希尔伯特变换在信号解调中的应用

:2002-04-01:(1977-),,,,,(,450002):,,,:;;:TN911:A:1671-0673(2002)04-0029-031,,,AMFMSSBCW,,ASKFSKMSKGMSKPSKDPSKQPSKQAM,,,,,,,s(t)=A(t)cos[(t)t+(t)]+n(t)(1),A(t)(t)(t),,A(t)(t)(t),s(t)=A(t)cos[ct+(t)](2)A(t)(t),:s(t)=A(t)cos[(t)]cos(ct)-A(t)sin[(t)]sin(ct)=Xi(t)cos(ct)-Xq(t)sin(ct)(3),Xi(t)=A(t)cos[(t)],Xq(t)=A(t)sin[(t)],,Xi(t)Xq(t),Xi(t)Xq(t)A(t)(t):A(t)=X2i(t)+X2q(t),(4)(t)=arctanX2q(t)X2i(t)(5)111,,,,,,,,2:x(t),34Vol.3No.4200212JournalofInformationEngineeringUniversityDec.2002©1995-2006TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.^x(t),H[x(t)]=^x(t)=1+-x+)t-dH-1[^x(t)]=x(t)=-1+-x()t-d:a(t)A(),,c/2,H[a(t)cos(ct)]=a(t)sin(ct)H[a(t)sin(ct)]=-a(t)cos(ct),s(t)=A(t)cos[ct+(t)],c/2,^s(t)=A(t)sin[ct+(t)](6)(2)(6)A(t)=s2(t)+^s2(t),(7)(t)=arctans(^t)s(t)-ct(8)(7)(8)(4)(5),,22A/D,s(t)s(n),s(n)=A(n)cos[nc+(n)](9),x(t)x(t)h(t)=1t,,h(n)=1(n-M/2)[1-(-1)n-M/2]w(n-M/2)(10)w(n),Ms(n)M/2,,s(n)^s(n),A(n)(n)3,,,,DSP,,,,,,,,,IQ,BPSKQPSKIQ,IQ,,,,,,,,,:S(t)=A(t)cos(ct+(t)),N(t)=Q(t)cosct,R(t)=A(t)cos(ct+(t))+Q(t)cosct,(11)^R(t)=A(t)sin(ct+(t))+Q(t)sinct(12):…A(t)=R2(t)+^R2(t)=A2(t)+Q2(t)+2A(t)Q(t)cos(t)(13)(13),A(t)Q(t),…A(t)A(t)+Q(t)(14)A(t)Q(t),,032002©1995-2006TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.4,,,,,,,,,:[1],,1[M].:,20011[2]1(4)[M].:,19951[3]1[M].:,19971HilbertTransformfortheApplicationofSignalDemodulationLIJing2jing,JIANGHua,WANGMing2kun(InstituteofInformationEngineering,InformationEngineeringUniversityZhengzhou450002,China)Abstract:Inthispaper,athoughtofcross2demodulationforthepresentsoftwareradioisintroduced.AnewarchitectureofgeneraldemodulatorbasedontheHilbertTransformisprovided.Thenewarchitectureiscomparedwiththecross2demodulatorandfinallythekeytoimprovethedemodulatorisgiven.Keywords:Hilberttransform;softwareradio;demodulation134:©1995-2006TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.