Multipath Exploitation for Human Activity Recognition using a Radar Network

In this study, the problem of multipath in radar sensor networks for human activity recognition (HAR) has been examined. Traditionally considered as a source of additional clutter, the multipath is being investigated for its potential to be exploited through the creation of virtual radar nodes. These virtual nodes are conceptualized to...

Design of Sparse Multiband Signal for Precise Positioning with Joint Low-Complexity Time Delay and Carrier Phase Estimation

This paper presents a methodology to design a sparse multiband ranging signal with a large virtual bandwidth, from which time delay and carrier phase are estimated by a low complexity multivariate maximum likelihood (ML) method. In the estimation model for a multipath channel, not all reflected paths are considered, and time delay and carrier...

Enabling Robust Radar-based Localization and Vital Signs Monitoring in Multipath Propagation Environments

Objective: Over the last two decades, radar-based contactless monitoring of vital signs (heartbeat and respiration rate) has raised increasing interest as an emerging and added value to health care. However, until now, the flaws caused by indoor multipath propagation formed a fundamental hurdle for the adoption of such technology in practical...

Experimental Evaluation of Smartphone Accelerometer and Low-Cost Dual Frequency GNSS Sensors for Deformation Monitoring

Smartphone accelerometers and low-cost Global Navigation Satellite System (GNSS) equipment have faced rapid and important advancement, opening a new door to deformation monitoring applications such as landslide, plate tectonics and structural health monitoring (SHM). The precision potential and operational feasibility of the equipment play an...

Positioning in a Multipath Channel Using OFDM Signals with Carrier Phase Tracking

In developing a high accuracy terrestrial radio navigation system, as a complement to a global navigation satellite system (GNSS), it is recognized that the performance of time delay estimation is proportional to, and thereby limited by, the signal bandwidth. Given a possibly narrow signal bandwidth, the central carrier phase can,...

Precise regional L5 positioning with IRNSS and QZSS: stand-alone and combined

In this contribution we analyze the single-frequency L5 positioning capabilities of the two regional satellite navigation systems IRNSS and QZSS, stand alone as well as combined. The positioning analysis is done for two different baselines, having a mix of receivers, providing ambiguity-float and ambiguity-fixed positioning for models with...

Australia-first high-precision positioning results with new Japanese QZSS regional satellite system

The Japanese Quasi-Zenith Satellite System (QZSS) has recently (October 2017) reached its first 4-satellite constellation. In this contribution, the standalone performance of this 4-satellite QZSS constellation is assessed by means of its triple-frequency (L1 + L2 + L5) real-time kinematic (RTK) integer ambiguity resolution and precise...

Multipath Wide-Bandwidth CMOS Magnetic Sensors

This paper proposes a multipath multisensor architecture for CMOS magnetic sensors, which effectively extends their bandwidth without compromising either their offset or resolution. Two designs utilizing the proposed architecture were fabricated in a 0.18-μm standard CMOS process. In the first, the combination of spinning-current Hall sensors...

Doppler-Resilient Orthogonal Signal-Division Multiplexing for Underwater Acoustic Communication

Underwater acoustic (UWA) channels are characterized by a severe spread in time and frequency, and are usually labeled as “doubly spread channels.” In this paper, we propose Doppler-resilient orthogonal signal-division multiplexing (D-OSDM), to provide a highly reliable communication environment in doubly spread channels for UWA communication. D...

Short and zero baseline analysis of GPS L1 C/A, L5Q, GIOVE E1B, and E5aQ signals

Stochastic properties of GNSS range measurements can accurately be estimated using a geometry-free short and zero baseline analysis method. This method is now applied to dual-frequency measurements from a new field campaign. Results are presented for the new GPS L5Q and GIOVE E5aQ wideband signals, in addition to the GPS L1 C/A and GIOVE E1B...

Geometry-free undifferenced, single and double differenced analysis of single frequency GPS, EGNOS and GIOVE-A/B measurements

This paper demonstrates a geometry-free GNSS measurement analysis approach and presents results of single frequency GPS, EGNOS and GIOVE short and zero baseline measurements. The purpose is to separate the different contributions to the measurement noise of pseudo range code and carrier phase observations at the receiver. The influence of...

Principles and Limitations of Ultra-Wideband FM Communications Systems

This paper presents a novel UWB communications system using double FM: a low-modulation index digital FSK followed by a high-modulation index analog FM to create a constant-envelope UWB signal. FDMA techniques at the subcarrier level are exploited to accommodate multiple users. The system is intended for low (110 kbps) and medium (1001000 kbps)...