Brief Description of Vector Signal Analysis
R&S
®
FSV-K70
38
Operating Manual 1176.7578.02 ─ 09
00
01
02
03
04
05
06
07
08
09
0A 0B
0C
0D
0E
0F
10
11
12
13
14
15
16
17
18
19
1A
1B
1C 1D
1E
1F
20
21
22
23
24
25
26
27
28
29
2A 2B
2C
2D
2E
2F
30
31
32
33
34
35
36
37
38
39
3A
3B
3C 3D
3E
3F
Figure 2-37: Constellation diagram for 256QAM including the logical symbol mapping (hexadecimal);
the figure shows the upper right section of the diagram only
2.3.9 User QAM
In the case of a User QAM modulation, the information can be represented by the sig-
nal amplitude and/or the signal phase.
16APSK
C
D
E
F
R2
R1
0
1
2
3
4
5
6
7
8
9
A
B
Figure 2-38: Constellation diagram for 16APSK including the logical symbol mapping for DVB-S2
For DVB-S2 16APSK mappings, the ratio of the outer circle radius to the inner circle
radius (
γ
= R2/R1) depends on the utilized code rate and complies with
Table 2-17: Optimum constellation radius ratio
γ
(linear channel) for 16APSK
Code Rate
Modulation / coding spectral
efficiency
γ
2/3
2.66
3.15
3/4
2.99
2.85
4/5
3.19
2.75
Symbol Mapping
Содержание FSV-K70
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