Paradyne Corporation

Summit Technology Systems, LP

Rembrandt Communications, LP

Summit Technologies Systems, LP

Rafael S Martinez

William Lewis Betts

Gordon F Bremer

Thomas Jeffrey Bingel

Chuck Coston

Ed Thoenes

Kenneth David Ko

Keith R Nauman

Various embodiments are configured to transform characteristics of a communication signal. One embodiment is a method comprising decreasing amplitude of a first detected portion of the communication signal so that the decreased amplitude is in close proximity to a predefined specification; and increasing amplitude of a second portion of the communication signal so that the increased amplitude is in close proximity to the predefined specification, thereby resulting in a transformed communication signal.

Subscriber line driver with equalizer

The present invention provides methods and apparatus for transmitting a data-bearing signal and a non-data-bearing signal. One embodiment comprises communicatively coupling a data-bearing signal during a first time period and communicatively coupling a non-data-bearing signal during a second time period. The data-bearing signal has a first PSD. The non-data-bearing signal has a second PSD substantially the same as the first over a range of frequencies. The non-data-bearing signal has characteristics facilitating echo cancellation. Another embodiment comprises a line interface and a transmitter coupled to the line interface, comprising a data encoder and a periodic signal generator. The encoder is configured to produce a data-bearing signal with a first PSD. The periodic signal generator is configured to produce a non-data-bearing signal with a second PSD. The second PSD is substantially the same as the first PSD over a first range of frequencies. The non-data-bearing signal has characteristics facilitating echo cancellation.

System and method for subliminal time domain duplexing

The present invention provides for a system and method for reducing power consumption in frame and cell data transmission systems. A transmitter power manager powers down (turns off) selected elements of a transmitter system during periods of transmitter inactivity. The transmitter power manager system detects incoming communication signals which are to be transmitted by the transmitter, and at the appropriate time, powers up (turns on) the selected elements which are controlled by the transmitter power manager.

System and method for minimized power consumption for frame and cell data transmission systems

A system and method for providing a minimum burst duration in accordance with a regional standard and/or requirement. One embodiment comprises a first interface () configured to receive data to be communicated, a memory () configured to store a value corresponding to a regional minimum duration, a processor () configured to generate a frame, configured to compare a duration of the generated frame with the regional minimum duration, configured to add at least one padding symbol to the generated frame to generate a second frame, the second frame having a duration at least equal to the regional minimum duration, and a second interface () configured to communicate the second frame onto a communication channel.

Communication system and method for minimum burst duration

A symbol timing derivation system derives receiver timing from received symbols which avoids the need for a pilot tone, thereby reducing power consumption and expanding usable bandwidth. The system is implemented by using a calculation that finds the timing phase error. The timing phase error is then averaged and controls a phase locked loop (PLL). This PLL in turn controls a voltage-controlled oscillator, which handles the modem receiver timing. A centroid calculation can be included to bias the voltage-controlled oscillator to push the equalizer coefficients back to the ideal position. The system can be implemented in either a point-to-point modem environment or a multi-point environment, for example, but not limited to, MVL or DMT. The voltage-controlled oscillator may also be implemented to control transmitter timing, so that the central office modem and the remote modem will operate more-or-less synchronously, reducing the need for large equalizer corrections at either end.

System and method for deriving symbol timing

A transient pre-emptor includes a processor configured to detect transients in a communications system. After the processor detects a transient in the communications system, it causes a data communications equipment to suspend or reduce data transmission during the occurrence of a subsequent transient.

Method and apparatus for reducing transmission errors caused by periodic transients in digital subscriber line (DSL) communication systems

A subscriber line driver (SLD) is provided for the continuous and automatic transformation of the characteristics of a communication system signal so that the signal conforms to a power spectral distribution (PSD) standard. The signal is transformed by the SLD which may increase (amplify) portions of the signal to a predefined specification, decrease (attenuate) portions of the signal to a predefined specification, and/or frequency modulate or filter the transmit signal frequencies to fit within the communication channel frequency bandwidth as defined by a predefined frequency band. After modification by the SLD, the transformed communication signal is injected (transmitted) into a communication transmission line. An SLD device can be employed in a variety of communication systems such as a public telephony system, a private branch exchange (PBX), a coaxial cable system, a fiber optic system, a microwave system, a radio communication system or the like. In the preferred embodiment, the SLD device operates in connection with a telephony system local loop which is operated as a digital subscriber loop (DSL). The SLD has an infinite input impedance at all frequencies. Addition of a parallel resister can enable the design engineer to set the transmission system terminating impedance to any desired value. This SLD can also be implemented in connection with a telephony system central office (CO) or a PBX.

Subscriber line driver and termination

The eavesdropping prevention system and method of the present invention provides a mask signal generator which generates a mask signal superimposed over a leakage signal. The mask signal prevents meaningful detection and amplification of the leakage signal. The amplitude of the mask signal is low enough so as not to interfere with the transmission of analog POTS signals over the communication line on which the mask signal is superimposed. In the preferred embodiment, the amplitude of the mask signal exceeds the amplitude of any anticipated leakage signals which may be manifested on the communication line. Alternative embodiments of a mask signal are described.

Line sharing multipoint POTS splitter masking noise

The present invention provides a method and apparatus for reducing the number of bit errors that occur in xDSL data transmissions as a result of baseband ringing. It has been determined that the number of bit errors that occur in xDSL data transmissions as a result of baseband ringing can be reduced by lowering the data transmission rate to a predetermined rate while baseband ringing is occurring. The apparatus of the present invention detects when baseband ringing is occurring over a communication system and causes the data communication equipment (DCE) device located at the central office and the DCE located at the customer premises to begin communicating at a lower, predetermined transmission data rate. When a determination is made by the apparatus that the baseband ringing is no longer present, the apparatus causes the DCE located at the central office and the DCE located at the customer premises to begin communicating at the original data transmission rate. This temporary rate reduction results in an increased operating margin during, and slightly beyond, the time interval in which baseband ringing is occurring.

Method and apparatus for reducing transmission errors in digital subscriber line (DSL) communication systems

An improvement to a half duplex multipoint communication environment wherein a pilot tone enables a control device to maintain synchronization with a plurality of remote devices. The present invention employs a quantization noise compensator apparatus and method to supply a single bit, two level analog signal to drive a Voltage Controlled Crystal Oscillator (VCXO) in a remote device. The VCXO derives the sample rate signal for both transmit and receive devices, eliminating the requirement for a highly accurate digital to analog converter, thus reducing the cost and complexity of the system while allowing continuous synchronization between a control device and a plurality of remote devices.

Quantization noise compensator apparatus and method

An improvement to a half duplex multipoint communication environment wherein a digital subscriber line (DSL) receiver employs an adaptive comb filter and a decision feedback equalizer (DFE) to efficiently suppress or eliminate low frequency periodic impulse noise and crosstalk generated in the vicinity of the device receiver.

Growing community of inventors

Clearwater, FL, United States of America

Rafael S Martinez