Self-Calibrating Integrate-and-Fire Time Encoding Machine

Abstract: In this paper, we introduce a novel self-calibrating integrate-and-fire time encoding machine (S-IF-TEM) that enables simultaneous parameter estimation and signal reconstruction during sampling, thereby effectively mitigating mismatch effects. The proposed framework is developed over a new practical IF-TEM (P-IF-TEM) setting, which extends classical models by incorporating device mismatches and imperfections that can otherwise lead to significant reconstruction errors. Unlike existing IF-TEM settings, P-IF-TEM accounts for scenarios where (i) system parameters are inaccurately known and may vary over time, (ii) the integrator discharge time after firings can vary, and (iii) the sampler may operate in its nonlinear region under large input dynamic ranges. For this practical model, we derive sampling rate bounds and reconstruction conditions that ensure perfect recovery. Analytical results establish the conditions for perfect reconstruction under self-calibration, and evaluation studies demonstrate substantial improvements - exceeding 59dB - highlighting the effectiveness of the proposed approach.