基于光载无线技术的毫米波轨道角动量多维联合调制/解调研究

Study of multi-dimension modulation/demodulation of millimeter wave orbital angular momentum based on radio-over-fiber technology

提出了一种基于光载无线(ROF)技术的W波段涡旋毫米波生成及轨道角动量(OAM)多维联合调制/解调方法。采用ROF技术在光域对微波源进行倍频生成W波段光学毫米波,并通过集成光调制器对光学毫米波的相位和幅度进行调控。通过合理调控圆环天线阵列(CAAs)的辐射毫米波相移,从而实现涡旋毫米波的生成以及状态切换。同时,设计了64阶OAM、幅度和相位的三维联合调制格式,并通过模拟仿真,成功实现了75Gbit/s高阶联合调制信号的调制/解调。研究结果表明,OAM作为一个新的物理维度不仅可以通过复用来实现传输容量密度的提升,同时也可以作为调制手段实现传输容量的提升,在提高无线频谱效率以及保密通信中具有重要的潜在应用价值。

In this paper, we propose a method to generate millimeter-wave （mm-wave） vortex and a com- munication scheme for W-band ram-wave orbital angular momentum （OAM） multi-dimension modula- tion and demodulation based on radio-over-fiber （ROF） technology. We employ ROF technology in the light field to generate W-band optical ram-wave by frequency multiplication, and we regulate phase and amplitude of the optical ram-wave in the integrated optical modulator. By adjusting the phase shift of mm-wave radiated by circular array antennas, we can achieve the generation and state switching of ram- wave vortex. Meanwhile, we also design a 64-order three-dimensional modulation format consisting of OAM,phase and amplitude. And through the simulation,the modulation and demodulation of 75 Gbit/s high order joint modulation signal are realized successfully. The results show that the OAM as a new physical dimension can not only be used to improve the transmission capacity density by multiplexing,but also be used to improve the transmission capacity as a modulation means. And it has important potential application value in improving wireless spectrum efficiency and secure communication.