Joint Blind Equalization and Decoding over Frequency Selective Channels in OFDM Systems Using Particle Filtering Joint Blind Equalization and Decoding over Frequency Selective Channels in OFDM Systems Using Particle Filtering
Subject Areas : electrical and computer engineeringN. Ghasemi 1 , M. F. Sabahi 2 * , A. R. Forouzan 3
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Keywords: OFDM blind equalization joint equalization and decoding particle filtering,
Abstract :
In this paper a sequential algorithm is proposed for joint blind channel equalization and decoding for orthogonal frequency-division multiplexing (OFDM) in frequency selective channels. This algorithm offers a recursive method to sequentially calculate the posterior probability for maximum a posteriori (MAP) detection. Recursive calculations are done along the indexes in each OFDM symbol using a particle filter. By defining an appropriate importance function, and a proper prior probability distribution function for the channel tap coefficients (and marginalizing it), an efficient method is presented for joint equalization and channel decoding in OFDM based systems. Performance of the proposed detector is evaluated using computer simulations and its bit error rate is compared with the trained turbo equalizer and a conventional particle filter-based method. The results show that the proposed method outperforms the previously presented particle filter-based method without a need for training data.
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