Patents by Inventor Badri Varadarajan

Badri Varadarajan 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: 9225397
    Abstract: The present disclosure provides a receiver, a transmitter and methods of operating a receiver or a transmitter. In one embodiment, the receiver includes a receive unit configured to receive transmissions from multiple antennas. The receiver also includes a rank feedback unit configured to feed back a transmission rank selection, wherein the transmission rank selection corresponds to a transmission rank feedback reduction scheme. The receiver further includes a precoding feedback unit configured to feed back a precoding matrix selection, wherein the precoding matrix selection corresponds to a precoding matrix feedback reduction scheme.
    Type: Grant
    Filed: July 9, 2008
    Date of Patent: December 29, 2015
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Runhua Chen, Eko N. Onggosanusi, Badri Varadarajan, Anand G. Dabak
  • Publication number: 20150295627
    Abstract: The present disclosure provides a receiver, a transmitter and methods of operating a receiver or a transmitter. In one embodiment, the receiver includes a receive unit configured to receive transmissions from multiple antennas. The receiver also includes a rank feedback unit configured to feed back a transmission rank selection, wherein the transmission rank selection corresponds to a transmission rank feedback reduction scheme. The receiver further includes a precoding feedback unit configured to feed back a preceding matrix selection, wherein the preceding matrix selection corresponds to a preceding matrix feedback reduction schemes.
    Type: Application
    Filed: June 23, 2015
    Publication date: October 15, 2015
    Inventors: Runhua Chen, Eko Nugroho Onggosanusi, Badri Varadarajan, Anand Ganesh Dabak
  • Patent number: 9148181
    Abstract: A wireless receiver providing multiple services (FIG. 3) is disclosed. The wireless receiver includes an oscillator circuit (304, FIG. 4) arranged to produce a reference frequency (308). A first receiver (302) receives a first signal (300) having a first carrier frequency in response to the reference frequency. A second receiver (322) receives a second signal (320) having a second carrier frequency different from the first carrier frequency in response to the reference frequency.
    Type: Grant
    Filed: June 8, 2007
    Date of Patent: September 29, 2015
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Charles Kasimer Sestok, Badri Varadarajan, Anand Ganesh Dabak
  • Publication number: 20150223082
    Abstract: A backhaul radio is disclosed that operates in multipath propagation environments such as obstructed LOS conditions with uncoordinated interference sources in the same operating band. Such a backhaul radio may use a combination of interference mitigation procedures across multiple of the frequency, time, spatial and cancellation domains. Such backhaul radios may communicate with each other to coordinate radio resource allocations such that accurate interference assessment and channel propagation characteristics assessment may be determined during normal operation.
    Type: Application
    Filed: April 16, 2015
    Publication date: August 6, 2015
    Inventors: Kevin J. Negus, Sagnik Ghosh, Badri Varadarajan
  • Patent number: 9048918
    Abstract: Embodiments of the present disclosure provide a transmitter, a receiver and methods of operating a transmitter and a receiver. In one embodiment, the transmitter has at least three transmit antennas and includes a feedback decoding portion configured to recover at least one group-based channel quality indicator provided by a feedback signal from a receiver, wherein each group-based channel quality indicator corresponds to one of a set of transmission layer groupings. The transmitter also includes a modulator portion configured to generate at least one symbol stream and a mapping portion configured to multiplex each symbol stream to at least one transmission layer grouping. The transmitter further includes a pre-coder portion configured to couple the transmission layers to the transmit antennas for a transmission. The receiver includes a decoder portion which is configured to use decoded signals from at least one group to decode the other groups.
    Type: Grant
    Filed: September 30, 2014
    Date of Patent: June 2, 2015
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Badri Varadarajan, Eko N. Onggosanusi
  • Patent number: 9049611
    Abstract: A backhaul radio is disclosed that operates in multipath propagation environments such as obstructed LOS conditions with uncoordinated interference sources in the same operating band. Such a backhaul radio may use a combination of interference mitigation procedures across multiple of the frequency, time, spatial and cancellation domains. Such backhaul radios may communicate with each other to coordinate radio resource allocations such that accurate interference assessment and channel propagation characteristics assessment may be determined during normal operation.
