Explained: Gallager codes
Jan 21
In those predigital days, communications channels — such as phone lines or radio bands — were particularly susceptible to the electrical or electromagnetic disruptions known as “noise.” Shannon proved the counterintuitive result that no matter how noisy a channel, information could be sent over it error free. All you needed was a way to add enough redundancy to the information so that errors could be corrected. He also demonstrated that there was a hard limit on how efficient those error-correcting codes could be — a minimum amount of extra information that would guarantee near-zero error. Since longer codes take longer to send, a minimum code length implied a maximum transmission rate — the Shannon limit. Finally, Shannon proved that codes approaching that limit must exist. But he didn’t show how to find them.
Link:
http://web.mit.edu/newsoffice/…
Check out these posts too:
- Calculate the distance between two zip codes
- Retail Me Not: Coupon codes for online stores
- Codes for the Representation of Names of Languages
- JavaScript error reporting service with DamnIt
- YouTube upload limit increases to 15 minutes
- Did you have a problem installing Windows Defender?
- 10 Big Myths about copyright explained
Facebook
RSS
Twitter
Recent Comments