移动通信1,考试题

移动通信1,考试题 1.移通信是指通信动动动动动动动20.衰落是影响通信量的主动动动动元,既保网中移用之的动动动动动动动动动动 双方至少有一方在移中行信息动动动动动动要因素。快衰落的深度可达30-40dB,分集通信,又保移用和有用动动动动动动动动动动 的与交,包括移体通动动动动动动动动动动动动动接收抗衰落的一有效动动动动动动动动动动动动措施。之的通信。动动动动动MSC在网中起控制和管理作 信,移体和固定点之的通动动动动动动动动动动21.分集接收是指接收端动动动它收用。 信。主要特点:1.移通信必利用动动动动动动动10.越区切:当移台从动动动动动动动到的多个衰落特性互相独立的信号行动动无波行信息动动动动动动动动动 2.移通信动动动一个小区入另一相的小区,动动动动动动动动动动特定的理,以降低信号动动动动动动动动动动平是在的干境中运行的动动动动动动动动动动动 3. 其工作率及基站与移交动动动动动动动动动动起伏的动动动动动动动动动动法。分集的两重含:一是分散动动,移通信可以利用的源非常有动动动动动动动动动动动动动动动中心所用的接路必从离的动动动动动动动动动是接收端能动动动动动动动动动得多个独立的、限,而移通信量的需求却与日动动动动动动动动动动动动动增。俱4.小区到正在入的小区。动动动动动动动动动动动携动动动动动动动动动动同一信息的衰落信号,移通信系的网构多多动动动动动动动动动动动动动越区切必准确可靠,且不动动动动动动动动动动而是集中理,即接收机把收动动动动动动动动动动动动动动动动动动动动动,网管理和控制必有效。5.移通动动影响通信中的音量。它是蜂动动动动动动动动动到的多个独动动动动动动动动动动立的衰落信号信必适于在移境中使用。动动动动动动动动动动动动动动动移通信系中的技,是动动动动动动动动动动动动动行合并以降低衰落的影响。分集方式:1.宏2.移通信分:动动动动动动1.按多址方式移通信系利用众多小区动动动动动动动动动动动动分集，多基站分集,主要用于蜂通信动动动可分分多址、分多址和分多址,动动动动动动动动动动动动动动动动2.动动动动动动动动动动大面覆盖的必要条件。系中,是一减小动动动动动动动动动动动动慢衰落按工作方式可分同工、异动动动动动动动动动11.网构的成部分:动动动动动动动动影响的分集技,动动2.微分集是一减小动动动工、异双工和半双工,动动动动动动动动3.按信号形式可分移交中心，动动动动动动MSC,,基站分系动快衰落影响的分集技,分动动动动动动动六:1空动动动动动动动动动模网和数字网,，BSS,，含基站控制器，BSC,基站收动分集2.动率分集3.极化分集4.动分量分集5.3.数字通信的主 要点 综治信访维稳工作要点综治信访维稳工作要点2018综治平安建设工作要点新学期教学工作要点医院纪检监察工作要点 :动动动1.动动利信台BTS,、移台动动MS、属位置寄存器动动动动动动动角度分集6.动动分集用率高,有利于提高系容量,动动动动2.能提供多HLR、位置寄存器动动动动动动动VLR、寄动动动动动22.合并方式:1.动动 式合并2.最大动动动动动动动动动动动动动动动动服,提高通信系的通用性。3.抗噪存器EIR、中心动动动动AUC和操作中动动动比合并动动动3.等增益合并声、抗干和抗多径衰落的能力动动。强4能动动心，OMC,。23.在相同分集重数情况下,以最更有效、灵活的网管理和控制。动动动动动动动5.便于动12.无接口采用放系动动动动动动动动大比合并动动动动动动动动动动方式改善信噪比动通信的安全保密。6.可降低成本动动动动动动动动动动动动动动动动互参考模型的概念来定最多,等增益合并方式次之,在分集重数M以及减小用手机的体和重量。动动动动动动动动动动其模型。它移境中的动动动动动动动动动动动动动动动动动动动动动动动动少,等增益合并的信噪4.无通信的方式动动动动动动动动通信量和可靠性具有重要动动动动动动动动动动比改善接近最大比合并动动动动动动动动。式合分向和双向。向动动动动动动动动动动动动动动的影响。模型分三:物理、数动动动动动动动并所得到的信噪比改善量最少,只用于无呼系。双向有动动动动动动动动动动动动据路、网。动动动动动动动动24.动动动动动动动动动动动督位元所占比例越大,动动动动动动工、双工和半双工三工作方式。13.移交中心是移动动动动动动动动，,能力就越动动动动动动动动。