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Dong Y.,PLA Air Force Aviation University | Zhao S.,PLA Air Force Aviation University | Hou R.,Institute of China Electronic Equipment System Engineering Company | Deng B.,PLA Air Force Aviation University
Optical and Quantum Electronics | Year: 2015

Aiming at the characteristics of dynamic routing and limitation on power in satellite optical network, a wavelength-shift-free regenerative scheme based on two-stage offset filter is put forward. Making use of the property that the signs of chirp induced by self-phase modulation are opposite in semiconductor optical amplifier (SOA) and high nonlinear fiber (HNLF), the scheme imposes a red-shifted filter and a blue-shifted filter respectively on the signals after SOA and HNLF, which not only realizes a two-stage regeneration for signals, but also compensates the frequency offset and keeps the wavelength unchanging before and after the regenerator. The results show that the Q factor of signals can be improved 6 dB, and the timing jitter caused by one-stage offset filter can be suppressed effectively. © 2015 Springer Science+Business Media New York Source


Liu H.,Tsinghua University | Hua N.,Tsinghua University | Wang L.,Tsinghua University | Zheng X.,Tsinghua University | Liu Z.,Institute of China Electronic Equipment System Engineering Company
Photonic Network Communications | Year: 2013

Bandwidth-variable (BV) optical networks have been proposed as a novel technology to provide spectrum-efficient transportation. In order to study the performance of the BV optical networks, we propose a BV extension to RSVP-TE signaling protocol and implement it with different routing schemes on our large-scale ASON test-bed. Results show that the adaptive routing (AR) combined with forward reservation RSVP-TE signaling (AR+RSVP-fBV) scheme has lower routing blocking probability; however, since its signaling blocking probability is higher than the fixed routing (FR) combined with backward reservation RSVP-TE signaling (FR+RSVP-bBV) scheme, it has no significant advantage in the overall blocking performance, especially in a highly dynamic network scenario. The introduction of spectrum conversion cannot improve the overall blocking performance significantly due to its higher signaling blocking probability, and worse yet, it increases setup delay. © 2013 Springer Science+Business Media New York. Source


Dong Y.,PLA Air Force Aviation University | Zhao S.,PLA Air Force Aviation University | Hou R.,Institute of China Electronic Equipment System Engineering Company | Deng B.,PLA Air Force Aviation University
Optical and Quantum Electronics | Year: 2015

Aiming at the characteristics of dynamic routing and limitation on power in satellite optical network, a wavelength-shift-free regenerative scheme based on two-stage offset filter is put forward. Making use of the property that the signs of chirp induced by self-phase modulation are opposite in semiconductor optical amplifier (SOA) and high nonlinear fiber (HNLF), the scheme imposes a red-shifted filter and a blue-shifted filter respectively on the signals after SOA and HNLF, which not only realizes a two-stage regeneration for signals, but also compensates the frequency offset and keeps the wavelength unchanging before and after the regenerator. The results show that the Q factor of signals can be improved 6 dB, and the timing jitter caused by one-stage offset filter can be suppressed effectively. © 2015, Springer Science+Business Media New York. Source


Zhou B.,Beijing Institute of Technology | Wang J.,Institute of China Electronic Equipment System Engineering Company
Journal of Semiconductor Technology and Science | Year: 2015

A CMOS relaxation oscillator, with high robustness over process, voltage and temperature (PVT) variations, is designed in 0.18 μm CMOS. The proposed oscillator, consisting of full-differential charge-discharge timing circuit and switched-capacitor based voltage-to-current conversion, could be expanded to a simple open-loop frequency synthesizer (FS) with output frequency digitally tuned. Experimental results show that the proposed oscillator conducts subcarrier generation for frequency-modulated ultra-wideband (FM-UWB) transmitters with triangular amplitude distortion less than 1%, and achieves frequency deviation less than 8% under PVT and phase noise of –112 dBc/Hz at 1 MHz offset frequency. Under oscillation frequency of 10.5 MHz, the presented design has the relative FS error less than 2% for subcarrier generation and the power dissipation of 0.6 mW from a 1.8 V supply. © 2015, Institute of Electronics Engineers of Korea. All rights reserved. Source


An J.-K.,Xidian University | Tian B.,Xidian University | Yi K.-C.,Xidian University | Yu Q.,Institute of China Electronic Equipment System Engineering Company
Huanan Ligong Daxue Xuebao/Journal of South China University of Technology (Natural Science) | Year: 2011

Proposed in this paper is a blind identification algorithm of orthogonal frequency division multiplexing (OFDM) signals based on multifractal features, which is applied to the modulation identification in non-cooperative communication. In this algorithm, first, two items, namely the singularity exponent of the maximum multifractal value from communication signals and the span of multifractal from the amplitude of twice Fourier transform of squared analytic communication signals, are extracted as signal feature parameters. Then, a multi-layer decision tree separator is constructed to identify OFDM signals and single-carrier signals. The feature parameters extracted by this algorithm are robust to the number of subcarriers, the length of the cyclic prefix of OFDM signals, the raised-cosine shaping roll-off factor of single-carrier signals and the signal-to-noise ratio (SNR), and the signals are processed in intermediate frequency channel. Thus, the synchronization in time and frequency domains is not required. Simulated results show that the proposed algorithm can identify OFDM signals with a high average identification rate in a wide SNR range. Source

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