Digital Signal Processing Reference
In-Depth Information
15 DVBS Measuring Technology
15.1 Introduction
The satellite transmission of digital TV signals has now been discussed in
detail. The following sections will deal with DVB-S measuring technol-
ogy. The DVB Measurement Guidelines ETR290 also contain a relatively
small chapter on DVB-S measuring technology. In comparison with DVB-
C and DVB-T measuring technology, the discussion will be relatively brief
here. Satellite transmission is relatively rugged and, in principle, only sub-
ject to noise effects (approx. 205 dB free space attenuation), and possible
irradiation due to microwave links.
For these reasons, the essential tests parameters on a DVB-S signal are:
•
Signal level
•
C/N (carrier/noise ratio)
•
Bit error ratio
•
Shoulder attenuation
The following is required for measurements on DVB-S signals:
•
A modern spectrum analyzer (e.g. Rohde&Schwarz FSP, FSU)
•
A professional DVB-S receiver with BER measurement
•
A DVB-S test transmitter for measurements on set-top boxes and
IDTV receivers (e.g. Rohde&Schwarz SFQ, SFU, SFL)
15.2 Measuring Bit Error Ratios
Due to the inner and outer error protection, there are three bit error ratios
in DVB-S:
•
Pre-Viterbi bit error ratio
Search WWH ::
Custom Search