《电信传输原理及应用》习题

《电信传输原理及应用》习题 电信传输习题 第1章 电信传输的基本概念 一、实践活动 1(实地参观当地的中国电信市话传输机房，建立对传输系统整体、直观的印象，询问有关技术人员进一步了解市话对称电缆、同轴电缆、光纤的使用状况。 2(了解身边无线通信网络，特别要留心一下学校周边的各种基站、卫星地面站、微波中继及天线。 3(实地参观学校的专业实验室，向老师咨询传输线路和传输设备种类及用途。 二、思考与练习 1. 什么是通信、电信和电信传输,电信号有哪些种类,各有什么特征, 2. 完整的电信传输系统的是如何组成的, 3. 电信传输有些什么特点, 4. 常用传输介质的结构及用途是什么, 5、以功率电平为例，请简述正电平、负电平和零电平的意义。 6、试简述绝对电平和相对电平的意义以及两者之间的关系。 7(已知测试点的阻抗R=75Ω,其电压为0.85V，试计算测试点上的绝对功率电平是多少, L 8(设电路某点的绝对功率电平为 (1)0.5N， (2)-1.5 N， (3)-7 dBm PP 试求该点的功率值。 9(已知测试点功率为0.2w，线路始端功率为10mw，求测试点的相对功率电平值。 10(已知测试点电压为0.7V，线路始端电压为0.2V，求测试点的相对电压电平值。 第2章 金属传输线理论 一、实践活动 实地参观当地的中国电信市话传输机房，询问有关技术人员进一步了解市话对称电缆、同轴电缆使用状况。 二、思考与练习 1.集总参数与分布参数有哪些异同, 2.何为长线,何为短线, 3.阐述金属传输线出现R、L、C和G的原因及它们的物理意义 4.传输线的特性阻抗和传输常数代 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 什么意义, 5.当Z=Z时，传输线处于什么工作状态,传输线具有什么特点, CL 6.当Z?Z时，传输线处于什么工作状态,传输线具有什么特点, CL 7.通信回路的串音损耗与串音防卫度的物理意义是什么, 8.若已知f=5MHz，同轴电缆回路的一次参数:电阻R,50,/km，电感L,0.2mH/km，11电导G,15,S/km，电容C,33nF/km。试求该同轴电缆的二次参数。 11 9(设某平行双导线的直径为2mm，间距为8mm，周围介质为空气，求其特性阻抗。 10(设某同轴线的外导体内直径为20mm，内导体外直径为10mm，求其特性阻抗;若在内外导体之间填充ε为2.20的介质，求其特性阻抗。 integrated energy, chemicals and textile Yibin city, are the three core pillars of the industry. In 2014, the wuliangye brand value to 73.58 billion yuan, the city's liquor industry slip to stabilise. Promoting deep development of integrated energy, advanced equipment manufacturing industry, changning district, shale gas production capacity reached 277 million cubic metres, built the country's first independent high-yield wells and pipelines in the first section, the lead in factory production and supply to the population. 2.1-3 GDP growth figure 2.1-4 Yibin, Yibin city, Yibin city, fiscal revenue growth 2.1.4 topography terrain overall is Southwest, North-Eastern State. Low mountains and hills in the city landscape as the main ridge-and-Valley, pingba small fragmented nature picture for "water and the second land of the seven hills". 236 meters to 2000 meters above sea level in the city, low mountain, 46.6% hills 45.3%, pingba only 8.1%. 2.1.5 development of Yibin landscapes and distinctive feature in the center of the city, with limitations, and spatial structure of typical zonal group, 2012-cities in building with an area of about 76.2km2. From city-building situation, "old town-the South Bank" Center construction is lagging behind, disintegration of the old city is slow, optimization and upgrading, quality public service resources are still heavily concentrated in the old town together. Southbank Centre has not been formed, functions of the service area space is missing. Meanwhile, peripheral group centres service was weak and inadequate accounting for city development, "suspicious" pattern could not be formed. As regards transport, with the outward expansion of cities, cities have been expanding, centripetal city traffic organization has not changed, integrated energy, chemicals and textile Yibin city, are the three core pillars of the industry. In 2014, the wuliangye brand value to 73.58 billion yuan, the city's liquor industry slip to stabilise. Promoting deep development of integrated energy, advanced equipment manufacturing industry, changning district, shale gas production capacity reached 277 million cubic metres, built the country's first independent high-yield wells and pipelines in the first section, the lead in factory production and supply to the population. 2.1-3 GDP growth figure 2.1-4 Yibin, Yibin city, Yibin city, fiscal revenue growth 2.1.4 topography terrain overall is Southwest, North-Eastern State. Low mountains and hills in the city landscape as the main ridge-and-Valley, pingba small fragmented nature picture for "water and the second land of the seven hills". 