Main Page » History » Version 27

Cuadro, Juan Pablo, 11/25/2014 10:30 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 25 Cuadro, Juan Pablo
+@Tasks:@+
12 19 Cuadro, Juan Pablo
13 24 Cuadro, Juan Pablo
* %{background: none}@Introduction Section:@%
14 24 Cuadro, Juan Pablo
** %{background: lightgreen}@Why ACM is necessary.@%
15 27 Cuadro, Juan Pablo
** %{background: lightgreen}@Block diagram of ACM functionality.@%
16 24 Cuadro, Juan Pablo
* %{background: none}@DVB-S2 Section:@%
17 24 Cuadro, Juan Pablo
** %{background: yellow}@A little bit of history.@%
18 24 Cuadro, Juan Pablo
** %{background: yellow}@Features vs DVB-S.@%
19 24 Cuadro, Juan Pablo
** %{background: yellow}@Coding and modulation schemes.@%
20 21 Cuadro, Juan Pablo
* %{background: none}@Test Setup Section:@%
21 19 Cuadro, Juan Pablo
** %{background: yellow}@Introduction to each equipment@%
22 19 Cuadro, Juan Pablo
** %{background: yellow}@Network diagram of full setup@%
23 23 Cuadro, Juan Pablo
** %{background: lightgreen}@Single diagram for each modem and associated client PC@%
24 1 Cuadro, Juan Pablo
** %{background: yellow}@Full settings for modems (ACM mode as well as CCM mode)@%
25 1 Cuadro, Juan Pablo
** %{background: yellow}@Table with IPs@%
26 19 Cuadro, Juan Pablo
27 25 Cuadro, Juan Pablo
+@ColorReference:@+
28 21 Cuadro, Juan Pablo
* %{background: Lightgreen}@Task 1, Status: DONE@%
29 21 Cuadro, Juan Pablo
* %{background: yellow}@Task 2, Status: TODO@%
30 21 Cuadro, Juan Pablo
** %{background: Red}@SubTask 1, Status: URGENT@%
31 4 Cuadro, Juan Pablo
32 4 Cuadro, Juan Pablo
h2. INTRODUCTION {TODO}
33 4 Cuadro, Juan Pablo
34 19 Cuadro, Juan Pablo
----
35 19 Cuadro, Juan Pablo
36 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. 
37 5 Cuadro, Juan Pablo
38 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.
39 5 Cuadro, Juan Pablo
40 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.
41 5 Cuadro, Juan Pablo
42 27 Cuadro, Juan Pablo
!{width: 70%}modemLink.png(Block diagram of an ACM DVB-S2 link.)!
43 15 Cuadro, Juan Pablo
44 27 Cuadro, Juan Pablo
(Similar to fig12 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}
45 5 Cuadro, Juan Pablo
46 4 Cuadro, Juan Pablo
h2. DVB-S2 {TODO}
47 4 Cuadro, Juan Pablo
48 19 Cuadro, Juan Pablo
----
49 19 Cuadro, Juan Pablo
50 19 Cuadro, Juan Pablo
51 13 Cuadro, Juan Pablo
h2. TEST SETUP {TODO}
52 4 Cuadro, Juan Pablo
53 19 Cuadro, Juan Pablo
----
54 19 Cuadro, Juan Pablo
55 19 Cuadro, Juan Pablo
56 26 Cuadro, Juan Pablo
The laboratory setup consits of the following:
57 1 Cuadro, Juan Pablo
58 26 Cuadro, Juan Pablo
(EQUIPMENT LIST AND DESCRIPTION)
59 26 Cuadro, Juan Pablo
60 26 Cuadro, Juan Pablo
61 12 Cuadro, Juan Pablo
!{width: 70%}fullsetup.png!
62 1 Cuadro, Juan Pablo
63 26 Cuadro, Juan Pablo
64 26 Cuadro, Juan Pablo
All two modems will be working in L2 Ethernet bridging mode. This means that we could use PCs to generate traffic between HUB and station or we could attach other devices such as VoIP phones or any other IP capable device.
65 22 Cuadro, Juan Pablo
66 22 Cuadro, Juan Pablo
!{width: 70%}modemSetup.png!
67 22 Cuadro, Juan Pablo
68 7 Cuadro, Juan Pablo
[[EL470_LogParser_ACM]]
69 7 Cuadro, Juan Pablo
70 4 Cuadro, Juan Pablo
h2. MEASUREMENTS {TODO}
71 19 Cuadro, Juan Pablo
72 19 Cuadro, Juan Pablo
----