PAPR) for multi-carrier modulation in wireless communication systems. Different terminals in a multiple-access system may have different required transmit powers. The number of carriers to allocate to each terminal is made dependent on its required transmit power. Terminals with higher required transmit powers may be allocated fewer carriers (associated with smaller PAPR) to allow the power amplifier to operate at higher power levels. Terminals with lower required transmit powers may be allocated more carriers (associated with higher PAPR) since the power amplifier is operated at lower power levels. The specific carriers to assign to the terminals may also be determined by their transmit power levels to reduce out-of-band emissions. Terminals with higher required transmit powers may be assigned with carriers near the middle of the operating band, and terminals with lower required transmit powers may be assigned with carriers near the band edges.
    Type: Grant
    Filed: November 19, 2009
    Date of Patent: August 28, 2018
    Assignee: QUALCOMM Incorporated
    Inventors: Rajiv Vijayan, Avneesh Agrawal, Sanjay Jha
  • Patent number: 9668206
    Abstract: Techniques for multiplexing and transmitting multiple data streams are described. Transmission of the multiple data streams occurs in “super-frames”. Each super-frame has a predetermined time duration and is further divided into multiple (e.g., four) frames. Each data block for each data stream is outer encoded to generate a corresponding code block. Each code block is partitioned into multiple subblocks, and each data packet in each code block is inner encoded and modulated to generate modulation symbols for the packet. The multiple subblocks for each code block are transmitted in the multiple frames of the same super-frame, one subblock per frame. Each data stream is allocated a number of transmission units in each super-frame and is assigned specific transmission units to achieve efficient packing. A wireless device can select and receive individual data streams.
    Type: Grant
    Filed: October 18, 2013
    Date of Patent: May 30, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Rajiv Vijayan, Aamod Khandekar, Fuyun Ling, Gordon Kent Walker, Murali Ramaswamy Chari
  • Patent number: 9544897
    Abstract: Techniques for managing peak-to-average power ratio (PAPR) for multi-carrier modulation in wireless communication systems. Different terminals in a multiple-access system may have different required transmit powers. The number of carriers to allocate to each terminal is made dependent on its required transmit power. Terminals with higher required transmit powers may be allocated fewer carriers (associated with smaller PAPR) to allow the power amplifier to operate at higher power levels. Terminals with lower required transmit powers may be allocated more carriers (associated with higher PAPR) since the power amplifier is operated at lower power levels. The specific carriers to assign to the terminals may also be determined by their transmit power levels to reduce out-of-band emissions. Terminals with higher required transmit powers may be assigned with carriers near the middle of the operating band, and terminals with lower required transmit powers may be assigned with carriers near the band edges.
    Type: Grant
    Filed: April 15, 2013
    Date of Patent: January 10, 2017
    Assignee: QUALCOMM Incorporated
    Inventors: Rajiv Vijayan, Avneesh Agrawal, Sanjay Jha
  • Patent number: 9391751
    Abstract: A system and method for frequency diversity uses interleaving in a wireless communication system utilizing orthogonal frequency division multiplexing (OFDM) with various FFT sizes. Subcarriers of one or more interlaces are interleaved in a bit reversal fashion and the one or more interlaces are interleaved.
    Type: Grant
    Filed: July 24, 2008
    Date of Patent: July 12, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Ashok Mantravadi, Murali Ramaswamy Chari, Michael Mao Wang, Fuyun Ling, Rajiv Vijayan, Raghuraman Krishnamoorthi
  • Patent number: 9356752
    Abstract: The embodiments utilize OFDM symbols to communicate network IDs. The IDs are encoded into symbols utilizing the network IDs as seeds to scramble respective pilots that are then transmitted by utilizing the symbols. The pilots can be structured into a single OFDM symbol and/or multiple OFDM symbols. The single symbol structure for transmitting the network IDs is independent of the number of network ID bits and minimizes frequency offset and Doppler effects. The multiple symbol structure allows a much coarser timing accuracy to be employed at the expense of transmitting additional symbols. Several embodiments employ a search function to find possible network ID candidates from a transmitted symbol and a selection function to find an optimum candidate from a network ID candidate list.