236 meters to 2000 meters above sea level in the city, low mountain, 46.6% hills 45.3%, pingba only 8.1%. 2.1.5 development of Yibin landscapes and distinctive feature in the center of the city, with limitations, and spatial structure of typical zonal group, 2012-cities in building with an area of about 76.2km2. From city-building situation, "old town-the South Bank" Center construction is lagging behind, disintegration of the old city is slow, optimization and upgrading, quality public service resources are still heavily concentrated in the old town together. Southbank Centre has not been formed, functions of the service area space is missing. Meanwhile, peripheral group centres service was weak and inadequate accounting for city development, "suspicious" pattern could not be formed. As regards transport, with the outward expansion of cities, cities have been expanding, centripetal city traffic organization has not changed, 第3章 波导传输线理论 一、实践活动 实地参观当地的中国电信微波发射站，直观观测波导、同轴线几何尺寸与传输信号频率的关系，与单模传输的关系。 二、思考与练习 1( 波导为什么不能传输TEM波, 2( 波导波长与工作波长有何区别, 3一空气填充的矩形波导，其截面尺寸a = 8cm, b = 4cm，试画出截止波λc长的分布图，并说明工作频率f1=3GHz和f2=5GHz的电磁波在该波导中可以传输哪些模式。 4(若将3cm标准矩形波导BJ-100型(a = 22.86mm , b,10.16mm)用来传输工作波长 λ0= 5cm的电磁波，试问是否可能,若用BJ-58型(a =40.4mm, b = 20.2mm)用来传输波长λ0= 3cm的电磁波是否可能,会不会产生什么问题, 5(设有标准矩形波导BJ-32型，a=72.12rnm, b,34.04mm (1)当工作波长λ=6cm时，该波导中可能传输哪些模式, (2)设λ0=10cm并工作于TE10模式，求相位常数β、波导波长λp、相速度Vp、群速 度Vg、和波阻抗Z TE10 6(在BJ-100型的矩形波导中传输频率f =10GHz的TE10模式的电磁波。 (1)求λC、β、λp、和Z TE10 (2)若波导宽边a增大一倍，上述各量如何变化, (3)若波导窄边尺寸b增大一倍，上述各量又将如何变化, (4)若波导截面尺寸不变，但工作频率变为15GHz，上述各量又将如何变化, 7(有一空气填充的矩形波导工作于TE10模式，其工作频率为10GHz，已测得波导波长λp ,4cm，试求: (1)截止频率f,和截止波长λC; (2)相速度Vp、群速度Vg和波阻抗Z; TE10 8(有一内充空气，b 要求 对教师党员的评价套管和固井爆破片与爆破装置仓库管理基本要求三甲医院都需要复审吗 工作频率至少高于主模截止频率的20,和至少低于次一高阶模式截止频率的20%，试设计该波导的截面尺寸a和b 。 9(设有空气填充的内直径为5cm的圆形波导，试求: (1) TE11, TMo1和TE01,模式的截止波长; (2)当工作波长分别为7cm, 6cm和3cm时，波导中可能存在哪些模式, (3) λ0为7cm时主模的β、Vp、Vg、λp 和波阻抗。 10(空气填充的圆形波导中传输主模，已知工作频率f = 5GHz, λo /λc= 0.9，试求: (1)该波导的内直径; (2)β和λp 11(设计一圆波导，工作波长λ=7 cm，只容许TE波传输。 11 12(有一空气同轴线的截面尺寸a =10mm, b = 40mm 。 (1)计算TE11, TE01和TM01三种模式的截止波长; (2)当工作波长λ0=10cm时，求TEM模和TE11模的相速度。 13(有一同轴线内导体的半径a=0.5mm，b=1.75mm，若绝缘材料的介电常数为1。该同轴线的特性阻抗为多少,并计算单模工作的工作频率范围。 integrated energy, chemicals and textile Yibin city, are the three core pillars of the industry. In 2014, the wuliangye brand value to 73.58 billion yuan, the city's liquor industry slip to stabilise. Promoting deep development of integrated energy, advanced equipment manufacturing industry, changning district, shale gas production capacity reached 277 million cubic metres, built the country's first independent high-yield wells and pipelines in the first section, the lead in factory production and supply to the population. 2.1-3 GDP growth figure 2.1-4 Yibin, Yibin city, Yibin city, fiscal revenue growth 2.1.4 topography terrain overall is Southwest, North-Eastern State. Low mountains and hills in the city landscape as the main ridge-and-Valley, pingba small fragmented nature picture for "water and the second land of the seven hills". 236 meters to 2000 meters above sea level in the city, low mountain, 46.6% hills 45.3%, pingba only 8.1%. 