Patents by Inventor Sudhir Srinivasa

Sudhir Srinivasa 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: 10848288
    Abstract: A first communication device prompts a plurality of second communication devices to transmit, during a contiguous time period reserved for a range measurement exchange, respective first null data packets (NDPs) at respective times. The first communication device receives first NDPs from at least some of the second communication devices during the contiguous time period, and transmits one or more second NDPs to the plurality of second communication devices. The first communication device uses reception of the first NDPs and transmission of the one or more second NDPs to determine respective ranges between the first communication device and respective second communication devices.
    Type: Grant
    Filed: August 3, 2018
    Date of Patent: November 24, 2020
    Assignee: NXP USA, INC.
    Inventors: Liwen Chu, Hongyuan Zhang, Christian R. Berger, Niranjan Grandhe, Sudhir Srinivasa, Hui-Ling Lou
  • Publication number: 20200367102
    Abstract: Some embodiments described herein provide a method for transmitting a preamble in accordance with a wireless local area network communication protocol. In some embodiments, a data frame may be obtained for transmission including a preamble compliant with the wireless local area network communication protocol. It may be determined that the preamble includes a first preamble portion that spans multiple symbol durations and a second preamble portion that spans a single symbol duration. The first preamble portion via beamforming may be transmitted based on a first beamforming matrix. When a transmission mode of the second preamble portion is beamforming, a second beamforming matrix may be generated based on the first beamforming matrix, each tone for the second preamble portion may be calculated based on the second beamforming matrix. Each calculated tone may be transmitted in accordance with the wireless local area network communication protocol.
    Type: Application
    Filed: July 27, 2020
    Publication date: November 19, 2020
    Inventors: Yakun Sun, Hongyuan Zhang, Sudhir Srinivasa, Xiayu Zheng
  • Publication number: 20200329519
    Abstract: A first aggregated MAC protocol data unit (A-MPDU) is generated for transmission over a first frequency segment of a communication channel, and a second A-MPDU is generated for transmission over a second frequency segment of the communication channel. A PHY protocol data unit (PPDU) is generated to include the plurality of A-MPDUs and a second PPDU is generated to include the second A-MPDU. A first transmit processor generates a first RF signal for transmission of the first PPDU over the first frequency segment and a second transmit processor generates a second RF signal for transmission of the second PPDU over the second frequency segment. The first RF signal is transmitted in the first frequency segment simultaneously with the second RF signal being transmitted in the second frequency segment.
    Type: Application
    Filed: April 13, 2020
    Publication date: October 15, 2020
    Inventors: Rui CAO, Hongyuan ZHANG, Sudhir SRINIVASA
  • Patent number: 10805892
    Abstract: A method for communication includes respectively associating each of a plurality of client stations (STAs) with at least one basic service set (BSS) of at least one access point (AP) in a WLAN. The APs in the WLAN are synchronized prior to transmitting data to the STAs. First and second groups of the antennas are defined for downlink communication with the first and second STAs, each of the groups including antennas belonging to at least two of the APs. Different, first and second distributed beamforming parameters are computed over the first and second groups of the antennas. Respective data for transmission to the first and second STAs are distributed to the APs to which the antennas in the respective first and second groups belong and are transmitted in synchronization in accordance with the first and second distributed beamforming parameters.
    Type: Grant
    Filed: July 15, 2019
    Date of Patent: October 13, 2020
    Assignee: NXP USA, Inc.
    Inventors: B Hari Ram, Sri Varsha Rottela, Vijay Ahirwar, Sudhir Srinivasa, Nilesh N Khude
  • Patent number: 10804945
    Abstract: The present disclosure describes apparatuses and methods for dynamic interference cancellation in wireless receivers. In some aspects, a signal vector transmitted through a wireless environment is received via multiple antennas of a receiver, the signal vector affected by interfering signals in the wireless environment. The receiver determines an interference channel matrix for the signal vector based on the interference received with the signal vector and selects, from the interference channel matrix, columns of the interference channel matrix to form a noise-cancelling equalization matrix. The receiver then equalizes the signal vector with the noise-cancelling equalization matrix to remove a portion of interference from the signal vector to provide noise-cancelled equalized values of the signal vector for decoding. By so doing, the receiver may reduce effects of interference of the wireless environment (e.g.
    Type: Grant
    Filed: October 31, 2018
    Date of Patent: October 13, 2020
    Assignee: NXP USA, Inc.
