Patents by Inventor Raghunath K. Rao

Raghunath K. Rao 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: 20170363731
    Abstract: A radar sensing system for a vehicle includes a transmitter, a receiver, a memory, and a processor. The transmitter transmits a radio signal and the receiver receives a reflected radio signal. The processor samples reflected radio signals during a plurality of time slices. The processor produces samples by correlating reflected radio signals to time-delayed replicas of transmitted radio signals. The processor accumulates the time slices into a first radar data cube (RDC) and selectively processes a portion of the first RDC to produce a first partial Doppler output. The processor produces samples during a second scan and accumulates time slices into a second RDC, and then selectively processes a portion of the second RDC to produce a second partial Doppler output. The processor numerically accumulates the first and second partial Doppler outputs to create a full Doppler output and stores the full Doppler output in memory.
    Type: Application
    Filed: August 30, 2017
    Publication date: December 21, 2017
    Inventors: Jean P. Bordes, Raghunath K. Rao, Monier Maher
  • Patent number: 9846228
    Abstract: A radar system processes signals in a flexible, adaptive manner to determine range, Doppler (velocity) and angle of objects in an environment. The radar system processes the received signal to achieve different objectives depending on the environment, the current information stored in the radar system, and/or external information provided to the radar system. The system allows improved resolution of range, Doppler and/or angle depending on the desired objective.
    Type: Grant
    Filed: April 25, 2017
    Date of Patent: December 19, 2017
    Assignee: UHNDER, INC.
    Inventors: Curtis Davis, Monier Maher, Jean P. Bordes, Manju Hegde, Otto A. Schmid, Raghunath K. Rao, Marius Goldenberg, Aria Eshraghi, Vito Giannini, David S. Trager, Nikhilesh Bhagat, Srikanth Gollapudi, Sundar Govindarajan, Steve Borho, Jonathan Preussner, Paul W. Dent, Paul Bassett, Stephen W. Alland, Fred Harris, Wayne E. Stark, Murtaza Ali
  • Patent number: 9829567
    Abstract: A radar sensing system includes at least one transmitter, at least one receiver and a processor. The at least one transmitter transmits a power shaped radio signal. The at least one receiver receives radio signal that includes the transmitted radio signal reflected from targets in the environment. The received radio signal is provided to the processor. The processor samples the received radio signal during a plurality of time intervals to produce a sampled stream. The different time intervals of the plurality of time intervals will contain different signal levels of radio signals reflected from the targets. The processor also selects a particular time interval of the plurality of time intervals that is free of samples of radio signals reflected off of the targets that are closer than a first threshold distance from an equipped vehicle.
    Type: Grant
    Filed: August 30, 2017
    Date of Patent: November 28, 2017
    Assignee: UHNDER, INC.
    Inventors: Curtis Davis, Jean P. Bordes, Monier Maher, Wayne Stark, Raghunath K. Rao
  • Patent number: 9806914
    Abstract: A radar sensing system for a vehicle includes a transmitter, a receiver, and an interference mitigation processor. The transmitter transmits radio signals. The receiver receives radio signals. The received radio signals include reflected radio signals that are each transmitted radio signals reflected from objects in the environment. The receiver also down-converts and digitizes the received radio signals to produce a baseband sampled stream. The interference mitigation processor produces a second received radio signal that includes reflected radio signals that are transmitted radio signals reflected from a first object. The interference mitigation processor uses the second received radio signal to remove selected samples from the baseband sampled stream that are attributed to radio signals reflected from the first object to produce a modified baseband sampled stream. The receiver uses the modified baseband sampled stream to detect a second object more distant than the first object.
    Type: Grant
    Filed: April 19, 2017
    Date of Patent: October 31, 2017
    Assignee: UHNDER, INC.
    Inventors: Jean P. Bordes, Aria Eshraghi, David S. Trager, Murtaza Ali, Raghunath K. Rao
  • Publication number: 20170310507
    Abstract: A radar sensing system for a vehicle includes a transmitter, a receiver, and an interference mitigation processor. The transmitter transmits radio signals. The receiver receives radio signals. The received radio signals include reflected radio signals that are each transmitted radio signals reflected from objects in the environment. The receiver also down-converts and digitizes the received radio signals to produce a baseband sampled stream. The interference mitigation processor produces a second received radio signal that includes reflected radio signals that are transmitted radio signals reflected from a first object. The interference mitigation processor uses the second received radio signal to remove selected samples from the baseband sampled stream that are attributed to radio signals reflected from the first object to produce a modified baseband sampled stream. The receiver uses the modified baseband sampled stream to detect a second object more distant than the first object.
