Patents by Inventor Sandeep H. Krishnamurthy

Sandeep H. Krishnamurthy 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: 8942302
    Abstract: A method and apparatus provide antenna array channel feedback. The method can include receiving, at a wireless terminal, a set of channel state information reference signals. The method can include determining, by the wireless terminal, based on the received set of channel state information reference signals, a precoding matrix that is a product of a first precoding matrix and a second precoding matrix. The first precoding matrix can have at least a representation in terms of a representation matrix. The representation matrix can be based on a matrix selected from a first codebook. The second precoding matrix can be based on a second codebook. The method can include transmitting, by the wireless terminal, a representation of at least one of the first precoding matrix and the second precoding matrix.
    Type: Grant
    Filed: December 20, 2012
    Date of Patent: January 27, 2015
    Assignee: Google Technology Holdings LLC
    Inventors: Sandeep H. Krishnamurthy, Tyler A. Brown, Colin D. Frank, Robert T. Love, Vijay Nangia
  • Publication number: 20150003275
    Abstract: A wireless communication terminal is disclosed. The terminal includes a transceiver coupled to a processor configured to determine that a subset of a plurality of resource elements (REs) must be excluded from demodulation, the plurality of REs received in a signal from a first base station, to estimate a hypothetical block error rate (BLER) based on the signal received from the first base station by excluding the subset of the plurality of REs, and to estimate channel state information based on the hypothetical BLER.
    Type: Application
    Filed: September 15, 2014
    Publication date: January 1, 2015
    Inventor: Sandeep H. Krishnamurthy
  • Publication number: 20140362938
    Abstract: Disclosed are methods for codebook sub-sampling. In various implementations, a wireless terminal receives a reference signal, determines, based on the reference signal, a first precoding index i2 for a first subband and a second precoding index i2? for a second subband. The wireless terminal transmits a representation of i2 and a representation of i2? to a base station. In various implementations, i2? belongs to the set S12 which, in one implementation, equals {mod(i2?K1+k,K), k=0, 1, . . . , K2}, where K1>1, and where K2>1 and K>1 are integers. According to an implementation, the wireless terminal receives the reference signal from a first base station and transmits the representations of i2 and i2? to a second base station.
    Type: Application
    Filed: June 2, 2014
    Publication date: December 11, 2014
    Applicant: MOTOROLA MOBILITY LLC
    Inventors: Sandeep H. Krishnamurthy, Tyler A. Brown, Robert T. Love, Vijay Nangia
  • Patent number: 8868123
    Abstract: The present disclosure sets forth multiple embodiments of the invention. Among those embodiments is a method for managing the power of an uplink signal (e.g., an LTE PUSCH or PUCCH). The method involves determining a convolution of a first function and a second function (which may be power density functions) of the uplink signal and determining the power of the uplink signal based on the convolution. The uplink signal comprises one or both of a data signal (transmitted over a PUSCH, for example) and a control signal (transmitted over a PUSCH or PUCCH, for example). The uplink signal is transmitted over one or more subcarriers (which may be carried by resource blocks, for example).
    Type: Grant
    Filed: July 16, 2012
    Date of Patent: October 21, 2014
    Assignee: Motorola Mobility LLC
    Inventors: Colin D. Frank, Sandeep H. Krishnamurthy, Tyler A. Brown
  • Publication number: 20140302855
    Abstract: This disclosure sets forth methods and devices for communication between mobile devices and base stations with active and dormant states. In an embodiment, a base station transmits system information during an active state of the base station with at least one system-information message. The at least one system-information message includes a SystemInformationBlockType1 (“SIB1”) message with a first update-indicator field. The base station selects an update value that indicates whether the system information has changed since a previous transmission of a previous SIB1 message. The base station transmits at least one dormant-state message during a dormant state of the base station with the selected update value in a second update-indicator field of the at least one dormant-state message.
    Type: Application
    Filed: April 2, 2014
    Publication date: October 9, 2014
    Applicant: MOTOROLA MOBILITY LLC
    Inventors: Ravikiran Nory, Sandeep H. Krishnamurthy, Ravi Kuchibhotla, Robert T. Love, Vijay Nangia, Ajit Nimbalker
  • Publication number: 20140302856
    Abstract: This disclosure sets forth methods and devices for communication between mobile devices and base stations with active and dormant states. In an embodiment, a base station transmits system information during an active state of the base station with at least one system-information message. The at least one system-information message includes a SystemInformationBlockType1 (“SIB1”) message with a first update-indicator field. The base station selects an update value that indicates whether the system information has changed since a previous transmission of a previous SIB1 message. The base station transmits at least one dormant-state message during a dormant state of the base station with the selected update value in a second update-indicator field of the at least one dormant-state message.
