step

System object: phased.TimeVaryingGain
Package: phased

Apply time varying gains to input signal

Syntax

Y = step(H,X)

Description

Y = step(H,X) applies time varying gains to the input signal X. The process equalizes power levels across all samples to match a given reference range. The compensated signal is returned in Y. 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 X must match the length of the loss vector specified in the RangeLoss property. Y has the same dimensionality as X.

    Note:   H 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, 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 call the release method to unlock the object.

Examples

Apply time varying gain to a signal to compensate for signal power loss due to range.

rngloss = 10:22; refloss = 16; % in dB
t = (1:length(rngloss))';
x = 1./db2mag(rngloss(:));
H = phased.TimeVaryingGain('RangeLoss',rngloss,...
    'ReferenceLoss',refloss);
y = step(H,x);

% Plot signals
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');

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