??F???? ??????G?S?? ????

1
??F???? ??????G?S?? ????

• ???????S??S ??F??????S?S

???G????????? ? ??????S??S ? ?O????????S?
2
??F??????S? ?????G???? S?????S
1. ?e??µat?????a
? µetat??p? e??? s??e???? s?µat?? Sc(t) se s?µa
d?a???t?? ?????? Sd(n) Sd(n) Sc(nTs) fs1/Ts
(sampling frequency) 44.100 22.050
11.025
Sample rate (Hz)
3
(No Transcript)
4
??F??????S? ?????G???? S?????S ? d?ad??as?a
µetat??p?? e??? s??e???? a?a??????? ???t????
s?µat?? se ??a? ??d??a ??f??? (digitzation)
5
??F??????S? ?????G???? S?????S ? d?ad??as?a
µetat??p?? e??? s??e???? a?a??????? ???t????
s?µat?? se ??a? ??d??a ??f???
de??µat?????a
?etaß???? p????t?ta?
?etaß???? ??. t?s??
?etat??p? µetaß???? se ??d??a ??f???
?ßa?t?sµ??
???pa?a???? st???e??
µ????f???
ADC
??d???p????
6
??F??????S? ?????G???? S?????S ? d?ad??as?a
µetat??p?? e??? s??e???? a?a??????? ???t????
s?µat?? se ??a? ??d??a ??f???
7
??F??????S? ?????G???? S?????S ? d?ad??as?a
µetat??p?? e??? s??e???? a?a??????? ???t????
s?µat?? se ??a? ??d??a ??f???
word
bit
0 0 0 0 1 1 0 0
0 1 0 0 1 1 0 0
0 1 0 1 1 1 00
0 1 0 0 1 1 0 0
byte
?etaß???? p?es??
?etaß???? t?s??
??f?a?? p????f???a
8
??F??????S? ?????G???? S?????S
9
??F??????S? ?????G???? S?????S
1. ?e??µat?????a
? ?aµ??? sample rate B ??a??p???t??? sample rate
10
??F??????S? ?????G???? S?????S
1. ?e??µat?????a
- ??st?te?? ap?d?s? - ?e????? ????? p????f???a?
11
??F??????S? ?????G???? S?????S
1. ?e??µat?????a
Te???µa Nyquist ? ???µ?? de??µat?????a? (Fs
sample rate) e??? s?µat?? ?a p??pe? ?a e??a?
t??????st?? d?p??s??? ap? t?? ????te?? a?µ?????
s???st?sa p?? pe????eta? st? s?µa
(Fmax) Fsgt2Fmax CD Quality Fs2Fn (22050Hz
cutoff frequency) 44100Hz ????f??? Fsgt2Fn
(3300Hz gtgt gtgt ) 8000Hz
12
??F??????S? ?????G???? S?????S
1. ?e??µat?????a
Aliasing fs lt 2fn
???????????? s????t?t??, pa?aµ??f?s?
Anti-alias filter afa??es? s????t?t??
µe?a??te??? ap? fs/2
13
??F??????S? ?????G???? S?????S
2. Kßa?t?sµ?? ? µetat??p? s??e??? t?µ?? p??t???
se d?a???t?? t?µ?? p??t??? (st??µe?)
????µ?? sta?µ?? / a???µ?? d?a??s?µ?? bits
S(n)Q(Sd(n))
14
??F??????S? ?????G???? S?????S
2. Kßa?t?sµ?? ? µetat??p? s??e??? t?µ?? p??t???
se d?a???t?? t?µ?? p??t??? (st??µe?)
St???????p???s? Sf??µa ?ßa?t?sµ??
?p?stas? sta?µ?? ??µa ?ßa?t?sµ?? (?)
(LSB)
?a???µ?? d?a??s?µ?? bits ? 2?d?a??s?µa
ep?peda ?ßa?t?sµ?? 1 bit 0,1 ????
?ßa?t?st? 2 bit 00, 01, 10, 11 ?a?a?t???st?
??? t?µ?? 8bit (256 st??µe?), 16 bit (65536
st??µe?), 24bit
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??F??????S? ?????G???? S?????S
2. Kßa?t?sµ?? ? µetat??p? s??e??? t?µ?? p??t???
se d?a???t?? t?µ?? p??t??? (st??µe?)
?etat??p? µe 2bit ADC ?1V Output 224 st??µe?
??µ? s?µat?? e??d?? sf??µa ?ßa?t?sµ?? ? Db / Noise
S(n)Sd(n)e(n)
Sd(n) Sd(n-1)gt? ?p???µ?t? s?????? ?ßa?t?sµ??
?? t?µ?? t?? s?µ?t?? e?s?d?? p??pe? ?a e??a?
a??et? µe?a??te?e? ap? t?? t?µ? t?? ß?µat??
?ßa?t?sµ??
16
??F??????S? ?????G???? S?????S
2. Kßa?t?sµ?? ? µetat??p? s??e??? t?µ?? p??t???
se d?a???t?? t?µ?? p??t??? (st??µe?)
SNR s?µat?????ß???? ????? t? p????? t?? ?s????
t?? s?µat?? ?? p??? t?? ?s?? t?? ????ß??
(dB). SNR Signal to Noise Ratio
20log10(2N) 90 Db ? d?af??? ????ß?? / s?µat??
sta pe??ss?te?a s?st?µata
17
??F??????S? ?????G???? S?????S

