Semi-blind combined detection and turbo decoding for unknown block fading channels

We present a semi-blind approach to combined detection and turbo decoding for unknown ISI channels. The proposed method utilizes very few training symbols and minimizes the probability of ill-convergence characteristic of full-blind approaches. The suitability of the proposed semi-blind scheme for a delay constrained wireless communication system, where the ISI channel is modeled as a frequency selective block fading channel, is investigated. Simulation results show that, even considering short frame lengths, the semi-blind scheme presents good performance over such slowly time-varying environments.