    Type: Grant
    Filed: November 18, 2010
    Date of Patent: May 31, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Michael Mao Wang, Bojan Vrcelj, Krishna Kiran Mukkavilli, Raghuraman Krishnamoorthi, Rajiv Vijayan
  • Patent number: 9246728
    Abstract: A system and method for frequency diversity uses interleaving in a wireless communication system utilizing orthogonal frequency division multiplexing (OFDM) with various FFT sizes. Subcarriers of one or more interlaces are interleaved in a bit reversal fashion and the one or more interlaces are interleaved in the bit reversal fashion.
    Type: Grant
    Filed: February 14, 2013
    Date of Patent: January 26, 2016
    Assignee: QUALCOMM Incorporated
    Inventors: Michael Mao Wang, Murali Ramaswamy Chari, Ashok Mantravadi, Fuyun Ling, Rajiv Vijayan, Raghuraman Krishnamoorthi
  • Patent number: 9155106
    Abstract: Techniques to more efficiently transmit pilot and signaling on the uplink in an OFDM system. With subband multiplexing, M usable subbands in the system are partitioned into Q disjoint groups of subbands. Each subband group may be assigned to a different terminal for uplink pilot transmission. Multiple terminals may transmit simultaneously on their assigned subbands. The transmit power for the pilot may be scaled higher to attain the same total pilot energy even though S instead of M subbands are used for pilot transmission by each terminal. Pilot transmissions from the terminals are received, and a channel estimate is derived for each terminal based on the pilot received on the assigned subbands. The channel estimate comprises a response for additional subbands not included in the assigned group. Subband multiplexing may also be used for uplink signaling transmission.
    Type: Grant
    Filed: January 23, 2014
    Date of Patent: October 6, 2015
    Assignee: QUALCOMM Incorporated
    Inventors: Ranganathan Krishnan, Rajiv Vijayan, Tamer Adel Kadous
  • Patent number: 9118111
    Abstract: Calibration for a transmit chain of a device transmitting information to multiple devices over wireless links includes selecting from between two or more calibration determination techniques. In certain aspects the techniques include phase only calibration and phase and amplitude calibration.
    Type: Grant
    Filed: April 17, 2006
    Date of Patent: August 25, 2015
    Assignee: QUALCOMM Incorporated
    Inventors: Ayman Fawzy Naguib, Alexei Gorokhov, Rajiv Vijayan
  • Patent number: 9042461
    Abstract: Systems and methods are provided for transmitting OFDM information via IFFT up-sampling components that transmit data at a higher sampling rate than conventional systems to simplify filter requirements and mitigate leakage between symbols. In one embodiment, an NL point IFFT is performed on a zero inserted set of frequency domain symbols. In another embodiment, the NL point IFFT is further optimized by exploiting the fact that (N?1) L of the frequency domain symbols are zero. This enables an embodiment that consists of a pre-processor that multiplies the input samples by complex phase factors, followed by L point IFFTs.
    Type: Grant
    Filed: March 9, 2006
    Date of Patent: May 26, 2015
    Assignee: QUALCOMM Incorporated
    Inventors: Raghuraman Krishnamoorthi, Fuyun Ling, Rajiv Vijayan
  • Patent number: 9003243
    Abstract: A system and method for modulation diversity uses interleaving. Code bits are placed into groups and are then shuffled within each group.
