scholarly journals A Channel Model to Deal with Distributed Noises and Nonlinear Effects in a Fiber System with Distributed Raman Amplifiers

2019 ◽  
Vol 10 (1) ◽  
pp. 133
Author(s):  
Yao Xie ◽  
Qiguang Feng ◽  
Wei Li ◽  
Qiang Zheng ◽  
You Wang
Keyword(s):  
Channel Model ◽  
Nonlinear Effects ◽  
Critical Issue ◽  
Error Vector Magnitude ◽  
Fiber System ◽  
Fiber Raman Amplifier ◽  
Raman Amplifiers ◽  
Gain Dispersion ◽  
Lower Noise ◽  
Vector Magnitude

Nowadays, the distributed fiber Raman amplifier (FRA) has become more and more popular in long-haul fiber systems, owing to its lower noise figures and weaker nonlinear effects in the link. The critical issue in distributed FRAs is the presence of various kinds of noises and their interactions with the signal. However, the existing Raman channel models and their numerical solving methods can only partially describe how the randomly distributed noises interact with the signal. This causes the difficulties in analyzing the distributed FRA precisely and the inconveniences for the applications and the maintenance of FRA systems. In this paper, we propose a modified Raman channel model to describe more comprehensively the interactions between the distributed noises and the signal under the influence of loss, distributed gain, dispersion, and nonlinear effects in the distributed FRA systems. With the comparisons of the error–vector magnitude (EVM) curves, our model can get lower errors in the experimental results regarding bidirectional pumped FRA single-span fiber systems and multi-span systems with backward-pumped FRAs.

scholarly journals Parallel PWMs Based Fully Digital Transmitter with Wide Carrier Frequency Range

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Bo Zhou ◽  
Kun Zhang ◽  
Wenbiao Zhou ◽  
Yanjun Zhang ◽  
Dake Liu
Keyword(s):  
Carrier Frequency ◽  
Pulse Width ◽  
Power Efficiency ◽  
Intermediate Frequency ◽  
Delay Lines ◽  
Error Vector Magnitude ◽  
Frequency Range ◽  
Digital Transmitter ◽  
High Power Efficiency ◽  
Vector Magnitude

The carrier-frequency (CF) and intermediate-frequency (IF) pulse-width modulators (PWMs) based on delay lines are proposed, where baseband signals are conveyed by both positions and pulse widths or densities of the carrier clock. By combining IF-PWM and precorrected CF-PWM, a fully digital transmitter with unit-delay autocalibration is implemented in 180 nm CMOS for high reconfiguration. The proposed architecture achieves wide CF range of 2 M–1 GHz, high power efficiency of 70%, and low error vector magnitude (EVM) of 3%, with spectrum purity of 20 dB optimized in comparison to the existing designs.

scholarly journals Error Vector Magnitude Analysis in Generalized Fading With Co-Channel Interference

2018 ◽  
Vol 66 (1) ◽  
pp. 345-354 ◽  
Author(s):  
Sudharsan Parthasarathy ◽  
Suman Kumar ◽  
Radha Krishna Ganti ◽  
Sheetal Kalyani ◽  
K. Giridhar
Keyword(s):  
Error Vector Magnitude ◽  
Error Vector ◽  
Channel Interference ◽  
Vector Magnitude

The Measurement on Transmission Characteristic of Fiber Raman Amplifier

2013 ◽  
Vol 303-306 ◽  
pp. 765-768
Author(s):  
Chun Yuan Feng
Keyword(s):  
Raman Effect ◽  
Pump Energy ◽  
Optical Power ◽  
Saturation Phenomenon ◽  
Long Wavelength ◽  
Fiber Raman Amplifier ◽  
Input Signal Power ◽  
Energy Transfers ◽  
Raman Amplifiers ◽  
Power Change

The interaction between the pump and pump, the signal and signal ,the pump and signal in Fiber Raman amplifiers are measured. Three-wavelength pumping at 1427nm, 1445nm and 1466nm, it show that the pump energy transfers from short wavelength to long wavelength, that is, Raman effect exists between the different pumping lights. When the different wavelength signals input at the same time, the output optical power change, which is also caused due to the Raman interactions between different signals. When three-wavelength pumping, the input signal power, respectively 0.03dBm 5.04dBm 15.08dBm, the signal gain values are measured. A significant gain saturation phenomenon in 15.08 dBm appears, and it will intensify as the power increases.

scholarly journals Continuously Frequency-Tunable Horn Filtennas Based on Dual-Post Resonators

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Andreia A. C. Alves ◽  
Luis G. da Silva ◽  
Evandro C. Vilas Boas ◽  
Danilo H. Spadoti ◽  
S. Arismar Cerqueira
Keyword(s):  
Millimeter Waves ◽  
Indoor Environment ◽  
Horn Antenna ◽  
Tunable Filter ◽  
Mean Square ◽  
Error Vector Magnitude ◽  
Tuning Ratio ◽  
Frequency Tunable ◽  
24 Ghz ◽  
Vector Magnitude

This work reports the concept and development of two mechanically frequency-tunable horn filtennas for microwave and millimeter-waves. Our design approach relies on the integration of a horn antenna with a mechanically tunable filter based on dual-post resonators. The proposed filtennas have been manufactured and experimentally characterized, by means of reflection coefficient, radiation pattern, and gain. Measurements demonstrate that both filtennas have a tuning ratio of approximately 1.37 with continuous adjustment. The first prototype operates from 2.56 to 3.50 GHz, whereas in the second one the bandwidth is from 17.4 to 24.0 GHz. In addition, the higher-frequency filtenna has been implemented in a 5.0-meter-reach indoor environment, using a 16-QAM signal at 24 GHz. The best configuration in terms of performance resulted in a root mean square error vector magnitude (EVMRMS) and antenna radiation efficiency of 3.69% and 97.0%, respectively.

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