• TEXNIKES ???OS?S ????????? T??????
• ????s? t?? t???? ?ßa?t?st? (N)
• ???s???? ????ß?? dither µe p??t?? µe?a??te?? ap?
  t? ß?µa ?ßa?t?sµ?? ?
• Noise Shaping

4. ???????G?????????
18
??F??????S? ?????G???? S?????S

• TEXNIKES ???OS?S ????????? T??????
• ????s? t?? t???? ?ßa?t?st? (N)

(T?????) ?e??ss?te?e? st??µe? / µe?a??te??
ep?ped? ?ßa?t?sµ?? ?e?a??te?? a???ße?a
ape?????s?? ?????te?? sf??µa ?ßa?t?sµ?? ?e?a??te??
d??aµ??? e???? ?e??ss?te?e? d??at?t?te?
pe?a?t??? epe?e??as?a?
(????????) ?e?a??te??? ????? p????f???a?
(pe??ss?te?a bits) ?e???e? apa?t?se?? ?? p??? t?
???? ap????e?s?? ?e?a??te??? ??????
epe?e??as?a? ?a??st???s? µet?d?s??
19
??F??????S? ?????G???? S?????S

• TEXNIKES ???OS?S ????????? T??????
• ????s? t?? t???? ?ßa?t?st? (N)

(T?????) ?e??ss?te?e? st??µe? / µe?a??te??
ep?ped? ?ßa?t?sµ?? ?e?a??te?? a???ße?a
ape?????s?? ?????te?? sf??µa ?ßa?t?sµ?? ?e?a??te??
d??aµ??? e???? ?e??ss?te?e? d??at?t?te?
pe?a?t??? epe?e??as?a?
(????????) ?e?a??te??? ????? p????f???a?
(pe??ss?te?a bits) ?e???e? apa?t?se?? ?? p??? t?
???? ap????e?s?? ?e?a??te??? ??????
epe?e??as?a? ?a??st???s? µet?d?s??
20
??F??????S? ?????G???? S?????S

• TEXNIKES ???OS?S ????????? T??????
• ???s???? ????ß?? dither µe p??t?? µe?a??te?? ap?
  t? ß?µa ?ßa?t?sµ?? ?
• ???e? ?a?a?t???st??? ?e???? ????ß?? st? sf??µa
  ?ßa?t?sµ?? ?a? t? ?a??st? a?e???t?t? ap? t?
  ???t??? s?µa
• ?fa??e? t?? a?µ?????? pa?aµ?f?se?? sta s?µata
  µ????? p??t???
• ?????e? t? d??aµ??? pe????? t?? ?ßa?t?st?

