Suitable mobile channel conditions for a concatenated coding system with list-of-2 Viterbi inner decoder
Usana Tuntoolavest, Pongpisut Noradee · 2010
List-of-2 Viterbi decoder provides two decoded outputs for each input sequence. The two outputs are the one with the highest likelihood value and the one with the second highest likelihood value. Previous work proposed this decoder as the inner decoder of a concatenated coding system with Vector Symbol Decoder (VSD) as the outer decoder. Since both outputs of the inner decoder are to be input to VSD, the error statistics of both outputs are of interest. This paper investigates the error statistics in mobile channels using the models of Rayleigh fading and Ricean fading channels with Doppler shifts. Results show that this inner decoder provides useful output error statistics for VSD for some particular mobile channel conditions. By selecting appropriate criteria for these statistics, the suitable SNR ranges can be concluded for this concatenated coding system for various channel models. For example, for Rayleigh fading channel with the speed of 120 km/h, the SNR range of interest is 8.1-9.8 dB. For Ricean fading channel with the speed of 60 km/h and Ricean factor of 10, this range is 6.4-8.1 dB. This information is useful for the application of this coding system to mobile communications.