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).

  • Publication number: 20220021560
    Abstract: Embodiments of a method and an apparatus for beamforming are disclosed. In an embodiment, a method for beamforming involves transmitting, by a beamformer to a beamformee, a sounding packet that includes training symbols, receiving, at the beamformee, the sounding packet that includes the training symbols, deriving, at the beamformee, channel estimates from the training symbols included in the sounding packet, computing, at the beamformee, a feedback matrix from the derived channel estimates, transmitting, by the beamformee to the beamformer, a packet that includes two sets of symbols, where the feedback matrix is applied to at least one of the two sets of symbols, receiving, at the beamformer, the packet that includes the two sets of symbols, and operating the beamformer according to the two sets of symbols included in the packet.
    Type: Application
    Filed: July 13, 2021
    Publication date: January 20, 2022
    Inventors: Sayak Roy, Ankit Sethi, Sudhir Srinivasa
  • Patent number: 11229035
    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: Grant
    Filed: December 6, 2019
    Date of Patent: January 18, 2022
    Assignee: Marvell Asia Pte Ltd
    Inventors: B Hari Ram, Vijay Ahirwar, Sri Varsha Rottela, Nilesh N. Khude, Sudhir Srinivasa
  • Publication number: 20220014238
    Abstract: Embodiments of a method and an apparatus for wireless communications are disclosed. In an embodiment, a method for wireless communications involves assigning subcarriers of a first access point (AP) and a second AP to a subcarrier set of a virtual AP, generating, by the virtual AP, a packet that includes a signal for a station (STA) and that is transmitted using the subcarrier set, where generating the packet includes: encoding a preamble portion of the packet on the assigned subcarriers included in the subcarrier set, nulling the preamble portion of the packet for unassigned subcarriers of the first AP and the second AP, encoding a subsequent portion of the packet according to a Distributed Multiple-Input Multiple-Output (DMIMO) transmission, and transmitting the packet to the STA.
    Type: Application
    Filed: July 7, 2021
    Publication date: January 13, 2022
    Inventors: Hari Ram Balakrishnan, Sudhir Srinivasa
  • Patent number: 11212705
    Abstract: Techniques for signaling new versions of a communication protocol differentiated from legacy versions of the communication protocol that are interoperable with stations implementing legacy versions of the communication protocol, that are compatible with future new versions of the communication protocol, and that do not overly complicate the receiver state machine have been disclosed.
    Type: Grant
    Filed: May 22, 2020
    Date of Patent: December 28, 2021
    Assignee: NXP USA, Inc.
    Inventors: Rui Cao, Hongyuan Zhang, Liwen Chu, Sudhir Srinivasa
  • Publication number: 20210399850
    Abstract: A first device transmits to a second device a first data unit which indicates a maximum number of long training field (LTF) symbols that the first device transmits and receives for a multiple input multiple output communication. The first device receives, from the second device, a second data unit which comprises a plurality of LTF symbols up to the maximum number of LTF symbols the first device receives indicated by the first data unit. A channel estimation is performed based on the plurality of LTF symbols of the second data unit up to the maximum number of LTF symbols indicated by the first data unit to recover information in one or more fields of the second data unit. For the case when the second data unit is a trigger frame, the first device generates the third data unit with a plurality of LTF symbols up to the maximum number of LTF symbols the first device transmits indicated by the first data unit and transmits the third data unit.
    Type: Application
    Filed: June 22, 2021
    Publication date: December 23, 2021
    Inventors: Yan Zhang, Sudhir Srinivasa, Hongyuan Zhang, Rui Cao
  • Publication number: 20210392661
    Abstract: Embodiments of a method and an apparatus for wireless communications are disclosed. In an embodiment, a method for wireless communications involves generating a Physical Layer Protocol Data Unit (PPDU) that includes a resource unit (RU), wherein a size of the RU is less than a signal bandwidth and wherein data corresponding to the RU is distributed onto a disjoint set of subcarriers included in a frequency unit, and transmitting the PPDU using the disjoint set of subcarriers in accordance with a power spectrum density (PSD) limit.
