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Abstract The handling of intercell interference at the cell border area is a strong demand in future communication systems to guarantee efficient use of the available bandwidth. Therefore, this paper focuses on the application of iterative intercell interference cancellation schemes in cellular multicarrier code division multiple access (MC-CDMA) systems at the receiver side for the downlink. First, the influence of the interfering base stations to the total intercell interference is investigated. Then, different concepts for intercell interference cancellation are described and investigated for scenarios with several interfering cells. The first approach is based on the use of the hard decision of the demodulator to reconstruct the received signals. This does not require the higher amount of complexity compared to the second approach which is based on the use of the more reliable soft values from the decoding process. Furthermore, the extrinsic information as a reliability measure of this soft iterative cancellation process is investigated in more detail based on the geographical position of the mobile terminal. Both approaches show significant performance gains in the severe cell border area. With the soft intercell interference cancellation scheme, it is possible to reach the single-user bound. Therefore, the intercell interference can be almost eliminated.

This paper covers location determination in wireless cellular networks based on time difference of arrival (TDoA) measurements in a factor graphs framework. The resulting nonlinear estimation problem of the localization process for the mobile station cannot be solved analytically. The well-known iterative Gauss-Newton method as standard solution fails to converge for certain geometric constellations and bad initial values, and thus, it is not suitable for a general solution in cellular networks. Therefore, we propose a TDoA positioning algorithm based on factor graphs. Simulation results in terms of root-mean-square errors and cumulative density functions show that this approach achieves very accurate positioning estimates by moderate computational complexity.

Demands on security, safety, and environmental protection in worldwide shipping are steadily increasing. Shipboard broadcast transponders based on the Automatic Identification System (AIS) can be easily detected close to coastal or waterway areas. Satellite-based AIS receivers detect globally but are limited in high-density traffic areas. This paper investigates the challenges and performance of AIS detection on aircraft at altitudes between 8 500 m and 10 000 m. During flight trials over sea and land, AIS signals were recorded. Post-processing of the recorded data allows the evaluation but also faces challenges due to the nature of overlapping AIS signals at the aircraft. A comparison of detected signals at the aircraft with received AIS signals on the ground is given, including the evaluation of the reception footprint of the aircraft. Finally, a concept for worldwide AIS detection via airliners is presented. The study shows the potential for global complementary surveillance coverage via airliner-based AIS detection. [ABSTRACT FROM AUTHOR]

The Aeronautical Mobile Airport Communications System (AeroMACS) has been developed for future high-rate, secure, and safety enhancing airport communications in the C-band. Although initially designed for ground applications, the relatively large radio coverage area of AeroMACS suggests its potential extension to new operative scenarios wherein a data link is established between the control tower and the aircraft even when the latter is not in contact with the airport surface. An examination is needed for these new applications concerning channel properties, synchronization aspects, and general performance behaviors. In this paper, the possibility of using AeroMACS during the approach, landing, and takeoff phases of an aircraft flight is investigated. After deriving the channel parameters for the new application scenarios, the synchronization and channel estimation algorithms are presented and the overall error rate performance is assessed by means of computer simulations. Our results indicate that AeroMACS is able to cope with the new operational phases and its use can be extended beyond airport surface applications. [ABSTRACT FROM AUTHOR]

This article presents the in-flight demonstration of a new integrated aircraft communications system combining legacy and future radio technologies. This system, developed and validated under real environmental conditions during flight trials, integrates all the aeronautical service domains within a common IPv6-based aeronautical network. The flight trials were held within the framework of the European SANDRA project at Oberpfaffenhofen, Germany, in June 2013. The presented outcomes emphasize the flexibility and scalability of the developed network and demonstrate the seamless service coverage of the given architecture across different airspace domains. [ABSTRACT FROM PUBLISHER]

An introduction is presented in which the editor discusses various reports within the issue on topics including handset localization with high accuracies in 2G cellular mobile radio systems, the impact of interference due to communications systems transmitting in close bandwidths to global navigation satellite systems (GNSS) signals, and GNSS critical environments.