Channel sounding techniques for applications in THz communications: A first correlation based channel sounder for ultra-wideband dynamic channel measurements at 300 GHz

Abstract

THz communications are a promising possibility to achieve data rates around and above 100 Gbit/s in the near future. Nevertheless, for every communication system the knowledge of the typical propagation characteristics is essential for each application scenario. In this paper, currently available channel sounding techniques are briefly reviewed in regard to the proposed applications for THz communications. Finally, a novel correlation-based channel sounder for 300 GHz is presented and evaluated according to the applications scenarios.

A Perspective on Terahertz Next-Generation Wireless Communications

“…Historically, the VNA and SC based methods have been practically more important, being the common approaches in microwave systems where TDS is not commonly available. The development of these methods is now beginning in the terahertz realm [12][13][14][15]21]. Both time-and frequency-domain channel sounders operating between 3 to 110 GHz are summarized in [13], although most of these fall into the 60 GHz and lower frequency range.…”

“…The VNA steps through a range of discrete, narrowband frequency tones swept across the bandwidth of interest and, at each frequency, measures the channel's magnitude and phase response followed by an inverse discrete Fourier transform of the channel transfer function, which results in a complex CIR [13]. With this technique, very precise channel measurements can be achieved in static environments using a VNA with desired frequency resolution [12]. Vector network analyzers are typically utilized in static environments because of the long frequency sweep time across a broad spectrum, which can exceed the channel coherence time [13].…”

“…Vector network analyzers are typically utilized in static environments because of the long frequency sweep time across a broad spectrum, which can exceed the channel coherence time [13]. In addition, hard-wired connections are required for VNA two-port network synchronization that make it more suitable for indoor and short-range measurements [12][13][14]. Hence, it is restricted to one waveguide band at a time and cannot support wideband measurements with mobile transmitters or receivers.…”

“…The terahertz (THz) region has been actively investigated in the literature, enabling a variety of new applications including spectroscopy, sensing, and communications [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22]. There is a wide variety of publications focusing on the frequency range approximately from 300 GHz up to 3 THz, and its fundamental and promising capability as a next technology platform [10,11,23].…”

Turning THz Communications into Reality: Status on Technology, Standardization and Regulation

“…In order to measure dynamic scenarios and enable a less time-consuming measurement procedure a CS is a more favorable option. A CS based on a PN sequence operating at a carrier frequencies of 9, 60 and 300 GHz with 8 GHz bandwidth is described in [12]. This CS has been also used recently to investigate the similarities of spatial channel characteristics at the above mentioned carrier frequencies in a lecture hall [13] and measure the effect of blocking my moving humans [31].…”