Table Of Contents

MT Measure Burst Timing (G Dataflow)

Version:
    Last Modified: February 7, 2018

    Locates a burst within the input complex waveform with peaks correlating to the input ideal power curve.

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    Note  

    The upper mask, ideal power curve, and lower mask arrays must contain the same number of elements.

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    input complex waveform

    The time-aligned and oversampled complex waveform data after matched filtering and frequency offset correction.

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    t0

    Trigger (start) time of the Y array.

    Default: 0.0

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    dt

    Time interval between data points in the Y array.

    Default: 1.0

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    Y

    The complex-valued signal-only baseband modulated waveform. The real and imaginary parts of this complex data array correspond to the in-phase (I) and quadrature-phase (Q) data, respectively.

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    upper mask

    The upper mask threshold for burst power in dB.

    Default: 0

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    ideal power curve

    The best location for the power curve.

    This curve is correlated against the input complex waveform to find the peak correlation. The ideal power curve must always be located between the upper mask and the lower mask.

    Default: 0

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    lower mask

    The lower mask threshold for burst power in dB.

    Default: 0

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    error in

    Error conditions that occur before this node runs.

    The node responds to this input according to standard error behavior.

    Standard Error Behavior

    Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

    error in does not contain an error error in contains an error
    If no error occurred before the node runs, the node begins execution normally.

    If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

    If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

    Default: No error

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    impairment measurement window

    The portion of the input complex waveform that is measured for amplitude droop and crest factor. This cluster is specified relative to the start of the region delineated by the upper mask, ideal power curve, and lower mask parameters.

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    start index

    Index of the first sample of the measurement window.

    Default: 0

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    width

    Number of samples over which amplitude droop and crest factor are measured. This value must be 2 or greater.

    Default: 100

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    amplitude droop

    The amplitude droop, in dB, calculated over the specified impairment measurement window.

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    pass?

    A Boolean that determines whether the peak-correlated portion of the input complex waveform meets the upper mask and lower mask specifications.

    TRUE Indicates that all samples fall within the region defined by the upper mask and lower mask parameters.
    FALSE Indicates that all samples do not fall within the region defined by the upper mask and lower mask parameters.
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    first error sample index

    The index value of the first sample in the peak-correlated portion of the input complex waveform that falls outside of the region defined by the upper mask and lower mask parameters. This index value is an offset into the upper mask/lower mask arrays.

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    correlated burst index

    Index value of the first sample in the peak-correlated portion of the input complex waveform, in samples. This index value is relative to the start of the input complex waveform.

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    crest factor

    The measured crest factor of the power envelope calculated over the specified impairment measurement window.

    The calculation is defined as the dimensionless quantity [ 10 × log ( M a x p n / M e a n p n ]

    where p n is the power envelope of the input complex waveform.

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    error out

    Error information.

    The node produces this output according to standard error behavior.

    Standard Error Behavior

    Many nodes provide an error in input and an error out output so that the node can respond to and communicate errors that occur while code is running. The value of error in specifies whether an error occurred before the node runs. Most nodes respond to values of error in in a standard, predictable way.

    error in does not contain an error error in contains an error
    If no error occurred before the node runs, the node begins execution normally.

    If no error occurs while the node runs, it returns no error. If an error does occur while the node runs, it returns that error information as error out.

    If an error occurred before the node runs, the node does not execute. Instead, it returns the error in value as error out.

    Burst Timing

    For burst signals, burst timing refers to the location of the burst obtained by its correlation against an ideal power curve. In addition, an upper and lower mask are used to test whether the burst signal satisfies mask specifications. The following figure illustrates the ideal power curve, upper mask, and lower mask.

    This node compares the peak-correlated section with the upper mask and lower mask parameters to validate that the peak-correlated portion falls within the mask specification. Finally, the node measures and returns the amplitude droop and crest factor of the peak-correlated portion of the input complex waveform.

    Where This Node Can Run:

    Desktop OS: Windows

    FPGA: Not supported

    Web Server: Not supported in VIs that run in a web application


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