This paper describes a new interleaver construction technique for turbo code.The technique searches as much as possible pseudo-random interleaving patterns under a certain condition using genetic algorithms(GAs).The n...This paper describes a new interleaver construction technique for turbo code.The technique searches as much as possible pseudo-random interleaving patterns under a certain condition using genetic algorithms(GAs).The new interleavers have the superiority of the S-random interleavers and this interleaver construction technique can reduce the time taken to generate pseudo-random interleaving patterns under a certain condition.The results obtained indicate that the new interleavers yield an equal to or better performance than the S-random interleavers.Compared to the S-random interleaver,this design requires a lower level of computational complexity.展开更多
A novel Code-Matched interleaver is proposed which decreases the number of the low weight codewords to improve the performance of the Turbo code. The modified design can adapt more kinds of Turbo codes determined by t...A novel Code-Matched interleaver is proposed which decreases the number of the low weight codewords to improve the performance of the Turbo code. The modified design can adapt more kinds of Turbo codes determined by the generator matrix, while it doesn＇t decrease the bit error rate performance of Turbo codes at moderate to high signal to noise ratio. At the same time, in Rayleigh fading channel, the new Code-Matched interleaver can also debase the error floor.展开更多
A new method to design interleaver based on Henon chaos model is presented. The designed interleaver is with rather random behavior. Experimental results show that the proposed S-henon interleaver make a magnitude of ...A new method to design interleaver based on Henon chaos model is presented. The designed interleaver is with rather random behavior. Experimental results show that the proposed S-henon interleaver make a magnitude of im provement in bit error rate （BER） performance by 0.4 dB compared with the S-random interleaver for AWGN channel respectively. The S-henon interleaver may be adapted to 3G mobile communication systems.展开更多
It is well known that interleavers play a critical role in Turbo coding/decoding schemes, and contention-free interleaver design has become a serious problem in the paraUelization of Turbo decoding, which is indispens...It is well known that interleavers play a critical role in Turbo coding/decoding schemes, and contention-free interleaver design has become a serious problem in the paraUelization of Turbo decoding, which is indispensable to meet the demands for high throughput and low latency in next generation mobile communication systems. This paper unveils the fact that interleavers based on permutation polynomials modulo N are contention-free for every window size W, a factor of the intedeaver length N, which, also called maximum contention-free interleavers.展开更多
A novel flat-top and low-dispersion optical interleaver using ring cavities （RCs） in a Mach-Zehnder interferometer （MZI） is proposed. It is composed of eight mirrors and two nested prism pairs. Each prism and the ...A novel flat-top and low-dispersion optical interleaver using ring cavities （RCs） in a Mach-Zehnder interferometer （MZI） is proposed. It is composed of eight mirrors and two nested prism pairs. Each prism and the two mirrors behave as a RC. Phase shift of RC is a periodic function of the frequency of the input light which acts as a phase dispersive mirror. The two phase shifts needed to achieve a flat-top spectral passband are provided by Fresnel reflectivities at the prism-air interface of the two RCs. The optimum interface reflectivities for flat passband, high isolation and low dispersion can be obtained only by choosing an appropriate material for the prism in each RC. The proposed interleaver in a 25 GHz channel spacing application exhibits a 0.5 dB passband greater than 24 GHz （96% of the spacing）, a 30 dB stopband greater than 21.2 GHz （84.8% of the spacing）, a channel isolation higher than 32 dB and chromatic dispersion ±50 ps/nm within the range of center-frequency ：t：2 GHz ITU passband.展开更多
To suppress the dispersion effect, an improved scheme was proposed for Mach-Zehnder intefferometer （MZI） based interleaver. The device consists of an MZI, a fiber loop （FL）, and a phase shifter inserted in FL. The...To suppress the dispersion effect, an improved scheme was proposed for Mach-Zehnder intefferometer （MZI） based interleaver. The device consists of an MZI, a fiber loop （FL）, and a phase shifter inserted in FL. The introduction of π phase shifter into FI, dramatically suppresses the dispersion effiect. Then the transmission response remains square-like shape, with low frequency deviation and high extinction ratio. Moreover, the lower frequency deviation is achieved by reducing the dispersion coefficient. For 100GHz-spacing interleaver, the 0.08nm deviation is reduced to 0.02nm by replacing G.652 with G.655.展开更多
基金Supported by the National Natural Science Foundation of China(60372057) the Key Open laboratory on Information Science and Engineering of Railway Transportation Ministry of Beijing Jiaotong University of China(KLISAE-0103)
文摘This paper describes a new interleaver construction technique for turbo code.The technique searches as much as possible pseudo-random interleaving patterns under a certain condition using genetic algorithms(GAs).The new interleavers have the superiority of the S-random interleavers and this interleaver construction technique can reduce the time taken to generate pseudo-random interleaving patterns under a certain condition.The results obtained indicate that the new interleavers yield an equal to or better performance than the S-random interleavers.Compared to the S-random interleaver,this design requires a lower level of computational complexity.
