The research in radio system group covers a wide range of topics from designing physical layer (PHY) for wireless communication systems to signal processing algorithms, radio propagation, channel modelling and antenna design. In addition to the theoretical components, we are interested in practical aspects. That is why digital implementation of the signal processing algorithms, prototyping communication systems using SDRs, building and testing the designed antennas and practical channel measurements are also integral part of the research work in our group. We try to give (at least) a touch of practical experience wherever possible. 


  • 4TU.NIRICT Intelligent Long-range Wi-Fi

    Wi-Fi is dominating the wireless local area networks. To make it also a competitive technology for the next-generation IoT, Wi-Fi HaLow with distinct new IoT features has been released by Wi-Fi Alliance and has attracted extensive attentions [1]. Same to other existing IoT technologies such as LoRa and NB-IoT, Wi-Fi HaLow is long-range (>1 km) and low-power, but meanwhile HaLow can offer much higher data rate (e.g., >100x at 1 km distance), native IP support, and can be seamlessly integrated into the pervasively existing Wi-Fi access points without extra deployment cost. Operating at the sub-GHz frequency spectrum band, Wi-Fi HaLow increases the traditional Wi-Fi ubiquity, making it suitable for intelligent IoT applications such as smart city and precision agriculture. Though promising, HaLow is facing several challenges, such as cumbersome provisioning of massive number of devices, limited long-range (only >1 km), and inefficient resource management. More urgently, active national/international HaLow communities are in high demand to boost its technology evolution and application development.

    Our overarching objective is to combine the unique expertise of the RS Group of UTwente (radio wave propagation), the ENS group of TU Delft (networked system design), and the INF Group of WUR (AIIoT), to make 4TU become a front-runner HaLow community for next-generation IoT. In details, we target the following objectives: A joint platform on intelligent HaLow. It includes: 1) HaLow end nodes that are used for data collection, embedded AI processing and data communication; 2) HaLow access points in mesh topology for data communication and edge intelligence. Case study: HaLow empowered precision agriculture. We will build a proof-of-concept system to realize an Internet of Smelling in an agricultural setup. In this system, sensors and HaLow nodes are deployed on objects and animals to monitor surrounding smells. Community development. We will organize various types of community inter-connection activities to boost academic communications and cooperation among 4TU universities, such as workshops, open courses, and research competitions. Leverage effect. We will apply for follow-up external grants to mature the promising Wi-Fi HaLow technology, e.g., NWO OTP.

    UT Contact Person: Yang Miao, Andre Kokkeler

  • Passive Posture Recognition of Multiple Human Using Radio Technology

    Using radio signals (propagating electromagnetic waves) does not put constraints on the lighting conditions of environment and does not pose privacy concerns as image-based systems. For indoor scenarios like home or hospital, the background objects in addition to human can be diverse (in geometry and dielectric properties) and may present in mobility.

    Environment-aware studies on (1) how radio waves interact with human body and background objects, as well as (2) how to identify human in space and recognize their posture, are called for, in order to achieve a wireless-assisted human-care. To this end, an optimized yet efficient system with multi-static multi-antenna arrays embedded in buildings/rooms will be designed. The system requirement including spatial and delay resolutions, coverage, sampling, etc., will be assessed with desired accuracy. Algorithms on localization, identification and posture recognition of persons will be devised in a multidisciplinary manner, i.e., hybrid use of radio signals, machine learning, offline and real-time optimization, other non-visual sensors.

    This research theme is embarking at the right time for the future 6G communication technologies, where multi-antenna systems are used collaboratively and inclusively for not only advancing communication features but also benefiting localization and sensing possibilities with human “touch”.

