带内全双工系统的线性化光子辅助自干扰消除  

Linearized Photonic-assisted Self-interference Cancellation for In-band Full-duplex Systems

作　　者：陈煜[1] 石泰峡 陈阳[1] CHEN Yu;SHI Taixia;CHEN Yang(Shanghai Key Laboratory of Multidimensional Information Processing,School of Communication and Electronic Engineering,East China Normal University,Shanghai 200241,China)

机构地区：[1]华东师范大学通信与电子工程学院上海市多维度信息处理重点实验室,上海200241

出　　处：《光子学报》2021年第10期310-321,共12页Acta Photonica Sinica

基　　金：国家自然科学基金(No.61971193);上海市自然科学基金(No.20ZR1416100);区域光纤通信网与新型光通信系统国家重点实验室开放课题(No.2020GZKF005)。

摘　　要：针对带内全双工系统中的自干扰问题与有用信号的非线性失真问题,提出一种基于双偏振双驱动马赫曾德尔调制器的自干扰消除及线性度提升方案。包含有用信号和自干扰的接收信号注入该调制器的两个子双驱动马赫曾德尔调制器上臂的射频端口,构建的参考信号注入两个子调制器下臂的射频端口。两个子调制器被分别偏置在最大传输点和正交传输点,分别探测其输出光信号,得到两路电信号。当注入的参考信号和自干扰完全相同时,两路输出电信号中的自干扰可被完全消除。将这两路电信号采样后进行数字域联合处理,即可恢复出不含自干扰和非线性失真的有用信号。此外,提出了一种优化算法用于减少两路电信号功率不匹配导致的失真。通过仿真与实验验证该方案的可行性。实验结果表明,当有用信号为频率为10 MHz和12 MHz、功率为4 dBm的双音信号,自干扰为中心频率为11 MHz、符号率为4 Mbaud的正交相移键控信号时,该结构可以实现约25.6 dB的自干扰消除深度和17.3 dB的三阶交调抑制深度。A linearized self-interference cancellation scheme based on a dual-polarization dual-drive MachZehnder modulator is proposed to cancel the self-interference and reduce the nonlinearity of the signal of interest for in-band full-duplex systems. The received signals consist of the signal of interest and selfinterference. They are injected into the radio frequency ports of the upper arms of the two sub-dual-drive Mach-Zehnder modulators of the dual-polarization dual-drive Mach-Zehnder modulator, while the constructed reference signals are injected into the radio frequency ports of the lower arms. The two subdual-drive Mach-Zehnder modulators are respectively biased at the maximum transmission point and the quadrature transmission point. When the two optical signals from the two dual-drive Mach-Zehnder modulators are detected in two photodetectors,two electrical signals are generated. If the reference signals and the self-interference are the same,the two electrical signals from the photodetectors are selfinterference free. The two self-interference-free electrical signals are sampled and further processed in the digital domain to obtain the signal of interest without self-interference and nonlinear components. In addition,an optimization algorithm to reduce the distortion caused by the power mismatch of the two electrical signals is proposed. The feasibility of this scheme is verified by simulations and experiments. The experimental results show that when the signal of interest is a 4-dBm two-tone signal with frequencies of10 MHz and 12 MHz and the self-interference is a 4-Mbaud quadrature phase-shift keying signal with a center frequency of 11 MHz,a cancellation depth of around 25.6 dB for the self-interference and a cancellation depth of around 17.3 dB for the third-order intermodulation products can be achieved.

关 键 词：微波光子学 带内全双工 自干扰消除 线性度优化 模拟光信号处理 数字信号处理 

分 类 号：TN29[电子电信—物理电子学]