NTT DOCOMO and Rohde & Schwarz joined forces to set up the world’s first ultra-wideband channel sounder for mobile communications above 100 GHz, conducting propagation experiments up to 150 GHz.
The frequency bands from 100 to 300 GHz are expected to enable higher speed and higher capacity communications for the generations of networks beyond 5G. Between 100 and 300 GHz, wider bandwidth is available than the millimeter wave bands currently envisioned for 5G. However, these higher frequencies are strongly affected by people, vehicles, trees and environmental conditions like rain, making it necessary to understand the influence of the environment on the propagation.
Using test and measurement equipment from Rohde & Schwarz, DOCOMO developed a novel ultra-wideband millimeter wave channel sounder to measure propagation characteristics, including
- Propagation loss: the degree of attenuation of the signal.
- Power delay profile: the arrival time of signal.
- Angular profile: an indicator of the spread of radio wave propagation.
The DOCOMO test system was placed in an anechoic chamber, where DOCOMO and Rohde & Schwarz measured the shielding effects of the human body, applying signals up to 150 GHz, as well as the 5G bands in use or proposed.
The test system used the R&S SMW200A signal generator with the R&S SMZ frequency multiplier to generate the millimeter wave signal, with the R&S FSW85 signal and spectrum analyzer and R&S FS-Z170 harmonic mixer used to analyze the received signal. The setup has a scalable analysis bandwidth up to 2 GHz and provides a convenient user interface, displaying the propagation characteristics in real time.