O'Reilly logo

Direct Broadcast Satellite Communications: An MPEG Enabled Service by Donald C. Mead

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

Chapter Five Forward Error Correction

All digital communication systems suffer from errors. An error is made if a transmitted 0 is decoded as a 1, or vice versa. DBS systems are particularly vulnerable to transmission errors because they are distributing highly compressed files. Thus, the effect of a bit error can be very large.

5.1 What Is Error Correction?

To combat bit errors, a number of techniques have been developed, including forward error correction (FEC). Consider Table 5.1a. The column to the right of the vertical line is a parity on the bits to the left of it. The value is a 1 if there is an odd number of Is, and a 0 if there is an even number of 1s. Likewise, the bits below the horizontal line are parity bits on the columns. The ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required