E波段毫米波远距离通信技术研究

Research on E-band Millimeter-wave Long-distance Communication Technology

【目的】E/W波段毫米波频率覆盖60~110 GHz,频带资源丰富,具备大容量传输的潜力,与激光相比,E/W波段毫米波波束较宽,兼具方向性、抗干扰性和易于对准的优势,是海上远距离无线通信极具发展潜力的频段。然而,大气吸收和海面多径等近海面信道特征制约了E/W波段毫米波传输距离,导致E/W波段毫米波近海面传输存在瓶颈。文章聚焦海上远距离毫米波无线传输方向,运用微波光子技术提出了超宽带毫米波调制解调和变频系统结构,提高了毫米波变频和调制解调性能,进而研究近海面远距离传输系统中最优高阶调制格式,实现了大容量远距离传输。【方法】针对远距离通信系统中功率放大器会给信号带来非线性失真的问题,文章分析了固态功率放大器非线性特性对幅度相位调制(APSK)和正交幅度调制(QAM)等高阶调制格式性能的影响因素。研究了16APSK信号的最优分布方式、欧式距离和内外径比例,还通过等效功率实验测试,对比分析了16QAM和16APSK信号的抗非线性性能。【结果】实验证明,相对于QAM格式,APSK格式更加适用于远距离传输系统。【结论】文章基于16APSK格式,通过等效功率验证,实现了16 Gbit/s和等效34 km的远距离传输性能指标,为海上大容量远距离传输提供了高价值的技术手段。

【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.