《通信原理教程》(第3版) 樊昌信 編著第六章PPT課件

1、1)cos()(0tAts)2cos()(0tfAtsTTT“1”“1”“0”“1”“1”“0”T2ttetjsincos3TtttAts0)cos()()(0”時。當(dāng)發(fā)送“”時當(dāng)發(fā)送“00,1)(AtA相乘器cos0ts(t)A(t)cos0ts(t)A(t)4包絡(luò)檢波器包絡(luò)檢波器全波全波整流整流帶通帶通濾波濾波低通低通濾波濾波抽樣抽樣判決判決定時脈沖定時脈沖s(t)A(t)相干載相干載波波cos 0t相乘相乘電路電路帶通帶通濾波濾波低通低通濾波濾波抽樣抽樣判決判決定時脈沖定時脈沖s(t)A(t)5tnTtgattAtsnn00cos)(cos)()()()(41)(00ffPffPfPAA

2、s6mcccccAmffmfGPmfPGffGfGPPffP)()()1 ()()()()1 ()(221221nccccAnffnfGPffGPPffP)()()1 ()()1 ()(2222)()0()1 ()()1 ()(2222fGPffGPPffPccA)()() 0 ()1 (41| )(| )(| )1 (41)(002222020ffffGPfffGffGPPffPccs7)()() 0 ()1 (41| )(| )(| )1 (41)(002222020ffffGPfffGffGPPffPccs)()()0(161)()(161)(00222020ffffGfffGffGff

3、PccsfTfTTfGsin)(TG | )0(|TffTffTffG)()(sin| )(|000TffTffTffG)()(sin)(000)()(161)()(sin)()(sin16)(00200200ffffTffTffTffTffTfPs8f / fcPA(f)(a) 功率譜密度功率譜密度PA(f)的曲線的曲線(b) 功率譜密度功率譜密度Ps(f)的曲線的曲線9Tttntsty0)()()(”時。當(dāng)發(fā)送“”時，當(dāng)發(fā)送“001cos)(0tAtsttnttntnsc00sin)(cos)()(”時發(fā)送“”時發(fā)送“0sin)(cos)(1sin)(cos)(cos)(00000ttnt

4、tnttnttntAtyscsc”時發(fā)送“”時發(fā)送“0sin)(cos)(1sin)(cos)()(0000ttnttnttnttnAtyscsc10 ”時當(dāng)發(fā)送“”時當(dāng)發(fā)送“0)(1)()(tntnAtxcc2212/)(exp21)(nnAxxp2202/exp21)(nnxxph*Pe0p0(x)p1(x)Pe1hA11h*Pe0p0(x)p1(x)Pe1hAhneAherfdxxpP21121211)(duexerfxu022)(hneherfdxxpP2002121)(nneeeherfaherfPPP21412141212101*)(*)(01xpxp2/21rerfcPe4/1r

5、eerP12”時發(fā)送“”時發(fā)送“0)()(1)()()(2222tntntntnAtVscsc4/21reeP13WBnn8021092. 11261092. 121028622nAr45 .64105 .72121eePre45 . 641066. 1261416. 311eerPre14”時當(dāng)發(fā)送“”時當(dāng)發(fā)送“0)cos(1)cos()(0011tAtAtsA(t)開關(guān)電路開關(guān)電路頻率源頻率源1頻率源頻率源0s(t)f1f0調(diào)頻器調(diào)頻器A(t)s(t)15定時脈沖定時脈沖低通濾波低通濾波低通濾波低通濾波抽樣判決抽樣判決輸出輸出帶通濾波帶通濾波f0帶通濾波帶通濾波f1輸入輸入相乘相乘相乘相乘

6、cos 0tcos 1tV0(t)V1(t)y1(t)y0(t)帶通濾波帶通濾波f0帶通濾波帶通濾波f1包絡(luò)檢波包絡(luò)檢波包絡(luò)檢波包絡(luò)檢波抽樣判決抽樣判決定時脈沖定時脈沖輸入輸入輸出輸出V0(t)V1(t)16帶通濾波帶通濾波放大限幅放大限幅低通低通微分微分整流整流脈沖展寬脈沖展寬abcedf17ttAttAts0011cos)(cos)()(nnatA)(1nnatA)(01nnaa)()(41)(00ffPffPfPAAs)()(41)()(41)(00001111ffPffPffPffPfPAAAAs)()0()1 ()()1 ()(2222fGPffGPPffPccA18)()()0(4

