Hi all,
while designing a full duplex fiber communication link using 16 QAM facing some problem, let us consider upper left transmitter and right most receiver, I have attached a design file where I am finding the constellation point good, but when I increase the distance a little more suppose 10 km, there comes so much of noise and the constellation diagram also and the constellation point are shifted in anticlockwise direction, what may be the reason of that and my question is why I so much difference is coming when I increase the fiber length.
why the system output is so much dependent on the fiber length. I have assumed the same bit rate in pseudo random bit sequence generator (PRBS) and in the layout same, increased the sequence length to have more accurate result. please give me some suggestion to get out of this problem.
The Bit error rate analyzer also showing some kind of unexpected result, I need to mention that I may be wrong while connecting the BER analyzer. you can try modify the design also.
Thanks in advance.
With regards
.