    Type: Grant
    Filed: July 29, 2005
    Date of Patent: April 7, 2015
    Assignee: QUALCOMM Incorporated
    Inventors: Michael Mao Wang, Fuyun Ling, Murali Ramaswamy Chari, Rajiv Vijayan
  • Patent number: 8948329
    Abstract: Apparatus and methods for use in a wireless communication system are disclosed for recovery of timing tracking in a device, such as a wireless transceiver, after decoding errors occur due to incorrect timing tracking. In particular, the disclosed methods and apparatus recover timing tracking by monitoring a decoded signal in the transceiver for decoding errors occurring during a first frame, determining whether a number of decoding errors is greater than a predetermined amount, reacquiring a first pilot channel at a start of a subsequently received second frame when the number of decoding errors is determined to be greater than the predetermined amount, and resetting timing tracking of the transceiver based on the reacquired first pilot channel.
    Type: Grant
    Filed: December 15, 2005
    Date of Patent: February 3, 2015
    Assignee: QUALCOMM Incorporated
    Inventors: Michael Mao Wang, Bojan Vrcelj, Fuyun Ling, Rajiv Vijayan
  • Patent number: 8879979
    Abstract: Techniques to seamlessly switch reception between multimedia programs are described. For “continued decoding”, a wireless device continues to receive, decode, decompress, and (optionally) display a current program until overhead information needed to decode the new program is received. For “early decoding”, the wireless device receives a user input and identifies a program with potential for user selection. The wireless device initiates decoding of the identified program, prior to its selection, so that the program can be decompressed and displayed earlier if it is subsequently selected. For time-compensated transmission, a base station transmits video and audio for a program in a manner to account for the difference between audio processing delay and video processing delay at the wireless device. This allows the wireless device to present the audio earlier during a program change, since its processing delay is shorter, and thus provide a faster response to the program change.
    Type: Grant
    Filed: August 15, 2011
    Date of Patent: November 4, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Murali Ramaswamy Chari, Gordon Kent Walker, Rajiv Vijayan
  • Patent number: 8874998
    Abstract: A wireless communication apparatus in a hierarchically coded modulation system can use error control mechanisms generated during decoding of base layer information to predict a probability of successful demodulation of enhancement layer information. Performance in the demodulation of the base layer correlates to performance in the demodulation of the enhancement layer. The receiver can determine whether to attempt demodulation of temporally correlated enhancement layer data based in part on the predicted probability of success. If the receiver determines not to demodulate the enhancement layer, the receiver can power down the enhancement layer demodulator, or otherwise minimize the power expended in the enhancement layer demodulator.
    Type: Grant
    Filed: May 17, 2009
    Date of Patent: October 28, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Gordon Kent Walker, Rajiv Vijayan, Seong Taek Chung, Murali Ramaswamy Chari, Fuyun Ling
  • Patent number: 8842619
    Abstract: To support mobile stations that are not capable of demodulating the entire bandwidth or that can be made to demodulate less than the entire bandwidth, a system, apparatus and method are provided to schedule users on less than all of the bandwidth. Further, certain users can be scheduled on more of the bandwidth than others.
    Type: Grant
    Filed: July 7, 2011
    Date of Patent: September 23, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Aamod Dinkar Khandekar, Alexei Yurievitch Gorokhov, Avneesh Agrawal, Rajiv Vijayan, Edward Harrison Teague, Fatih Ulupinar
  • Patent number: 8826093
    Abstract: Conserving power for coded transmissions comprises ceasing to process parity packets once associated data packets are deemed correct or corrected. Once data packets are deemed correct or corrected, the receiving unit can shut off during the transmission of parity packets.
    Type: Grant
    Filed: January 18, 2006
    Date of Patent: September 2, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Gordon Kent Walker, Chinnappa K. Ganapathy, Dhinakar Radhakrishnan, Fuyun Ling, Rajiv Vijayan
  • Patent number: 8811973
    Abstract: Techniques for managing peak-to-average power ratio (PAPR) for multi-carrier modulation in wireless communication systems. Different terminals in a multiple-access system may have different required transmit powers. The number of carriers to allocate to each terminal is made dependent on its required transmit power. Terminals with higher required transmit powers may be allocated fewer carriers (associated with smaller PAPR) to allow the power amplifier to operate at higher power levels. Terminals with lower required transmit powers may be allocated more carriers (associated with higher PAPR) since the power amplifier is operated at lower power levels. The specific carriers to assign to the terminals may also be determined by their transmit power levels to reduce out-of-band emissions. Terminals with higher required transmit powers may be assigned with carriers near the middle of the operating band, and terminals with lower required transmit powers may be assigned with carriers near the band edges.
