1/2 FEC means half the data is error correction. A higher FEC of 7/8 means 1/8 of data is error correction.
Source: Domestic Radio TV & Satellite Reception - Confederation of aerial industries by RA Calaz, MIEE, MSCTEE, ACGI 2002
An FEC of 2/3 equates to two thirds of the signal being data and one for error correction.
Source: wikipedia
3/4 FEC, for every 3 bits of data, you are sending out 4 bits, one of which is for error correction.
Source: Introduction to digital modulation -catv
An FEC system denoted as 3/4 implies that one extra Error Correction Bit is transmitted for every 3 data Bits. Similarly for a
<div>7/8 FEC, one Error Correction Bit is transmitted extra for every 7 Bits of data. As one can imagine, an FEC of
3/4 provides better correction and is less prone to error and noise than an FEC of 7/8. To that extent, an FEC
of 1/2 would be extremely robust since it would carry one correction Bit for every data Bit.
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