Measurements and Verification of an Antenna Pattern-Based Tracking Algorithm at 300 GHz

For wireless communication systems, beam tracking is crucial if the transmitter and/or the receiver is nonstatic. Specifically, for a communication system in the low terahertz frequency range, beam tracking becomes mandatory due to the necessity for highly directive antennas with narrow beams. Therefore, a beam tracking algorithm for horn antennas specified for 300 GHz has been developed. The proposed algorithm uses changes in antenna gain due to the movement of the transmitter and/or receiver. The received power and information about the antenna radiation pattern allow for the prediction of the angle of departure and angle of arrival. Basic verification of the algorithm has already been conducted through simulation and should now be verified under real conditions through measurements. This article presents a measurement campaign conducted with a channel sounding system around 300 GHz. According to the description of the algorithm provided at the beginning of this article, the measurement results are evaluated for both line-of-sight and non-line-of-sight scenarios. The measurement data are used as input for the algorithm to investigate the possibilities of beam tracking in a real system. It is shown that the algorithm can reliably predict angular changes in both line-of-sight and non-line-of-sight cases. With an accuracy of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 1<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula>, angular changes of up to 20<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> can be tracked using information from four different transmitter and receiver antenna combinations. Even higher angular ranges, up to 70<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> in the line-of-sight case and 45<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> in the non-line-of-sight case, can be tracked if the accuracy value is increased to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 4<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula>. The proposed algorithm has, thus, been verified both through simulation and real measurements.