Patents by Inventor Rohit U. Nabar

Rohit U. Nabar 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: 10181881
    Abstract: Systems, apparatuses, and techniques relating to wireless local area network devices are described. A described technique includes transmitting a sounding packet to wireless communication devices; receiving, in response to the sounding packet, feedback packets from the wireless communication devices, wherein the feedback packets collectively comprise beamforming feedback, the beamforming feedback being derived from received versions of the sounding packet; determining a steering matrix based on the beamforming feedback; and transmitting, within a frame, spatially steered data packets to the wireless communications devices. The spatially steered data packets can be based on the steering matrix and data streams intended respectively for the wireless communication devices. The spatially steered data packets can concurrently provide the data streams respectively within the frame to the wireless communication devices via different spatial wireless channels.
    Type: Grant
    Filed: February 19, 2016
    Date of Patent: January 15, 2019
    Assignee: Marvell World Trade Ltd.
    Inventors: Hongyuan Zhang, Hui-Ling Lou, Rohit U. Nabar, Yong Liu
  • Patent number: 10141997
    Abstract: One or more beamsteering matrices are applied to one or more signals to be transmitted via multiple antennas. After the one or more beamsteering matrices are applied to the one or more signals, the plurality of signals is provided to a plurality of power amplifiers coupled to the multiple antennas. Signal energies are determined for the plurality of signals provided to the plurality of power amplifiers, and relative signal energies are determined based on the determined signal energies. Output power levels of the plurality of power amplifiers are adjusted based on the determined relative signal energies.
    Type: Grant
    Filed: November 28, 2016
    Date of Patent: November 27, 2018
    Assignee: Marvell World Trade Ltd.
    Inventors: Rohit U. Nabar, Hongyuan Zhang
  • Patent number: 10135572
    Abstract: In a method for generating a data unit conforming to a first communication protocol, a first field and a second field to be included in a preamble of the data unit are generated. The first field includes a first set of one or more information bits that indicate a duration of the data unit and is formatted such that the first field allows a receiver device that conforms to a second communication protocol to determine the duration of the data unit. The second field includes a second set of one or more information bits that indicate to a receiver device that conforms to the first communication protocol that the data unit conforms to the first communication protocol. The first field and the second field are modulated using a modulation scheme specified for a field corresponding to the first field and the second field, respectively, by the second communication protocol.
    Type: Grant
    Filed: September 4, 2015
    Date of Patent: November 20, 2018
    Assignee: Marvell World Trade Ltd.
    Inventors: Hongyuan Zhang, Sudhir Srinivasa, Rohit U. Nabar, Raja Banerjea
  • Patent number: 10070482
    Abstract: A preamble, a first portion of a data payload, a midamble, and a second portion of the data payload of a single data unit are generated. The midamble is to be transmitted subsequent to transmission of the first portion of the data payload and prior to transmission of the second portion of the data payload. The midamble includes an indication of at least one characteristic of the data payload such as an indication of a size of the second portion of the data payload, or whether or not the data payload includes one or more other portions in addition to the first and second portions. A network interface of a communication device is configured to generate the preamble, the first and second portions of the data payload, and the midamble.
    Type: Grant
    Filed: July 10, 2017
    Date of Patent: September 4, 2018
    Assignee: Marvell International Ltd.
    Inventors: Hongyuan Zhang, Rohit U. Nabar, Sudhir Srinivasa, Raja Banerjea, Yong Liu
  • Patent number: 10003432
    Abstract: A modulation coding scheme (MCS) is selected i) from a first set of MCSs when the PHY data unit is to be transmitted using a first channel bandwidth, and ii) from a second set of MCSs when the PHY data unit is to be transmitted using a second channel bandwidth. The first set of MCSs corresponds to i) a number of spatial streams, and ii) the first channel bandwidth, the second set of MCSs corresponds to i) the number of spatial streams, and ii) the second channel bandwidth. The second set of MCSs excludes one or more MCSs in the first set of MCSs that will result in a padding-related constraint not being met when the second channel bandwidth is to be used. Information bits are encoded according to the selected MCS, and modulated according to the selected MCS.
    Type: Grant
    Filed: August 8, 2016
    Date of Patent: June 19, 2018
    Assignee: Marvell World Trade Ltd.
