Finite length LT codes over Fq for unequal error protection with biased sampling of input nodes

摘要

Finite length LT codes over higher order Galois fields Fq for unequal error protection (UEP) are analysed under maximum likelihood (ML) decoding. We consider a biased sampling method to create the LT code graph. In contrast to a previous approach by Rahnavard et al., where a predetermined number of edges is created per importance class given a check node of degree d, our procedure allows to precisely adjust the desired class weights. Moreover, we provide upper and lower bounds on the symbol erasure probability for each importance class.