Method of sampling signal of locating frame head in SDH transmission system

Abstract

The invention discloses a sampling method of aligning frame header signals in SDH transmission system. The method comprises: step 1, the system reference frame header signals sent by clock board are received and the reference frame header signals are processed with two divided-frequency processing. Step 2, the signals processed with the two divided-frequency processing are sampled by system clock. Step 3, the signals obtained from the step 2 are processed with twice clock cycle delay sampling. Step 4, the signals obtained from the twice delay sampling of the step 3 are processed with exclusive or processing and then the amended aligning frame header signals are obtained. In addition to stability, the invention realizes the alignment of the reference frame header signals and the clock. By the mode of the frame header processed by chip on cross board, the invention lightens the pressure of the strict condition for sending out system frame header on the clock board in the SDH system, solving the problems of the cost brought by originally adding the reference frame header of hardware circuit correction system on the clock board and bad effects, etc. effectively, thereby reducing the condition restriction from the SDH system to the system frame header sent out by the clock board.

Description

technical field [0001] The invention relates to a sampling method for positioning frame headers in an SDH transmission system in the communication field, in particular to a sampling method for distorting the positioning frame headers due to long transmission distances. Background technique [0002] In the SDH transmission system, the clock board is responsible for sending periodic system reference frame header signals and system clock signals to the cross-connect board. Alignment mark, the quality of the reference frame header signal received by the cross-connect board determines the alignment of the data stream output of the cross-connect board and the stable quality of work. If the system reference frame header signal received by the cross-connect board is distorted due to problems such as long transmission distance or inter-board interference If (widening or narrowing) cannot change periodically and stably, the data on the cross-connect board may not be aligned, resulting...

AI Technical Summary

Problems solved by technology

[0005] In order to overcome the problems existing in the prior art, the present invention solves the problem of distortion of the system reference frame header in the design of the cross chip, thereby reducing the conditional limitation of the SDH system on the system frame header sent by the clock board

[0006] Specifically, the present invention aims to solve the problem in the prior art that the reference frame header signal is distorted due to the influence of the transmission distance and the working environment, and correct the reference frame header to ensure that the data on the cross-board is aligned for effective processing, eliminating Distortion of Received Reference Frame Header Signals on the Cross-connect Board

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