Construction of Turbo Code Interleavers from 3-Regular Hamiltonian   Graphs
  In this letter we present a new construction of interleavers for turbo codes from 3-regular Hamiltonian graphs. The interleavers can be generated using a few parameters, which can be selected in such a way that the girth of the interleaver graph (IG) becomes large, inducing a high summary distance. The size of the search space for these parameters is derived. The proposed interleavers themselves work as their de-interleavers. 
Arya Mazumdar, A K Chaturvedi, Adrish Banerjee