Improved union bounds on turbo codes performance in the Rician fading channel

In this work, an improved union bound on the performance of turbo codes is evaluated using a new union bound presented by Viterbi et al., (1998). The characterization of turbo code performance is provided considering both the fully-interleaved channel and correlated Rice slow-fading channel. A uniform interleaver is assumed: this strategy allows one to derive the average performance of the turbo coding scheme by analysis. Of interest is the improvement of the bound for values of E _b/N₀ near and below R₀ (i.e., the “computational cutoff rate”), region where the conventional union bound becomes useless. This improvement allows a better estimate of the code performance in conjunction with the AWGN channel and with the fast-fading fully-interleaved channel. Moreover, it allows one to determine a tighter bound to the actual code performance as far as the slow fading Rician channel is concerned