    Type: Application
    Filed: April 2, 2014
    Publication date: October 9, 2014
    Applicant: MOTOROLA MOBILITY LLC
    Inventors: Ravikiran Nory, Sandeep H. Krishnamurthy, Ravi Kuchibhotla, Robert T. Love, Vijay Nangia, Ajit Nimbalker
  • Patent number: 8837301
    Abstract: A wireless communication terminal is disclose. The terminal includes a transceiver coupled to a processor configured to determine that a subset of a plurality of REs must be excluded from demodulation, the plurality of resource elements (REs) received in a signal from a first base station, to estimate a hypothetical block error rate (BLER) based on the signal received from the first base station by excluding the subset of the plurality of Res, and to estimate channel state information based on the hypothetical block error rate (BLER).
    Type: Grant
    Filed: November 2, 2011
    Date of Patent: September 16, 2014
    Assignee: Motorola Mobility LLC
    Inventor: Sandeep H. Krishnamurthy
  • Publication number: 20140254508
    Abstract: A wireless terminal is capable of receiving a pilot signal from a base station; and determining a precoding matrix as a linear combination of two matrices V1 and V2 based on the received pilot signal. In one implementation, the two matrices V1 and V2 are sub-matrices of a matrix U of a codebook, the linear combination is u:=(V1+?V2)/?{square root over (1+|?|2)} and ? is one of a real-valued number and a complex-valued number. The wireless terminal is also capable of transmitting a representation of at least a portion of the precoding matrix to the base station.
    Type: Application
    Filed: December 26, 2013
    Publication date: September 11, 2014
    Applicant: MOTOROLA MOBILITY LLC
    Inventors: Sandeep H. Krishnamurthy, Tyler A. Brown, Colin D. Frank, Robert T. Love, Vijay Nangia
  • Publication number: 20140198765
    Abstract: Various methods for controlling an aggressor user equipment (UE) can use two transmission power control loops to mitigate UE-to-UE adjacent carrier frequency band interference to a geographically proximal victim UE. The aggressor UE can select between different transmission power parameters based on two (or more) power values. The usage of any particular power value depends on the time period of the transmission. For example, if a proximal victim UE is scheduled to receive when the aggressor UE is scheduled to transmit, a lower power value may be selected as instructed by a co-scheduler or determined by the aggressor UE. The aggressor UE can also send dual power headroom reports to its serving base station based on the two power values.
    Type: Application
    Filed: March 14, 2014
    Publication date: July 17, 2014
    Applicant: Motorola Mobility LLC
    Inventors: Sandeep H. Krishnamurthy, Robert T. Love, Ajit Nimbalker, Ravikiran Nory, Kenneth A. Stewart
  • Patent number: 8767708
    Abstract: The cell searcher module (CSM) of a wireless communication device detects that the device is in coverage region of an eNB by processing received signal associated with the primary synchronization (PSCH) and secondary synchronization (SSCH) sequences transmitted by the eNB. The wireless device determines whether candidate SCH signals from candidate neighbor cells are synchronous with SCH sequences from the serving cell by implementing one of three methods. In a first method, the CSM generates a joint estimate of the received power of SSCH sequences corresponding to already detected/identified serving cell and a hypothetical neighbor cell. In a second method, the CSM re-constructs SCH sequences corresponding to already detected cells and subtracts the re-constructed SCH sequences from the received signal to obtain a residual signal with reduced serving cell interference. In a third embodiment, the CSM performs a correlation of estimated channel responses to determine whether the neighbor cell is present.