    Inventors: Sudhir Srinivasa, Hongyuan Zhang, Rohit U. Nabar
  • Patent number: 9999009
    Abstract: A synchronization data unit is generated by an access point. The synchronization data unit is for scheduling subsequent simultaneous transmission of a plurality of data units by multiple communication devices. An estimate of a MIMO communication channel is generated using a plurality of training fields included in a first portion of a signal, wherein the signal corresponds to the plurality of data units transmitted simultaneously from the respective communication devices via respective sets of sets of spatial streams. Data in a second portion of the signal is decoded using the estimate of the MIMO communication channel, wherein the data in the second portion of the signal corresponds to data included in the plurality of data units.
    Type: Grant
    Filed: January 11, 2016
    Date of Patent: June 12, 2018
    Assignee: Marvell International Ltd.
    Inventors: Hongyuan Zhang, Rohit U. Nabar, Sudhir Srinivasa
  • Patent number: 9998950
    Abstract: In a method for generating a physical layer (PHY) data unit for transmission via a communication channel, the PHY data unit is generated according to a first PHY format when the PHY data unit is to be transmitted in a regular mode, wherein the first PHY format corresponds to a first bandwidth. The PHY data unit is generated according to a second PHY format when the PHY data unit is to be transmitted in an extended range mode, wherein the second PHY format corresponds to a second bandwidth. A preamble of the PHY data unit is modulated such that a receiving device can auto-detect whether the PHY data unit was transmitted at the first bandwidth or the second bandwidth.
    Type: Grant
    Filed: October 20, 2014
    Date of Patent: June 12, 2018
    Assignee: Marvell World Trade Ltd.
    Inventors: Hongyuan Zhang, Rohit U. Nabar, Raja Banerjea, Yong Liu
  • Patent number: 9948365
    Abstract: A first communication device determines that a second communication device is capable of using a transparent implicit beamforming technique to determine steering matrices for transmitting to the first communication device via a forward multiple input multiple output (MIMO) communication channel. In response to determining that the second communication device is capable of using the transparent implicit beamforming technique, the first communication device transmits at least a certain number of data units to the second communication device using a maximum number of spatial streams during a time period of a certain duration when the first communication device is otherwise using less than the maximum number of spatial streams to transmit other data units to the second communication device. Transmitting the certain number of data units using the maximum number of spatial streams permits the second communication device to use the transparent implicit beamforming technique to develop one or more steering matrices.
    Type: Grant
    Filed: August 21, 2017
    Date of Patent: April 17, 2018
    Assignee: Marvell World Trade Ltd.
    Inventors: Rohit U. Nabar, Hongyuan Zhang, Sudhir Srinivasa, Xiayu Zheng
  • Patent number: 9941988
    Abstract: Systems and techniques relating to wireless devices are described. A described system includes a first radio unit configured to receive communication signals that include one or more signals indicative of a first physical layer frame of a data packet, and produce a first output based on the first physical layer frame; a second radio unit configured to receive communication signals that include one or more signals indicative of a second physical layer frame of the data packet, and produce a second output based on the second physical layer frame, the one or more signals indicative of the first physical layer frame are concurrently received with the one or more signals indicative of the second physical layer frame; a deparser configured to combine outputs, including the first and second outputs, to produce a combined output; and a controller configured to resolve the data packet based on the combined output.
    Type: Grant
    Filed: July 7, 2014
    Date of Patent: April 10, 2018
    Assignee: Marvell International Ltd.
    Inventors: Hongyuan Zhang, Hui-Ling Lou, Rohit U. Nabar
  • Patent number: 9941982
    Abstract: Systems and techniques relating to beamforming testing for wireless communication are described. A described technique includes controlling a first wireless device to deactivate or activate a beamforming mode, the first device being configured to selectively use the beamforming mode to transmit data over multiple antennas; causing the first device to send a first portion of data traffic to a second wireless device via a wireless channel while the beamforming mode is deactivated; measuring first throughput values of the first portion of data traffic while the beamforming mode is deactivated; causing the first device to send a second portion of data traffic to the second device via the wireless channel while the beamforming mode is activated; measuring second throughput values of the second portion of the data traffic while the beamforming mode is activated; and producing a test result based on a comparison of the first and second throughput values, and predetermined criteria.
