We have analyzed a scheme using electrical prefiltering at the transmitter and electronic signal processing at the receiver to enhance the spectral efficiency of binary non-return-to-zero (NRZ) wavelength-division-multiplexed (WDM) networks consisting of typical terrestrial dispersion maps employing standard single-mode fiber (SSMF) and erbium-doped fiber amplifiers (EDFAs). Our analysis shows that up to 1.6 bits/s/Hz of spectral efficiency is achievable using this technique with orthogonal polarization launch of alternate channels in 10.7 Gb/s binary NRZ systems for transmission distances up to 800 km typically used in metropolitan optical networks.