Patents by Inventor Ramanujeya Lakshminarayan Narahari

Ramanujeya Lakshminarayan Narahari 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).

  • Time-domain mechanism for computing error vector magnitude of OFDM signals
    Patent number: 9667390
    Abstract: A mechanism for determining an error vector magnitude EVMTD for a signal transmitted by a device under test (DUT). A receiver (typically an RF signal analyzer) produces a baseband signal in response to the signal transmission. An OFDM input signal (derived from the baseband signal) is accessed from memory. The OFDM input signal includes a sequence of time-domain OFDM input symbols. A reference signal is accessed from the memory. The reference signal includes a sequence of time-domain OFDM reference symbols. EVMTD is computed in the time domain based on a time-domain difference signal, i.e., a time-domain difference between the sequence of time-domain OFDM input symbols and the sequence of time-domain OFDM reference symbols. The error vector magnitude EVMTD is determined without transforming the sequence of time-domain OFDM input symbols to the frequency domain. The error vector magnitude EVMTD is related to a standard-defined composite EVM by a scalar multiple.
    Type: Grant
    Filed: April 17, 2014
    Date of Patent: May 30, 2017
    Assignee: NATIONAL INSTRUMENTS CORPORATION
    Inventors: I. Zakir Ahmed, Craig E. Rupp, Ramanujeya Lakshminarayan Narahari
  • Time-Domain Mechanism for Computing Error Vector Magnitude of OFDM Signals
    Publication number: 20150304075
    Abstract: A mechanism for determining an error vector magnitude EVMTD for a signal transmitted by a device under test (DUT). A receiver (typically an RF signal analyzer) produces a baseband signal in response to the signal transmission. An OFDM input signal (derived from the baseband signal) is accessed from memory. The OFDM input signal includes a sequence of time-domain OFDM input symbols. A reference signal is accessed from the memory. The reference signal includes a sequence of time-domain OFDM reference symbols. EVMTD is computed in the time domain based on a time-domain difference signal, i.e., a time-domain difference between the sequence of time-domain OFDM input symbols and the sequence of time-domain OFDM reference symbols. The error vector magnitude EVMTD is determined without transforming the sequence of time-domain OFDM input symbols to the frequency domain. The error vector magnitude EVMTD is related to a standard-defined composite EVM by a scalar multiple.
    Type: Application
    Filed: April 17, 2014
    Publication date: October 22, 2015
    Applicant: NATIONAL INSTRUMENTS CORPORATION
    Inventors: I. Zakir Ahmed, Craig E. Rupp, Ramanujeya Lakshminarayan Narahari