第2章數(shù)據(jù)通信基礎

1、數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎1數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎2數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎3主機主機CCPCCPLANPrinterPrinterTerminal主機主機LAN數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎4數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎5數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎6 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎7 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎8數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎9數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎10數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎11數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎12數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎13s s( (a a) )s s( (t t) )l li im

2、ma at t 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎14)2sin()(ftAtst ts s( (t t) )，T T) )s s( (t t數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎15數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎16數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎17)5(2sin(51)3(2sin(31)2sin()(111tftftfts數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎18數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎19數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎20 TnTnTnnndtnfttgTbdtnfttgTadttgTccTfnftbnftactg0001)2cos()(2)2sin()(2)(21)2cos()2si

3、n(21)( 是是直直流流分分量量。是是基基波波頻頻率率，其其中中：數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎21數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎22數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎23數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎24基帶傳輸和頻帶傳輸基帶傳輸和頻帶傳輸 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎25數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎26數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎27數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎28(Differential Manchester Encoding)(Manchester Encoding)數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎29數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎30數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)

4、通信基礎31后的幅值。每個樣值的二進制碼組稱為后的幅值。每個樣值的二進制碼組稱為碼字碼字，其位數(shù)稱為其位數(shù)稱為字長字長。字長字長= =loglog2 2n n數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎32 2 4 6 810121416D7=1.31D6=9.29D5=15.215D4=10.811D3=5.66D2=2.83D1=2.7312Bt數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎33數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎345101501 0 1 1 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1樣本間隔時間被發(fā)送的位串數(shù)字化線連續(xù)的樣本總是相差1信號變化太快，以至編碼不能表示信號的變化數(shù)據(jù)通信與

5、計算機網(wǎng)絡數(shù)據(jù)通信基礎35數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎36 001)ft2cos(A)t(S當當數(shù)數(shù)字字信信號號為為當當數(shù)數(shù)字字信信號號為為 二元調(diào)幅二元調(diào)幅脈沖編碼脈沖編碼數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎37 0)tf2cos(A1)tf2cos(A)t (S21當當數(shù)數(shù)字字信信號號為為當當數(shù)數(shù)字字信信號號為為 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎38數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎39 0)ft2cos(A1)ft2cos(A)t(S當當數(shù)數(shù)字字信信號號為為當當數(shù)數(shù)字字信信號號為為 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎40數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎41三種類型的調(diào)制三種類型的調(diào)制數(shù)據(jù)通信

6、與計算機網(wǎng)絡數(shù)據(jù)通信基礎42數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎43數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎44數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎45數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎46數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎47數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎48數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎49數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎50源系統(tǒng)傳輸系統(tǒng)目的系統(tǒng)傳輸系統(tǒng)源點終點發(fā)送器接收器輸入信息輸出信息輸入數(shù)據(jù)輸出數(shù)據(jù)發(fā)送的信號接收的信號數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎51數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎52數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎53數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎54數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎55數(shù)

7、據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎56數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎57數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎58數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎59數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎60數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎61數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎62同步字符數(shù)據(jù)1數(shù)據(jù)2數(shù)據(jù)n校驗字符CRC1校驗字符CRC2同步字符一幀下一幀數(shù)據(jù)場同步字符數(shù)據(jù)1數(shù)據(jù)2數(shù)據(jù)n校驗字符CRC1校驗字符CRC2同步字符一幀下一幀同步字符數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎63 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎64頻率頻率時間時間頻率頻率 1頻率頻率 2頻率頻率 3頻率頻率 4頻率頻率 5數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎6

8、5 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎66 1Channel 330031001Channel 21Channel 16064687260646872Channel 1Channel 3Channel 2頻率(KHz)(c)頻率(KHz)(b)頻率(Hz)(a)300 3400數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎67數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎68 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎69 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎70數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎71124.n13.n.1234.n時間片1時間片2時間片n125.m41257.m.1234.m時間片1時間片2時間片n數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)

9、據(jù)通信基礎72信道 24信道 1信道2信道3信道401193比特幀(125微秒）幀開始位7位數(shù)據(jù)位校驗位數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎73數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎74數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎75 共享光纖光柵光柵功率波長共享光纖的波譜功率波長光纖1的波譜功率波長光纖2的波譜光纖1光纖2光纖3光纖4功率波長光纖3的波譜功率波長光纖4的波譜數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎76數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎77 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎78 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎79數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎80 011miiiTSmTSmimiimiiimSmSSm11

10、2211)1(111SS數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎81數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎82數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎83數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎84數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎85數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎86(A(BCD數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎87數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎88數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎89數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎90數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎91數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎92數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎93 由于分組長度較短，在傳輸出錯時，檢錯容易并且重由于分組長度較短，在傳輸出錯時，檢錯容易并且重發(fā)

11、花費的時間較少；發(fā)花費的時間較少； 限定分組最大數(shù)據(jù)長度，有利于提高存儲轉(zhuǎn)發(fā)結點的限定分組最大數(shù)據(jù)長度，有利于提高存儲轉(zhuǎn)發(fā)結點的存儲空間利用率與傳輸效率；存儲空間利用率與傳輸效率； 公用數(shù)據(jù)網(wǎng)采用的是分組交換技術。公用數(shù)據(jù)網(wǎng)采用的是分組交換技術。報文分組：報文分組：報文：報文：報文號目的地址源地址校驗報文號目的地址源地址報文分組數(shù)據(jù)校驗報文分組號數(shù)據(jù)數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎94數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎95數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎96數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎97數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎98P1P3P4報文報文報文 報文P2P1P3P4P2P1P3P4P2P

12、1P3P4P2P1P3P4P2P1P3P4P2t 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎99數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎100數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎101數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎102數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎103數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎104數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎105數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎106數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎107數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎108 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎109 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎110數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎111數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎112數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎113數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎114數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎115 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎116 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎117 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎118垂直奇偶校驗（垂直奇偶校驗（VRCVRC） 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎119 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎120 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎121 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎122 數(shù)據(jù)通信與計算機網(wǎng)絡數(shù)據(jù)通信基礎