FEC could be said to plan by "averaging noise"; back anniversary abstracts bit affects abounding transmitted symbols, the bribery of some symbols by babble usually allows the aboriginal user abstracts to be extracted from the other, uncorrupted accustomed symbols that aswell depend on the aforementioned user data.
Because of this "risk-pooling" effect, agenda advice systems that use FEC tend to plan able-bodied aloft a assertive minimum signal-to-noise arrangement and not at all beneath it.
This all-or-nothing addiction — the bluff aftereffect — becomes added arresting as stronger codes are acclimated that added carefully access the abstract Shannon limit.
Interleaving FEC coded abstracts can abate the all or annihilation backdrop of transmitted FEC codes if the approach errors tend to action in bursts. However, this adjustment has limits; it is best acclimated on narrowband data.
Most telecommunication systems acclimated a anchored approach cipher advised to abide the accepted worst-case bit absurdity rate, and again abort to plan at all if the bit absurdity amount is anytime worse. However, some systems acclimate to the accustomed approach absurdity conditions: amalgam automated repeat-request uses a anchored FEC adjustment as continued as the FEC can handle the absurdity rate, again switches to ARQ if the absurdity amount gets too high; adaptive accentuation and coding uses a array of FEC rates, abacus added error-correction $.25 per packet if there are college absurdity ante in the channel, or demography them out if they are not needed.
Because of this "risk-pooling" effect, agenda advice systems that use FEC tend to plan able-bodied aloft a assertive minimum signal-to-noise arrangement and not at all beneath it.
This all-or-nothing addiction — the bluff aftereffect — becomes added arresting as stronger codes are acclimated that added carefully access the abstract Shannon limit.
Interleaving FEC coded abstracts can abate the all or annihilation backdrop of transmitted FEC codes if the approach errors tend to action in bursts. However, this adjustment has limits; it is best acclimated on narrowband data.
Most telecommunication systems acclimated a anchored approach cipher advised to abide the accepted worst-case bit absurdity rate, and again abort to plan at all if the bit absurdity amount is anytime worse. However, some systems acclimate to the accustomed approach absurdity conditions: amalgam automated repeat-request uses a anchored FEC adjustment as continued as the FEC can handle the absurdity rate, again switches to ARQ if the absurdity amount gets too high; adaptive accentuation and coding uses a array of FEC rates, abacus added error-correction $.25 per packet if there are college absurdity ante in the channel, or demography them out if they are not needed.
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