Volume 66, Issue 5-6 -

This paper presents a system proposal for a self-organized cellular network, which is based on the MIMO-OFDM transmission technique. Multicarrier transmission, combined with appropriate beamforming concepts, yields high bandwidth-efficiency and shows a robust behavior in multipath radio channels. Moreover, it provides a fine and tuneable granularity of space-time-frequency resources. Using a TDD approach and interference measurements in each cell, the Base Stations (BSs) decide autonomously which of the space-time-frequency resource blocks are allocated to the Mobile Terminals (MTs) in the cell, in order to fulfil certain Quality of Service (QoS) parameters. Since a synchronized Single Frequency Network (SFN), i.e., a re-use factor of one is applied, the resource blocks can be shared adaptively and flexibly among the cells, which is very advantageous in the case of a non-uniform MT distribution.

Equalization of broadband signals can be efficiently realized in frequency domain. One prominent example is the orthogonal frequency division multiplexing (OFDM) transmission technique. With the introduction of a cyclic prefix and a modulation onto orthogonal subcarriers the equalization can be performed in frequency domain with one tap only. However the extremely high peak to average power ratio of OFDM modulated transmit signals and the demand of linearity inside the signal transmission chain results in a poor energy efficiency at the power amplifier. This paper claims, that as long as a cyclic prefix exists, any receive signal can be equalized in frequency domain. In this paper a transmission scheme with constant envelope is chosen for energy efficiency reasons. Therefore an FSK modulation and gaussian pulse shaping is used to create the transmit signal. Equalization at the receiver is done in frequency domain as known in OFDM. To simplify the equalization, a cyclic prefix is added to the transmit signal as well. This transmission scheme is introduced and evaluated in terms of spectral efficiency and bit error rate (BER) performance in this paper. The comparison is done with a typical OFDM system. In particular the characteristics of a nonlinear power amplifier are considered. It will be shown, that signals with constant envelope such as FSK modulated signals can also make use of an OFDM like equalization procedure with comparable BER performance and spectral requirements.

xDSL systems have to be able to support an always increasing amount of high-rate applications. To make the applications run stably, service providers need to be capable of guaranteeing these high data rates to their customers at a limited amount of available computational complexity usable for crosstalk cancellation. In order to be able to support high data rate targets with a low amount of computational complexity, partial crosstalk cancellation was combined with spectrum management techniques. A selection procedure was found, which jointly chooses the canceled crosstalkers and the transmit powers for each user on each tone by interlacing Iterative Water Filling (IWF) and a newly developed successive crosstalk selection algorithm for partial crosstalk cancellation, which takes into account the data rate requirements of the users. It distributes the available computational complexity in an intelligent way, so that data rate requirements are fulfilled. With the joint procedure savings in computational complexity are achieved.

The radar technology has a long history of over more than one century. In contrast to this its application in the automotive domain is a quite young activity. The enablers of this relatively new research field are presented in this article from a car manufacturers perspective covering aspects of signal processing algorithms, hardware and driver assistance applications.

A highly integrated 24 GHz radar sensor is presented, based on a Radio Frequency Integrated Circuit (RFIC) which was specifically developed for a Frequency Modulated Shift Keying (FMSK) based Radar system design. Antenna, waveform, the Radio Frequency (RF) and Digital Signal Processor (DSP) module, the software design, cost and performance aspects will be described. The significant technical and economical advantages of the implemented Silicon-Germanium (SiGe) Bipolar CMOS (BiCMOS) transceiver are demonstrated. Some automotive and other applications based on this technology and new radar system design will be explained.

The cabin of modern aircraft is subject to increasing demands for fast reconfiguration and hence flexibility. These demands require studies for new network architectures and technologies of the electronic cabin systems, which consider also weight and cost reductions as well as safety constraints. Two major approaches are in consideration to reduce the complex and heavy wiring harness: the usage of a so called hybrid data bus technology, which enables the common usage of the same data bus for several electronic cabin systems with different safety and security requirements and the application of wireless data transfer technologies for electronic cabin systems.

For more than ten years, car-2-x communication has been a major topic of research in the scientific community and an important development focus for the automotive industry. First, this article takes a retrospective look at the evolution of car-2-x and the two different communication paradigms: decentralized car-2-car communication and centralized cellular solutions. Afterwards, a comparison of their technical advantages and limitations is presented, respectively. The result shows that in order to implement safety-relevant applications, car-2-car communication has strong advantages compared to cellular technologies but requires high market penetration. However, its introduction solely for safety applications is difficult since the required penetration will not be achieved until several years after initial deployment. Therefore, car-2-car communication must provide a benefit to the customer, even in the phase of market introduction. For this purpose, the article outlines an approach called SODAD (Segment-Oriented Data Abstraction and Dissemination). It offers a possibility to introduce decentralized vehicular applications with early customer benefit, in order to enable safety applications based on car-2-car communication on a long term.

The objective of this paper is to investigate methods to guarantee the network performance of industrial Ethernet networks by an optimized topology design. The proposed approach differs from former works on network design by taking into account the specific requirements of industrial applications, the Quality of Service (QoS) related features of industrial Ethernet protocols, and the increasing network complexity in the industrial field. A multi-objective variable neighbourhood search algorithm (MOVNS) is presented offering a co-design method of physical topology and logical topology to satisfy the requirements of real-time capability, high reliability, and fast recovery time. The result analysis on simulation test cases shows the proposed algorithm can greatly improve the performance of industrial Ethernet networks at a moderate computational complexity.