Abstract: Embodiments provide solutions to reduce power utilization (either at individual cable modems or in the overall network) in future cable modem networks. Particularly, embodiments seek to reduce power utilization at individual cable modems and in the overall network, by allocating upstream frequency bands and/or transmission modulation schemes among cable modems while accounting for cable loss experienced by individual upstream cable modem transmissions. According to embodiments, frequency spectrum and modulation scheme allocation techniques are provided to optimize power utilization and enable lower upstream transmission power by cable modems while maintaining similar signal strength of received signals or lower signal strength with reduced SNR requirements using lower capacity modulation at the headend.

Abstract: Embodiments provide solutions to reduce power utilization (either at individual cable modems or in the overall network) in future cable modem networks. Particularly, embodiments seek to reduce power utilization at individual cable modems and in the overall network, by allocating upstream frequency bands and/or transmission modulation schemes among cable modems while accounting for cable loss experienced by individual upstream cable modem transmissions. According to embodiments, frequency spectrum and modulation scheme allocation techniques are provided to optimize power utilization and enable lower upstream transmission power by cable modems while maintaining similar signal strength of received signals or lower signal strength with reduced SNR requirements using lower capacity modulation at the headend.

Abstract: Embodiments provide techniques for high peak to average power ratio (PAPR) event mitigation in high speed data networks, such as cable networks, for example. Embodiments are applicable to multi-carrier and single-carrier modulation systems. Embodiments operate by predicting or detecting the occurrence of a peaking event at the transmitter, and then mitigating potential effects of the peaking event at the transmitter, including application of alternative constellation symbol mappings.

Abstract: Embodiments provide techniques for high peak to average power ratio (PAPR) event mitigation in high speed data networks, such as cable networks, for example. Embodiments are applicable to multi-carrier and single-carrier modulation systems. Embodiments operate by predicting or detecting the occurrence of a peaking event at the transmitter, and then mitigating potential effects of the peaking event at the transmitter, including application of alternative constellation symbol mappings.

Abstract: A communications receiver includes a noise analyzer to characterize the composition of the interference and/or distortion impressed onto a transmitted communications signal in the presence of one or more time-varying conditions. The noise analyzer may provide a selection signal indicating the composition of the interference and/or distortion impressed onto a transmitted communications signal in the presence of one or more time-varying conditions to be used by the communications receiver. In an exemplary embodiment, the communications receiver selects at least one set of filter coefficients to compensate for the interference and/or distortion impressed onto a transmitted communications signal in the presence of a particular time-varying interference and/or distortion condition.

Abstract: A method and apparatus is disclosed to compensate for impairments within a data converter such that its output is a more accurate representation of its input. The data converter includes a main data converter, a reference data converter, and a correction module. The main data converter may be characterized as having the impairments. As a result, the output of the main data converter is not the most accurate representation of its input. The reference data converter is designed such that the impairments are not present. The correction module estimates the impairments present within the main data converter using its output and the reference data converter to generate corrections coefficients. The correction module adjusts the output of the main data converter using the corrections coefficients to improve the performance of the data converter.

Abstract: Embodiments of a digital up-converter and an N-channel modulator are provided herein. The embodiments of the digital up-converter, in combination with the N-channel modulator, are capable of efficiently filling the spectrum of one or more RF signals with one or more types of information signals. For example, the digital up-converter can fill the spectrum of one or more RF signals with both broadcast and narrowcast video and data signals. In addition, the digital up-converter is capable of flexibly mapping the information signals to one or more channels of the one or more RF signals using a novel, three-level switching architecture.

Abstract: An apparatus is disclosed to compensate for non-linear effects resulting from the transmitter, the receiver, and/or the communication channel in a communication system. A receiver of the communication system contains an image cancellation module that compensates for images generated during the modulation and/or demodulation process. The image cancellation module includes a fine carrier correction loop to correct for frequency offsets between the transmitter and receiver. The image cancellation module includes a coarse acquisition mode and a decision directed mode. The decision directed mode allows for a larger signal-to-noise ratio for the receiver when compared against the coarse acquisition mode.

Abstract: A central entity and/or a remote device in a communication system are designed to address the problem of maintaining upstream synchronization in the remote device after loss of the downstream signal. One issue of particular importance is maintaining upstream transmissions from the remote device in an S-CDMA (or perhaps S-TDMA) mode that do not degrade performance of the communication system via poor upstream timing or a need for re-ranging. By providing novel functionality at the central entity for synchronizing first and second downstream signals and/or by providing novel functionality at the remote device for determining a symbol clock offset between a first terminated downstream signal and a second re-acquired downstream signal, embodiments of the present invention facilitate maintenance of synchronization through the loss of the downstream signal, thereby minimizing the need for re-ranging and avoiding poorly timed upstream bursts.

Abstract: Embodiments provide solutions to reduce power utilization (either at individual cable modems or in the overall network) in future cable modem networks. Particularly, embodiments seek to reduce power utilization at individual cable modems and in the overall network, by allocating upstream frequency bands and/or transmission modulation schemes among cable modems while accounting for cable loss experienced by individual upstream cable modem transmissions. According to embodiments, frequency spectrum and modulation scheme allocation techniques are provided to optimize power utilization and enable lower upstream transmission power by cable modems while maintaining similar signal strength of received signals or lower signal strength with reduced SNR requirements using lower capacity modulation at the headend.

