Hello Aabid,
I was trying this example (https://optiwave.com/resources/applications-resources/optical-system-digital-modulation-dpsk/) according files which you’ve attached (DPSK Step xx) and if I run the project, the output behind DPSK sequence decoder is zero (I made screen, I’ve attached screen below). Maybe the same error will be in my 32QAM project that output behind decoder is all zero.
Regards