Based on my understanding, it seems that you are seeking an alternative solution to the varlms function, which has been removed in MATLAB R2022a. However, you can achieve the equivalent functionality by utilizing either the comm.LinearEqualizer or comm.DecisionFeedback objects with the LMS Adaptive Algorithm. By adjusting the step size with each iteration, you can achieve the desired behavior. I have provided a sample code snippet below that demonstrates the usage of comm.LinearEqualizer with a variable step:
% Define the channel and transmit signal
channel = [0.9 0.2 0.1] % Example channel coefficients
txSignal = randi([0 1], 1000, 1); % Random binary transmit signal.
% Apply the channel to the transmit signal
rxSignal = filter(channel, 1, txSignal);
%Create a linear equalizer object
equalizer = comm.LinearEqualizer('Algorithm', 'LMS', 'StepSize', 0.01, 'Constellation', [0 1]);
for i = 1:3
% Update the step size for each iteration
stepSize = 0.01 + 0.001 * i; % Example of a variable step size
% Set the step size in the equalizer object
equalizer.StepSize = stepSize;
% Perform equalization for the current symbol
[eqSignal, error] = equalizer(rxSignal, txSignal);
% Plot the original and equalized signals
figure;
subplot(2, 1, 1);
stem(txSignal, 'filled');
title('Original Transmit Signal');
subplot(2, 1, 2);
stem(eqSignal, 'filled');
title('Equalized Signal');
end
% Display the equalizer object properties
equalizer
Also please refer to these links for further information -
I hope the suggestions help you address your requirements.
