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Asynchronous processing of sparse signals.

Authors :
Can‐Cimino, Azime
Sejdić, Ervin
Chaparro, Luis F.
Source :
IET Signal Processing (Wiley-Blackwell); May2014, Vol. 8 Issue 3, p257-266, 10p
Publication Year :
2014

Abstract

Unlike synchronous processing, asynchronous processing is more efficient in biomedical and sensing networks applications as it is free from aliasing constraints and quantization error in the amplitude, it allows continuous–time processing and more importantly data is only acquired in significant parts of the signal. We consider signal decomposers based on the asynchronous sigma delta modulator (ASDM), a non‐linear feedback system that maps the signal amplitude into the zero‐crossings of a binary output signal. The input, the zero‐crossings and the ASDM parameters are related by an integral equation making the signal reconstruction difficult to implement. Modifying the model for the ASDM, we obtain a recursive equation that permits to obtain the non‐uniform samples from the zero‐time crossing values. Latticing the joint time‐frequency space into defined frequency bands, and time windows depending on the scale parameter different decompositions are possible. We present two cascade low‐ and high‐frequency decomposers, and a bank‐of‐filters parallel decomposer. This last decomposer using the modified ASDM behaves like a asynchronous analog to digital converter, and using an interpolator based on Prolate Spheroidal Wave functions allows reconstruction of the original signal. The asynchronous approaches proposed here are well suited for processing signals sparse in time, and for low‐power applications. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
17519675
Volume :
8
Issue :
3
Database :
Complementary Index
Journal :
IET Signal Processing (Wiley-Blackwell)
Publication Type :
Academic Journal
Accession number :
148455952
Full Text :
https://doi.org/10.1049/iet-spr.2013.0398