Abstract: A real-time trigger figure-of-merit indicator for test and measurement instruments provides an indication of how close a signal-under-test is to satisfying a relevant trigger condition. The indicator includes a first marker that indicates a real-time trigger figure-of-merit that is calculated based on digital samples that represent the signal-under-test, and a second marker that indicates a level that the figure-of-merit must exceed in order for a trigger event detector to detect a trigger event and generate a trigger signal. Thus, by observing the indicator, a user may easily ascertain how close a signal-under-test is to satisfying the relevant trigger condition without requiring the instrument to actually trigger.
Abstract: A method of evaluating perceptual visual quality (PVQ) of compressed video bit streams in the H.262 or H.264 formats without performing block transforms or prediction decodes I-frames within a group of pictures (GOP). DC and AC coefficients are determined for selected macroblocks within a selected one of the I-frames. Based upon the DC and AC coefficients, the PVQ is calculated.
Abstract: The present invention is directed to a display for easily understanding time changes of communication conditions of channels using a plurality of sub-carriers. Layers corresponding to the plurality of channels are displayed along the time base in such a manner that width of each layer is determined in accordance with the number of sub-carriers used for each channel at any given time. Additionally, colors or patterns of each layer may be modified in accordance with modulation types or power levels of the corresponding layer. The relationship between colors or patterns of the layer and modulation types or power levels is displayed.
Abstract: Embodiments of this invention include a protocol sensitive visual navigation apparatus, and associated methods, for navigating and relating different protocol levels of a protocol. A test and measurement instrument can include the protocol sensitive visual navigation apparatus, which can facilitate analyzing, searching, and measuring various aspects of the different protocol layers and cross-correlating items from one protocol layer to another protocol layer. The type and characteristics of the analysis is informed by a selected protocol layer. Physical layer signals or events can be correlated to protocol level information, thereby increasing an understanding of the overall protocol and associated protocol layers and events.
Type:
Application
Filed:
November 16, 2011
Publication date:
May 16, 2013
Applicant:
TEKTRONIX, INC.
Inventors:
Keith D. RULE, Michael J. WADZITA, Walter R. STRAND
Abstract: Video data packets transmitted through a wireless network are captured by a network monitoring system. Video data sessions are detected from the video data packets. Key parameters are identified within the video data packets, such as video bit rate, resent or failed video packets, and video session duration. A Quality of Experience (QoE) is determined for some or all users associated with the video sessions based upon the key parameters. A header extension is added to the video data packets by a transcoding system. The header extension includes data associated with original and transcoded video data packets. The network monitoring system monitors the header extension and evaluates the effect of video transcoding upon the overall QoE for users. The monitoring system provides feedback to a transcoding policy engine based upon the effect of transcoding upon QoE.
Type:
Grant
Filed:
January 24, 2011
Date of Patent:
May 14, 2013
Assignee:
Tektronix, Inc.
Inventors:
Robert Todd Wilkinson, Aleksey G. Ivershen
Abstract: Embodiments of the present invention provide a variable inter symbol interference generator that generates a data signal having a variable amount of inter symbol interference by passing a data signal through (1) a programmable filter having an adjustable frequency response, and through (2) a fixed filter having a fixed frequency response such as a PCB trace, a length of cable, a discrete filter, or the like. By adjusting the parameters and therefore the insertion gain or loss of the programmable filter, and combining this with one or more fixed filters, a large range of continuously variable and finely tunable inter symbol interference amounts can be easily generated.
Type:
Application
Filed:
August 24, 2012
Publication date:
May 9, 2013
Applicant:
TEKTRONIX, INC.
Inventors:
James R. WASCHURA, Senthil Kumar THANDAPANI, Timothy E. SAUERWEIN
Abstract: A signal acquisition system has a signal acquisition probe having probe tip circuitry coupled to a resistive center conductor signal cable. The resistive center conductor signal cable of the signal acquisition probe is coupled to a compensation system in a signal processing instrument via an input node and input circuitry in the signal processing instrument. The signal acquisition probe and the signal processing instrument have mismatched time constants at the input node with the compensation system providing pole-zero pairs for maintaining flatness over the signal acquisition system frequency bandwidth.
Type:
Grant
Filed:
July 29, 2010
Date of Patent:
May 7, 2013
Assignee:
Tektronix, Inc.
Inventors:
Josiah A. Bartlett, Ira G. Pollock, Daniel G. Knierim, Lester L. Larson, Scott R. Jansen, Kenneth P. Dobyns, Michael Duane Stevens
Abstract: Embodiments of the present invention provide systems and methods for non-invasive, “in-service” AV delay detection and correction. These systems and methods do not modify the audio signal or the video signal, nor do they rely on any metadata to be carried with the audio signal or the video signal via the distribution path. Instead, agents located at various points along the distribution path generate very small signature curves for the audio signal and the video signal and distribute them to a manager via a separate data path other than the distribution path. The manager calculates a measured AV delay caused by the distribution path based on these signature curves, and then optionally corrects the measured AV delay by adjusting an in-line delay in the distribution path.
Abstract: Aspects of the present invention are related to methods and systems for image processing, in particular, to methods and systems for computationally efficient and robust image alignment. Initially, larger image features may be used to approximate an alignment measurement. Results of the initial measurement may be used to narrow the search range used in conjunction with higher-resolution images in subsequent alignment measurements. The narrowed search range may insure that if the alignment measurement using the fine-detail images fails, then the measured results may have the accuracy as indicated by the prior, reduced-image-based measurement.
