Abstract: Embodiments of the invention include a system and method to generate a quality rating prediction, such as MOS, of a video under test without using a second video as a reference. Instead of using a reference video, embodiments of the invention generate a pseudo reference video from measuring local impairments of the video under test. The local impairments are then accumulated to create a difference image. The difference image is then subtracted from the video under test to create the pseudo reference, to which the video under test is compared to generate the quality prediction rating. In some embodiments the local impairments may be measured by separating high frequency noise from the video under test from the video itself. Once separated, the noise is then measured and bandwidth compensated to generate the measured local impairments.

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: Systems and methods for discovering SCTP associations between devices communicating in a network are described. A method comprises monitoring packets communicated among a plurality of source and destination devices, determining a combination of source EP address, source port number, destination IP address, and destination port number that defines an association between a source device and a destination device, and resolving a combination of source and destination verification tags that further defines the association based upon the combination of EP addresses and port numbers. The method further comprises ascertaining whether a subsequently monitored packet belongs to the association based at least in part upon an element of the combination of verification tags after at least one element of the combination of EP addresses and port numbers has changed during the ongoing communication.

Abstract: Automatic generation of a frequency domain mask is achieved by drawing a reduced waveform representing frequency domain data for an input signal as a pixel map. The reduced waveform is blurred by applying a user selected frequency offset, and from the blurred waveform data points are selected to generate upper and lower limits. The selected upper limit data points form an upper limit mask and the lower limit data points form a lower limit mask. When the upper and lower limit data masks are combined and translated back to frequency/amplitude units from the pixel map, they form an envelope mask.

Abstract: A test pattern for evaluating L/R crosstalk extinction ratio in a stereoscopic 3D system has a strip of one characteristic—polarization, white, color—associated with a plurality of calibrated chips in a left eye image and a strip of a contrasting characteristic—orthogonal polarization, white, contrasting color—associated with a plurality of calibrated chips in a right eye image such that, when the two images are superimposed, the strip of one image overlays the calibrated chips of the other image. By alternately occluding one eye while observing the superimposed image with the other eye, a portion of the strip of the occluded eye image appears across the chips of the viewing eye image when there is crosstalk. The extinction ratio value associated with the chip of the viewing eye image that most closely matches the portion of the strip from the occluded eye image is an estimate of the L/R crosstalk.

Abstract: A flexible timebase for eye diagrams uses a stable free running oscillator as a sample clock for equivalent time sampling of an input serial digital signal and of a reference signal derived from a subdivided recovered clock of the input serial digital signal. The reference signal samples are provided to a digital phase-locked loop that provides the flexible timebase to an eye pattern generator. The eye pattern generator accumulates the input serial digital signal samples at times corresponding to the reference signal samples to produce the eye diagram. A linear phase detector in the digital phase locked loop converts the reference signal samples to a complex signal using a Hilbert transform and then to a linear ramp of phase values using a CORDIC algorithm with arctangent lookup table. The digital phase-locked loop feedback is subtracted from the linear ramp to provide the input to the loop filter.

Abstract: Embodiments of the present invention comprise methods and systems for detecting and locating skipped frames in a test video sequence in relation to a reference video sequence. Some embodiments comprise identifying pairs of temporally aligned reference and test segments. An alignment offset and freeze-frame count associated with each segment pair is received and used to calculate a number of skipped frames between a first segment pair and a second segment pair, the second segment pair being temporally subsequent to the first segment pair. In some embodiments, a number of skipped frames between the first segment pair and the second segment pair is determined by calculating a segment offset between the two segment pairs and subtracting the segment offset value from the sum of the number of freeze frames associated with the first segment pair and all temporally intervening segment pairs between the first segment pair and the second segment pair.

Abstract: A system and method is provided enabling identification of different PN offsets values for CDMA signals without access to a GPS signal, such as when making measurements within indoor environments. When a timing reference, such as that provided by a GPS signal, is lost, the frame boundary timestamp of the CDMA signal itself is used. The parameters of the strongest available PN offset are used. The timing error is determined and the new timing reference timestamp is estimated. The strongest PN is used as the time reference and tau is corrected for. In further embodiments, a user may be able to provide identifying information allowing the estimated timing reference timestamp to be determined even when a GPS signal was never established for providing an initial timing reference.

Abstract: Embodiments of the present invention comprise methods, systems, and apparatus for multi-domain markers.

