2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/136245The performance of codes defined from graphs depends on the expansion property of the underlying graph in a crucial way. Graph products, such as the zig-zag product and replacement product provide new infinite families of constant degree expander graphs. The paper investigates the use of zig-zag and replacement product graphs for the construction of codes on graphs. A modification of the zig-zag product is also introduced, which can operate on two unbalanced biregular bipartite graphs.Submitted to Journal of Advances in Mathematics of Communications, Aug. 2007Information Theorytext