NormalizedFrequency

Assume normalized frequency values
Specify whether the frequency values are normalized. If you
set this property to true , the object assumes that
frequency values are normalized (in the [1 1] range). The default
is false . If you set this property to false ,
the object assumes that frequency values are measured in Hertz.

SampleRate

Sample rate of input signal
Specify the sample rate of the input signal, in samples per second, as a doubleprecision,
positive scalar. The default is 1e6 samples per second. This property
applies when you set the NormalizedFrequency property to
false .

MainChannelFrequency

Main channel center frequency
Specify the main channel center frequency as a doubleprecision
scalar. The default is 0 Hz.
When you set the NormalizedFrequency property to
true , you must specify the center frequency as a normalized value between
1 and 1 .
When you set the NormalizedFrequency property to
false , you must specify the center frequency in Hertz. The object measures
the main channel power in the bandwidth that you specify in the MainMeasurementBandwidth
property. This measurement is taken at the center of the frequency that you specify in the
MainMeasurementBandwidth property.

MainMeasurementBandwidth

Main channel measurement bandwidth
Specify the main channel measurement bandwidth as a doubleprecision,
positive scalar. The default is 50e3 Hz.
When you set the NormalizedFrequency property to
true , you must specify the measurement bandwidth as a normalized value
between 0 and 1 .
When you set the NormalizedFrequency property to
false , you must specify the measurement bandwidth in Hertz. The object
measures the main channel power in the bandwidth that you specify in the MainMeasurementBandwidth property. This measurement is taken at the
center of the frequency that you specify in the MainChannelFrequency property.

AdjacentChannelOffset

Adjacent channel frequency offsets
Specify the adjacent channel offsets as a doubleprecision scalar
or as a row vector comprising frequencies that define the location
of adjacent channels of interest. The default is [100e3
100e3] Hz.
When you set the NormalizedFrequency property to
true , you must specify normalized frequency offset values between
1 and 1 . When you set the NormalizedFrequency property to false , you must specify
frequency offset values in Hertz. The offset values indicate the distance between the main
channel center frequency and adjacent channel center frequencies. Positive offsets indicate
adjacent channels to the right of the main channel center frequency. Negative offsets indicate
adjacent channels to the left of the main channel center frequency.

AdjacentMeasurementBandwidth

Adjacent channel measurement bandwidths
Specify the measurement bandwidth for each adjacent channel. The default is the scalar,
50e3 . The object assumes that each adjacent bandwidth is centered at the
frequency defined by the corresponding frequency offset. You define this offset in the
AdjacentChannelOffset property.
Set this property to a doubleprecision scalar or row vector of length equal to the number of
specified offsets in the AdjacentChannelOffset
property.
When you set this property to a scalar, the object obtains all adjacent channel power
measurements within equal measurement bandwidths. When you set the NormalizedFrequency property to
true , you must specify normalized bandwidth values between
0 and 1 . When you set the NormalizedFrequency property to
false , you must specify the adjacent channel bandwidth values in
Hertz.

MeasurementFilterSource

Source of the measurement filter
Specify the measurement filter source as one of None 
Property . The default is None . When you set this
property to None the object does not apply filtering to obtain ACPR
measurements. When you set this property to Property , the object applies a
measurement filter to the main channel before measuring the average power. Each of the
adjacent channel bands also receives a measurement filter . In this case, you specify the
measurement filter coefficients in the MeasurementFilter property.

MeasurementFilter

Measurement filter coefficients
Specify the measurement filter coefficients as a doubleprecision row vector containing the
coefficients of an FIR filter in descending order of powers of z. Center the response of the
filter at DC. The ACPR object automatically shifts and applies the filter response at each of
the main and adjacent channel center frequencies before obtaining the average power
measurements. The internal filter states persist and clear only when you call the reset
method. This property applies when you set the MeasurementFilterSource
property to Property . The default is 1 , which is an
allpass filter that has no effect on the measurements.

SpectralEstimation

Spectral estimation control
Specify the spectral estimation control as one of Auto  Specify
frequency resolution  Specify window parameters .
The default is Auto .
When you set this property to Auto , the object
obtains power measurements with a Welch spectral estimator with zeropercent
overlap, a Hamming window, and a segment length equal to the length
of the input data vector. In this setting, the spectral estimator
set should achieve the maximum frequency resolution attainable with
the input data length.
When you set this property to Specify frequency resolution , you specify the
desired spectral frequency resolution, in normalized units or in Hertz, using the FrequencyResolution property. In
this setting, the object uses the value in the FrequencyResolution property to automatically compute the size of the spectral
estimator data window.
When you set this property to Specify window parameters , several spectral
estimator properties become available so that you can control the Welch spectral estimation
settings. These properties are: SegmentLength , OverlapPercentage , Window, and SidelobeAttenuation. Sidelobe
attenuation applies only when you set the Window property to Chebyshev .
When you set this property to Specify window parameters ,
the FrequencyResolution property does not apply,
and you control the resolution using the above properties.

