A denoising autoencoder based on U-Net and bidirectional long short-term memory for multi-level random telegraph signal analysis.

Random telegraph signals (RTSs) are specific time-fluctuating signal patterns marked by a series of distinctive switching events between well-defined signal levels. These signals are ubiquitous in many electronic, chemical, and biological devices and systems. Analyzing RTSs unveils associated system structures and internal operation mechanisms, offering valuable insights into performance sensitivity. Therefore, accurate parameter quantification of RTSs is essential for understanding their origin and significance. While two-level RTS analysis is straightforward, complications arise at multiple levels, especially with unwanted background fluctuations. To address this challenge, we developed a novel denoising autoencoder model with U-Net and bidirectional long short-term memory (DAE UBL) for denoising multi-level RTSs degraded by Gaussian white and pink noise. DAE UBL extracts lower-dimensional latent features with its encoder and reconstructs denoised RTS with its decoder. Trained and validated with large datasets of noisy multi-level RTSs, our DAE UBL demonstrates superior and stable denoising performance compared to four classic models with lower average median root mean squared errors by over 78% and 63% for all RTS data accompanying various strengths of white noise and pink noise. Average median signal-to-noise ratios in the DAE UBL analysis are increased by over 65% and 56% for the white noise and pink noise datasets. In the time domain, DAE UBL effectively suppresses both local and global fluctuations, thereby successfully removing background noise. Our model exhibits robust performance in denoising multi-level RTSs with strong pink noise. We envision that our DAE UBL will be an attractive denoising methodology for the complex multi-level RTS analysis. • We build novel denoising autoencoder for complex random telegraph signal analysis. • Our denoising autoencoder effectively suppresses local and global background noise. • We successfully identify digitized telegraph signals from noisy multilevel data. • We give extensive performance results of many multilevel random telegraph signals. [ABSTRACT FROM AUTHOR]