1 8 de febrero del 2001. 2 chapter 5 encoding 3 figure 5-1 different conversion schemes
TRANSCRIPT
1
8 de febrero del 20018 de febrero del 2001
2
Chapter 5
Encoding
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Figure 5-1
Different Conversion Schemes
4
Figure 5-2
Digital to Digital Encoding
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Figure 5-3
Types of Digital to Digital Encoding
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Figure 5-4
Unipolar Encoding
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Figure 5-5
Types of Polar Encoding
8
NRZL
Especificación del Protocolo:
( )
( )−
+
→=
→=
V DD
V DD
transmiter
0 ::
1 ::
()
( )
( ) 0::
1 ::
()
=→
=→−
+
DD V
DDV
reciever
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Figure 5-6
NRZ-L and NRZ-I Encoding
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Figure 5-7
RZ Encoding
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Bifase (Auto-Sincronizados)Bifase (Auto-Sincronizados)
Siempre hay una transición a mitad del intervalo de duración del bit.
TécnicasManchester: La transición de mitad del intervalo
sirve para sincronización y transmisión de datos.Manchester Diferencial: La transición de mitad del
intervalo solo sirve para sincronización
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Manchester
( ) ( )
( ) ( )+−
−+
→=
→=
V V DD
V V DD
transmiter
,0 ::
,1 ::
()
( )
( )
( )
( )+
+
+
−
=→
=→
V
DD V
V
DDV
reciever
1::
0 ::
()
Especificación del Protocolo:
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Figure 5-8Manchester and Diff. Manchester Encoding
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1. ¿Cuál es la capacidad de un canal de 5kHz que utiliza codificación Manchester?
2. ¿Y si utilizara codificación MLT-3?
)2(log)58(2log2.1 22 kHzVHC ==bps000,10=
)3(log)5(2log2.2 22 kHzVHC ==bps850,15=
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Figure 5-9
Types of Bipolar Encoding
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Binario MultinivelBinario Multinivel
Técnicasbiploar-AMI (“Alternate Mark Inversion”)pseudoternarioMLT-3 (Multi-Level Transmit - 3 Levels)2B1Q
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Bipolar-AMI
( )
( )
( )
( )00 ::
~1 ::
':
()
V DD
VB
B, V DD
VBci
transmiter
c
c
→=
=
=→=
= +
( ) ( )
( ) 0::
1|| ::
()
0 =→
=→−+
DD V
DDVV
reciever
Especificación del Protocolo:
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Figure 5-10
Bipolar AMI Encoding
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Figure 5-11
B8ZS Encoding
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Figure 5-12
HDB3 Encoding
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Figure 5-13
Solution to Example 5.1
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Figure 5-14
Solution to Example 5.2
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Figure 5-15
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Analog to Digital Encoding
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Figure 5-16
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PAM
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Figure 5-17
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Quantized PAM Signal
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Figure 5-18
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Quantizing Using Sign and Magnitude
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Figure 5-19
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PCM
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Figure 5-20
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From Analog to PCM
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Figure 5-20-continued
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From Analog to PCM
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Figure 5-20-continued
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From Analog to PCM
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Figure 5-20-continued
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
From Analog to PCM
S k
S k ~
S (t) ~
S(t)
⎩⎨⎧
=≥
=fsTs
fwfsfwTs
Nyquist
/1
22/1
76.102.6 += nSNRdB
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Figure 5-21
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Nyquist Theorem
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Figure 5-22
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Digital to Analog Encoding
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Figure 5-23
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
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ASKASK
Especificación del Protocolo:
1
0
1 ::
0 ::
()
A DD
A DD
transmiter
→=→=
DDA
DD A
reciever
1 ::
0::
()
1
0
=→=→
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Figure 5-24
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ASK
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Figure 5-25
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
Bandwidth for ASK
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FSKFSK
Especificación del Protocolo:
1
0
1 ::
0 ::
()
f DD
f DD
transmiter
→=→=
DDf
DD f
reciever
1 ::
0::
()
1
0
=→=→
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FSKFigure 5-27
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Bandwidth for FSKFigure 5-28
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PSKPSK
