Encoding and decoding with differential encoding size

Abstract

In accordance with an embodiment, the method includes determining a second sequence of numbers of digits for encoding the respective integer coefficient values of the first sequence, the second sequence including, as first element, a first number of digits for encoding the first integer coefficient value of the first sequence, and as second and subsequent elements, constrained numbers of digits that are greater than or equal to respective minimum required numbers of digits for encoding the second and subsequent integer coefficient values of the first sequence. The constrained numbers of digits are such that any two successive elements of the second sequence do not differ from each other by more than a given threshold value. The method further includes encoding difference values between the successive elements of the second sequence; and encoding the integer coefficient values of the first sequence using the respective numbers of digits of the second sequence.

Description

TECHNICAL FIELD OF THE INVENTION[0001]The present invention relates to a compression and decompression method and apparatus for efficiently storing and retrieving vectoring coefficients in a Vectoring Processor (VP).TECHNICAL BACKGROUND OF THE INVENTION[0002]Crosstalk is a major impairment for wired communication systems, such as Digital Subscriber Line (xDSL) communication systems.[0003]Crosstalk arise from Electro-Magnetic (EM) interference between neighboring transmission lines, that is to say transmission lines that are in close vicinity over part or whole of their length, such as twisted copper pairs in a cable binder. Far-End Crosstalk (FEXT) is caused by communication signals being transmitted in a given direction, and that interfere at far-end receivers with communications signals traveling along neighboring transmission lines in the same direction. Near-End Crosstalk (NEXT) is caused by communication signals being transmitted in a given direction, and that interfere at near...

AI Technical Summary

Benefits of technology

The present invention provides an efficient compression scheme and apparatus for encoding and decoding coupling coefficient values. The compression scheme involves determining a second sequence of numbers of digits for encoding the first sequence of integer coefficient values, where the second sequence includes a first element and subsequent elements. The second sequence is constrained to have a minimum number of digits greater than or equal to the minimum required for encoding the second sequence elements. The difference values between the elements of the second sequence are not allowed to exceed a given threshold value. The method also involves adjusting the number of digits in the second sequence to ensure that any two elements do not differ by more than a given threshold value. The compression scheme is particularly useful for vectoring processor applications. The invention also provides a decoder for decoding the encoded coupling coefficient values. The technical effects of the invention include improved compression efficiency and reduced processing time for vectoring processor applications.

Problems solved by technology

Crosstalk is a major impairment for wired communication systems, such as Digital Subscriber Line (xDSL) communication systems.

Far-End Crosstalk (FEXT) is caused by communication signals being transmitted in a given direction, and that interfere at far-end receivers with communications signals traveling along neighboring transmission lines in the same direction.

Near-End Crosstalk (NEXT) is caused by communication signals being transmitted in a given direction, and that interfere at near-end receivers with communications signals traveling along neighboring transmission lines in the opposite direction.

Yet, FEXT remains a predominant source of noise for wired communication systems.

However, the amount of on-chip memory is constrained by cost and space considerations, and one has to come up with some lossless and / or lossy compression schemes for reducing the storage requirements of the VP while maintaining a desired level of fidelity for the decompressed coefficients.

More specifically, an overall compression scheme typically includes lossy and lossless portions.

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