Multipath-assisted maximum-likelihood indoor positioning using UWB signals

Multipath-assisted indoor positioning (using ultrawideband signals) exploits the geometric information contained in deterministic multipath components. With the help of a-priori available floorplan information, robust localization can be achieved, even in absence of a line-of-sight connection between anchor and agent. In a recent work, the Cramér-Rao lower bound has been derived for the position estimation variance using a channel model which explicitly takes into account diffuse multipath as a stochastic noise process in addition to the deterministic multipath components. In this paper, we adapt this model for position estimation via a measurement likelihood function and evaluate the performance for real channel measurements. Performance results confirm the applicability of this approach. A position accuracy better than 2.5 cm has been obtained in 90% of the estimates using only one active anchor at a bandwidth of 2GHz and robustness against non-line-of-sight situations has been demonstrated

Experimental Characterization of System Parameters for Ranging in IEEE 802.15.4a using Energy Detectors

The IEEE 802.15.4a standard for impulse radio ultrawide band (IR-UWB) communication systems defines a ranging scheme which relies on the measurement of the round-trip propagation time of electromagnetic pulses. Accuracy is strongly dependent on the estimation of the timeof-arrival (TOA) of the pulse that is spread in time due to multipath propagation. The major concern therefore is the proper detection of the leading edge. In this work, the ranging capabilities of the standard are analyzed for an energy detector receiver. Emphasis is put on the influence of transmitter and receiver parameters, which are evaluated for a set of measured scenarios. It is shown that sub-meter ranging accuracy can be achieved with fixed parameter settings

Compact broadband frequency selective microstrip antenna and its application to indoor positioning systems for wireless networks

This study presents a low-profile broadband microstrip patch antenna with filtering response. The proposed antenna consists of a rectangular patch and four parasitic gap-coupled elements, two L- and two rectangular-shaped patches. A broadband quasi-elliptic boresight gain response is obtained without using any extra filtering circuits. The input impedance of each radiating element, i.e., driven patch and parasitic elements, is matched to its radiating quality factor and the couplings between patches are optimised for broadband impedance bandwidth with filtering response. Prototype hardware is designed and fabricated on Kappa 438 substrate with a relative permittivity of 4.4 and thickness of 3.2 mm. The antenna exhibits a total size of 25 × 23 × 3.2 mm 3 with relative impedance bandwidth (voltage standing wave ratio<;2) of 60% ranging from 4.4 to 7.8 GHz. The experimental results demonstrate good performance with nearly flat gain and good filtering response. The proposed filtering antenna exhibits low pulse distortion in time domain which makes it a good candidate for location-aware Internet-of-things applications employing the IEEE 802.15.4 ultra-wideband standard. Switchable sector base-station antenna system is studied to demonstrate the capability of this design to enhance the localisation and communication performance of the wireless network

OFDM Air-interface design for multimedia communications

Electrical Engineering, Mathematics and Computer Scienc

Performance Enhancement of a Dual-Signal Receiver System for Simultaneous Reception of two Co-Channel Signals by Applying Error Correction Coding

The Dual-Signal Receiver (DSR) was proposed for simultaneous reception of two narrowband Binary Phase Shift Keying (BPSK) modulated co-channel signals of (slightly) different strength. In this report improvement of the signal cancellation used in the DSR is obtained with Forward Error Correction (FEC) coding. Rather short linear block codes were evaluated using hard and soft decision decoding techniques. Especially soft decision decoding shows large coding gain for a channel with (heavy) cochannel interference and Additive White Gaussian Noise (AWGN). The gain in presence of interference is even greater than the gain achieved in a pure AWGN-channel. The absolute performance is still worse.Applied SciencesElectrical EngineeringTelecommunications and Traffic Control Systems Grou

Semi-Blind Source Separation for Memoryless Volterra Channels in UWB and its Uniqueness

International audienc