Uplink performance investigations of the service area based beyond 3G system JOINT

The joint transmission and detection integrated network (JOINT) is a novel OFDM-based vNP00 air interface solution for beyond 3G (B3G) mobile radio communications systems WMSL02. JOINT aims at eliminating the multiple access interference (MAI) and improving the system capacity by the application of MIMO techniques applied in the service area (SA) based system architecture. In a SA based structure the intra-SA multiple access interference (MAI) can be easily combated by algorithms like, e.g., joint detection (JD) Kle96,Ver98 in the uplink. The parameters like, e.g., the SA size, the system load and reuse factor show great impacts on the system performances, in terms of the average bit error rate (BER) and the BER statistics. Spectrum efficiency of JOINT is also investigated based on the simulation results

Feasibility Conditions of Interference Alignment via Two Orthogonal Subcarriers

Conditions are derived on line-of-sight channels to ensure the feasibility of interference alignment. The conditions involve choosing only the spacing between two subcarriers of an orthogonal frequency division multiplexing (OFDM) scheme. The maximal degrees-of-freedom are achieved and even an upper bound on the sum-rate of interference alignment is approached arbitrarily closely.Comment: Submitted to ISIT 201

Подход к созданию баз данных, основанный на алгоритмах генерации и идентификации кортежей

Предложена оригинальная модель реляционной базы данных, в основе которой лежит представление доменов в виде деревьев И-ИЛИ. Разработаны оригинальные алгоритмы генерации и идентификации кортежей. Показана возможность существенного сжатия базы данных при небольших значениях мощностей доменов

Ziel-orientierter Entwurf von Multi-hop Medienzugriffsprotokollen

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Die Benutzung von Relais in einem drahtlosen Kommunikationssystem kann unterschiedlichen Zielen dienen: der Erweiterung der Abdeckung oder der Erhöhung der Kapazität einer Zelle, aber auch zur Verbesserung der Energieeffizienz. Zu diesem Zweck müssen unterschiedliche Probleme, z.B. der Wegewahl und Weiterleitung, gelöst werden. Hier wird aufgezeigt, wie sich das Ziel in der Gestaltung eines geeigneten Medienzugriffsprotokolles für drahtlose multi-hop Kommunikationssysteme niederschlägt. Dabei werden die einschlägigen Ergebnisse dreier Projekte – Coverage, ClusterNet und IBMS2 – zusammengefaßt

Interference Mitigation Framework for Cellular Mobile Radio Networks

For today's cellular mobile communication networks, the needed capacity is hard to realize without much more of (expensive) bandwidth. Thus new standards like LTE were developed. LTE advanced is in discussion as the successor of LTE and cooperative multipoint transmission (CoMP) is one of the hot topics to increase the system's capacity. System simulations often show only weak gains of the signal-to-interference ratio due to high interference from noncooperating cells in the downlink. This paper presents an interference mitigation framework to overcome the hardest issue, that is, the low penetration rate of mobile stations that can be served from a cluster composed of their strongest cells in the network. The results obtained from simulation tools are discussed with values resulting from testbed on the TU Dresden. They show that the theoretical ideas can be transferred into gains on real systems