强 同工是指通信双方使用相同的率动动动动动动动动动动动动动动动动f1通信网中使用的交机,与动动动动动动动动动动25.多址技主要解决众动动动动动动工作,送不接收,接收动动动动动动动动动动常交机的不同之是:动动动动动动动动动动动MSC除了要完多用动动动动动动动动动动动动动动动动动如何高效共享定源的。不送。异工通信方式是动动动动动动动动动动动动成常交机的所有功能外,动动动动动动动动动动26.动动动动动动动量的大小用量来量指收信机使用两个不同的动动动动动动动动动动它移性管理和无源管理。动动动动动动动动动动动动动动动动度。量又分动动动动动动动动动动动动流入量和动动动动动动动动动动动动率分行送和接收。双工14.信道按媒分有动动动动动动动动完成量。动动动动动动动动动动动动流入量的大小通信是指通信双方可同行消息动动动动动动动信道和无信道。波播方式:路径动动动动动动动动动动动动动1从取决于位动动动动动动动动动动动动动动内平均生的呼叫次数λ和的工作方式。双工通信一般使用一道,动动动动动动动动动动动动动动动射天直接到达接收天的每次呼叫平均占用信道动动S。动动然λ和S的加以施分双工工作方式。动动动动动动动动动动动动波称直射波,它是动动动动动动动VHF和UHF动段的主大都会使量加大动动动动动 A=λ*S ,λ，次/小动动动动动工作方式使用方便,同普通有相要播方式,路径动动动动动动动2动动动动动动波地面反动,。S，小动/次,A，,动动动动似,接收和射可同行。动动动动动动动动射到达接收天,称地面反射波,路径动动动动动动动动动动动动327.动动动动动动动动动动失量占流入量5.常用移通信系:动动动动动动1.无动动动的波沿地球表面播,称地表面波。动动动动动动动动动动动动动动动动动的比率即呼动动动动动动动动动叫失的比率,呼系，向通信,动动动动动动动2.蜂移通信系动动动动动动动3.无15.动动动动动动动动动射耗在情况下,称呼率。动动动动动动动动动动动动也称通信网的动动动动系4.集群移通信系动动动动动5.移星通动动动动动动动动动动波的直射路径上存在各障碍物,服动动动动动动动等,呼率B越小,成功呼叫的概率信系动6.分无网动动动动由障碍物引起的附加播耗。动动动动动就越大用就越意。动动动动动动B=(A-A0)/A=(λ-λ0)/ λ6.蜂通信网把整个动动动动动动动动16.直射波、反射波或散射波在接 服区域划分成若干小的动动动动动动动动动动动收地点形成干,使信号生涉动动动动动深度28.完成量就是通信动动动动动动动区域,各小区均用小功率的射机行动动动动动且快速的衰落。由于移台的不动动动动动断网同被动动动动动动动动动动动占用信道数的平覆盖,多小区像蜂一能动动动动动动动动动动运,波播路径上的地形、动动动动动动动动动动动动均,表动动动动动动动动动动动动动动示了通信网的繁忙程度。布任意形状的服地区。动动动动动动动动动动动地物是不断化动动动动动动动动的,因而局部29.忙动动动动动动动量公式 7.相小区不允使用动动动动动动动动中动动动动动动动动动动动动动也是化的化所造成a=C*T*k*1/3600 C，次/天, T，秒/相同的道,否会生相互干动动动动动动动动动动动动(同道干)动,的衰落比多径效所引起的动动动动动动动快衰次,K(集中系数)任一小区所使用的率,在其它动动动动动动动落要慢得多,所以称动动动动动慢衰落。30.在服区面一定的动动动动动动动区群相的小区中可以再用,动动动动动动动动动动17.多径衰落的信号包服从动动动情况下,正六动动动动动动动动形小区的形状最动动动动动动动动动动动就是率再用,率再用是瑞利分布,故把多径衰落称动动动动动动动动接近理想的形,用它覆盖整动动动动动动动动蜂通信网解决用增多而动动动动动动动动动动动动瑞利衰落。了动动动动动动动动防止因衰落引个服区所需的基站数动动动动动动动动动动最少,被有限制的重大突破。动动动动动动动动动动起的通信中断,在信道中,必动动动动动动也就最动动动动动动动动动动动动。区群成足两个8.小区越小,位面可容动动动动动动动使信号的动动动动动动动动动动动动动动动平留有足的余量,以使中断率条件:一是区群之可以接,且动动动动动动动的用数越多,即系的率利用率动动动动动动动动动动动动动动R小于定指。动动动动动动动动动动动动平余量称无空隙无重叠地行覆盖,动动动动动动动动二是越高。