Quasi-minimum-BER linear combiner equalizers

It is well known that the minimum mean square error (MMSE) and minimum peak distortion (MPD) criteria do not minimize bit error rate (MinBER), and for some channels they can have a large degradation compared to the MinBER solution. Based on the strengths and weaknesses of the MMSE and MPD criteria, we have defined two new solutions, which we call minimum noise limited peak distortion (MNLPD) and min-α. The first solution is based on MPD but avoids the problem of noise enhancement. The second solution finds the optimal of a family of equalizers derived from the MMSE and MPD criteria. We have shown by numerical calculation that by using the MNLPD or the min-α criteria we can achieve almost MinBER performance. The proposed methods have a larger complexity, but can be solved using well known techniques since they can be described as simple convex optimization problems