    Type: Grant
    Filed: September 26, 2014
    Date of Patent: June 2, 2015
    Assignee: CBF NETWORKS, INC.
    Inventors: Kevin J. Negus, Sagnik Ghosh, Badri Varadarajan
  • Patent number: 8964786
    Abstract: Systems and methods for designing, using, and/or implementing communications in beacon-enabled networks are described. In various implementations, these systems and methods may be applicable to power line communications (PLC). For example, a method may include identifying one of a plurality of orthogonal superframes. The identified superframe may include beacon slots and contention access period (CAP) slots. The beacon slots may follow a sequence of two or more frequency subbands, and the CAP slots may follow the same sequence of two or more frequency subbands. Also, the sequence of two or more frequency subbands may be distinct from other sequences of two or more frequency subbands followed by other beacon slots and CAP slots within others of the plurality of available superframes. The method may then include communicating with another device using the identified superframe.
    Type: Grant
    Filed: March 30, 2012
    Date of Patent: February 24, 2015
    Assignee: Texas Instruments Incorporated
    Inventors: Kumaran Vijayasankar, Shu Du, Anand Dabak, Badri Varadarajan, Il Han Kim, Xiaolin Lu
  • Publication number: 20150049720
    Abstract: A backhaul radio is disclosed that operates in multipath propagation environments such as obstructed LOS conditions with uncoordinated interference sources in the same operating band. Such a backhaul radio may use a combination of interference mitigation procedures across multiple of the frequency, time, spatial and cancellation domains. Such backhaul radios may communicate with each other to coordinate radio resource allocations such that accurate interference assessment and channel propagation characteristics assessment may be determined during normal operation.
    Type: Application
    Filed: September 26, 2014
    Publication date: February 19, 2015
    Inventors: Kevin J. Negus, Sagnik Ghosh, Badri Varadarajan
  • Publication number: 20150030058
    Abstract: The present disclosure provides a receiver, a transmitter and methods of operating a receiver and a transmitter. In one embodiment, the receiver includes a receive portion employing transmission signals from a transmitter, having multiple transmit antennas, that is capable of transmitting at least one spatial codeword and adapting a transmission rank. The receiver also includes a feedback generator portion configured to provide a channel quality indicator that is feedback to the transmitter, wherein the channel quality indicator corresponds to at least one transmission rank.
    Type: Application
    Filed: June 6, 2007
    Publication date: January 29, 2015
    Applicant: Texas Instruments Inc.
    Inventors: Badri Varadarajan, Eko N. Onggosanusi
  • Patent number: 8909061
    Abstract: A method is provided for performing chromatic dispersion (CD) pre-compensation. The method generates an electronic signal at a transmitter, and uses a transmit CD compensation estimate to compute a CD pre-compensation filter. The transmit CD pre-compensation filter is used to process the electronic signal, generating a pre-compensated electronic signal. The pre-compensated electronic signal is converted into an optical signal and transmitted to an optical receiver via an optical channel. In one aspect, the transmitter generates a test electronic signal and the CD compensation estimate uses a first dispersion value to compute a first CD compensation filter. The transmitter accepts a residual dispersion estimate of the test optical signal from the first optical receiver CD compensation filter, generated from a (receiver-side) CD estimate, and then the transmit CD estimate can be modified in response to the combination of the first dispersion value and residual dispersion estimate.
    Type: Grant
    Filed: May 2, 2012
    Date of Patent: December 9, 2014
    Assignee: Applied Micro Circuits Corporation
    Inventor: Badri Varadarajan
  • Patent number: 8848852
    Abstract: Embodiments of the present disclosure provide a transmitter, a receiver and methods of operating a transmitter and a receiver. In one embodiment, the transmitter has at least three transmit antennas and includes a feedback decoding portion configured to recover at least one group-based channel quality indicator provided by a feedback signal from a receiver, wherein each group-based channel quality indicator corresponds to one of a set of transmission layer groupings. The transmitter also includes a modulator portion configured to generate at least one symbol stream and a mapping portion configured to multiplex each symbol stream to at least one transmission layer grouping. The transmitter further includes a pre-coder portion configured to couple the transmission layers to the transmit antennas for a transmission. The receiver includes a decoder portion which is configured to use decoded signals from at least one group to decode the other groups.