    Type: Grant
    Filed: April 1, 2014
    Date of Patent: April 10, 2018
    Assignee: Marvell World Trade Ltd.
    Inventors: Hongyuan Zhang, Sudhir Srinivasa, Xiayu Zheng, Rohit U. Nabar
  • Patent number: 9924512
    Abstract: A plurality of different orthogonal frequency division multiplexing (OFDM) sub-channel blocks are assigned to a plurality of devices including a first device and a second device. The plurality of OFDM sub-channel blocks includes a first OFDM sub-channel block assigned to the first device and a second OFDM sub-channel block assigned to the second device. Data for the first device and data for the second device are received. OFDM data units are generated, wherein data for the first device is modulated on sub-channels in the first OFDM sub-channel block and data for the second device is modulated on sub-channels in the second OFDM sub-channel block. At least one of the OFDM sub-channel blocks is formatted to substantially conform to a physical layer specification of a WLAN communication protocol having a maximum channel bandwidth smaller than a bandwidth of the generated OFDM data units.
    Type: Grant
    Filed: March 24, 2010
    Date of Patent: March 20, 2018
    Assignee: Marvell International Ltd.
    Inventors: Hongyuan Zhang, Rohit U. Nabar, Hui-Ling Lou
  • Publication number: 20170346536
    Abstract: A first communication device determines that a second communication device is capable of using a transparent implicit beamforming technique to determine steering matrices for transmitting to the first communication device via a forward multiple input multiple output (MIMO) communication channel. In response to determining that the second communication device is capable of using the transparent implicit beamforming technique, the first communication device transmits at least a certain number of data units to the second communication device using a maximum number of spatial streams during a time period of a certain duration when the first communication device is otherwise using less than the maximum number of spatial streams to transmit other data units to the second communication device. Transmitting the certain number of data units using the maximum number of spatial streams permits the second communication device to use the transparent implicit beamforming technique to develop one or more steering matrices.
    Type: Application
    Filed: August 21, 2017
    Publication date: November 30, 2017
    Inventors: Rohit U. NABAR, Hongyuan ZHANG, Sudhir SRINIVASA, Xiayu ZHENG
  • Patent number: 9780857
    Abstract: Systems, methods, and other embodiments associated with a hybrid beamforming architecture are described. According to one embodiment, an apparatus comprises a beamforming architecture including a baseband unit and a processor. The beamforming architecture is configured to determine a steering matrix based on at least the baseband unit and the processor; and wherein the beamforming architecture is configured to simultaneously support a plurality of beamformee client devices, each beamformee client device beamformed by a beamformer with at least one of a beamformer hardware mode and a beamformer software mode and with at least one of a beamformer explicit mode and a beamformer implicit mode.
    Type: Grant
    Filed: June 13, 2016
    Date of Patent: October 3, 2017
    Assignee: MARVELL INTERNATIONAL LTD.
    Inventors: Ying-Cheng Lee, Timothy J. Donovan, Dharmesh B. Bhagatwala, Ken Kinwah Ho, Hongyuan Zhang, Rohit U. Nabar, Tsunglun Yu
  • Publication number: 20170250785
    Abstract: A preamble of a physical layer (PHY) data unit that conforms to a first communication protocol is generated. The preamble includes a legacy field that is formatted according to a second communication protocol, and a signal field having a first orthogonal frequency division multiplexing (OFDM) symbol and a second OFDM symbol. The first OFDM symbol (i) immediately follows the legacy field and (ii) is modulated using binary phase shift keying (BPSK) modulation, whereas a third communication protocol specifies that an OFDM symbol, defined by the third communication protocol, that immediately follows the legacy field is modulated using BPSK modulation rotated by 90 degrees (Q-BPSK). The second OFDM symbol (i) immediately follows the first OFDM symbol and (ii) is modulated using Q-BPSK to indicate to a receiver device that conforms to the first communication protocol that the data unit conforms to the first communication protocol.
