This article presents a simple approach for the equalization of a nonlinear time varying communication channel using a quasi type-2 fuzzy system. Basically, the Quasi-type 2 fuzzy equalizer is tuned by clustering the output of the channel as it is proposed in previous reported works for other fuzzy equalizers. The main difference is that the quasi type-2 fuzzy perspective permits to derive more design parameters from clustering. The proposed equalizer is compared with type one and interval type-2 equalizers. Although, simulation results show that the quasi type-2 fuzzy adaptive filter exhibits better performance for particular levels of uncertainty, it behaves similarly to the other equalizers in general terms.

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This paper presents a proposal for channel equalization of non-linear time varying communication channels that uses strategies based on quasi type-2 fuzzy sets. Both triangular and trapezoidal quasi type-2 fuzzy equalizers are designed by means of an incremental design approach. A comparative experimental study among several fuzzy equalization architectures is carried out, showing that the equalizer based on trapezoidal quasi type-2 fuzzy sets exhibits the best performance for low and medium levels of uncertainty. The results of this work also suggest that high order fuzzy sets make the equalization process more robust to the variability of the communications channel.