《通信原理教程》(第3版) 樊昌信 编著第六章PPT课件

1、1)cos()(0tAts)2cos()(0tfAtsTTT“1”“1”“0”“1”“1”“0”T2ttetjsincos3TtttAts0)cos()()(0”时。当发送“”时当发送“00,1)(AtA相乘器cos0ts(t)A(t)cos0ts(t)A(t)4包络检波器包络检波器全波全波整流整流带通带通滤波滤波低通低通滤波滤波抽样抽样判决判决定时脉冲定时脉冲s(t)A(t)相干载相干载波波cos 0t相乘相乘电路电路带通带通滤波滤波低通低通滤波滤波抽样抽样判决判决定时脉冲定时脉冲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) 功率谱密度功率谱密度PA(f)的曲线的曲线(b) 功率谱密度功率谱密度Ps(f)的曲线的曲线9Tttntsty0)()()(”时。当发送“”时，当发送“001cos)(0tAtsttnttntnsc00sin)(cos)()(”时发送“”时发送“0sin)(cos)(1sin)(cos)(cos)(00000ttnt

4、tnttnttntAtyscsc”时发送“”时发送“0sin)(cos)(1sin)(cos)()(0000ttnttnttnttnAtyscsc10 ”时当发送“”时当发送“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”时发送“”时发送“0)()(1)()()(2222tntntntnAtVscsc4/21reeP13WBnn8021092. 11261092. 121028622nAr45 .64105 .72121eePre45 . 641066. 1261416. 311eerPre14”时当发送“”时当发送“0)cos(1)cos()(0011tAtAtsA(t)开关电路开关电路频率源频率源1频率源频率源0s(t)f1f0调频器调频器A(t)s(t)15定时脉冲定时脉冲低通滤波低通滤波低通滤波低通滤波抽样判决抽样判决输出输出带通滤波带通滤波f0带通滤波带通滤波f1输入输入相乘相乘相乘相乘

6、cos 0tcos 1tV0(t)V1(t)y1(t)y0(t)带通滤波带通滤波f0带通滤波带通滤波f1包络检波包络检波包络检波包络检波抽样判决抽样判决定时脉冲定时脉冲输入输入输出输出V0(t)V1(t)16带通滤波带通滤波放大限幅放大限幅低通低通微分微分整流整流脉冲展宽脉冲展宽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”时当发送“”时当发送“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”时当发送“”时当发送“0)(cos1)(cos)(01tntAtntAty定时脉冲定时脉冲低通滤波低通滤波低通滤波低通滤波抽样判决抽样判决输出输出带通滤波带通滤波f0带通滤波带通滤波f1输入输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带通滤波带通滤波f0带通滤波带通滤波f1包络检波包

11、络检波包络检波包络检波抽样判决抽样判决定时脉冲定时脉冲输入输入输出输出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”时当发送“”时当发送“100”时当发送“”时当发送“1)cos(0)cos()(00tAtAts”时当发送“”时当发送“1cos0cos)(00tAtAts30“1”“1”“0”A图图6.4.1 2PSK信号码元序列信号码元序列“101”的波形的波形3132本地载波本地载波提取提取带通滤波带通滤波低通滤波低

13、通滤波相相 乘乘抽样判决抽样判决V(t)33”时当发送“”时当发送“1cos0cos)(00tAtAtstnTtgattAtsnn00cos)(cos)()()1PAPAan概率为（概率为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信号的功率谱密度信号的功率谱密度(b) 2PSK信号的功率谱密度信号的功率谱密度37A2AA(a) 2ASK(c) 载波载波(b) 2PSK38本地载波本地载波提取提取带通滤波带通滤波低通滤波低通滤波相相 乘乘抽样判决抽样判决V(t)”时当发送“”时当发送“1)(0)()(tnAtnAtVcc)0/0(0”时发送“VPPe)1/0(1”时发送“VPPe0A-APe0Pe1V10102/2/ee

