On unlimited sampling and reconstruction
File(s)US_Manuscript_Final_Report.pdf (5.2 MB)
Accepted version
Author(s)
Bhandari, Ayush
Krahmer, Felix
Raskar, Ramesh
Type
Journal Article
Abstract
Shannon's sampling theorem is one of the cornerstone topics that is well understood and explored, both mathematically and algorithmically. That said, practical realization of this theorem still suffers from a severe bottleneck due to the fundamental assumption that the samples can span an arbitrary range of amplitudes. In practice, the theorem is realized using so-called analog--to--digital converters (ADCs) which clip or saturate whenever the signal amplitude exceeds the maximum recordable ADC voltage thus leading to a significant information loss. In this paper, we develop an alternative paradigm for sensing and recovery, called the Unlimited Sampling Framework. It is based on the observation that when a signal is mapped to an appropriate bounded interval via a modulo operation before entering the ADC, the saturation problem no longer exists, but one rather encounters a different type of information loss due to the modulo operation. Such an alternative setup can be implemented, for example, via so-called folding or self-reset ADCs, as they have been proposed in various contexts in the circuit design literature. The key task that we need to accomplish in order to cope with this new type of information loss is to recover a bandlimited signal from its modulo samples. In this paper we derive conditions when perfect recovery is possible and complement them with a stable recovery algorithm. The sampling density required to guarantee recovery is independent of the maximum recordable ADC voltage and depends on the signal bandwidth only. Our recovery guarantees extend to measurements affected by bounded noise, which includes the case of round-off quantization. Numerical experiments validate our approach. For example, it is possible to recover functions with amplitudes orders of magnitude higher than the ADC's threshold from quantized modulo samples upto the unavoidable quantization error. Applications of the unlimited sampling paradigm can be found in a number of fields such as signal processing, communication and imaging.
Date Issued
2020-12-04
Date Acceptance
2020-11-30
Citation
IEEE Transactions on Signal Processing, 2020, 69, pp.3827-3839
ISSN
1053-587X
Publisher
Institute of Electrical and Electronics Engineers
Start Page
3827
End Page
3839
Journal / Book Title
IEEE Transactions on Signal Processing
Volume
69
Copyright Statement
© 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Sponsor
UK Research and Innovation council
Identifier
http://alumni.media.mit.edu/~ayush/
Grant Number
Future Leaders Fellowship
Subjects
Science & Technology
Technology
Engineering, Electrical & Electronic
Engineering
Signal processing algorithms
Imaging
Dynamic range
Transfer functions
Radar imaging
Quantization (signal)
Hardware
Analog-to-digital conversion (ADC)
approx- imation
bandlimited functions
modulo
Shannon sampling theory
CMOS IMAGE SENSOR
DYNAMIC-RANGE
SIGNALS
Networking & Telecommunications
Publication Status
Published
Date Publish Online
2020-12-04