H. A. Obeidat

Indoor localization using received signal strength

A comparison between two indoor localization algorithms using received signal strength is carried out. The first algorithm is the vector algorithm; the second is the matrix algorithm. The comparison considered the effects of the reference points, the access point, and the frequency on the accuracy of the localization process. The experiments were carried out using ray tracing software and MATLAB. This paper justifies the use of adopting the matrix algorithm.

Indoor millimetre-wave propagation channel simulations at 28, 39, 60 and 73 GHz for 5G wireless networks

Millimeter-wave indoor propagation characteristics including path loss models and multipath delay spread values for systems using directional and omnidirectional antennas are presented. The performance of the four 5G candidate frequencies, 28 GHz, 39 GHz, 60 GHz and 73 GHz, are investigated in line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios using published real time frequency measurements conducted in indoor environments. Comparisons are made against simulation data obtained from the 3D Ray Tracing Wireless InSite software over Tx-Rx separations of 1.5 m to 62 m. In addition, frequency-dependent electrical properties, such as conductivity-σ and permittivity-ε, of common building materials are incorporated in the simulation. Results show material type influences propagation behavior of mm-waves due to reflections, diffractions and penetrations of walls and objects (obstacles). It is also shown that while both, the received power and delay spread decrease with increasing frequency, the number of ray paths increases.

Channel Estimation for OFDM FFT/DWT in Multi-carrier Modulation Used in Wireless Telemedicine

This paper proposes an OFDM system to be used in the ECG Patient Monitoring System (ECG-PMS) for wireless telemedicine applications. The system needs a level of transmitted power at the patient site, and achieves a high BER performance at the hospital base station. This achieved by implementing a wavelet-based OFDM system that uses channel estimation based on the improved Data-Aided technique called Forward Error Correction coding Decoded Pseudo Pilot (FDPP). The performance of wavelet-based OFDM systems and Discrete Fourier Transform (DFT)-based OFDM system using FDPP-based as well as Hard Decision Pseudo Pilot channel estimation techniques are compared. The system model was studied using MATLAB software in which the average BER was addressed for randomized data, and the difference between the transmitted and received signals provide a measure of the ECG signal quality. A better BER performance achieved by using OFDM-DWT(haar) system than OFDM_FFT system, thus our system requirements achieved successfully.

A load-pull approach to design an optimum load impedance and matching network for class-F RF power amplifier

This paper presents a Load-pull approach to design a fundamental load impedance and independent matching for class-F RF power amplifier high efficiency operation. The output used a transmitting type active integrated antenna. Power amplifier was design and simulated using Cree GaN FET CGH40010F transistor device at 2.62-GHz operating frequency. The performance of the network has improved by 78% power added efficiency at 30dBm output power.

Radio-location techniques under adverse channel conditions

This paper addresses the problem of locating and tracking a low-power beacon signal in an adverse, multipath environment. We present an implementation scheme for a wideband transmission and direction finding system. This approach takes advantage of delay discrimination to improve angle-of-arrival (AOA) estimation in a multipath channel with high levels of additive white Gaussian noise. Frequency offset estimation is complicated by the poor signal to noise ratio (SNR) and represents the most significant challenge for effective operation. The simulation improves the performance of OFDM signal by mitigating the effect of frequency offset synchronization to give error free data at receiver, good angle of arrival accuracy and improved SNR performance.

Design framework for unobtrusive patient location recognition using passive RFID and particle filtering

The remarkable growth in wireless communication technologies in recent times has motivated the synergy between wireless systems and medical sciences for improved healthcare services. Several emerging wireless technologies and approaches have therefore been proposed to achieve various efficient monitoring systems for health-related activities. In this paper, localisation of a patient using the ranging approach of received signal strength from passive RFID was proposed in the form of smart room. The proposed system is modelled based on a three-level intelligent model of transition, signal measurement and location sensing. The measured RSS is analysed using particle filtering algorithm as a means of localising the position of the target in indoor environments. The system was simulated in a test bed environment using wireless insite with satisfactory results. The system is aimed at achieving a non-wearable sensor approach that is unobtrusive and non-invasive for recognition of activity and location of critically-ill patients and the elderly for timely and reliable healthcare intervention.

Performance comparative study between vector and ECOLOCATION algorithms for indoor positioning

A comparative study of performance is conducted between two indoor positioning algorithms described in the Literature, the Vector and Ecolocation algorithms. Both use received signal strength (RSS) to implement a radio frequency fingerprinting technique. The experiment is conducted using commercial ray tracing software called Wireless Insite and Matlab. The Vector algorithm performs better than the Ecolocation algorithm, which suffers heavily from an ambiguity issue. For the Vector algorithm, the median position error was 2.79 m and 90% of errors were less than 5.72 m.

Surface refractivity profile and validation of measurements in Arabian Gulf region

In this paper, long-term meteorological data are measured using six fixed surface weather stations and one radiosonde in the subtropical Arabian Gulf region, in particular United Arab Emirates (UAE). The surface refractivity profiles, Ns, and refractivity extrapolated to sea level, No, obtained from surface meteorological data using both fixed and radiosonde stations are investigated and compared. The monthly and cumulative distributions of dry, wet and net components of Ns and surface meteorological parameters obtained using both fixed and radiosonde stations are also presented and compared. The obtained results are compared with ITU maps for similar propagation parameters showing non-coherence in some cases.