Dynamic partial crosstalk cancellation resource allocation algorithms for DSL access networks

Abstract

Earlier work on crosstalk mitigation techniques for DSL access networks has focused on physical layer transmit rate maximization or transmit power minimization through static resource allocation, i.e., static allocation of transmit power and/or computational complexity to the individual user in the network. However, such static resource allocation does not allow to consider upper-layer metrics such as network throughput, stability and delay performance. In this article, we develop a set of dynamic resource allocation algorithms for linear zero-forcing partial crosstalk cancellation that allow to include these upper-layer metrics, so as to dynamically allocate computational complexity to the individual users. A first algorithm focuses on preserving dynamic transmission queueing stability while maximizing the transmit rates. This algorithm is then extended towards budget adaptive algorithms, which improve resource efficiency, so as to obtain a trade-off between delay performance and resource consumption. The improved stability and resource efficiency of the proposed algorithms are verified by simulations.

A flexible and real-time constrained controller for sparse linear zero-forcing based DSL vectoring

“…Finally, we wish to highlight that these dynamic schemes are all much more computationally efficient than previously proposed fixed cancellation tap budget approaches [3][4] [5], which use a total system budget of 30%. From Figure 4, we can derive that the average number of allocated cancellation taps is only 9.5% for our new scheme, which corresponds to an improvement of 68%.…”

“…These works however consider a static resource allocation approach. Research work on transitioning from a static to a dynamic allocation of vectoring resources has been presented in [5][6] [7]. These works however only consider the past user behaviour in terms of accumulated queue loads, whereas in this paper future user demands and flexible fixed data rates are considered.…”