Patents by Inventor Durga Malladi

Durga Malladi 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: 8811373
    Abstract: Systems, methodologies, and devices are described that facilitate transmitting a guard time parameter to a mobile device to facilitate rate matching data around a guard time region associated with a downlink subframe of a radio frame sequence. A base station transmits the guard time parameter via PBCH or DBCH to the mobile device. The base station rate matches data associated with PDSCH, comprising DBCH, around the guard time region, and transmits PDSCH to the mobile device. The mobile device identifies the guard time parameter and rate matches at least a portion of the information received via the PDSCH around the guard time region to facilitate enhanced reception of PDSCH. Optionally, a radio frame sequence can be structured so that a subframe immediately following a subframe containing DBCH is a downlink subframe, which can be known by the mobile device a priori or based on a downlink subframe parameter.
    Type: Grant
    Filed: August 13, 2008
    Date of Patent: August 19, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Durga Malladi, Juan Montojo
  • Patent number: 8681666
    Abstract: Techniques for performing partial cyclic prefix discarding are described. A user equipment (UE) may reduce the amount of cyclic prefix to discard for the last OFDM symbol prior to a switch from data reception to data transmission. This may allow the UE to complete data reception earlier and to switch to data transmission in a timely manner. In one design, the UE may receive a first OFDM symbol and discard a first amount of cyclic prefix for the first OFDM symbol. The UE may then receive a second OFDM symbol and discard a second amount of cyclic prefix for the second OFDM symbol. The second amount of cyclic prefix to discard may be determined based on the amount of time needed to switch from data reception to data transmission, which may be dependent on the amount of time advance between transmit timing and receive timing at the UE.
    Type: Grant
    Filed: September 8, 2008
    Date of Patent: March 25, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Juan Montojo, Durga Malladi, Shimman Patel
  • Patent number: 8514909
    Abstract: Noise measurements are made within a fraction of a single symbol period of a longest orthogonal code symbol. A control processor identifies an unoccupied code having a spreading factor that is less than a longest spreading factor for the system. A despreader measures symbol energy based on the unoccupied code and a noise estimator generates noise estimations based on the measured symbol energies. The subscriber station uses similar techniques in order to perform channel estimations within a period that is a fraction of a symbol period of a longest-spreading-factor code.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: August 20, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Da-Shan Shiu, Durga Malladi Prasad, Srikrishna Bhashyam
  • Publication number: 20090122731
    Abstract: Techniques for performing partial cyclic prefix discarding are described. A user equipment (UE) may reduce the amount of cyclic prefix to discard for the last OFDM symbol prior to a switch from data reception to data transmission. This may allow the UE to complete data reception earlier and to switch to data transmission in a timely manner. In one design, the UE may receive a first OFDM symbol and discard a first amount of cyclic prefix for the first OFDM symbol. The UE may then receive a second OFDM symbol and discard a second amount of cyclic prefix for the second OFDM symbol. The second amount of cyclic prefix to discard may be determined based on the amount of time needed to switch from data reception to data transmission, which may be dependent on the amount of time advance between transmit timing and receive timing at the UE.
    Type: Application
    Filed: September 8, 2008
    Publication date: May 14, 2009
    Applicant: QUALCOMM Incorporated
    Inventors: Juan Montojo, Durga Malladi, Shimman Patel
  • Publication number: 20090046672
    Abstract: Systems, methodologies, and devices are described that facilitate transmitting a guard time parameter to a mobile device to facilitate rate matching data around a guard time region associated with a downlink subframe of a radio frame sequence. A base station transmits the guard time parameter via PBCH or DBCH to the mobile device. The base station rate matches data associated with PDSCH, comprising DBCH, around the guard time region, and transmits PDSCH to the mobile device. The mobile device identifies the guard time parameter and rate matches at least a portion of the information received via the PDSCH around the guard time region to facilitate enhanced reception of PDSCH. Optionally, a radio frame sequence can be structured so that a subframe immediately following a subframe containing DBCH is a downlink subframe, which can be known by the mobile device a priori or based on a downlink subframe parameter.
