A low complexity approach to equalization for doubly selective channels

In this manuscript, a low complexity scheme for linear and decision feedback equalization of doubly selective channels is introduced, and it is further extended to low complexity turbo equalization of doubly selective channels. The proposed low complexity scheme involves time-varying equalizer design by explicitly solving for the equalizer at a few sparse points within the transmit block. The obtained equalizer coefficients at these uniformly spaced points within the transmit block are then interpolated to obtain the equalizer coefficients in the remainder of the block. This interpolation-based approach to time-varying equalizer design ensures a low design complexity. The performance of the proposed low complexity equalizer is assessed through numerical simulations. Furthermore, its effectiveness in a turbo equalization setup is studied by numerical simulations, which show the effectiveness of the proposed algorithm.