| Patent application number | Description | Published |
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| 20080219413 | SYSTEMS AND METHODS FOR LOOP GAUGE DETECTION BASED ON PER-PORT CALIBRATION - Systems and methods for performing loop gauge detection are described. One embodiment is a method that comprises receiving a calibrated per-port echo signal of a loop under test, receiving a loop length estimation for the loop under test, and estimating the loop gauge of the loop under test if the loop is not determined to be a long loop based on a predetermined threshold and if no bridge tap is present on the loop. In accordance with such embodiments, estimating the loop gauge of the loop under test is based on at least one of the following echo signal features: energy of the echo signal in a predetermined frequency band, information on an envelope of maxima for the echo signal, information on an envelope of minima for the echo signal, and a span of ripples on the amplitude of the echo signal. | 09-11-2008 |
| 20080240368 | SYSTEMS AND METHODS FOR BRIDGE TAP DETECTION BASED ON PER-PORT CALIBRATION - Systems and methods for performing bridge tap detection are described. One embodiment is a method which comprises receiving an echo signal for a loop under test where the echo signal is a per-port calibrated echo response obtained using frequency domain reflectometry single-ended line testing (FDR-SELT). The method further comprises analyzing the echo signal to determine whether differentiating features are present in the per-port calibrated echo signal in order to determine whether the loop under test is a bridge tapped loop. | 10-02-2008 |
| 20080263413 | Back Channel Communication - Included are embodiments for back channel communication. At least one embodiment of a method includes receiving data at customer premises equipment and determining at least one error in the received data. Some embodiments include formatting the determined error for communication to a central office and sending the formatted error to the central office via a back channel. | 10-23-2008 |
| 20080267392 | Crosstalk Recognition in Presence of Radio Frequency Interference - Crosstalk interference induced by the adjacent pairs is one of the major performance limiting factors of DSL systems. As there is a rapid increase in the deployment of DSL services worldwide, the need to provide information about noise related parameters to the operators and the service providers is of utmost importance. Satisfying such a need enables operators to anticipate the line capacity and understand the noise level characteristics of the loop environment. Specifically, crosstalk and more particularly upstream near end crosstalk (NEXT) in the presence of narrowband interference can be classified to isolate the particular service type causing the upstream NEXT. The identification of the service type of the upstream NEXT would enable operators to address the disturber. | 10-30-2008 |
| 20080273638 | Reducing the Effect of Noise in a Multi-Channel Telecommunication Receiver - A telecommunication receiver provided according to the present invention is implemented to receive a first signal containing information and noise on a first set of sensors and a second signal containing only noise on a second set of sensors. Receiver then decodes the information using first signal and second signal. In one embodiment, a bonded DSL receiver with k signals sensors is implemented with additional s number of noise only sensors to receive only noise. Accordingly, joint demodulation is performed using signals received on k signals sensors and s noise only sensors. The noise sensor is implemented in common mode. | 11-06-2008 |
| 20080279269 | SYSTEMS AND METHODS FOR LOOP TERMINATION DETECTION BASED ON PER-PORT CALIBRATION - Systems and methods for performing loop termination are described. One embodiment is a method that comprises receiving a per-port calibrated echo signal of a loop under test, receiving a region designation and a loop length for the loop under test, and determining whether the loop is terminated by a short or open termination based on phase of the per-port calibrated echo signal. | 11-13-2008 |
| 20080298555 | SYSTEMS AND METHODS FOR LOOP LENGTH ESTIMATION BASED ON PER-PORT CALIBRATION - Systems and methods for performing loop length estimation are described. One embodiment includes a method which comprises receiving an echo signal for a loop under test where the echo signal is a per-port calibrated echo response obtained using frequency domain reflectometry single-ended line testing (FDR-SELT). The method further comprises analyzing characteristics of the echo signal to perform a loop length estimation based on data relating to ripple frequency as a function of loop length. | 12-04-2008 |
