基于GBaud/子载波的偏移正交幅度调制(offset-QAM)多载波系统不仅可以提供可重构光网络需要的速率精细度，还可以优化非线性传输性能。当前offset-QAM多载波系统中的相干接收技术研究并没有考虑高效可重构光网络的特有需求，即尽量降低接收机对波长/路径切换的响应时间。本项目将研究适合高效可重构光网络的接收方案：拟通过提取和反馈色散引起的各种效应的核心参数，实现路径切换后所需要的快速色散估计和补偿；拟采用独立元/主元分析的方法，估计和补偿波长切换后的不稳定频率和相位噪声；拟采用循环变换扩频的方法，提高对波长选择开关在路由中产生的滤波/串扰的鲁棒性。我们将集成各技术研究接收机的整体优化，并在基于传输回路的光通信实验中验证。申请人作为offset-QAM多载波技术在光通信领域的开拓者之一，有扎实的基础和足够的能力实现本项目的研究目标。

Offset quadrature amplitude modulation (offset-QAM) multicarrier systems based on GBaud/subcarrier can not only provide the fine bandwidth granularity in reconfigurable optical networks, but also optimize the nonlinear transmission performance. Current researches on coherent receiver technologies in offset-QAM multicarrier systems do not consider the specific needs in reconfigurable optical network, that is, to minimize the response time of the receiver to wavelength/path switching. In this project, we will investigate the receiver designs suitable to efficient reconfigurable optical networks. We will achieve fast dispersion estimation and compensation required after path switching, by extracting and feeding back key parameters of dispersion-induced effects; study independent- and principal-component-analysis based methods to estimate and compensate the frequency instability and phase noise after wavelength switching; investigate circulant transform spreading to improve the robustness to wavelength selective switch induced filtering/crosstalk in networking routing. We will integrate the proposed technologies for overall receiver optimization, and verify the designs in optical transmission experiments based on the re-circulating loop. As one of pioneers of the offset-QAM multicarrier technology in optical communications, the applicant have the solid foundations and sufficient capability to achieve the objectives of the project.