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R. Nissel, M. Rupp:
"Doubly-Selective MMSE Channel Estimation and ICI Mitigation for OFDM Systems";
Talk: IEEE International Conference on Communications (ICC2015), London, UK; 06-08-2015 - 06-12-2015; in: "IEEE International Conference on Communications (ICC2015)", (2015), 6295 - 6300.

In high mobility Orthogonal Frequency Division Multiplexing (OFDM) systems, subcarriers are no longer orthogonal, causing Inter-Carrier Interference (ICI). Equalization then becomes more challenging and requires an accurate estimate of the time-variant channel. In this paper, we propose a novel Minimum Mean Squared Error (MMSE) estimation of the sampled time-variant transfer function. Based on such channel estimation, we propose an iterative three step ICI mitigation technique. In Step 1, we consider ICI as an additional noise term. In Step 2, we reduce the ICI at pilot positions and finally, in Step 3, we treat all estimated data symbols, obtained from Step 2, as if they were pilot symbols. We evaluate the Bit Error Ratio (BER) of our ICI mitigation technique by means of simulation and testbed measurements (up to 400 km/h). In both cases, we achieve a BER close to perfect channel knowledge and zero ICI.

OFDM; inter-carrier interference; ICI; time-varying channels; doubly-selective channels; fast fading; channel estimation; MMSE; ICI mitigation; bit error probability; LTE; testbed; measurement

http://publik.tuwien.ac.at/files/PubDat_239157.pdf

Project Head Christoph Mecklenbräuker:
Christian Doppler Lab "Funktechnologien für nachhaltige Mobilität"