Performances of turbo codes with fading compensation in multipath channels

This paper studies the performance of a turbo-coded system in the frequency non-selective correlated Rayleigh fading channels. The turbo-coded system employs a pilot-symbol-aided (PSA) technique for fading compensation and interleaving for spreading the error bursts to reduce the error rate. The PSA technique is also used to provide the decoder with channel side information (CSI) for better performance in fading channel. Two PSA techniques, three normalized Doppler spreads and different interleaving sizes have been investigated. Results of computer simulations have shown that, an improved first-order fading prediction technique can improve the BER performance by a factor of about 62, relative to those obtained using the pilot symbols only. Results have also shown that an interleaving depth equal to one-quarter the reciprocal of normalized Doppler spread can achieve a good BER performance