【正文】 終端問(wèn)題和暴露終端問(wèn)題。任選一個(gè)時(shí)隙，網(wǎng)絡(luò)中有節(jié)點(diǎn)在發(fā)送數(shù)據(jù)的概率 當(dāng)有節(jié)點(diǎn)在發(fā)送數(shù)據(jù)包時(shí)，數(shù)據(jù)包發(fā)送成功的概率 數(shù)據(jù)包發(fā)送成功和發(fā)送失敗所需的時(shí)間為什么在數(shù)據(jù)包長(zhǎng)度較長(zhǎng)時(shí)，采用RTS/CTS模式更合理？“隱藏終端”多發(fā)生在大型單元中（一般在室外環(huán)境），這將帶來(lái)效率損失，并且需要錯(cuò)誤恢復(fù)機(jī)制。五、實(shí)驗(yàn)原理雙絞線概述雙絞線由兩根具有絕緣保護(hù)層的銅導(dǎo)線組成。分離4對(duì)電纜，按照所做雙絞線的線序標(biāo)準(zhǔn)（T568A或T568B）排列整齊，并將線弄平直。包括：文件夾共享（學(xué)生自做）、打印機(jī)共享（教師演示）、共享文件夾的映射（學(xué)生自做）四、實(shí)驗(yàn)原理對(duì)于一二十臺(tái)計(jì)算機(jī)組成的小型局域網(wǎng)環(huán)境，當(dāng)采用對(duì)等工作方式時(shí)，局域網(wǎng)中所有的工作站均裝有相同的協(xié)議棧每臺(tái)汁算機(jī)的“地位”是對(duì)等的，故稱為對(duì)等網(wǎng)?！癷pconfig”,由此查看本機(jī)的ip地址。~7步，測(cè)試網(wǎng)絡(luò)的聯(lián)通性。例如：網(wǎng)易126的郵箱()：你的郵箱地址是：用戶名，郵箱空間有2G，單封郵件附件容量為15M。（3）ARP 作用：顯示和修改IP地址與物理地址之間的轉(zhuǎn)換表。仿真參數(shù)：信源比特速率為500kbps，多徑相對(duì)時(shí)延為[0 4e06 8e06 ]秒，相對(duì)平均功率為[0369]dB，最大多普勒頻移為200Hz。前標(biāo)準(zhǔn)的QPSK星座圖，4個(gè)相位 后移動(dòng)通信系統(tǒng)信號(hào)經(jīng)過(guò)多徑信道后，相位和幅值均發(fā)生了隨機(jī)變化，信號(hào)不再分布在四個(gè)點(diǎn)附近，可以看出信號(hào)質(zhì)量很差。本實(shí)驗(yàn)主要注重微觀分集。直擴(kuò)系統(tǒng)的抗干擾能力是由接收機(jī)對(duì)干擾的抑制產(chǎn)生的，如果干擾信號(hào)的帶寬與信息帶寬相同（即窄帶），此干擾信號(hào)經(jīng)過(guò)發(fā)送機(jī)偽噪聲碼調(diào)制后將展寬為與發(fā)送信號(hào)相同的帶寬，而其譜密度卻降低了若干倍。仍用信源單元的FS信號(hào)作為示波器的外同步信號(hào)。二、實(shí)驗(yàn)內(nèi)容用示波器觀察絕對(duì)碼波形、相對(duì)碼波形。二、實(shí)驗(yàn)內(nèi)容、失鎖狀態(tài)及捕捉過(guò)程。ud的這種變化表示了環(huán)路的捕捉過(guò)程。105180。2DPSK系統(tǒng)之所能克服相位模糊現(xiàn)象，是因?yàn)樵诎l(fā)端將絕對(duì)碼變?yōu)榱讼鄬?duì)碼，在收端又將相對(duì)碼變?yōu)榻^對(duì)碼，載波相位模糊可 使解調(diào)出來(lái)的相對(duì)碼有兩種相反的狀態(tài)，但它們對(duì)應(yīng)的絕對(duì)碼是相同的。在網(wǎng)上查找資料的時(shí)候也接觸到了不少其他的編程語(yǔ)言例如VB，delphi，C等，這也讓我對(duì)這些從沒(méi)有學(xué)過(guò)的語(yǔ)言有所了解，我想這些知識(shí)對(duì)以后的實(shí)驗(yàn)工作都有幫助。要求兩臺(tái)PC機(jī)能進(jìn)行實(shí)時(shí)的字符通信，并了解工業(yè)自動(dòng)化控制中的基本通信方式。三、實(shí)驗(yàn)步驟，接通實(shí)驗(yàn)箱電源。180。通信原理實(shí)驗(yàn)報(bào)告四、實(shí)驗(yàn)總結(jié)。三、實(shí)驗(yàn)步驟本實(shí)驗(yàn)使用數(shù)字信源單元、數(shù)字調(diào)制單元和載波同步單元。用頻譜儀觀察數(shù)字基帶信號(hào)頻譜及2ASK、2FSK、2DPSK信號(hào)的頻譜。再將KKK3置為全0，觀察全0碼對(duì)應(yīng)的AMI碼和HDB3碼。實(shí)驗(yàn)原理框圖伯努利信源b(t)x(t)s(t)信道r(t)e(t)Tby(Tb)dt242。合并方式共分為三種，選擇合并、等增益合并和最大 比值合并。PSK/QPSK通信鏈路搭建與誤碼性能分析掌握基于simulink的BPSK、QPSK典型通信系統(tǒng)的鏈路實(shí)現(xiàn)，仿真BPSK/QPSK信號(hào)在AWGN信道、單徑瑞利衰落信道下的誤碼性能。fm=200。g跟a一樣。這種方法需要通過(guò)專門的電子郵件軟件才能收發(fā)郵件，最典型的微軟的OE（Outlook Express）, Mail Transfer Protocol（簡(jiǎn)單郵件傳輸協(xié)議）。