Linear-Bias Time Encoding for Low-Rate Quantized Representation of Bandlimited Signals

TL;DR

This paper introduces a linear-bias IF-TEM that dynamically tracks the input signal, reducing oversampling and enabling efficient low-bitrate encoding of bandlimited signals with maintained accuracy.

Contribution

The paper proposes a novel LB-IF-TEM with dynamic bias tracking, improving encoding efficiency and providing theoretical bounds and experimental validation.

Findings

Achieves comparable reconstruction accuracy at lower bitrate.

Reduces oversampling compared to conventional IF-TEMs.

Provides explicit bounds on oversampling range.

Abstract

Integrate-and-fire time encoding machines (IF-TEMs) provide an efficient framework for asynchronous sampling of bandlimited signals through discrete firing times. However, conventional IF-TEMs often exhibit excessive oversampling, leading to inefficient encoding for signals with smoothly distributed information. This letter introduces a linear-bias IF-TEM (LB-IF-TEM), where the bias dynamically tracks the input signal to maintain a nearly constant integrator input, thereby localizing the firing intervals. The resulting concentrated distribution enables effective non-uniform quantization with reduced distortion. Theoretical analysis establishes explicit bounds on the achievable oversampling range, while experimental results demonstrate that the proposed method attains comparable reconstruction accuracy at significantly lower bitrate than existing IF-TEM variants. The LB-IF-TEM thus provides a low-power, communication-efficient, and analytically tractable framework for time-based signal encoding and reconstruction.