2.1.5 development of Yibin landscapes and distinctive feature in the center of the city, with limitations, and spatial structure of typical zonal group, 2012-cities in building with an area of about 76.2km2. From city-building situation, "old town-the South Bank" Center construction is lagging behind, disintegration of the old city is slow, optimization and upgrading, quality public service resources are still heavily concentrated in the old town together. Southbank Centre has not been formed, functions of the service area space is missing. Meanwhile, peripheral group centres service was weak and inadequate accounting for city development, "suspicious" pattern could not be formed. As regards transport, with the outward expansion of cities, cities have been expanding, centripetal city traffic organization has not changed, integrated energy, chemicals and textile Yibin city, are the three core pillars of the industry. In 2014, the wuliangye brand value to 73.58 billion yuan, the city's liquor industry slip to stabilise. Promoting deep development of integrated energy, advanced equipment manufacturing industry, changning district, shale gas production capacity reached 277 million cubic metres, built the country's first independent high-yield wells and pipelines in the first section, the lead in factory production and supply to the population. 2.1-3 GDP growth figure 2.1-4 Yibin, Yibin city, Yibin city, fiscal revenue growth 2.1.4 topography terrain overall is Southwest, North-Eastern State. Low mountains and hills in the city landscape as the main ridge-and-Valley, pingba small fragmented nature picture for "water and the second land of the seven hills". 236 meters to 2000 meters above sea level in the city, low mountain, 46.6% hills 45.3%, pingba only 8.1%. 2.1.5 development of Yibin landscapes and distinctive feature in the center of the city, with limitations, and spatial structure of typical zonal group, 2012-cities in building with an area of about 76.2km2. From city-building situation, "old town-the South Bank" Center construction is lagging behind, disintegration of the old city is slow, optimization and upgrading, quality public service resources are still heavily concentrated in the old town together. Southbank Centre has not been formed, functions of the service area space is missing. Meanwhile, peripheral group centres service was weak and inadequate accounting for city development, "suspicious" pattern could not be formed. As regards transport, with the outward expansion of cities, cities have been expanding, centripetal city traffic organization has not changed, 第4章 介质光波导传输理论 一、实践活动 实地参观当地的中国电信市话光纤传输机房，询问有关技术人员进一步了解通信传输 网对光纤应用状况以及光纤传输特性现状。 二、思考与练习 1(什么是光纤的数值孔径, 2(阶跃型光纤场方程的推导思路是什么, 3(用射线理论描述阶跃型光纤的导光原理是什么,画出示意图 4(写出导波的径向归一化相位常数、径向衰减常数、归一化频率的表达式。并简述其物理 意义。 5(判断某种模式能否在光纤中传输的条件是什么, 6(阶跃型光纤的单模传输条件是什么, 7(什么是单模光纤的截止波长,写出表达式。 8(光纤产生的原因及其危害是什么, 9(光纤损耗和色散产生的原因及其危害是什么,为什么说光纤的损耗和色散会限制系统的 光纤传输距离, 10(光纤中都有哪几种色散,解释其含义。 11.已知渐变型光纤纤芯的折射率分布为 r2n(r),n(0)1,2,() 0,r,a a 求: 光纤的本地数值孔径NA(r)。 12(均匀光纤芯与包层的折射率分别为:n,1(50，n,1(45，试计算: l2(1)光纤芯与包层的相对折射率差Δ, (2)光纤的数值孔径NA, (3)在1km长的光纤上，由子午线的光程差所引起的最大时延差Δτ , max(4)若在1km长的光纤上,将Δτ减小为10ns/km, n应选什么值. max213. 已知阶跃光纤纤芯的折射率n,1.465，相对折射率差 Δ= 0.01，纤芯半径a,25μm 试l 求: LP、LP、LP和LP模的截止波长各为多少, OlO21112 14.阶跃光纤，若n,1.50, λ=l.3μm，试计算 l0 (1)若Δ= 0(25，为了保证单模传输，其纤芯半径a应取多大, (2)若取a=5μm ，为保证单模传输，Δ应取多大, 15.阶跃折射率光纤中n,1.52，n,1.49 l2 (1)光纤浸在水中(n,1.33)，求光从水中入射到光纤输入端面的最大接收角; 0 (2)光纤放置在空气中，求数值孔径。 16.一阶跃折射率光纤，纤芯半径a=25μm，折射率n,1.50，相对折射率差Δ=1,， l长度 L=2km。求: (1)光纤的数值孔径; (2)子午光纤的最大时延差; (3)若将光纤的包层和涂数层去掉，求裸光纤的NA和最大时延差。 integrated energy, chemicals and textile Yibin city, are the three core pillars of the industry. In 2014, the wuliangye brand value to 73.58 billion yuan, the city's liquor industry slip to stabilise. Promoting deep development of integrated energy, advanced equipment manufacturing industry, changning district, shale gas production capacity reached 277 million cubic metres, built the country's first independent high-yield wells and pipelines in the first section, the lead in factory production and supply to the population. 