Alien crosstalk mitigation in vectored DSL systems for backhaul applications

Abstract

The performance of digital subscriber line (DSL) systems, such as ADSL and VDSL is limited by crosstalk. Suppression of in-domain far-end self crosstalk using vectoring technology enables very high bidirectional data rates over twisted-pairs of copper wires. However, the performance of vectored DSL systems is severely degraded in the presence of alien or out-of-domain crosstalk that arises from sources that lie outside the vectored DSL system and share the same cable binder. In this paper, we propose a practical, non-iterative, high performance algorithm for alien crosstalk mitigation. Simulation results and complexity analysis corresponding to a vectored VDSL2 system in presence of alien crosstalk are presented to illustrate the significant performance gains of the proposed algorithm and its low implementation complexity.

An Empirical Rate Balanced Alien Xtalk Mitigation Method for G.fast Systems

“…A similar behavior is observed in the AXT mitigation methods, in which the rates of some lines achieve greater rates than other [10], [11], [12]. In [10] and [11], the lines are benefited distinctly due to the decision feedback structure, which provides more prediction taps for the last user, thus increasing the AXT mitigation, and, consequently, providing more rates for these lines. Conversely, in [12] the first lines appreciate the higher rates, because in this method the gains of each line are the diagonal elements of the upper-triangular matrix of a QR decomposition [13].…”

“…The majority of the multiline AXT mitigation methods are based on steps in which the decoding is carried out iterativelly, in which the next lines (here we assume that the lines are organized in some order) need the information of previous lines to be decoded [10], [11], [12]. This structure allows the lines to share information and then the process is boosted.…”