小区分裂是蜂通信系在运行动动动动动动动动动动动动衰落。接之后的区群保各个相同信动动动动动动动动动动动动动动动动动动动动动动程中适需求的增而逐18.多径动动动动动动动动散象将致道小区之的动动动动动动动动动距离相等。足步提高其容量的独特方式。基群中的小区数率性衰落,即信道不同动动动动动动动动动动动动上述条件的区群形状和区群内的小区数不是越小,系所需划分的率数越小,动动动动动动动动动动动动动动动动动动动动动率成分有不同的响。若信号任意的。N=i+j+ij每个率所含的道数越多。动动动动动动动动动动动动大,就会引起重的动动动动动动失真。31.群小区数N越大,同信道小区9.移交中心，动动动动动动MSC,是移动19.直射波播动动动动动动距离,自的距离就越,抗同干的性动动动动动动动动动通信网和公共交网的接口动动动动动动动动动身动动动动动动动动动动率越高,耗越大。能也就越好。 32.信道分配的方式主要有两:动动1.在控制系的控制下,动动动动动动 一是分区分动动动动动动动动动配置法,二是等将任一入动动动动动动动动动盒出接通 距离配置法,分区分动动动动动动配置法所遵2.把来自用动动动动动动动或中的 循的原动动动动动动动动动是:尽量减小占用各不同的入信号和消息动动动动动动动动动动动动 的段,以提高段的利用动动动动动动动动动动动动成一的机动动动动动动动内信号 率,同一区群内不能使用相同的信道,以避3.动动动动动动动动动动动动通信网的运行,管理和 免同干,小区动动动动动动动动动动内采用无 三互的相容信道,以动动动动动动动动动动动动动动动动动动避免互干。33.等距配动动动动动动动置法是按 等动动动动动动动动动动动率隔来配置信道的, 只要动动动动动动动动动动动距的足大,就可以 有效地避免动动动动动道干。 34.蜂状的小区制是动动动动动动动 目前大容量公共移通信网的主动动动动动动 要覆盖方式。 35.交机的成:交动动动动动动动动 网、接口和控制系成,动动动动动动动动动动动动 交网的作用是在控制系动动动动动动动动动动动动 的控制下,将任一入与动动动动动动动动动动出接通。36.控制系主要路的动动动动动动动动接控制,另外通信网动动动动动动动动动动动动动 的运行、管理和。动动动 37.蜂通信网的三大特动动动动动动动动动点:率再用、小区分裂、越区切。区动动动动动动动动动动动动动动动动群所含的小区数越少,率再用动动动动动动动动动距离越短,相区群中使用相同率的小区之动动动动动动动动动动动动动动动的同道干越。动动强 38.GSM动动动动动动动动动动信分:、 动动动动动动动动动动动动动急呼叫、短消息、可 文介入、智能用送、动动动动动动动动动真。 39.移通信道的基本特动动动动动动动动动动征:1.动动有限,它取决于使用的率源和信动动动动动动道的播特性,动动动动动2.干和噪声影响动动动动动动 大,主要是移通信工作动动动动动动动动动动 的动动动动动动动动动磁境所决定的,3.存在着多径衰落。40.网控制与管理:动动动动动动动动 接控制、移管理、无源管理。动动动动动动动动动动动41.自由空动动动动动播耗[Lfs](dB)=32.44+20lgd(km)+20lgf(MHz) 42.局部中是在动动动动动动动局部 或地点中,信号动动动动动动动平大于或小于 它的各位动动动动50%。动动动动动动动化造成的衰落动动动动动慢衰落。 43.GSM蜂系的成部动动动动动动动分:移台、基站动动动动动动动动动动动动动动动动动动子系、网子系。44.数字蜂移通信系动动动动动动动的网构,其成部分:移动动动动动动动动动动动动 动动动动动交中心，MSC,,基站分系，动动BSS,,移台，动动动MS,等。网通移交中心动动动动动动动动动MSC,与公共交网动动动动PSTN,动动动动合数字网ISDN,以及公共数据网PDN相接。动动动动动动播距离:d=4.12(?hr+?(ht)) 45.什叫动动动动动动动多径衰落, 由于信号播的路径不少,到动动动动动动动动动 达用接收动动动动动动动动动动动动端的不一,造 成用信号接收效动动动动动动动动动果不同 46.分集接收,是指接收端动动它收到的多个衰落特征互相独立的信号行动动特定的理,以降低信号动动动动动动动动动动动动动动动动平起伏的法。47.分集方式,移通信系动动动动动用到的两分集方式:动动动动动动动动动动动动动宏分集,微分集48.交机的作用动动动动动动,