2.1-3 GDP growth figure 2.1-4 Yibin, Yibin city, Yibin city, fiscal revenue growth 2.1.4 topography terrain overall is Southwest, North-Eastern State. Low mountains and hills in the city landscape as the main ridge-and-Valley, pingba small fragmented nature picture for "water and the second land of the seven hills". 236 meters to 2000 meters above sea level in the city, low mountain, 46.6% hills 45.3%, pingba only 8.1%. 2.1.5 development of Yibin landscapes and distinctive feature in the center of the city, with limitations, and spatial structure of typical zonal group, 2012-cities in building with an area of about 76.2km2. From city-building situation, "old town-the South Bank" Center construction is lagging behind, disintegration of the old city is slow, optimization and upgrading, quality public service resources are still heavily concentrated in the old town together. Southbank Centre has not been formed, functions of the service area space is missing. Meanwhile, peripheral group centres service was weak and inadequate accounting for city development, "suspicious" pattern could not be formed. As regards transport, with the outward expansion of cities, cities have been expanding, centripetal city traffic organization has not changed, integrated energy, chemicals and textile Yibin city, are the three core pillars of the industry. In 2014, the wuliangye brand value to 73.58 billion yuan, the city's liquor industry slip to stabilise. Promoting deep development of integrated energy, advanced equipment manufacturing industry, changning district, shale gas production capacity reached 277 million cubic metres, built the country's first independent high-yield wells and pipelines in the first section, the lead in factory production and supply to the population. 2.1-3 GDP growth figure 2.1-4 Yibin, Yibin city, Yibin city, fiscal revenue growth 2.1.4 topography terrain overall is Southwest, North-Eastern State. Low mountains and hills in the city landscape as the main ridge-and-Valley, pingba small fragmented nature picture for "water and the second land of the seven hills". 236 meters to 2000 meters above sea level in the city, low mountain, 46.6% hills 45.3%, pingba only 8.1%. 2.1.5 development of Yibin landscapes and distinctive feature in the center of the city, with limitations, and spatial structure of typical zonal group, 2012-cities in building with an area of about 76.2km2. From city-building situation, "old town-the South Bank" Center construction is lagging behind, disintegration of the old city is slow, optimization and upgrading, quality public service resources are still heavily concentrated in the old town together. Southbank Centre has not been formed, functions of the service area space is missing. Meanwhile, peripheral group centres service was weak and inadequate accounting for city development, "suspicious" pattern could not be formed. As regards transport, with the outward expansion of cities, cities have been expanding, centripetal city traffic organization has not changed, 第5章 无线通信传输理论 一、实践活动 去当地的中国电信和广播电视台实地参观无线传输系统，了解无线系统有那些设备,了解有哪些业务,比较有线传输系统的区别。 二、思考与复习题 1、 简述无线电波的传播方式及其特点。 2、 简述无线电波的传播特性。 3、 介绍传输媒质对电波传播的影响。 4、解释自由空间和自由空间损耗的概念 5、惠更斯一费涅耳原理的基本思想是什么,解释费涅耳区的概念。 6、 K值是怎样定义的,温带地区K值变化范围为多大,K值的变化意味着什么, 7、大气和地面造成了几种衰落型式,衰落产生的原因以及抗衰落所采用的技术。 8、微波和卫星通信中将采用哪些抗衰落技术, 9、无线(如卫星、移动通信)通信为什么要采用多址技术,常见的多址技术有哪几种, 10、简述码分多址的工作原理。 11.