Dear sir, this is practice file, if we use coherent detection, we get I and Q component but we do not use access technique like OFDM-QAM in the transmitter so do not use at receiver as well. my problem is how to combine two signals(I/Q without using OFDM-QAM) to feed them to 3R REGENERATOR AND BER ANALYZER(because these are one input polarity modules and we have two signals from coherent detection)