| 20080310296 | Systems and Methods for Transmit-Only Peak-to-Average Ratio Reduction in the Oversampled Regime Using Reserved Tones - Systems and methods for reducing the peak-to-average power ratio (PAR) at the transmitter can reduce the dynamic range required in various analog components. PAR can be reduced by applying a time-domain compensation signal in the oversampled regime, using tones reserved for PAR reduction. A set of vectors corresponding to PAR tones is generated by processing out-of-phase symbols for each PAR tone to form a span matrix. The span matrix is used to find a best fit of a desired target signal to a time-domain compensation signal comprising only PAR tones. | 12-18-2008 |
| 20090122855 | Systems and Methods for Mitigating the Effects of Upstream Far-End Cross Talk - Systems and methods for mitigating the effects of self-FEXT within an xDSL system are described. At least one embodiment is a method for reducing self-induced far end crosstalk (self-FEXT) in a multiple input multiple output (MIMO) digital subscriber line (xDSL) system. The method comprises deriving an initial value for an off-diagonal multiple input multiple output canceller (ODMC) while the ODMC is inactive and while in data mode. The method further comprises activating the initial ODMC and converging towards an steady-state value for the ODMC by performing an adaptive algorithm to maximize the Shannon's capacity of the system and to reduce upstream self-FEXT. The method also comprises performing bit loading and updating a frequency domain equalizer (FEQ). | 05-14-2009 |
| 20090177938 | Cognitive and Universal Impulse Noise Protection - Impulse noise from nearby or intense electrical sources can disrupt communications over digital subscriber lines. There are many methods to deal with errors produced by impulse noise sources. Forward error correction (FEC) codes such as Reed Solomon coding along with scrambling and interleaving are used to correct small errors. However, for larger errors, retransmission is favored. Retransmission can be applied at the Discrete Multi-tone symbol level thus eliminating the need to insert sequence identification into data transmission units, furthermore retransmission can also be employed to exploit the error correcting capabilities of the FEC codes. Finally, an impulse noise protection system can exploit impulse noise statistics to configure the redundancy in the FEC codes and to enable the use of blanking. Exemplary embodiments of systems described can cooperatively use impulse noise statistics to utilize retransmission, FEC and blanking to mitigate the effects of impulse noise. | 07-09-2009 |
| 20090216489 | SYSTEMS AND METHODS FOR DERIVING PARAMETERS FOR IMPULSE NOISE DETECTORS - Systems and methods for deriving parameters for frequency domain impulse noise detectors are described. At least one embodiment is a method for deriving a set of parameters associated with a frequency domain impulse noise detector. In accordance with such embodiments, the method comprises setting values for β | 08-27-2009 |
| 20090219979 | System and Method for Selectable Mask for LDSL - The present invention overcomes various problems by defining two upstream masks (U | 09-03-2009 |
| 20090232232 | Metric Computation for Lowering Complexity of MIMO Detection Algorithms - Included are embodiments of method for method for computing metrics. At least one embodiment includes searching a MIMO detection tree, the detection tree configuration being formed by a plurality of nodes and a plurality of leaves connected via a plurality of branches, the computational complexity associated with computing a node metric decreases with the node depth in the tree configuration and providing an estimate on a transmitted signal. | 09-17-2009 |
| 20090252234 | SYSTEMS AND METHODS FOR MONITORING IMPULSE NOISE - Systems and methods for monitoring impulse noise are described. At least one embodiment is a method, which comprises detecting whether impulse noise is present and in response to detecting the presence of impulse noise, performing time domain analysis to determine whether one or more impulse noise sources are present based on minimum interarrival time and maximum impulse length. The method further includes performing frequency domain analysis to estimate frequencies associated with the one or more impulse noise sources and based on the time domain analysis and frequency domain analysis, providing a total number of impulse noise sources and frequencies associated with the impulse noise sources. In this regard, the embodiments described herein provide dual-speed monitoring of impulse noise in the form of short-term and long-term monitoring. The use of dual-speed monitoring ensures that dynamic changes in the impulse noise environment are quickly addressed and also ensures better characterization of multiple impulse noise sources in order to provide better impulse noise protection. | 10-08-2009 |