已知发信功率P =10W，工作频率f = 4. 2GHz，两微波站相距50km, G =1000倍，G TTR=38dB , 收、发天线的馈线损耗[Lr]= [Lt] =3dB, 求:在自由空间传播条件下接收机的输入功率电平和输入功率。 12、已知两微波站相距46km，反射点离发端18km，且天线高度恰好满足自由空间的余隙h，通信频率为6GHz，地面反射因子ρ?0.7。 0 求:天线的自由空间的余隙h和衰落因子[L] 0k 13、某微波传输信道，发射天线的增益为32dB，接收天线的的增益为20dB，收发距离为24500 km，载波中心频率为6.904GHz， 求:该信道的基本传输损耗为多少?若发射功率为25w,接收机的接收到的功率为多少? 14.已知在自由空间传输条件下接收机的收信功率P=-35dBm，在传输途中有如图5-7所示的刃形障碍物，且hc= -0.5F (F是第1费涅耳区半径) ，求此时收信功率电平。 11 第6章 移动通信传输信道的特性 一、实践活动(了解身边的移动通信网络) 1、为了建立对移动通信系统整体、直观的印象，实地参观中国移动的GSM系统、中国 联通的CDMA系统，了解基站有哪些设备,了解有哪些交换设备,了解有哪些业务, 2、去手机生产厂家实地参观，了解手机的生产工艺 流程 快递问题件怎么处理流程河南自建厂房流程下载关于规范招聘需求审批流程制作流程表下载邮件下载流程设计 ，了解手机的外形、功能、业务辐射及构造原理。 3、特别留心一下学校周边的各种基站及天线，询问有关技术人员和老师，它们都有哪些设备，各自有什么作用。 4、网搜索有关2.5G和3G的发展。请访问:华为网站http : //www. huawei. com. cn、中兴网站http: //www. zte. com. cn, 或以2.5G, 3G为关键词到百度网站上搜索一下，重点关心内容为:国内外有关2.5G, 3G的技术发展与市场;为什么要建设2.5G;2.5G和2G的差别;3G会给我们带来什么;未来3G标准融合的可能性;中国目前3G的发展。 二、思考与复习题 1、何谓移动通信, 2、移动通信的信道有哪些特点, 3、移动通信的工作方式有哪几种,每种有何特点, 4、GSM移动通信系统由几部分组成,每部分的作用是什么, integrated energy, chemicals and textile Yibin city, are the three core pillars of the industry. In 2014, the wuliangye brand value to 73.58 billion yuan, the city's liquor industry slip to stabilise. Promoting deep development of integrated energy, advanced equipment manufacturing industry, changning district, shale gas production capacity reached 277 million cubic metres, built the country's first independent high-yield wells and pipelines in the first section, the lead in factory production and supply to the population. 2.1-3 GDP growth figure 2.1-4 Yibin, Yibin city, Yibin city, fiscal revenue growth 2.1.4 topography terrain overall is Southwest, North-Eastern State. Low mountains and hills in the city landscape as the main ridge-and-Valley, pingba small fragmented nature picture for "water and the second land of the seven hills". 236 meters to 2000 meters above sea level in the city, low mountain, 46.6% hills 45.3%, pingba only 8.1%. 2.1.5 development of Yibin landscapes and distinctive feature in the center of the city, with limitations, and spatial structure of typical zonal group, 2012-cities in building with an area of about 76.2km2. From city-building situation, "old town-the South Bank" Center construction is lagging behind, disintegration of the old city is slow, optimization and upgrading, quality public service resources are still heavily concentrated in the old town together. Southbank Centre has not been formed, functions of the service area space is missing. Meanwhile, peripheral group centres service was weak and inadequate accounting for city development, "suspicious" pattern could not be formed. As regards transport, with the outward expansion of cities, cities have been expanding, centripetal city traffic organization has not changed, integrated energy, chemicals and textile Yibin city, are the three core pillars of the industry. In 2014, the wuliangye brand value to 73.58 billion yuan, the city's liquor industry slip to stabilise. Promoting deep development of integrated energy, advanced equipment manufacturing industry, changning district, shale gas production capacity reached 277 million cubic metres, built the country's first independent high-yield wells and pipelines in the first section, the lead in factory production and supply to the population. 2.1-3 GDP growth figure 2.1-4 Yibin, Yibin city, Yibin city, fiscal revenue growth 2.1.4 topography terrain overall is Southwest, North-Eastern State. Low mountains and hills in the city landscape as the main ridge-and-Valley, pingba small fragmented nature picture for "water and the second land of the seven hills". 