    Type: Grant
    Filed: July 10, 2008
    Date of Patent: August 19, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Rajiv Vijayan, Avneesh Agrawal, Sanjay Jha
  • Patent number: 8737470
    Abstract: A wireless communication apparatus in a hierarchically coded modulation system can use error control mechanisms generated during decoding of base layer information to predict a probability of successful demodulation of enhancement layer information. Performance in the demodulation of the base layer correlates to performance in the demodulation of the enhancement layer. The receiver can determine whether to attempt demodulation of temporally correlated enhancement layer data based in part on the predicted probability of success. If the receiver determines not to demodulate the enhancement layer, the receiver can power down the enhancement layer demodulator, or otherwise minimize the power expended in the enhancement layer demodulator.
    Type: Grant
    Filed: May 11, 2010
    Date of Patent: May 27, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Gordon Kent Walker, Rajiv Vijayan, Seong Taek Chung, Murali Ramaswamy Chari, Fuyun Ling
  • Patent number: 8738614
    Abstract: System for providing hierarchical services in a data network. A method is provided for inserting content into a content stream for rendering on a device. The method includes obtaining one or more annotation parameters that comprise a content identifier, and determining an insertion point indicator that indicates a location in the content stream. The method also includes retrieving the content based on the content identifier, and inserting the content in the content stream at a location indicated by the insertion point indicator.
    Type: Grant
    Filed: April 21, 2005
    Date of Patent: May 27, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Gordon Kent Walker, George Alan Wiley, Ricardo Jorge Lopez, Richard Doil Lane, Rajiv Vijayan
  • Publication number: 20140133450
    Abstract: Techniques to more efficiently transmit pilot and signaling on the uplink in an OFDM system. With subband multiplexing, M usable subbands in the system are partitioned into Q disjoint groups of subbands. Each subband group may be assigned to a different terminal for uplink pilot transmission. Multiple terminals may transmit simultaneously on their assigned subbands. The transmit power for the pilot may be scaled higher to attain the same total pilot energy even though S instead of M subbands are used for pilot transmission by each terminal. Pilot transmissions from the terminals are received, and a channel estimate is derived for each terminal based on the pilot received on the assigned subbands. The channel estimate comprises a response for additional subbands not included in the assigned group. Subband multiplexing may also be used for uplink signaling transmission.
    Type: Application
    Filed: January 23, 2014
    Publication date: May 15, 2014
    Applicant: QUALCOMM Incorporated
    Inventors: Ranganathan KRISHNAN, Rajiv VIJAYAN, Tamer Adel KADOUS
  • Patent number: 8724555
    Abstract: Techniques to more efficiently transmit pilot and signaling on the uplink in an OFDM system. With subband multiplexing, M usable subbands in the system are partitioned into Q disjoint groups of subbands. Each subband group may be assigned to a different terminal for uplink pilot transmission. Multiple terminals may transmit simultaneously on their assigned subbands. The transmit power for the pilot may be scaled higher to attain the same total pilot energy even though S instead of M subbands are used for pilot transmission by each terminal. Pilot transmissions from the terminals are received, and a channel estimate is derived for each terminal based on the pilot received on the assigned subbands. The channel estimate comprises a response for additional subbands not included in the assigned group. Subband multiplexing may also be used for uplink signaling transmission.
    Type: Grant
    Filed: May 4, 2006
    Date of Patent: May 13, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Ranganathan Krishnan, Rajiv Vijayan, Tamer Kadous