21
??F??????S? ?????G???? S?????S

• TEXNIKES ???OS?S ????????? T??????
• ???s???? ????ß?? dither µe p??t?? µe?a??te?? ap?
  t? ß?µa ?ßa?t?sµ?? ?
• ???e? ?a?a?t???st??? ?e???? ????ß?? st? sf??µa
  ?ßa?t?sµ?? ?a? t? ?a??st? a?e???t?t? ap? t?
  ???t??? s?µa
• ?fa??e? t?? a?µ?????? pa?aµ?f?se?? sta s?µata
  µ????? p??t???
• ?????e? t? d??aµ??? pe????? t?? ?ßa?t?st?

? a???st?t?ta t?? ????ß?? a????eta? µe t?
s????t?ta (???eta? pe??ss?te?? a?t???pt?? µeta??
3-5 ??z).
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??F??????S? ?????G???? S?????S

• TEXNIKES ???OS?S ????????? T??????
• Noise Shaping
• µet??es? ????ß?? se ?????te?e? pe?????? t??
  ???t???? f?sµat??
• ?e?t?????a t? s?µa a?at??f?d?te?ta? µe a???t???
  a??d?as?. ?? a?at??f?d?t??µe?? s?µa afa??e?ta?
  ap? t? s?µa e?s?d?? ?a? a?t? p?? ap?µ??e? e??a?
  ? d?af??? t???, d??ad? t? sf??µa ?ßa?t?sµ?? e(n)