| 20090257581 | Cooperative MIMO for Alien Noise Cancellation (COMAC) for Upstream VDSL Systems - Included are embodiments for reducing alien crosstalk. At least one embodiment of a method includes receiving noise data associated with a first user signal on a first tone, receiving noise data associated with a second user signal on the first tone, and receiving at least one alien crosstalk canceller coefficient for the first user on the first tone. Some embodiments include applying the at least one alien crosstalk canceller coefficient to the second user signal to reduce alien crosstalk for the first user signal. | 10-15-2009 |
| 20090310658 | Systems and Methods for Positioning and Messaging of Reserved Tones for Peak-to-Average Ratio (PAR) Reduction in DSL Systems - Systems and methods for reducing the peak-to-average ratio (PAR) at the transmitter can reduce the dynamic range required in various analog components. PAR can be reduced by applying a time-domain compensation signal which reduces the magnitude of peaks in the time-domain signal prior to transmission where the time-domain compensation signals use tones that are reserved for the purpose of reducing the PAR. The reservation of these reserved tones for PAR can be implemented by altering the typical startup procedures in a digital subscriber line (xDSL) system. The use of the reserved tones to reduce the PAR can be implemented using a low complexity algorithm or using an adaptive technique. | 12-17-2009 |
| 20090310659 | Adaptive Turbo Peak Mitigation for Peak-to-Average Ratio (PAR) Reduction Using Reserved Tones - Systems and methods for reducing the peak-to-average ratio (PAR) at the transmitter can reduce the dynamic range required in various analog components. PAR can be reduced by applying a time-domain compensation signal which reduces the magnitude of peaks in the time-domain signal prior to transmission where the time-domain compensation signals use tones that are reserved for the purpose of reducing the PAR. The reservation of these reserved tones for PAR can be implemented by altering the typical startup procedures in a digital subscriber line (xDSL) system. The use of the reserved tones to reduce the PAR can be implemented using a low complexity algorithm or using an adaptive technique. | 12-17-2009 |
| 20090310704 | Low Complexity Systems and Methods for Peak-to-Average Ratio (PAR) Reduction Using Reserved Tones - Systems and methods for reducing the peak-to-average ratio (PAR) at the transmitter can reduce the dynamic range required in various analog components. PAR can be reduced by applying a time-domain compensation signal which reduces the magnitude of peaks in the time-domain signal prior to transmission where the time-domain compensation signals use tones that are reserved for the purpose of reducing the PAR. The reservation of these reserved tones for PAR can be implemented by altering the typical startup procedures in a digital subscriber line (xDSL) system. The use of the reserved tones to reduce the PAR can be implemented using a low complexity algorithm or using an adaptive technique. | 12-17-2009 |
| 20090310755 | SYSTEMS AND METHODS FOR PERFORMING LOOP ANALYSIS BASED ON UN-CALIBRATED SINGLE-ENDED LINE TESTING - Systems and methods for performing loop analysis are described. Some embodiments are directed to determining loop characteristics such as loop gauge, loop termination, and straight-loop departure. One embodiment includes a method for performing loop length estimation which comprises receiving an un-calibrated echo signal for a loop under test using frequency domain reflectometry single-ended line testing (FDR-SELT), a region associated with the loop under test, and a platform type. The method comprises classifying the loop under test and outputting a loop length estimate based on the classification of the loop under test and based on one of a ripple-period approach and a template-matching approach. | 12-17-2009 |
| 20090323902 | SYSTEMS AND METHODS FOR CHARACTERIZING LOOPS BASED ON SINGLE-ENDED LINE TESTING (SELT) - Systems and methods for characterizing loops based on single-ended line test (SELT) are described. One embodiment includes a method for determining whether a straight-loop departure condition exists on a loop under test. In accordance with such embodiments, the method comprises receiving an un-calibrated echo signal for the loop under test using frequency domain reflectometry single-ended line testing (FDR-SELT), a region associated with the loop under test, a platform type, and a length of the loop under test. Based on the region, platform type, and loop length, the method further comprises determining whether the loop is not a straight loop, wherein determining whether the loop is not a straight loop comprises determining whether at least one differentiating feature is present in the un-calibrated echo signal. Another embodiment includes a method for determining a loop gauge for a loop under test. The method comprises receiving an un-calibrated echo signal for the loop under test using frequency domain reflectometry single-ended line testing (FDR-SELT), a region associated with the loop under test, a platform type, and a length of the loop under test. Based on the region, platform type, and loop length, the method further comprises analyzing characteristics relating to local maxima and local minima of the un-calibrated echo signal to determine the loop gauge. | 12-31-2009 |
