Improved ACE and ICF low complexity joint algorithm to reduce PAPR of CO-OFDM system

Active constellation expansion(ACE) and iterative clipping and filtering(ICF) are simple and effective techniques for reducing the peak-to-average ratio(PAPR) in coherent optical orthogonal frequency division multiplexing(CO-OFDM) systems, but effective PAPR suppression requires a lot of iterations. To overcome this shortcoming, a joint algorithm based on improved active constellation expansion(IACE) and ICF(IACE-ICF) is proposed. The simulation results show that at the complementary cumulative distribution function(CCDF) of 10-4, the PAPR of IACE-ICF(G=4, iter=4) algorithm is optimized by 1.507 d B, 1.13 d B and 0.204 d B compared with that of the IACE, ICF(iter=4) and ICF-IACE(G=4, iter=4) algorithms, respectively. Meanwhile, when the bit error rate(BER) is 10-3, the optical signal to noise ratio(OSNR) of the proposed scheme is optimized by 2.04 d B, 1.75 d B and 1.4 d B compared with that of clipping, ICF(iter=4) and ICF-IACE(G=4, iter=4) algorithms, respectively. On the other hand, the proposed scheme can reduce the number of complex multiplications by 14.29% and complex additions by 28.57% compared with the ICF(iter=14) scheme.