Measurement of 2x2 LoS MIMO Terahertz Channel

TL;DR

This study measures the capacity of a 2x2 LoS MIMO channel at terahertz frequencies, revealing practical limitations and conditions for achieving high capacity despite theoretical predictions.

Contribution

It provides empirical measurements of terahertz MIMO channel capacity at multiple frequencies, highlighting the impact of signal asymmetry and attenuation on real-world performance.

Findings

Channel capacity exceeds 12 bps/Hz at 460 GHz with sub-optimal spacing

Asymmetric signal strengths reduce practical channel capacity

Maintaining adequate receive signal levels is crucial for high capacity

Abstract

This paper examines the performance of a 2x2 Line of Sight (LoS) Multiple Input Multiple Output (MIMO) channel at three terahertz frequencies-340 GHz, 410 Ghz, and 460 GHz. While theoretical models predict very high channel capacities, we observe lower capacity which is explained by asymmetric transmit-to-receive signal strengths as well as due to signal attenuation over longer distances. Overall, however, we note that at 460 Ghz, channel capacity of higher than 12 bps/hz is possible even at sub-optimal inter-antenna spacings (for different distances). An important observation is also that we need to maintain appropriate receive signal levels at receive antennas in order to improve capacity.