Patent application number | Description | Published |
20120182162 | Rollover operative digital to analog converter (DAC) - Rollover operative digital to analog converter (DAC). With respect to a codeword that is provided to a DAC, a processing module (e.g., a rollover processor) operates to compare the codeword to threshold(s) in accordance with adaptively partitioning the codeword into one or more sub-codewords when the codeword has a magnitude greater than at least one of the thresholds. In instances that the codeword is less than a threshold, the codeword may be provided directly to a DAC for use in generating a first analog signal. However, if the codeword is a larger than a threshold, then that portion of the codeword which is greater than the threshold may be provided to an alternative component such as one or more auxiliary or additional DACs, one or more other circuitry components, etc. in accordance with generating at least one additional analog signal to be combined with the first analog signal. | 07-19-2012 |
20120230383 | Linear distortion and interference estimation using decision feedback equalizer coefficients - Linear distortion and interference estimation using decision feedback equalizer coefficients. Processing of different respective groups of equalizer coefficients may be made to determine the residual frequency response of an equalizer and/or device in which the equalizer is implemented. Such an equalizer may be in woman within any of a number of respective communication devices including those operative within satellite, wireless, wired, fiber-optic, and/or mobile communication systems. A first group of equalizer coefficients corresponds to certain filtering characteristics of the equalizer and/or device in which the equalizer is implemented. The equalizer is implemented to process a signal to generate a second group of equalizer coefficients. Processing and/or analysis of the first group of equalizer coefficients and the second group of equalizer coefficients will generate a third group of equalizer coefficients corresponding to the residual frequency response of the equalizer and/or device in which the equalizer is implemented. | 09-13-2012 |
20120230385 | Narrowband ingress estimation and characterization using equalizer taps - Narrowband ingress estimation and characterization using equalizer taps. A equalizer including a feed forward equalizer (FFE) and a decision feedback equalizer (DFE) is implemented to process an input signal thereby generating an output signal. Analysis of the frequency response of the equalizer including the FFE and the DFE of the equalizer allows for the determination of whether or not narrowband ingress exists within the signal received by the equalizer. For example, analysis of the signal output from the equalizer provides for determination of the overall frequency response of the equalizer. In addition, analysis of the respective equalizer coefficients within one or both of the FFE and the DFE of the equalizer may be used to determine the overall frequency response of the equalizer. Narrowband ingress may be identified when the combination of the FFE (having a notch therein) and the DFE provides for an overall flat frequency response. | 09-13-2012 |
20120243527 | Upstream burst noise measurement and characterization - Upstream burst noise measurement and characterization. One or more communication devices is implemented to detect and measure burst noise event(s) within channel(s) associated with communication link(s) within communication system(s) or network(s). Detection and measurement of a burst noise event may be made during active communications on one or more other channels, and may be made during active communications on two channels respectively adjacent to the channel on which the burst noise event is being detected and measured. The channel on which the burst noise event is detected and measured may be an unused channel. The detection and measurement of the burst noise event may be made during a quiet time slot within one of the channels. Correlation (e.g., with respect time) may be determined with respect to different respective layers within a communication device (e.g., with respect to MAC and PHY layers). | 09-27-2012 |
20120243597 | Upstream frequency response measurement and characterization - Upstream frequency response measurement and characterization. Signaling is provided between respective communication devices within a communication system. Based upon at least one of these signals, one of the communication devices captures a number of sample sets corresponding thereto at different respective frequencies (e.g., a different respective center frequencies, frequency bands, etc.). Then, spectral analysis is performed with respect to each of the sample sets to generate a respective and corresponding channel response estimate there from. After this number of channel response estimates is determined, they are combined or splice together to generate a full channel response estimate. In implementations including an equalizer, different respective sample sets may correspond to those that have undergone equalization processing and those that have not. | 09-27-2012 |
20120243648 | Characterization and assessment of communication channel average group delay variation - Characterization and assessment of communication channel average group delay variation. A signal having repeated signal components therein is received by a communication device, and that signal undergoes appropriate processing to determine respective amplitude and phase of a number of frequency bins. The phase difference from bin to bin (including respecting unwrapping, and proper normalization) is used to determine the group delay of a communication channel, or portion thereof, as a function of frequency. Multiple respective group delay measurements may be averaged to generate a wideband group delay of the communication channel as a function of frequency. Overlap between different respective band-edge portions of the communication channel may assist in generating a seamless continuous wideband spectrum estimation for use in determining the wideband group delay of the communication channel. | 09-27-2012 |
20120243865 | Detection and characterization of laser clipping within communication devices - Detection and characterization of laser clipping within communication devices. Identification of one or more harmonics associated with a fundamental frequency by which signaling is effectuated within the communication system for laser clipping identification. Appropriate spectral signal analysis is made to identify the presence of characteristic(s) (e.g., energy, amplitude, phase, and/or other characteristic(s)), if any, at one or more harmonic frequencies within a received signal. Appropriate time correlation is performed to distinguish whether or not characteristic(s) associated with at one or more of these harmonic bands is a result of laser clipping or from some other source (e.g., such as other signals within a communication system that happened to reside at those respective harmonic bands). Such appropriate identified correlation between characteristic(s) corresponding to a fundamental frequency band of the communication signal and characteristic(s) corresponding to one or more harmonics (e.g., of that fundamental frequency band) indicates laser clipping. | 09-27-2012 |
20130064323 | Turbo Coding for Upstream and Downstream Transmission in Cable Systems - A method of transmitting data in a cable modem system includes the steps of encoding the data using forward error correction. The data is then encoded with Turbo encoding. The data is then sent to a modulation scheme. The data is then transmitted over a cable channel. The data is then demodulated. The data is then decoded using a Turbo decoder. An inverse of the forward error correction is then applied to the data. | 03-14-2013 |