7、1)()()0()1 (41)()()1 (41)()()1 (41)(002221122220202121ffffGPfffffGPfffGffGPPfffGffGPPffPccccs)()()()()0(161)()()()(161)(00112220202121fffffffffGfffGffGffGffGffPccsfTfTTfGsin)(TG)0()()()()(161)()(sin)()(sin)()(sin)()(sin161)(0011200200211211ffffffffTffTffTffTffTffTffTffTfffPs19)()()()(161)()(sin)()(s

8、in)()(sin)()(sin161)(0011200200211211ffffffffTffTffTffTffTffTffTffTfffPsfsfs = (f0 +f1) / 2ff1 + fcf0 - fcf0f12fcf1fsff0fs = (f0 +f1) / 2fcf1 + fcf0 - fcfs = (f0 +f1) / 2f1 + fcf0 - fccffff20120”時當(dāng)發(fā)送“”時當(dāng)發(fā)送“0)cos(1)cos()(0011tAtAtsTdttt000110)cos()cos(Tdttt0010101010)cos()cos(210)()sin()()sin()sin()s

9、in(01010101010101010101TT0 1)cos(sin()sin()cos(01010101TT210 1)cos(sin()sin()cos(01010101TT0)sin(01T1)cos(01TnT )(01mT2)(01mT2)(01Tmff/010010)sin(01T0 1)cos(sin()sin()cos(01010101TTTnff2/0122”時當(dāng)發(fā)送“”時當(dāng)發(fā)送“0)(cos1)(cos)(01tntAtntAty定時脈沖定時脈沖低通濾波低通濾波低通濾波低通濾波抽樣判決抽樣判決輸出輸出帶通濾波帶通濾波f0帶通濾波帶通濾波f1輸入輸入相乘相乘相乘相乘cos

10、 0tcos 1tV0(t)V1(t)y1(t)y0(t)ttnttnAtysc11111sin)(cos)()(ttnttntysc00000sin)(cos)()()()(11tnAtVc)()(00tntVc23)()(11tnAtVc)()(00tntVc)0()()(0101011ccccennAPnnAPVVPP2201222nccznnzz002/)(122121)()0(22rerfcdzedzzfzPPzAzze222/nAr221rerfcPe24)()()(21211tntnAtVsc)()()(20200tntntVsc帶通濾波帶通濾波f0帶通濾波帶通濾波f1包絡(luò)檢波包

11、絡(luò)檢波包絡(luò)檢波包絡(luò)檢波抽樣判決抽樣判決定時脈沖定時脈沖輸入輸入輸出輸出V0(t)V1(t)1222102102110000110112/2exp)()()(10dVAVAVIVdVdVVfVfVVPPnnnVVe25nnAzVt2,211222102102110000110112/2exp)()()(10dVAVAVIVdVdVVfVfVVPPnnnVVe02/ )(02/1222)(21dtezttIePztze02/ )(01)()0 ,(22dtezttIzQzt2/2/121212rzeeeP2222/nAzr2/21reeP264/21reeP2/21reeP2/21rerfcPe2

12、21rerfcPe27120030029801580201cffff482/107 . 12121eePre285105 .399993.01218284.212181212121221erferfrerfrerfcPe582/1039.332121eerPre29)cos()(0tAts”時當(dāng)發(fā)送“”時當(dāng)發(fā)送“100”時當(dāng)發(fā)送“”時當(dāng)發(fā)送“1)cos(0)cos()(00tAtAts”時當(dāng)發(fā)送“”時當(dāng)發(fā)送“1cos0cos)(00tAtAts30“1”“1”“0”A圖圖6.4.1 2PSK信號碼元序列信號碼元序列“101”的波形的波形3132本地載波本地載波提取提取帶通濾波帶通濾波低通濾波低

13、通濾波相相 乘乘抽樣判決抽樣判決V(t)33”時當(dāng)發(fā)送“”時當(dāng)發(fā)送“1cos0cos)(00tAtAtstnTtgattAtsnn00cos)(cos)()()1PAPAan概率為（概率為34)()(41)(00ffPffPfPAAsmcccccAmffmfGPmfPGffGfGPPffP)()()1 ()()()()1 ()(221221)()0()1 ()0()()1 (4)(22121fGPPGffGPPffPccA21)()(fGffPcA201201| )(| )(|41)(ffGffGffPcs35fTfTTfGsin)(200200)()(sin)()(sin4)(TffTffT

14、ffTffTfPs201201| )(| )(|41)(ffGffGffPcs)()(161)()(sin)()(sin16)(00200200ffffTffTffTffTffTfPs36(a) 2ASK信號的功率譜密度信號的功率譜密度(b) 2PSK信號的功率譜密度信號的功率譜密度37A2AA(a) 2ASK(c) 載波載波(b) 2PSK38本地載波本地載波提取提取帶通濾波帶通濾波低通濾波低通濾波相相 乘乘抽樣判決抽樣判決V(t)”時當(dāng)發(fā)送“”時當(dāng)發(fā)送“1)(0)()(tnAtnAtVcc)0/0(0”時發(fā)送“VPPe)1/0(1”時發(fā)送“VPPe0A-APe0Pe1V10102/2/ee

