Joint Transmitter/Receiver Channel Equalization for Frequency-Domain Punctured Turbo Codes

This paper proposes a one-tap frequency-domain transmitter filtering method that assumes channel knowledge at the transmitter for turbo coded single-carrier transmission with our previously reported frequency-domain puncturing at the transmitter and turbo equalization at the receiver. In coded single carrier transmission in a frequency-selective fading channel, inter-symbol-interference (ISI) severely degrades the error rate at the receiver. Furthermore, frequency-domain puncturing causes additional ISI for the sake of increased number of coded bits to be transmitted. The proposed one-tap frequency-domain filtering method of the transmission signal at the transmitter reduces the ISI or increases the frequency diversity to increase the received signal power. In order to take into account the ISI reduction at the receiver due to turbo equalization, the proposed method is designed with the ISI level as a parameter. Simulation results show that by appropriately setting the ISI-level parameter according to the number of iterations in the turbo equalization, the proposed method reduces the error rate compared to the case without transmitter filtering. We also show the effectiveness of frequency-domain puncturing compared to the conventional time-domain puncturing with the number of receiver antennas as a parameter.