Signal processing laboratory
The laboratory was established in 1972 and is engaged in theoretical research and practical development of digital signal processing systems, including the development of specific techniques and applications in analog-to-digital signal conversion. The work of the laboratory during these years is reflected in more than 200 publications, conference presentations, and monographs.
Currently, there are 11 people in the laboratory, including 3 researchers, and 1 scientific assistant.
Research and development areas:
- Virtual instruments based on advanced DSP technologies;
- Program-controlled radio devices, including those based on non-uniform sampling;
- Signal-dependent analysis of non-stationary signals, event-driven analog-to-digital conversions;
- Biometrics and brain signal processing;
- Microminiaturization of data acquisition and processing systems;
- Smart sensor and networked embedded system signal processing;
- Wireless sensor network systems, including sensor module hardware architecture, communication protocols, operating systems and application-oriented software;
- Applications of directional antenna arrays in wireless sensor networks;
- Transistor based UWB pulse generators and receivers;
- Wearable devices and their signal processing.
In recent years, two research groups have been established in the laboratory: one focused on developing wearable sensor systems, and the other on advancing ultra-wideband radar technology.
Wearable sensor group is working on wearable sensor system development with potential applications in medicine, sport and daily activities. Mainly systems are based on inertial sensors, but the group has also experience with bioelectric signals (ECG, EMG, EEG). Within group novel wired communication solution has been developed that allows data acquisition from several hundred sensors, using minimal wiring. The solution is further developed beyond the field of wearable sensor systems for monitoring the deformations of constructions.
Examples of developed technologies:
- 3D shape reconstruction fabric: https://www.youtube.com/watch?v=YDG0ERF2_d8
- human body motion model 3D reconstruction: https://www.youtube.com/watch?v=vAFCrMgJrmI
- human-computer interface development for people with disabilities: https://www.youtube.com/watch?v=tfiS01VfavU
Group competencies-expertise: sensor system development, inertial sensors, low power sensor system development, PCB design, Flexible PCB design, digital communication interfaces, Bluetooth and Bluetooth Low Energy communication in application level, inertial signal processing, bio-electric signal processing, machine learning algorithms, 3D visualization, simulations, software development for smart devices (Android OS smartphones, tablets) in wearable sensor context.
The Ultra wideband (UWB) radar team has been working on research and development of equivalent time conversion radar systems, resulting in both different unique solutions to improve radar performance and efficiency and several patents and publications on UWB signal generation, reception, processing, etc. Also, the group has developed a UWB radar device, which is used to study various UWB radar applications, such as:
- through wall measurements;
- ice thickness measurements;
- observation of non-contact signs of life (breathing, heartbeat);
- time domain reflectometry;
- antenna time domain measurements;
- measurements of material parameters.
Recent projects
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Body-Coupled Communication for Body Area Networks (BCC) #LCS (LZP)
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Contactless ice thickness measurement device (EDI-ICE) part 2 #LCS (LZP)
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Automated railway level crossing control system (PAKS) part 2 #LCS (LZP)
- Technology for high-precision time-amplitude analysis of event flow (TIME-AMP) #LCS (LZP)
- ACKCIO contract research project #Contract research (Līgumpētījumi)
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Digitalization of Power Electronic Applications within Key Technology Value Chains (PowerizeD) #ChipsJU
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Digital Accelerator of Latvia (DAoL) #Horizon Europe
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Physics Informed Machine Learning-Based Prediction and Reversion of Impaired Fasting Glucose Management (PRAESIIDIUM) #Horizon Europe
- Enhanced electromagnetic protection and cybersecurity through field-deployable innovative shielding, monitoring and data destruction technologies (EMI-CUBE / EMCFieldShield) #SRP (VPP)
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Sustainable and green electronics for circular economy (Sustronics) #ChipsJU
Publications
- Elise Saoutieff, Tiziana Polichetti, Laurent Jouanet, Adrien Faucon, Audrey Vidal, Alexandre Pereira, Sébastien Boisseau, Thomas Ernst, Maria Lucia Miglietta, Brigida Alfano, Ettore Massera, Saverio De Vito, Do Hanh Ngan Bui, Philippe Benech, Tan-Phu Vuong, Carmen Moldovan, Yann Danlee, Thomas Walewyns, Sylvain Petre, Denis Flandre, Armands Ancans, Modris Greitans, Adrian M. Ionescu. "A Wearable Low-Power Sensing Platform for Environmental and Health Monitoring: The Convergence Project", Sensors 2021. DOI: https://doi.org/10.3390/s21051802
- Atis Elsts. Demo: Large Scale Wireless Network Simulations with TSCH-Sim. EWSN '21: Proceedings of the 2021 International Conference on Embedded Wireless Systems and Networks. February 2021 Pages 181–182
- R. Maliks, G. Supols, E. Lobanovs and M. Greitans, "Integrated circuit of clocked comparator for ultra-wideband radar," 2021 IEEE
- A. Ancāns, M.Greitāns, R. Cacurs, B. Banga, A. Rozentāls "Wearable Sensor Clothing for Body Movement Measurement during Physical Activities in Healthcare", Sensors 2021, 21(6), 2068. DOI: https://doi.org/10.3390/s21062068
- V.Aristovs, G.Gaigals, G.Supols, E.Lobanovs, V.Riekstins, V.Zujs. 23 Apr 2021. "Ultra-Wideband Pulse Radar with Discrete Stroboscopic Receiver for Detection of Small Targets Behind Dielectric Obstacles", Transport and Telecommunication Journal, Volume 22, no. 2, pp.196-206, DOI: https://doi.org/10.2478/ttj-2021-0015
- Conformance analysis of model for material properties determination using simulation of ultra-wideband pulse radar
- Are Microcontrollers Ready for Deep Learning-Based Human Activity Recognition?