    Type: Grant
    Filed: December 30, 2010
    Date of Patent: July 1, 2014
    Assignee: Motorola Mobility LLC
    Inventors: Sandeep H. Krishnamurthy, Colin D. Frank
  • Publication number: 20140177683
    Abstract: A method and apparatus provide antenna array channel feedback. The method can include receiving, at a wireless terminal, a set of channel state information reference signals. The method can include determining, by the wireless terminal, based on the received set of channel state information reference signals, a precoding matrix that is a product of a first precoding matrix and a second precoding matrix. The first precoding matrix can have at least a representation in terms of a representation matrix. The representation matrix can be based on a matrix selected from a first codebook. The second precoding matrix can be based on a second codebook. The method can include transmitting, by the wireless terminal, a representation of at least one of the first precoding matrix and the second precoding matrix.
    Type: Application
    Filed: December 20, 2012
    Publication date: June 26, 2014
    Applicant: MOTOROLA MOBILITY LLC
    Inventors: Sandeep H. Krishnamurthy, Tyler A. Brown, Colin D. Frank, Robert T. Love, Vijay Nangia
  • Publication number: 20140177745
    Abstract: A method and apparatus provide antenna array channel feedback. The method can include receiving a first set of channel state information reference signals on resource elements, and a second set of channel state information reference signals on resource elements. The method can include determining a first precoding matrix based on the received first set of channel state information reference signals. The first precoding matrix can be chosen from a first codebook. The method can include determining a second precoding matrix based on the second set of channel state information reference signals. The second precoding matrix can be chosen from a second codebook that is different than the first codebook. The method can include transmitting a representation of at least one of the first precoding matrix and the second precoding matrix.
    Type: Application
    Filed: December 20, 2012
    Publication date: June 26, 2014
    Applicant: MOTOROLA MOBILITY LLC
    Inventors: Sandeep H. Krishnamurthy, Tyler A. Brown, Colin D. Frank, Robert T. Love, Vijay Nangia
  • Publication number: 20140177744
    Abstract: A method and apparatus provide antenna array channel feedback. The method can include receiving, at a wireless terminal, a set of channel state information reference signals. The method can include determining a precoding matrix based on the received set of channel state information reference signals. The precoding matrix can have a representation in terms of three components. The first component of the three components can be determined from a first set of vectors. The second component of the three components can be determined from a first set of parameters. The third component of the three components can be determined from a second set of parameters. The second set of parameters can be a set of unit-magnitude scalars. The method can include transmitting, by the wireless terminal, a representation of at least one of the first component, the second component, and the third component.
    Type: Application
    Filed: December 20, 2012
    Publication date: June 26, 2014
    Applicant: MOTOROLA MOBILITY LLC
    Inventors: Sandeep H. Krishnamurthy, Tyler A. Brown, Colin D. Frank, Robert T. Love, Vijay Nangia
  • Patent number: 8737330
    Abstract: A method in a wireless communication device comprises determining transmission powers for at least two clusters, wherein each cluster includes at least one physical resource block (RB), determining a difference in a characteristic of the transmission powers determined for the at least two clusters, and varying a transmit power allocated to at least one cluster if the difference in the characteristic exceeds a power spread threshold, wherein the power allocated to each cluster is a function of pathloss between the wireless communication device and a serving base station.
    Type: Grant
    Filed: June 24, 2011
    Date of Patent: May 27, 2014
    Assignee: Motorola Mobility LLC
    Inventors: Sandeep H. Krishnamurthy, Colin D. Frank, Vijay Nangia
  • Patent number: 8730925
    Abstract: A base station communicates a positioning reference signal (PRS) to wireless communication devices over a downlink in a wireless communication system by encoding a PRS into a first set of transmission resources, encoding other information into a second set of transmission resources, multiplexing the two sets of resources into a subframe such that the first set of resources is multiplexed into at least a portion of a first set of orthogonal frequency division multiplexed (OFDM) symbols based on an identifier associated with the base station and the second set of resources is multiplexed into a second set of OFDM symbols. Upon receiving the subframe, a wireless communication device determines which set of transmission resources contains the PRS based on the identifier associated with the base station that transmitted the subframe and processes the set of resources containing the PRS to estimate timing (e.g., time of arrival) information.
