Demonstration of a Photonics-Aided 4600-m Wireless Transmission System in the Sub-THz Band

Due to the burgeoning demand for data transmission rates and capacities, forthcoming wireless communication networks are required to accommodate data rates reaching tens or even hundreds of Gbps per link. Photonics-aided terahertz (THz) wireless systems, supporting ultra-high-speed and long-distance transmission, stand as highly advantageous candidates for future broadband and large-capacity wireless transmission networks. Building upon this background, our paper systematically summarizes and demonstrates a long-distance wireless communication system in the sub-THz band (125–145 GHz) based on photonics-aided technology. Our experiments achieve a maximum signal transmission rate of 200 Gbps in the 125-GHz band with a wireless transmission range of 4,600 m. Specifically, we experimentally demonstrate photonics-aided single-channel and dual-polarization $\bm {2\times 2}$ MIMO 4600-m wireless transmission within the sub-THz band. In our demonstration of single-channel 4600-m wireless transmission, the maximum transmission rate achieved is 60 Gbps for the 135-GHz QPSK signal and 40 Gbps for the 145-GHz QPSK signal. It is noteworthy that the bit error rate (BER) remains below the soft-decision forward error correction (SD-FEC) threshold of $\bm {2.4\times 10^{-2}}$ with a 20% overhead. Further extending our demonstration to $\bm {2\times 2}$ MIMO 4600-m wireless transmission, we achieve transmission rates of 120 Gbps for PDM-QPSK signals and 200 Gbps for PDM-16QAM at 128.75 GHz and 125 GHz respectively. The BER is maintained below the 20% SD-FEC threshold of $\bm {2.4\times 10^{-2}}$. This achievement sets a record-breaking wireless transmission range of up to 920 Gbps$\cdot$km (200 Gbps × 4600 m) at 125 GHz.