236 meters to 2000 meters above sea level in the city, low mountain, 46.6% hills 45.3%, pingba only 8.1%. 2.1.5 development of Yibin landscapes and distinctive feature in the center of the city, with limitations, and spatial structure of typical zonal group, 2012-cities in building with an area of about 76.2km2. From city-building situation, "old town-the South Bank" Center construction is lagging behind, disintegration of the old city is slow, optimization and upgrading, quality public service resources are still heavily concentrated in the old town together. Southbank Centre has not been formed, functions of the service area space is missing. Meanwhile, peripheral group centres service was weak and inadequate accounting for city development, "suspicious" pattern could not be formed. As regards transport, with the outward expansion of cities, cities have been expanding, centripetal city traffic organization has not changed, 5、指出移动通信的传输特点。 6、阐述频分双工(FDD)和时分双工(TDD)的区别和各自特点。 7、叙述典型移动通信系统的主要工作频段。 8、介绍产生阴影效应与多径效应的原因。 9、给出按照多径信道特征参数的信道分类。 10、简述噪声的分类和特性 11、解释邻道干扰、同道干扰、互调干扰、远近效应和符号间干扰。 12、基站天线有效高度为50m，移动台天线高度为2m，由r=10km和要求的有用信号和干0 扰信号的比[S/I ]=22 dB，试求同道再用距离D. 13、当一个基站同时接收两个移动台发来的信号，一个移动台离基站为0.1km，另一个离基站为10km ，单位路径损耗相等，试求其近端—远端比干扰. 14、已知市区移动台的工作频率为350MHz，其接收机带宽为16kHz，试求接收机输入端的人为噪声功率为多少dBw? 15、某一移动信道，工作频段为450 MHz，基站天线高度为50 m，天线增益为10 dB，移动台天线高度为3m，天线增益为0 dB;在市区工作，传播路径为中等起伏地，通信距离为10km。试求:( (1)传播路径损耗中值; (2)若基站发射机送至天线的信号功率为20 W，求移动台天线得到的信号功率中值 16、已知干扰的频率f=150.2MHz 、f=150.1MHz、f=150.0MHz。问当某用户移动台的接ABC 收频率为150.3MHz时，能否产生三阶互调干扰? 17、基站天线有效高度为50m，移动台天线高度为2m，由r=10km和要求的有用信号和干0 扰信号的比[S/I ]=22 dB，试求同道再用距离D 第7章 微波通信传输信道的特征 一、实践活动 实地参观当地的中国电信长途微波传输机房，询问有关技术人员进一步了解微波中继通信总体设计情况。 二、思考与练习 1、简述微波中继传输应用情况 2、简述余隙的概念以及在工程中的选择条件。 3、简述微波通信常用频率。 4、简述微波常用天线的种类及其特点。 5、数字微波的线路噪声分为哪几种,各包括哪几种, 6、微波天线高度的选取应考虑哪些因素,hc =0. 577.F1 7、.已知微波发信功率4W，工作频率4000MHZ，微波两站相距50km，发射天线的增益为30dB，接收天线的的增益为25dB，收发两端馈线系统损耗[Lr]=2 dB, [Lt]=1 dB，传输路径上障碍物的尖峰好落h=0，求:实际微波接收机能接收的功率[P] cR 8、若两相邻微波站A、B相距48km，反射点距A站18km和24km，求此两种情况下的地面突起高度h和h各是多少,若又考虑大气折射时的K值为4/3，再求上述两种情况下的等效地12 面突起高度h和h各是多少m, e1e2 9、设微波中继通信采用f,10GHz，站距为50km，路径为光滑球形地面，收发天线最小高度，如图7-12所示。求(1)不计大气折射K=1，保证自由空间余隙h时，等高收发天线0 的最小高度;(2)在k,4/3时，收发天线最小高度。 10、已知某数字微波通信系统的技术指标如下: 理论载噪比,20dB，固定恶化=4 dB，在室温下(290K)，接收机的噪声系数,2.1，integrated energy, chemicals and textile Yibin city, are the three core pillars of the industry. In 2014, the wuliangye brand value to 73.58 billion yuan, the city's liquor industry slip to stabilise. Promoting deep development of integrated energy, advanced equipment manufacturing industry, changning district, shale gas production capacity reached 277 million cubic metres, built the country's first independent high-yield wells and pipelines in the first section, the lead in factory production and supply to the population. 2.1-3 GDP growth figure 2.1-4 Yibin, Yibin city, Yibin city, fiscal revenue growth 2.1.4 topography terrain overall is Southwest, North-Eastern State. Low mountains and hills in the city landscape as the main ridge-and-Valley, pingba small fragmented nature picture for "water and the second land of the seven hills". 236 meters to 2000 meters above sea level in the city, low mountain, 46.6% hills 45.3%, pingba only 8.1%. 