Patent application number | Description | Published |
20080215268 | Signal Outage Detection - Disclosed are various embodiments for outage detection. In one embodiment, an outage detection system includes a signal sampler configured to sample a signal on a communications link and to determine a noise level and a signal level of the sample. An outage detection system also includes a comparator configured to compare a critical value with a sum of signal and noise of the sample. An outage detection system further includes a binomial probability analyzer configured to calculate a binomial probability of false outage of the sample and the previous N samples. | 09-04-2008 |
20080304595 | DSP workload distribution in a power line carrier system - Disclosed are various embodiments for dividing workload in a digital signal processing system. In one embodiment, the system includes at least one analog-to-digital converter configured to receive a three phase analog waveform and a digital waveform. The system can also include a first DSP configured to interface with an external computer and a second DSP configured to receive the digital waveform and isolate a specified frequency range. The system can also include a plurality of DSP's configured to extract specified channels from the specified frequency range and output the extracted channel data. | 12-11-2008 |
20080307136 | Arbitration of Memory Transfers in a DSP System - Disclosed are various embodiments for arbitration of memory transfers in a digital signal processing system. In one embodiment, a digital signal processing system includes a plurality of DSP's having an external memory. The DSP's are further configurable to act as a master processor and a slave processor relative to another DSP. The system also includes an arbiter configured to maintain DSP status data and arbitrate requests between master processors and slave processors in the system. | 12-11-2008 |
20090110121 | Programmable Signal Slicer - Disclosed are various embodiments of a programmable slicer in a digital signal processing system and/or software radio system. In one embodiment, a plurality of demodulation schemes and a plurality of channel definitions are stored in a channel allocation table. An analog waveform is received and converted into at least one digital waveform. A specified frequency range is isolated from the at least one digital waveform. The magnitude of tones within the specified frequency range is measured and stored in a signal magnitude table. Symbols and/or bits are decoded from the signal magnitude table by applying a demodulation schemes and channel definitions to the magnitudes stored in the signal magnitude table. | 04-30-2009 |
20090147863 | Input signal combiner system and method - Disclosed are various embodiments of an input signal combiner. In one embodiment, a receive stage receives a multi-phase waveform and separates the multi-phase waveform into a plurality of waveforms. Analog-to-digital converters convert the plurality of analog waveforms into at least one digital signal. At least one gain stage adjusts an amplitude of each of the digital signals and combines the amplitude adjusted digital signals into at least one gain adjusted combined signal. A signal extraction stage extracts an inbound signal from the at least one gain adjusted combined signal according to a demodulation scheme. | 06-11-2009 |
20100164615 | System And Method For Relative Phase Shift Keying - Disclosed are various embodiments of systems and methods for relative phase shift keying. In one embodiment, an analog waveform is converted to digital signals. A specified frequency range is isolated and the magnitudes of tones corresponding to a channel are measured. The relative phase of a subset of the tones having the greatest magnitude is measured and a relative phase component is generated. At least one symbol is associated with the subset of tones and the relative phase component. | 07-01-2010 |
20110249678 | DYNAMIC MODULATION SELECTION - Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for transmitting data. In one aspect, a method obtains a baseline data rate for transmissions from a node that are received over a channel of a power line communications system and a set of available modulation techniques for the node. The set of available modulation techniques can include at least two modulation techniques with which the node is configured to encode data that are transmitted over the channel. Using the set of available modulation techniques, a modulation technique that is capable of providing at least the baseline data rate with at least a threshold confidence for the node is selected. In turn, data is provided to the node specifying the selected modulation technique. | 10-13-2011 |
20120084559 | Communications Source Authentication - Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for authenticating a communications source. In one aspect, a method includes decrypting a symbol that was received over a particular communications channel. The symbol is decrypted using a decryption key that is assigned to a particular endpoint that is assigned the particular communications channel. A measure of error is computed for the decrypted symbol. In turn, a determination is made whether the measure of error exceeds a threshold error measure. If the measure of error does not exceed the threshold error measure the decrypted symbol is identified as a valid symbol transmitted by the particular endpoint, and logged as such. If the measure of error exceeds the threshold error measure, the decrypted symbol is identified as a symbol from a different endpoint; and | 04-05-2012 |