    Participating Members: Yang Miao , Hadi Alidoustaghdam

  • AAA

    Participating Members: André Kokkeler, Shubham Yadav

  • UT-5G

    Participating Members: André Kokkeler, Stef van Zanten

  • Wavecomb

    This project has received funding from the European Union Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 766231 WAVECOMBE H2020-MSCA-ITN-2017. The foreseen exponential growth of mobile data traffic will not be uniform across geographical areas but is mainly concentrated in hot spots that are usually located in the built environments (BEs) such as central business districts, stations, airports, stadiums, dense urban environments, etc. This poses considerable challenges that we believe can be solved by ultra-dense deployment of millimetre-wave (mmW) small-cells (SCs) in conjunction with massive multiple-input multiple-output (MIMO) in 5G and beyond 5G (B5G) wireless networks. However, there are a number of research challenges that need to be addressed for a successful deployment of 5G/B5G wireless networks: even if the theoretical background of massive MIMO is by now rather complete, the actual performance characterization and measurements of mmW antenna arrays have not yet been fully addressed at either the component or system level; mmW radio channel measurements have been performed but with limited time delay resolution, single antennas and over single radio links; and mmW bands have been considered for mobile communications, but the level of detail and diversity of BEs necessary for meaningful mmW SC deployment has not been fully exploited. Therefore, we propose here a research approach that combines the three disruptive key enabling technologies for 5G/B5G with the aim to answer fundamental questions that are still not well understood. Objectives: Develop and test mmW MIMO and massive MIMO antennas. Characterize and model radio propagation channel at mmW bands for typical BEs (offices, homes, stations, airports). Characterize and model the effect of the human body on MIMO radio propagation at mmW bands. Theoretically analyze and optimize massive MIMO mmW SC performance in the BEs. Jointly optimize the planning/deployment of massive MIMO mmW SC networks and their operating environments. Develop methods to retrofit existing buildings and to design new buildings for efficient high-capacity wireless communications in the BEs.

    Collaborators: This project involves several partners from academia and industry for more information please visit:

    Participating Members: Andrés Alayon GlazunovWai Yan YongMohammad PoordaraeeChunxia QinAlireza Bagheri

  • The OTA Project

    Through the past decades, the research area of antenna measurements (AMs) has undergone disruptive changes that have been stimulated by the development of novel wideband multiple-input multiple-output (MIMO) antenna systems and beamforming applications for wireless communications (e.g., 5G). The modern area of AM research can be referred to as Over-The-Air (OTA) characterization of antenna systems. OTA evaluates the impact of hardware, wave propagation, signal processing on the overall performance of the antenna system with regard to the most relevant parameters of wireless network performance. The key game changers and associated challenges that shape the OTA research come from the global shift towards massive multi-antenna systems (aka Massive MIMO), more advanced (hybrid analog-digital) signal processing, and much higher levels of integration between individual components (including active components too) and sub-systems. Performance testing of such advanced antenna systems requires sophisticated test methods and often new types of measurement tools. Moreover, until recently, testing of radio base stations could be performed conductively at a test port. This option is not sustainable for a large number of antenna ports and in fact, it is not even technically possible when going Massive MIMO at higher frequency bands, eg., at the mmWave frequency bands. OTA is therefore indispensable to characterize the performance of radio base stations at mmWaves but is also beneficial at lower frequencies too.

    Participating Members: Andrés Alayon Glazunov, Noud Kanters

  • Zero: Towards Energy Autonomous Systems for IoT

    Participating Members: André Kokkeler, Hans de Jong

  • MIRABeam: Multi-beam Interference Robust Adaptive Beamforming

    Participating Members: André Kokkeler, Masoud Abbasi Alaei

  • IRUDIT- Interference Robust Ultra-low-power Digital Inspired Transceiver

    Participating Members: André Kokkeler, Mina Mikhael Mitry

  • Beyond Bugging: wireless sensing and monitoring with harmonic radar

    Beyond Bugging is a NWO-funded VENI research project that aims at developing an innovative system for tracking of passive harmonic tags. 

    Remote, non-contact, wireless monitoring is becoming a common feature of many industrial, agricultural, environmental and societal systems. Despite a variety of commercially available solutions, there are still significant gaps in the technology landscape when it comes to tracking of small wildlife for ecological and conservation research, search and rescue, and buried infrastructure control. The main difficulties in these applications arise from the need to operate in highly cluttered environments. This is often further complicated by the stringent size, weight, and battery life requirements of the devices (tags) that are placed on the objects of interest to enable their monitoring.

    In this project, innovative solutions to this problem will be developed by utilizing the harmonic radar (HR) sensing principle. In HR, the object of interest is equipped with a simple harmonic transponder tag which is designed to produce a nonlinear response when illuminated by an interrogating radio signal. As a result, the signal that arrives back at the receiver has a distinct carrier frequency, enabling sensing functionality in situations where linear techniques are ineffective due to clutter. However, current HR implementations that follow this basic operation principle suffer from a number of fundamental limitations that severely restrict their applicability, such as low operational range, bulky and expensive system designs, and absence of multi-tag tracking mechanisms. The gola of this project is to overcome these limitations by utilizing the full potential of the harmonic operation to deliver low-cost, flexible system designs that provide increased operational range and accurate multi-target tracking with simple, battery-free harmonic tags. Knowledge generated in this project has significant potential impact in harmonic-based sensing systems, wireless power transfer and zero-energy communications, or where any passive, or actively transmitting, targets need to be detected and tracked.