2.1.5 development of Yibin landscapes and distinctive feature in the center of the city, with limitations, and spatial structure of typical zonal group, 2012-cities in building with an area of about 76.2km2. From city-building situation, "old town-the South Bank" Center construction is lagging behind, disintegration of the old city is slow, optimization and upgrading, quality public service resources are still heavily concentrated in the old town together. Southbank Centre has not been formed, functions of the service area space is missing. Meanwhile, peripheral group centres service was weak and inadequate accounting for city development, "suspicious" pattern could not be formed. As regards transport, with the outward expansion of cities, cities have been expanding, centripetal city traffic organization has not changed, integrated energy, chemicals and textile Yibin city, are the three core pillars of the industry. In 2014, the wuliangye brand value to 73.58 billion yuan, the city's liquor industry slip to stabilise. Promoting deep development of integrated energy, advanced equipment manufacturing industry, changning district, shale gas production capacity reached 277 million cubic metres, built the country's first independent high-yield wells and pipelines in the first section, the lead in factory production and supply to the population. 2.1-3 GDP growth figure 2.1-4 Yibin, Yibin city, Yibin city, fiscal revenue growth 2.1.4 topography terrain overall is Southwest, North-Eastern State. Low mountains and hills in the city landscape as the main ridge-and-Valley, pingba small fragmented nature picture for "water and the second land of the seven hills". 236 meters to 2000 meters above sea level in the city, low mountain, 46.6% hills 45.3%, pingba only 8.1%. 2.1.5 development of Yibin landscapes and distinctive feature in the center of the city, with limitations, and spatial structure of typical zonal group, 2012-cities in building with an area of about 76.2km2. From city-building situation, "old town-the South Bank" Center construction is lagging behind, disintegration of the old city is slow, optimization and upgrading, quality public service resources are still heavily concentrated in the old town together. Southbank Centre has not been formed, functions of the service area space is missing. Meanwhile, peripheral group centres service was weak and inadequate accounting for city development, "suspicious" pattern could not be formed. As regards transport, with the outward expansion of cities, cities have been expanding, centripetal city traffic organization has not changed, 接收机的等效带宽=26.8MHz，试计算出该系统的门限载波信号功率电平值 11、已知一个6GHz的SDH 155Mbit/s系统的传输信道参数如下: 发射机的发射电平等于42dBm，收、发端天线增益各为43dB，单端馈线损耗[L],2.5dB，f附加损耗[Lc]=2.5dB，信道的频带宽度为25.833MHz，实际门限载噪比[C/N],25.1dB，噪声系数,2dB，收发两端之间的距离,60km。试计算出系统的平衰落储备是多少, 第8章 卫星通信传输线路的特征 一、实践活动 调研卫星通信应用市场，了解卫星通信有那些业务,比较与其他通信的区别。 二、思考与习题 1、简要叙述卫星通信的主要优缺点;与光纤通信相比，你认为卫星通信系统适合什么样的应用领域。 2、 卫星通信系统由哪几部分组成? 它们各自的作用如何? 卫星转发器的主要功能是什 么? 3、 卫星通信使用哪些工作频段? 原因是什么? 目前使用较多的卫星通信业务主要有哪些? 4、 通信卫星有哪些运行轨道? 影响静止卫星轨道的有哪些因素? 5、有哪几种干扰在卫星通信中必须考虑? 它们的产生原因是什么, 6、在接收机前端滤波器输出端，测试得到的噪声功率为0.03pW，而滤波器等效噪声带宽为 10MHz，试确定等效噪声温度。 7、试解释卫星接收系统G/T值的含义。某地球站使用5m的天线，工作频率为12Hz，天线 (天线与接收机之间的馈线 噪声温度为100 K，接收机前端噪声温度为120 K，试计算G/T值 损耗忽略)。 8、C频段(6.1GHz)地球站发射天线增益为54dB，发射机输出功率为l00W。卫星与地球站相 距37500km，卫星与地球站收发馈线损耗均为[Lr]=1 dB、馈线损耗[L]=2 dB，[L]=0.8 dB、 tR[La]=1.1dB卫星接收天线增益为398倍，转发器噪声温度为500K，卫星接收机带宽为 36MHz。试计算下列数值:求卫星输入噪声功率电平dBW和卫星输入载噪比[C/N]。 9、—个12GHz的下行卫星系统参数如下:卫星输出功率为10W，馈线损耗1dB，天线增益为 35.2dB;卫星到地球站距离d,40000km，大气层附加损耗为0.3dB。接收地球站天线增益为 51.2dB，馈线损耗0.5dB，G/T,26.2(dB/K)。求下行线路的[C/N]。 D 10、在IS-IV号卫星通信系统，其卫星有效全向辐射功率[EIRP] =34.2dBw，接收天线增益 S [G]=20.7dB。又知道某地球站发射天线增益[G],60.1 dB，发送馈线损耗[L],0.4 dB， RSTEtE发射机输出功率P=3.9kW，地球站接收天线增益[G]=60.0dB,接收馈线损耗[Lr]=0.1 dB。 TEREE试计算卫星接收机输入端的载波接收功率[C]和地球站接收机输入端的载波接收功率[C]。 SE11、已知条件如图8-17所示，设卫星转发器工作在单载波状态，卫星和地球站的馈线损耗 Lr]=1 dB、馈线损耗[L]=2 dB，[L]=0.2 dB、[La]=1 dB，分别求出卫星线路的上行[C/T]tRU 和下行[C/T]的值。 