15、eeePPPPP02/)(0212122rerfcdxePnAxnererfcPe21reerP2139”時當(dāng)發(fā)送“”時當(dāng)發(fā)送“100Tttts0),cos()(00 0 0 0 0 0 0 0 0 2DPSK碼元相位碼元相位( + ) 0初始相位初始相位 0 0 0 0 0 0 1 1 1 0 0 1 1 0 11 1 1 0 0 1 1 0 1 基帶信號基帶信號40 000 / 2- / 2參考相位參考相位參考相位參考相位 (a)A方式方式 (b) B方式方式4142碼變換器碼變換器（雙穩(wěn)觸發(fā)器）（雙穩(wěn)觸發(fā)器）絕對碼絕對碼相對碼相對碼A(t)載波載波移相移相 s(t)碼變換碼變換43s0(

16、t)相相 乘乘帶通濾波帶通濾波低通濾波低通濾波抽樣判決抽樣判決V(t)延遲延遲Ts(t)A(t)s1(t)本地載波本地載波提取提取相相 乘乘帶通濾波帶通濾波低通濾波低通濾波抽樣判決抽樣判決逆碼變換逆碼變換44脈沖展寬脈沖展寬逆碼變換器逆碼變換器微分整流微分整流cbabc 1 1 1 0 0 1 1 0 1（絕對碼）（絕對碼）a(0) 1 0 1 1 1 0 1 1 0（相對碼）（相對碼）(a) 原理方框圖原理方框圖(b) 波形圖波形圖45s0(t)相相 乘乘帶通濾波帶通濾波低通濾波低通濾波抽樣判決抽樣判決V(t)延遲延遲Ts(t)A(t)s1(t)ttnttnAtssc00000sin)(co

17、s)()(ttnttnAtssc01011sin)(cos)()(46)()()()(21)(1010tntntnAtnAtVsscc0)0(10100ssccennnAnAPVPP221221221221212141bbaabbaabbaa022102102102100ssccssccennnnnnnnAPP)(210RRPPe21021012ssccnnnnAR2102102ssccnnnnR4721021012ssccnnnnAR2102102ssccnnnnR22214/42102112)(nARnneARIRRf2224/2222)(nRneRRf)(210RRPPe0014/422

18、1021122102221122)()(dReARIRdRdRRfRfPnARnnRRereeP210222/nAr48reeP211reeP2149本地載波本地載波提取提取相相 乘乘帶通濾波帶通濾波低通濾波低通濾波抽樣判決抽樣判決逆碼變換逆碼變換50 eeePPP)1 (22/ eePP1/ eePP51rerfcrerfcPe211 eeePPP)1 (2rerfcPe212121rerfPererfrerfcPPee1252661202102101012Bnn41021reeP52. 85000ln222nArdBm7 .17107 . 110252. 852. 825622WAPns5

19、34101rerfPe9999. 01014rerf75. 2r56. 7rdBm2 .18101 .1510256. 756. 726622WAPns54-6 -3 0 3 6 9 12 15 18信噪比信噪比r (dB)110-110-210-310-410-510-610-7Pe非相干非相干ASK相干相干ASK非相干非相干FSK相干相干FSK相干相干DPSK非相干非相干DPSKPSK554/21reeP221rerfcPe2/21reeP221rerfcPereeP21)211 (rerfcrerfcPererfcPe21 式式(6.4-13) 相干相干2PSK 式式(6.5-25)相干

20、相干2DPSK 式式(6.5-15)非相干非相干2DPSK 式式(6.3-28)相干相干2FSK 式式(6.3-37)非相干非相干2FSK 式式(6.2-28)相干相干2ASK 式式(6.2-49)非相干非相干2ASK誤碼率公式誤碼率公式鍵控方式鍵控方式56222/nAr20/Er bbrkrkEE202057(a) 基帶多電平單極性不歸零信號基帶多電平單極性不歸零信號(b) MASK信號信號0010110101011110000t0t0101101010111100000101101010111100000t00000t01011010101111(c) 基帶多電平雙極性不歸零信號基帶多電平

