Time-Reversal Diversity in Decision Feedback Equalization
Jaiganesh Balakrishnan and C. Richard Johnson, Jr.
Abstract
This paper considers the use of a time-reversal decision feedback
equalizer (DFE) in conjunction with a conventional DFE for block
processing of the received signal. A receiver structure that combines
the conventional DFE outputs and the time-reversal DFE outputs is
proposed. An optimal combining scheme of the two streams that
minimizes the mean-squared error (MSE) at the receiver output is
derived. The inherent diversity between the soft outputs of the two
streams is described and quantified under a few simplifying
assumptions. For the special case of a symmetric channel, the optimal
DFE filter setting that minimizes the MSE at the output of the
diversity combining block is derived. Simulation results demonstrating
performance gains for the proposed receiver structure are presented
for both symmetric and asymmetric channels.
