Concatenated codes based on multidimensional parity-check codes and turbo codes

Turbo-codes provide communications near capacity when very large interleavers (and thus codeword lengths) are used. However, many military communication systems require packet lengths that are too short to exploit the full capability of these codes. We have previously shown that a rectangular parity-check code can be used as an outer code with a turbo code as an inner code in a serial concatenated coding scheme, and that this configuration significantly lowers the error floor and improves performance for packets of only a few thousand bits. In this research, we show that for short packets, the performance can be further improved by replacing the rectangular parity-check code by a multidimensional parity-check code that operates at a higher rate and has a higher minimum distance than the rectangular parity-check code. The new codes makes it possible to achieve very low error probabilities with even simple turbo codes and without the use of complicated interleaving schemes.