FPGA-based optical fiber data transmission accurate time synchronization method

Abstract

The invention relates to an FPGA-based optical fiber data transmission accurate time synchronization method. The method comprises the steps that an optical fiber data sending end takes a uniquely defined COMMA character or data formed by combining the COMMA character and other characters as first data of a packet header of an optical fiber data packet of a frame when a trigger pulse arrives, wherein other information data and control commands follow the first data; an optical fiber data receiving end detects the COMMA character from the received optical fiber data packet, does not utilize theCOMMA character as a serial-parallel conversion alignment sequence for processing in a traditional mode, and only utilizes the uniqueness of the COMMA character as a synchronous trigger command of each frame of optical fiber data; and after detecting the COMMA character, the optical fiber data receiving end correspondingly delays the clock generating the synchronous trigger signal according to theposition of the COMMA character so as to ensure that all the optical fiber data receiving ends recover the synchronous trigger signal of the optical fiber data sending end at the same time accordingto the generation time of the COMMA character.

Description

technical field [0001] The invention relates to a precise time synchronization method based on optical fiber data transmission. In particular, it relates to a precise time synchronization of a large number of digital T / R components in an active antenna array in the field of phased array radars. Background technique [0002] With the development of phased array radar technology, the devices constituting the active antenna array are developing from analog T / R components to digital T / R components and tile sub-arrays. Before revolutionary technological changes, The T / R component is the core component and also the component with the largest number. A large number of digital T / R components need to work simultaneously under precise synchronization time and generate signals with almost no phase difference. In the days of relatively low processing rates, it was most common to send synchronous trigger signals to each component electrically via differential pairs. However, with the i...

AI Technical Summary

Problems solved by technology

However, with the iteration of the chip, there is an uncertain delay in the interface logic inside the early chip. At this stage, the IP cores supported by different types of chips have different degrees of openness.

Whether it is an early chip or a current chip, simply using the IP core provided by the manufacturer cannot complete the time synchronization based on optical fiber data transmission

At present, in phased array radars, the time synchronization of digital T / R components is mostly based on differential electrical signals to transmit synchronous trigger signals. This method has relatively large defects in anti-interference and robustness. Synchronous triggering The signal is easily affected by external electromagnetic interference or clock jitter, which affects the accuracy of time synchronization

However, the method of transmitting time synchronization signals based on optical fiber is limited and the complexity of the use of chip hardware resources makes it too dependent on the openness of chip manufacturers

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