Rate-Optimal Schedule for Multi-Rate DSP Computations

In this paper, we present a novel framework of multi-rate scheduling of signal processing programs represented by regular stream flow graphs (RSFGs). The main contribution of this paper is translating the scheduling problem of RSFGs into an equivalent problem in the domain of Karp-Miller computation graphs. A distinct feature of our scheduling framework --- called multi-rate software pipelining --- is to allow maximum overlapping of operations from successive iterations subject only to precedence constraints caused by data dependences. Our framework combines the insights and experience from two seemingly different lines of research: static scheduling of application-specific programs and software pipelining of loops in general-purpose parallelizing compilers. We demonstrate that the scheduling of regular stream flow graphs can be formulated as a mathematical problem by capturing data dependencies between two actors as a precedence relation between the firing of these actors. Using linea..