D integrated energy, chemicals and textile Yibin city, are the three core pillars of the industry. In 2014, the wuliangye brand value to 73.58 billion yuan, the city's liquor industry slip to stabilise. Promoting deep development of integrated energy, advanced equipment manufacturing industry, changning district, shale gas production capacity reached 277 million cubic metres, built the country's first independent high-yield wells and pipelines in the first section, the lead in factory production and supply to the population. 2.1-3 GDP growth figure 2.1-4 Yibin, Yibin city, Yibin city, fiscal revenue growth 2.1.4 topography terrain overall is Southwest, North-Eastern State. Low mountains and hills in the city landscape as the main ridge-and-Valley, pingba small fragmented nature picture for "water and the second land of the seven hills". 236 meters to 2000 meters above sea level in the city, low mountain, 46.6% hills 45.3%, pingba only 8.1%. 2.1.5 development of Yibin landscapes and distinctive feature in the center of the city, with limitations, and spatial structure of typical zonal group, 2012-cities in building with an area of about 76.2km2. From city-building situation, "old town-the South Bank" Center construction is lagging behind, disintegration of the old city is slow, optimization and upgrading, quality public service resources are still heavily concentrated in the old town together. Southbank Centre has not been formed, functions of the service area space is missing. Meanwhile, peripheral group centres service was weak and inadequate accounting for city development, "suspicious" pattern could not be formed. As regards transport, with the outward expansion of cities, cities have been expanding, centripetal city traffic organization has not changed, integrated energy, chemicals and textile Yibin city, are the three core pillars of the industry. In 2014, the wuliangye brand value to 73.58 billion yuan, the city's liquor industry slip to stabilise. Promoting deep development of integrated energy, advanced equipment manufacturing industry, changning district, shale gas production capacity reached 277 million cubic metres, built the country's first independent high-yield wells and pipelines in the first section, the lead in factory production and supply to the population. 2.1-3 GDP growth figure 2.1-4 Yibin, Yibin city, Yibin city, fiscal revenue growth 2.1.4 topography terrain overall is Southwest, North-Eastern State. Low mountains and hills in the city landscape as the main ridge-and-Valley, pingba small fragmented nature picture for "water and the second land of the seven hills". 236 meters to 2000 meters above sea level in the city, low mountain, 46.6% hills 45.3%, pingba only 8.1%. 2.1.5 development of Yibin landscapes and distinctive feature in the center of the city, with limitations, and spatial structure of typical zonal group, 2012-cities in building with an area of about 76.2km2. From city-building situation, "old town-the South Bank" Center construction is lagging behind, disintegration of the old city is slow, optimization and upgrading, quality public service resources are still heavily concentrated in the old town together. Southbank Centre has not been formed, functions of the service area space is missing. Meanwhile, peripheral group centres service was weak and inadequate accounting for city development, "suspicious" pattern could not be formed. As regards transport, with the outward expansion of cities, cities have been expanding, centripetal city traffic organization has not changed,