SegmentLength

Segment length
Specify the segment length, in samples, for the spectral estimator as a numeric, positive,
integer scalar. The default is 64 . The length of the segment allows you to
make tradeoffs between frequency resolution and variance in the spectral estimates. A long
segment length results in better resolution. A short segment length results in more averaging
and a decrease in variance. This property applies when you set the SpectralEstimation property to
Specify window parameters .

OverlapPercentage

Overlap percentage
Specify the percentage of overlap between each segment in the spectral estimator as a
doubleprecision scalar in the [0 100] interval. This property applies when
you set the SpectralEstimation property to
Specify window parameters . The default is 0
percent.

Window

Window function
Specify a window function for the spectral estimator as one of Bartlett 
BartlettHanning  Blackman 
BlackmanHarris  Bohman  Chebyshev
 Flat Top  Hamming  Hann 
Nuttall  Parzen  Rectangular 
Triangular . The default is Hamming . A Hamming window
has 42.5 dB of sidelobe attenuation. This attenuation may mask spectral
content below this value, relative to the peak spectral content. Choosing different windows
allows you to make tradeoffs between resolution and sidelobe attenuation. This property
applies when you set the SpectralEstimation property to
Specify window parameters .

SidelobeAttenuation

Sidelobe attenuation for Chebyshev window
Specify the sidelobe attenuation, in decibels, for the Chebyshev window function as a
doubleprecision, nonnegative scalar. The default is 100 dB. This property
applies when you set the SpectralEstimation property to
Specify window parameters and the Window property to Chebyshev .

FrequencyResolution

Frequency resolution
Specify the frequency resolution of the spectral estimator as
a doubleprecision scalar. The default is 10625 Hz.
When you set the NormalizedFrequency property to true , you must specify the
frequency resolution as a normalized value between 0 and
1 . When you set the NormalizedFrequency property to
false , you must specify the frequency resolution in Hertz. The object uses
the value in the FrequencyResolution property to
calculate the size of the data window used by the spectral estimator. This property applies
when you set the SpectralEstimation property to
Specify frequency resolution .

FFTLength

FFT length
Specify the FFT length that the Welch spectral estimator uses
as one of Next power of 2  Same as segment
length  Custom . The default is Next
power of 2 .
When you set this property to Custom , the CustomFFTLength property becomes
available to specify the desired FFT length.
When you set this property to Next power of 2 ,
the object sets the length of the FFT to the next power of 2. This
length is greater than the spectral estimator segment length or 256 ,
whichever is greater.
When you set this property to Same as segment length ,
the object sets the length of the FFT. This length equals the spectral
estimator segment length or 256 , whichever is greater.

CustomFFTLength

Custom FFT length
Specify the number of FFT points that the spectral estimator uses as a numeric, positive,
integer scalar. This property applies when you set the FFTLength property to Custom . The default is
256 .

MaxHold

Maxhold setting control
Specify the maximum hold setting. The default is false .
When you set this property to true , the object
compares two vectors. One vector compared is the current estimated
power spectral density vector (obtained with the current input data
frame). The object checks this vector against the previous maximumhold
accumulated power spectral density vector, (obtained at the previous
call to the step method). The object stores the maximum
values at each frequency bin and uses them to compute average power
measurements. You clear the maximumhold spectrum by calling the reset method
on the object. When you set this property to false ,
the object obtains power measurements using instantaneous power spectral
density estimates. This property is tunable.

PowerUnits

Power units
Specify power measurement units as one of dBm  dBW  Watts .
The default is dBm .
When you set this property to dBm , or dBW ,
the step method outputs ACPR measurements in a dBc
scale (adjacent channel power referenced to main channels power).
If you set this property to Watts , the step method
outputs ACPR measurements in a linear scale.

MainChannelPowerOutputPort

Enable main channel power measurement output
When you set this property to true , the step method outputs the main channel power measurement. The default is
false . The main channel power is the power of the input signal measured in
the band that you define with the MainChannelFrequency and
MainMeasurementBandwidth
properties. The step method returns power measurements in
the units that you specify in the PowerUnits property.

AdjacentChannelPowerOutputPort

Enable adjacent channel power measurements output
When you set this property to true , the step method outputs a vector of adjacent channel power measurements. The default
is false . The adjacent channel powers correspond to the input signal's
power measured in the bands that you define with the AdjacentChannelOffset and
AdjacentMeasurementBandwidth properties. The step method returns power measurements in the units that you specify in the
PowerUnits property.
