Patents by Inventor Sridhar Rajagopal

Sridhar Rajagopal 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: 20150207523
    Abstract: A low density parity check decoder is provided that includes a variable-node (VN) processing domain comprising high-bit resolution processing circuitry, a check-node (CN) processing domain comprising low-bit resolution processing circuitry lower than the high-bit resolution processing circuitry, and mapping circuitry configured to transfer a message between the VN processing domain and the CN processing domain.
    Type: Application
    Filed: January 16, 2015
    Publication date: July 23, 2015
    Inventors: Shadi Abu-Surra, Eran Pisek, Thomas Michael Henige, Sridhar Rajagopal
  • Patent number: 9077415
    Abstract: A base station is capable of communicating with a plurality of subscriber stations using a beamforming scheme that varies beams over different time instances. The base station includes a plurality of antenna arrays configured to transmit N spatial beams and carry a reference symbols corresponding to specific spatial beams. The base station also includes NRF number of radio frequency (RF) processing chains coupled to respective ones of the plurality of antenna arrays, wherein N>>NRF. The subscriber station includes MRF processing receive paths configured to receive M number of beams from the base station.
    Type: Grant
    Filed: November 16, 2012
    Date of Patent: July 7, 2015
    Assignee: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Kaushik Josiam, Shadi Abu-Surra, Ying Li, Sridhar Rajagopal, Zhouyue Pi
  • Patent number: 9032133
    Abstract: One embodiment of the present invention is a system including: (a) plural virtualization systems configured in a cluster; (b) storage accessible to each virtualization system of the cluster, wherein for each virtual machine operative in a virtualization system of the cluster, the storage maintains a representation of virtual machine state that includes at least a description of a hardware system virtualized and an image of virtualized memory state for the virtual machine; and (c) a failover system that, responsive to an interruption of, or on, a particular one of the virtualization systems, transitions at least one affected virtual machine to another virtualization system of the cluster and resumes computations of the transitioned virtual machine based on state encoded by a corresponding one of the virtual machine states represented in the storage.
    Type: Grant
    Filed: September 23, 2014
    Date of Patent: May 12, 2015
    Assignee: VMware, Inc.
    Inventors: Rene W. Schmidt, Sridhar Rajagopal
  • Patent number: 9008222
    Abstract: A station in a wireless communication system includes a processor circuitry configured to form at least a first plurality of data streams and a second plurality of data streams, and a digital precoder configured to receive the first plurality of data streams and the second plurality of data streams. The wireless station can further include a plurality of radio frequency (RF) beamforming chains connected to the digital precoder and configured to form at least one RF envelope, wherein the digital precoder is configured to steer a plurality of digital beams within the at least one RF beam envelope, the digital beams forming a plurality of spatially distinct paths for the first plurality of data streams and a plurality of spatially distinct paths for the second plurality of data streams, and a plurality of antennas operably connected to the RF beamforming chains.
    Type: Grant
    Filed: August 12, 2013
    Date of Patent: April 14, 2015
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Richard Stirling-Gallacher, Kaushik Morapakkam Josiam, Sridhar Rajagopal, Young-Han Nam
  • Publication number: 20150089272
    Abstract: Embodiments maintain high availability of software application instances in a fault domain. Subordinate hosts are monitored by a master host. The subordinate hosts publish heartbeats via a network and datastores. Based at least in part on the published heartbeats, the master host determines the status of each subordinate host, distinguishing between subordinate hosts that are entirely inoperative and subordinate hosts that are operative but partitioned (e.g., unreachable via the network). The master host may restart software application instances, such as virtual machines, that are executed by inoperative subordinate hosts or that cease executing on partitioned subordinate hosts.
    Type: Application
    Filed: December 5, 2014
    Publication date: March 26, 2015
    Applicant: VMWARE, INC.
