Abbreviations and Technical Terms
12 of 100
10
Abbreviations and Technical Terms
APID
(
Audio Packet Identifier
) Audio reception parameters in the MPEG data
stream
aBER
(
Bit Error Rate after Viterbi
) Ratio of the transmitted bits to the erroneous
bits after Reed Solomon (Viterbi)
BCH
(
Bose Chaudhuri Hocquenghem
) external error protection decoder
BER
(
Bit Error Rate
) The bit error rate shows the quality of the DVB signals. It
displays the number of erroneous bits in relation to all the transmitted bits.
bBER/CBER
(
Bit Error Rate before Viterbi
) Ratio of the received bits relative to bits that
have errors before Reed Solomon (Viterbi)
CBR
(Constant Bit Rate)
is used for MPTS measurements, cf.
VBR
C/N
(
Carrier to Noise
) Difference between the carrier signal and noise level in
dB; see also
S/N
EVM
(
Error Vector Magnitude
) Measures deviation of the transmitted symbols
to the ideal constellation, measured in dB.
FEC
Forward Error Correction (
Forward Error Correction
), e.g. in case of the
code rate ¾, ¾ of the information is user data, ¼ of the data come from
the Viterbi correction.
Guard Interval
Guard interval by extending the symbol through a gap. Due to this, good
reception is possible even in case of strong reflections.
LCN
(
Logical Channel Numbering
) Logical channel sorting performed by the
provider
LDPC
(
Low Density Parity Check
) A new error protection method applied in
DBV-S2 (Gallager codes). Inner error protection; code rates from ½ to
9
/
10
MER
MER (
Modulation Error Rate
) is the ratio of the average signal power to
the average error power in dB. It is a kind of a C/N measurement which
gives information whether the receiver is able to demodulate the received
signal.
MPTS
Multiple Program Transport Stream
NID
(
Network Identification
) Network ID or channel identification number
between 0 and 8191
NIT
(
Network Information Table
) contains, for example, information about all
available transponders, PIDs, downlink frequency, polarisation, next tran-
sponder for the scan; transmitted in the multiplexer transport stream
Содержание MSK 130
Страница 99: ...99 of 100 ...