    Type: Application
    Filed: April 19, 2017
    Publication date: October 26, 2017
    Inventors: Jean P. Bordes, Aria Eshraghi, David S. Trager, Murtaza Ali, Raghunath K. Rao
  • Publication number: 20170307753
    Abstract: A radar sensing system for a vehicle includes a transmitter configured for installation and use on a vehicle and able to transmit radio signals. The radar sensing system also includes a receiver and a processor. The receiver is configured for installation and use on the vehicle and able to receive radio signals. The received radio signals include transmitted radio signals that are reflected from objects in the environment. The received radio signals further include radio signals transmitted by at least one other radar system. The processor samples the received radio signals to produce a sampled stream. The processor is configured to control an adaptive filter. Responsive to the processor, the adaptive filter is configured to filter the sampled stream, such that the radio signals transmitted by the at least one other radar system are removed from the received radio signals.
    Type: Application
    Filed: April 20, 2017
    Publication date: October 26, 2017
    Inventors: Fred Harris, David Trager, Curtis Davis, Raghunath K. Rao
  • Publication number: 20170307729
    Abstract: A digital FMCW radar is described that simultaneously transmits and receives digitally frequency modulated signals using multiple transmitters and multiple receivers and associated antennas. Several sources of nearby spillover from transmitters to receivers that would otherwise degrade receiver performance are subtracted by a cancellation system in the analog radio frequency domain that adaptively synthesizes an analog subtraction signal based on residual spillover measured by a correlator operating in the receivers' digital signal processing domains and based on knowledge of the transmitted waveforms. The first adaptive cancellation system achieves a sufficient reduction of transmit-receive spillover to avoid receiver saturation or other non-linear effects, but is then added back in to the signal path in the digital domain after analog-to-digital conversion so that spillover cancellation can also operate in the digital signal processing domain to remove deleterious spillover components.
    Type: Application
    Filed: April 25, 2017
    Publication date: October 26, 2017
    Inventors: Aria Eshraghi, Jean P. Bordes, Curtis Davis, Raghunath K. Rao, Murtaza Ali, Paul W. Dent
  • Patent number: 9791564
    Abstract: A radar sensing system for a vehicle includes a transmitter configured for installation and use on a vehicle and able to transmit radio signals. The radar sensing system also includes a receiver and a processor. The receiver is configured for installation and use on the vehicle and able to receive radio signals. The received radio signals include transmitted radio signals that are reflected from objects in the environment. The received radio signals further include radio signals transmitted by at least one other radar system. The processor samples the received radio signals to produce a sampled stream. The processor is configured to control an adaptive filter. Responsive to the processor, the adaptive filter is configured to filter the sampled stream, such that the radio signals transmitted by the at least one other radar system are removed from the received radio signals.
    Type: Grant
    Filed: April 20, 2017
    Date of Patent: October 17, 2017
    Assignee: UHNDER, INC.
    Inventors: Fred Harris, David Trager, Curtis Davis, Raghunath K. Rao
  • Patent number: 9791551
    Abstract: A digital FMCW radar is described that simultaneously transmits and receives digitally frequency modulated signals using multiple transmitters and multiple receivers and associated antennas. Several sources of nearby spillover from transmitters to receivers that would otherwise degrade receiver performance are subtracted by a cancellation system in the analog radio frequency domain that adaptively synthesizes an analog subtraction signal based on residual spillover measured by a correlator operating in the receivers' digital signal processing domains and based on knowledge of the transmitted waveforms. The first adaptive cancellation system achieves a sufficient reduction of transmit-receive spillover to avoid receiver saturation or other non-linear effects, but is then added back in to the signal path in the digital domain after analog-to-digital conversion so that spillover cancellation can also operate in the digital signal processing domain to remove deleterious spillover components.
    Type: Grant
    Filed: April 25, 2017
    Date of Patent: October 17, 2017
    Assignee: UHNDER, INC.