    Type: Application
    Filed: August 13, 2008
    Publication date: February 19, 2009
    Applicant: QUALCOMM Incorporated
    Inventors: Durga Malladi, Juan Montojo
  • Publication number: 20080095106
    Abstract: Techniques for sending control information on a variable control channel are described. Different structures for mapping control information to control channel resources may be used depending on various factors such as operating configuration, the available resources for the control channel, the type(s) of control information being sent, the amount of control information being sent for each type, whether or not data is being sent, etc. In one design, at least one type of control information being sent may be determined and may comprise channel quality indicator (CQI) information, acknowledgement (ACK) information, and/or other types of control information. A structure of the control channel may be determined based on operating configuration (e.g., system configuration such as asymmetry of downlink and uplink allocations) and/or other factors. The at least one type of control information may be mapped to the resources for the control channel based on the structure.
    Type: Application
    Filed: July 23, 2007
    Publication date: April 24, 2008
    Inventors: Durga Malladi, Serge Willenegger
  • Publication number: 20080095263
    Abstract: Systems and methodologies are described that facilitate switching between various combinations of MIMO, SIMO, SISO and OFDM, LFDM and IFDM. According to various aspects, a method for a wireless communication network is provided that includes: receiving a first set of data information, wherein the first set of information comprising a first value, determining if the first value is above a threshold and transmitting an indication to switch to using a first transmission technique if determined that the first value is above the threshold.
    Type: Application
    Filed: June 28, 2007
    Publication date: April 24, 2008
    Inventors: Hao Xu, Byoung-hoon Kim, Durga Malladi
  • Publication number: 20080095109
    Abstract: A method and apparatus for a wireless communication system, using a repetition factor to determine how many times a acknowledgement should be repeated in response to receiving a first data transmission, selecting an acknowledgement transmission (ACK TX) pattern, wherein the ACK TX pattern comprises of resources information of a plurality of blocks used for transmitting the first acknowledgement, and transmitting, repeatedly, the acknowledgement according to the ACK TX pattern.
    Type: Application
    Filed: August 29, 2007
    Publication date: April 24, 2008
    Inventors: Durga Malladi, Serge Willenegger
  • Publication number: 20080095110
    Abstract: System(s) and method(s) are provided for transmitting data code symbols and control code symbols spanning disparate transmission time intervals in the uplink. Data and control symbols that overlap in time-domain within a transmission time interval are multiplexed and transmitted employing resources scheduled for data transmission, whereas data and control code symbols that are not multiplexed are transmitted in respective allocated resources. Multiplexing in conjunction with localized and distributed resource scheduling preserves the single-carrier characteristics of a single-carrier frequency division multiple access system.
    Type: Application
    Filed: August 29, 2007
    Publication date: April 24, 2008
    Inventors: Juan Montojo, Durga Malladi, Serge Willenegger
  • Publication number: 20080095108
    Abstract: Techniques for transmitting synchronization signals to assist user equipments (UEs) perform cell searches are described. In one design, a base station for a cell may generate and transmit a primary synchronization signal and a secondary synchronization signal, which may be used by the UEs for initial cell search at power up. The base station may also generate and transmit one or more beacon signals, which may be used by the UEs for neighbor cell search to detect for neighbor cells. The number of beacon signals to transmit and the set of subcarriers usable for each beacon signal may be determined based on the system bandwidth. Each beacon signal may be mapped to one subcarrier in the set of subcarriers in each beacon symbol period. This one subcarrier may be determined based on a beacon hopping pattern or a beacon code and may be dependent on a cell identifier (ID).
