Promax HD Ranger +, Руководство пользователя

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December 2014
7
A1.1.4
Digital SATELLITE television signal of SECOND generation
(DVB-S2 standard/QPSK/8PSK modulation)
DVB-S2 Parameters
►
Channel Bandwidth
It displays the channel bandwidth from 1.3 MHz to 60.75 MHz.
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Spectral inversion
It detects if the input signal has been inverted.
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Symbol Rate
It represents the number of times the signal status changes in a period of
time. The bandwidth is related to this parameter.
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Roll-Off Factor
Roll-off factor of Nyquist filter. It indicates the excess of bandwidth over
the ideal bandwidth.
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Constellation
QPSK or 8PSK modulation for DVB-S2 signal constellation.
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Code rate
It defines the ratio between the number of data bits and the total number
of bits transmitted (the difference corresponds to the number of control
bits for the error detection and recovery).
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PLP id
It is the PLP identifier. In the case of PLP Single mode identifies the input
stream (0-255). In the case of PLP Multiple mode clients can choose the
PLP ID to view.
DVB-S2 Measurements
Power
Measured power over the entire bandwidth of the channel.
C/N
Carrier/Noise ratio where C is the received power of the modulated carrier
signal and N is the noise power received. To measure it correctly the
channel should be tuned at its centre frequency.