Girth Properties of Time-Varying SC-LDPC Convolutional Codes
Massimo Battaglioni, Marco Baldi, Franco Chiaraluce, Michael Lentmaier · 2019
Time-varying spatially-coupled low-density parity-check convolutional codes (SC-LDPC-CCs) exhibit excellent features, but their representation requires a very large number of parameters. On the other hand, the description of time-invariant SC-LDPC-CCs is very convenient and their error rate performance, though usually worse, is often satisfactory. In this paper we investigate the girth properties of these codes, showing that the time-invariant ones have some weaknesses, which can be compensated by introducing a small periodicity in the code. By considering periodically time-varying codes, we achieve considerable improvements in the girth properties using few more degrees of freedom with respect to the time-invariant case.