Multiple Independent Interferences Cancellation for SC-FDE Systems Using Widely Linear Iterative Equalizers

On the Impact of the Number of Interferers and Channel Estimation Errors in SC-FDE SIMO IB-DFE Systems

“…With this, we have to C sŝ = Cŝŝ = Cŝ s = σ 2 s I N , C rŝ = C rs and Cŝ r = C sr . Thus, by imposing the constraint that the feedback filter removes the ISI but not the desired symbol, by minimizing the MSE expressed by (8) we obtain the coefficients of the filters A l and B l , which are given by [10]:…”

“…With this, immediately after the first iteration the feedforward filter is switched to the matched filter. Note that the difference between the equalizer that takes into account the channel estimation errors and the one presented in [10] is the presence of the channel estimation error variances σ 2 e and σ 2 ie in (9). If both are equal to zero, we have the conventional SIMO IB-DFE equalizer seen in [10], i.e., H e = H ie = 0 N .…”

“…Note that the difference between the equalizer that takes into account the channel estimation errors and the one presented in [10] is the presence of the channel estimation error variances σ 2 e and σ 2 ie in (9). If both are equal to zero, we have the conventional SIMO IB-DFE equalizer seen in [10], i.e., H e = H ie = 0 N . Furthermore, if we only had one iteration (l = 0), the feedback filter is zero due to the lack of previous decisions A l is also reduced to A l = C −1 rr C rs , that is, the conventional MMSE equalizer [11].…”

Study of Widely Linear SC-FDE Systems for Interference Cancellation

“…It was found out that it has a better error performance and a higher robustness to channel estimation errors when compared to the SL version. Finally in [20] and [21], the authors proposed a WL-MMSE and WL-IB-DFE equalizer respectively for a SC-FDE system under the effect of up to K known interferences. It was seen that the system becomes more robust in terms of BER applying the widely linear equalizers with respect to its SL versions.…”

“…The goal of the present work is to develop analytical expressions for the MSE for the widely linear equalizers presented in [20], [21] in order to obtain the signal-tointerference-plus-noise ratio (SINR) and consequently the analytical BER for the MMSE and IB-DFE equalizers in their strictly and widely linear versions. Results obtained with these expressions were verified and analyzed with respect to the simulation results and the behavior of the system when the number of interferences grows respectively.…”