Abstract: The present invention relates to methods and systems for minimizing alien crosstalk between connectors. Specifically, the methods and systems relate to isolation and compensation techniques for minimizing alien crosstalk between connectors for use with high-speed data cabling. A frame can be configured to receive a number of connectors. Shield structures may be positioned to isolate at least a subset of the connectors from one another. The connectors can be positioned to move at least a subset of the connectors away from alignment with a common plane. A signal compensator may be configured to adjust a data signal to compensate for alien crosstalk. The connectors are configured to efficiently and accurately propagate high-speed data signals by, among other functions, minimizing alien crosstalk.

Abstract: An access node of a communication system comprises a plurality of transmitters adapted for communication with at least one receiver. The access node is operative to simultaneously estimate channel coefficients between multiple ones of the transmitters and the receiver, and to utilize the estimated channel coefficients to control at least one data signal sent by at least one of the multiple transmitters to the receiver. In the process of simultaneously estimating the channel coefficients, the access node transmits a plurality of distinct probing signals generated based on respective ones of a plurality of different frequency expansions. For example, each of the distinct probing signals may be generated based on a distinct combination of a common probing sequence and a selected one of the plurality of different frequency expansions.

Abstract: A line state detecting apparatus provided in a balanced transmission system includes, in transmission lines comprising a pair of conductors W1, W2 connected to a transmitting portion 13, current transformers T11, T12 primary sides of which are inserted to respectives thereof in series therewith and secondary sides of which are connected in series to cancel currents or voltages of the two transformer by each other, and a detecting portion 11 for detecting currents or voltages on secondary sides of the current transformers T11, T12. By an output of the detecting portion 11, a difference of currents or voltages of the conductors W1, W2 of the transmission lines is provided and an unbalance component between the conductors W1, W2 is detected.

Abstract: Methods, techniques and apparatus identify members and characteristics of binders and/or other groups of communication lines such as those in a DSL system. Information obtained includes the identification (for example, by scanning) of significant crosstalking “offenders” and their “victims” that are affected by the crosstalk. One or a small number of modems are instructed to transmit with preselected transmit spectra, after which evidence of crosstalk in the noise spectrum data is examined for potential victim lines. Direct evidence of noise spectrum contribution by a suspected offender line may be obtained by collecting reported noise spectrum data and/or estimated noise spectrum data from potential victim lines. Also, where such direct evidence is not available, or in addition to it, other operational data showing crosstalk interference relating to potential victim lines can be used. The transmitting modem can either be on the CO/RT side or on the CPE side.

Abstract: The present invention relates to methods and systems for minimizing alien crosstalk between connectors. Specifically, the methods and systems relate to isolation and compensation techniques for minimizing alien crosstalk between connectors for use with high-speed data cabling. A frame can be configured to receive a number of connectors. Shield structures may be positioned to isolate at least a subset of the connectors from one another. The connectors can be positioned to move at least a subset of the connectors away from alignment with a common plane. A signal compensator may be configured to adjust a data signal to compensate for alien crosstalk. The connectors are configured to efficiently and accurately propagate high-speed data signals by, among other functions, minimizing alien crosstalk.

Abstract: A device has a plurality of output terminals to provide a plurality of signals to a plurality of transmission links; at least one input terminal to receive information representing a projection of a complex valued error signal onto one direction; and a determination circuit, coupled to the at least one input terminal.

Abstract: A noise cancellation system configured to isolate and process a common mode noise signal to generate a cancellation signal. The cancellation signal is combined with a differential signal to cancel unwanted differential mode noise that coupled onto the differential signal. In one embodiment a multi-channel communication system utilizes two or more channels that are in close proximity to other alien channels. A common mode signal isolation unit is configured to isolate common mode noise. The common mode noise signal is processed with a filter or other means to generate a cancellation signal. The cancellation signal is combined with the differential signal to thereby cancel noise that coupled onto the differential signal. The processed common mode noise signal may be made to approximate the differential mode noise signal. The common mode signal may be obtained from a center tap of a transformer, or a sensing winding of a three winding transformer.