    Inventors: Michael Nelson, Keith Farkas, Elisha Ziskind, Sridhar Rajagopal, Guoqiang Shu, Ron Passerini, Joanne Ren
  • Patent number: 8984508
    Abstract: A method for restarting a virtual machine in a virtual computing system having a plurality of hosts and a resource scheduler for the plurality of hosts includes writing a placement request for the virtual machine to a shared channel that is accessible by the resource scheduler. The method further includes reading a placement result from the shared channel, wherein the placement result is generated by the resource scheduler responsive to the placement request; and restarting the virtual machine in accordance with the placement result.
    Type: Grant
    Filed: June 2, 2011
    Date of Patent: March 17, 2015
    Assignee: VMware, Inc.
    Inventors: Guoqiang Shu, Keith Farkas, Eddie Ma, Michael Nelson, Elisha Ziskind, Sridhar Rajagopal, Minwen Ji
  • Publication number: 20150058663
    Abstract: One embodiment of the present invention is a system including: (a) plural virtualization systems configured in a cluster; (b) storage accessible to each virtualization system of the cluster, wherein for each virtual machine operative in a virtualization system of the cluster, the storage maintains a representation of virtual machine state that includes at least a description of a hardware system virtualized and an image of virtualized memory state for the virtual machine; and (c) a failover system that, responsive to an interruption of, or on, a particular one of the virtualization systems, transitions at least one affected virtual machine to another virtualization system of the cluster and resumes computations of the transitioned virtual machine based on state encoded by a corresponding one of the virtual machine states represented in the storage.
    Type: Application
    Filed: September 23, 2014
    Publication date: February 26, 2015
    Applicant: VMWARE, INC.
    Inventors: Rene W. Schmidt, Sridhar Rajagopal
  • Patent number: 8950933
    Abstract: A method, apparatus, and a non-transitory computer readable storage medium for supporting visible light communication (VLC) exchanges bitmaps for capabilities field exchange in a media access control (MAC) layer during link establishment and association with other VLC-enabled devices. An aggregation bitmap is generated to indicate whether a visible light communication (VLC) transmitter of a first device uses at least one aggregated band that comprises multiple active frequency bands. The aggregation bitmap is transmitted in a capabilities information exchange (CIE) signal to a second device. A guard bitmap that identifies a set of guard frequency bands is also generated and transmitted in the CIE signal. Each guard frequency band indicates leakage transmission from the VLC transmitter.
    Type: Grant
    Filed: September 30, 2010
    Date of Patent: February 10, 2015
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sridhar Rajagopal, Farooq Khan, Ying Li, Jaeseung Son
  • Patent number: 8929473
    Abstract: A method and apparatus enable combined baseband (BB) and radio frequency (RF) processing of signals. The method includes receiving, by a receiver, channel estimation information for a channel between a transmitter and the receiver. The method includes identifying a plurality of paths in the channel based on the channel estimation information. The method includes calculating an RF precoding matrix for precoding one or more signals to be transmitted on each of the identified paths. The RF precoding matrix includes a phase shift for each of the identified paths. Additionally, the method includes calculating a BB precoding matrix for precoding the one or more signals by a BB precoding unit associated with the transmitter.
    Type: Grant
    Filed: July 18, 2012
    Date of Patent: January 6, 2015
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Omar El Ayach, Sridhar Rajagopal, Shadi Abu-Surra, Zhouyue Pi
  • Patent number: 8924967
    Abstract: Embodiments maintain high availability of software application instances in a fault domain. Subordinate hosts are monitored by a master host. The subordinate hosts publish heartbeats via a network and datastores. Based at least in part on the published heartbeats, the master host determines the status of each subordinate host, distinguishing between subordinate hosts that are entirely inoperative and subordinate hosts that are operative but partitioned (e.g., unreachable via the network). The master host may restart software application instances, such as virtual machines, that are executed by inoperative subordinate hosts or that cease executing on partitioned subordinate hosts.
    Type: Grant
    Filed: April 28, 2011
    Date of Patent: December 30, 2014
    Assignee: VMware, Inc.
