Wahab Khawaja

UWB Channel Sounding and Modeling for UAV Air-to-Ground Propagation Channels

Unmanned aerial vehicles (UAVs) are expected to be used extensively in the near future in applications such as aerial surveillance, transportation, and disaster assistance. The conditions under which UAVs operate are different from those of conventional piloted aircrafts. This necessitates development of new air-to-ground (AG) propagation channel models for UAVs. To our best knowledge, there are limited studies in the literature on sounding and modeling of ultrawideband (UWB) AG propagation channels. In this work, comprehensive UWB measurements are conducted for various UAV communication scenarios using Time Domain P410 UWB kits. Both time and frequency domain analysis of the measured data are carried out. Based on the measured data, stochastic path loss and multipath channel models are developed to characterize AG UWB propagation channels

UWB radar for indoor detection and ranging of moving objects: An experimental study

Ultrawideband (UWB) signals, due to their large bandwidth, can capture the fine temporal resolution of multipath propagation channel. This can be used for extracting geometric information related to the surrounding environment. In particular, Time Domain P410 UWB radios are used in our experiments, for channel sounding in bi-static and monostatic modes. In this paper, UWB radio pulses are used to determine the channel impulse response (CIR) in indoor environment. Based on the measured CIR, a statistical model is developed that is used in detection and range estimation of moving objects in indoor line-of-sight environment. The CIR measurements at different distances are used to study and model various channel characteristics in time and frequency domain. Our results show that UWB radar is capable of accurately detecting trajectory and speed of moving objects in indoor environments with minimum post-processing.

UWB radar based beyond wall sensing and tracking for ambient assisted living

Due to increase in the number of aging people worldwide, ambient assisted living (AAL) has been recently gaining extensive attention for autonomous monitoring of people in indoor environments. One possible way to fulfill this task is by using ultrawideband (UWB) radars. The UWB signals are ideal for detection, localization and mapping applications due to fine resolution of their multipath components, and can serve well for AAL scenarios. In this paper, using multiple UWB radar transceivers we introduce a fall detection, localization and tracking technique for people in need of assistance. The proposed method allows precise monitoring of people with special needs without any tags or wearables. To enhance ranging precision, we detect and discard outliers in the scanned UWB radar data collected by Time Domain P410 radios. A novel method of fall detection is introduced based on the residual covariance from extended Kalman filter (EKF). Computer simulations demonstrate the effectiveness of the proposed technique for AAL applications.