A feedforward timing recovery method and system suitable for high-speed spaceborne optical communication

Abstract

A feedforward timing recovery method suitable for high-speed spaceborne optical communication, comprising the following steps: (1) after sampling a received signal at a frequency higher than twice the symbol rate, estimating a timing error; the timing error refers to the actual sampling The relative time offset of the point relative to the ideal sampling point; (2) According to the timing error estimated in step (1), determine the digital interpolator interpolation coefficient μ k ; (3) interpolation coefficient μ obtained according to step (2) k , perform digital interpolation processing on the sampled signal block; (4) remove redundant sampling points in the data after interpolation processing, and complete the feedforward timing recovery. The present invention can realize feedforward timing recovery with high precision and high stability under the double symbol rate sampling receiving system, and is more suitable for high-speed spaceborne optical communication systems with limited resources and limited resources.

Description

technical field [0001] The invention belongs to the technical field of high-speed spaceborne optical communication reception, and in particular relates to a feedforward timing recovery method and system suitable for high-speed spaceborne optical communication. Background technique [0002] In the process of high-speed spaceborne optical communication, different sources of clocks at the transceiver end cause a certain timing error in the transceiver, and it is necessary to perform timing recovery at the receiving end so that the receiving sampling is performed at the best time. Timing recovery processing can be divided into two types according to the algorithm structure: feedback recovery method and feedforward recovery method. Among them, the commonly used feedback recovery method is to use the detected timing error signal in the current observation data block to drive the digital interpolator to realize the timing recovery of the next observation data block. Due to the feed...

AI Technical Summary

Problems solved by technology

Among them, the commonly used feedback recovery method is to use the detected timing error signal in the current observation data block to drive the digital interpolator to realize the timing recovery of the next observation data block. Due to the adoption of the feedback mechanism, the timing error extraction of this method has a certain delay In the case of high-speed spaceborne optical communication, with the increase of the number of parallel processing channels, the feedback delay increases, resulting in poor timing recovery performance, unable to resist large timing errors

The feed-forward method uses the current observation data block to estimate the offset of the sampling clock, and then realizes the timing recovery of the current observation data block through a digital interpolator. This method has good real-time performance, fast convergence speed, and is easier to process in parallel. Under the condition of noise ratio, the accuracy of sampling clock offset estimation decreases, and the timing recovery performance deteriorates

In addition, in actual spaceborne optical communication applications, the receiving AD sampling clock frequency is usually slightly higher than twice the communication symbol rate, how to accurately remove the redundant sampling points caused by timing errors is also the difficulty of this method

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