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Due to demographic change, more elderly people have the need to preserve and support mobility by car despite age-related functional limitations. Since accidents by the elderly are primarily caused by age related limitations, and not by careless or irresponsible behavior, it may be beneficial to detect driving impairing conditions. The presented review gives(More)
We show that an analysis of multiwavelength observations of isolated neutron stars based on neutron star atmosphere models can be used not only to evaluate the neutron star eeective temperature, but also to determine chemical composition of its surface. To demonstrate how this new method can be applied to a speciic object, we chose the old isolated neutron(More)
| A multiuser communication system, which combines some advantages of Code Division Multiple Access (CDMA) and Time Division Multiple Access (TDMA), is presented. For the uplink of a cellular mobile communication environment we analyse the properties of this scheme, taking into consideration multipath propagation on mobile radio channels. Applying error(More)
  • U Jetzek, S Br Uck, J Tr, K Hovakimian
  • 2008
| For an asynchronous Direct-Sequence CDMA system two diierent multistage multiuser detection schemes are discussed. Taking into consideration transmission over a frequency-nonselective slowly fading channel one has to cope with the problem of joint data detection and channel estimation. Simulation results assuming a perfect knowledge of the channel(More)
We demonstrate that if A 1 ; :::;Am are symmetric positive semideenite nn matrices with positive deenite sum and A is an arbitrary symmetric n n matrix, then the relative accuracy, in terms of the optimal value, of the semideenite relaxation (P) is not worse than 1 ? 1 2 ln(2m 2). It is shown that this bound is sharp in order, as far as the dependence on m(More)
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