Given a behavioral description of a DSP algorithm represented by a dat
a-flow graph, we show how to obtain a rate-optimal static schedule wit
h the minimum unfolding factor under two models, integral grid model a
nd fractional grid model, and two kinds of implementations for each mo
del, pipelined implementation and non-pipelined implementation. We pre
sent a simple and unified approach to deal with the four possible comb
inations. A unified polynomial-time scheduling algorithm is presented,
which works on the original data-flow graphs without really unfolding
. The values of the minimum rate-optimal unfolding factors and the gen
eral properties for all the four combinations are proved.