Hi Ranjeet..
I appreciate that you uploaded these. Going by these images, I think the concept of having a midpoint threshold value is actually about the last option of the table ‘Decision Inst.’. And about the threshold value, I can see there’s a difference in the two imaged. I believe this has to do with adaptive thresholding, wherein going by the channel state the threshold values are set to minimise the BER. This varies with the modulation schemes as well. Eg. OOK has fixed point thresholding. Could you please tell me which modulation scheme has been employed in the system ?
Regards.