Abstract: The main researches were focused on the lossy compression of OFDM time domain signals in network of FTTdp+GDSL. In order to decrease the peak-to-average power ratio, two data compression algorithms, namely Clipping with Tail Plug and Geometric Series Companding, were proposed in this paper and were applied to the model of data compression for validation. Simulation study indicated that these two methods performed well of compressing OFDM time domain signals in the system of fiber transportation, the properties can achieve that decompression output signal noise ratio is less than 55 dB when compress ratio is 1.4∶1, and decompression output signal ratio is less than 50 dB when compress ratio is 1.75∶1.