Zheng Lizhuo, Zhang Yunhao, Xiao Shilin, Huang Lin, Fang Jiafei, Hu Weisheng
Opt Express. 2019 Feb 18;27(4):4116-4125. doi: 10.1364/OE.27.004116.
In this paper, we propose an adaptive optical self-interference cancellation using regular triangle algorithm for in-band full-duplex systems. By using this algorithm, the manual adjustment of the tunable optical time delay line and attenuator is replaced with the adaptive program to change the delay and attenuation for achieving optimal cancellation point. The adjustment process is simplified as a convex function problem. We choose to attain the optimal cancellation point by directly and continuously sampling the power of the signal after cancellation and in turn adjust the time delay and attenuation according to the algorithm. In this way, the two paths in the self-interference cancellation system are precisely and automatically matched. By using our proposed algorithm, the interference signal over 300-MHz wideband is diminished to the noise floor, attaining 20-25 dB cancellation depth adaptively. Compared with other existing algorithms in both the experiment and simulation, our proposed regular triangle algorithm reaches the optimal point faster with 10-30% less number of samples from the near start region, and lowers 40-60% less number of samples from the farther start region.
在本文中，我们针对带内全双工系统提出了一种使用正三角形算法的自适应光学自干扰消除方法。通过使用该算法，用自适应程序取代了对可调光学时延线和衰减器的手动调节，以改变延迟和衰减来实现最佳消除点。调节过程被简化为一个凸函数问题。我们选择通过直接连续采样消除后信号的功率来获得最佳消除点，然后根据该算法调整时延和衰减。通过这种方式，自干扰消除系统中的两条路径得以精确且自动地匹配。使用我们提出的算法，超过300MHz宽带的干扰信号被降低到本底噪声，自适应地实现20 - 25dB的消除深度。在实验和仿真中与其他现有算法相比，我们提出的正三角形算法从起始区域较近位置达到最佳点的速度更快，采样次数少10% - 30%，从起始区域较远位置采样次数少40% - 60%。