    Inventors: B Hari Ram, Lokesh Sundaramurthy Satrasala, Sudhir Srinivasa, Hongyuan Zhang
  • Patent number: 10790937
    Abstract: A first communication device generates and transmits a first physical layer (PHY) data unit as part of a hybrid automatic repeat request (HARQ) session, the first PHY data unit having a first plurality of media access control (MAC) protocol data units (MPDUs) including a first MPDU. The first communication device determines that a second communication device did not acknowledge successfully receiving the first MPDU. The first communication device generates and transmits a second PHY data unit as part of the HARQ session, the second PHY data unit having a second plurality of MPDUs, the second plurality of MPDUs including the first MPDU.
    Type: Grant
    Filed: January 22, 2018
    Date of Patent: September 29, 2020
    Assignee: NXP USA, Inc.
    Inventors: Yakun Sun, Liwen Chu, Hongyuan Zhang, Sudhir Srinivasa, Hui-Ling Lou
  • Patent number: 10772056
    Abstract: A first communication device generates a first portion and a second portion of a wakeup radio (WUR) wakeup packet. The first portion of the WUR wakeup packet corresponds to a wireless local area network (WLAN) legacy preamble, and spans a first frequency bandwidth. The second portion of the WUR wakeup packet spans a second bandwidth that is less than the first bandwidth, and is configured to cause a WUR of a second communication device to cause a WLAN network interface device of the second communication device to transition from a low power state to the active state. Generating the second portion of the WUR wakeup packet includes i) generating a sync portion having a plurality of sync symbols, and ii) generating a wakeup packet body. The first communication device transmits the WUR wakeup packet.
    Type: Grant
    Filed: July 30, 2018
    Date of Patent: September 8, 2020
    Assignee: Marvell Asia Pte, Ltd.
    Inventors: Hari Balakrishnan, Sri Varsha Rottela, Rui Cao, Hongyuan Zhang, Sudhir Srinivasa, Hua Mu, Xiayu Zheng
  • Publication number: 20200274686
    Abstract: A method for controlling communication of information includes selecting a group of stations within range of an access point, transmitting a first signal from the access point to a first station in the group, and receiving at the access point a second signal from a second station in the group. The first signal is transmitted to the first station through a downlink channel. The second signal is received from the second station through an uplink channel. Transmission of the first signal takes place during a first period and reception of the second signal takes place during a second period overlapping the first period, in order to perform full-duplex different-frequency communications based on an 802.11 standard between the access point and the first station and the second station.
    Type: Application
    Filed: February 21, 2020
    Publication date: August 27, 2020
    Inventors: Nilesh Nilkanth KHUDE, Vijay AHIRWAR, Hari Ram BALAKRISHNAN, Sri Varsha ROTTELA, Ankit SETHI, Sudhir SRINIVASA
  • Patent number: 10742780
    Abstract: In generating a physical layer (PHY) data unit for transmission via a communication channel, information bits to be included in the PHY data unit are received. A number of padding bits are added to the information bits. The number of padding bits is determined based on respective virtual values of each of one or more encoding parameters. The information bits are parsed to a number of encoders and are encoded, using the number of encoders, to generate coded bits. The coded bits are padded such that padded coded bits correspond to respective true values of each of the one or more encoding parameters. The PHY data unit is generated to include the padded coded bits.
    Type: Grant
    Filed: April 2, 2018
    Date of Patent: August 11, 2020
    Assignee: NXP USA, INC.
    Inventors: Sudhir Srinivasa, Hongyuan Zhang
  • Patent number: 10742357
    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: November 19, 2018
    Date of Patent: August 11, 2020
    Assignee: Marvell International Ltd.
    Inventors: Hongyuan Zhang, Sudhir Srinivasa, Rohit U. Nabar, Raja Banerjea
  • Patent number: 10735163
    Abstract: In a range measurement signal exchange session between a first communication device and a second communication device, the first communication device generates an NDP, which includes: generating a plurality of training fields to be used by the second communication device to determine a time of arrival of the NDP. Each training field corresponds to a respective orthogonal frequency divisional multiplexing (OFDM) symbol. Generating the plurality of training fields includes: i) setting signal samples corresponding to guard intervals between the OFDM symbols to zero, and ii) for each OFDM symbol, setting a plurality of frequency domain values corresponding to OFDM sub carriers of the OFDM symbol to complex number values. The first communication device transmits the NDP as part of the range measurement signal exchange session.
