How to generate a .iq file from i q data in matlab?

How do i generate a .iq file from the i q data from a matlab script exactly? Any help will be appreciated.

[Walter Roberson]

https://dl.cdn-anritsu.com/en-us/test-measurement/ohs/10450-00078A/MS2085A-89A_Site_Master_Help/iq-cap-stream.39.3.html

[Eric]

Do you have example matlab code?

[Walter Roberson]

No, and I do not see any code posted anywhere for that purpose.

I find MATLAB code for a different .iq file format at https://pysdr.org/content/iq_files.html

Answer 1

[Jaimin]

Hi @Eric

To generate a “.iq” file in binary format from IQ data in MATLAB, you need to follow these steps:

1. Prepare Your IQ Data
2. Open a File for Writing
3. Write the Data
4. Close the File

To open a file, write data to it, and then close it, you can utilise the “fopen”, “fwrite”, and “fclose” functions respectively.

Kindly refer to the following MATLAB script for understanding. (This script assumes you want to write the IQ data in a simple interleaved binary format.)

% Example IQ data
I = [0.1, 0.2, 0.3, 0.4]; % In-phase component
Q = [0.5, 0.6, 0.7, 0.8]; % Quadrature component

% Combine into complex format
IQ_data = I + 1i*Q;

% Open a file for binary writing
fileID = fopen('output.iq', 'wb');

% Check if the file opened successfully
if fileID == -1
    error('Failed to open the file.');
end

% Write the IQ data to the file
% Here, we assume single precision (32-bit) for both I and Q components
fwrite(fileID, [real(IQ_data); imag(IQ_data)], 'float32');

% Close the file
fclose(fileID);

disp('IQ data has been written to output.iq');

The script uses “float32” to represent each I and Q component. Adjust the data type as needed (e.g., “float64” for double precision).

For more information about “fopen”, “fwrite” and “fclose” kindly refer following MathWorks Documentation.

fopen: https://www.mathworks.com/help/matlab/ref/fopen.html

fwrite: https://www.mathworks.com/help/matlab/ref/fwrite.html

fclose: https://www.mathworks.com/help/matlab/ref/fclose.html

I hope this will be helpful.

[Walter Roberson]

@Eric earlier asked a similar question but phrased it as being related to aaronia rtsa suite. That makes it more likely that the file format being referred to is the one described in the link I posted above. But it is certainly not clear which file format Eric requires.