Recent advancements in indoor positioning systems are based on infrastructure-free solutions, aimed at improving the location accuracy in complex indoor environments without the use of specialized resources. A popular infrastructure-free solution for indoor positioning is a calibration-based positioning, commonly known as fingerprinting. Fingerprinting solutions require extensive and error-free...

This work describes a complete indoor location system, from its creation, development and deployment. This location system is a capable way of retrieving the position of wireless devices using a simple software solution, no additional hardware is necessary. The positioning engine uses artificial neural networks (ANN) to describe the behaviour of a specific indoor propagation channel. The traini...

Normally, the communication in the earth surface is through electromagnetic or radio waves. But this is not possible in the underwater environments in an efficient way. In underwater environments radio does not work well due to its quick attenuation in water. Hence the acoustic signals are sent using the acoustic channels. If the communication is done with retransmission, it gives rise to the p...

Double-directional is the feature of propagation that is utilized in multiple-input multiple-output (MIMO) systems with antenna arrays at both ends of the radio link. This contribution discusses which information can be derived from measured/estimated directions of arrival (DOAs) and directions of departure (DODs), and establishes a new parameter describing the multipath spread from both linken...

The ITU Radiocommunication Assembly, considering a) that many new short-range (operating range less than 1 km) personal communication applications are being developed which will operate indoors; b) that there is a high demand for radio local area networks (RLANs) and wireless private business exchanges (WPBXs) as demonstrated by existing products and intense research activities; c) that it is d...

This thesis aims at proposing all the possible enhancements for the MultiResolution Frequency-Domain ParFlow (MR-FDPF) model. As a deterministic radio propagation model, the MR-FDPF model possesses the property of a high level of accuracy, but it also suffers from some common limitations of deterministic models. For instance, realistic radio channels are not deterministic but a kind of random p...

A comprehensive simulation of ultra-wideband signal propagation in indoor environments is presented. The simulation is based on time-domain electromagnetic modeling of transmitting and receiving antennas and the analysis of wave propagation through indoor channels using the time-domain uniform theory of diffraction. The antennas are a pair of TEM horns which are modeled as arrays of vee dipoles...