A new multipath channel transformation technique

Authors: TUĞRUL ÇAVDAR

Abstract: A new channel transformation technique is introduced in this paper The technique is employed on the receiver side and has 2 filters. The first filter is the inverse complex conjugate of the estimated channel. The profile of this filter's output is triangular. The taps of the second filter are calculated according to the output of the first filter to produce an exponentially decreasing profile. This technique transforms most channel profiles to exponentially decreasing channel profiles. Thus equalizers adopting the proposed technique may have better bit error rates and lower computational complexity on frequency-selective channels. This paper evaluates the efficiency of the proposed technique on a sequential channel equalizer in different channel conditions and modulations to compare the results with others reported in the literature. Computational complexity and bit error rates under different circumstances are provided. The channel transformation technique exhibits performance levels close to the optimum results of the Viterbi algorithm and proves to be a usefultool for equalizers.

Keywords: Channel transformation, sequential decoding, frequency-selective channel, equalization

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