Weight spectrum evaluation for multi-binary tailbiting turbo codes

In this paper we propose a method for the evaluation of the weight spectrum of parallel concatenated turbo codes with tailbiting (circular) m-ary component codes. Our method is based on a two step evaluation; we search and store a set of error events for the component codes; then, we evaluate the spectrum of the concatenated code with the actual interleaver. When working with different interleavers, the first step is computed only once. We show some examples with rate 6/7 component codes.