We successfully demonstrate 5.35-Gb/s upstream transmission over 20-km standard single-mode fiber using an ultra-narrow spectrum-sliced incoherent light source and a reflective semiconductor optical amplifier (RSOA) without any dispersion compensation. The offset optical filtering and transmitter de-emphasis are exploited to reduce the excess intensity noise of the light source and to overcome the bandwidth limitation of the 1.4-GHz-bandwidth RSOA, respectively. Thanks to these two techniques and narrow linewidth of the source, we achieve the uncorrected bit-error rate of <10(-3) after the transmission. The acceptable range of RSOA injection power is also investigated through experiment.