Alcad DM-102, Техническая записка

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11
FEC (forward error correction) has 5 option rates. All broadcast systems transmitting data will
suffer errors. In order to correct these errors various forms of error correction are used. The
rate at which this is done affects the rate at which the data can be transmitted. The higher the
level of error correction that is applied, the greater the level of supporting error correction data
that is needed in order to be transmitted.
In turn this reduces the data rate of the transmission. Accordingly it is necessary to match the
forward error correction level to the requirements of the broadcast network. The error
correction uses Convolutional Coding and Reed Solomon with rates
of 1/2, 2/3, 3/4, 5/6 , and
7/8 dependent upon the requirements.
Press transmit button on the programmer to send the change through to module.
Guard Interval has 4 different interval rates 1/32, 1/16, 1/8 and 1/4. Guard Intervals are used to
ensure that individual transmissions do not interfere with each other. In COFDM systems the
beginning of each symbol is preceded by a guard interval. As long as the echoes fall within this
interval they will not affect the receiver’s ability to safely decode the actual data. We generally
recommend using
1/16 .
Press transmit button on the programmer to send the change through to module.
Cell ID is a unique number that is used to identify the transmission from base station tower.
Press transmit button on the programmer to send the change through to module.
We now come to the services section of the programmer. Please look below at the screenshot
below.