    Type: Application
    Filed: June 16, 2021
    Publication date: December 16, 2021
    Inventors: Rui Cao, Hongyuan Zhang, Yan Zhang, Liwen Chu, Hari Ram Balakrishnan, Sudhir Srinivasa
  • Publication number: 20210385115
    Abstract: One example discloses an IEEE 802.11 compliant wireless communications device, including: a processor configured to generate a hybrid-physical protocol data unit (hybrid-PPDU) that includes a set of sub-PPDUs; a first sub-PPDU in the set of sub-PPDUs includes a first preamble portion and a first data payload portion; a second sub-PPDU in the set of sub-PPDUs includes a second preamble portion and a second data payload portion; wherein an OFDMA communications signal includes a set of symbol tones divided into a set of resource units (RUs); wherein the processor is configured to map the first sub-PPDU to a first RU within the set of RUs, and map the second sub-PPDU to a second RU within the set of RUs; and wherein the first preamble portion corresponds to a first 802.11 packet format, and the second preamble portion corresponds to a second 802.11 packet format.
    Type: Application
    Filed: February 22, 2021
    Publication date: December 9, 2021
    Inventors: Rui Cao, Liwen Chu, Young Hoon Kwon, Hongyuan Zhang, SUDHIR SRINIVASA
  • Publication number: 20210360472
    Abstract: In an 802.11be wireless system, data units are generated for transmission by configuring a transmitting device to process encoding parameters, including a first encoding parameter NSD and a second encoding parameter NSD,short, to select a padding boundary from pre-defined padding boundaries in the last symbol that will most closely include the number of information bits NEXCESS in the last symbol and to append padding bits to the number of information bits NEXCESS to fill up to the selected padding boundary in the last symbol, thereby generating pre-encoded data bits which are encoded for data transmission, where at least the first encoding parameter NSD is specified for an aggregated resource unit size that is allowed under the 802.11be protocol as a sum of NSD values for at two other resource units.
    Type: Application
    Filed: May 12, 2021
    Publication date: November 18, 2021
    Applicant: NXP USA, Inc.
    Inventors: Rui Cao, Sudhir Srinivasa, Hongyuan Zhang, Mao Yu
  • Patent number: 11171696
    Abstract: Various embodiments relate to a method for processing received distributed multiple-input and multiple-output (DMIMO) OFDM signals from a plurality of transmitters, including: performing an initial carrier frequency offset (CFO) correction; receiving a plurality of OFDM symbols; re-constructing the channel every N symbols based upon a channel estimate for each transmitter and an estimate of residual CFO for each of the transmitters based upon the long term fields (LTF), wherein N is an integer; and equalizing the received OFDM symbols using the re-constructed channel.
    Type: Grant
    Filed: July 30, 2020
    Date of Patent: November 9, 2021
    Assignee: NXP USA, Inc.
    Inventors: Hari Ram Balakrishnan, Sri Varsha Rottela, Ankit Sethi, Vijay Ahirwar, Nilesh Nilkanth Khude, Sudhir Srinivasa
  • Patent number: 11166159
    Abstract: The present disclosure describes methods and apparatuses for secure fine timing measurement (FTM) with encoded long training fields (LTFs). In some aspects, a device transmits an announcement frame for an FTM exchange that includes an indication of encoding. Based on the indication of encoding, an LTF of a first null data packet (NDP) of the FTM exchange is encoded. The device transmits the first NDP having the encoded LTF to another device, and receives, from the other device, a second NDP having an encoded LTF. A round-trip time for the first and second NDPs with encoded LTFs is determined. Based on this round-trip time, a distance between the device and the other device can be determined. By encoding the LTFs of the NDPs of the FTM exchange, third parties can be prevented from spoofing an FTM frame to compromise the FTM exchange and related proximity-based security.
    Type: Grant
    Filed: June 11, 2018
    Date of Patent: November 2, 2021
    Assignee: Marvell Asia PTE, Ltd.
