Degradation of Bi-Directional Single Fiber Transmission in WDM-PON Due to Beat Noise

This paper presents a general formulation for the impact of back-reflection in wavelength division multiplexing-passive optical networks (WDM-PON) access networks. The analysis is applied to various wavelength-independent optical network unit (ONU) configurations such as amplified spontaneous emission (ASE)-locked Fabry-Perot (FP) lasers, reflective semiconductor optical amplifiers or injection locked FP using the downstream signal. The power penalty due to beat noise and its dependence on relative intensity noise, transmitter linewidth, and receiver bandwidth is investigated. The optimal gain at the ONU that minimizes the effect of beat noise is also found. The results show that the power penalty decreases as the linewidth of the the optical line terminal (OLT) and ONU light source increase.     

UWB信号光纤传输性能分析

该文分析了超宽带(UWB)信号光纤传输的性能,分析对比了电UWBmonocycle和doublet信号经过光强度调制后光纤传输的性能,介绍了两种光生UWBmonocycle脉冲的方法,分析了这两种方法产生的信号经光纤传输后的时域波形与频谱。研究结果对实际的UWBover fiber系统应用具有指导意义。     

Bit-Error-Rate Degradation in a Multimode Fiber Optic Transmission Link Due to Modal Noise

A review is given of the statistics of modal noise and of the expressions for the signal-to-noise ratio for the cases of a monochromatic and a nonmonochromatic light source including the effects of source frequency fluctuations. Using the results, a quantitative analysis is made of how modal noise degrades the bit-error-rate performance of a digital transmission link with multimode fiber. Plots of the bit-error rate versus the received optical power show the characteristic asymptotic behavior (BER floor); expressions are derived for the asymptotic BER. The power penalty due to modal noise can be considerably reduced by suitable system modifications, e.g., by optimization of the decision threshold setting or by application of a low coherent light source such as an LED or a laser diode operating with several spectral emission lines of low coherence and low partition noise.     

Performance Impairments in Single-Mode Radio-Over-Fiber Systems Due to MAC Constraints

This paper investigates performance impairments due to constraints imposed by the MAC layer when single-mode fiber (SMF) is used to extend the reach of an IEEE 802.11 network. It is shown that data throughput decreases as fiber length increases. It is also noted that the network fails long before physical layer limitations set in due to the timeout values defined within the MAC protocol. This study is based on both variants of the IEEE 802.11 Distributed Coordination Function. Moreover, both UDP and TCP packet transmissions are taken into account. An experimental enquiry is initially developed to provide a set of validation points before extending these results by simulations using the OPNET platform. Finally, an analytical approximation is presented to these results that allows designers of Radio-over-fiber (RoF) systems to quickly and accurately predict the data throughput given the specific parameters of their network. To our knowledge, this is the first analysis of this kind for a long reach fiber system.      

光纤CATV信号传输对激光器要求的分析

激光器是多频道光纤ＣＡＴＶ系统中提高传输信号质量的关键器件,特别是在受色散和非线性影响的基于Ｇ．６５２光纤的１５５０ｎｍＶＳＢ－ＡＭ系统中。文章从激光器的本征特性和光纤的传输特性的角度讨论了系统对激光器性能的特殊要求,提出能够满足系统要求的激光器的典型性能指标,并介绍了几种适用于光纤ＣＡＴＶ的新型激光器及其发展。     

电视信号的光纤传输

本文简要介绍了光纤传输系统光发送、光传输、光接收部分的组成和传输特性     

Analog Decoder Performance Degradation Due to BJTs' Parasitic Elements

This paper presents the effect of bipolar junction transistors' (BJTs) parasitic elements on the decoding performance of a BiCMOS analog decoder. The transistors' parasitic effects are taken into account to develop a more accurate behavioral model of the computing nodes. The model is applied to double-binary 0.25-${rm mu}hbox{m}$ BiCMOS analog decoders. Behavioral simulations show that the BJTs' parasitic elements deteriorate the error-correcting performance of a stand-alone a posteriori probability (APP) decoder by 0.5 dB compared with the ideal bit error rate (BER). In a turbo scheme, the loss is reduced to 0.2 dB for a BER that is smaller than $10^{-2}$. A simple solution based on an nMOS amplifier is proposed to counterbalance the dominant parasitic element. The amplifier reduces the degradation by 0.2 dB for the APP decoder. However, the turbo decoder is improved only for a BER above $10^{-2}$.      

Transmission Performance Simulation Study Evaluation for High Speed Radio Over Fiber Communication Systems

Radio over fiber communication system technology modulation techniques are presented in this study in order to enhance the performance behavior of optical fiber communication systems. The proposed modulation techniques used to meet this aim mainly consist from a mixture of traditional modulation technologies. The proposed modulation technologies include merging modulation techniques such as pulse amplitude frequency modulation, quadrature amplitude frequency modulation, differential phase shift keying amplitude modulation, offset quadrature phase shift keying amplitude modulation and frequency phase modulation are applied on different optical communication system models. The different types of modulation techniques are illustrated and discriminated in current research paper that provides measured quantities details that namely received power, maximum Q-factor and minimum bit error rate regarding to simulation results. Optiwave Simulation Version 13 software is the basic tool which is used to study proposed models.

