Partially Systematic Rate 1/2 Turbo Codes

Partially systematic parallel concatenated (turbo) codes of rate 1/2 are considered. These are generated from a classical rate 1/3 turbo code by puncturing both the parity bits and the systematic bits. The so-called “error-floors” of the resulting codes are lower than those of their systematic counterparts. For some puncturing patterns, even the “waterfall region” is shifted to lower signal-to-noise ratios. Hence, the performance of rate 1/2 turbo codes can be enhanced by simply spreading the puncturing over the parity and the systematic bits without increasing encoding and decoding complexity.