Performance comparison of frequency domain equalizers for the IEEE 802.16a WMAN standard

In this paper, due to the low computational complexity, the iterative block FD equalizer is considered. The performance of two new methods for the filter design with the objective of minimizing the MSE at the detector input is described and evaluated. In the first design method denoted Correlation-based design of IBDFE (C-IBDFE), the reliability of the detected data is measured. The second method denoted soft IBDFE (S-IBDFE) derives the data reliability directly from the equalizer output. The proposed schemes are evaluated both in terms of implementation complexity and in terms of bit error rate. Results are compared with the existing hybrid DFE (HDFE) where the FF (feedforward) filter is implemented in the FD. Performances of various DFEs are compared for an IEEE 802.16a WMAN transmission on the fixed wireless channels. By simulations on dispersive channels for IEEE 802.16a it is shown that the new structures outperform the HDFE, and have a lower complexity.