Development of a vector channel sounder for UMTS

Summary form only given. The design and selection of next generation radio technologies require detailed description and accurate directional modeling of the mobile radio channel. In order to assist model development, properties like time, frequency, and spatial (angle or DoA) dispersion have to be jointly investigated. Indeed, spatial domain analysis is of great importance for the exploitation of smart antenna technology. The purpose of the paper is to present the activities of the Mobile Radio Communications Laboratory in the area of enhanced measuring techniques of wideband radio channels. The objective is to develop a dynamic vector channel sounder that will allow for spatio-temporal characterization of multi-dispersive wideband channels. Alternative configurations of the equipment, multiple operation scenarios, and finally, some interesting areas for future research are discussed. The requirements for the system configuration are imposed by a theoretical model, which was founded on the fundamental channel model equations in order to include spatial parameters along with frequency and time characterization. These requirements are interpreted in system performance expectation and furthermore in practical specifications which must be met by the individual transmitter and receiver stages. The vector channel sounder under development will be used for UMTS radio channels since the operating frequency is in the area of 2.0 GHz. The operating bandwidth will be switchable with a maximum value of 100 MHz. The paper includes a detailed presentation of the subsystems that compose the sounder and especially the alternative implementations of the probing signal, the receiver antenna array and RF switch, as well as the digital processing part related with the direct down-conversion, correlation, and real-time channel parameter extraction. Finally, an overview of measurement scenarios suitable for the proposed system is presented