Abstract:

To overcome the problem which limited ability to suppress strength of PAPR(Peak To Average Power Ratio) of IPTS for optical OFDM(Orthogonal Frequency Division Multiplexing), an improved method divides the transmitting datas into D levels on the method of gradient descent, filtrating the trasmit datas layer after layer and
combining searching phase factors of each level with the IPTS technique. The simulation results show that the improved method is less complex than IPTS algorithm, and has lower PAPR than IPTS algorithm. In the 128 subcarrier OFDM system, the number of subcarriers packets V = 4, divided layer D = 2, and with the CCDF(Complementary Cumulative Distribution Function ) of 10-5, the PAPR in the improved algorithm is nearly lower 0. 5 dB than that in IPTS.

Key words: orthogonal frequency division multiplexing(OFDM), peak to average power ratio (PAPR), partial transmit sequences(PTS), complementary cumulative distribution function(CCDF)