Time varying gain control
TimeVaryingGain object applies a time varying
gain to input signals. Time varying gain (TVG) is sometimes called
automatic gain control (AGC).
To apply the time varying gain to the signal:
Define and set up your time varying gain controller. See Construction.
step to apply the time
varying gain according to the properties of
The behavior of
step is specific to each object in
Starting in R2016b, instead of using the
H = phased.TimeVaryingGain creates a time
varying gain control System object,
object applies a time varying gain to the input signal to compensate
for the signal power loss due to the range.
H = phased.TimeVaryingGain( creates
H, with each specified property Name
set to the specified Value. You can specify additional name-value
pair arguments in any order as (
Source of range losses
Specify the source of range losses as either
Loss at each input sample range
Specify the loss due to range as a vector — elements correspond to the samples in the input signal. Units are in dB.
Loss at reference range
Specify the loss at a given reference range as a scalar. Units are in dB.
|step||Apply time varying gains to input signal|
|Common to All System Objects|
Create System object with same property values
Expected number of inputs to a System object
Expected number of outputs of a System object
Check locked states of a System object (logical)
Allow System object property value changes
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')
 Edde, B. Radar: Principles, Technology, Applications. Englewood Cliffs, NJ: Prentice Hall, 1993.
 Skolnik, M. Introduction to Radar Systems, 3rd Ed. New York: McGraw-Hill, 2001.
Usage notes and limitations:
See System Objects in MATLAB Code Generation (MATLAB Coder).