The effect of intra-channel four-wave mixing on the performance of a 160 Gb/s OTDM RZ 100 km transmission system is analyzed. Strong dispersion management to suppress the detrimental effects of intra-channel four-wave...The effect of intra-channel four-wave mixing on the performance of a 160 Gb/s OTDM RZ 100 km transmission system is analyzed. Strong dispersion management to suppress the detrimental effects of intra-channel four-wave mixing is presented theoretically and verified experimentally. Results demonstrate that amplitude fluctuation and ghost pulses are well suppressed by strong dispersion management. Stable (>2 h) error-free (10-12 ) transmission over 100 km is achieved without forward-error correction, and the power penalty is ～3.6 dB.展开更多
We propose a novel audio watermarking scheme which can recover the original audio carrier perfectly if the watermarked audio is modified. Besides, we can adjust the maximum tampered rate allowed and the quality of wat...We propose a novel audio watermarking scheme which can recover the original audio carrier perfectly if the watermarked audio is modified. Besides, we can adjust the maximum tampered rate allowed and the quality of watermarked audio flexibly as required. In the scheme, an efficient generalized integer transform is improved to embed watermark data which are composed of least significant bits（LSBs） of averages in each patch, reference-bits and check-bits. LSBs are needed in the inverse transform. Then, by comparing the extracted check-bits and calculated ones, the modified area can be localized. Finally, reliable reference-bits and samples data help us reconstruct the original audio without errors. The efficiency of the proposed method is theoretically and experimentally verified.展开更多
The existence of error when compressing nonlinear functions into the coefficients of the characteristic model is known to be a key issue in existing characteristic modeling approaches,which is solved in this work by a...The existence of error when compressing nonlinear functions into the coefficients of the characteristic model is known to be a key issue in existing characteristic modeling approaches,which is solved in this work by an error-free compression method.We first define a key concept of relevant states with corresponding compressing methods into their coefficients,where the coefficients are continuous and bounded and the compression is error-free.Then,we give the conditions for decoupling characteristic modeling for MIMO systems,and sequentially,we establish characteristic models for nonlinear systems with minimum phase and relative order two as well as the flexible spacecrafts,realizing the equivalence in the characteristic model theory.Finally,we explicitly explain the reasons for normalization in the characteristic model theory.展开更多
A single channel with a 160-Gb/s optical time-division-multiplexing （OTDM） transmission over 100 km is fabricated. With the help of 500-GHz optical sampling oscilloscopes, the fiber length is adjusted to the order o...A single channel with a 160-Gb/s optical time-division-multiplexing （OTDM） transmission over 100 km is fabricated. With the help of 500-GHz optical sampling oscilloscopes, the fiber length is adjusted to the order of 10 m, which corresponds to the accuracy of 0.4 ps for the dispersion compensation. The dispersion map is optimized for the 100-km transmission link. A completely error-free transmission with the power penalty of 3.6 dB is achieved for 2 h without using forward error correction.展开更多
The production mechanism of non-return-to-zero(NRZ),return-to-zero(RZ)and carrier suppressed return-to-zero(CSRZ)was analyzed theoretically in this paper.We compared the transmission performance of CSRZ with RZ and NR...The production mechanism of non-return-to-zero(NRZ),return-to-zero(RZ)and carrier suppressed return-to-zero(CSRZ)was analyzed theoretically in this paper.We compared the transmission performance of CSRZ with RZ and NRZ formats at 10 Gb/s system by numerical simulation.And we simulated the transmission model constructed with Erbium-doped fiber amplifier(EDFA)as the solo amplifier and the chirped fiber Bragg grating(CFBG)as the solo dispersion compensator used in the system.A practical 8x10 Gb/s 2560 km transmitted experiment was conducted in straight line with these different modulation formats mentioned above and the experiment results show very good agreement with the result of computer simulation.The CSRZ format is more effective than other formats in the system,and involved only 2.5 dB power penalty cost in the practical 2560 km error-free experiment.The results also show that CSRZ will help to optimize the transmitted results and reduce the transmitted penalty further.展开更多
基金supported by the Fundamental Research Funds for the Central Universities (2009YJS005)National High Technology Research and Development Projects of China (2007AA01Z258,2008AA01Z15)+3 种基金the National Natural Science Foundation of China (60807003)the Beijing Nova Program (2008A026)the Natural Science Foundation of Beijing (4062027)the National Natural Science Foundation of China (60877042,60837003)
文摘The effect of intra-channel four-wave mixing on the performance of a 160 Gb/s OTDM RZ 100 km transmission system is analyzed. Strong dispersion management to suppress the detrimental effects of intra-channel four-wave mixing is presented theoretically and verified experimentally. Results demonstrate that amplitude fluctuation and ghost pulses are well suppressed by strong dispersion management. Stable (>2 h) error-free (10-12 ) transmission over 100 km is achieved without forward-error correction, and the power penalty is ～3.6 dB.
