• A Dynamic Channel Model for Indoor Wireless Signals: Working Around Interference Caused by Moving Human Bodies 

      Mohamed, Marshed Kassim; Cheffena, Michael; Fontán, Fernando Pérez; Moldsvor, Arild (Journal article; Peer reviewed, 2018)
      The use of indoor wireless devices has substantially increased in recent years. This escalation is due to the expansion of traditional communication devices, such as mobile phones and laptop computers, to less traditional ...
    • Acoustic-and Radio-Frequency-Based Human Activity Recognition 

      Mohtadifar, Masoud; Cheffena, Michael; Pourafzal, Alireza (Peer reviewed; Journal article, 2022)
      In this work, a hybrid radio frequency (RF)- and acoustic-based activity recognition system was developed to demonstrate the advantage of combining two non-invasive sensors in Human Activity Recognition (HAR) systems and ...
    • Advanced RF/microwave Systems for Sensing and Communication Applications 

      Alam, Tanjir (Doctoral theses at NTNU;2023:191, Doctoral thesis, 2023)
      As the fifth generation (5G) and beyond networks as well as the Internet-of-things (IoT) continue to expand and become more prevalent in various industries, we will encounter connected devices almost everywhere. Consequently, ...
    • Buffer Delay Improvement in Gait-Cycle-Driven Transmission Power Control Scheme for WBAN 

      Mohamed, Marshed Kassim; Cheffena, Michael; Ai, Yun; Al-Samman, Ahmed (Peer reviewed; Journal article, 2020)
      Due to the dynamic nature of the wireless body area network (WBAN) channels, there is a need for dynamic transmission power control (TPC) to increase their energy efficiency. The existing gait-cycle-driven TPC (G-TPC) ...
    • Capacity Analysis of PLC Systems over Rayleigh Fading Channels with Nakagami- Additive Noise 

      Ai, Yun; Cheffena, Michael (Chapter, 2016)
      Power line communication (PLC) is an emerging technology for the realization of smart grid and home automation. It utilizes existing power line infrastructure for data communication in addition to the transmission of power. ...
    • Channel-based Optimal Back-off Delay Control in Delay-Constrained Industrial WSNs 

      Li, Qihao; Zhang, Ning; Cheffena, Michael; Shen, Xuemin (Sherman) (Journal article; Peer reviewed, 2019)
      Recent developments in industrial wireless sensor networks (IWSNs) have revolutionized industrial automation systems. However, harsh industrial environment poses great challenges to a time-critical and reliable wireless ...
    • Channel-based Sampling Rate and Queuing State Control in Delay-Constraint Industrial WSNs 

      Li, Qihao; Zhang, Kuan; Cheffena, Michael; Shen, Xuemin (Sherman) (Journal article, 2017)
      Industrial Wireless Sensor Networks (IWSNs) improve the transmission precision of control signaling as well as contributing to the real-time data monitoring and instrument fault diagnosing throughout the manufacturing ...
    • Channel-based Sybil Detection in Industrial Wireless Sensor Networks: a Multi-kernel Approach 

      Li, Qihao; Zhang, Kuan; Cheffena, Michael; Shen, Xuemin (Sherman) (Journal article, 2017)
      Industrial Wireless Sensor Networks (IWSNs) integrate various types of sensors to measure and control industrial production. However, the unattended open environment makes IWSNs vulnerable to malicious attacks, such as ...
    • Characterization of dynamic wireless body area network channels during walking 

      Mohamed, Marshed Kassim; Joseph, Wout; Vermeeren, Günter; Tanghe, Emmeric; Cheffena, Michael (Journal article; Peer reviewed, 2019)
      In this work, finite-difference time-domain was used for the investigation of dynamic wireless body area network channel characteristics during walking, thus accounting for dynamic aspects and body postures. This involves ...
    • Characterization of Off-Body Area Network Channels During Walking 

      Mohamed, Marshed Kassim; Joseph, Wout; Varmeeren, Günter; Tanghe, Emmeric; Cheffena, Michael (Journal article; Peer reviewed, 2019)
      In this work, the off-body area network channel characteristics during walking were investigated using finite difference time-domain. The channels were investigated in terms of fade variation and the correlation between ...
    • Characterization of the Body-to-Body Propagation Channel for Subjects during Sports Activities 