在連接打印機(jī)的計(jì)算機(jī)上(假設(shè)主機(jī)名為zhao)，從“控制面板”的“打印機(jī)”中，右擊該打印機(jī)名后單擊“共享”，在出現(xiàn)的界面中選中“共享為”，輸入共享名“worknet”。從“網(wǎng)上鄰居”看到相鄰主機(jī)的名字。使用該協(xié)議的網(wǎng)絡(luò)，以“工作組”的形式劃分子網(wǎng)（計(jì)算機(jī)的歸屬），以“計(jì)算機(jī)名”區(qū)分和識(shí)別計(jì)算機(jī)。將有序的線頭順著RJ45頭的插口輕輕插入，插到底，并確保護(hù)套也被插入。雙絞線電纜比較柔軟，便于在墻角等不規(guī)則地方施工，但信號(hào)的衰減比較大。實(shí)驗(yàn)三 動(dòng)態(tài)源路由協(xié)議路由選擇驗(yàn)證一、實(shí)驗(yàn)?zāi)康牧私釪SR路由協(xié)議的優(yōu)缺點(diǎn)。由于節(jié)點(diǎn)3是節(jié)點(diǎn)1的一個(gè)隱終端，節(jié)點(diǎn)1無(wú)法通過(guò)物理載波檢測(cè)偵聽到節(jié)點(diǎn)3的發(fā)送，且節(jié)點(diǎn)3在節(jié)點(diǎn)2的傳輸范圍外，節(jié)點(diǎn)3無(wú)法通過(guò)虛擬載波檢測(cè)延遲發(fā)送，所以在節(jié)點(diǎn)1傳輸數(shù)據(jù)的過(guò)程中，節(jié)點(diǎn)3完成退避發(fā)送時(shí)將引起沖突。二、實(shí)驗(yàn)結(jié)果Node: 1, Layer: AppCbrClient,(4)Server address: 55 Node: 1, Layer: AppCbrClient,(4)First packet sent at [s]: Node: 1, Layer: AppCbrClient,(4)Last packet sent at [s]: Node: 1, Layer: AppCbrClient,(4)Session status: Not closed Node: 1, Layer: AppCbrClient,(4)Total number of bytes sent: 5120000 Node: 1, Layer: AppCbrClient,(4)Total number of packets sent: 10000 Node: 1, Layer: AppCbrClient,(4)Throughput(bits per second): 409600 Node: 1, Layer: AppCbrClient,(3)Server address: 54 Node: 1, Layer: AppCbrClient,(3)First packet sent at [s]: Node: 1, Layer: AppCbrClient,(3)Last packet sent at [s]: Node: 1, Layer: AppCbrClient,(3)Session status: Not closed Node: 1, Layer: AppCbrClient,(3)Total number of bytes sent: 5120000 Node: 1, Layer: AppCbrClient,(3)Total number of packets sent: 10000 Node: 1, Layer: AppCbrClient,(3)Throughput(bits per second): 409600 Node: 1, Layer: AppCbrClient,(2)Server address: 53 Node: 1, Layer: AppCbrClient,(2)First packet sent at [s]: Node: 1, Layer: AppCbrClient,(2)Last packet sent at [s]: Node: 1, Layer: AppCbrClient,(2)Session status: Not closed Node: 1, Layer: AppCbrClient,(2)Total number of bytes sent: 5120000 Node: 1, Layer: AppCbrClient,(2)Total number of packets sent: 10000 Node: 1, Layer: AppCbrClient,(2)Throughput(bits per second): 409600 Node: 1, Layer: AppCbrClient,(1)Server address: 52 Node: 1, Layer: AppCbrClient,(1)First packet sent at [s]: Node: 1, Layer: AppCbrClient,(1)Last packet sent at [s]: Node: 1, Layer: AppCbrClient,(1)Session status: Not closed Node: 1, Layer: AppCbrClient,(1)Total number of bytes sent: 5120000 Node: 1, Layer: AppCbrClient,(1)Total