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Accurate characterization of spatial multipath channels at millimeter wave bands has gained significant interest both in industry and academia. A channel measurement was conducted at three different frequency bands, i.e., 2 − 4, 14 − 16, and 28 − 30 GHz in a line-of-sight (LOS) and an obstructed-LOS (O-LOS) scenarios in an empty room environment. A vector network analyzer connected to a virtual uniform circular array and to a rotational directional horn antenna was used in the measurements, respectively. Angle-of-arrivals and delay-of-arrivals of the multipath components were obtained from the measurements for the three frequency bands. Room electromagnetic properties for the three different frequencies at different propagation scenarios were investigated as well.

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In this article, a novel vector network analyzer (VNA)-based ultrawideband (UWB) channel sounder using radio-over-fiber (RoF) techniques is presented. Benefiting from the usage of optical fiber cable, the measurement range and the dynamic range are significantly increased compared with the conventional coaxial-based VNA system. Specifically, using RoF increases the dynamic range to a maximum of 112 dB at 30 GHz for the back-to-back connection with an optical fiber cable of length 300 m. Moreover, a state-of-the-art phase compensation scheme using optical circulators is proposed for the first time. The novel scheme renders the channel sounder immune to stochastic phase changes in the optical fiber cable due to thermal changes and mechanical stress, thus permitting the remoting of virtual antenna arrays. The proposed channel sounder is experimentally validated in back-to-back measurements, an anechoic chamber, and practical indoor scenarios. The indoor channel measurements are conducted using a virtual uniform rectangular array (URA) at the millimeter-wave (mm-wave) band from 26.5 to 30 GHz. The measured results demonstrate the developed channel sounder's capability to perform UWB large-scale antenna array measurements with a long measurement range.

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This work investigates the variation in the Mean Effective Gain (MEG) for a large number of test persons in order to find how much the difference in anatomy and persons who wear glasses etc. changes the MEG (i.e. the received signal power with respect to a reference). The evaluation was carried out in a typical GSM-1800 urban micro cell with the base station located outdoor approximately 700m from the mobile. The mobile was located in office like environments. Peak variations in the MEG among different persons of more than 10 dB were found and the difference between "no person present" and a person present is on the average 3 dB for a directive patch antenna, 6dB for a whip antenna and 10 dB for a helical antenna.

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Standardization work for MIMO OTA testing methods is currently ongoing, where a multi-probe anechoic chamber based solution is an important candidate. In this paper, the probes located on an OTA ring are used to synthesize a plane wave field in the center of the OTA ring. This paper investigates the extent to which we can approach the synthesized plane wave in practical measurement systems. Both single plane wave with certain AoA and multiple plane waves with different AoAs and power weightings are synthesized and measured. Deviations of the measured plane wave and the simulated plane wave field are presented in terms of phase and power. Possible reasons for the deviations are also investigated.