System object: phased.TimeVaryingGain
Apply time varying gains to input signal
Y = step(H,X)
Y = step(H,X,L)
Starting in R2016b, instead of using the
to perform the operation defined by the System
object™, you can
call the object with arguments, as if it were a function. For example,
= step(obj,x) and
y = obj(x) perform
applies time varying gains to the input signal matrix
Y = step(
process equalizes power levels across all samples to match a given reference range. The
compensated signal is returned in
X can be
a column vector, a matrix, or a cube. The gain is applied to each column in
X independently. The number of rows in
cannot exceed the length of the loss vector specified in the
Y has the same
X can be single or double
The size of the first dimension of the input matrix can vary to simulate a changing signal length. A size change can occur, for example, in the case of a pulse waveform with variable pulse repetition frequency.
in addition, specifies the range loss,
Y = step(
L as a columns vector. Use
this argument only when you set the
RangeLossSource property to
'Input port'. The length of
L must be equal
to or greater than the number of rows of
can be single or double precision.
The object performs an initialization the first time the object is executed. This
initialization locks nontunable properties (MATLAB)
and input specifications, such as dimensions, complexity, and data type of the input data.
If you change a nontunable property or an input specification, the System
object issues an error. To change nontunable properties or inputs, you must first
release method to unlock the object.
Apply time varying gain to a signal to compensate for signal power loss due to range.
First, create a signal with range loss. Set the reference loss to 16 dB.
rngloss = 10:22; refloss = 16; t = (1:length(rngloss))'; x = 1./db2mag(rngloss(:));
Then add gain to compensate for range loss.
gain = phased.TimeVaryingGain('RangeLoss',rngloss,'ReferenceLoss',refloss); y = gain(x);
Plot the signal with loss and the compensated signal.
tref = find(rngloss==refloss); stem([t t],[abs(x) abs(y)]) hold on stem(tref,x(tref),'filled','r') xlabel('Time (s)'); ylabel('Magnitude (V)') grid on legend('Before time varying gain','After time varying gain',... 'Reference range')