number of packets sent: 10000 Node: 1, Layer: AppCbrClient,(1)Throughput(bits per second): 409600 Node: 1, Layer: AppCbrClient,(0)Server address: 51 Node: 1, Layer: AppCbrClient,(0)First packet sent at [s]: Node: 1, Layer: AppCbrClient,(0)Last packet sent at [s]: Node: 1, Layer: AppCbrClient,(0)Session status: Not closed Node: 1, Layer: AppCbrClient,(0)Total number of bytes sent: 5120000 Node: 1, Layer: AppCbrClient,(0)Total number of packets sent: 10000 Node: 1, Layer: AppCbrClient,(0)Throughput(bits per second): 409600 Node: 51, Layer: AppCbrServer,(0)Client address: 1 Node: 51, Layer: AppCbrServer,(0)First packet received at [s]: Node: 51, Layer: AppCbrServer,(0)Last packet received at [s]: Node: 51, Layer: AppCbrServer,(0)Average endtoend delay [s]: Node: 51, Layer: AppCbrServer,(0)Session status: Not closed Node: 51, Layer: AppCbrServer,(0)Total number of bytes received: 5102592 Node: 51, Layer: AppCbrServer,(0)Total number of packets received: 9966 Node: 51, Layer: AppCbrServer,(0)Throughput(bits per second): 408219 Node: 52, Layer: AppCbrServer,(1)Client address: 1 Node: 52, Layer: AppCbrServer,(1)First packet received at [s]: Node: 52, Layer: AppCbrServer,(1)Last packet received at [s]: Node: 52, Layer: AppCbrServer,(1)Average endtoend delay [s]: Node: 52, Layer: AppCbrServer,(1)Session status: Not closed Node: 52, Layer: AppCbrServer,(1)Total number of bytes received: 5102592 Node: 52, Layer: AppCbrServer,(1)Total number of packets received: 9966 Node: 52, Layer: AppCbrServer,(1)Throughput(bits per second): 408233 Node: 53, Layer: AppCbrServer,(2)Client address: 1 Node: 53, Layer: AppCbrServer,(2)First packet received at [s]: Node: 53, Layer: AppCbrServer,(2)Last packet received at [s]: Node: 53, Layer: AppCbrServer,(2)Average endtoend delay [s]: Node: 53, Layer: AppCbrServer,(2)Session status: Not closed Node: 53, Layer: AppCbrServer,(2)Total number of bytes received: 3926016 Node: 53, Layer: AppCbrServer,(2)Total number of packets received: 7668 Node: 53, Layer: AppCbrServer,(2)Throughput(bits per second): 314112 Node: 54, Layer: AppCbrServer,(3)Client address: 1 Node: 54, Layer: AppCbrServer,(3)First packet received at [s]: Node: 54, Layer: AppCbrServer,(3)Last packet received at [s]: Node: 54, Layer: AppCbrServer,(3)Average endtoend delay [s]: Node: 54, Layer: AppCbrServer,(3)Sessio