    Inventors: Michael Nelson, Keith Farkas, Elisha Ziskind, Sridhar Rajagopal, Guoqiang Shu, Ron Passerini, Joanne Ren
  • Patent number: 8913631
    Abstract: For use in visible light communication (VLC), synchronization with multiple topology support while transmitting an extended preamble includes transmitting a two-part preamble sequence. The preamble sequence includes one or more repetitions of a fast locking pattern (FLP) configured to be used clock synchronization, and one or more repetitions of a topology dependent pattern (TDP) configured to be used to distinguish a plurality of VLC topologies. The method for transmitting an extended preamble includes generating an extended preamble and transmitting the extended preamble during a receive or idle mode for maintaining visibility support and for better synchronization performance.
    Type: Grant
    Filed: February 12, 2013
    Date of Patent: December 16, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sridhar Rajagopal, Eun Tae Won, Ying Li
  • Patent number: 8880774
    Abstract: One embodiment of the present invention is a system including: (a) plural virtualization systems configured in a cluster; (b) storage accessible to each virtualization system of the cluster, wherein for each virtual machine operative in a virtualization system of the cluster, the storage maintains a representation of virtual machine state that includes at least a description of a hardware system virtualized and an image of virtualized memory state for the virtual machine; and (c) a failover system that, responsive to an interruption of, or on, a particular one of the virtualization systems, transitions at least one affected virtual machine to another virtualization system of the cluster and resumes computations of the transitioned virtual machine based on state encoded by a corresponding one of the virtual machine states represented in the storage.
    Type: Grant
    Filed: October 7, 2013
    Date of Patent: November 4, 2014
    Assignee: VMWare, Inc.
    Inventors: Rene W. Schmidt, Sridhar Rajagopal
  • Patent number: 8855496
    Abstract: A method and apparatus conduct an optical clock rate negotiation to support asymmetric clock rates for visible light communication (VLC) in a VLC device. A first frame that includes a receiver clock rate supported by a first VLC device is transmitted at a predetermined clock rate. A response frame that includes a receiver clock rate supported by a second VLC device is received from the second VLC device. A transmission clock rate of the first VLC device is selected based on the response frame from the second VLC device. Subsequent frames for data communication are transmitted to the second VLC device at the selected transmission clock rate of the first device. Alternatively, when conducting optical clock negotiation in the PHY layer, multiple clock rates are supported within a single frame.
    Type: Grant
    Filed: December 21, 2010
    Date of Patent: October 7, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sridhar Rajagopal, Eran Pisek, Farooq Khan, Ying Li
  • Patent number: 8774142
    Abstract: For use in a visible light communication (VLC) network, a system and method for communicating a plurality of medium access control (MAC) frames. The method includes providing a single frame structure to support a plurality of topologies, the plurality of topologies including peer-to-peer, broadcast, star and visibility topologies. The method also includes transmitting a plurality of frames comprising a plurality of frame types, the plurality of frame types comprising data, beacon, command, acknowledgement, and color-visibility-dimming (CVD) frames.
    Type: Grant
    Filed: September 3, 2010
    Date of Patent: July 8, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sridhar Rajagopal, Doyoung Kim, Ying Li, Farooq Khan
  • Patent number: 8731406
    Abstract: For use in a visible light communication (VLC) network, a method for generating high resolution visibility frames for visibility or dimming support. The method includes determining a required visibility for the high resolution frames. The method also includes generating a pattern that meets the determined required visibility, the pattern having a first quantity of first low resolution frames and a second quantity of second low resolution frames. The method further includes transmitting the pattern to achieve the required high resolution frames.
    Type: Grant
    Filed: April 26, 2010
    Date of Patent: May 20, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sridhar Rajagopal, Farooq Khan
  • Publication number: 20140084688
    Abstract: A method for wireless power transmission includes establishing respective wireless communication link between a coordinating transmitter and each receiver. The method further includes measuring respective mutual impedance between a coordinating transmitter and each receiver by applying a voltage to the coordinating transmitter and configuring each receiver to measure an induced current in response to the applied voltage. The method calculates respective matching impedance for the coordinating transmitter and each receiver based on corresponding mutual impedance. The method transmits the respective matching impedance to each receiver to enable each receiver to adjust to have the respective matching impedance. The method adjusts the coordinating transmitter to have the respective matching impedance.
