Jens Jelitto

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In this paper a novel link adaptation algorithm is proposed that is capable of adjusting the transmit power level and the data rate jointly to the radio channel conditions. The proposed method relies solely on link quality information available at the transmitter by employing the reception or non-reception of the acknowledgment frames as a measure of the(More)
In this paper an algorithm and rst results from our investigations in automatically learning pronunciation variations from speech data are presented. Pronunciation dictionaries establish an important feature in state-of-the-art speech recognition systems. In most systems only simple dictionaries containing the canonical pronunciation forms are implemented.(More)
Space-time receivers for wireless communication systems offer the possibility to have both TX-and RX-antennas. For a realistic simulation of such systems, a multiple input multiple output (MIMO) spatial channel model is required which reasonably characterizes the space-and time-variant effects of the mobile radio channel. This paper describes a space-time(More)
The high random and sequential I/O requirements of contemplated workloads could serve as impetus to move faster towards storage-class memory (SCM), a technology that will blur the distinction between memory and storage. On the other hand, the volume of digital data being produced is increasing at an ever accelerating pace. Recent technology demonstrations(More)
We examine the issue of scaling magnetic tape-recording to higher areal densities, focusing on the challenges of achieving 100 Gb/in 2 in the linear tape format. The current highest achieved areal density demonstrations of 6.7 Gb/in 2 in the linear tape and 23.0 Gb/in 2 in the helical scan format provide a reference for this assessment. We argue that(More)
IBMS is a concept for future mobile communication systems to provide a large range of data rates with different degrees of mobility. The integration of heterogeneous services and communication systems requires a common Network Access and Connectivity CHannel (NACCH) for basic signaling to provide permanent network access. Smart Antennas are utilized to(More)
The computational and storage demands for the future Square Kilometer Array (SKA) radio telescope are significant. Building on the experience gained with the collaboration between ASTRON and IBM with the Blue Gene based LOFAR correlator, ASTRON and IBM have now embarked on a public-private exascale computing research project aimed at solving the SKA(More)
— The simulation of wireless communication systems with adaptive antennas requires a spatial channel model which reasonably characterizes the time-variant effects of the mobile radio channel. Moreover, it should also incorporate effects such as fading correlation between the antennas. This model should enable the investigation of several aspects of(More)