### Wireless Communication Network Lab

```單元七 差異(delta)調變與解調
Wireless Communication Network Lab.

[email protected]
http://wcnlab.niu.edu.tw

Wireless Communication Network Lab.
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(Continuously Variable Slope Delta，CVSD)調

EE of NIU
Chih-Cheng Tseng
2

Wireless Communication Network Lab.
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(Pulse Code Modulation，PCM)則是每一個取樣要用多

EE of NIU
Chih-Cheng Tseng
3

Wireless Communication Network Lab.
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®É¯ß¿é¤J
Ãþ¤ñ¿é¤J
_
Vi
¼Æ¦ì¿é¥X
¤ñ¸û¾¹
Vp
Vd
¼Æ¦ì¿é¤J
¨ú¼Ë
Ãþ¤ñ¿é¥X
Va
Vd
¿n¤À¾¹
+
¹w´ú¹qÀ£
¿n¤À¾¹

EE of NIU
Chih-Cheng Tseng
4

Wireless Communication Network Lab.
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(1)當類比輸入 Vi大於預測電壓Vp時，比較器輸

(2)當類比輸入Vi小於預測電壓Vp時，比較器輸

EE of NIU
Chih-Cheng Tseng
5

Wireless Communication Network Lab.
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(3)綜合(1)(2)兩種狀況，各端點之波形如圖 7-2

(4)由(3)之敘述可得知，在解調端只要將接收

EE of NIU
Chih-Cheng Tseng
6

Wireless Communication Network Lab.
®É¯ß¿é¤J
Ãþ¤ñ¿é¤J
¹w´ú¹qÀ£
(Ãþ¤ñ¿é¥X)
¼Æ¦ì¿é¥X

EE of NIU
Chih-Cheng Tseng
7

Wireless Communication Network Lab.
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•
•
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[參考圖 7-3(a)]。

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•

EE of NIU
Chih-Cheng Tseng
8

Wireless Communication Network Lab.

(類 比 輸 出 )

(a) 斜 率 太 小 時

EE of NIU
Chih-Cheng Tseng
9

Wireless Communication Network Lab.

(類 比 輸 出 )

(b) 斜 率 太 大 時

EE of NIU
Chih-Cheng Tseng
10

Wireless Communication Network Lab.
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• 當斜率夠大(積分器輸出足以跟上輸入Vi的變化 )

EE of NIU
Chih-Cheng Tseng
11

Wireless Communication Network Lab.
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• 當監測電路發現連續出現n個(本單元電路之n=3)相
•

High信號給積分器，使積分器之斜率持續縮小。
EE of NIU
Chih-Cheng Tseng
12

Wireless Communication Network Lab.

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(channel idle)]，調變端最好能送出High、Low

EE of NIU
Chih-Cheng Tseng
13
CVSD調變器 (1/2)
+5V
Wireless Communication Network Lab.
+
Ra
8
2.2 u
4
1k
7
Rb
6
3
CLK-out
555
33k
2
0.0 01u
5
0.1 u
Cb
1
M/ I
15
3.3 u
+
A-in
1
#1
2
560
560
9
_
+
13
Shi ft
16
Q Q Q
#2
D-in
+5V
Reg ister
_
D-out
14
Rp
+
3.3 k
12
11
Vcc /2
R1
10k
0.1 u
+
Log ic
10
Rs
5
0.3 3u
33k
+
_
7
1k

Cs
+5V
3
Cur rent
Sw itch
Rx
4
1.2 k
A-out
1k
EE of NIU
R
10k
C
0.0 47u
6
MC34115
8
Rmin
2.2 M
Chih-Cheng Tseng
14
CVSD調變器 (2/2)
Wireless Communication Network Lab.
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D-out端輸出為0 V、5 V之數位方波。
EE of NIU
Chih-Cheng Tseng
15
CVSD調變器電路分析 (1/5)
Wireless Communication Network Lab.
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EE of NIU
Chih-Cheng Tseng
16
CVSD調變器電路分析 (2/5)
Wireless Communication Network Lab.
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EE of NIU
Chih-Cheng Tseng
17
CVSD調變器電路分析 (3/5)
Wireless Communication Network Lab.
C L K -in
A -in
A -o u t
D -o u t
(a) 積 分 斜 率 適 中

EE of NIU
Chih-Cheng Tseng
18
CVSD調變器電路分析 (4/5)
Wireless Communication Network Lab.
C L K -in
A -in
A -o u t
D -o u t
(b) 積 分 斜 率 太 小
(續)圖 U8-4 CVSD 之運作情形
EE of NIU
Chih-Cheng Tseng
19
CVSD調變器電路分析 (5/5)
Wireless Communication Network Lab.
C L K -in
A -in
A -o u t
D -o u t
(c) 積 分 斜 率 太 大
(續)圖 U8-4 CVSD 之運作情形
EE of NIU
Chih-Cheng Tseng
20

Wireless Communication Network Lab.

EE of NIU
Chih-Cheng Tseng
21

Wireless Communication Network Lab.
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Vi  

VCC
2
 V i ( ac )
(U8-1)

EE of NIU
Chih-Cheng Tseng
22

Wireless Communication Network Lab.

EE of NIU
Chih-Cheng Tseng
23

Wireless Communication Network Lab.
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EE of NIU
Chih-Cheng Tseng
24

Wireless Communication Network Lab.