?e?t??s? 16 Db / s??d?asµ?? µe Dither
23
??F??????S? ?????G???? S?????S
TEXNIKES ???OS?S ????????? T?????? 4. Ype?de??µat
?????a ? de??µat?????a µe s????t?ta
p???ap??s?a t?? ??t??µe??? s????t?ta? (fs ? 2fs,
3fs)
48Khz ? 96Khz (2fs) ? 192Khz(4fs)
24
??F??????S? ?????G???? S?????S
TEXNIKES ???OS?S ????????? T?????? 4. Ype?de??µat
?????a ? de??µat?????a µe s????t?ta
p???ap??s?a t?? ??t??µe??? s????t?ta? (fs ? 2fs,
3fs)
48Khz ? 96Khz (2fs) ? 192Khz(4fs)
E??tt?s? ?ßa?t???? ????ß?? (pe??ss?te?e? t?µ??
de??µ?t??)
???at?t?ta e??tt?s?? t?? a???µ?? t?? bits (N)
25
??F??????S? ?????G???? S?????S
S??S? ???G?????????S - ??????S???
26
??F??????S? ?????G???? S?????S
S??S? ???G?????????S - ??????S???
???????? ?????F????S ???????? ???????GOG?S
27
??F??????S? ?????G???? S?????S
S??S? ???G?????????S - ??????S???
???????? ?????F????S ???????? ???????GOG?S
??????????S ??????G?S??S ?O??????????
??????? ???T????S? ??????????S ??????S?S
28
??F??????S? ?????G???? S?????S
S??S? ???G?????????S - ??????S???
????? p???t?ta p????f???a? (µe????? a???µ??
de??µ?t?? /t??? ?ßa?t?st?)
?p???µ?t?? s??d?asµ??
????? µ??e??? a??e??? (µ???? µ??e??? de??µat??)
29
??F??????S? ?????G???? S?????S
S??S? ???G?????????S - ??????S???
8 bit 16 bit 24 bit 32 bit
44.100 Hz / 16 bit CD Quality 96, 000 Hz / 24
bit DVD, (efa?µ???? epa??e?µat???? epe?e??as?a?
????)
30
??F??????S? ?????G???? S?????S
S??S? ???G?????????S - ??????S???
?O?????????? ???????
31
??F??????S? ?????G???? S?????S
S??S? ???G?????????S - ??????S???
?O?????????? ??????? ????t???t?ta (bytes)
s????t?ta (Hz) x µ??e??? de??µat?? (bits) x
d????e?a (sec) x a?.?a?a????
8 (bits) (µ??e??? byte)
32
??F??????S? ?????G???? S?????S
S??S? ???G?????????S - ??????S???
?O?????????? ??????? ????t???t?ta (bytes)
s????t?ta (Hz) x µ??e??? de??µat?? (bits) x
d????e?a (sec) x a?.?a?a????
8 (bits) (µ??e??? byte)
???? CD (1 sec)
33
??F??????S? ?????G???? S?????S
S??S? ???G?????????S - ??????S???
?O?????????? ??????? ????t???t?ta (bytes)
s????t?ta (Hz) x µ??e??? de??µat?? (bits) x
d????e?a (sec) x a?.?a?a????
8 (bits) (µ??e??? byte)
???? CD (1 sec)
44100(Hz) x 16(bits) x 1(sec) x 2(?a????a)
1,411,200 (bits) / 8 (bits) 176,400 bytes
34
??F??????S? ?????G???? S?????S
S??S? ???G?????????S - ??????S???
?O?????????? ??????? ????t???t?ta (bytes)
s????t?ta (Hz) x µ??e??? de??µat?? (bits) x
d????e?a (sec) x a?.?a?a????
8 (bits) (µ??e??? byte)
35
??F??????S? ?????G???? S?????S
3. K?d???p???s? a) ? a?t?st????s? t?? ??d????
p?? p????pt??? ap? t?? ?ßa?t?sµ? sta
de??µata ß) ? d?µ??????a se???? ??f???
0011011001011001110111101011...
(??f?a?? p????f???a)
ap????e?s?
µet?d?s?
ap???d???p???s? - pa?eµß???
(decoding) (interpolation)
36
??F??????S? ?????G???? S?????S
3. K?d???p???s? a) ? a?t?st????s? t?? ??d????
p?? p????pt??? ap? t?? ?ßa?t?sµ? sta
de??µata ß) ? d?µ??????a se???? ??f???
O??sµ??
??d???p???s? ? d?ad??as?a µetat??p?? e???
a?a??????? ???t???? s?µat?? se µ?a se???
??f??? ?p???d???p???s? (a?t?st??f? d?ad??as?a)
? d?ad??as?a µetat??p?? t?? ??f?a??
??d???p???µ???? ???t???? p????f???a? se a?a??????
???t??? s?µa
