Shanghai Jiao Tong University

Huawei Technologies Co., Limited

Guiling Wu

Jianping Chen

Liang Hu

Hao Kai Zhang

Qi Li

Weiwen Zou

Yue Liu

Jiao Liu

Hao Zhang

Min Ding

Jianguo Shen

Zhengtao Jin

Sitong Wang

Yiwei Sun

Xinwan Li

Wenjun Qian

An optical millimeter wave terahertz transfer system and transfer method are disclosed. The device comprises a local terminal, a transfer link, an access terminal, and a user terminal. By using the device in the transfer link, optical signals transferred forward and backward are extracted through optical couplers, and millimeter wave terahertz signals with a stable phase are obtained at any position in the transfer link through optical signal filtering, photovoltaic conversion, microwave filtering, frequency division and optical frequency shift processing. The device and method have the characteristics of high reliability, simple structure, and low implementation cost.

Distributed optical millimeter wave terahertz transfer system and transfer method

An optical frequency transfer device based on passive phase compensation and a transfer method are provided, where the device comprises a local side, a transfer link and a user side. Optical frequency transfer based on passive phase compensation is achieved by simple optical frequency mixing, microwave filtration, and frequency division processing in a passive phase compensation manner, and the device has simple system structure and high reliability.

Optical frequency transfer device based on passive phase compensation and transfer method

System and method for fiber-optic time frequency and data joint transmission, comprising local end, relay nodes, and remote end. In each local end, relay node, and remote end, multiplexing and demultiplexing of time frequency signals, optical supervisory signals, and optical communication data services are performed by CWDM modules and OSC-band wavelength multiplexer/demultiplexers, and processing (transmitting, relaying, receiving) is performed by corresponding processing modules for joint transmission. A sub-band of standard OSC band is used for transmitting time frequency signal so that transmission of optical supervisory signal is not influenced while no extra band resource is occupied with improved utilization of wavelength resources and reduced costs. Wavelengths of time and frequency transfer in both directions in sub-band of OSC band are flexibly selected and combined to meet different requirements; wavelengths are close or same so that bidirectional symmetry of the link is guaranteed to the maximum with improved precision.

System and method for fiber-optic time, frequency and data joint transmission

Microwave photonic vector network analyzer and a method for measuring scattering parameters of a microwave device are provided. The analyzer comprises a microwave source, wherein a signal loading module, an optical sampling module and a signal processing module are sequentially arranged along a signal output direction of the microwave source; an output end of the signal processing module is respectively connected with a control end of the microwave source and a control end of the optical sampling module; and two test ports of the signal loading module are connected with both ends of a device to be tested. The invention realizes direct sampling and frequency conversion for microwave signals, abandons a superheterodyne structure and/or direct frequency conversion structure in the traditional network analyzer, simplifies the structure of the system while improving the measurement frequency range and avoiding image interference, and reduces system complexity, cost and power consumption.

Microwave photonic vector network analyzer and method for measuring scattering parameters of microwave device

A waveform matching based optical digital signal receiving device sequentially comprises an optical arbitrary waveform generator unit, an electro-optic modulator unit, an opto-electric converter unit, an electric filter unit, a sampling and judging module, a digital signal processing unit and a bit-timing extracting module. Accordingly, signal matched filtering, sampling and judgment can be effectively carried out in the optical domain, and the influence of noises on signal reception can be eliminated to the maximum extent, thereby achieving accurate detection and reception of signals. Meanwhile, compared with a conventional electric receiving device, the digital signal receiving device provided by the present invention breaks the limitation of 'electronic bottleneck,' and greatly improves the bandwidth of signal reception, which allows digital signal reception at a higher speed.

Waveform matching based optical digital signal receiving device

A method and system for high-precision long-distance distributed fiber-optic time transfer. The system comprises a first clock source, a first fiber-optic time transfer unit, N relay and user units, M bidirectional optical amplifying units, a second fiber-optic time transfer unit, and a second clock source. Each relay and user unit obtains timing signals synchronized with the first clock source according to time interval between received forward and backward timing signals and realize distributed fiber-optic time transfer while realizing optical-electric-optical relay of forward and backward transmitted optical signals. Bidirectional time signals pass through the same link to ensure maximum symmetry of the main link bidirectional delay; effect of multiple optical amplifications of noise, such as Rayleigh scattering, on stability of fiber-optic time transfer is avoided by optical-electric-optical process; distributed time transfer is realized by bidirectional timing signal time interval received by the relay and user units.

Method and system for high-precision long-distance distributed fiber-optic time transfer

A method and system for high-precision two-way fiber-optic time transfer comprising pre-adjusting, including calculating a local timing signal adjustment amount for a first fiber-optic time synchronization unit and a second fiber-optic time synchronization unit, and the corresponding adjusting. and following steps including the two fiber-optic time synchronization units conducting two-way time transfer based on a time division multiplexing transmission over an optical fiber link. The present invention realizes high-precision fiber-optic time transfer by combining two-way time transfer and bidirectional time division multiplexing technique.

Method and system for high-precision two-way fiber-optic time transfer

A format for modified IRIB-G time code, with added message fields while preserving pulse width coding rule of the standard IRIG-B time code, having a time interval field for carrying time interval between the local time signal and a received time signal, and a user-defined or padded field for carrying user-defined time and/or control messages. An encoding and a decoding methods and devices for high-precision time transfer, where the modified IRIG-B time code carries more messages, and enabling transmission of timing messages and testing messages of two-way time comparison via a single message channel at the same time, which reduces fluctuation due to encoding and decoding manipulation and correlation with working frequencies via exact synchronization between the on-times of the output encoded time code and the transmitted time signal, and between the on-times of the output decoded time signal and the input time code, and improves precision of time transfer.

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Shanghai, China

Guiling Wu