User's Manual

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Code Rate
The code rate represents the amount of Forward Error Correction (FEC) used for each active symbol. FEC is
a method of obtaining error control in data transmission. A code rate of ½ means that for two bits of
information received, 1 bit is the real data. The other bit tells how intact the first bit is. A code rate of 7/8
means that out of the 8 bits sent, there are 7 bits of real data and only 1 bit that is to catch any errors in those
7.
Transmission Rates
Finding the best transmission mode to suit a given situation means selecting the best compromise between
modulation, guard interval and code rate. What follows are the ETSI EN 300 744 V1.4.1 (2001-01) standards
for the useful bitrate (Mbit/s) for all combinations of guard interval, constellation and code rate for non-
hierarchical systems for 6, 7, and 8 MHz channels respectively.