Interleaver design for turbo codes based on the performance of iterative decoding

The performance of a turbo code is dependent on two properties of the code: its distance spectrum and its suitability to be iteratively decoded. Both these properties are dependent on the specific interleaver used in the turbo-coding scheme. This paper describes a strategy for interleaver design that includes a criterion for the performance of iterative decoding. This criterion is based upon correlation properties of the extrinsic information, which is used as a priori inputs to the constituent decoders. Simulations comparing interleaver choices indicate an improved turbo code performance for interleavers designed with algorithms including a correlation criterion