    Inventors: Aria Eshraghi, Jean P. Bordes, Curtis Davis, Raghunath K. Rao, Murtaza Ali, Paul W. Dent
  • Publication number: 20170293027
    Abstract: A radar system has different modes of operation. In one mode the radar operates as a single-input, multiple-output (SIMO) radar system utilizing one transmitted signal from one antenna at a time. Codes with known excellent autocorrelation properties are utilized in this mode. At each receiver the response after correlating with various possible transmitted signals is measured in order to estimate the interference that each transmitter will represent at each receiver. The estimated effect of the interference from one transmitter on a receiver that correlates with a different code is used to mitigate the interference. In another mode, the radar operates as a MIMO radar system utilizing all the antennas at a time. Interference cancellation of the non-ideal cross correlation sidelobes when transmitting in the MIMO mode are employed to remove ghost targets due to unwanted sidelobes.
    Type: Application
    Filed: June 26, 2017
    Publication date: October 12, 2017
    Inventors: Wayne E. Stark, Jean P. Bordes, Curtis Davis, Raghunath K. Rao, Monier Maher, Manju Hegde, Otto A. Schmid
  • Publication number: 20170293025
    Abstract: A radar system processes signals in a flexible, adaptive manner to determine range, Doppler (velocity) and angle of objects in an environment. The radar system processes the received signal to achieve different objectives depending on the environment, the current information stored in the radar system, and/or external information provided to the radar system. The system allows improved resolution of range, Doppler and/or angle depending on the desired objective.
    Type: Application
    Filed: April 25, 2017
    Publication date: October 12, 2017
    Inventors: Curtis Davis, Monier Maher, Jean P. Bordes, Manju Hegde, Otto A. Schmid, Raghunath K. Rao, Marius Goldenberg, Aria Eshraghi, Vito Giannini, David S. Trager, Nikhilesh Bhagat, Srikanth Gollapudi, Sundar Govindarajan, Steve Borho, Jonathan Preussner, Paul W. Dent, Paul Bassett, Stephen W. Alland, Fred Harris, Wayne E. Stark, Murtaza Ali
  • Patent number: 9772397
    Abstract: A radar sensing system for a vehicle includes at least one transmitter, at least one receiver, and a processor. The at least one transmitter is operable to transmit a radio signal at one of a plurality of carrier frequencies. The at least one receiver is operable to receive a radio signal which includes a reflected radio signal that is the transmitted radio signal reflected from an object. The at least one receiver is operable to receive an interfering radio signal transmitted by a transmitter of another radar sensing system. The processor is operable to control the at least one transmitter to selectively transmit radio signals on one of the plurality of carrier frequencies. The processor is further operable to at least one of select a carrier frequency with reduced interference and avoid interference from the other radar sensing system.
    Type: Grant
    Filed: January 26, 2017
    Date of Patent: September 26, 2017
    Assignee: UHNDER, INC.
    Inventors: Jean P. Bordes, Curtis Davis, Wayne E. Stark, Otto A. Schmid, Raghunath K. Rao
  • Patent number: 9753121
    Abstract: A radar sensing system includes at least one transmitter, at least one receiver and a processor. The at least one transmitter transmits a power shaped RF signal. The transmitted RF signal decreases in power over time. The at least one receiver receives a reflected RF signal. The reflected RF signal is the transmitted RF signal reflected from targets in the environment. The reflected RF signal is down-converted and the result provided to the processor. The processor samples the down-converted reflected RF signal during a plurality of time intervals to produce a sampled stream. The different time intervals of the plurality of time intervals will contain different signal levels of RF signals reflected from the targets. The processor also selects samples in the sampled stream over a selected time interval of the plurality of time intervals that is free of RF signals reflected off of near targets.
    Type: Grant
    Filed: October 13, 2016
    Date of Patent: September 5, 2017
    Assignee: UHNDER, INC.
