Decoding Codes on Graphs
نویسندگان
چکیده
Iterat ive decoding is a widely used technique in modern communications systems. The Low Density Parity Check (LDPC) codes of Gallager were the earliest codes for which iterat ive decoding techniques were dēned. These codes along with a simple iterat ive decoding algorithm were int roduced in the r̄st part of this art icle. Here we describe a probabilist ic iterat ive decoding scheme, also proposed by Gallager, and show how many modern iterative decoding algorithms are derived from his basic scheme.
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6.962: Week 4 Summary of Discussion Topic: Codes on Graphs 1 a Brief History of Codes on Graphs
1962 Gallager invents low density parity-check LDPC codes 1112 and what is now known as the sum-product iterative decoding algorithm for a p osteriori probability APP decoding. 1981 Tanner founds the eld of codes on graphs, introducing the bipartite graphical model now widely popular referred to as a Tanner graph" and the decoding algorithm now called the min-sum" or max-product" algorithm. Tan...
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