Estimating the minimum distance of turbo-codes using double and triple impulse methods

A long-standing problem for turbo-codes has been the efficient and accurate determination of the distance spectrum, or even just the minimum distance, for specific interleavers. This letter compares a number of distance estimation techniques and introduces two new approaches based on iterative processing. The new approaches are more reliable and are particularly useful for long blocks with high minimum distances. Distance measurement results are presented for random, high-spread random (HSR) and dithered relative prime (DRP) interleavers.