Performance of Turbo-Codes on Nakagami Flat Fading (Radio) Transmission Channels

In this paper, we analyze the performance in terms of bit error rate and frame error rate of a turbo-coded system over Nakagami frequency-nonselective (flat) fading multipaths channels. First, an efficient method to generate uncorrelated Nakagami-m fading samples is proposed. Through the parameter m, the Nakagami distribution accurately model signal fading conditions that range from severe to moderate. The primary justification for the use of the Nakagami-m distribution is its good fit to empirical fading data. Second, we modify calculation of the channel log likelihood ratios at the input of the decoder in order to take into account the Nakagami distribution of the channel fading. The simulation results show that turbo-codes provide tremendous gain over uncoded transmission in presence of Nakagami fading