Guangtongxin yanjiu (Aug 2024)
Research on E-band Millimeter-wave Long-distance Communication Technology
Abstract
【Objective】E/W band millimeter-wave frequency covers 60~110 GHz, with abundant frequency band resources and potential for high-capacity transmission. Compared with lasers, E/W band millimeter-wave beam is wider, with advantages of directionality, anti-interference and ease of alignment, making it a promising frequency band for long-distance wireless communication at sea. However, the characteristics of near-sea surface channels such as atmospheric absorption and multipath at the sea surface limit the transmission distance of E/W-band millimeter waves, resulting in bottlenecks in E/W-band millimeter wave transmission near-sea surface. This paper focuses on the direction of long-distance millimeter-wave wireless transmission at sea, using microwave photonics technology to propose an ultra-wideband millimeter-wave modulation and demodulation system architecture to improve the millimeter-wave frequency conversion and modulation performance. We then study the optimal high-order modulation format in near-sea surface long-distance transmission systems to achieve high-capacity long-distance transmission.【Methods】The power amplifier in long-distance communication systems can introduce nonlinear distortion to the signal. It analyzes the factors affecting the performance of high-order modulation formats such as Amplitude Phase Shift Keying (APSK) and Quadrature Amplitude Modulation (QAM) due to the nonlinear characteristics of solid-state power amplifiers. The optimal distribution, Euclidean distance and inner and outer radius ratio of 16APSK signals have been studied. By the equivalent power experiments, the nonlinear resistance of 16QAM and 16APSK signals are compared and analyzed.【Results】The millimeter-wave long-distance transmission experiment is carried out for performance investigation. It proves that the APSK modulation format is more suitable for long-distance transmission system than QAM format.【Conclusion】Based on the 16APSK modulation format, the performance of 16 Gbit/s, equivalent 34 km long-distance transmission are achieved in the experiment, providing high-value technical means for long-distance high-capacity transmission at sea.