| 20100002808 | SYSTEMS AND METHODS FOR PERFORMING SISO DETECTION IN A WiMAX ENVIRONMENT - In accordance with some embodiments, a communication system is described that comprises a soft-output detector configured to receive a transmit signal and output reliability information regarding the received signal. In accordance with such embodiments, the detector comprises a symbol combiner configured to operate in both a repetition mode and a non-repetition mode, wherein repetition mode comprises receiving a plurality of signals for the transmit signal. | 01-07-2010 |
| 20100017678 | Hierarchical Trellis Coded Modulation - A system and method for encoding information is disclosed. In one embodiment, information is encoded using a high protection code for the least significant bit and a low protection code for the next three most significant bits. The remaining bits are uncoded. The high protection code may be a turbo code and the low protection code may be a trellis coded modulation code. In this embodiment, the collection of bits is then mapped according to a diagonally shifted QAM constellation technique. | 01-21-2010 |
| 20100061434 | DSL Loop Topology Recognition Based on the Insertion Loss (Hlog) Measurements - The topology of a digital subscriber line loop can play an important role in provisioning service. For example, knowledge of certain topological features in a loop can enable telecommunications companies to make better decisions about the kinds of services that can be provisioned on that loop. Additionally, knowledge of those topological features can also assist field engineers in troubleshooting problems in the field. A topology recognition engine can provide key topological features such as the loop length, presence of single and multiple bridge taps and the length of single bridge taps on a loop. | 03-11-2010 |
| 20100061437 | Systems and Methods for Impulse Noise Characterization - Impulse noise from nearby or intense electrical sources can disrupt communications over digital subscriber lines (DSL). The characterization of the nature, timing and length of impulse noise sources present on a DSL loop is a critical first step in mitigating the effect of impulse noise on DSL communications. DSL standards provide histograms for impulse length and inter-arrival time of impulses. These histograms can be used to derive the nature, maximum frequency and other statistics related to impulse noise on a DSL line. | 03-11-2010 |
| 20100086105 | SYSTEMS AND METHODS FOR CHARACTERIZING LOOP TERMINATION VIA SINGLE-ENDED LINE TESTING - Disclosed are various embodiments for determining a state of loop termination. One embodiment comprises receiving an un-calibrated echo signal for the loop under test using frequency domain reflectometry single-ended line testing (FDR-SELT) and determining the state of loop termination based on phase of the un-calibrated echo signal. The step of determining the state of loop termination comprises determining whether the loop is terminated by an open termination or a short termination by correlating the phase of the echo signal with an expected phase of the echo signal derived from measurements taken at the same loop length for open and short terminations. For other embodiments, the amplitude of the un-calibrated echo signal is analyzed to determine whether the loop is terminated by a matched-impedance termination. | 04-08-2010 |
| 20100177815 | SYSTEMS AND METHODS FOR PERFORMING COMBINED EQUALIZATION IN COMMUNICATION SYSTEMS - A system is described for performing combined equalization. The system comprises a time domain equalizer (TEQ) configured to receive a signal and shorten a CIR (channel impulse response) of the received signal, a Fast Fourier Transform (FFT) module for demodulating the received signal, and an equalization block for reducing inter-carrier interference (ICI) and inter-symbol interference (ISI). The equalization block comprises at least one of: a feed forward equalizer and a feed back equalizer. The system further comprises a slicer circuit configured to generate a hard-limited decision for a symbol corresponding to the received signal. | 07-15-2010 |
| 20110167325 | Back Channel Communication - Various embodiments are described for back channel communication. One embodiment is a method that comprises receiving data at customer premises equipment (CPE), determining at least one error in the received data, formatting the determined error for communication to a central office (CO), and sending the formatted error to the CO via a back channel, wherein the formatted error is sent between sync frames of a discrete multitone (DMT) superframe. | 07-07-2011 |