    Inventors: Christian Raimund Berger, Liwen Chu, Sudhir Srinivasa, Niranjan Grandhe
  • Patent number: 11165614
    Abstract: One example discloses an OFDM wireless communications device, including: a memory configured to support processing of OFDM tones; a controller, coupled to the memory, and configured to set the wireless communication device to a first mode and a second mode; wherein the first mode is configured to transmit or receive a first wireless communication signal having a first set of OFDM tones contained within an OFDM channel bandwidth; wherein the second mode is configured to transmit or receive a second wireless communication signal having a second set of OFDM tones contained within the OFDM channel bandwidth; and wherein the memory used for processing the first set of OFDM tones is same as the memory used for processing the second set of OFDM tones.
    Type: Grant
    Filed: November 16, 2020
    Date of Patent: November 2, 2021
    Assignee: NXP USA, Inc.
    Inventors: Sudhir Srinivasa, Yui Lin, Hongyuan Zhang, Mao Yu, Timothy J. Donovan
  • Publication number: 20210336752
    Abstract: Embodiments of a method and an apparatus for wireless communications are disclosed. In an embodiment, a method for wireless communications involves operating an Access Point (AP) using feedback subcarrier indices for a bandwidth up to 320 MHz, signaling, by the AP, to a client, a subcarrier location set on which a feedback report is solicited, signaling, by the AP, to a client, a feedback type solicited on the subcarrier location, and indicating, by the client, feedback subcarrier indices for the subcarrier location set via the feedback report solicited by the AP.
    Type: Application
    Filed: April 23, 2021
    Publication date: October 28, 2021
    Inventors: Young Hoon Kwon, Rui Cao, Liwen Chu, Hongyuan Zhang, Hari Ram Balakrishnan, Sudhir Srinivasa, Sayak Roy, Xiayu Zheng
  • Patent number: 11159348
    Abstract: Embodiments described herein provide a system for transmitting high efficiency long term training field (HE-LTF) symbols for multiple wireless spatial streams over a wireless channel. An advanced P-matrix design is used to construct HE-LTF symbols that are processed by a receiver such that channel properties such as channel estimates or carrier phase error are determined prior to receiving all HE-LTF symbols. Tone multiplexing of wireless spatial stream is also used to transmit multiple spatial streams based on an assignment of sets of spatial streams to sets of tones available for transmission, increasing the throughput of the transmission system. The advanced P-matrix design and tone multiplexing are used in combination to achieve calculate channel properties before receiving all HE-LTF symbols while minimizing power fluctuation among the high efficiency short training field symbol and the HE-LTF symbols.
    Type: Grant
    Filed: September 18, 2019
    Date of Patent: October 26, 2021
    Assignee: Marvell Asia Pte, Ltd.
    Inventors: Ankit Sethi, Sayak Roy, Hari Ram Balakrishnan, Sudhir Srinivasa
  • Publication number: 20210320763
    Abstract: Various embodiments relate to a method for transmitting a Wi-Fi signal using a channel of 80 MHz or wider, wherein each 80 MHz segment has a tone plan, including: determining that a physical 20 MHz sub-channel overlaps the 80 MHz segment or OFDMA transmission is used for the 80 MHz segment; selecting an alternative 80 MHz tone plan; and transmitting data on the 80 MHz segment using the selected alternative 80 MHz tone plan.
    Type: Application
    Filed: March 25, 2021
    Publication date: October 14, 2021
    Inventors: Rui Cao, Sudhir Srinivasa, Hongyuan Zhang
  • Publication number: 20210321388
    Abstract: Communications may be effected in a communications environment involving a plurality channels having disparate bandwidth and channel center frequency indexes. Communications are effected using first communications type with a first channel bandwidth and first channel center frequency index. Communications are also effected via a second communications type using a separate set of fields indicating a second channel bandwidth and a second channel center frequency index, the second channel bandwidth being different than the first channel bandwidth and the second channel center frequency index being different than the first channel center frequency index. The channel center frequency index and bandwidth communicated in each communication may utilize separate subfields.
