Long-range VNA-based channel sounder: Design and measurement validation at MmWave and sub-THz frequency bands

With the increasing demand for high bandwidthwireless communication systems, and with a congested spectrumin the sub-6 GHz frequency bands, researchers have been lookinginto exploration of millimeter wave (mmWave) and sub-terahertz(sub-THz) frequency bands. Channel modeling is essential forsystem design and performance evaluation of new wirelesscommunication systems. Accurate channel modeling relies onreliable measured channel data, which is collected by high-fidelitychannel sounders. Furthermore, it is of importance to understandto which extent channel parameters are frequency dependent intypical deployment scenario (including both indoor short-rangeand outdoor long-range scenarios). To achieve this purpose, thispaper presents a state-of-art long-range 28 GHz and 300 GHzVNA-based channel sounder using optical cable solutions, whichcan support a measurement range up to 300 m and 600 m inprinciple, respectively. The design, development and validation ofthe long-range channel sounders at mmWave and sub-THz bandsare reported, with a focus on their system principle, link budget,and back-to-back measurements. Furthermore, a measurementcampaign in an indoor corridor is performed using the developed300 GHz system and 28 GHz channel sounding systems. Bothmeasured channels at the 28 GHz and 300 GHz channels areshown to be highly sparse and specular. A higher number ofMulti Path Components (MPC) are observed for the 28 GHzsystem, while the same main MPC are observed for both systems.