Optimization of Binary LDPC Codes for the q-ary Symmetric Channel with Moderate q

Gottfried Lechner (1) , Claudio Weidmann (1)

1 FTW - Telecommunications Research Center Vienna [Autriche]

We study the optimization of binary LDPC codes for the q-ary symmetric channel with moderate alphabet sizes q. For q = 2^m, a coding scheme can be viewed as a front-end mapping q-ary symbols to groups of m bits connected to a binary code. We derive a factor graph representation of the front-end and show that it can be processed with a complexity linear in m, the number of bits per symbol. We perform an extrinsic information transfer chart analysis and use it for code optimization.

Domaines: Théorie de l'information [cs.IT]; Théorie de l'information et codage [math.IT]

Gottfried Lechner, Claudio Weidmann. Optimization of Binary LDPC Codes for the q-ary Symmetric Channel with Moderate q. 5th International Symposium on Turbo Codes and Related Topics, Sep 2008, Lausanne, Switzerland. pp. 221 - 224, ⟨10.1109/TURBOCODING.2008.4658701⟩. ⟨hal-00789153⟩