Comments on "on Probability of Error in Decision Feedback Equalizer"

The above-mentioned paper 1] derives bounds on the error probability of a decision feedback equalizer (DFE) which are claimed to be significantly tighter than the earlier upper bound of 2]. Unfortunately, 1] makes an unsupportable assumption which reddars the conclusions incorrect. We show that valid bounds can be obtained by the methods of 1], but that for the numerical example of 2] , the resulting upper bound is never tighter than, and sometimes significantly weaker than, that derived in 2]. Similarly, a lower bound derived by the method of 1] is shown for the same numerical example to be very close to the error-free past lower bound previously known.