    Inventors: Curtis Davis, Jean P. Bordes, Monier Maher, Wayne Stark, Raghunath K. Rao
  • Patent number: 9753132
    Abstract: A radar sensing system for a vehicle includes a transmitter, a receiver, a memory, and a processor. The transmitter transmits a radio signal and the receiver receives a reflected radio signal. The processor samples reflected radio signals during a plurality of time slices. The processor produces samples by correlating reflected radio signals to time-delayed replicas of transmitted radio signals. The processor accumulates the time slices into a first radar data cube and stores the first radar data cube in a memory. The processor combines a portion of the first radar data cube with a portion of a previously stored radar data cube. Based at least in part on the combined portions of the radar data cubes, the processor processes a time series that is a time series of the first radar data cube concatenated with a time series from the previously stored radar data cube.
    Type: Grant
    Filed: March 20, 2017
    Date of Patent: September 5, 2017
    Assignee: UHNDER, INC.
    Inventors: Jean P. Bordes, Raghunath K. Rao, Monier Maher
  • Patent number: 9689967
    Abstract: A radar system has different modes of operation. In one mode the radar operates as a single-input, multiple-output (SIMO) radar system utilizing one transmitted signal from one antenna at a time. Codes with known excellent autocorrelation properties are utilized in this mode. At each receiver the response after correlating with various possible transmitted signals is measured in order to estimate the interference that each transmitter will represent at each receiver. The estimated effect of the interference from one transmitter on a receiver that correlates with a different code is used to mitigate the interference. In another mode, the radar operates as a MIMO radar system utilizing all the antennas at a time. Interference cancellation of the non-ideal cross correlation sidelobes when transmitting in the MIMO mode are employed to remove ghost targets due to unwanted sidelobes.
    Type: Grant
    Filed: April 7, 2017
    Date of Patent: June 27, 2017
    Assignee: UHNDER, INC.
    Inventors: Wayne E. Stark, Jean P. Bordes, Curtis Davis, Raghunath K. Rao, Monier Maher, Manju Hegde, Otto A. Schmid
  • Patent number: 9599702
    Abstract: A radar sensing system for a vehicle includes a transmitter, a receiver, a memory, and a processor. The transmitter transmits a radio signal and the receiver receives a reflected radio signal. The processor samples reflected radio signals during a plurality of time slices. The processor produces samples by correlating reflected radio signals to time-delayed replicas of transmitted radio signals. The processor accumulates the time slices into a first radar data cube and stores the first radar data cube in a memory. The processor combines a portion of the first radar data cube with a portion of a previously stored radar data cube. Based at least in part on the combined portions of the radar data cubes, the processor processes a time series that is a time series of the first radar data cube concatenated with a time series from the previously stored radar data cube.
    Type: Grant
    Filed: July 7, 2016
    Date of Patent: March 21, 2017
    Assignee: UHNDER, INC.
    Inventors: Jean P. Bordes, Raghunath K. Rao, Monier Maher
  • Patent number: 6950794
    Abstract: A method of encoding a digital signal, particularly an audio signal, which predicts favorable scalefactors for different frequency subbands of the signal. Distortion thresholds which are associated with each of the frequency subbands of the signal are used, along with transform coefficients, to calculate total scaling values, one for each of the frequency subbands, such that the product of a transform coefficient for a given subband with its respective total scaling value is less than a corresponding one of the distortion thresholds. In an audio encoding application, the distortion thresholds are based on psychoacoustic masking. The invention may use a novel approximation for calculating the total scaling values, which obtains a first term based on a corresponding distortion threshold, and obtains a second term based on a sum of the transform coefficients. Both of these terms may be obtained using lookup tables.
    Type: Grant
    Filed: November 20, 2001
    Date of Patent: September 27, 2005
    Assignee: Cirrus Logic, Inc.
    Inventors: Girish P. Subramaniam, Raghunath K. Rao
  • Patent number: 6665409
    Abstract: A method of producing reverberation effects is disclosed. A filter is implemented for modeling early acoustic reflections in response to an input signal using a first processor, the filter includes a delay buffer of a selected length and having a selected number of taps for tapping samples of corresponding amounts of delay and a summer for summing the tapped samples to generate a filter output signal. A reverberator is implemented for modeling late acoustic reflections using a second processor, the reverberator receiving the filter output and generating a plurality of output signals.
    Type: Grant
    Filed: April 7, 1999
    Date of Patent: December 16, 2003
    Assignee: Cirrus Logic, Inc.
    Inventor: Raghunath K. Rao