Chapter 7 - TV Measuring Range
71
106 V3.2
Further DVB-T2 parameters
7.2.2.4.4
The
PARAMETERS
menu item can be used to display a window in which additional DVB-T2
parameters are listed.
Figure 7-18 DVB-T2 parameters info
Explanations:
•
Pilot Pattern = PP4
•
PAPR = OFF (“Peak to Average Power Reduction = OFF”) – Crest factor reduction off
•
LDPC-Frame = Normal length
•
ROT = OFF (Constellation rotation off)
•
Cell_ID = cell of the transmitter
•
System = SISO (Single In Single Out) – One transmission antenna and one receiving
antenna, as opposed to MISO which has two transmission antennas and a receiving antenna.
•
PLPs: Physical Layer Pipes, more services in one channel maybe with different modulation.
•
PLP_ID: Index of the chosen PLP
•
V=1.3.1 active DVB-T2-Version
•
Post_Scrambeled: from Version 1.3.1 and higher additional coding.
•
Base_Lite: additional PLP at lower code rate
Selection of PLPs (Physical Layer Pipes)
7.2.2.4.5
Are more services (PLPs) in a channel available, they can be selected by the menu SET PLP.
Once a new PLP is selected, the corresponding lists are build and displayed.
BER measurement (Bit Error Rate)
7.2.2.4.6
The measurement of the bit error rate aids in the determination of the quality of a DVB-T2 signal.
To determine the bit error rate, the error correction mechanisms in the digital receiver are used.
The data stream is compared before and after correction and the number of corrected bits is
determined from that. This number is placed in a ration to the total throughput of bits and the BER
is calculated based on that.
For DVB-T2, two independent error protection mechanisms work together. LDPC (Low Density
Parity Check) is used for internal error protection, BCH (Bose Chaudhuri Hocquenghem) is used for
external error protection.
The equipment measures the bit error rates before LDPC (CBER) and after LDPC (LBER).