20130215953 | Measurement of intermodulation products of digital signals - Measurement of intermodulation products of digital signals. One or more devices, within a communication system, having and analog to digital converter (ADC) with a sufficiently wide frequency response as to capture not only a signal of interest, but many other signals simultaneously, allows for appropriate signal processing of such captured samples to identify one or more intermodulation products that may exist as a function of the relationship of one or more frequencies. For example, composite second order (CSO) or composite triple beat (CTB), or even higher ordered signals, may occur within various communication systems. These effects may be caused by any of a number of sources including nonlinearities in the system, such as affects associated with laser clipping, amplifier compression, corroded connectors, etc. Appropriate processing is performed determine the existences of such intermodulation product signals, and, if desired, subsequent signal processing and/or fixing of such effects therein is performed. | 08-22-2013 |
20130222161 | Distortion and aliasing reduction for digital to analog conversion - Distortion and aliasing reduction for digital to analog conversion. Synthesis of one or more distortion terms made based on a digital signal (e.g., one or more digital codewords) is performed in accordance with digital to analog conversion. The one or more distortion terms may correspond to aliased higher-order harmonics, distortion, nonlinearities, clipping, etc. Such distortion terms may be known a priori, such as based upon particular characteristics of a given device, operational history, etc. Alternatively, such distortion terms may be determined based upon operation of a device and/or based upon an analog signal generated from the analog to conversion process. For example, frequency selective measurements made based on an analog signal generated from the digital to analog conversion may be used for determination of and/or adaptation of the one or more distortion terms. One or more DACs may be employed within various architectures operative to perform digital to analog conversion. | 08-29-2013 |
20130230130 | DISTORTION AND ALIASING REDUCTION FOR DIGITAL TO ANALOG CONVERSION - Distortion and aliasing reduction for digital to analog conversion. Synthesis of one or more distortion terms made based on a digital signal (e.g., one or more digital codewords) is performed in accordance with digital to analog conversion. The one or more distortion terms may correspond to aliased higher-order harmonics, distortion, nonlinearities, clipping, etc. Such distortion terms may be known a priori, such as based upon particular characteristics of a given device, operational history, etc. Alternatively, such distortion terms may be determined based upon operation of a device and/or based upon an analog signal generated from the analog to conversion process. For example, frequency selective measurements made based on an analog signal generated from the digital to analog conversion may be used for determination of and/or adaptation of the one or more distortion terms. One or more DACs may be employed within various architectures operative to perform digital to analog conversion. | 09-05-2013 |
20130239164 | Method and system for Digital Video Broadcast for Cable (DVB-C2) - 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. | 09-12-2013 |
20130279560 | Asymmetric Multi-Channel Adaptive Equalizer - 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. | 10-24-2013 |
20130286855 | Spectrum analysis capability in network and/or system communication devices - Spectrum analysis (SA) capability is included in various communication devices within a communication network. One or more of the devices use the SA information from other devices in the system to determine status of various communication links were devices in the system. One or more processors within one or more devices can identify any actual/existing or expected failure or degradation of the various components within the system. Such components may include communication devices, communication channels or links, interfaces, interconnections, etc. When an actual/existing or expected failure or degradation is identified, the affected components may be serviced or devices within the system may operate to mitigate any reduction in performance caused by such problems. Such SA functionality/capability may be implemented in one communication device or in a distributed manner across a number of devices in a communication system. | 10-31-2013 |
20140003545 | Signal processing under attenuated transmission conditions | 01-02-2014 |
20140079103 | Interference cancellation within OFDM communications - Many communication systems operate based on orthogonal frequency division multiplexing (OFDM) signaling and/or orthogonal frequency division multiple access (OFDMA) signaling. Within such systems, narrowband interference, which may alternatively be referred to as narrowband ingress, narrowband ingress interference, narrowband noise, etc., may adversely affect one or more subcarriers or tones causing a reduction in performance or even link failure. Such narrowband interference may affect only one or a relatively few tones employed within such communications. When the narrowband interference is identified, a transmission may then be made including one or more information-free tones. A device that receives such a transmission then uses those information-free tones to reduce or cancel the narrowband interference. Such processing may be performed in the frequency-domain, the time domain, or both. | 03-20-2014 |
20140177750 | Fine step blended modulation communications - A communication device is configured to perform symbol mapping of bits to generate modulation symbols using one or more modulations. The device may employ a blended modulation composed of bit labels or symbols having different numbers of bits per symbol and different modulations. For example, the device may symbol map bit labels/symbols having first number of bits per symbol to first modulation, and the device may symbol map labels/symbols having second number of bits per symbol to second modulation. The device may be configured to perform forward error correction (FEC) or error correction code (ECC) and coding of information bits to generate coded bits that subsequently undergo symbol mapping. The device may be configured to operate based on different operational modes based on substantially uniform steps of rates, or bits per symbol, and energy per bit or symbol to noise spectral density ratio (E | 06-26-2014 |
20150078194 | Spectrum analysis capability in network and/or system communication devices - Spectrum analysis (SA) capability is included in various communication devices within a communication network. One or more of the devices use the SA information from other devices in the system to determine status of various communication links were devices in the system. One or more processors within one or more devices can identify any actual/existing or expected failure or degradation of the various components within the system. Such components may include communication devices, communication channels or links, interfaces, interconnections, etc. When an actual/existing or expected failure or degradation is identified, the affected components may be serviced or devices within the system may operate to mitigate any reduction in performance caused by such problems. Such SA functionality/capability may be implemented in one communication device or in a distributed manner across a number of devices in a communication system. | 03-19-2015 |