In digital radio transmission over frequency selective channels, the Minimum Mean-Square Error Decision Feedback Equalizer (MMSE-DFE) is widely recognized as an efficient equalization scheme. In order to compute the coefficients of the feedforward and feedback filters of the MMSE-DFE, both the channel impulse response (CIR) and the variance of the noise have to be estimated. The estimate of the...

The bidirectional decision feedback equalizer (BiDFE) that combines the outputs of a conventional decision feedback equalizer (DFE) and backward DFE can improve the performance of the conventional DFE by up to 1-2 dB based on simulations. In this letter, the BiDFE concept is extended to multichannel time reversal communications involving a DFE as a post-processor. Experimental data collected in...

A novel version of the reduced-state Bayesian Maximum A Posteriori Probability /Decision-Feedback (MAP/DF) equalizer for ISI channels with long impulse responses is presented. The main feature of the proposed equalizer is that the soft-statistics generated by the MAP receiver are employed to recursively compute a suitable index of the actual reliability of the (soft) decisions feeding the DF fi...

In this paper, the idea of multi-split adaptive filtering is applied on DFE. The feed-forward and feedback sections in the DFE are divided into parallel sub-filters by imposing separately the symmetry and antisymmetry conditions on the impulse responses of filters by using appropriate and distinct sets of linear constraints. The purpose of this is to obtain a new structure that gives better per...

Orthogonal frequency division multiplexing (OFDM) is one of the modulation scheme, used for high speed mobile communication. However, fast time varying multipath channels leads to loss of orthogonality of subcarriers and introduces inter carrier interference (ICI). In this study, MMSE equalizer is implemented to remove ICI. The information of Channel Impulse Response (CIR) required for equalize...

The Non-Causal Decision-Feedback Equalizer (NCDFE) is a decision-aided equalizer that uses not only past decisions, like DFEs, but also future decisions, which usually come from another, classical equalizer. When there are no errors on the decisions, the NCDFE attains the Matched Filter bound (MFB). In practice, it suffers from the propagation of errors. We propose an implementation of the NCDF...

This paper brings some noticeable improvements to a blind decison feedback equalizer recently introduced and mainly characterized by its self-adapted structure. In its starting-up mode, this equalizer is linear and recursive and controlled by a whitening criterion for the recursive part and the Godard criterion for the transversal one. However, in the case of high order QAM signals, the whole p...