Hi Sulaiman,
Once you have the code words, that are generated first by the type of code you are using and the number of users, you can code each users spectral content by assigning each bit of the code word a wavelength. In our OptiSystem example, the range of wavelengths goes from [1549 1549.5 1550 1550.5 1551 1551.5 1552 1552.5] nm. You will notice 8 wavelengths for a code word of length 8.
Now assigning the rule that a bit value of 1 means the user’s signal will contain that wavelength spectral content, we can place four fiber bragg gratings to create stop pass filters for the undesired spectrum (bit values equal to 0). From Hadamard coding, there will always be 4 zeros in every code word.
I have attached a picture of the 7 users and their code words following Hadamard coding.
Regards