20120106664 | Variable Symbol Period Assignment And Detection - Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for dynamically selecting symbol periods for communications signals and recovering symbols from the communications signals. In one aspect, a method includes receiving a plurality of communications signals over a plurality of different communications channels and determining symbol period end times for the communications signals. A determination is made that a present time is coincident with an end of a sample period for the communications signals and that an end of the symbol period for the communications signals received over at least one of the communications channels is coincident with the present time. In turn, data are provided that represent a symbol received over each communications channel for which an end of the symbol period is coincident with the present time. | 05-03-2012 |
20130163681 | COORDINATING POWER DISTRIBUTION LINE COMMUNICATIONS - Aspects of the present disclosure are also directed towards a method that includes maintaining a transmission period which has a start time and an end time synchronized to metrological time. Further, this method, in response to the start time, begins transmission of a frame, which includes a plurality of symbols. This transmission occurs over power distribution lines that carry power using alternating current (AC). This method also includes synchronizing a transmission time for each symbol of the plurality of symbols according to a time-based parameter of the AC. In response to reaching an end of the frame, a synchronization symbol period is determined for a synchronization symbol, as a function of the transmission times, for the plurality of symbols and time from the end of the frame to the end time. The synchronization symbol is then transmitted on the power distribution lines. | 06-27-2013 |
20140001845 | POWER LOAD CONTROL WITH DYNAMIC CAPABILITY | 01-02-2014 |
20140064387 | POWER DISTRIBUTION LINE COMMUNICATIONS WITH COMPENSATION FOR POST MODULATION - A system for communicating data over power utility lines includes a plurality of endpoint devices. The endpoint devices can have modulation circuits configured and arranged to modulate data using multiple-orthogonal frequency sub-channels. The endpoint devices can also have a power line interface circuit configured and arranged to transmit the modulated data over a power utility line. A detection module can be configured and arranged to detect undesirable post modulation of a communication from one of the plurality of endpoint devices and to generate a signal responsive to the detected post modulation. The endpoint devices can then set a spacing between the multiple orthogonal frequency sub-channels in response to the signal responsive to the detected post modulation. | 03-06-2014 |
20140126720 | Power-Line Communications with Communication Channel To And/Or From Endpoint Circuits with Authentication Methodology - Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for authenticating a communications source. In one aspect, a method includes decrypting a symbol that was received over a particular communications channel. The symbol is decrypted using a decryption key that is assigned to a particular endpoint that is assigned the particular communications channel. A measure of error is computed for the decrypted symbol. In turn, a determination is made whether the measure of error exceeds a threshold error measure. If the measure of error does not exceed the threshold error measure the decrypted symbol is identified as a valid symbol transmitted by the particular endpoint, and logged as such. If the measure of error exceeds the threshold error measure, the decrypted symbol is identified as a symbol from a different endpoint; and | 05-08-2014 |
20140192906 | DYNAMIC MODULATION SELECTION - Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for transmitting data. In one aspect, a method obtains a baseline data rate for transmissions from a node that are received over a channel of a power line communications system and a set of available modulation techniques for the node. The set of available modulation techniques can include at least two modulation techniques with which the node is configured to encode data that are transmitted over the channel. Using the set of available modulation techniques, a modulation technique that is capable of providing at least the baseline data rate with at least a threshold confidence for the node is selected. In turn, data is provided to the node specifying the selected modulation technique. | 07-10-2014 |
20140211867 | COORDINATING POWER DISTRIBUTION LINE COMMUNICATIONS - Aspects of the present disclosure are also directed towards a method that includes maintaining a transmission period which has a start time and an end time synchronized to metrological time. Further, this method, in response to the start time, begins transmission of a frame, which includes a plurality of symbols. This transmission occurs over power distribution lines that carry power using alternating current (AC). This method also includes synchronizing a transmission time for each symbol of the plurality of symbols according to a time-based parameter of the AC. In response to reaching an end of the frame, a synchronization symbol period is determined for a synchronization symbol, as a function of the transmission times, for the plurality of symbols and time from the end of the frame to the end time. The synchronization symbol is then transmitted on the power distribution lines. | 07-31-2014 |
20150067431 | DATA RECOVERY OF DATA SYMBOLS RECEIVED IN ERROR - In one or more embodiments, a data processing apparatus is configured to receive data symbols transmitted from one or more endpoint devices. Each of the data symbols is transmitted in a respective temporal position assigned for communication by one of the plurality of endpoints. The data processing apparatus is configured to recover data from two or more transmission(s)/retransmission(s) (of the same data) that are received in error and have different temporal positions. The corresponding data symbols in error are phase-aligned per a common reference point and energy is accumulated therefrom. The data processing apparatus discerns correct data values from the accumulated energy. | 03-05-2015 |