    Type: Grant
    Filed: May 10, 2011
    Date of Patent: September 30, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Badri Varadarajan, Eko N. Onggosanusi
  • Patent number: 8831077
    Abstract: Systems and methods are disclosed for communicating on a pilot wire between Electric Vehicle Service Equipment (EVSE) and an Electric Vehicle (EV). The EVSE and EV exchange a Pulse Width Modulation (PWM) signal on the pilot wire to control charging operations of the EV. Data communications may also be transmitted on the pilot wire, such as between transmit and receive modems. The modems transmit communication signals either continuously, without regard to the state of the PWM signal, or only when the PWM is in an off-state. If transmitting while PWM is on, the modem needs a large coupling impedance and/or a large signal injection. To transmit only when the PWM is off, the modem may use a blocking diode in the coupling circuit or may synchronize to the pulses in the PWM signal.
    Type: Grant
    Filed: June 17, 2011
    Date of Patent: September 9, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Badri Varadarajan, Il Han Kim, Anand Dabak, Edward Mullins
  • Patent number: 8830984
    Abstract: Embodiments of the present disclosure provide a transmitter, a receiver and methods of operating a transmitter and a receiver. In one embodiment, the transmitter includes a synchronization unit configured to provide a primary synchronization signal and a secondary synchronization signal having first and second segments. The transmitter also includes a secondary scrambling unit configured to provide a scrambled secondary synchronization signal, wherein scrambling agents for the first and second segments are derived from a primary synchronization sequence of the primary synchronization signal. The secondary scrambling unit is further configured to provide an additional scrambling of one of the first and second segments, wherein a second scrambling agent is derived from the remaining segment of a secondary synchronization sequence of the secondary synchronization signal.
    Type: Grant
    Filed: April 2, 2012
    Date of Patent: September 9, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Anand G. Dabak, Eko N. Onggosanusi, Badri Varadarajan
  • Patent number: 8817818
    Abstract: A transmitter includes a bandwidth configuration unit configured to provide an increased system bandwidth corresponding to a bandwidth extension over multiple component carriers. Additionally, the transmitter also includes a transmit unit configured to employ the bandwidth extension.
    Type: Grant
    Filed: April 21, 2009
    Date of Patent: August 26, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Eko N. Onggosanusi, Anand G. Dabak, Badri Varadarajan, Runhua Chen, Tarik Muharemovic
  • Publication number: 20140226739
    Abstract: The present invention provides a receiver. In one embodiment, the receiver includes a receive portion employing transmission signals from a transmitter having multiple antennas and capable of providing channel estimates. The receiver also includes a feedback generator portion configured to provide to the transmitter a pre-coder selection for data transmission that is based on the channel estimates, wherein the pre-coder selection corresponds to a grouping of frequency-domain resource blocks. The present invention also provides a transmitter having multiple antennas. In one embodiment, the transmitter includes a transmit portion coupled to the multiple antennas and capable of applying pre-coding to a data transmission for a receiver. The transmitter also includes a feedback decoding portion configured to decode a pre-coder selection for the data transmission that is fed back from the receiver, wherein the pre-coder selection corresponds to a grouping of frequency-domain resource blocks.
    Type: Application
    Filed: February 12, 2013
    Publication date: August 14, 2014
    Applicant: Texas Instruments Incorporated
    Inventors: Eko N. ONGGOSANUSI, Badri VARADARAJAN, Anand Ganesh DABAK
  • Patent number: 8792789
    Abstract: A method is provided for performing chromatic dispersion (CD) compensation. A zero-forcing filter is calculated with a number of taps (n) required to nullify a chromatic dispersion frequency response of an optical channel. The number of taps in the zero-forcing filter is truncated to a number equal to (n?x), where x is an integer greater than 0. In one aspect, the chromatic dispersion frequency response of the optical channel is partitioned into a plurality of constituent chromatic dispersion responses, and a zero-forcing filter is calculated for each of the plurality of constituent chromatic dispersion responses. The number of taps in each of the plurality of zero-forcing filters is truncated, and the CD compensation filter is formed for each of the plurality of truncated tap zero-forcing filters. In another aspect, the tap values of the zero-forcing filter are quantized to a finite quantization set.
