ANÁLISIS DE INTERFERENCIA CO-CANAL EN …ANÁLISIS DE INTERFERENCIA CO-CANAL EN SISTEMAS DVB-S...

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ANÁLISIS DE INTERFERENCIA CO-CANAL

EN SISTEMAS DVB-S

CO-CHANNEL INTERFERENCE ANALYSIS IN DVB-S SYSTEMS

Ing. Aurora Fernández Bezanilla

Ms.C. Abdel Martínez Alonso

Marzo 2013

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ABSTRACT

This presentation describes 3 experiments that characterize the

DVB-S performance and ruggedness against co-channel

interference. In Experiment 1 was measured the carrier to

interference threshold for the reception in DVB-S system. In

Experiment 2, was determined the bit error ratio threshold for a

range of C/I levels in the vicinity of the threshold value obtained in

the previous experiment. In Experiment 3 was determined the

system response against periodic and burst signals within the

operating band.

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TOPICS

• Digital TV via Satellite. DVB-S standard.

• C/I and BER thresholds for the reception in the DVB-S system.

• DVB-S performance against interference noise.

Experiments results.

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Two TV by satellite distribution

platforms types are mainly used for

television and radio: Fixed Service

Satellite (FSS), and Direct Broadcast

Satellite (DBS).

FSS

FSS are normally used for broadcast

feeds to and from television networks

and local affiliate stations, business

television, videoconferencing, and

commercial telecommunications.

DBS is a term used to refer to satellite television broadcasts intended

for home reception.

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FSS use the C band (3.7 to 4.2 GHz), and the lower portions of the

Ku bands (11.7 to 12.5 GHz). DBS use only a portion of the Ku band

(11.7 GHz to 12.7 GHz).

FSS

The world's first commercial satellite systems used the "C" band

frequency range. But the amount of power that any C-band satellite

could transmit has to be limited to a level that would not cause

interference to terrestrial microwave links.

The first commercial "Ku" band satellites made their appearance in

the late 1970s and early 1980s. Relatively few terrestrial

communications networks were assigned to use this frequency band;

Ku-band satellites therefore could transmit higher-powered signals

than their C-band counterparts

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ETS 300 421: STANDARD DVB-S

Describes the modulation and channel coding system for satellite

digital multi-programme Television (TV)/High Definition Television

(HDTV) services to be used for primary and secondary distribution in

Fixed Satellite Service and Broadcast Satellite Service bands.

Most digital satellite TV broadcasters today are using DVB-S

standard. It was first published in January 1995 by the European

Telecommunication Standards Institute (ETSI).

What makes the DVB standard a significant development is its ability

to serve as a unified standard that can be applied across a variety of

distribution platforms.

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ETS 300 421: STANDARD DVB-S

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ETS 300 421: STANDARD DVB-S

DVB-S performance against interference

RECEPTION OK

YES

NO C/N > C/N threshold

C/I > C/I threshold

BER < BER thresholdNO RECEPTION

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TRANSPONDER USED IN THE EXPERIMENTS

• Satellite Hispasat 1D

• Free to Air Channel

• Center Frequency 11.884 GHz

• Band Width 36 MHz

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TV-Ro STATION

IRD

TVLNB

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EXPERIMENTS

SET

SPECTRUM

ANALYZER

IRD

TVLNB

SIGNAL GENERATOR

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INTERFERENCE

SIGNAL

SPECTRUM

ANALYZER

IRD

TVLNB

SIGNAL GENERATOR

• Single carrier,

channel frequency

center.

• Carrier swept

inside the channel

BW.

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EXPERIMENT 1: C/I

RESULTS

C/I

C/I

MEASURE

C/I

THEORY

MIN 17.8 16.6

MAX 20.6 22.2

AVERAGE 19.2

C/I = C/N +12.2 (dB)

C/N min (C/N threshold)

C/N max (minimum loss)

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EXPERIMENT 2: BERRESULTS

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EXPERIMENT 3: Periodic or burst signal ?

RESULTS

tout

tin

tout

tin2. Burst signal

1. Periodic signal

BWsalto= BW3dB_canal DVB-S

BWsalto< BW3dB_canal DVB-S

BER1 = BER2

worst case

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CONCLUSIONS

In all experiment the results were

consistent with those expected.

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Thanks!