Sebastian Stern

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—In this paper, lattice-reduction-aided and integer-forcing equalization are contrasted. In both approaches, the determination of an integer matrix is essential. The different criteria for this calculation available in the literature are summarized in a unified way. A new factorization algorithm for obtaining the integer matrix is proposed. Via extensive(More)
Lattice-reduction-aided (LRA) equalization techniques have become very popular in multiple-input/multiple-output (MIMO) multiuser communication as they obtain the full diversity order of the MIMO channel. For joint transmitter-side LRA preequalization or precoding on the broadcast channel, the signal constellation is required to be periodically extendable,(More)
Lattice-reduction-aided preequalization (LRA PE) is a powerful technique for interference handling on the multi-user multiple-input/multiple-output (MIMO) broadcast channel. However, recent advantages in the strongly related field of compute-and-forward and integer-forcing equalization have raised the question, if the factorization task present in LRA PE is(More)
—In this paper, a new class of space-time block codes is proposed. The new construction is based on finite-field rank-metric codes in combination with a rank-metric-preserving mapping to the set of Eisenstein integers. It is shown that these codes achieve maximum diversity order and improve upon existing constructions. Moreover, a new decoding algorithm for(More)
—Lattice-reduction-aided preequalization or precod-ing are powerful techniques for handling the interference on the multiuser MIMO broadcast channel as the channel's diversity order can be achieved. However, recent advantages in the closely related field of integer-forcing equalization raise the question, if the unimodularity constraint on the integer(More)
We present a new approach for assessing the instantaneous power distributions of the continuous-time transmit signal (i.e., after pulse shaping) in single- and multi-carrier transmission schemes. On the one hand, an efficient calculation of the distribution for single-carrier signals via the fast Fourier transform (FFT) is given. On the other hand, tight(More)
—In this paper, equalization and precoding in multiuser multiple-input/multiple-output (MIMO) relaying systems are considered. In particular, the user devices are connected to relays or small base stations which only cover small areas, so-called small cells. Via wireless backhaul, the relays are in turn connected to a central base station, forming a two-hop(More)
Angespornt durch Social-Media-Pioniere im privatwirtschaftlichen Bereich, unternimmt auch der öffentliche Sektor erste Schritte einer gezielten Nutzung. Am Beispiel des Arbeitsmarktmonitors der Bundesagentur für Arbeit zeigt der Beitrag exemplarisch die Bedeutung und Nutzung von Social Media in öffentlichen Einrichtungen auf. Dabei werden Erfolgsfaktoren(More)