DAMIAN,I have found that if i select convert noise bin(the noise that overlaps the signal will be converted to sampled signal,the sampled signal power will be added ),the osnr and snr measured by wdm analyzer will be higher than not be selected.I think that is not the exactly right osnr and snr.how about electrical carrier analyzer?is it measured the right SNR if i selected convert noise bin,since i am interested in the snr in electrical domain.thank you !