| 1. |
- Gomes, Ana, et al.
(författare)
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An hybrid evolutionary multiobjective algorithm for multiuser margin maximization in DSL
- 2016
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Ingår i: International Journal of Communication Systems. - : Wiley. - 1074-5351. ; 29:1, s. 194-209
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Tidskriftsartikel (refereegranskat)abstract
- This work describes and proposes the application of evolutionary algorithms on the multiuser spectrum and SNR margin optimization problem for multicarrier systems, such as digital subscriber line. The proposed method is designed such that it takes advantage of special characteristics of the well-known power adaptation techniques and uses them to solve the broader and more challenging problem of multiuser margin adaptation. Simulations show that the proposed method provides Pareto-optimal and diverse solutions when compared to a previous method to solve the same problem. Copyright (c) 2014 John Wiley & Sons, Ltd.
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| 2. |
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| 3. |
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| 4. |
- Lindqvist, Neiva, et al.
(författare)
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Impact of crosstalk channel estimation on the DSM performance for DSL networks
- 2010
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Ingår i: Eurasip Journal on Advances in Signal Processing. - : Springer Science and Business Media LLC. - 1687-6172 .- 1687-6180.
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Tidskriftsartikel (refereegranskat)abstract
- The development and assessment of spectrum management methods for the copper access network are usually conducted under the assumption of accurate channel information. Acquiring such information implies, in practice, estimation of the crosstalk coupling functions between the twisted-pair lines in the access network. This type of estimation is not supported or required by current digital subscriber line (DSL) standards. In this work, we investigate the impact of the inaccuracies in crosstalk estimation on the performance of dynamic spectrum management (DSM) algorithms. A recently proposed crosstalk channel estimator is considered and a statistical sensitivity analysis is conducted to investigate the effects of the crosstalk estimation error on the bitloading and on the achievable data rate for a transmission line. The DSM performance is then evaluated based on the achievable data rates obtained through experiments with DSL setups and computer simulations. Since these experiments assume network scenarios consisting of real twisted-pair cables, both crosstalk channel estimates and measurements (for a reference comparison) are considered. The results indicate that the error introduced by the adopted estimation procedure does not compromise the performance of the DSM techniques, that is, the considered crosstalk channel estimator provides enough means for a practical implementation of DSM.
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| 5. |
- Monteiro, Marcio, et al.
(författare)
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An algorithm for improved stability of DSL networks using spectrum balancing
- 2010
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Ingår i: [Host publication title missing]. - 9781424456369
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Konferensbidrag (refereegranskat)abstract
- The proper management of the signal to noise ratio margin is important for improving the stability of digital subscriber line (DSL) networks and increasing the customer satisfaction regarding services such as triple-play. This work presents a novel algorithm for multiuser margin optimization that benefits from the relationships between power and margin adaptation. The proposed multiuser margin maximization (MMM) is a meta algorithm that repeatedly invokes a spectrum balancing base algorithm. The base algorithm corresponds to a dynamic spectrum management (DSM) algorithm of level one or two, and is responsible for part of the overall spectra optimization procedure. Simulation results illustrate the performance of the proposed algorithm when using two base algorithms: iterative water-filling (IWF) and iterative spectrum balancing (ISB). The results show that the proposed MMM is able to design better noise margins and spectra, providing performance improvements when compared to a previous margin optimization algorithm that is restricted to using DSM level 1 coordination.
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| 6. |
- Moraes, Rodrigo B., et al.
(författare)
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Semiblind Spectrum Balancing for DSL
- 2010
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Ingår i: IEEE Transactions on Signal Processing. - 1053-587X. ; 58:7, s. 3717-3727
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Tidskriftsartikel (refereegranskat)abstract
- Digital subscriber lines (DSLs) technology is vastly used for high-speed data transmission. Crosstalk is one of the main problems in DSL. The research community has done extensive work on how to optimize spectrum allocation across DSL frequencies and mitigate crosstalk, a subject that has been called dynamic spectrum management (DSM). This text presents a novel DSM solution, referred to as semiblind spectrum balancing (2SB). 2SB performs an optimization process with a virtual line, a fictitious line that represents to each user the damage it causes for all other users. With the aid of message exchanges between modems and a central agent, the method will adjust the virtual line's parameters so that it represents the real crosstalk scenario in the binder. In this paper, we provide the conditions for how such a situation can be achieved and show that it can do so with semicentralization, low complexity and limited crosstalk channel information-only the ratios between crosstalk channels are necessary. Performance is very close to optimal.
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| 7. |
- Zampolo, Ronaldo de Freitas, et al.
(författare)
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Mapping The Impulse Noise Spectral Features From Waveform Domain Onto Symbol Domain
- 2006
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Ingår i: 6th International Telecommunications Symposium. - 9788589748049 ; , s. 193-197
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Konferensbidrag (refereegranskat)abstract
- In this paper the spectral features of impulse noise in DSL systems are mapped from the waveform domain onto the symbol domain, considering a QAM receiver. This work can be viewed as part of a full symbol domain model for impulse noise, which should include the amplitude and spectral aspects. Since the available models of impulse noise in DSL are generally waveform-based, this kind of mapping is justified when symbol-based simulations are intended, in order to avoid computational overhead due to demodulating noise samples generated on waveform domain. The analytical development of such mapping is provided as well as some simulation results.
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