    Type: Grant
    Filed: March 7, 2012
    Date of Patent: July 29, 2014
    Assignee: Applied Micro Circuits Corporation
    Inventors: Badri Varadarajan, Daruish Dabiri, Subhash Roy
  • Patent number: 8755453
    Abstract: In one embodiment, a transmitter includes a binary sequence generator unit configured to provide a sequence of reference signal bits, wherein the sequence is an inseparable function of a cell identification parameter, a cyclic prefix mode corresponding to the transmitter and one or more time indices of the sequence. The transmitter also include a mapping unit that transforms the sequence of reference signal bits into a complex reference signal, and a transmit unit configured to transmit the complex reference signal. In another embodiment, a receiver includes a receive unit configured to receive a complex reference signal and a reference signal decoder unit configured to detect a sequence of reference signal bits from the complex reference signal, wherein the sequence is an inseparable function of a cell identification parameter, a cyclic prefix mode corresponding to a transmitter and one or more time indices of the sequence.
    Type: Grant
    Filed: December 2, 2008
    Date of Patent: June 17, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Badri Varadarajan, Anand G. Dabak, Tarkesh Pande, Eko N. Onggosanusi
  • Patent number: 8649443
    Abstract: A device for communicating digital data over power lines includes a power line interface for transmitting data over at least one band of frequencies. An orthogonal frequency division multiplexing (OFDM) modulation unit generates OFDM symbols using a set of tones for the frequency band. A preamble generation unit generates preamble sequences for the frequency band by using the set of tones used by the OFDM modulation unit. The tones used by the preamble generation unit have a constant magnitude, and a set of phases obtained by quantizing to a small alphabet the phase of a set of tones obtained by taking an IFFT of a portion of a preamble used by a non-interoperable powerline access device. The device may transmit on two or more bands using a sampling frequency clock, wherein a lower band clock frequency is equal to or an integer divisor of a higher band clock frequency.
    Type: Grant
    Filed: April 27, 2010
    Date of Patent: February 11, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Badri Varadarajan, Anand Dabak, Shu Du, Il Han Kim
  • Patent number: 8625689
    Abstract: Embodiments of the invention provide time-domain link adaptation in power line communications. In one embodiment, the cyclic prefix length and position is adjusted with an OFDM symbol to overlap a periodic impulse noise pulse, thereby allowing the data carried in the symbol to be detected at a receiver. The cyclic prefix may be adjusted to provide a pattern that yields an integer number of OFDM symbols in one zero crossing period. The data rate used for the symbols overlapping the zero-crossing period may be zero or very low. A high data rate may be used for symbols outside the zero-crossing period because those symbols will not be affected by the periodic impulse noise.
    Type: Grant
    Filed: July 8, 2011
    Date of Patent: January 7, 2014
    Assignee: Texas Instruments Incorporated
    Inventors: Badri Varadarajan, Anand Dabak, Il Han Kim
  • Patent number: 8290492
    Abstract: A method of wireless handover in a broadcast network (FIGS. 5 and 8) is disclosed. A wireless receiver (FIG. 4) receives a first signal (N) from a first transmitter (f1). The receiver measures a signal strength (RSSI) of the first signal. The strength of the first signal is compared to a first threshold (T0). The receiver receives a second signal (N+3) from a second transmitter (f3) in response to the step of comparing. The first and the second signals are sent to an application processor (120). The wireless receiver continues to receive the first and second signals until the application processor terminates receiving one of the first and second signals.
    Type: Grant
    Filed: May 4, 2007
    Date of Patent: October 16, 2012
    Assignee: Texas Instruments Incorporated
    Inventors: Xiaolin Lu, Rao P. Venkatasadasiva, Zigang Yang, Anand Ganesh Dabak, Badri Varadarajan, Srinath Hosur, Susan Yim