     

28路AM-VSB电视信号光纤传输系统的性能分析

分析了28路AM—VSB电视信号光纤传输系统的性能,着重讨论了激光器非线性引起的互调失真及光接收噪声性能,并给出了激光器互调干扰的简便测试方法及激光调制指数的优化选择方法。     

Experimental Comparison of Transmission Performance of Multichannel OFDM-UWB Signals on FTTH Networks

The experimental demonstration of radio-over-fiber Wimedia-defined OFDM ultrawide band (OFDM-UWB) wireless transmission in fiber-to-the-home (FTTH) networks using standard single-mode fiber with lengths ranging from 25 to 100 km is reported in this paper.      

Digital Transmission Performance on Fading Dispersive Diversity Channels

The reception and detection of a single digit under known channel conditions are investigated. The probability of error for an optimum one-shot receiver instantaneously matched to the channel state is averaged over an ensemble of dispersive diversity channels. The average probability of error as a function of energy to noise ratio is found to be solely dependent on the ratio of rms dispersion width to data symbol width. For these dispersive channels an implicit diversity effect is qualitatively explained in terms of eigenvalues that depend on the ensemble statistic. The one-shot receiver performance provides a bound for practical receivers. In a comparison with a decision feedback equalizer, it is shown that on moderately dispersive channels the equalizer nearly achieves optimum one-shot performance. Since an adaptive version of this equalizer exists, this means data transmission on slowly fading channels is possible at rates above the natural rate suggested by the channel dispersion spread without bandwidth expansion and with small intersymbol interference penalty. The use of one-shot receiver performance curves can also be used as estimates of equalizer performance in situations where computation of the latter is impractical.     

10 Gb/s 120-km Bidirectional Repeaterless Transmission over Single-Mode Fiber

A successful repeaterless 10 Gb/s bidirectional transmission experiment is demonstrated at the 1550 nm wavelength through 120 km of single-mode fiber. Fiber chromatic dispersion compensation in both transmission directions is realized by insertion of the same dispersion compensating fiber in the transmission fiber span. Excellent long-term error rate performance (BER < 10-¹⁴) is achieved by suppression of the Rayleigh backscattered signal power with low loss narrow-band fiber grating reflection filters.     

基于ZEMAX单模大光束光纤准直透镜信号耦合分析

针对光纤连接器核心部件之一光纤准直透镜信号精密耦合问题,采用双合透镜设计了一种单模大光束光纤连接器.通过分析双合透镜特性、光纤准直器阵列中的多光学器件耦合机理和准直透镜间的3种耦合偏差引起的传输损耗,推导出该耦合系统的传输损耗公式.基于MATLAB分析得到:角向失配对准直器的耦合损耗影响最大,轴向失配影响最小.利用光学...     

SNDR Measurement of Radio Over Fiber System Based on High Performance Generation Method Along with Optic Amplifier Link

Wireless Personal Communications - The medical enhancements have been improved to increase the life span of mankind. High penetration of Wireless Sensor Network in medical field helped the doctors...     

半导体激光器到单模光纤的高效耦合技术

本文在阐述了半导体激光器到单模光纤的耦合损耗来源之后，对几种典型的耦合技术作了较为详细的分析和比较，明确了增大数值孔径、减小系统球差和椭圆度校正三个主要因素对进一步提高耦合效率的意义。最后，探讨了耦合技术的发展前景。     

利用有线电视光缆传输广播节目信号

广播电台播控中心与发射台往往是分离的 ,有的相隔几百米 ,远的则几公里。我台播控中心与远离市区的发射台相隔 6 km ,这给广播节目信号传输带来了极大的不便 ,为了安全、优质、不间断地把广播信号传输到发射台 ,多年来想了不少的办法 ,用了几种传输方式 ,均因故障率高、投入大、传输效果差被淘汰。最初用自备电话电缆传输广播信号 ,距离远、信号衰减大 ,特别是高频成分衰耗太大 ,造成语言节目声音发闷 ,含混不清 ;音乐节目无高低之分 ,失去了音乐的美感。为了改变这一状况 ,我们投资购置了一套微波设备。微波机是国产晶体管分离元件构成。…     

广播节目传送中传输音频信号应注意的问题

为保证广播节目的传输质量,必须规范音频信号的传输标准。基于此结合实际工作,阐述了广播音频信号传输中常见的几个问题：平衡和不平衡的连接问题、阻抗匹配问题以及音频的接地问题,有利于提高音频信号的传输质量。通过实际运用经验的摸索和总结使大家对这些容易忽视的问题进行有效解决和防范,并使大家对这几个问题有一个理论联系实际的提高。     

模拟数字信号光纤传输系统的实现

设计了一套以光收发模块为核心的数字信号光纤传输实验系统。系统可同时完成模拟(声音、图像)信号、数字信号的传输,同时可通过复杂可编程逻辑器件对数字信号进行编解码设置。该设备可用于数字信号光纤传输教学和一些小型局域网的数据传送,且具有较强的实用意义。     

Developments in Single-Mode Fiber Design, Materials, and Performance at Bell Laboratories

Some aspects of single-mode fiber research and development at Bell Laboratories are presented. The most recent evolution in single-mode fiber design and fabrication technology has resulted in a fiber in which mode size and zero dispersion wavelength can be independently chosen at a fixed cutoff wavelength.     

Transmission Restriction and Suppression of Radio over Fiber Communication System

This article puts forward long-reach and high-performance Radio over Fiber (RoF) Communication Systems.Two schemes are proposed for solving the transmission restriction factors of the RoF system and verifies the system through experiments.One scheme is 40GHz RoF system based on external modulation with odd-order sideband-suppressed.The other one is 40GHz Optical Frequency Division Multiplexing (OFDM) system based on Optical Carrier-Suppression (OCS),external modulation.Both theory and experiment prove that the two systems allow not only low chromatic dispersion,but also long-distance transmission.