Estimating the minimum distance of large-block turbo codes using the event impulse method

This paper describes the application of an iterative technique referred to as the event impulse method (EVIM) to estimating the minimum distances of large-block turbo codes with 4-, 8- and 16-state binary constituent codes. The EVIM is specifically tailored to handle long interleavers with high spread. It is shown that the reliability of the EVIM is similar to that of a previous iterative triple impulse method (TIM), but the complexity is much lower. Minimum distances of 38, 60 and 92 have been obtained (estimated) for rate 1/3 turbo codes with 4-, 8- and 16-state constituent codes, respectively, using dithered relative prime (DRP) interleavers of length K=16384.