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30 Gbit/s (5 Gsymbol/s) 64-QAM real-time transmission over 60 km SSMF without any dispersion compensation has been experimentally demonstrated for the first time. Intersymbol interference caused by the limited frequency bandwidth of electrical components in the transmitter and receiver was compensated using a pre-equalisation technique based on electronic digital processing. Phase-noise cancelling based on a polarisation-multiplexed pilot-carrier was employed, allowing use of a light source with a linewidth as large as 200 kHz. A bit error rate of 10 -4 was achieved even after SSMF transmission without using error correction.