Comunicació presentada en el International Symposium on Information Theory (ISIT '08), celebrat els dies 6, 7, 8, 9, 10 i 11 de juliol de 2008 a Toronto (Ontario, Canadà), organitzat per Institute of Electrical and Electronics Engineers (IEEE).

A new graph-based construction of generalized low density codes (GLD-Tanner) with binary BCH constituents is described. The proposed family of GLD codes is optimal on block erasure channels and quasi-optimal on block fading channels. Optimality is considered in the outage probability sense. A/nclassical GLD code for ergodic channels (e.g., the AWGN channel,/nthe i.i.d. Rayleigh fading channel, and the i.i.d. binary erasure channel) is built by connecting bitnodes and subcode nodes via a unique random edge permutation. In the proposed construction of full-diversity GLD codes (referred to as root GLD), bitnodes are divided into 4 classes, subcodes are divided into 2 classes, and finally both sides of the Tanner graph are linked via 4 random edge permutations. The study focuses on non-ergodic channels with two states and can be easily extended to channels with 3 states or more.

The work of Ezio Biglieri was supported by the STREP project "DA/nVINCI" within the 7th FP of the European Commission.