    Type: Application
    Filed: September 11, 2007
    Publication date: April 24, 2008
    Inventors: Durga MALLADI, Juan MONTOJO, Junyi LI
  • Publication number: 20080089286
    Abstract: Facilitating frequency hopping for single carrier, frequency division multiple access (SC-FDMA) transmission is described herein. By way of example, user data transmitted within a transmission allocation unit can be frequency shifted with respect to time based slots of the allocation unit. As a result, frequency hopping can be accomplished while preserving single carrier constraints and a low peak to average power ratio (PAPR). Furthermore, various frequency shifted mechanisms are disclosed to accomplish preservation of single carrier restraints. For example, a scheduler can select between cyclic frequency shifting, transposed frequency shifting, and multiplexing of frequency selective scheduled and frequency hopped data based on an audit of scheduled data for the transmission allocation unit. As a result, the reduction in interference achieved through frequency hopping can be combined with the low PAPR for various data allocation configurations.
    Type: Application
    Filed: July 9, 2007
    Publication date: April 17, 2008
    Inventors: Durga Malladi, Byoung-Hoon Kim
  • Publication number: 20080089312
    Abstract: In accordance an aspect, a method for a wireless communication system, determining a location in time of a sub-frame when SFN transmission for data will occur, determining a first transmission pattern and a second transmission pattern for reference signals, wherein the transmission patterns indicate the symbols and tones of a sub-frame to use for reference signals, selecting for use, between the first transmission pattern and second transmission pattern for reference signals depending on whether SFN data will be transmitted in the sub-frame, and broadcasting information about the selected transmission pattern prior to use thereof.
    Type: Application
    Filed: August 20, 2007
    Publication date: April 17, 2008
    Inventor: Durga Malladi
  • Publication number: 20080090528
    Abstract: Techniques for sending control information in a communication system are described. In an aspect, control information may be sent in a first frequency location (e.g., a first set of subcarriers) if data is not being sent and in a second frequency location (e.g., a second set of subcarriers) if data is being sent. In another aspect, control information may be processed in accordance with a first processing scheme if data is not being sent and with a second processing scheme if data is being sent. In one design of the first scheme, a CAZAC sequence may be modulated with each modulation symbol for control information to obtain a corresponding modulated CAZAC sequence, which may be sent on the first set of subcarriers. In one design of the second scheme, modulation symbols for control information may be combined with modulation symbols for data, transformed to frequency domain, and mapped to the second set of subcarriers.
    Type: Application
    Filed: July 5, 2007
    Publication date: April 17, 2008
    Inventor: Durga Malladi
  • Publication number: 20080089282
    Abstract: Systems and methods allow cell acquisition in a wireless communication system in frequency division multiple access mode of operation. Code sequences transmitted over primary synchronization channel (P-SCH) enable detection of symbol boundary, cyclic prefix duration, and indication of broadcast channel bandwidth. Sequences transmitted over secondary synchronization channel (S-SCH) afford radio frame boundary detection, cell identification, and broadcast channel bandwidth indication. Cell identification can be conveyed jointly between P-SCH and S-SCH codes. Broadcast channel sequences convey cyclic prefix timing, system bandwidth and other system information. Relay of cell acquisition information, as well as multiple-cell acquisition when wireless system operates with frequency reuse are described.
    Type: Application
    Filed: August 21, 2007
    Publication date: April 17, 2008
    Inventors: Durga Malladi, Byoung-Hoon Kim, Juan Montojo
  • Publication number: 20080070578
    Abstract: Techniques for quickly and efficiently performing handover are described. A user equipment (UE) may maintain a link with a serving cell and may communicate with this cell via the established link. The UE may have a candidate set of non-serving cells that are candidates for handover. The UE may maintain uplink synchronization with one or more non-serving cells in the candidate set, without having to maintain links with any of the non-serving cells. The UE may update uplink synchronization with the non-serving cells via an access procedure, e.g., send access probes to the non-serving cells and receive timing adjustments from these cells. One non-serving cell with which the UE has maintained uplink synchronization may be selected as a target cell for handover. The UE may then perform handover from the serving cell to the target cell, without performing uplink synchronization during the handover, which may improve handover latency and success rate.
