We report on 80-Gb/s transmission over 106 km of standard-fiber (D = 16 ps/km/nm) using midspan spectral inversion. The optical phase conjugated signal is generated by four-wave mixing in a semiconductor optical amplifier (SOA). The SOA is implemented in a Sagnac-interferometer in order to achieve an efficient continuous-wave-pump suppression. Accompanying simulations show, that at 80 Gb/s, the transmission distance can hardly be enhanced due to the residual pulse broadening by second-order dispersion.