2019通信中级传输与接入(无线)宝典

1、1.11.1.21.1()fv:c:1.1.3XX1.1.4:100000m 0.75mm2018. .VLF3Hz 30KHz10Km100Km1Km 10KmLF300KHz300KHz MF0.1Km1KmAMHz533KHz1065KHz3MHz HF10m 100m30MHz60MHz30MHz300MHz1m 10m30MHz144MHzFMVIIF88MHz 108MHz300MHz 0.1m 352MHz 420MHz700MHz 10GHz1.7GHzUHF2.4GHz3GHz SHF30GHz1cm 10cm1mm 10mm3.6GHz 4.2GHz1.5GHz 1.6GH

2、zEHF300GHz1.21.2.12018. .1:1.2.21.2.3dB 2018. 6dB2018. .1r(t) = A(t)s(t) + n(t)A(t)(Rayleigh) (Ricean)A(t)BcBsISI2018. .Bc BsBc Bsax,Bc1.2.420m15kmhga3km()4m:1m 4m3dB2018. .3()()()2018. .220dB1.2.5(1)()()d(2)(3)(4)20dB 40dB(50%)UHF6dB 12dB11d2018. .v2018. .:a.b.c.d.1.31.3.12018. .4(a)(b)()()()Acknow

3、leged Mode, 2018 . Amplitude Shift KeyingASK)Frequency Modulation, FM) Phase Modulation,PM)Frequency Shift KeyingPhase Shift KeyingPSK)1.3.21.4.1(1.4.1()()()1.41.4.22018. .()()()2018. .()(-3dB)()()dBi;2018. .2dBd2018. .5075:3:2018. .110dB 20dB2018. .Voltage Standing Wave Ratio, VSWR):12018. .31.51.4

4、.3(z)zZ( z)zZ 3:()1.51.5.1()1.5.2()Un;()()()2018. .3()= -issc2(sin= -icsiQs2.12.1.12.1ASK:FSK: PSK:2.1.2445o135o225o315oQPS400 01 10 444QPSK4( 2PSKQPSK)2.2.12.22.2.1(QAM)MQAMDQPSKM2018. .1DQPSK()(Frequency Division Duplexing (Time Division DuplexingTDD)2018. .1FDDTDD(FDD)FDD500km/h TDDTDD120km/h()FDDFDD()TDD4(TDD)FDDTDD2.2.2(Frequency Division Multiple Access, FDMA) TDMA)(Code Division Multiple Access, (TimeDivisionMultipleAccessFDMATDMACDMAFDM