WE2.R4.2

Non-Linear Analog Processing Gains in Task-Based Quantization

Marian Temprana Alonso, Farhad Shirani, Florida International University, United States; Neil Irwin Bernardo, University of the Philippines Diliman, Philippines; Yonina C. Eldar, Weizmann Institute of Science, Israel

Session:
Entropy coding, compression and quantization

Track:
10: Source Coding and Data Compression

Location:
Omikron II

Presentation Time:
Wed, 10 Jul, 11:50 - 12:10

Session Chair:
Elza Erkip, NYU
Abstract
In task-based quantization, a multivariate analog signal is transformed into a digital signal using a limited number of low-resolution analog-to-digital converters (ADCs). This process aims to minimize a fidelity criterion, which is assessed against an unobserved task variable that is correlated with the analog signal. The scenario models various application of interest such as channel estimation, medical imaging applications, and object localization. This work explores the integration of analog processing components—such as analog delay elements, polynomial operators, and envelope detectors—prior to ADC quantization. Specifically, four scenarios, involving different collections of analog processing operators are considered: (i) arbitrary polynomial operators with analog delay elements, (ii) limited-degree polynomial operators, excluding delay elements, (iii) sequences of envelope detectors, and (iv) a combination of analog delay elements and linear combiners. For each scenario, the minimum achievable distortion is quantified through derivation of computable expressions in various statistical settings. It is shown that analog processing can significantly reduce the distortion in task reconstruction. Numerical simulations in a Gaussian example are provided to give further insights into the aforementioned analog processing gains.
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