On the Chandra-Poram-Bose symbol error probability expression for coherent orthogonal M-ary frequency shift keying

An expression for the average symbol error probability of coherent orthogonal M-ary frequency shift keying in generalized fading was recently reported by Chandra, Poram, and Bose. We show that the expression is only exact for M = 2; it does, however, provide an accurate approximation for M > 2. By modifying the derivation of the reported expression, we derive a lower bound for M <= 5 that has the same complexity as the reported expression, and we illustrate that, for M > 2, the expression of the derived bound provides an approximation that is also more accurate. Copyright (C) 2012 John Wiley & Sons, Ltd.