Modern Possibilities of Access and Transport Networks

1
Modern Possibilities of Access and Transport
Networks

• Vladislav Skorpil

2
The principle of Time Division Multiplex
3
(No Transcript)
4
(No Transcript)
5
The Principle of Pulse Code Modulation (PCM)
6
The Principle of Delta Modulation (DM) and
Adaptivre delta Modulation (ADM)
7
(No Transcript)
8
(No Transcript)
9
(No Transcript)
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
(No Transcript)
14
Adaptive Diferential PCM - ADPCM

• For signal with no constant midle power, samples
  are adapted to constant midle power

15
The basic block diagram for TDM system with
digital modulation

• Older type
• Common codec

16
Transmiter part
17
Receiver part
18
The basic block diagram for TDM system with
digital modulation

• Modern type
• Individual codec

19
(No Transcript)
20
Quantizing step encoder
21
(No Transcript)
22
Weighting encoder (Bit encoder)
23
(No Transcript)
24
Counting Analogue to Digital Convertor
25
Tracking A/D Convertor
26
Parallel A/D Convertor
27
Compenzating A/D Convertor
28
Shannon decoder
29
Shannon decoder response
30
Shannon Rack decoder
31
Shannon-Rack Decoder Response
32
Weighting Decoder (Bit Encoder)
33
Operational Amplifier
34
D/A Convertor with weighting resistors
35
D/A Convertor with cross piece structure of
resistor networks
36
D/A Convertor with current sources
37
Compandors and non-linear encoders
38
Compression and expansion characteristics
39
A-low compression characteristic
40
Unipolar and Bipolar Signal, Signal NRZ, RZ, TPC,
SPC, HDB3,AMI
41
Code HDB3

• Maximal 3 zeroes in sequence
• When the sequence of 4 or more zeroes exist, then
  forth one is encoded as the impulse with the same
  polarity as the previous one
• This bipolarity interruption must be positive
  after negative and negative after possitive (zero
  direct current part)

42
Isolation impulse
43
Identification of impulse
44
Decision eye bipolar signal
45
Decision eye unipolar signal, basic noise
46
Influence of impulse interference
47
Influence of jitter
48
Generation of AMI signal
49
Quantizing distortion
50
Peak limiting
51
(No Transcript)
52
(No Transcript)
53
Time behaviour of sampling
54
Spectrum of sampling signal PAM 1st sort
55
Ideal PAM 1st order (wide of samples approaches
to zero
56
Spestrum of sampling signal -2nd order
57
Spectrum of PAM 2nd order wide of samples
equals to sampling periode
58

• This is the end of my slides to the theme Modern
  possibilities of access and transport networks
• If you have any questions, you can write e-mail
  to
• skorpil_at_feec.vutbr.cz