    Type: Application
    Filed: September 16, 2013
    Publication date: March 27, 2014
    Applicant: Samsung Electronics Co. LTD
    Inventors: Ioannis Tzanidis, Umar Azad, Sridhar Rajagopal
  • Publication number: 20140050280
    Abstract: A station in a wireless communication system includes a processor circuitry configured to form at least a first plurality of data streams and a second plurality of data streams, and a digital precoder configured to receive the first plurality of data streams and the second plurality of data streams. The wireless station can further include a plurality of radio frequency (RF) beamforming chains connected to the digital precoder and configured to form at least one RF envelope, wherein the digital precoder is configured to steer a plurality of digital beams within the at least one RF beam envelope, the digital beams forming a plurality of spatially distinct paths for the first plurality of data streams and a plurality of spatially distinct paths for the second plurality of data streams, and a plurality of antennas operably connected to the RF beamforming chains.
    Type: Application
    Filed: August 12, 2013
    Publication date: February 20, 2014
    Applicant: Samsung Electronics Co., Ltd
    Inventors: Richard Stirling-Gallacher, Kaushik Morapakkam Josiam, Sridhar Rajagopal, Young-Han Nam
  • Publication number: 20140040896
    Abstract: One embodiment of the present invention is a system including: (a) plural virtualization systems configured in a cluster; (b) storage accessible to each virtualization system of the cluster, wherein for each virtual machine operative in a virtualization system of the cluster, the storage maintains a representation of virtual machine state that includes at least a description of a hardware system virtualized and an image of virtualized memory state for the virtual machine; and (c) a failover system that, responsive to an interruption of, or on, a particular one of the virtualization systems, transitions at least one affected virtual machine to another virtualization system of the cluster and resumes computations of the transitioned virtual machine based on state encoded by a corresponding one of the virtual machine states represented in the storage.
    Type: Application
    Filed: October 7, 2013
    Publication date: February 6, 2014
    Applicant: VMware, Inc.
    Inventors: Rene W. Schmidt, Sridhar Rajagopal
  • Patent number: 8620154
    Abstract: A visible light communication (VLC) device is provided for use in a VLC system. The VLC device detect a trigger condition indicating a failure of a VLC link associated with first allocated resources used to communicate with a second VLC device. In response to the detection, the VLC device terminates on the first allocated resources transmission of data to the second VLC device and transmits a fast link recovery (FLR) signal using the first allocated resources. The VLC device receives a fast link recovery response (FLR RSP) signal indicating the second VLC device received the FLR signal and, in response, the VLC device resumes transmission of data to the second VLC device.
    Type: Grant
    Filed: July 16, 2010
    Date of Patent: December 31, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Ying Li, Sridhar Rajagopal
  • Publication number: 20130336242
    Abstract: An apparatus includes a baseband signal processing block, processing circuitry, and at least one radio frequency (RF) communication module communicably coupled to the baseband signal processing block and configured to communicate using a selected mode of communication in a channel. The processing circuitry is configured to detect a sub-channel band of unavailable spectrum within the channel, the band of unavailable spectrum being less than a whole of the channel. The channel includes one contiguous band of frequencies divisible into at least two non-overlapping non-adjacent sub-channels. The processing circuitry is configured to select one mode of communication selected from a plurality of modes including: a carrier aggregation (CA) only mode, a multiple input multiple output (MIMO) only mode, and a carrier aggregation multiple input multiple output (CA-MIMO) hybrid mode.
    Type: Application
    Filed: May 21, 2013
    Publication date: December 19, 2013
    Applicant: Samsung Electronics Co., LTD
    Inventors: Sridhar Rajagopal, Richard Stirling-Gallacher, Krishna Sayana, Jianzhong Zhang, Farooq Khan