Hi.. I have tried to create a 3 user Sac-OCDMA system using the MQC coding scheme and have accordingly created the FBGs based on the codes for the encoding and decoding sections. However, i still happen to be experiencing some issues. When any user is turned ON individually, i get a clear output, as in acceptable BER values. But if i were to turn ON all the 3 users simultaneously, i got not output what-so-ever. Any suggestion as to why that might be?