- V. Aristovs, M. Greitans. Determination of the Electrophysical Parameters of Dielectric Objects via the Processing of Ultra-Wideband Pulse Radar Signals
- Vladimir Aristov, Armands Ancans. Transient phenomena analysis of peak detector for nanosecond pulse amplitude measurement
- Didzis Lapsa, Rims Janeliukštis, Atis Elsts. Electrode Comparison for Heart Rate Detection via Bioimpedance Measurements
- Chloe Bae, Shiwen Yang, Michael Baddeley, Atis Elsts, Israat Haque. BlueTiSCH: A Multi-PHY Simulation of Low-Power 6TiSCH IoT Networks
- George Oikonomou, Simon Duquennoy, Atis Elsts, Joakim Eriksson, Yasuyuki Tanaka, Nicolas Tsiftes. The Contiki-NG open source operating system for next generation IoT devices
- Atis Elsts, Maksims Ivanovs, Roberts Kadikis, Olegs Sabelnikovs. CNN for Hand Washing Movement Classification: What Matters More-the Approach or the Dataset?
- Gatis Gaigals, Romans Maliks, Vladimir Aristov, Rolands Savelis, Janis Simanovics, Eduards Lobanovs, Haralds Egliens, Dans Laksis Kristaps Maris Greitans, Modris Greitans. Evaluation of Materials and Structures with a Multistatic Ultra-Wideband Impulse Radar: A Concept Validation
- V. Aristov, A. Elsts. Human Body as a Signal Transmission Medium for Body-Coupled Communication: Galvanic-Mode Models. Electronics 2023, 12(21), 4550. https://doi.org/10.3390/electronics12214550
- D. Lapsa, R. Janeliukstis, A. Elsts. Adaptive Signal-to-Noise Ratio Indicator for Wearable Bioimpedance Monitoring. Sensors 2023, 23(20), 8532. https://doi.org/10.3390/s23208532
- Armands Ancans.Wired Communication Protocol for Body Sensor Network: A Solution for Sensor Data Acquisition, IWoEDI'2023
- V. Aristov, "Transmission Sensing of Dielectric Objects for Determining the Geometric Shape of the Cross Section and the Detection of Internal Inhomogeneities" Automatic Control and Computer Sciences, volume 57, pp.196–202 (2023) , https://link.springer.com/article/10.3103/S0146411623020037
- V. Aristov, Remote Complex Resistance Measurement. Automatic Control and Computer Sciences, Volume 57, Issue 5 Oct, 2023, pp 469–472
- Didzis Lapsa, Margus Metshein, Andrei Krivošei, Rims Janeliukstis, Olev Märtens, Atis Elsts. Signal Acquisition and Algorithm Design for Bioimpedance-Based Heart Rate Estimation from the Wrist. Applied Sciences, 14(21), 9632
- V. Aristov, M.Greitans. "Study of a Radar Sensor Transmitter to Optimize a Bipolar Ultrawideband Pulse Used to Excite the Antenna" Automatic Control and Computer Sciences, 58(6)
- Niharika Panda, S. Muthuraman, Atis Elsts. 2024 ."Multi-Objective Optimization of Orchestra Scheduler for Traffic-Aware Networks" Smart Cities, 2024(7), pp.2542-2571. https://doi.org/10.3390/smartcities7050099
- Ingrida Lavrinovica, Janis Judvaitis, Dans Laksis, Marija Skromule, Kaspars Ozols "A Comprehensive Review of Sensor-Based Smart Building Monitoring and Data Gathering Techniques" Applied Sciences, 12(21) https://www.scopus.com/record/display.uri?eid=2-s2.0-85208554778&origin=resultslist
- Margus Metshein, Ksenija Pesti, Didzis Lapsa, Paul Annus, Rims Janeliukstis, Atis Elsts, Olev Martens. (2024, May). Evaluation of Two-Electrode System Configurations for Forearm Arteries Bioimpedance Measurement. In 2024 IEEE International Instrumentation and Measurement Technology Conference (I2MTC) (pp. 1-6). IEEE. https://ieeexplore.ieee.org/abstract/document/10561178
- Didzis Lapsa, Rims Janeliukstis, Margus Metshein, Leo Selavo. (2024). PPG and Bioimpedance-Based Wearable Applications in Heart Rate Monitoring—A Comprehensive Review. Applied Sciences, 14(17), 7451. https://www.mdpi.com/2076-3417/14/17/7451
- V. Aristov. 2024. "MONOSTATIC PULSED ULTRA-WIDEBAND RADAR ANTENNA FOR STUDYING BIOLOGICAL RHYTHMS OF THE HUMAN BODY AND INTERNAL INHOMOGENEITIES OF DIELECTRIC OBJECTS" Automatic Control and Computer Sciences, 58(1): pp.101-108 https://link.springer.com/article/10.3103/S0146411624010036
Recent patents
- LR patent Nr. 15854 B1, "METHOD OF STABILIZING THE PRECISION OF THE EVENT TIMER INTERPOLATOR"
- LR patent Nr. 15744 B1, "METHOD AND DEVICE FOR DETERMINING THE SHAPE AND ORIENTATION OF A TENSILE AND BENDING DEFORMED OBJECT"
- LR patent Nr. 15840 B1, "BRAIDED SELF-TENSIONING ELASTIC CABLE FOR WEARABLE SYSTEMS"
- LR patent Nr. 15878 A, "A DEVICE AND METHOD FOR EVALUATION OF QUALITY OF BIOIMPEDANCE SIGNAL"
Head of laboratory
Laboratory staff
