摘要
A direct detection optical orthogonal frequency division multiplexing(DDO-OFDM)system using turbo codes is built,and the transmission performance comparison between coded system and uncoded system is analyzed.Three decoding algorithms,which are Log-maximum a posteriori(MAP),Max-Log-MAP and threshold Max-Log-MAP,are used in the turbo coded system.By comparing three decoding algorithms,the system using Max-Log-MAP algorithm has the best bit error rate(BER)performance.At the transmission distance of 240 km,the uncoded system with transmission rate of 30 Gbit/s can get the BER performance at the degree of 8.93×10-3 with optical signal to noise ratio(OSNR)of24 d B,while the turbo coded system with transmission rate of 50 Gbit/s can achieve it within OSNR of 20 d B.
A direct detection optical orthogonal frequency division multiplexing （DDO-OFDM） system using turbo codes is built, and the transmission performance comparison between coded system and uncoded system is analyzed. Three decoding algorithms, which are Log-maximum a posteriori （MAP）, Max-Log-MAP and threshold Max-Log-MAP, are used in the turbo coded system. By comparing three decoding algorithms, the system using Max-Log-MAP algorithm has the best bit error rate （BER） performance. At the transmission distance of 240 km, the uncoded system with transmission rate of 30 Gbit/s can get the BER performance at the degree of 8.93 × 10^-3 with optical signal to noise ratio （OSNR） of 24 dB, while the turbo coded system with transmission rate of 50 Gbit/s can achieve it within OSNR of 20 dB.
基金
supported by the National Natural Science Foundation of China(No.61107052)
the Tianjin Natural Science Foundation of China(No.11JCYBJC0010)
the Tianjin Youth Foundation of China(No.13JCQNJC01800)
