Sounding

The HyEff channel sounder is a high‑performance measurement system developed for characterizing complex radio propagation environments, particularly for MIMO (multiple‑input-multiple‑output) wireless channels. It enables precise measurement of the time‑, frequency‑, and spatial characteristics of multipath propagation. By delivering precise and efficient measurement of the spatio‑temporal structure of the radio channel, the HyEff channel sounder bridges the gap between theoretical modeling and real‑world wireless system deployment. Its integration with high‑resolution estimation techniques makes it a key tool for the development of next‑generation communication systems.

The measurement campaign was performed in Cologne (Germany) using a RUSK MIMO channel sounder operating at 2.53 GHz. The fixed transmitter has been mounted on a roof top of an approx. 30m high building whereas the mobile receiver has been set up in a car.

The application of high resolution parameter estimation algorithms requires adequate antenna arrays. Therefore the measurements have been done using a stacked uniform circular array at the base station side (Tx) as well as at the mobile station side (Rx). Both arrays are linear dual polarized.

In order to obtain an antenna independent characterization of the radio channel the high resolution parameter estimation framework RIMAX was used. RIMAX models the channel as the superposition of a deterministic (specular) and a stochastic (dense multipath) part. The deterministic part resembles a multitude of plane waves that are resolvable by the estimator. Each plane wave is hereby described using its time-delay, angle-of-arrival (in azimuth and elevation), angle-of-departure (in azimuth and elevation) and the complex polarimetric path-weight.