A Non-Stationary Channel Emulator for 6G THz Wireless Channels

To facilitate the deployment of terahertz (THz) communication systems, it is crucial to develop a channel emulator to accurately and reliably evaluate their performance, which can provide a controlled and repeatable channel environment. However, a suitable channel emulator generating a three-dimensional (3D) non-stationary sixth generation (6G) THz geometry-based stochastic model (GBSM) is missing. To construct this emulator, we utilize a field-programmable gate array (FPGA) development platform to enable the construction of a frequency domain non-stationary THz channel emulator. The channel emulator uses band stitching based on the sum of frequency-modulation (SoFM), along with a sine generation algorithm based on the coordinate rotating digital computer (CORDIC). These techniques guarantee the generation of the THz ultra-wideband (UWB) fading channels. We evaluate the performance of the channel emulator by comparing its important statistical properties, such as the frequency correlation function (FCF), spatial cross-correlation function (SCCF), temporal autocorrelation function (TACF), and cumulative distribution function (CDF) of the stationary bandwidth, with the corresponding theoretical channel model. The proposed channel emulator shows good performance.