The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 30, 2017
Filed:
Apr. 17, 2014
National Instruments Corporation, Austin, TX (US);
I. Zakir Ahmed, Bangalore, IN;
Craig E. Rupp, Ames, IA (US);
Ramanujeya Lakshminarayan Narahari, Bangalore, IN;
NATIONAL INSTRUMENTS CORPORATION, Austin, TX (US);
Abstract
A mechanism for determining an error vector magnitude EVMfor 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. EVMis 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 EVMis determined without transforming the sequence of time-domain OFDM input symbols to the frequency domain. The error vector magnitude EVMis related to a standard-defined composite EVM by a scalar multiple.