Abstract: An apparatus and method for splitting a wide band input signal and overlaying multiple frequency bands on each path associated with one or more digitizers. All frequencies from the split signal on each path can be fed to a mixer. The local oscillator of each mixer receives a sum of signals, which can each be set to any arbitrary frequency, as long as an associated matrix determinant of coefficients is non-zero. Each oscillator signal is multiplied by a coefficient, which can represent phase and magnitude, prior to summing the oscillator signals together. Each mixer mixes a combined signal with the input, thereby generating a set of multiple overlaid frequency bands. The digitized signals are processed to substantially reconstruct the original input signal. Thus, the wide band input signal is digitized using multiple individual digitizers. In particular, a system can support two wide band signals using four digitizers of narrower bandwidth.
Abstract: Embodiments of the present invention provide enhanced methods of calibrating arbitrary waveform generators using s-parameters, and arbitrary waveform generators calibrated according to those methods. Methods are provided for calibrating a single, non-interleaved channel of an arbitrary waveform generator, calibrating multiple interleaved channels, and calibrating pairs of channels, both interleaved and non-interleaved, to generate differential signals.
Abstract: Embodiments of the present invention provide enhanced methods of calibrating arbitrary waveform generators using s-parameters, and arbitrary waveform generators calibrated according to those methods. Methods are provided for calibrating a single, non-interleaved channel of an arbitrary waveform generator, calibrating multiple interleaved channels, and calibrating pairs of channels, both interleaved and non-interleaved, to generate differential signals.
Abstract: A method of setting up a communication procedure between instances, one of which is a protocol tester that uses the method, includes the steps of selecting the instances, selecting a protocol layer for the communication procedure, selecting abstract communication interfaces for the protocol layer; selecting communication data and automatically setting up the communication procedure on the basis of the results of the selecting steps. Any of the selecting steps may be performed graphically, and parameters selected are assigned description files that are used in the setting up step.
Type:
Grant
Filed:
February 1, 2001
Date of Patent:
March 19, 2013
Assignee:
Tektronix, Inc.
Inventors:
Joerg Ehrhardt, Jens Kittan, Wolfgang Borgert
Abstract: Systems and methods for monitoring over-the-top adaptive video streaming in a network are described. In an embodiment, a method may include identifying a protocol used in the communication based, wherein the protocol may be one among a plurality of different adaptive video streaming protocols. Video sessions using a plurality of different protocols are monitored and video session data collected. User Quality of Experience (QoE) and Key QoE Indicators (KQI) are generated for the network. Network operators may access video session data to analyze initial buffering delays, rebuffering delays, bandwidth changes, and gaps during the video session.
Type:
Application
Filed:
January 12, 2012
Publication date:
March 14, 2013
Applicant:
TEKTRONIX, INC.
Inventors:
Wei Dong, Robert Todd Wilkinson, Paul Anthony Robinson
Abstract: A system, method and computer program product are disclosed for monitoring a telecommunications network that comprises a plurality of Mobility Management Entity (MME) nodes and a plurality of evolved UTRAN NodeB (eNodeB) nodes coupled by S1-MME interfaces. A Stream Control Transmission Protocol (SCTP) association identifier is assigned to an SCTP association between interconnected MME and eNodeB nodes. Specific S1-MME messages allow discovering the MME nodes and the eNodeB nodes with their network identifiers, identifying the connections between them and populating proper tables for this topology information.
Abstract: A time-interleaved RF triggering method and system on a test and measurement instrument includes an acquisition component that samples a waveform, which is converted into an amplitude, phase, frequency, in-phase (I), and quadrature (Q) waveform, any of which can be used for triggering an RF digital trigger, including triggering that uses demodulation and/or decoding of the down-converted complex IQ data samples for a given protocol. Aliasing caused by subsampled data in each of the interleaved acquisition components is cancelled out using a fractional time-shift filter.
Abstract: Coherent optical signal processing is performed in a coherent receiver (or diagnostic/testing apparatus) that converts an amplitude and/or angle-modulated optical signal into two electrical signals. A simple receiver can only detect one phase of the signal and only the polarization that is aligned with a local oscillator laser polarization. To detect both phases and both polarizations, two sets of two interferometers, one each with a ?/2 phase shift are required. Coherent optical signal processing methods, apparatus, techniques, etc. are disclosed that include individual components comprising a polarization combiner, a Savart device and photodetection apparatus with substantially reduced temperature and alignment sensitivity operating in optical communication systems and/or subsystems. The various embodiments can be used alone or in such combinations to provide improved coherent optical signal processing in a receiver.
Abstract: A method and device for measuring a signal of a die to be placed within a package is disclosed. At least one die as a Device Under Test (DUT) is mounted on a substrate and a chip-type measurement instrument is mounted on the substrate, or embedded into the substrate, wherein the instrument analyzes and/or processes the signal of the DUT and may provide stimulus signal to the DUT. The substrate having the DUT and the measurement instrument is mounted on a circuit board that has plural electrodes to be connected to the signal paths of the DUT and the instrument. An electrode is coupled to a standard interface port to provide the signal of the chip-type instrument to an external instrument.
Type:
Grant
Filed:
December 18, 2009
Date of Patent:
February 26, 2013
Assignee:
Tektronix, Inc.
Inventors:
Bart A. Mooyman-Beck, Robert J. Woolhiser, Kevin E. Cosgrove, Daniel G. Knierim