15、eeePPPPP02/)(0212122rerfcdxePnAxnererfcPe21reerP2139”时当发送“”时当发送“100Tttts0),cos()(00 0 0 0 0 0 0 0 0 2DPSK码元相位码元相位( + ) 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 基带信号基带信号40 000 / 2- / 2参考相位参考相位参考相位参考相位 (a)A方式方式 (b) B方式方式4142码变换器码变换器（双稳触发器）（双稳触发器）绝对码绝对码相对码相对码A(t)载波载波移相移相 s(t)码变换码变换43s0(

16、t)相相 乘乘带通滤波带通滤波低通滤波低通滤波抽样判决抽样判决V(t)延迟延迟Ts(t)A(t)s1(t)本地载波本地载波提取提取相相 乘乘带通滤波带通滤波低通滤波低通滤波抽样判决抽样判决逆码变换逆码变换44脉冲展宽脉冲展宽逆码变换器逆码变换器微分整流微分整流cbabc 1 1 1 0 0 1 1 0 1（绝对码）（绝对码）a(0) 1 0 1 1 1 0 1 1 0（相对码）（相对码）(a) 原理方框图原理方框图(b) 波形图波形图45s0(t)相相 乘乘带通滤波带通滤波低通滤波低通滤波抽样判决抽样判决V(t)延迟延迟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本地载波本地载波提取提取相相 乘乘带通滤波带通滤波低通滤波低通滤波抽样判决抽样判决逆码变换逆码变换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误码率公式误码率公式键控方式键控方式56222/nAr20/Er bbrkrkEE202057(a) 基带多电平单极性不归零信号基带多电平单极性不归零信号(b) MASK信号信号0010110101011110000t0t0101101010111100000101101010111100000t00000t01011010101111(c) 基带多电平双极性不归零信号基带多电平

21、双极性不归零信号(d) 抑制载波抑制载波MASK信号信号580t0101101010111100000t01011010101111000001010t10101011110000001t1010101111000059110-110-210-310-410-510-6Per (dB)2/121311rMerfcMPererfcPe2160TTTTf3f1f2f461V1(t)带通滤波带通滤波f1抽样抽样判决判决包络检波包络检波带通滤波带通滤波fM包络检波包络检波定时脉冲定时脉冲输入输入输出输出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 序号序号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 参考相位参考相位00101101参考相位参考相位 (a) A方式方式 (b)B方式方式 70cos ( 0t+ /2) = -sin 0t载波载波产生产生相乘相乘电路电路相乘相乘电路电路 /2移相移相串串/并并变换变换相加相加电路电路cos 0tA(t)s(t)图图6.7.8 第一种第一种QPSK信号产生方法信号产生方法ab01110010a(1)a(0)b(1)b(0)B方式编码方式编码 71串串/并并变

25、换变换串串/并并变换变换带通带通滤波滤波串串/并并变换变换 1 4 3 2ab72载波载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定时定时提取提取730111001090 0 2/0)(1dfPe22/2111rerfcPe74)/(sin2MreePPerb （dB）75abkA方式方式000 1090 11180 01270 76abcd码码变换变换相加相加电路电路s(t)A(t)串串/并并变换变换- /4载波载波产生产生相乘相乘电路电路相乘相乘电路电路 /4A方式编码方式编码77当前输入的一对码元及当前输入的一

26、对码元及要求的相对相移要求的相对相移前一时刻经过码变换后的前一时刻经过码变换后的一对码元及所产生的相位一对码元及所产生的相位当前时刻应当给出的当前时刻应当给出的变换后一对码元和相位变换后一对码元和相位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码变换关系码变换关系: 78图图6.7.15 A方式方式QDPSK信号解调方法信号解调方法bacdA(t)- /4相乘相乘电路电路相乘相乘电路电路 /4s(t)低通低通滤波滤波低通低通滤波滤波抽样抽样判决判决抽样抽样判决判决并并/串串变换变换逆码逆码变换变换定时定时提取提取载波载波提取提取79)cos()(0kkttsTktkT) 1( )4cos(0t)4cos(0t)4cos(21)4(2cos21)