Ray-tracing-based mm-wave beamforming assessment

The use of large-size antenna arrays to implement pencil-beam forming techniques is becoming a key asset to cope with the very high throughput density requirements and high path-loss of future millimeter-wave (mm-wave) gigabit-wireless applications. Suboptimal beamforming (BF) strategies based on search over discrete set of beams (steering vectors) are proposed and implemented in present standards and applications. The potential of fully adaptive advanced BF strategies that will become possible in the future, thanks to the availability of accurate localization and powerful distributed computing, is evaluated in this paper through system simulation. After validation and calibration against mm-wave directional indoor channel measurements, a 3-D ray tracing model is used as a propagation-prediction engine to evaluate performance in a number of simple, reference cases. Ray tracing itself, however, is proposed and evaluated as a real-time prediction tool to assist future BF techniques

Real-time MIMO channel sounder for emulation of distributed ultrawideband systems

This paper introduces an ultrawideband (UWB) channel sounding system. Its novel architecture allows real-time measurements of multiple time-variant radio propagation channels in different ultrawide frequency bands. Its architecture allows emulation of multiuser systems, sensor networks, localization systems, and distributed MIMO radar systems. The sounder uses a maximum length binary sequence (MLBS) excitation signal and correlation processing in the receiver. Its synchronous multichannel operation is supported by excellent timing stability and low power consumption of miniature size modules based upon custom integrated SiGe circuits. The paper describes the architecture, design, calibration, basic parameters, and application examples of the sounding system

Der 60 GHz Indoor-Funkkanal - Herausforderungen menschlicher Abschattung

Driven by the ever increasing capacity of storage devices and HD video streaming applications, there will be a strong demand for wireless multi-Gbps consumer applications soon. Due to its large available bandwidth and the high allowed transmit power, the unlicensed frequency range around 60 GHz is proving ideal for the realization of such systems. During the development process of 60 GHz multi-gigabit wireless systems, a detailed knowledge of the radio channel is essential. Taking into account research gaps, this dissertation makes a significant contribution to knowledge in the field of 60 GHz channel characterization. The focus is on human shadowing and its influence on the channel characteristics, which leads to a high and time-variant path loss. In order to provide realistic results, sophisticated radio channel models are required for the 60 GHz range. In particular, they should include information in the spatial domain at the receiver and the transmitter as well as take into account time-varying human shadowing. The angular information is necessary in this case to evaluate smart antenna systems. Such comprehensive models are not yet available and therefore represent the major outcome of this dissertation.Wegen seiner großen verfügbaren Bandbreite und der hohen erlaubten Sendeleistung erweist sich der unlizensierte Frequenzbereich um 60 GHz als hervorragend geeignet für die Realisierung drahtloser Multi-Gigabit-Kommunikationssysteme. Während des Entwicklungsprozesses solcher Systeme ist eine detaillierte Kenntnis des Funkkanals unerlässlich. Unter Berücksichtigung offener Fragestellungen leistet die vorliegende Dissertation einen wesentlichen Beitrag zum Wissensstand auf dem Gebiet der 60-GHz-Kanalcharakterisierung. Im Vordergrund steht dabei die Abschattung durch Personen, die bei Trägerfrequenzen um 60 GHz zu einer hohen und gleichzeitig zeitvarianten Funkfelddämpfung führt. Um realistische Ergebnisse zu liefern, sind im 60-GHz-Bereich komplexe Funkkanalmodelle erforderlich, die insbesondere Winkelinformationen am Sender und Empfänger enthalten und die zeitvariante Abschattung durch Personen berücksichtigen sollten. Beides ist notwendig, um intelligente Antennensysteme evaluieren zu können. Solche umfassenden Modelle sind bisher nicht verfügbar und stellen deshalb das wesentliche Ziel dieser Dissertation dar

Der 60 GHz Indoor-Funkkanal - Herausforderungen menschlicher Abschattung

Driven by the ever increasing capacity of storage devices and HD video streaming applications, there will be a strong demand for wireless multi-Gbps consumer applications soon. Due to its large available bandwidth and the high allowed transmit power, the unlicensed frequency range around 60 GHz is proving ideal for the realization of such systems. During the development process of 60 GHz multi-gigabit wireless systems, a detailed knowledge of the radio channel is essential. Taking into account research gaps, this dissertation makes a significant contribution to knowledge in the field of 60 GHz channel characterization. The focus is on human shadowing and its influence on the channel characteristics, which leads to a high and time-variant path loss. In order to provide realistic results, sophisticated radio channel models are required for the 60 GHz range. In particular, they should include information in the spatial domain at the receiver and the transmitter as well as take into account time-varying human shadowing. The angular information is necessary in this case to evaluate smart antenna systems. Such comprehensive models are not yet available and therefore represent the major outcome of this dissertation.Wegen seiner großen verfügbaren Bandbreite und der hohen erlaubten Sendeleistung erweist sich der unlizensierte Frequenzbereich um 60 GHz als hervorragend geeignet für die Realisierung drahtloser Multi-Gigabit-Kommunikationssysteme. Während des Entwicklungsprozesses solcher Systeme ist eine detaillierte Kenntnis des Funkkanals unerlässlich. Unter Berücksichtigung offener Fragestellungen leistet die vorliegende Dissertation einen wesentlichen Beitrag zum Wissensstand auf dem Gebiet der 60-GHz-Kanalcharakterisierung. Im Vordergrund steht dabei die Abschattung durch Personen, die bei Trägerfrequenzen um 60 GHz zu einer hohen und gleichzeitig zeitvarianten Funkfelddämpfung führt. Um realistische Ergebnisse zu liefern, sind im 60-GHz-Bereich komplexe Funkkanalmodelle erforderlich, die insbesondere Winkelinformationen am Sender und Empfänger enthalten und die zeitvariante Abschattung durch Personen berücksichtigen sollten. Beides ist notwendig, um intelligente Antennensysteme evaluieren zu können. Solche umfassenden Modelle sind bisher nicht verfügbar und stellen deshalb das wesentliche Ziel dieser Dissertation dar