مقارنة أداء ترميزات تربو التلفيفية و الصندوقية و تحسينه

Turbo code is recommended as a channel coding scheme, which has been shown to be capable of performing close to the Shannon limit. In this paper, we compare the performance of both convoluted and block turbo codes over AWGN and Rayleigh fading channels. It has been observed that the performance of convoluted turbo code is slightly better in the rainfall region, and the coding gain ranges between 0.5 and 0.7 dB at BER ofdepending on the channel conditions. But below BER ofor an error floor occurs in the case of convoluted turbo code. When BER is low, Block turbo codes tend to outperform convoluted turbo codes. Then, we propose an optimal encoder for achieving the best error-floor performance in the case of convoluted turbo code. Finally, using the optimal encoder, we present a turbo code design, utilizing MATLAB and analyzing its performance.