    Type: Grant
    Filed: January 30, 2019
    Date of Patent: August 4, 2020
    Assignee: Marvell International Ltd.
    Inventors: Christian R. Berger, Sudhir Srinivasa, Liwen Chu, Niranjan Grandhe
  • Patent number: 10728798
    Abstract: Some embodiments described herein provide a method for transmitting a preamble in accordance with a wireless local area network communication protocol. In some embodiments, a data frame may be obtained for transmission including a preamble compliant with the wireless local area network communication protocol. It may be determined that the preamble includes a first preamble portion that spans multiple symbol durations and a second preamble portion that spans a single symbol duration. The first preamble portion via beamforming may be transmitted based on a first beamforming matrix. When a transmission mode of the second preamble portion is beamforming, a second beamforming matrix may be generated based on the first beamforming matrix, each tone for the second preamble portion may be calculated based on the second beamforming matrix. Each calculated tone may be transmitted in accordance with the wireless local area network communication protocol.
    Type: Grant
    Filed: September 10, 2018
    Date of Patent: July 28, 2020
    Assignee: NXP USA, INC.
    Inventors: Yakun Sun, Hongyuan Zhang, Sudhir Srinivasa, Xiayu Zheng
  • Publication number: 20200196319
    Abstract: A method for transmitting a first physical layer (PHY) protocol data unit (PPDU) in a wireless local area network (WLAN) communication channel is described. One or more sectors of a service coverage area of a first communication device that are busy with a first transmission over the WLAN communication channel are identified. A second communication device is selected, using the identification of the one or more busy sectors, to receive the first PPDU during a second, directional transmission that at least partially temporally overlaps a duration of the first transmission. The first PPDU is generated for transmission to the second communication device. The first PPDU is transmitted to the second communication device as the second, directional transmission during the first transmission.
    Type: Application
    Filed: December 6, 2019
    Publication date: June 18, 2020
    Inventors: B Hari RAM, Vijay AHIRWAR, Sri Varsha ROTTELA, Nilesh N. KHUDE, Sudhir SRINIVASA
  • Patent number: 10673476
    Abstract: This disclosure describes a receiver having equalization with noise de-whitening mitigation for wireless communication. An input port receives, via an antenna, a signal communicated over a wireless communication link, the signal comprising a noise component. Control circuitry performs zero forcing equalization of the received signal to generate a zero forcing equalization result signal. The zero forcing equalization causes de-whitening of the noise component by increasing a correlation among elements of the noise component. The control circuitry mitigates the de-whitening of the noise component by: determining a noise variance value based on channel properties of the wireless communication link, and modifying the zero forcing equalization result signal based on the noise variance value. The modified zero forcing equalization result signal is communicated, via an output port, to log-likelihood ratio (LLR) generation circuitry for LLR computation.
    Type: Grant
    Filed: April 11, 2019
    Date of Patent: June 2, 2020
    Assignee: NXP USA, Inc.
    Inventors: Sayak Roy, Salil Kashyap, Ankit Sethi, Sudhir Srinivasa
  • Publication number: 20200169444
    Abstract: A millimeter-wave communication system includes a transmitter and a receiver. The transmitter is configured to be connected to a waveguide that is transmissive at millimeter-wave frequencies, the waveguide having a propagation parameter that varies with frequency at the millimeter-wave frequencies. The transmitter is configured to generate a millimeter-wave signal comprising multiple sub-carriers that are modulated with data, wherein each sub-carrier is modulated with a respective portion of the data and is subjected to only a respective fraction of a variation in the propagation parameter, and to transmit the millimeter-wave signal into a first end of the waveguide. The receiver is configured to receive the millimeter-wave signal from a second end of the waveguide, and to extract the data from the multiple sub-carriers.
    Type: Application
    Filed: July 31, 2019
    Publication date: May 28, 2020
    Inventors: Sai-Wang Tam, Su Chenxin, Vijay Ahirwar, Rulin Huang, Alden C. Wong, Rui Cao, Sudhir Srinivasa, Alireza Razzaghi, Randy Tsang, Timothy J. Donovan
  • Publication number: 20200163152
    Abstract: A WLAN Access Point (AP) includes a MAC processor and a PHY processor. The MAC processor is configured to generate a trigger frame including user information fields destined to respective STAs, and a padding field including one or more padding bits, to determine a number of padding bits that, after the trigger frame including the padding bats being encoded for transmission, satisfy a processing-time constraint imposed by the STAs, and to insert the determined number of padding bits in the padding field. The PHY processor is configured to generate a packet from the trigger frame, including encoding the trigger frame in accordance with an ECC, into one or more code words whose length depends on a number of padding bits in the padding field, to generate multiple modulated symbols from the one or more code words of the packet, and to transmit the modulated symbols to the STAs.
