Positioning Based on Factor Graphs MENSING, Christian; PLASS, Simon
EURASIP journal on advances in signal processing,
2007, Letnik:
2007, Številka:
22
Journal Article
During flight trials over sea and land, AIS signals were recorded by an aircraft in flight level 280 up to 330, which represents the higher altitudes between 8500m and 10000m. These stored data were ...post-processed and analyzed. Within this paper, the approach of data's post-processing is described, the experienced characteristics to be handled, and challenges faced by the nature of overlapping AIS signals at the aircraft are highlighted. Finally, a comparison of detected signals at the aircraft with received AIS signals on-ground is given including the evaluation of the reception footprint of the aircraft in different altitudes. This gives insight in the detection probability by using aircraft in high altitudes for AIS signal detection.
In this paper, an investigation on the potential extension of the Aeronautical Mobile Airport Communications System (AeroMACS) to different operating scenarios is illustrated. We analyze the ...performance of the system during the approach, landing, and takeoff aircraft phases. A novel airport channel model describing the main wireless propagation phenomena of the new aircraft phases is implemented for accessing the performance of AeroMACS in term of error rate, and a detailed synchronization analysis is also provided. The numerical results obtained for the forward link case in the runway and airborne channel scenarios indicates that AeroMACS is able to cope with the new operational phases and its use can be extended beyond airport surface applications.
Wireless communications and navigation have different constraints to cope with. On the one hand, communication systems traditionally aim at high spectral efficiency with specific requirements such as ...low latency and low power consumption. On the other hand, navigation is usually based on the transmission of known data signals at low data rates with fine synchronization capabilities for efficient signal acquisition and tracking. The ICT project WHERE (Wireless Hybrid Enhanced Mobile Radio Estimators) will focus on exploiting the positioning information to enhance communications -and vice versa- within heterogeneous and/or cooperative wireless systems. The paper gives an overview and outlines the upcoming goals of the FP7-ICT project WHERE. The WHERE project is an ICT STREP project involving 14 partners. It started in January 2008 and is running until June 2010.
In this article we identify and describe the requirements and challenges of next generation mobile communications systems. The so-called fourth generation (4G) aims at throughput rates of more than ...100 MBit/s outdoors with high mobility and 1GBit/s indoors. This requires new advanced techniques in the air interface of such a system. We outline new possible techniques and introduce a future basic physical layer concept. The adaptivity to the channel of all the modules in such a possible concept is highlighted. Since the needed large bandwidth for high data rates is a very valuable resource, future communications systems need a high spectrum flexibility. Furthermore, 4G systems will face severe inter-cell interference scenarios that have to be tackled. Both challenges, i.e., spectrum flexibility and inter-cell interference, are discussed in more detail.
The wireless standards 3GPP Long Term Evolution (LTE), WiMAX, IEEE 802.11a/n, and DxB have in common that they apply the spectrally efficient multi-carrier modulation in order to achieve very high ...rate data transmission. This trend is expected to continue in the future with the development of the next generation of mobile wireless communications under the IMT-Advanced standardization activities. Additional measures like advanced coding, spreading, and MIMO are combined with multi-carrier transmission to further enhance the efficiency of future systems. The aim of Multi-Carrier Systems Solutions 2009 is to edit the ensemble of the newest contributions and research results in this field that have been presented during the 7th International Workshop on Multi-Carrier Systems Solutions (MC-SS 2009), held in Herrsching, Germany.
We recall the principles of cyclic delay diversity (CDD) and discuss the properties and impact of this transmit antenna diversity technology. Different applications motivate variations of the CDD ...principle. This variants are briefly introduced and discussed. We show the application to several types of wireless systems, in particular terrestrial digital video broadcasting, cellular mobile radio communications systems and a wireless communications system using adaptive bit loading. Simulation results show the benefits of CDD for these kind of systems.
