An Efficient Soft-Input Scaling Scheme for Turbo Decoding

As the number of iterations increases, the soft inputs and outputs of a turbo decoder gradually become more reliable. To take the effect into account, this paper presents an efficient adaptive scaling scheme for turbo decoding that extends the sign difference ratio (SDR) technique. Unlike the conventional approach using a fixed set of scaling factors, it adaptively determines the scaling factor for each data block. Simulation results show that the proposed scaling scheme can reduce up to frac14~frac12 iteration when compared to the existing stopping criteria while achieving 0.1~0.2 dB coding gain improvement on average