Abstract: A high bandwidth telephone line transceiver for connecting telecommunications equipment to a telephone line provides a pair of isolation capacitors connected to the telephone line to transmit the telephone signals across the requisite electrical isolation barrier. The capacitors are connected to a user-side hybrid circuit that provides a line impedance match for the telephone circuit, and converts the two wire connection to the capacitors to a 4 wire circuit for separate transmit and receive signal paths. The receive signal path extends through a signal op amp to a high pass filter that transmits the DSL download bandwidth and rejects the upload bandwidth and voice spectrum. The received signal is then fed to an analog/digital converter, and the digitized signal is connected to a DSP. The DSP is connected to a data handling device via a USB port, a PCI interface, or the like. The transmit signal path extends from the DSP circuit to a transmit path digital/analog converter.

Abstract: A load coil device for a twisted pair telephone line is disclosed. The device is for compensating distributed stray capacitance in telephone lines that are longer the 18,000 feet. Typically, a load coil device would be inserted in the line every 6,000 feet. The device includes two windings, each winding to be connected in series with one of the conductors of the telephone line. The windings flatten the frequency response of the line in the voice frequency (VF) band. The device further has a capacitor connected in parallel across each winding. The values of the capacitors are chosen to provide a low impedance path that bypasses the windings for frequencies in the range of 20 kHz to 1.1 MHz. The device is particularly useful for long telephone lines over which high speed services such as asynchronous digital subscriber line (ADSL) are to be provided.

Abstract: The present invention is directed to an adaptor for measuring an echo return loss in a communication system. The adaptor includes two transformers, each having a primary winding and two secondary windings. The secondary windings are cross-connected to form first and second out of phase circuits. The first circuit includes impedance elements which match an impedance of an external device. When the external device is attached to the second circuit, the first and second circuits are schematically equivalent, albeit out of phase. When an oscillation signal is input to one transformer, the matched impedance and out-of-phase connection of the secondary windings cancel the signal such that only an echo signal is output by the other transformer.

Abstract: A constant voltage drive type driver circuit includes a pulse transformer for outputting output pulses having a predetermined peak value and having primary and primary windings. The secondary winding has first and second terminals and an equivalent load impedance is connected to the secondary winding when viewed from the pulse transformer excluding an impedance of the secondary winding itself. A power source supplies a voltage, and a switching circuit supplies the voltage from the power source to the primary winding of the pulse transformer in a first mode and cuts off the supply of the voltage to the primary winding in a second mode in response to control signals. A short-circuiting part short-circuits the first and second terminals of the primary winding of the pulse transformer for a predetermined time from a time when the switching circuit assumes the second mode.

Abstract: A method and apparatus for providing a telephone line interface having selectable termination characteristics, such as impedance parameters, is provided using AC and DC transconductance loops. The present invention may be used with modem apparatus to provide regulatory compliance of line termination characteristics in multiple countries having different, even conflicting, standards or regulations. The preferred embodiment of the present invention uses a programmable switched capacitor filter to drive a transconductance driver that drives the telephone line. An AC transconductance loop controls AC transconductance characteristics, while a DC transconductance loop controls DC transconductance characteristics.

Abstract: A noise suppression inductor including a bobbin having a spool divided into a plurality of spool portions, a core mounted on the bobbin, at least one coil wound around the spool portions into a plurality of coil portions and a plurality of terminal pins connected to opposite ends of the coil, in which the coil portions have different winding widths such that stray capacities produced at the coil portions are made different from each other, whereby the noise suppression inductor has a plurality of self-resonance frequencies.

Abstract: A noise suppression inductor including a bobbin having a spool divided into a plurality of spool portions, a core mounted on the bobbin, at least one coil wound around the spool portions into a plurality of coil portions and a plurality of terminal pins connected to opposite ends of the coil, in which at least one of the coil portions is composed of a first part having one or two winding layers and a second part having one winding layer and at least another one of the coil portions has not less than two winding layers.