A block adaptive DFE in the frequency domain based on tentative decisions

In this paper a new block adaptive DFE implemented in the frequency domain is derived. The new algorithm is suitable for rejecting ISI due to multipath echoes, especially to wireless transmission systems which involve channels with long impulse response. The novel idea is to use tentative decisions properly derived by minimizing a frequency domain criterion. The algorithm has a steady-state performance which is practically identical to that of the symbol-by-symbol DFE. At the same time it offers a faster convergence rate and substantial savings in complexity. Additionally, the level of the steady-state MSE achieved by the algorithm is insensitive to the length of the block. Thus the new algorithm allows a trade off between complexity and processing delay without affecting performance.