PRECODING METHOD IN RAPTOR CODE BASED ON B-J CODE

摘要

On the basis of the introduction of the LT Code, analyzed its disadvantage, and then introduce the Raptor Code. By using precoding method, the Raptor Code can overcome the deficiency that time and space overhead is not fixed in the LT Code. It puts forward improving method based on LT Code through the analysis of the single or multiple levels precoding method and precoding method based on B-J code. We employ a class of B-J codes with dimension 2 as base code and obtain a new class of LDPC code by using q-tuples to substitute the elements of ( ) GF q . The improving method has many advantages such as high decoding rate, flexibility in choices of the code length and rate of Raptor Code.