Main Page » History » Version 22

Cuadro, Juan Pablo, 11/25/2014 09:39 PM

1 3 Cuadro, Juan Pablo
h1. Wiki
2 2 Cuadro, Juan Pablo
3 19 Cuadro, Juan Pablo
----
4 19 Cuadro, Juan Pablo
5 20 Cuadro, Juan Pablo
This is the Wiki page for the SCS 2014/2015 project #1. It deals with DVB-S2 and its novel ACM feature.
6 20 Cuadro, Juan Pablo
7 19 Cuadro, Juan Pablo
h2. Progress
8 19 Cuadro, Juan Pablo
9 19 Cuadro, Juan Pablo
----
10 19 Cuadro, Juan Pablo
11 19 Cuadro, Juan Pablo
@Tasks:@
12 19 Cuadro, Juan Pablo
13 21 Cuadro, Juan Pablo
* %{background: none}@Test Setup Section:@%
14 19 Cuadro, Juan Pablo
** %{background: yellow}@Introduction to each equipment@%
15 19 Cuadro, Juan Pablo
** %{background: yellow}@Network diagram of full setup@%
16 1 Cuadro, Juan Pablo
** %{background: yellow}@Single diagram for each modem and associated client PC@%
17 1 Cuadro, Juan Pablo
** %{background: yellow}@Full settings for modems (ACM mode as well as CCM mode)@%
18 1 Cuadro, Juan Pablo
** %{background: yellow}@Table with IPs@%
19 19 Cuadro, Juan Pablo
20 21 Cuadro, Juan Pablo
@ColorReference:@
21 21 Cuadro, Juan Pablo
* %{background: Lightgreen}@Task 1, Status: DONE@%
22 21 Cuadro, Juan Pablo
* %{background: yellow}@Task 2, Status: TODO@%
23 21 Cuadro, Juan Pablo
** %{background: Red}@SubTask 1, Status: URGENT@%
24 4 Cuadro, Juan Pablo
25 4 Cuadro, Juan Pablo
h2. INTRODUCTION {TODO}
26 4 Cuadro, Juan Pablo
27 19 Cuadro, Juan Pablo
----
28 19 Cuadro, Juan Pablo
29 8 Cuadro, Juan Pablo
Satellite systems based on the DVB-S standard are inevitably forced to adhere to fixed MODCOD parameters, that is, a fixed coding rate and modulation scheme. This in turn leaves the designer with no choice other than to dimension the system for the worst-case propagation conditions in order to have link-closure and meet availability, coverage and performance requirements. 
30 5 Cuadro, Juan Pablo
31 5 Cuadro, Juan Pablo
This approach has the disadvantage that high margins in the carrier-to-noise-and-interference ratios (CNIRs) occur in the majority of cases when propagation conditions allow for it. In the case of broadcasting services, where we have a multitude of users spread over very large areas, this waste of power cannot be easily avoided. However, in point-to-point links if a return channel is present it is possible to report channel state conditions and exploit its temporal variations by adapting the code rate and modulation scheme being used so as to best match the CNIR. This way a fixed link is avoided and considerable improvements in system capacity are obtained with better utilization of power resources.
32 5 Cuadro, Juan Pablo
33 5 Cuadro, Juan Pablo
The DVB-S2 standard introduces adaptive coding and modulation (ACM) enabling better use of transponder resources when high carrier-to-noise-plus-interference ratios occur due to favorable propagation conditions. ACM allows for different coding rates and modulation schemes to be used and dynamically changed on a frame-by-frame basis.
34 5 Cuadro, Juan Pablo
35 18 Cuadro, Juan Pablo
!{width: 50%}fig12.png(Block diagram of an ACM DVB-S2 link.)!
36 15 Cuadro, Juan Pablo
37 15 Cuadro, Juan Pablo
(CHANGE! FIGURE SIMILAR TO FIGURE12 in "ETSI-TR.102376":http://webapp.etsi.org/WorkProgram/Report_WorkItem.asp?WKI_ID=21402&curItemNr=1&totalNrItems=1&optDisplay=10&titleType=all&qSORT=HIGHVERSION&qETSI_ALL=&SearchPage=TRUE&qETSI_STANDARD_TYPE=%27TR%27&qETSI_NUMBER=102376&qINCLUDE_SUB_TB=True&qINCLUDE_MOVED_ON=&qSTOP_FLG=N&qKEYWORD_BOOLEAN=OR&qCLUSTER_BOOLEAN=OR&qFREQUENCIES_BOOLEAN=OR&qSTOPPING_OUTDATED=&butExpertSearch=Search&includeNonActiveTB=FALSE&includeSubProjectCode=FALSE&qREPORT_TYPE=SUMMARY) {TODO}
38 5 Cuadro, Juan Pablo
39 4 Cuadro, Juan Pablo
h2. DVB-S2 {TODO}
40 4 Cuadro, Juan Pablo
41 19 Cuadro, Juan Pablo
----
42 19 Cuadro, Juan Pablo
43 19 Cuadro, Juan Pablo
44 13 Cuadro, Juan Pablo
h2. TEST SETUP {TODO}
45 4 Cuadro, Juan Pablo
46 19 Cuadro, Juan Pablo
----
47 19 Cuadro, Juan Pablo
48 19 Cuadro, Juan Pablo
49 10 Cuadro, Juan Pablo
Setup diagrams:
50 10 Cuadro, Juan Pablo
51 12 Cuadro, Juan Pablo
!{width: 70%}fullsetup.png!
52 10 Cuadro, Juan Pablo
53 22 Cuadro, Juan Pablo
54 22 Cuadro, Juan Pablo
!{width: 70%}modemSetup.png!
55 22 Cuadro, Juan Pablo
56 7 Cuadro, Juan Pablo
[[EL470_LogParser_ACM]]
57 7 Cuadro, Juan Pablo
58 4 Cuadro, Juan Pablo
h2. MEASUREMENTS {TODO}
59 19 Cuadro, Juan Pablo
60 19 Cuadro, Juan Pablo
----