A family of n-dimensional vectors with unit norm is a Euclidean superimposed code} if the sums of any two distinct set of at most m of the vectors are separated by a certain minimum Euclidean distance d. Ericson and Gyorfi (1988) proved that the rate of such a code is between (log m)/4m and (log m)/m for m sufficiently large. In this talk -- improving the above longstanding best upper bound for the rate -- it is shown that the rate is always at most (log m)/2m, i.e., the size of a possible superimposed code is at most the square root of the earlier bound.

This is a joint work with M. Ruszinko.

Tuesday - November 4, 1997.
4:00 PM - 241 Altgeld Hall - COMBINATORICS AND GRAPH THEORY SEMINAR