EE of NIU
Chih-Cheng Tseng
25

Wireless Communication Network Lab.
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|IINT|與IGC約成正比關係，而IGC=(5-V4 )/RX 。又
V3≈V4，所以
I GC 
EE of NIU
5  V3
RX
Chih-Cheng Tseng
(U8-2)
26

Wireless Communication Network Lab.
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• V3將往(Rmin/(RP+RS+Rmin)5V≈5V上升，
• 再由 (U8-2) 式可得IGC將往0 mA下降，而下降的速



EE of NIU
Chih-Cheng Tseng
27

Wireless Communication Network Lab.
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• V3將往0 V下降，
• 再由(U8-2)式可得IGC將往5/RX上升，而上升的速度

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RSCS有關， RSCS越小則斜率增大得越快。

EE of NIU
Chih-Cheng Tseng
28

Wireless Communication Network Lab.
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• 積分電容C越小則積分斜率越大。
• 電阻RX越小則積分斜率越大。
• (RP+RS)CS越小則斜率縮小時會縮小得越快。
• RSCS越小則斜率增大時會增大得越快。
• Rmin會影響到斜率之最小值，而且當Rmin不夠大時，

EE of NIU
Chih-Cheng Tseng
29

Wireless Communication Network Lab.
+ 5V
+
Ra
8
2.2 u
4
1k
7
Rb
6
3
CLK-ou t
55 5
33k
2
0.0 01u
5
0.1 u
Cb
1

EE of NIU
Chih-Cheng Tseng
30

Wireless Communication Network Lab.
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f0 
EE of NIU
1.44
( R a  2 Rb )C b
 21.5 kH z
Chih-Cheng Tseng
31
CVSD 解調器
Wireless Communication Network Lab.
15
1
+
13
D-out
H
#1
2
D-in
9
_
14
Shi ft
L
_
+5V
Reg ister
16
Q Q Q
#2
Rp
+
3.3 k
12
11
Vcc /2
Rs
5
0.1 u
+
_
7
1k
Cs
0.3 3u
33k
MC 34115
10k
+
Log ic
10
R1
CLK-in
+5V
3
Cur rent
Sw itch
Rx
4
1.2 k
1k
6
R
10k
C
0.0 47u
8
Rmin
2.2 M
A-out

EE of NIU
Chih-Cheng Tseng
32
CVSD 調解器電路分析 (1/2)
Wireless Communication Network Lab.
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CVSD 解調器之結構如圖 U8-9 所示，其運作原理如下：
®É¯ß¿é¤J
CLK-in
¼Æ¦ì¿é¤J
¼Æ¦ì¿é¥X
¨ú¼Ë
D-in
D-out
¿n¤À¾¹
ºÊ´ú
(±×²v±±¨î)
¹q¸ô
Ãþ¤ñ¿é¥X
A-out

EE of NIU
Chih-Cheng Tseng
33
CVSD解調器電路分析 (2/2)
Wireless Communication Network Lab.
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D-in端為數位輸入端，A-out端為類比輸出端，
CLK-in為時脈輸入端。

EE of NIU
Chih-Cheng Tseng
34
MC34115內的反相器
Wireless Communication Network Lab.
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U8-10所示。由於MC34115之PIN 15接地，所

_
D-in
#2
¨ú¼Ë
+
Vc c /2

EE of NIU
Chih-Cheng Tseng
35

Wireless Communication Network Lab.
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Low交替的信號，將有助於讓接收端保持位元同步。
EE of NIU
Chih-Cheng Tseng
36

Wireless Communication Network Lab.
®É¯ß
²£¥Í¾¹
®É¯ß¿é¥X
CLK-out
D-in
¼Æ¦ì¿é¥X
_
#2
¨ú¼Ë
D-out
+
Vcc /2

EE of NIU
Chih-Cheng Tseng
37
CVSD 調變、解調實驗電路
Wireless Communication Network Lab.
+5 V
+
Ra
8
2. 2u
4
1k
7
Rb
CLK-out
3
6
555
33k
2
5
+5V
0. 001u
15
0. 1u
Cb
1
1
M/I
+
Vi
1
A-in
_
#1
2
560
560
+
13
_
10k
10k
Rs
5
+
_
7
1k
0. 33u
+
Logic
Cu rr ent
Sw itch
Rx
4
+5 V
1. 2k
Rx
4
+5 V
3
3
Cu rr ent
Sw itch
Cs
0. 33u
33k
MC34 115
Cs
0. 1u
Rs
+
_
7
3. 3k
11
R1
+
33k
1k
+
3. 3k
CLK-in
Rp
Vc c/2
11
5
16
Q Q Q
10
Logic
Vc c/2
+5 V
Re gister
12
Rp
12
0. 1u
_
D-in
14
Shift
L
#2
+5 V
Q Q Q
10
+
13
16
+
R1
Vd
D-out
14
Shift
Re gister
#2
D-in
Vd
9
H
#1
2
15
3. 3u
D-out
9
_
R
10k
C
0. 047u
6
8
Rmin
2. 2M
1. 2k
Vp
R
10k
6
MC34 115
8
Rmin
1k
2. 2M
Va
A-out
A-out
1k
C
0. 047u

EE of NIU
Chih-Cheng Tseng
38
CVSD 調變、解調實驗電路電路說明
Wireless Communication Network Lab.
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EE of NIU
Chih-Cheng Tseng
39
```