    Type: Application
    Filed: November 17, 2019
    Publication date: May 21, 2020
    Inventors: Sudhir Srinivasa, Hongyuan Zhang, Sri Varsha Rottela, B Hari Ram, Christian Raimund Berger
  • Publication number: 20200162964
    Abstract: A method for data transmission in a wireless local area network (WLAN). The method includes receiving, in a physical layer (PHY) interface of a first node in the WLAN, data for transmission over the WLAN. The received data are divided in the PHY interface into a sequence of data blocks having respective lengths, and encoding the data blocks using an error correcting code (ECC). The encoded data blocks are encapsulated in a PHY protocol data unit (PPDU) together with encoding metadata including at least an indication of the respective lengths of the data blocks. The PPDU is transmitted over the WLAN from the first node to a second node in the WLAN.
    Type: Application
    Filed: November 19, 2019
    Publication date: May 21, 2020
    Inventors: Sudhir Srinivasa, Hongyuan Zhang, Yan Zhang, Rui Cao, Liwen Chu
  • Patent number: 10656256
    Abstract: During a service period (SP) for a ranging measurement signal exchange between a first communication device and one or more second communication devices, the first communication device receives respective first null data packets (NDPs) from the one or more second communication devices, and transmits respective second NDPs to the one or more second communication devices. The first communication device transmits, during the SP, respective first ranging measurement feedback packets to the one or more second communication devices to allow each of the one or more second communication devices to determine a time-of-flight between the first communication device and the second communication device and/or receives, during the SP, respective second ranging measurement feedback packets from the one or more second communication devices to allow the first communication device to determine respective times-of-flight between the first communication device and the one or more second communication devices.
    Type: Grant
    Filed: April 6, 2018
    Date of Patent: May 19, 2020
    Assignee: Marvell Asia Pte, Ltd.
    Inventors: Liwen Chu, Sagar Tamhane, Hongyuan Zhang, Christian Berger, Niranjan Grandhe, Sudhir Srinivasa, Hui-Ling Lou
  • Publication number: 20200145268
    Abstract: A boundary within a last orthogonal frequency division multiplexing (OFDM) symbol of a PHY data unit is determined. Pre-encoder padding bits are added to a set of information bits to generate a set of padded information bits such that the set of padded information bits, after being encoded, fill one or more OFDM symbols up to the boundary within the last OFDM symbol. The set of padded information bits are encoded to generate a set of coded bits. A PHY preamble is generated to include a subfield that indicates the boundary. The one or more OFDM symbols are generated to include (i) the set of coded information bits in the one or more OFDM symbols up to the boundary to allow a receiving device to stop decoding the one or more OFDM symbols at the boundary, and (ii) post-encoder padding bits in the last OFDM symbol following the boundary.
    Type: Application
    Filed: November 4, 2019
    Publication date: May 7, 2020
    Inventors: Hongyuan ZHANG, Xiayu ZHENG, Rui CAO, Mingguang XU, Sudhir SRINIVASA, Jie HUANG
  • Publication number: 20200136753
    Abstract: A communication device generates a physical layer (PHY) data portion of a PHY data unit, including, for each of a plurality of PHY protocol service data units (PSDUs) to be included in the PHY data unit: selecting a segment boundary within a last-occurring orthogonal frequency division (OFDM) symbol from among a set of multiple segment boundaries, adding pre-forward error correction (pre-FEC) padding bits to the PSDU such that, after encoding the PSDU according to a forward error correction (FEC) code, coded bits of the PSDU end on the selected segment boundary, and individually encoding the PSDU according to the FEC code. The communication device generates a PHY preamble, which includes generating the PHY preamble to include a plurality of indications of a plurality of durations of the respective PSDUs within the PHY data portion.
    Type: Application
    Filed: October 29, 2019
    Publication date: April 30, 2020
    Inventors: Yan ZHANG, Liwen CHU, Rui CAO, Sudhir SRINIVASA, Hongyuan ZHANG