Abstract: A method and apparatus is disclosed to compensate for impairments within a data converter such that its output is a more accurate representation of its input. The data converter includes a main data converter, a reference data converter, and a correction module. The main data converter may be characterized as having the impairments. As a result, the output of the main data converter is not the most accurate representation of its input. The reference data converter is designed such that the impairments are not present. The correction module estimates the impairments present within the main data converter using its output and the reference data converter to generate corrections coefficients. The correction module adjusts the output of the main data converter using the corrections coefficients to improve the performance of the data converter.

Abstract: A communications receiver includes a noise analyzer to characterize the composition of the interference and/or distortion impressed onto a transmitted communications signal in the presence of one or more time-varying conditions. The noise analyzer may provide a selection signal indicating the composition of the interference and/or distortion impressed onto a transmitted communications signal in the presence of one or more time-varying conditions to be used by the communications receiver. In an exemplary embodiment, the communications receiver selects at least one set of filter coefficients to compensate for the interference and/or distortion impressed onto a transmitted communications signal in the presence of a particular time-varying interference and/or distortion condition.

Abstract: A central entity and/or a remote device in a communication system are designed to address the problem of maintaining upstream synchronization in the remote device after loss of the downstream signal. One issue of particular importance is maintaining upstream transmissions from the remote device in an S-CDMA (or perhaps S-TDMA) mode that do not degrade performance of the communication system via poor upstream timing or a need for re-ranging. By providing novel functionality at the central entity for synchronizing first and second downstream signals and/or by providing novel functionality at the remote device for determining a symbol clock offset between a first terminated downstream signal and a second re-acquired downstream signal, embodiments of the present invention facilitate maintenance of synchronization through the loss of the downstream signal, thereby minimizing the need for re-ranging and avoiding poorly timed upstream bursts.

Abstract: Systems and methods are disclosed for detecting temporary high level impairments, such as noise or interference, for example, in a communications channel, and subsequently, mitigating the deleterious effects of the dynamic impairments. In one embodiment, the method not only performs dynamic characterization of channel fidelity against impairments, but also uses this dynamic characterization of the channel fidelity to adapt the receiver processing and to affect an improvement in the performance of the receiver. For example, in this embodiment, the method increases the accuracy of the estimation of the transmitted information, or similarly, increases the probability of making the correct estimates of the transmitted information, even in the presence of temporary severe levels of impairment. The channel fidelity history may also be stored and catalogued for use in, for example, future optimization of the transmit waveform.

Abstract: A central entity and/or a remote device in a communication system are designed to address the problem of maintaining upstream synchronization in the remote device after loss of the downstream signal. One issue of particular importance is maintaining upstream transmissions from the remote device in an S-CDMA (or perhaps S-TDMA) mode that do not degrade performance of the communication system via poor upstream timing or a need for re-ranging. By providing novel functionality at the central entity for synchronizing first and second downstream signals and/or by providing novel functionality at the remote device for determining a symbol clock offset between a first terminated downstream signal and a second re-acquired downstream signal, embodiments of the present invention facilitate maintenance of synchronization through the loss of the downstream signal, thereby minimizing the need for re-ranging and avoiding poorly timed upstream bursts.

Abstract: Methods and systems for DVB-C2 are disclosed and may include receiving data encoded utilizing variable encoding, variable modulation and outer codes via a physical layer matched to a desired quality of service. An error probability may be determined for said received data and retransmission of portions of said data with error probability above an error threshold may be requested. The variable modulation may include single carrier modulation, orthogonal frequency division modulation, synchronous code division multiple access, and/or from 256 QAM to 2048 QAM or greater. The variable encoding may include forward error correction code, which may include low density parity check code.

Abstract: Embodiments provide histogram-based methods and system to estimate the transfer function of an ADC, and subsequently to linearize a non-linear ADC transfer function. Embodiments include blind algorithms that require no a priori knowledge of the input signal distribution. Embodiments can be implemented using cumulative (i.e., cumulative distribution function (CDF)) or non-cumulative (i.e., probability density function (PDF)) histograms. According to embodiments, a non-linear transfer function can be estimated by linearly approximating successive local intervals of the transfer function. Linearly approximated successive local intervals of the transfer function can then be used to fully characterize and closely estimate the transfer function.

Abstract: Embodiments of a digital up-converter and an N-channel modulator are provided herein. The embodiments of the digital up-converter, in combination with the N-channel modulator, are capable of efficiently filling the spectrum of one or more RF signals with one or more types of information signals. For example, the digital up-converter can fill the spectrum of one or more RF signals with both broadcast and narrowcast video and data signals. In addition, the digital up-converter is capable of flexibly mapping the information signals to one or more channels of the one or more RF signals using a novel, three-level switching architecture.

Abstract: Embodiments provide techniques for high peak to average power ratio (PAPR) event mitigation in high speed data networks, such as cable networks, for example. Embodiments are applicable to multi-carrier and single-carrier modulation systems. Embodiments operate by predicting or detecting the occurrence of a peaking event at the transmitter, and then mitigating potential effects of the peaking event at the transmitter, including application of alternative constellation symbol mappings.

Abstract: Embodiments provide techniques for high peak to average power ratio (PAPR) event mitigation in high speed data networks, such as cable networks, for example. Embodiments are applicable to multi-carrier and single-carrier modulation systems. Embodiments operate by predicting or detecting the occurrence of a peaking event at the transmitter, and then mitigating potential effects of the peaking event at the transmitter, including application of alternative constellation symbol mappings.