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3.1a.b.a.b.3.2330m/s8fv=λCDEFGABC264297330252396440495528(m)1.251.111110.93750.83330.750.66670.6253.33.14)2sin(ϕπ+ftAϕfA)2sin(πϕ===22fAtttttxϕπ+ftA3.143.33.4100Hz200Hzππππ400sin12400cos5200sin20200cos1512)(−−++=/)]512(tan400cos[13)]34(tan200cos[251251511−+−−++=−−ttππtt100cos)5cos1.01(+)]12(tan400cos[125)]20(tan200cos[201512)(122122−++−−+++=−−tttxππ3.5295201210520121001)295sin(201)2105sin(201)2100sin(95cos20105cos20100cos333222111πϕωπϕωπϕωπππ=========+++++=++=AAAtttttt2)cos10()(ttf=111)]5100cos()5100[cos(201100cos5cos100cos1.0100cos−+++=+tttttttt3.6cosππ)(2cos2cos50502cos100)cos10()(2tftttttf∴+===Qβαβαβα)12(cos21)0cos2(cos21coscoscos)]cos()[cos(21cos)2cos1(2cos22ttttttt+=+==−++=+=3.73.421s1(t)3s2(t)s1(t)fs2(t)5f315f525f5fs2(t)5f7f9f7f5f1.49f5f1.83.83.5(b)13.5(b)90%f=1/XXXf=1/Xf(t)f(t)P=0.5P3BP.81103dBS(f)=0.5Xf22dBPP32lg10lg==12lg10PPNdB=V2V1V21212lg20lg10VVPPNdB==3.9IRA71282070TTS6TTS100TTS(TeleTypeSetterCode)ITU-TITA(INTERNATIONALTELEGRAPHALPHABET)ITA2ITA3ITA55TTS6TTS7TTS7TTSTTSIRAASCII1286TTS6TTS6462621243.105MHzCCIR-MNTSCNTSC152.5us1878.3(a)P/P/252.5/(P/2)=105/PυsfH=P/105MHzfL=0B=P/105MHzB=5MHz5=P/105P=5x105=525CCIR-M/NTSC450B=P/105=450/105=4.3MHz(4.2Hz)4.2MHz5MHz7516.7%2fH=5MHz1/fH=0.2υs2225/0.2υs×225=45υs11υs56υs56x10-6sV3030V30V×56x10-6=1sV=595/NSTL5257013.3%3.11a.480x5003230R(bps)b.4.5MHz35dB(bps)c.(a)Ra.30480x500(30/)×(480×500/)=7.2×106325R=7.2×106/×5/=36Mbpsb.B=4.5x106MHzSNRdB=35dBSNR=1035/10=103.5,CS=Blog2(1+SNR)=4.5×106log2(1+103.5)=4.5×106×log2(3163)=(4.5×106x11.63)=52.335×106bpsc.a532333=2751111111111112223331231231230000000001000100001100100001010011000111010002222222221112223331231231230100101010010110110001101011100111110000100013333333331112223331231231231001010011101001010110110101111100011001110105325323276835123.1210000K10MHzN=-228.6dBW+10log104+10log107=-228.6+40+70=-118.6dBW3.13*300Hz3dBB=300HzSNRdB=3dBSNR=103/10=100.3CS=Blog2(1+SNR)=300×log2(1+100.3)=300×log23=300×1.58=474bps3.149600bpsa.4b.8a.4log2M=4R=9600bpsCN=2Blog2M=9600bpsB=9600/2×4=1200Hzb.log2M=8B=9600/2×8=600Hz3.15*10KHz1000W50CdB1HzN0=kT=(1.3803×10-23)×(273+50)=4.46×10-21W/Hz10kHzN=N0×10×103=4.46×10-17WSNRdB=10lg(S/N)=10lg(1000/(4.46×10-17)=10lg(2.24×1019)=193.5dB3.16P.73-743.1720Mbps3MHzC=20MbpsB=3MHzCS=Blog2(1+SNR)C=20×1063×106×log2(1+SNR)log2(1+SNR)6.671+SNR26.671+SNR102SNR1013.18.3.7(c)T=1ms8kHza.b.N0=0.1uW/HzdBT=1msf=1000HzN0=0.1uW/Hz=1x10-7W/Hza.3.7(c)8kHz7f7kHzdtkftkTPkT2300|12])12(2sin[4|1++=∑∫=ππk=32k+1=7b.S/NSS=PNN0BSNWB=8kHzN=N0B=(1×10-7W/Hz)×(8×103Hz)SNRdB=10log(S/N)=10lgS(dBW)10lgN(dbW)3.19-151dBW1500K2400bpsEb/N0Sdbw=-151dBT=1500ºKR=2400bpsEb/N0=Sdbw-10lgR+228.6dbW-10lgT=-151-10lg2400+228.6-10lg1500=-151-33.8+228.6-31.8=12dB3.20.y10lgx=y(dB)xyy123456789100.80.630.50.40.3160.250.20.160.1250.11.251.622.53.16456.38103.2130dB10005.1lg30lg20===xxdBx3.2220WdBW10lg20=13dBW