    Type: Application
    Filed: April 13, 2021
    Publication date: October 14, 2021
    Inventors: Young Hoon Kwon, Liwen Chu, Sudhir Srinivasa, Hongyuan Zhang, Rui Cao
  • Patent number: 11140709
    Abstract: A method for communication in a wireless local area network (WLAN) includes receiving, at first and second access points (APs) in the WLAN, uplink signals from a first client station (STA), which is associated with a basic service set (BSS) of the first AP. First downlink signals are transmitted from the first AP to the first STA using a first steering matrix. Responsively to the received uplink signals, a second steering matrix is computed, having a null in a direction of the first STA. Second downlink signals are transmitted from the second AP to a second STA in the WLAN using the second steering matrix.
    Type: Grant
    Filed: December 5, 2019
    Date of Patent: October 5, 2021
    Assignee: NXP USA, Inc.
    Inventors: B Hari Ram, Nilesh N. Khude, Sri Varsha Rottela, Vijay Ahirwar, Sudhir Srinivasa
  • Patent number: 11140745
    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: Grant
    Filed: November 17, 2019
    Date of Patent: October 5, 2021
    Assignee: NXP USA, Inc.
    Inventors: Sudhir Srinivasa, Hongyuan Zhang, Sri Varsha Rottela, B Hari Ram, Christian Raimund Berger
  • Publication number: 20210288754
    Abstract: A first portion of a physical layer (PHY) preamble of a PHY data unit is generated for transmission via a communication channel that comprises a plurality of sub-channels. A first portion of the PHY preamble is generated to include a legacy portion and a plurality of first non-legacy signal fields spanning the respective sub-channels. A second portion of a PHY preamble that immediately follows the first portion of the PHY preamble of the PHY data unit is generated to include: a non-legacy short training field spanning all sub-channels in the plurality of sub-channels, a plurality of non-legacy long training fields immediately following the non-legacy short training field, each non-legacy training field spanning all sub-channels in the plurality of sub-channels, and a second non-legacy signal field immediately following the plurality of non-legacy long training fields, the second-legacy signal field spanning all sub-channels in the plurality of sub-channels.
    Type: Application
    Filed: May 28, 2021
    Publication date: September 16, 2021
    Inventors: Hongyuan ZHANG, Hui-Ling LOU, Rohit U. NABAR, Sudhir SRINIVASA, Mao YU, Raja BANERJEA
  • Publication number: 20210266890
    Abstract: A method and an apparatus for operating a Basic Service Set (BSS) are disclosed. A method involves announcing, by a first wireless device to a second wireless device, a BSS operating channel, wherein the first wireless device has at least one of a first transmission power capability and a first bandwidth capability, the second wireless device has at least one of a second transmission power capability that is less than the first transmission power capability and a second bandwidth capability that is narrower than the first bandwidth capability, and wherein the BSS operating channel is at least one of a punctured operating channel and an unpunctured operating channel, associating, by the second wireless device, with the first wireless device via the announcement of the BSS operating channel from the first wireless device, and exchanging frames between the first wireless device and the second wireless device in the BSS operating channel.
    Type: Application
    Filed: February 22, 2021
    Publication date: August 26, 2021
    Inventors: Liwen CHU, Rui CAO, Sudhir SRINIVASA, Hongyuan ZHANG, Huiling LOU, Young Hoon KWON
  • Publication number: 20210266386
    Abstract: Embodiments of a method and an apparatus for wireless communications are disclosed. In an embodiment, a method for wireless communications involves encoding bits in a first preamble portion of a packet that are defined on a per-channel basis and that are repeated across multiple frequency blocks of a bandwidth, encoding bits in a second preamble portion of the packet that are defined on the per-channel basis and that are repeated within at least one frequency block of the bandwidth, encoding bits in a third preamble portion of the packet that are defined on a two-channel basis and that are repeated within at least one frequency block of the bandwidth, padding the third preamble portion of the packet to have a same length for each of the frequency blocks, and transmitting the packet.
    Type: Application
    Filed: February 22, 2021
    Publication date: August 26, 2021
    Inventors: Rui Cao, Liwen Chu, Sudhir Srinivasa, Hongyuan Zhang, Yan Zhang, Xiayu Zheng