Especificación del Protocolo:
1
0
1 ::
0 ::
()
ϕϕ DD DD
transmiter
→=→=
DD
DD
reciever
1 ::
0::
()
1
0
=→=→
ϕϕ
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PSKFigure 5-29
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
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PSKConstellation
Figure 5-30
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
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4-PSKFigure 5-31
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4-PSKCharacteristics
Figure 5-32
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8-PSKCharacteristics
Figure 5-33
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PSKBandwidth
Figure 5-34
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QAM (4)QAM (4)
Especificación del Protocolo
30
20
10
00
11 ::
10 ::
01 ::
00 ::
()
ϕϕϕϕ
A DD A DD A DD A DD
transmiter
→=→=→=→=
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QAM(Quadratura Amplitude Modulation)
QAM(Quadratura Amplitude Modulation)
Re00
01
10
1101
00
01
10
11
11 00 01 1010
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4-QAM and 8-QAMConstellations
Figure 5-35
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
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QAM (8)QAM (8)
Especificación del
protocolo
31
21
11
01
30
20
10
00
111 ::
110 ::
101 ::
100 ::
011 ::
010 ::
001 ::
000 ::
()
ϕϕϕϕϕϕϕϕ
A DD A DD A DD A DD A DD A DD A DD A DD
transmiter
→=→=→=→=→=→=→=→=
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Re000
001
010
011
100101
110 111
000
001
010
011
011011000110
100
101
110
111
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8-QAM SignalFigure 5-36
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16-QAMConstellation
Figure 5-37
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Bit Rate and Baud Rate
Figure 5-38
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Figure 5-38-continued
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
Bit Rate and Baud Rate
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Datos Digitales-Señales Análogas
Datos Digitales-Señales Análogas
Aplicación en Redes Públicas de Datos
Aplicación en Redes de Área Local
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Problema 1. Problema 1.
¿Cuál es el periodo de muestreo que necesita una señal análoga que tiene un ancho de banda de 20 Khz?
.40
)025.0(1
)20*2/(1
msegT
T
KhzT
s
s
s
===
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Problema 2. Problema 2.
¿Cuál es la razón de señal de ruido, si se utilizan 8 niveles para discretizar linealmente la amplitud de la señal?
82.19
76.106.18
76.1)3(02.6
=+=+=
dB
dB
dB
SNRSNRSNR
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Problema 3. Problema 3.
¿Cuál es la razón de datos de una señal discretizada a 8 niveles (3 bits) con un periodo de muetreo de 0.1 mseg.?
bpsRD
msegbitsRD
000,30
1.0/3
==
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Figure 5-39
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
Analog to Analog Modulation
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Figure 5-40
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
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Figure 5-41
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
Amplitude Modulation
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Figure 5-42
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AM Bandwidth
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Figure 5-43
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AM Band Allocation
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Figure 5-44
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
Frequency Modulation
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Figure 5-45
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
FM Bandwidth
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Figure 5-46
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
FM Band Allocation
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Cap. 6
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Figure 6-19
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Modem
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Bandwidth for Telephone LineFigure 6-20
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Baud Rate for Half-Duplex ASK
Figure 6-21
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Baud Rate for Full-Duplex ASK
Figure 6-22
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Baud Rate for Half-Duplex FSK
Figure 6-23
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
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Baud Rate for Full-Duplex FSK
Figure 6-24
WCB/McGraw-Hill The McGraw-Hill Companies, Inc., 1998
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Bell Modems
Figure 6-25
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Bell Modems
Figure 6-25-continued
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ITU ModemsFigure 6-26-continued
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V.22bis 16-QAM ConstellationFigure 6-27
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V.32 ConstellationFigure 6-28
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V.33 ConstellationFigure 6-29
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