Hi Mason,
The difference between Simulink and MATLAB AGC outputs likely boils down to three things:
- Data Check: Make sure the data you use in both environments is loaded and formatted identically.
- AGC Settings Match? Double-check that the AGC properties in your MATLAB script are exactly the same as those used in the Simulink block.
- Simulink Extras? Your Simulink model might have additional processing steps affecting the AGC output. Consider these if present
I have tried making some changes in your code, you work on this, I am sure you'll able to figure it out.
- Move AGC Object Creation: Instead of creating a new agc object in each loop iteration, create it outside the loop with desired properties (e.g., "AdaptationStepSize", "DesiredOutputPower").
- Loop Through Data: Within the loop, simply apply the existing agc object to each data segment to achieve AGC and process/plot the results.
- Persistent State: This approach allows the agc object's gain value to adapt continuously across the entire data sequence, mimicking the Simulink block's behavior.
- Optional Release: Releasing the object after the loop is good practice for memory management (optional).
load('out.mat');
% AGC object creation
agc = comm.AGC('AdaptationStepSize', 0.01, ...
'DesiredOutputPower', 0.9, ...
'AveragingLength', 128, ...
'MaxPowerGain', 10);
% Loop through the data
for ii = 1:size(need_gain_data, 3)
txSig = need_gain_data(:,:,ii);
% Apply AGC
rxSig = agc(txSig);
% Plot constellation diagram
figure(1)
scatter(real(txSig(1:end)), imag(txSig(1:end)), '*');
hold on
scatter(real(rxSig(1:end)), imag(rxSig(1:end)), 'or');
title('Constellation Diagram (Before & After AGC)');
xlabel('Real Part');
ylabel('Imaginary Part');
legend('Input of AGC', 'Output of AGC');
hold off;
% Additional processing or analysis (optional)
% ...
end
% Release the object after the loop (optional)
release(agc);