    Participating members: Anastasia Lavrenko

  • Green Sensors

    The Green Sensors project aims at the development of IoT- and ICT systems for partially or fully biodegradable electronic sensing devices that are operational for a predetermined period of operation, allowing the wireless transmission of data. Different transmitter-, receiver-, antenna- and power transfer architectures are investigated, as well as suitable materials to produce them. The goal is to research sensing devices that are made of 100% green and biodegradable electronics. These sensors will be capable of transmitting sensor data to a central point, where this data will be further processed to be used to optimize growing conditions of plants. This also involves optimization of energy usage, exploring means to handle small link budgets and to trade-off local processing (e.g. via extremely efficient AI) versus central processing.

    Participating members: André Kokkeler, Sujith Raman

  • 3D-ComS

    Towards 6G, millimeter-wave (mmWave) frequencies are used for high-speed communication, focusing beams towards users in nanocells spreading tens of meters. Advancement in mmWave communication devices also results in accurate sensing of environment. Sensing while communication is crucial to prevent the communication performance degradation caused by dynamic blockages (e.g., humans, vehicles). In 3D-ComS, we exploit a unique set of expertise to advance joint communication and sensing. We will design a 3D mmWave array system with a minimal number of active, highly integrated antennas to enable digital beamforming at lower power consumption, and seek meaningful trade-offs between data rates and sensing performances.

    3D-ComS aims for innovations on shared array aperture, receiver, and radio resource allocation for the integrated functionality of communication and sensing. 

    Participating members: Yang Miao, André Kokkeler, Nguyen Dao


  • Slow Wireless

    The “Slow Wireless” project focused on radio links in wireless sensor networks that need low data rates (bytes/second). The conventional approach is to use duty cycling: turn off the radio in the node for most of the time, and transmit the data in short bursts to save energy. The radio is often a fairly standard radio, optimized for low-power duty-cycled operation. Because of timing uncertainties in the receive and transmit time slots, both should be turned on longer than necessary. To circumvent this problem, and to achieve lower receiver power in general, there has been high scientific interest in ultra-low-power (microW) receivers, which have been realized with varying performance. Similarly, there has been attention for wake-up receivers: receivers that use very little power and ‘listen’ whether they should wake up the main radio. A major problem for published low-power receivers is that they are not very robust to interference, most of them not at all. Ultra- wideband (UWB) techniques can solve this, but the power consumption would be very high.

    In this project we went in the opposite direction, and explored very narrowband systems. Most interference nowadays is wideband, because it uses spread spectrum or OFDM, as in Bluetooth and Wi-Fi. By choosing a very narrowband system, most interference can be filtered out, even when the interference frequency band covers the desired communication channel.

    To research such an approach, we brought together expertise from three distinct areas: telecommunication engineering, integrated circuit design and embedded computer architecture design. In three closely related work packages we explored the implications and opportunities for the link behavior, fading, frequency control, modulation techniques and radio architecture. Our results indicate that there are good opportunities to arrive at low-power, interference-robust radios, and the research in this project contributed significantly to clarify the trade-offs involved and to arrive at an actual demonstrator implementation.

    Paticipating Members: André KokkelerSiavash SafapourhajariZaher Mahfouz

  • Indoor Small-Cell Networks with 3D MIMO Array Antennas (is3DMIMO)

    This project has received funding from the European Union Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No. 734798 is3DMIMO H2020-MSCA-RISE-2016. It is predicted that wireless network traffic will increase 1000 times in the next decade. The exponential traffic growth is not uniform across geographical areas and mainly takes place in indoor hot spots. Hence, high capacity indoor venues represent the biggest network capacity increase challenge. The recently emerged 3D MIMO technology provides a promising dimension to provide an extra capacity gain in hot spots. In particular, the 3D deployment of small cells (SCs) equipped with 3D MIMO antenna arrays will take advantage of the 3D distribution of user equipment (UE) in typical high capacity venues, and represents an excellent technical combination to address the indoor high capacity challenge. The 3D deployment of SCs with 3D MIMO antenna arrays faces technical challenges ranging from 3D MIMO antenna array design, performance evaluation, the lack of understanding of 3D MIMO SC network performance limits to the optimal 3D SC network deployment.

    Collaborators: This project involves several partners from academia and industry for more information please visit:

    Participating Members: Andrés Alayon Glazunov