High Level Synthesis of an Event-Driven Windowing Process
Résumé
This work is a contribution to enhance the signal processing chain required in modern systems. The idea is to take advantage of the interesting features of both event-driven and well-established uniform sampling and signal processing algorithms. In this context, authors have proposed original windowing techniques for the event-driven sampled signal, activity selection and local parameter extraction. These are called as Activity Selection Algorithms (ASA). The proposed techniques correlate the windowing function length, shape and resampling frequency with the input signal time variations. In this paper, the ASA and an adaptive rate resampler with zero order interpolation are implemented in C. Using high level synthesis tools, synchronous and asynchronous register transfer level descriptions are synthesized on a commercial CMOS 40 nm technology. The synthesis results are presented. A comparison of the average power consumption between asynchronous and synchronous implementations is made. The proposed system functionality is also verified with the help of analytic test signals. Results have shown a compression, in terms of samples, of 1.5 to 1.6 respectively compared to the simple event-driven level-crossing sampling and by 5.8 to 9.3 compared to the uniform sampling based systems. The asynchronous (resp. synchronous) implementation of ASA and resampler only consumes in average 28pJ/sample (resp. 238 pJ/sample).