NLOS mitigation techniques in GNSS receivers based on Level Crossing Rates (LCR) of correlation outputs

Global Navigation Satellite Systems (GNSS) provide navigation services with a highly precise estimation of the position. First military influenced, the use of satellite-based positioning has gained a lot of interest also in civilian tasks nowadays. Because the GNSS performance has been improved over the years, the state-of-the-art GNSS navigation does include indoor positioning and moving autonomously with help of GNSS. The accuracy, which essentially has to be high, can be disturbed by multipath (e.g. diffraction, reflection, refraction or scattering). A possibility to detect multipath, and possibly to avoid those signals in the position solution, is totally necessary. A non-direct signal, namely Non-Light-of-Sight (NLOS), can lead to low accuracy of the positioning. Therefore, this thesis is dealing with the NLOS detection by using the Level Crossing Rate (LCR), which has been used in electronic communication such as Wifi. The thesis is divided in two parts, including a literature review part, following by a simulation of the developed detection technique. All basic knowledge about this work can be extracted from the literature part. In the simulation section, several tests will be provided, done by Matlab simulations. To perform a realistic GNSS signal, a dynamic Galileo Composite Binary Offset Carrier (CBOC) signal was produced

AN ENERGY EFFICIENT CROSS-LAYER NETWORK OPERATION MODEL FOR MOBILE WIRELESS SENSOR NETWORKS

Wireless sensor networks (WSNs) are modern technologies used to sense/control the environment whether indoors or outdoors. Sensor nodes are miniatures that can sense a specific event according to the end user(s) needs. The types of applications where such technology can be utilised and implemented are vast and range from households’ low end simple need applications to high end military based applications. WSNs are resource limited. Sensor nodes are expected to work on a limited source of power (e.g., batteries). The connectivity quality and reliability of the nodes is dependent on the quality of the hardware which the nodes are made of. Sensor nodes are envisioned to be either stationary or mobile. Mobility increases the issues of the quality of the operation of the network because it effects directly on the quality of the connections between the nodes

AN ENERGY EFFICIENT CROSS-LAYER NETWORK OPERATION MODEL FOR MOBILE WIRELESS SENSOR NETWORKS

Wireless sensor networks (WSNs) are modern technologies used to sense/control the environment whether indoors or outdoors. Sensor nodes are miniatures that can sense a specific event according to the end user(s) needs. The types of applications where such technology can be utilised and implemented are vast and range from households’ low end simple need applications to high end military based applications. WSNs are resource limited. Sensor nodes are expected to work on a limited source of power (e.g., batteries). The connectivity quality and reliability of the nodes is dependent on the quality of the hardware which the nodes are made of. Sensor nodes are envisioned to be either stationary or mobile. Mobility increases the issues of the quality of the operation of the network because it effects directly on the quality of the connections between the nodes