Turbo Equalization for Unknown Channels: A Semi-Blind Approach

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, even for long ISI channels. Furthermore, the semi-blind approach leads to an improved bit error rate performance and a decrease in the overall computational burden when compared with full blind schemes. The reduction in computational complexity increases with the ISI channel length.