21、雙極性不歸零信號(d) 抑制載波抑制載波MASK信號信號580t0101101010111100000t01011010101111000001010t10101011110000001t1010101111000059110-110-210-310-410-510-6Per (dB)2/121311rMerfcMPererfcPe2160TTTTf3f1f2f461V1(t)帶通濾波帶通濾波f1抽樣抽樣判決判決包絡(luò)檢波包絡(luò)檢波帶通濾波帶通濾波fM包絡(luò)檢波包絡(luò)檢波定時脈沖定時脈沖輸入輸入輸出輸出VM(t): : :1)(1 MhP62hhNnnnedNeNhP2222/2/2)(1)(1 1)

22、(MehPhP0,21exp)(222202xAxAxIxxpnnn630)()(dhhPhpPee22)1(2/111111) 1(nnnAMnneennMP224/21nAeeMP64224/21nAeeMP2/2/212120rEeeMeMP)2/exp(21bekrMP2ln2exp)2/exp(bberkkrMPkeMk2ln2 2ln2, 02ln2bbrr即65M80 0 0 01 0 0 12 0 1 03 0 1 14 1 0 05 1 0 16 1 1 07 1 1 1)2/1 (1 21221keekkbPPP2/ebPP 66rb(dB)Pe67dAdueePMrAuA

23、e122/2/2221211)()1(rerfcMPePerb(dB)68)cos()(0kktAtstbtattskkkk000sincos)cos()(kkacoskkbsin69ab kA方式方式B方式方式000 225 1090 315 11180 45 01270 135 序號序號12340 0 0 0 0 0 0 0 0 0 0 0 0 0 0 10 0 1 00 0 1 056780 1 0 10 1 1 10 1 1 00 1 0 00 1 0 0 0 1 0 10 1 1 00 1 1 19101112131415161 1 0 01 1 1 01 1 1 11 1 0 11

24、 0 0 11 0 1 11 0 1 01 0 0 0 1 0 0 01 0 0 11 0 1 01 0 1 11 1 0 01 1 0 11 1 1 01 1 1 10111001045 參考相位參考相位00101101參考相位參考相位 (a) A方式方式 (b)B方式方式 70cos ( 0t+ /2) = -sin 0t載波載波產(chǎn)生產(chǎn)生相乘相乘電路電路相乘相乘電路電路 /2移相移相串串/并并變換變換相加相加電路電路cos 0tA(t)s(t)圖圖6.7.8 第一種第一種QPSK信號產(chǎn)生方法信號產(chǎn)生方法ab01110010a(1)a(0)b(1)b(0)B方式編碼方式編碼 71串串/并并變

25、換變換串串/并并變換變換帶通帶通濾波濾波串串/并并變換變換 1 4 3 2ab72載波載波提取提取相乘相乘低通低通抽判抽判 /2相乘相乘低通低通抽判抽判并并/串串A(t)s(t)abcos 0t-sin 0t定時定時提取提取730111001090 0 2/0)(1dfPe22/2111rerfcPe74)/(sin2MreePPerb （dB）75abkA方式方式000 1090 11180 01270 76abcd碼碼變換變換相加相加電路電路s(t)A(t)串串/并并變換變換- /4載波載波產(chǎn)生產(chǎn)生相乘相乘電路電路相乘相乘電路電路 /4A方式編碼方式編碼77當(dāng)前輸入的一對碼元及當(dāng)前輸入的一

26、對碼元及要求的相對相移要求的相對相移前一時刻經(jīng)過碼變換后的前一時刻經(jīng)過碼變換后的一對碼元及所產(chǎn)生的相位一對碼元及所產(chǎn)生的相位當(dāng)前時刻應(yīng)當(dāng)給出的當(dāng)前時刻應(yīng)當(dāng)給出的變換后一對碼元和相位變換后一對碼元和相位ak bkkck-1 dk-1 k-1ck dk k0 00 0 01 01 10 10 90 180 270 01 01 10 10 90 180 270 1 090 0 01 01 10 10 90 180 270 1 01 10 10 090 180 270 0 1 1180 0 01 01 10 10 90 180 270 1 10 10 01 0180 270 0 90 0 1270 0 01 01 10 10 90 180 270 0 10 01 01 1270 0 90 180 QDPSK碼變換關(guān)系碼變換關(guān)系: 78圖圖6.7.15 A方式方式QDPSK信號解調(diào)方法信號解調(diào)方法bacdA(t)- /4相乘相乘電路電路相乘相乘電路電路 /4s(t)低通低通濾波濾波低通低通濾波濾波抽樣抽樣判決判決抽樣抽樣判決判決并并/串串變換變換逆碼逆碼變換變換定時定時提取提取載波載波提取提取79)cos()(0kkttsTktkT) 1( )4cos(0t)4cos(0t)4cos(21)4(2cos21)