In this paper, effect of enhancing signal detection on improving WDM transmission performance is considered. This has been shown for systems operating at 10 Gbps with a non-return-to-zero (NRZ) modulation format. The transmission system has been built using standard transmitters and receivers operating at wavelength of 1550 nm with a standard single mode fiber. Performance of improved detected signal has been evaluated via the analysis of quality factor obtained from the detected eye diagrams and the computation of bit error rate. Numerical simulations have shown a noticeable improvement of the system bit error rate (BER) after a post processing operation on the received signal. An average factor around 30% increase in the fiber span for a BER 10-9 is reported. This improvement will allow fiber spans to increase, diminish the amount of repeaters used and thus reduce the cost of transmission systems.