Reduction of Depth of Boolean Networks with a Fan-In Constraint

In this paper we presentt family of techniques for the design of combinational networks whose objective is the reduction of the number of levels, subject to a constraint on the fan-in of the logic gates. We show that a Boolean expression with n literals and involving the connectivest AND and OR can be restructured so that the resulting network of AND and OR gates has depth at most C
l
log
2
n + δ, where a < 0.415 and C
l
is 1.81, 1.38, 1.18, and 1 for maximum fan-in l of 2,3,4, and 5, respectively. If we additionally require that the amount of equipment of the resulting network be bounded by a linear function of n, it is possible to bound the depth by 2 log
2
n with a fan-in of at most 3.