      Mohamed, Marshed Kassim; Cheffena, Michael; Moldsvor, Arild (Journal article; Peer reviewed, 2018)
      Body-to-body wireless networks (BBWNs) have great potential to find applications in team sports activities among others. However, successful design of such systems requires great understanding of the communication channel ...
    • Communication Technologies for Smart Grid: A Comprehensive Survey 

      Abrahamsen, Fredrik Ege; Ai, Yun; Cheffena, Michael (Peer reviewed; Journal article, 2021)
      With the ongoing trends in the energy sector such as vehicular electrification and renewable energy, the Smart Grid (SG) is clearly playing a more and more important role in the electric power system industry. One essential ...
    • A Comparative Study of Wireless Channel Propagation Characteristics in Industrial and Offce Environments 

      Ai, Yun; Cheffena, Michael (Research report, 2015)
      This paper presents the comparative results of channel measurements in an industrial facility and an indoor office. The frequency domain channel measurements have been carried out in the frequency band of 0.8.2.7 GHz. ...
    • Comprehensive Physical Layer Security Analysis of FSO Communications over Málaga Channels 

      Ai, Yun; Mathur, Aashish; Verma, Gyan Deep; Kong, Long; Cheffena, Michael (Peer reviewed; Journal article, 2020)
      In this paper, we study the physical layer security of free-space optical (FSO) communications under different eavesdropping scenarios. More specifically, the secrecy performance of FSO communication employing intensity ...
    • Dual-functional communication and sensing antenna system 

      Alam, Tanjir; Cheffena, Michael; Rajo-Iglesias, Eva (Peer reviewed; Journal article, 2022)
      In this article, a dual functional antenna system for communication and sensing applications is designed on a single substrate having a common input port. The main motivation behind the proposed design is to build an antenna ...
    • Dynamic Channel Models for Wireless Body Area Networks 

      Mohamed, Marshed Kassim (Doctoral theses at NTNU;2018:240, Doctoral thesis, 2018)
      The advancements in technology have made it possible to create a network of implant and wearable nodes around the human body known as wireless body area network (WBAN). These communication systems have potentially great ...
    • Effect of Weather Condition on LoRa IoT Communication Technology in a Tropical Region: Malaysia 

      Al-Samman, Ahmed; Cheffena, Michael; Elijah, Olakunle; Rahim, Sharul Kamal Abdul; Sittakul, Vitawat; Din, Jafri Bin; Tharek, Abdul R. (Peer reviewed; Journal article, 2021)
      An experimental study on the effect of weather conditions such as solar radiation, humidity, temperature, and rain on the Long Range (LoRa) communication in a tropical region (Malaysia) via a campus environment has been ...
    • Effective Throughput Analysis of α-η-κ-µ Fading Channels 

      Ai, Yun; Mathur, Aashish; Kong, Long; Cheffena, Michael (Peer reviewed; Journal article, 2020)
      The α-η-κ-μ fading model is a very useful instrument to accurately describe various radio wave propagation scenarios. In this paper, we study the effective throughput performance of communication systems over the α-η-κ-μ ...
    • Empirical Path Loss Models for Wireless Sensor Network Deployment in Snowy Environments 

      Cheffena, Michael; Mohamed, Marshed Kassim (Journal article; Peer reviewed, 2017)
      Abstract: In this paper, practical sensor nodes are utilized to study the path loss effects of wireless sensor networks (WSNs) at 2.425 GHz in a ground covered by snow at different heights from the ground. The measurement ...
    • Energy-Efficient and Low-Cost Wireless Sensor System Designs Based on Spectral Lines Analysis 

      Pourafzal, Alireza (Doctoral theses at NTNU;2023:441, Doctoral thesis, 2023)
      This thesis presents a comprehensive investigation into the development of energy-efficient, low-cost wireless sensor systems in the context of the Internet of Things landscape. We examined two sensor technologies, microwave ...