Abstract: Aspects of the present invention are related to systems and methods for removing spikes and/or speckle noise from a digital signal. In some embodiments of the present invention, an input signal is filtered according to a first low pass filter. The low pass filtered signal, also considered a first local-mean signal, is subtracted from the input signal, thereby producing an AC signal. A maximum of a first region associated with the AC signal and a maximum of a second region associated with the AC signal are determined. When the maximum of the first region and the maximum of the second region meet a comparison criterion, coefficients for a second low pass filter are determined. The input signal is filtered according to the second low pass filter, thereby producing a second local-mean signal, and a second AC signal is produced by subtracting, from the input signal, the second local-mean signal.

Abstract: A frequency mask trigger having frequency selective amplitude discrimination capability is provided for triggering when selected frequency components of an input signal fail to reach a desired power level. A frame of digital data representing an input signal is transformed into a frequency spectrum having at least one frequency bin, each frequency bin having a power amplitude value. Each power amplitude value is compared to an upper lower reference power levels and a lower reference power level. A trigger signal is generated when the power amplitude value in any frequency bin is above the lower reference power level and below the upper reference power level for a specified time duration.

Abstract: An enhanced impulse response measurement for a pulsed frequency modulation (FM) radar signal provides a more accurate measurement of the amplitude of a secondary response relative to the amplitude of a main response. The pulsed FM radar signal is sampled to produce a time-domain sample record. The sample record is windowed to produce a windowed sample record. The windowed sample record is transformed into a frequency-domain spectrum. The spectrum is multiplied with the complex conjugate of a frequency-domain estimate of a transmitted pulsed FM radar signal to produce a de-spreaded pulse. The de-spreaded pulse is transformed into the time domain to produce a measurement of the impulse response having a main response and a secondary response. The amplitude of the secondary response is corrected to eliminate errors caused by the windowing.

Abstract: A system and method for performing wide-band spectral analysis of transient signals using a real-time spectrum analyzer (RTSA). A frequency window is selected for RTSA acquisition, the frequency window being narrower in bandwidth than the frequency spectrum of interest. An RTSA is successively tuned to a plurality of different frequencies within the frequency spectrum of interest, where such successive tuning is controlled based on a characteristic of the signal. The RF signal is received, and, for each of the plurality of different frequencies, power data is acquired for the signal in a band centered on the frequency and having a bandwidth equal to that of the frequency window. A representation of the frequency spectrum of interest is then constructed from the power data acquired during the successive tunings of the RTSA.

Abstract: A waveform display apparatus that can display a waveform in a desired position even when an internal reference mode is switched to an external reference mode. The internal and external reference modes are switched with a reference select button 60. A user operates a phase adjustment knob 64 while watching a display 54 to adjust a phase relationship between an external reference video signal and a video signal under test. When the phase relationship becomes proper an offset save button 66 is pressed to store the phase offset at the situation in a memory 56. A CPU 30 reads out the phase offset according to needs such as the waveform display apparatus is turned on, etc. to control a phase adjustment circuit 44 for adjusting the phase relationship between the external reference video signal and the video signal under test.

Abstract: A test and measurement instrument including an oscillator configured to generate a periodic signal; a mixer configured to mix an input signal with the periodic signal to generate a frequency-shifted signal; a trigger system configured to generate a trigger signal; a phase detector configured to sense a phase between the trigger signal and the periodic signal; and a controller configured to adjust processing of the frequency-shifted signal in response to the phase.

Abstract: This invention relates to a system and method of monitoring, by establishing end to end loopback testing across one or more networks with dissimilar transport technologies. The system allows for connection in loopback mode from a standard interface on a test device to a media adaptor located on an IP-based access network, such as a standard multimedia terminal adapter (“MTA”). End-to-End Quality of service delivered over the transmit and receive path can thus be monitored. Loopback tests are initiated from designated endpoints on the network and made operational by attaching a tag to a telephone number, to allow the gateway to signal connection mode to a call agent.

Abstract: System and method for automatically detecting nodes, components and interfaces in a network. A preferred embodiment comprises detecting nodes in a network, wherein the nodes are coupled to a network controller, comprises identifying ports for the network controller, capturing messages received by the network controller at the ports, parsing the messages to identify a node address parameter, wherein the node address parameter uniquely identifies the node to the network controller, and if the node address parameter has not been previously identified, adding a new entry to a node database.

Abstract: A method of determining configuration parameters of a mobile network topology for testing and monitoring purposes at an interface (Iub) located between a first node and a second node of the mobile network where between the first and the second node there exist several channels includes finding the channel having signaling information, analyzing signaling information to determine the configuration parameters, updating the configuration parameters dynamically, and performing a monitoring activity or test scenario based on the configuration parameters.