High-bit-rate digital subscriber line

About: High-bit-rate digital subscriber line is a research topic. Over the lifetime, 516 publications have been published within this topic receiving 8537 citations. The topic is also known as: HDSL & high-bit-rate DSL.

Method of measuring and improving xDSL transmission characteristic

Abstract: In accordance with the present invention, a system for measuring the transmission characteristic of an xDSL system that implements high-speed data communication over existing copper wires connecting an office and a subscriber includes a pulling device included in the outside line of an xDSL circuit, which is installed in an office, for pulling a subscriber line. A noise level measuring circuit measures the level of cross-talk noise on the subscriber line. A decision circuit determines, based on the level of cross-talk noise measured, whether or not the subscriber line is usable.

Design issues for early high bit-rate digital subscriber lines

Abstract: The design and performance of high-bit-rate digital subscriber loop (HDSL) transceivers is examined with the intention of devising systems with signal processing and technology requirements that are not vastly dissimilar to those of basic access transceivers. The topology, line codes, postcursor equalization, precursor equalization, and noise prediction of a simple HDSL transceiver are discussed. A design strategy that would allow early development of an HDSL transceiver to provide 800-kb/s access is explored. A useful benchmark against which the performance versus complexity tradeoff of more sophisticated systems may be assessed is described. >

Performance of a 51.84-Mb/s VDSL transceiver over the loop with bridged taps

Abstract: This paper presents a study of the effects of bridged taps on very high-speed digital subscriber line (VDSL) transmission systems. It is shown that the short bridged taps, which affect VDSL signals, are much more damaging than the longer bridged taps, which affect other xDSL signals, such as high-rate digital subscriber line (HDSL) and asymmetric digital subscriber line (ADSL). Specifically, short bridged taps introduce a lot of linear distortion in the loop's transfer function. In addition, they also tend to introduce more overall propagation loss than longer bridged taps. The peak-power-to-average-power ratio (PAR) of the signal increases for the loop with short bridged taps, and thus more A/D bits are needed in the implementation of a digital VDSL transceiver as compared to the loop with long bridged taps. The performance of various equalizer structures is discussed in the presence of a severe channel distortion caused by the bridged tap.

Minimizing crosstalk in twisted pair wires carrying TDD multitone signals

Abstract: A digital transmission system comprises a plurality of wire sets 151, 155, such as twisted-pair wires, for delivering services to subscribers 110, 120, 130, 140. A first wire set 151 carries a time-division duplexed multitone signal VDSL. The system is arranged to individually select the transmitted spectra of the upstream and downstream portions of the duplexed signal so as to minimise cross-talk interference with further signals ADSL, HDSL carried by other wire sets 155. In use the transmitted spectra of the upstream and downstream portions of the duplexed signal may differ in bandwidth.

Method, Apparatus, and System for Reducing Digital Subscriber Line Interference

Abstract: The present invention provides a method, an apparatus, and a system for reducing digital subscriber line interference. The method includes identifying at least one legacy digital subscriber line in a digital subscriber line DSL legacy line set, obtaining a target power spectral density mask value of the legacy digital subscriber line, and reducing power spectral density of a transmit signal on the legacy digital subscriber line according to the target power spectral density mask value.