37
?p???d???p???s? (decoding)
Interpolation ??µ?????a ???? de??µ?t?? µeta??
a?t?? p?? ?d? ?p?????? µe ß?s? ??p??? a??????µ?
38
Bas???? µ???d?? ??d???p???s??
PCM (Pulse Code Modulation) ?a?µ???d???
??d???p???s?. ?e????st? ap????e?s? de??µ?t??,
??aµµ??? d?aµ??f?s?. Mu-Law / A-Law PCM
???a???µ??? ??d???p???s?. ??t?st????s?
pe??ss?te??? sta?µ?? st?? ?aµ????
s????t?te? DPCM (Differential Pulse Code
Modulation) ??af????? pa?µ???d??? ??d???p???s?.
??d???p???s? de??µat?? se s??s? µe ta p??????µe?a
(p????? ap????e?s? 1?? de??µat??, ap????e?s?
d?af???? ??a ta ep?µe?a de??µata). ??aµ??f?s?
???ta (Delta Modulation) 1bit? 1 µe?a??te??
e????, 0µ????te?? e???? ADPCM (Adaptive
Differential ulse Code Modulation)
???sa?µ???µe?? d?af????? pa?µ???d???
??d???p???s?. ???ß?e?? t?µ?? ? ?p?????sµ??
d?af???? µeta?? p?a?µat???? - p??ß?ep?µe???
t?µ??. LPC (Linear Predictive Coding) G?aµµ???
p??ß?ep?µe?? ??d???p???s?. S?????s?
?a?a?t???st???? t?? s?µat?? µe ??a ap????e?µ???
a?a??t??? µ??t???? µet?d?s? t?? ?a?a?t???st????
p?? s?µp?pt??? µe ta ?a?a?t???st??? t?? µ??t????.
(efa?µ??? se t??ep????????e?, s?µp?es? ?µ???a?)
39
???µ?? µet?d?s?? (bit rate)
40
???µ?? µet?d?s?? (bit rate)
e?f???e? t?? ta??t?ta d?µ??????a? ?a? µet?d?s??
??f?a??? ded?µ???? se µ?a s???e???µ??? µ???da
?????? ?ata t?? pa?a???? / a?apa?a???? / µet?d?s?
e??? pa?µ???d???? s?µat??
41
???µ?? µet?d?s?? (bit rate)
e?f???e? t?? ta??t?ta d?µ??????a? ?a? µet?d?s??
??f?a??? ded?µ???? se µ?a s???e???µ??? µ???da
?????? ?ata t?? pa?a???? / a?apa?a???? / µet?d?s?
e??? pa?µ???d???? s?µat??
µet???ta? se bits/sec
42
???µ?? µet?d?s?? (bit rate)
e?f???e? t?? ta??t?ta d?µ??????a? ?a? µet?d?s??
??f?a??? ded?µ???? se µ?a s???e???µ??? µ???da
?????? ?ata t?? pa?a???? / a?apa?a???? / µet?d?s?
e??? pa?µ???d???? s?µat??
µet???ta? se bits/sec
p????pte? ap? t? ????µe?? t?? s????t?ta?
de??µat?????a? x µ??e??? de??µat?? (bits a??
de??µa) (? s??s? de??µat?????a?
?ßa?t?sµ??) IFsN (stereo signals
I2FsN) ??. Fs8000 (de??µata a?a
de?te???ept?) N8 bits ? I 64kbps
43
???µ?? µet?d?s?? (bit rate)
e?f???e? t?? ta??t?ta d?µ??????a? ?a? µet?d?s??
??f?a??? ded?µ???? se µ?a s???e???µ??? µ???da
?????? ?ata t?? pa?a???? / a?apa?a???? / µet?d?s?
e??? pa?µ???d???? s?µat??
µet???ta? se bits/sec
p????pte? ap? t? ????µe?? t?? s????t?ta?
de??µat?????a? x µ??e??? de??µat?? (bits a??
de??µa) (? s??s? de??µat?????a?
?ßa?t?sµ??) IFsN (stereo signals
I2FsN) ??. CD Stereo 1,44Mbps
44
??F??????S? ???? S????????

• ?e??µat?????a
• Sd(n) Sc(nTs)
• ?a?a???? de??µ?t?? (samples), d?aµ??f?s? pa?µ??
  (PAMPulse Amplitude Modulation)
• fs1/Ts (sampling frequency sample rate)
• fs2fn (s????t?ta Nyquist)
• ?ßa?t?sµ??
• S(n)Q(Sd(n)), S(n)Sd(n)e(n)
• ?etat??p? s??e??? t?µ?? p??t??? se d?a???t??
• ?t??? ?ßa?t?st? / µe?e??? de??µat??
• 2?ep?ped? ?ßa?t?sµ?? / a???µ?? d?a??s?µ?? bits
• ??µa ?ßa?t?sµ?? (?)
• Sf??µa ?ßa?t?sµ??
• ??d???p???s?
• ??t?st????s? ??d???? ?ßa?t?sµ?? sta de??µata,
  d?µ??????a se???? ??f??? / ??f?a??? p????f???a?
  (d?ad???? ??d??a?)
• ?p???d???p???s? (decoding) / ??ad??as?a
  pa?eµß???? (interpolation)