DAB Signal Preprocessing for Passive Coherent Location

Digital Audio Broadcast (DAB) transmitters can be successfully used as illumination sources in Passive Coherent Location (PCL). However, extending the integration time in such a configuration leads to the occurrence of periodical artifacts in the bistatic range/Doppler plots, resulting from the time structure of the DAB signal. In this paper, we propose some methods of signal preprocessing (based on symbol removal, substitution by noise, and duplication) that operate on the DAB transmission frame level and improve the received signal’s correlation properties. We also demonstrate that two of these methods allow us to avoid the mentioned artifacts and thus to improve the quality of the range/Doppler plots with detection results. We evaluate the performance of the proposed methods using real DAB signals acquired in an experimental PCL platform. We also provide the analysis of the Signal to Noise Ratio (SNR) during the detection of a moving target which shows that the proposed solution, based on symbol duplication, can offer around 3 dB of gain in SNR. Finally, we carry out the computational complexity analysis showing that the proposed method can be implemented with a minimal cost after some optimizations.

Maximum Marginal Approach on EEG Signal Preprocessing for Emotion Detection

Emotion detection is an important research issue in electroencephalogram (EEG). Signal preprocessing and feature selection are parts of feature engineering, which determines the performance of emotion detection and reduces the training time of the deep learning models. To select the efficient features for emotion detection, we propose a maximum marginal approach on EEG signal preprocessing. The approach selects the least similar segments between two EEG signals as features that can represent the difference between EEG signals caused by emotions. The method defines a signal similarity described as the distance between two EEG signals to find the features. The frequency domain of EEG is calculated by using a wavelet transform that exploits a wavelet to calculate EEG components in a different frequency. We have conducted experiments by using the selected feature from real EEG data recorded from 10 college students. The experimental results show that the proposed approach performs better than other feature selection methods by 17.9% on average in terms of accuracy. The maximum marginal approach-based models achieve better performance than the models without feature selection by 21% on average in terms of accuracy.

Analisis Aplikasi Filter FIR dan Filter IIR dalam Pra-pemrosesan Sinyal Elektroensefalografi

– Electroencephalography (EEG) is a method used to analyze brain activities, detect abnormalities in brain, and diagnose brain-related disease. To extract information from EEG signal, preprocessing steps such as Fast Fourier Transform (FFT), filter, and wavelet decomposition will be needed. This paper primarily focuses on implementation of Finite Impulse Response (FIR) and Infinite Impulse Response (IIR) filter design in EEG signal preprocessing in MATLAB software. The result of the simulation indicates that each filter design implemented in EEG preprocessing has different performance and side effect toward signal processing parameters such as phase distortion, amplitude ratio, and processing time. Filter design type implementation also affect power and entropy calculation result. Keywords – EEG, FIR filter digital, IIR filter digital, Wavelet Decomposition, GUI-MATLAB