Package: comm
Apply memoryless nonlinearity to input signal
The MemorylessNonlinearity
object applies a
memoryless nonlinearity to a complex, baseband signal. You can use
the object to model radio frequency (RF) impairments to a signal at
the receiver.
To apply memoryless nonlinearity to the input signal:
Define and set up your memoryless nonlinearity object. See Construction.
Call step
to apply memoryless
nonlinearity according to the properties of comm.MemorylessNonlinearity
.
The behavior of step
is specific to each object in
the toolbox.
H = comm.MemorylessNonlinearity
creates
a memoryless nonlinearity System object™, H
.
This object models receiver radio frequency (RF) impairments.
H = comm.MemorylessNonlinearity(
creates
a memoryless nonlinearity object, Name
,Value
)H
, with each
specified property set to the specified value. You can specify additional
namevalue pair arguments in any order as (Name1
,Value1
,...,NameN
,ValueN
).

Method used to model nonlinearity Specify the nonlinearity method as one of 

Scale factor applied to input signal Specify the scale factor in decibels. The object applies this
factor to the input signal as a real scalar value of double or singleprecision
data type. The default is 

Linear gain applied to output signal Specify the linear gain (in decibels) that the object applies
to the output signal as a real scalar value of double or singleprecision
data type. The default is 

Thirdorder input intercept point Specify the thirdorder input intercept point (in decibels relative
to a milliwatt) as a real scalar value of double or singleprecision
data type. The default is 

AM/PM conversion factor Specify the AM/PM conversion factor (in degrees per decibel)
as a real scalar value of double or singleprecision data type. The
default is 

AM/AM conversion parameters Specify the AM/AM conversion parameters that the object uses
to compute the amplitude gain for an input signal as a real vector
of double or singleprecision data type. The default is This property applies when you set the When you set the 

AM/PM conversion parameters Specify the AM/PM conversion parameters used to compute the
phase change for an input signal as a real vector of double or singleprecision
data type. The default is This property applies when you set the When you set the 

Lower input power limit Specify the minimum input power (in decibels relative to a milliwatt)
for which AM/PM conversion scales linearly with input power value.
The default is 

Upper input power limit Specify the maximum input power (in decibels relative to a milliwatt)
for which AM/PM conversion scales linearly with input power value.
The default is 

Scale factor applied to output signal Specify the scale factor (in decibels) that the object applies
to the output signal as a real scalar value of double or singleprecision
data type. The default is 

Smoothness factor Specify the smoothness factor as a real scalar value of double
or singleprecision data type. The default is 

Output saturation level Specify the output saturation level as a real scalar value of
double or singleprecision data type. This property applies when
you set the 
clone  Create memoryless nonlinearity object with same property values 
getNumInputs  Number of expected inputs to step method 
getNumOutputs  Number of outputs from step method 
isLocked  Locked status for input attributes and nontunable properties 
release  Allow property value and input characteristics changes 
step  Apply memoryless nonlinearity to input signal 
Apply "Saleh model" nonlinearity to a 16QAM signal.
% Create 16QAM modulator hMod = comm.RectangularQAMModulator('ModulationOrder',16,... 'NormalizationMethod','Average power', 'AveragePower',1e2); % Create Memoryless Nonlinearity System object hNonlin = comm.MemorylessNonlinearity('Method', 'Saleh model'); % Generate modulated symbols modData = step(hMod, randi([0 15], 1000, 1)); % Apply Nonlinearity model and plot the result y = step(hNonlin, modData); scatterplot(y)
This object implements the algorithm, inputs, and outputs described on the Memoryless Nonlinearity block reference page. The object properties correspond to the block parameters.