A Parallel Sliding-Window Generator for High-Performance Digital-Signal Processing on FPGAs

Abstract

Sliding-window applications, an important class of the digital-signal processing domain, are highly amenable to pipeline parallelism on field-programmable gate arrays (FPGAs). Although memory bandwidth often restricts parallelism for many applications, sliding-window applications can leverage custom buffers, referred to as sliding-window generators, that provide massive input bandwidth that far exceeds the capabilities of external memory. Previous work has introduced a variety of sliding-window generators, but those approaches typically generate at most one window per cycle, which significantly restricts parallelism. In this article, we address this limitation with a parallel sliding-window generator that can generate a configurable number of windows every cycle. Although in practice the number of parallel windows is limited by memory bandwidth, we show that even with common bandwidth limitations, the presented generator enables near-linear speedups up to 16x faster than previous FPGA studies that generate a single window per cycle, which were already in some cases faster than graphics-processing units and microprocessors.