文摘A novel Code-Matched interleaver is proposed which decreases the number of the low weight codewords to improve the performance of the Turbo code. The modified design can adapt more kinds of Turbo codes determined by the generator matrix, while it doesn＇t decrease the bit error rate performance of Turbo codes at moderate to high signal to noise ratio. At the same time, in Rayleigh fading channel, the new Code-Matched interleaver can also debase the error floor.
基金Supported by the National High Technology Re-search and Development Program of China(2001AA123053)
文摘A new method to design interleaver based on Henon chaos model is presented. The designed interleaver is with rather random behavior. Experimental results show that the proposed S-henon interleaver make a magnitude of im provement in bit error rate （BER） performance by 0.4 dB compared with the S-random interleaver for AWGN channel respectively. The S-henon interleaver may be adapted to 3G mobile communication systems.
基金Project (No. 60332030) supported by the National Natural ScienceFoundation of China
文摘It is well known that interleavers play a critical role in Turbo coding/decoding schemes, and contention-free interleaver design has become a serious problem in the paraUelization of Turbo decoding, which is indispensable to meet the demands for high throughput and low latency in next generation mobile communication systems. This paper unveils the fact that interleavers based on permutation polynomials modulo N are contention-free for every window size W, a factor of the intedeaver length N, which, also called maximum contention-free interleavers.
基金Projet supported by the National Natural Science Foundation of China (Grant No.10804070)the Innovation Program of Education Commission of Shanghai Municipality (Grant No.09YZ06)the Shanghai Leading Academic Discipline Project (Grant No.S30108)
文摘A novel flat-top and low-dispersion optical interleaver using ring cavities （RCs） in a Mach-Zehnder interferometer （MZI） is proposed. It is composed of eight mirrors and two nested prism pairs. Each prism and the two mirrors behave as a RC. Phase shift of RC is a periodic function of the frequency of the input light which acts as a phase dispersive mirror. The two phase shifts needed to achieve a flat-top spectral passband are provided by Fresnel reflectivities at the prism-air interface of the two RCs. The optimum interface reflectivities for flat passband, high isolation and low dispersion can be obtained only by choosing an appropriate material for the prism in each RC. The proposed interleaver in a 25 GHz channel spacing application exhibits a 0.5 dB passband greater than 24 GHz （96% of the spacing）, a 30 dB stopband greater than 21.2 GHz （84.8% of the spacing）, a channel isolation higher than 32 dB and chromatic dispersion ±50 ps/nm within the range of center-frequency ：t：2 GHz ITU passband.
基金Supported by the National Natural Science Foundation of China （No.10174057, 90201011） and the Key Project of Chinese Ministry of Education （No.105148）.
文摘To suppress the dispersion effect, an improved scheme was proposed for Mach-Zehnder intefferometer （MZI） based interleaver. The device consists of an MZI, a fiber loop （FL）, and a phase shifter inserted in FL. The introduction of π phase shifter into FI, dramatically suppresses the dispersion effiect. Then the transmission response remains square-like shape, with low frequency deviation and high extinction ratio. Moreover, the lower frequency deviation is achieved by reducing the dispersion coefficient. For 100GHz-spacing interleaver, the 0.08nm deviation is reduced to 0.02nm by replacing G.652 with G.655.
