step
System object: comm.RectangularQAMDemodulator
Namespace: comm
(Removed) Demodulate using rectangular QAM method
comm.RectangularQAMDemodulator
has been
removed. Use qamdemod
instead.
Syntax
Y = step(H,X)
Y = step(H,X,VAR)
Description
Note
Starting in R2016b, instead of using the step
method to perform the operation defined by the System object™, you can call the object with arguments, as if it were a function. For
example, y = step(obj,x)
and y = obj(x)
perform equivalent operations.
Y = step(H,X)
demodulates the input data, X
,
with the rectangular QAM demodulator System object, H
, and returns, Y
. Input
X
must be a scalar or a column vector with double or single
precision data type. When ModulationOrder
is an even
power of two and you set the BitOutput
property to
false
or, when you set the DecisionMethod
to Hard decision
and the BitOutput
property to true
, the data
type of the input can also be signed integer, or signed fixed point (fi objects).
Depending on the BitOutput
property value, output
Y
can be integer or bit valued.
Y = step(H,X,VAR)
uses soft decision demodulation and noise
variance VAR
. This syntax applies when you set the BitOutput
property to true
, the DecisionMethod
property to Approximate
log-likelihood ratio
or Log-likelihood ratio
, and the
VarianceSource
property to Input
port
. The data type of input VAR
must be double or
single precision.
Note
obj
specifies the System object on which to run this step
method.
The object performs an initialization the first time the step
method is executed. This initialization locks nontunable properties and
input specifications. For more information on changing property values, see System Design in MATLAB Using System Objects.