卫星通信第4章信号传输

SignalTransmissionnnnn(ARQ)n4.1nnn4.1n300-3400Hz()(8000/s)A/D8bit/64kbits/s4.1.1nMOS4.1.1nn16kb/s,32kb/s,64kb/s2.4—13kb/s4.1.24.1.2nPCM,64kb/s,4.3nADPCM(~),32kb/s,4.1nLPC(),2.4kb/s,2.5CELP(~)VSELP(~)nIMBE(),6.5kb/s,3.44.24.2.1n()cos(())cos()cossin()sincccstAttAttAtt=+Φ=Φ-Φggcos()tIΦ=sin()tQΦ=BPSKn0180nTs=Tbnnfn2sin()()sssfTLfTfTpp⎛⎞=⎜⎟⎝⎠()()coscrtattw=21()cos()(1cos2)2ccattattww=⋅+QPSKn2bitnTs=2TbEs=2EbnnQPSKQPSKBPSK22sin()sin(2)()2sbsbsbfTfTLfTTfTfTpppp⎛⎞⎛⎞==⎜⎟⎜⎟⎝⎠⎝⎠O-QPSKp/4-QPSK10001101CPFSKMSKGMSKMSKnCPFSK—nCPFSK—nMSKCPFSKnGMSKMSK4.2.2nnnNyquistNyquistnNyquistnb12111222212for0||()()()(){1cos[(||)]}for||0for||sssssssTTTTTTTTfHfPfGfRffffbbbbpbb+--++⎧≤≤⎪⎪==+-⎨⎪≥⎪⎩2(1)1logbsRTMBbb++==nRb=1/TbMn2M=2M=4n22log1/logsbbTTMRM==2logsbEEM=2logbitrateb/sbandwidth1HzinMbbh+==4.2.3nBPSKnQPSKnMSKFSKnDPSKnFSK110022//bbsperfcENerfcEN==22()txerfcxedtp∞=∫110022//2bbsperfcENerfcEN==102/bbperfcEN=0122exp()bEbNp-=102exp(/2)bbpEN=-4.2.34.2.4/nnnnnnBPSKna0nBPSKQPSKDPSK,FSK()()()atxtytm=++2{|()|}1Eat=222cms=21ccm=+21/21cs=+2102()/bspaerfcaEN=0()()bbappafada∞=∫BPSKQPSK4.3nnnFECnnnnnn4.3.1TrellisnViterbi:Viterbi(Trellis)nHammingTrellis2dBnViterbinnnBPSKjn102/jsPerfcjEN=1bjjkjdpPw∞=∑1/24.3.2nnCkInn()()()CxIxGx=min2ted+4.3.3CRCnCRCn10-416bitCRCn()2nkup--=4.3.4RSnBCHBCHHammingnRSnmbitn2t+e=n-kRStenl(n-l,k-l)l04.3.5nnpbnn4.3.5nnn4.4,ARQnFECARQFECARQnStop-and-WaitARQ,Go-Back-NARQ,Selective-RepeatARQ,HybridARQ4.4.1Stop-and-waitARQn4.4.2Go-Back-NARQnn4.4.3Selective-RepeatARQnnnInmarset-C4.5TurbonTurbo1993C.BerrounnnshannonTurboRSC1RSC2sXpX2pX1pX1uTurboDEC1L(un)ypdemuxysy1py2p+w(ys)DEC2eL21~Le21Le12)~(21eLwkuˆTurbonnTurbonnn3G4GOFDMSpace-timeThankyou!