    Type: Grant
    Filed: April 8, 2010
    Date of Patent: May 20, 2014
    Assignee: Motorola Mobility LLC
    Inventors: Colin D. Frank, Sandeep H. Krishnamurthy, Kenneth A. Stewart, Xiangyang Zhuang, Robert T. Love
  • Publication number: 20140133462
    Abstract: A method (700, 800) and apparatus (500, 600) for distinguishing cells with the same physical cell identifier is disclosed. The method can include receiving (820) a handover request message including target cell timing offset information at a potential target cell base station, where the potential target cell base station can have a physical cell identifier. The method can include comparing (830) the received target cell timing offset information with stored timing offset information at the potential target cell base station. The method can include sending (840) a handover request accept message if the received target cell timing offset information is substantially equal to the stored timing offset information. The method can also include receiving (720), at a wireless terminal, a target cell physical cell identifier and determining (730) a target cell timing offset of a radio frame of the target cell with respect to reference timing of a serving cell.
    Type: Application
    Filed: January 22, 2014
    Publication date: May 15, 2014
    Applicant: MOTOROLA MOBILITY LLC
    Inventors: Murali Narasimha, Sandeep H. Krishnamurthy, Ravi Kuchibhotla
  • Patent number: 8724492
    Abstract: A method and apparatus for a co-scheduler can mitigate UE-to-UE adjacent carrier frequency band interference by allocating three sets to a first user equipment uplink. Each set has at least one sub-carrier in a first frequency band, at least one uplink time period, and at least one transmission power parameter. The co-scheduler initially allocates the first set. The co-scheduler allocates the second set in response to detecting a second user equipment operating proximal to the first user equipment, and the second set differs from the first set in either at least one sub-carrier or at least one transmission power parameter. The co-scheduler allocates the third set in response to detecting that the second user equipment is no longer operating proximal to the first user equipment, and the third set differs from the second set in either at least one sub-carrier or at least one transmission power parameter.
    Type: Grant
    Filed: April 8, 2011
    Date of Patent: May 13, 2014
    Assignee: Motorola Mobility LLC
    Inventors: Colin D Frank, Sandeep H Krishnamurthy, Robert T Love, Ajit Nimbalker, Ravikiran Nory, Kenneth A Stewart
  • Publication number: 20140126440
    Abstract: The present disclosure sets forth multiple embodiments of the invention. Among those embodiments is a method for determining a maximum power reduction of an uplink signal. The uplink signal is transmitted on a carrier that has a range of frequencies. Frequencies outside of the carrier frequency range include adjacent channel regions. Resource blocks of the carrier that have been allocated for use by to transmit the uplink signal are identified. A power spectral density is determined based on the identified resource blocks. A metric that is based on a third order convolution of the power spectral density function is determined. A maximum power reduction for the adjacent channel regions is also determined based on the metric.
    Type: Application
    Filed: November 5, 2012
    Publication date: May 8, 2014
    Applicant: MOTOROLA MOBILITY LLC
    Inventors: Colin D. Frank, Tyler A. Brown, Sandeep H. Krishnamurthy
  • Publication number: 20140071944
    Abstract: A method (700, 800) and apparatus (500, 600) for distinguishing cells with the same physical cell identifier is disclosed. The method can include receiving (820) a handover request message including target cell timing offset information at a potential target cell base station, where the potential target cell base station can have a physical cell identifier. The method can include comparing (830) the received target cell timing offset information with stored timing offset information at the potential target cell base station. The method can include sending (840) a handover request accept message if the received target cell timing offset information is substantially equal to the stored timing offset information. The method can also include receiving (720), at a wireless terminal, a target cell physical cell identifier and determining (730) a target cell timing offset of a radio frame of the target cell with respect to reference timing of a serving cell.
    Type: Application
    Filed: November 11, 2013
    Publication date: March 13, 2014
    Applicant: MOTOROLA MOBILITY LLC
    Inventors: Murali Narasimha, Sandeep H. Krishnamurthy, Ravi Kuchibhotla
  • Publication number: 20140064109
    Abstract: A wireless device transmits downlink interference-related information to a transmission point. The wireless device generates this information by listening to reference signals associated with a first reference signal resource as well as with a second reference signal resource. The wireless device uses these reference signals to estimate a first channel matrix relating to the first reference signal resource and a second channel matrix relating to the second reference signal resource. Using the estimated first and second channel matrices, the wireless device derives a pair of precoding matrices. Precoding matrix indicators representing the precoding matrix pair are sent to the transmission point.
    Type: Application
    Filed: August 31, 2012
    Publication date: March 6, 2014
    Applicant: MOTOROLA MOBILITY LLC
    Inventor: Sandeep H. Krishnamurthy