Abstract
Sub-Terahertz (sub-THz) (i.e., 100-300 GHz) communication
is envisaged as one of the key building blocks
for future communication systems due to its vast unexploited
bandwidth. Knowledge of the radio channel characteristics is
key to the design and development of new radio systems and air
interfaces. Reliable channel sounding is essential to build accurate
and realistic channel models. Virtual antenna array (VAA) has
been a popular channel sounding strategy to obtain accurate
directional characterization due to its low-cost and simple system
implementation. However, this concept has not yet been realized
for sub-THz bands in the state-of-the-art works due to difficulty
in accurate phase control. The measurement range has been
rather limited at sub-THz due to significant signal loss, especially
in the radio frequency (RF) cables, compared to microwave or
millimeter-wave frequencies. In this paper, we focus on vector
network analyzer (VNA)-based channel sounders, highlighting
frequency extension with sub-THz frequency extenders, measurement
range extension with radio-over-fiber (RoF) schemes,
and angular resolution improvement by VAA implementation
with phase-compensation scheme. These techniques enable and
enhance sub-THz channel characterization. The performance
of the proposed long-range phase-compensated sounder is also
experimentally demonstrated by the VAA-based channel measurements
at 100 GHz in an indoor scenario.
is envisaged as one of the key building blocks
for future communication systems due to its vast unexploited
bandwidth. Knowledge of the radio channel characteristics is
key to the design and development of new radio systems and air
interfaces. Reliable channel sounding is essential to build accurate
and realistic channel models. Virtual antenna array (VAA) has
been a popular channel sounding strategy to obtain accurate
directional characterization due to its low-cost and simple system
implementation. However, this concept has not yet been realized
for sub-THz bands in the state-of-the-art works due to difficulty
in accurate phase control. The measurement range has been
rather limited at sub-THz due to significant signal loss, especially
in the radio frequency (RF) cables, compared to microwave or
millimeter-wave frequencies. In this paper, we focus on vector
network analyzer (VNA)-based channel sounders, highlighting
frequency extension with sub-THz frequency extenders, measurement
range extension with radio-over-fiber (RoF) schemes,
and angular resolution improvement by VAA implementation
with phase-compensation scheme. These techniques enable and
enhance sub-THz channel characterization. The performance
of the proposed long-range phase-compensated sounder is also
experimentally demonstrated by the VAA-based channel measurements
at 100 GHz in an indoor scenario.
| Original language | English |
|---|---|
| Journal | I E E E Communications Magazine |
| ISSN | 0163-6804 |
| Publication status | Published - 2023 |