MMSE equalization for bandwidth-efficient multicarrier systems

Multicarrier systems, used in many of today´s communications standards like 802.11b, are very prominent candidates for future mobile communication systems. Complex modulated transmultiplexer filter banks (Tzannes et al., 1994) providing improved frequency responses in comparison to orthogonal frequency division multiplex (OFDM) are proposed without a cyclic prefix. For the sake of increased bandwidth efficiency, they require an equalizer which mitigates the distortion of the frequency selective transmission channel. An efficient implementation of these transmultiplexer filter banks leads to discrete Fourier transformation (DFT) transmultiplexer filter banks. The advantages of such modifications with respect to OFDM are discussed and the results for the design of the required channel equalizer are presented