    Type: Application
    Filed: April 24, 2007
    Publication date: March 20, 2008
    Inventors: Dino Flore, Durga Malladi, Etienne Chapponniere, Francesco Grilli
  • Publication number: 20080072269
    Abstract: Systems and methodologies are described that facilitate optimal transmission of system parameter data in a wireless communication system. According to various aspects, a broadcast channel is split into at least two portions, wherein one portion allows for transmission of static system parameter data at a first data rate, and a second portion allows for transmission of semi-static and dynamic parameter data at a second disparate data rate.
    Type: Application
    Filed: April 30, 2007
    Publication date: March 20, 2008
    Inventors: Durga Malladi, Juan Montojo
  • Publication number: 20080032630
    Abstract: Techniques for efficiently deriving uplink channel estimates without consuming much additional uplink resources are described. A user equipment (UE) may send a request for uplink resources on a request channel (REQCH) whenever the UE desires to transmit data on the uplink. The UE may send the REQCH on a set of subcarriers and from multiple antennas, e.g., send REQCH data on data subcarriers and pilot on pilot subcarriers. A node B may receive the request, estimate the complex channel gains for the pilot subcarriers based on received pilot symbols, and coherently demodulate received data symbols based on the channel gain estimates. The Node B may estimate the complex channel gains for the data subcarriers based on demodulated data symbols and derive a channel estimate for each UE antenna based on the channel gain estimates for the pilot and data subcarriers. The Node B may use the channel estimates for MIMO scheduling, subband scheduling, and rate selection.
    Type: Application
    Filed: March 17, 2007
    Publication date: February 7, 2008
    Inventors: Byoung-Hoon Kim, Durga Malladi, Hao Xu
  • Publication number: 20080025264
    Abstract: Method and apparatus for reducing interference in a wireless communication system when the source of interference is a deterministic component of the system. In one embodiment, the receiver weights the transmitters according to when the source of interference is transmitted. Further, the transmitter may employ power boosting to overcome the source of interference. In one embodiment, a W-CDMA system transmits a sync channel concurrently with physical channels, wherein the sync channel is not orthogonal to the physical channels. The receiver may cancel the sync channel when receiving control or data information. Similarly, the receiver may weight the transmissions from multiple transmitters.
    Type: Application
    Filed: September 25, 2007
    Publication date: January 31, 2008
    Applicant: QUALCOMM INCORPORATED
    Inventors: Serge Willenegger, Alkinoos Vayanos, Durga Malladi, Edward Tiedemann, Francesco Grilli, Josef Blanz
  • Publication number: 20080025246
    Abstract: Forward link transmission power to a user terminal in a wireless communications system having a plurality of beams is controlled by determining a baseline power level, Pbaseline, from a received active pilot channel signal-to-noise ratio (SNR); determining a power margin, Pmargin, from an identified interference susceptibility; determining a power level correction, Pcorrection, based on an identified packet error rate (PER); and setting Ptransmit based on Pbaseline, Pmargin, and Pcorrection. For example, Ptransmit may be set to a power level that is substantially equal to the sum of Pbaseline, Pmargin, and Pcorrection. The determination of each of Pbaseline, Pmargin, and Pcorrection may be performed in independently running control loops or processes.
    Type: Application
    Filed: July 23, 2007
    Publication date: January 31, 2008
    Applicant: QUALCOMM INCORPORATED
    Inventors: Jon Anderson, Durga Malladi, Steven Doerfler
  • Publication number: 20080002763
    Abstract: In a wireless communication system, a method for estimating a transmitted signal is disclosed. A wireless signal is received that includes a pilot channel and at least one other channel. A transmitted signal is estimated using an equalizer and the received wireless signal. The equalizer includes a filter with a plurality of taps that are adapted through use of an adaptive algorithm that uses an estimated pilot estimated from the received wireless signal. The pilot channel is transmitted in the wireless signal that included the at least one other channel. The estimated pilot is extracted and provided to the adaptive algorithm.
    Type: Application
    Filed: September 17, 2007
    Publication date: January 3, 2008
    Applicant: QUALCOMM INCORPORATED
    Inventors: Yongbin Wei, Durga Malladi, Josef Blanz