Line initialization method, apparatus, and system

Abstract

The embodiment of the invention provides a line initialization method. Data information is not transmitted in data symbol positions in corresponding directions before the acquisition of coefficient matrices (cancellation coefficient matrix and precode coefficient matrix) no matter in the up direction or the down direction. A CO acquires transmission information in all lines in the up direction at first so as to eliminate the crosstalk generated during data transmission in the up direction of all the lines. In this way, it is ensured that no crosstalk exists in the up direction after a return channel of an up error sample is established, so that a crosstalk channel in the down direction can be borne on data symbols transmitted from a CPE to the CO and the CO can calculate and obtain a transmission channel in the down direction of the lines based on crosstalk channel information fed back by the CPE in the down direction. Thus, the down precode coefficient matrix is obtained to eliminate the crosstalk in the down direction. Therefore, services between the CO and the CPE are not affected and influences, caused by joining of a new line, on service data is reduced to the maximum extent.

Description

technical field [0001] The invention relates to the field of data communication, in particular to a line initialization method, device and system. Background technique [0002] Digital Subscriber Line (DSL, Digital Subscriber Line) is a high-speed data transmission technology transmitted on twisted-pair telephone lines, such as UTP (Unshielded Twist Pair). There are multiple DSL lines in the DSL system, and currently a DSL access multiplexer (DSLAM, Digital Subscriber Line Access Multiplexer) usually provides access services for the multiple DSL lines. However, due to the principle of electromagnetic induction, crosstalk (Crosstalk) will occur between the multiple signals connected to the DSLAM. Twisted pair cables have strong crosstalk at high frequencies. To eliminate crosstalk, for example, vectored (Vectored) DSL technology can be used to eliminate far-end crosstalk. [0003] The existing Vectored DSL technology mainly utilizes the characteristic of joint transmission ...

AI Technical Summary

Problems solved by technology

However, as a new generation of DSL technology, G.fast technology adopts the increase of frequency or the enhancement of coupling. When the crosstalk channel is enhanced to a certain extent compared with the direct channel, the effect of precoding the line directly using the P calculated by the above formula It will be significantly worse, so that the crosstalk from the initialization line received by the line in the showtime phase cannot be well offset, so that the SNR (Signal-Noise Ratio, signal-to-noise ratio) of the line in the showtime phase will decrease and may cause bit errors

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