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Generalized frequency division multiplexing (GFDM) is a new digital multicarrier concept. The GFDM modulation technique is extremely attractive for applications in a fragmented spectrum, as it provides the flexibility to choose a pulse shape and thus allows reduction of the out-of-band leakage of opportunistic cognitive radio signals into incumbent frequency space. However, this degree of freedom
Generalized frequency division multiplexing (GFDM) is a new concept that can be seen as a generalization of traditional OFDM. The scheme is based on the filtered multi-carrier approach and can offer an increased flexibility, which will play a significant role in future cellular applications. In this paper we present the benefits of the pulse shaped carriers in GFDM. We show that based on the FFT/I
Codes constructed from connected spatially coupled low-density parity-check code (SC-LDPCC) chains are proposed and analyzed. It is demonstrated that connecting coupled chains results in improved iterative decoding performance. The constructed protograph ensembles have better iterative decoding thresholds compared to an individual SC-LDPCC chain and require less computational complexity per bit wh
Context-aware computing is a typical paradigm of ubiquitous computing and aims to provide context information anywhere and anytime. Context data management which handles gathering, processing, managing, evaluating and disseminating context information is the heart of context-aware system. Context provision and acquisition, thus, become crucial for context-aware computing. In order to decouple appl
Reference attribute grammars (RAGs) have proven practical for gen- erating production-quality compilers from declarative descriptions, as demonstrated by the JastAdd system. Recent results indicate their applicability also to generating semantic services in interactive editors. For use in editors, it is necessary to update the attribution after edit operations. Earlier algorithms based on statical
Designing decorrelated MIMO antennas in small mobile terminals at frequencies below 1 GHz is challenging since more than one antenna tend to excite the single resonant mode available to a typical chassis structure. This challenge increases even further when multiple frequency bands are required from each antenna. Recently, a design framework to obtain efficient and decorrelated MIMO antennas based
The thesis covers different topics related to model predictive control (MPC) and particularly distributed model predictive control (DMPC). One topic of the thesis is gradient-based optimization algorithms for solving the optimization problem arising in DMPC in a distributed manner. The underlying idea is to solve the optimization problem in distributed fashion using dual decomposition, which is a
Abstract in UndeterminedA millimeter-wave (mm-wave) impulse radio is an attractive alternative to existing high-speed mm- wave radio systems because of the potential for a simpler transceiver architecture. This paper studies the feasibility of a mm-wave impulse radio system for home and office use by considering state-of-the- art transceivers and multiple-input multiple-output measured propagation
Evaluation of Specific Absorption Rate (SAR) for multiple antenna systems is becoming important, with the upcoming deployment of LTE-Advanced. In this work, the influence of different antenna locations and antenna types was investigated for stand-alone SAR and simultaneous SAR, to provide some guidelines for antenna design in multi-antenna handsets. For simultaneous SAR, different phase shifts bet
A primary functionality of context aware applications is the retrieval of different types of context data from various context sources and adapting their behavior accordingly. In order to facilitate context aware application development, a context aware middleware must provide an effective context data management and lookup strategy. The use of a traditional index for indexing dynamic context data
Context-aware applications generally need to retrieve various kinds of dynamic context data from a large number of context sources. A middleware managing context sources must provide an efficient context lookup mechanism to ease application development. In this paper, we categorize the context sources as operating spaces and propose semantic peer-to-peer overlays over these spaces to accelerate dy
We compare LDPC block and LDPC convolutional codes with respect to their decoding performance under low decoding latencies. Protograph based regular LDPC codes are considered with rather small lifting factors. LDPC block and convolutional codes are decoded using belief propagation. For LDPC convolutional codes, a sliding window decoder with different window sizes is applied to continuously decode
The concept of “style of thought” or Denkstil is today probably primarily associated with the Polish microbiologist and philosopher of science Ludwik Fleck and his writings from the 1930s. It was however used quite extensively already by Karl Mannheim in his writings on the sociology of knowledge from the 1920s. Quite interestingly, the concept of style of thought was also used twice by Rudolf Car
Abstract in UndeterminedRobustness of distributed routing policies is studied for dynamical networks, with respect to adversarial disturbances that reduce the link flow capacities. A dynamical network is modeled as a system of ordinary differential equations derived from mass conservation laws on a directed acyclic graph with a single origin-destination pair and a constant total outflow at the ori
Abstract—Service Level Agreements (SLA) are considered a good practice not only for IT outsourcing but also for IT management within an organisation. In this paper we study the usage of SLAs in municipal IT management. Municipal IT management traditionally involves a large organisation, often with a low IT maturity, but with high requirements on software quality and information security. In this s
Generalized Frequency Division Multiplexing (GFDM) is a recent multi carrier modulation technique that can provide low out-of-band radiation, which makes it an attractive choice for the PHY layer of cognitive radios operating in fragmented TV white spaces. Primary, incumbent signals can now be protected with a geo-location database query mechanism. Even then, sensing opportunistic users (OU) opera
