Abstract: A method, apparatus, and system for detecting a tone. In some embodiments, a signal is communicated by applying a first quantity of samples per period and a second quantity of samples per period. The samples may then be translated into information. For example, the first and second quantity of samples may be translated into information and identified. According to some embodiments, a signal communicates information at at least two different frequencies simultaneously to determine a common carrier for transmitting and receiving nodes.

Abstract: In one embodiment, a method is provided. The method of this embodiment provides receiving a communication having a data sample set, generating a selective data sample set based, at least in part, on the data sample set, and using the selective data sample set to update a training algorithm using an updating algorithm.

Abstract: Embodiments of the invention provide methods for determining the characteristics of a local loop using the multi-carrier tones of a DSL activation process. For one embodiment, one or more sets of downstream multi-carrier tones of a digital subscriber line activation process are received at an extended voice-band modem and are capable of transmitting upstream multi-carrier tones of the digital subscriber line activation process over a local loop. The downstream carrier tones and the upstream carrier tones are folded into a first multi-tone signal and a second multi-tone signal, respectively, each having a plurality of component signals within the spectrum band of the extended voice-based modem. The total signal power of the first multi-tone signal is divided by the power of one of the plurality of component signals of the second multi-tone signal to determine a ratio value. The ratio value is used to determine a characteristic of the local loop.

Abstract: In some embodiments, a method includes performing at least part of a digital subscriber line (DSL) handshaking process by transmitting at least one handshaking signal via a telephone subscriber loop, and analyzing the at least one handshaking signal to detect a characteristic of the telephone subscriber loop.

Abstract: Embodiments of the invention provide methods and apparatuses to determine the characteristics of a local loop using the multi-tone line-probing signals of a standard voice-based modem. For one embodiment, the multi-tone, line-probing signals of a voice-band modem are transmitted over a local loop and received at a standard voice band modem. Discrete fourier transform values are determined for each of two or more frequencies of the plurality of frequencies of the multi-tone signals. A set of discrete fourier transform values corresponding to a set of high frequencies is summed to obtain a first value and a set of discrete fourier transform values corresponding to a set of low frequencies is summed to obtain a second value. A power ratio is determined by dividing the first value by the second value. The power ratio is then used to determine a characteristic of the local loop.

Abstract: A technique is proposed to accurately estimate the Network CODEC levels for each PCM code a server modem generates. These levels are affected by the digital impairments such as Digital attenuation PAD in the trunk, the Robbed Bit Signaling, the type of CODEC (&mgr;-law or a-law—or non standard), and by analog impairments such as loop distortion, noise, inter-modulation distortion, echo. At client modem equalizer output good estimates for these levels are derived. By detecting RBS pattern of the trunk, and using averages of decode levels of similar RBS slots, more accurate data points are obtained. By further replacing these levels with the closest CODEC receive levels, good accuracy is obtained. Non-monotonic points are detected and eliminated. An upper limit is set for constellation points to avoid saturation of the receiver. IMD correction is applied to the decode levels. Ideal points that are not signaled, are added if possible.

Abstract: A method, apparatus, and system for detecting a tone.

Abstract: A method, apparatus, and system for adaptively synchronizing a sampling clock.

Abstract: A technique is proposed to accurately estimate the Network CODEC levels for each PCM code a server modem generates. These levels are affected by the digital impairments such as Digital attenuation PAD in the trunk, the Robbed Bit Signaling, the type of CODEC (&mgr;-law or a-law—or non standard), and by analog impairments such as loop distortion, noise, inter-modulation distortion, echo. At client modem equalizer output good estimates for these levels are derived. By detecting RBS pattern of the trunk, and using averages of decode levels of similar RBS slots, more accurate data points are obtained. By further replacing these levels with the closest CODEC receive levels, good accuracy is obtained. Non-monotonic points are detected and eliminated. An upper limit is set for constellation points to avoid saturation of the receiver. IMD correction is applied to the decode levels Ideal points that are not signaled, are added if possible .

Abstract: A method of generating a data constellation at a client modem is provided whereby an optimum distance between data constellation data points may be calculated for a predetermined, acceptable error probability. An iterative process may be carried out using proposed data constellations which may be used to provide factors for calculating corrected constellations. Once a constellation is generated to satisfy the required probability of error, the constellation may be re-evaluated using CRC errors and detected noise variance at the client modem. Based upon predetermined levels of noise variance and CRC error, the constellation may be regenerated to operate at either a higher bit rate or a lower bit rate.

Abstract: A table-lookup device includes an input to receive a plurality of data bits. A first combiner is included to combine a generator polynomial and a known polynomial and to provide an auxiliary generator polynomial. A data table array is based on the auxiliary generator polynomial. A memory is included to store the data table array. A second combiner is included to combine the plurality of data bits and the auxiliary generator polynomial and to provide a table array index. The table array index indicates an address of an element of the data table array.