基金Supported by the National Natural Science Foundation of China(61272414)the Science and Technology Project of Guangzhou of China(2012J4100108)the Jinan University’s Scientific Research Creativeness Cultivation Project for Outstanding Undergraduates Recommended for Postgraduate Study
文摘We propose a novel audio watermarking scheme which can recover the original audio carrier perfectly if the watermarked audio is modified. Besides, we can adjust the maximum tampered rate allowed and the quality of watermarked audio flexibly as required. In the scheme, an efficient generalized integer transform is improved to embed watermark data which are composed of least significant bits（LSBs） of averages in each patch, reference-bits and check-bits. LSBs are needed in the inverse transform. Then, by comparing the extracted check-bits and calculated ones, the modified area can be localized. Finally, reliable reference-bits and samples data help us reconstruct the original audio without errors. The efficiency of the proposed method is theoretically and experimentally verified.
基金This work was supported by the National Key R&D Program of China(Grant Nos.2018YFA0703800 and 2018AAA0100800)the Science and Technology on Space Intelligent Control Laboratory Foundation of China(Grant No.ZDSYS-2018-04)the National Natural Science Foundation of China(Grant Nos.U20B2054 and 51805025).
文摘The existence of error when compressing nonlinear functions into the coefficients of the characteristic model is known to be a key issue in existing characteristic modeling approaches,which is solved in this work by an error-free compression method.We first define a key concept of relevant states with corresponding compressing methods into their coefficients,where the coefficients are continuous and bounded and the compression is error-free.Then,we give the conditions for decoupling characteristic modeling for MIMO systems,and sequentially,we establish characteristic models for nonlinear systems with minimum phase and relative order two as well as the flexible spacecrafts,realizing the equivalence in the characteristic model theory.Finally,we explicitly explain the reasons for normalization in the characteristic model theory.
基金supported by the Natural Science Foundation of Beijing(No.4062027)the National"863"Project of China(Nos.2007AA01Z258 and 2008AA01Z15)the National Natural Science Foundation of China(Nos.60877042 and 60837003)
文摘A single channel with a 160-Gb/s optical time-division-multiplexing （OTDM） transmission over 100 km is fabricated. With the help of 500-GHz optical sampling oscilloscopes, the fiber length is adjusted to the order of 10 m, which corresponds to the accuracy of 0.4 ps for the dispersion compensation. The dispersion map is optimized for the 100-km transmission link. A completely error-free transmission with the power penalty of 3.6 dB is achieved for 2 h without using forward error correction.
基金supported by Hi-Tech Research and Development Program of China(No.2001AA122012)the National Natural Science Foundation of China(Grant No.60337010).
文摘The production mechanism of non-return-to-zero(NRZ),return-to-zero(RZ)and carrier suppressed return-to-zero(CSRZ)was analyzed theoretically in this paper.We compared the transmission performance of CSRZ with RZ and NRZ formats at 10 Gb/s system by numerical simulation.And we simulated the transmission model constructed with Erbium-doped fiber amplifier(EDFA)as the solo amplifier and the chirped fiber Bragg grating(CFBG)as the solo dispersion compensator used in the system.A practical 8x10 Gb/s 2560 km transmitted experiment was conducted in straight line with these different modulation formats mentioned above and the experiment results show very good agreement with the result of computer simulation.The CSRZ format is more effective than other formats in the system,and involved only 2.5 dB power penalty cost in the practical 2560 km error-free experiment.The results also show that CSRZ will help to optimize the transmitted results and reduce the transmitted penalty further.
