最新刊期
      卷 ， 期 3 ， 1992
      • Liu Yunyao Liu Gu
        Issue 3, Pages: 1-13(1992) DOI: 10.13756/j.gtxyj.1992.03.001
        摘要：Applying the theory of the modelling method, this paper gives the redesign of the frame structure of tributary mapping interface and calculates the jitter with byte stuffing and bit stuffing respectively. The results and compared and discussed.  
        关键词：digital communication;synchronous transport module;frame structure for tributary mapping   
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      • Wang Jiayi et al
        Issue 3, Pages: 14-22(1992) DOI: 10.13756/j.gtxyj.1992.03.002
        摘要：An optical fiber transmission system compatible with present 300 MHz CATV cable transmission system is introduced in this paper. The achievable non-repeater spacing is about 30 km, and the CNR obtained is 43dB.The particular performance requirements on China-made LD—PIN devices for transmitting analogue signal are proposed.  
        关键词：CATV signal transmission;optical fiber transmission system;LD—PIN   
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      • Cao Wei
        Issue 3, Pages: 23-34(1992) DOI: 10.13756/j.gtxyj.1992.03.003
        摘要：Based on the general principle of CELP, this paper proposes an algorism for searching an extended overlapping codebook using autocorrelation method, the new algorism reduces significantly the complexity and volume of storage. The simulation test shows that the speech quality obtained can be compared with that of searching a Gaussian stochastic codebook using full searchig method.  
        关键词：digital communication;codebook;search;voice encoding   
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      • Liu Wen et al
        Issue 3, Pages: 35-41(1992) DOI: 10.13756/j.gtxyj.1992.03.004
        摘要：The main difficulty in fabrication of high frequency and narrow band SAWF is the large centre frequency offset. By using CAD design method and taking some other measures, this difficulty was overcome effectively. Our results of the SAWF ares insertion loss about 8 dB, centre frequency error less than 60 kHz and Q value more than 590.  
        关键词：surface acustic filter;transducer;frequency offset control   
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      • Xie Jingshan
        Issue 3, Pages: 42-48(1992) DOI: 10.13756/j.gtxyj.1992.03.005
        摘要：This paper discusses in depth the modulation response of high speed semiconductor lasers, both small signal and large signal modulation characteristics are described based on the physical mechanism. Focus is placed on the small siganl AM and FM modulation and large signal frequency chirp.  
        关键词：半导体激光器;响应特性;强度调制;频率调制   
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      • Zhong Weiping
        Issue 3, Pages: 49-60(1992) DOI: 10.13756/j.gtxyj.1992.03.006
        摘要：Based on the modified nonlinear schro-dinger equation, we discovered the influence of higher order terms on propagation of optical soliton in a fiber,such as the linear higher order dispersion effect, the nonlinear higher order dispersion effect, the self-induced Raman effect. The resultant influence of all higher order terms described in this paper is given, and the application perspection of optical soliton communicaion is introduced.  
        关键词：optical soliton;optical soliton communication;the self-induced raman effect   
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      • Issue 3, Pages: 61(1992) DOI: 10.13756/j.gtxyj.1992.03.007
        摘要：本专栏刊出的是武汉邮电科学研究院89级5名硕士生论文摘要。本编辑部正进一步组织论文作者,就其论文内容,分专题整理出一批较精练的文章。这些文章本刊计划在今后几期内发表,供读者参考。  
          
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      • Issue 3, Pages: 62(1992) DOI: 10.13756/j.gtxyj.1992.03.008
        摘要：<正> 本文主要从三个方面讨论了34.368Mbit/s和139.264Mbif/s信号进入STM—1的复接设计问题1.V C的形成准同步（?）列各级信号进入STM—1,则首先必须装入相应的V C中,如34.368Mbit/s信号装入V C—（?）中,139.264Mbit/s信号装入V C—4中。本文从减小入抖动的角度出发,采用了一种新的正/零/负码速调整疗法——两过程塞  
          
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      • Issue 3, Pages: 62-63(1992) DOI: 10.13756/j.gtxyj.1992.03.009
        摘要：<正> 伪随机序列在通信中获得广泛应用,如在误码仪中普遍采用m序列作为测试信号,其同步捕捉方法已成为专门的研究课题。本文分析了几种不同的捕捉方案,指出了现有误码仪的不足,即同步丢失门限人为设定(如10-2),当突发误码产生时会导致测试中断,不能显示真实误码率;设计了一种新型同步监测电路,可以检测出真正失步,并对突发误码进行记录。  
          
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      • Issue 3, Pages: 63-64(1992) DOI: 10.13756/j.gtxyj.1992.03.010
        摘要：<正> 本文对LD工作在两种不同偏置条件下.作探测器使用的性能进行了理论分析和实验。对LD探测器潜在用途进行了概述,并作为一个应用的例子,利用LD发/收功能做了光纤故障定位实验。  
          
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      • Issue 3, Pages: 64-65(1992) DOI: 10.13756/j.gtxyj.1992.03.011
        摘要：<正> 在相干光通信系统中,接收端的输入信号与本振信号的偏振状态（SOP）必须匹配,以保证其接收灵敏度。但是,通常使用的单模光纤,由于受温度或其它环境条件的影响,光纤中传输光的偏振态是不稳的,因此,有必要对传输的光信号进行偏振控制。本文所用的控制SOP的器件是挤压控制器,是一种线性双折射元件。  
          
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        发布时间：2023-08-14
      • Issue 3, Pages: 65(1992) DOI: 10.13756/j.gtxyj.1992.03.012
        摘要：<正> 南宁～玉林光缆通信工程是广西壮族自治区第一条长途光缆系统,也是目前我国最长的省内二级干线工程,全长260km,杆路架空敷设。其工作波长为1.3μm,采用六芯单模光缆;传输速率初期按34Mbit/s配置,终期可开通140Mbit/s系统,线路码型481H。此次开通主干电路近120路,60路区间通信电路全开满。全线共设南宁、玉林两终端站;贵港一个分路站;宾阳、黎塘、石南、六塘四个中继站;分南宁～贵港,贵港～玉林两个数字段。其公务和监控方式既可段内又能跨段进行。监控中心设在南宁,通过微机屏幕显示,对所有站别的光电设备实施集中控制管理。  
          
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