With the deepening of 6G communication research, the Terahertz (THz) frequency band has become key to achieving Tbit/s transmission rates due to its extremely wide spectrum resources. However, terahertz signals face severe path loss during space transmission, and place stringent requirements on the real-time performance and bandwidth of baseband processing. This solution is jointly launched by Wuhan Lumiere Electronics and Suzhou Vuba Electronics, utilizing the high-performance processing capabilities of the USRP-LW X410 software-defined radio platform, combined with a high-precision terahertz frequency conversion front-end, to build a demonstrable and secondary-development-ready 6G HD video wireless transmission system.

System Architecture and Link Design

The solution builds a high-bandwidth, low-latency, and high-reliability video transmission system based on the USRP-LW X410 software-defined radio platform and the terahertz frequency conversion front-end. The system adopts OFDM modulation and sub-harmonic mixing technology, shifting the intermediate frequency (IF) signal to the terahertz band through a local oscillator (LO) frequency multiplication link, effectively countering path loss in high frequency bands to achieve over-the-air wireless transmission of HD video.

Figure 1 System Architecture

Transmission Link (TX)

The host computer captures video signals via a camera and transmits them to the USRP-LW X410 through a 10GbE interface. The USRP-LW X410 completes OFDM baseband processing and digital modulation, outputting an IF signal. This IF signal, together with the LO signal source, is fed into the up-converter, and shifted to the 110–500 GHz band after frequency multiplication. The terahertz signal output from the up-converter passes through a bandpass filter to suppress spurious signals, a power amplifier to compensate for losses, and is finally radiated into free space by a high-gain horn antenna.

Reception Link (RX)

The terahertz antenna receives the space signal, which is amplified by a low-noise amplifier and filtered by an FFB bandpass filter to remove out-of-band interference. It is then fed into the down-converter together with the LO signal provided by the same LO signal source, converting it back to IF. The IF signal enters the USRP-LW X410 to complete OFDM demodulation and video recovery, finally displaying the reconstructed picture on the host computer.

Solution Composition and System Specifications

Core Hardware

(1) USRP-LW X410

As a professional wireless equipment manufacturer, Lumiere Electronics provides the USRP-LW X410, a high-performance four-channel software-defined radio platform responsible for baseband signal processing and IF generation in the terahertz video transmission system. Based on the Xilinx Zynq UltraScale+ RFSoC chip, this platform provides 4 independent transceiver channels, with each channel supporting 400MHz instantaneous bandwidth and a frequency coverage of 1MHz-7.2GHz, equipped with dual 10/100 GbE high-speed data interfaces. This SDR implementation empowers the system with powerful data processing capabilities and flexible scalability; whether changing modulation methods, adjusting transmit power, or adapting to different terahertz frequency bands, it can be quickly defined through software.

Figure 2 Lumiere Electronics USRP-LW X410

(2) Terahertz RF Front-End

The terahertz RF front-end is provided by Vuba Electronics, consisting of an up-converter, bandpass filter, power amplifier (PA), low-noise amplifier (LNA), and down-converter. It supports an RF coverage of up to 500GHz, completing high-frequency signal shifting, filtering, and power amplification.

Vuba Electronics' FUC/FDC series up/down-converters provide a frequency range of 40-500GHz (the 110–500GHz customized terahertz model is selected for this solution). Utilizing a structure where the LO frequency multiplication drives a sub-harmonic mixer or a balanced mixer, it features good harmonic suppression, low conversion loss, wide IF bandwidth, and ease of use.

Figure 3 Vuba Electronics FUC/FDC Series Up/Down-Converters

(3) LO Mixing and Antenna System

LO Mixing System: Configured with a high-precision local oscillator (LO) signal source, which connects directly to the mixing ports of the up/down-converters for frequency shifting; meanwhile, it provides a unified frequency reference for both transmitting and receiving ends, ensuring system coherence and phase stability in high frequency bands.

High-Gain Antenna System: Equipped with a horn antenna with a gain of $\ge 25 \text{ dBi}$, fighting against space propagation loss through narrow-beam directional transmission.

Software Implementation

The system software is developed based on Ubuntu and GNU Radio, using OFDM modulation to achieve real-time over-the-air video transmission. The transmitting end captures the H.264 video stream via GStreamer, feeds it into GNU Radio to complete encoding, modulation, IFFT, and cyclic prefix addition, and then transmits it via the USRP-LW X410; the receiving end completes synchronization, FFT demodulation, and decoding through GNU Radio, recovering the video stream to be played by GStreamer. (Reference can be made to Case Introduction - Open Source Tool! Utilizing USRP-LW Products and GNU Radio to Implement a Video Transmission System Platform)

System Parameters

This solution supports multiple frequency bands within 110–500 GHz, and the typical system parameters are as follows:

System Demonstration

The physical appearance of the core hardware equipment involved in this solution (USRP-LW X410, LO signal source, terahertz up/down-converters, high-gain antenna, etc.) is shown in the figure:

Figure 4 Experimental Platform Demonstration

Application Scenarios

This solution is mainly applicable to the following research and testing fields:

• 6G Ultra-High-Speed Communication Pre-research: Validating the wide-bandwidth transmission capability of the terahertz frequency band.

• Space High-Speed Communication: Simulating terahertz data transmission in inter-satellite / satellite-to-ground links.

• Space-Air-Ground Integrated Networks: Testing the feasibility of large-capacity data backhaul.

• Ultra-HD Multimedia Systems: Supporting wireless transmission validation for 4K/8K video.

Terahertz Track Partner -- Suzhou Vuba Electronics

Suzhou Vuba Electronics Technology Co., Ltd. focuses on the R&D and production of millimeter-wave and terahertz universal components, serving fields such as public safety, future communications, industrial sensing, and scientific research. It promotes the localization of core products to create universal, miniaturized, and serialized products. The company's core team comes from well-known institutions in the industry, possessing over twenty years of experience in microwave circuit and electronic equipment R&D, and carries out talent cooperation in the terahertz field with top domestic universities. It has built a Class 10,000 micro-assembly cleanroom, possessing complete capabilities for product assembly, tuning, and testing. Driven by technological innovation and guided by customer needs, the enterprise is dedicated to building a world-renowned millimeter-wave and terahertz brand, contributing Chinese technology to global industrial development.