    Type: Application
    Filed: May 15, 2017
    Publication date: August 31, 2017
    Inventors: Hongyuan ZHANG, Hui-Ling LOU, Rohit U. NABAR, Sudhir SRINIVASA, Mao YU, Raja BANERJEA
  • Patent number: 9749022
    Abstract: In a system having a first communication device with a first plurality of radio-frequency (RF) chains coupled to a first plurality of antennas and a second communication device with a second plurality of RF chains coupled to a second plurality of antennas, the second communication device receives consecutive training packets that were transmitted by the first communication device, the consecutive training packets having been produced at the first communication device by a power level rule to the first plurality of RF chains. The second communication device determines respective channel measurements corresponding to the consecutive training packets based on the power level rule, and selects a transmit parameter based on the respective channel measurements, the transmit parameter to be used by the first communication device when transmitting to the second communication device. The second communication device transmits and indication of the selected transmit parameter to the first communication device.
    Type: Grant
    Filed: June 11, 2014
    Date of Patent: August 29, 2017
    Assignee: Marvell World Trade Ltd.
    Inventors: Hongyuan Zhang, Rohit U. Nabar, Peter Loc
  • Patent number: 9742476
    Abstract: In a method for beamforming in a multiple input multiple output (MIMO) communication system, a data unit is received from a communication device via a MIMO communication channel, and it is determined whether the data unit satisfies one or more selection criteria. Further, when it is determined that the data unit satisfies the one or more selection criteria, the data unit is selected to be used in developing a steering matrix for transmitting data units to the communication device.
    Type: Grant
    Filed: April 8, 2016
    Date of Patent: August 22, 2017
    Assignee: MARVELL WORLD TRADE, LTD.
    Inventors: Rohit U. Nabar, Hongyuan Zhang, Sudhir Srinivasa, Xiayu Zheng
  • Patent number: 9712215
    Abstract: A system and method of beamforming may reduce feedback requirements. In some implementations, a beamforming technique may employ a diagonal matrix as a beamforming matrix. In some antenna phase beamforming strategies, a diagonal beamforming matrix in which the diagonal elements have a constant magnitude may be employed. Accordingly, a beamforming system may be utilized with few feedback information bits being transmitted from the beamformee; such a system may also minimize or eliminate power fluctuations among multiple transmit antennae.
    Type: Grant
    Filed: December 28, 2012
    Date of Patent: July 18, 2017
    Assignee: Marvell International Ltd.
    Inventors: Jungwon Lee, Rohit U. Nabar, Hui-Ling Lou
  • Patent number: 9706599
    Abstract: A preamble, a first portion of a data payload, a midamble, and a second portion of the data payload of a single data unit are generated. The midamble is to be transmitted subsequent to transmission of the first portion of the data payload and prior to transmission of the second portion of the data payload. The midamble includes an indication of at least one characteristic of the data payload such as an indication of a size of the second portion of the data payload, or whether or not the data payload includes one or more other portions in addition to the first and second portions. A network interface of a communication device is configured to generate the preamble, the first and second portions of the data payload, and the midamble.
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: July 11, 2017
    Assignee: Marvell International Ltd.
    Inventors: Hongyuan Zhang, Rohit U. Nabar, Sudhir Srinivasa, Raja Banerjea, Yong Liu
  • Publication number: 20170187436
    Abstract: In one or more aspects data packets are transmitted to a receiver using predefined spatial mapping matrices, a quality of reception is received from the receiver for each of the predefined spatial mapping matrices, and one of the predefined spatial mapping matrices is selected for transmitting additional data packets to the receiver based on a highest quality of reception.
    Type: Application
    Filed: March 13, 2017
    Publication date: June 29, 2017
    Applicant: Marvell World Trade Ltd.
    Inventors: Hongyuan Zhang, Rohit U. Nabar
  • Patent number: 9673875
    Abstract: A first device including a receiver, a steering module, and a transmitter. The receiver receives a first signal transmitted using a first modulation scheme from a second device. The steering module obtains a steering matrix from the first signal transmitted using the first modulation scheme from the second device. The transmitter transmits a second signal using a second modulation scheme to the second device by reusing the steering matrix obtained from the first signal transmitted using the first modulation scheme from the second device. The first modulation scheme and the second modulation scheme are selected from a plurality of orthogonal frequency division multiplexing based modulation schemes. The second modulation scheme is different from the first modulation scheme.
    Type: Grant
    Filed: February 24, 2016
    Date of Patent: June 6, 2017
    Assignee: Marvell International LTD.
    Inventors: Hongyuan Zhang, Rohit U. Nabar, Sudhir Srinivasa