  The computational complexity of optimum decoding for an orthogonal space-time
block code G satisfying the orthogonality property that the Hermitian transpose
of G multiplied by G is equal to a constant c times the sum of the squared
symbols of the code times an identity matrix, where c is a positive integer is
quantified. Four equivalent techniques of optimum decoding which have the same
computational complexity are specified. Modifications to the basic formulation
in special cases are calculated and illustrated by means of examples. This
paper corrects and extends [1],[2], and unifies them with the results from the
literature. In addition, a number of results from the literature are extended
to the case c > 1.
