PCM TDM 5. Q 28726?2?
AM VsSinωst t ωs ω VcSinωct t ωc ω t ωc-ωs ωc+ωs Vc(1+mSinωst)Sinωct ωc ω SinωsSinωc=-1/2Cos(ωs+ωc)+1/2Cos(ωs-ωc) " " " " AM(DSB,SSB)/FM/PM FDM" 1R" " " " 2PCM" " TDM" R" " "
" Pulse Code Modulation: PCM " " 2" PCM" " " PCM PCM() 001 010 100 100 010 001 (PAM) (PCM)
Step1: PAM ωmωs/ ωm ωs Step2: PAM (PAM) t t
p N Q y i = y i + y i +1 : (s = y 2 i+1 y i ) iyii n y N Q = p i {y (y i + s i + s y i =1 2 )}2 dy = i p s3 i i =1 12 = s2 12 V 2 s = V N Q = 12 2 2 n 2n NqdB n s s s p111 [bps] [Hz] [bit]
AD" n n n bita n,a n-1,+a 2,a 1 " inpamn inv 0 (a n 2 n-1 +a n-1 2 n-2 ++a 2 2 1 +a 1 +ε) in V 0 2 n-1 V 0 " in >V 0 2 n-1 a n 1,< in V 0 (a n 2 n-1 +2 n-2 a n-1 1,<" n a n,a n-1,+a 2,a 1 nor0 ADPAM f02f0 τ Vin t PCM PAM AD
Step3: 2" bit " 2! bit
PCM 2 23 S5 S4 S3 S2 S1 100 110 101 011 010 2 b3,b2,b1 b3b2b1 7 6 5 111 110 101 4 100 3 011 2 1 010 001 0 000 S5 S4 S3 S2 S1
LSI PCM LSI 3R CRC
PCM WAV PCM bit- rate khz khz 1/2f0=1/6.8kHz khz bit kbit/s Full Speck (CCITT 3.1kHz 64kbit/s
2kHzCD khz-16bit" CD20kHz" 1/2f0=1/40kHz44.1kHz" 6553616bit" 2ch 1.4112 Mbit/s" MD:1624bit" ADPCM(PCM)" 292kbit/s" PCM/ <khz PAM 256 =2 8 8bit Sampling Pules >8kHz PCM2 2 2 2 164[kbit] 8[bit] 8 [khz] =64 [k bit /s] 176.8[kbit]
kbps ( " " "
NTSC(Na$onal Television System Commi2ee) " 2012"
VHF(30-300MHz,FM1-12ch)" UHF(300M-3GHz,13-62ch)" UHF" +EU8 6MHz(470-770MHz13-62ch)" " " " 121" " 4 7 PCM JPEG(,MPEG
(1) RGBYCbCr (2) DCT (3) " "
MPEG(Moving Picture Experts Group)}" MPEG1 NTSC352 240Mbit/s" MPEG2 720 4801920 1152 NTSCMbit/sHDTVMbit/s" " (MPEG1or4 Layer3:" MPEG2
16bit44.1kHz 16sampling 2Byte 161=(16*16+16)=272bit 144.1k/16==2756.25, 1749700bit 12,698,920,000bit=337.365MByte 337.365kByte 674.7MByte 10.1kHz~10kHz-70dB -2V~2V 23 S1 S2 S3 S4 S5 b1b2b3 011111101110 010 223 S1 S2 S3 S4 S5 b1b2b3 001011 101 001 010
2 2 3 28-29+α C(bit/s)=W(Hz)log2(1+S/N) C S WN S/N " "
P 1 0 1 0 0 0 b7 1 1 0 1 1 0 b6 0 0 0 1 0 1 b5 0 1 1 0 0 0 b4 0 0 0 1 0 0 b3 0 1 0 1 1 1 b2 0 0 0 0 0 0 b1 1 0 1 0 1 1 a b c d f BCC 1 0 1 1 1 0 b 1 b4 1 db410 2
CRC Mr CRC (b8b7bb6b5b4b3b2b1)(10010101) module2 (b8b7bb6b5b4b3b2b1)(10110000) 8CRC 0 10010101. 1100000 0 0 10110000 0 08bit (7bit MRCRC r=r-1
bit CRC(Cyclic Redundancy Check cord) CRC= (17bit) F(x) 0 OK0: PCM (0)