On the free distance of LDPC convolutional codes
Arvind Sridharan, Dmitri V. Truhachev, Michael Lentmaier, Daniel J. Costello, Kamil Sh. Zigangirov · 2004
A lower bound on the free distance of LDPC convolutional codes defined by syndrome former matrices comprised of MtimesM permutation matrices is derived. We show that asymptotically, i.e., as Mrarrinfin, for almost all codes in the ensemble the free distance grows linearly with constraint length