Echelon Corporation

Echleon Corporation

Walter J Downey

Philip H Sutterlin

Amy O Hurlbut

Mark Adrian Stubbs

Luna Chen

J Marcus Stewart

Glen Meyers Riley

Benjamin W Chui

Robert A Dolin

Leonid Ovanesyan

Jacques H Wilson, Ii

Jacques H Ii Wilson

Methods and systems are disclosed for applying an interleaver that better distributes signal errors to be used in devices operating on low voltage power grids. One embodiment of a method comprises: determining a frequency cycle of the communication medium; setting an interleaver block size based on the frequency cycle of the communication medium; re-arranging bits in a data packet based on the interleaver block size; transmitting the re-arranged data packet over the communication medium to a receiver. Specifically, according to an embodiment, the interleaver block size is set to one-half of the frequency cycle of the communication medium.

Methods and systems for applying an improved interleaver for modems operating on power grid

Systems, methods, and apparatuses are disclosed for choosing the modulation mode using packets transmitted by a sender to a receiver, wherein the packets contain data patterns unknown to the receiver. In some embodiments, the sender sends of a data packet in the most robust mode available, such that the packet can be correctly received by the receiver under even the noisiest conditions. The data contained in the packet is demodulated and decoded. A cyclic redundancy check is performed to ensure that the resultant data is error-free. Once the transmitted payload data is known, the original error coding can be re-applied to the payload data to produce the transmitted bit stream. Comparison of the demodulated bit stream to the regenerated transmitted bit stream yields the pattern of errors. The pattern of errors is analyzed and a higher throughput decoding scheme is chosen based on the results of the analysis.

Modulation adaption method for multi-mode modems

A method is disclosed for detecting packet at a receiving system in a Multi-Carrier Modulation (MCM) system. The method starts with receiving a signal at the receiving system. Then during the plurality of symbol durations, a set of phases of the signal for each symbol duration is obtained, where each phase is a phase of a carrier of the number of carriers. Then a set of phase variances for each carrier of the number of carriers is obtained, where each phase variance is a difference of phases of a carrier in different symbol durations. Then a phase variance value based on the set of phase variances is computed and it is compared with a threshold to determine whether a packet has been detected from the received signal.

Method and apparatus for phase-based multi-carrier modulation (MCM) packet detection

A method implemented in a device is disclosed for networking through signals transmitted across a shared medium network. The method starts with monitoring for a first signal on a shared medium of the shared medium network. The first signal is processed after it is received and while the first signal is being processed, a set of one or more signals is received on the shared medium. Then a set of one or more amplitude increases is determined, where each amplitude increase is from an earlier received signal to a later received signal. The set of one or more amplitude increases is compared to a threshold value and at least partially in response to the comparison, the device discards one or more signals from the first signal and the set of one or more signals.

Method and system of enhancing signal processing in a shared medium network

Embodiments of the invention include an apparatus for performing Galois multiplication using an enhanced Galois table. Galois multiplication may include converting a first and second multiplicand to exponential forms using a Galois table, adding the exponential forms of the first and second multiplicands, and converting the added exponential forms of the first and second multiplicands to a decimal equivalent binary form using the Galois table to decimal equivalent binary result of the Galois multiplication.

Method and system of improved galois multiplication

A method is disclosed for detecting packet at a receiving system in a Multi-Carrier Modulation (MCM) system. The method starts with receiving a signal at the receiving system. Then a deviation value of the signal is computed, where the deviation value is computed at least partially based on phase differences between some number of carriers in the preamble. The deviation value is compared with a threshold to determine whether a packet has been detected from the received signal. In response to the determination that a packet has been detected, a symbol offset is computed optionally, where the symbol offset indicates a number of sample points from a beginning of a symbol.

Method and apparatus for multi-carrier modulation (MCM) packet detection based on phase differences

Embodiments of an improved Galois multiplication route are described. In some embodiments, the Galois multiplication routine looks up and retrieves a first value corresponding to an address in the Galois table, exclusive ORs the retrieved value with a data value from a data set to generate an intermediate address for the Galois table, wherein the data value is at a location associated with an index, and looks up and retrieves a second value in the Galois table by the intermediate address.

Method and system of improved reed-solomon decoding

Method and system of improved Galois multiplication

A circuit for use with a power supply coupled in a switched leg of, for example, a lighting circuit, is described. The circuit provides a low impedance near the zero crossing of the AC signal and a high impedance thereafter, thereby allowing the power supply to draw current that bypasses, for instance, a light bulb.

Circuit for use with switched leg power supply

An improvement in a buffer for driving a signal onto a power line is described. The buffer includes a second order filter. With the improvement, the collector-to-emitter potential of an emitter follower is maintained constant to substantially reduce the distortion associated with base-collector capacitance.

Input/output buffer incorporating filter for powerline communications line

A method and apparatus for defining and generating a digital waveform such as used for the local oscillator for a down converter in a receiver is disclosed. The method and apparatus is particularly useful where the digital waveform is not an integer submultiple of a reference signal. A plurality of different digital waveforms meeting the timing criteria but having different combinations of segments needed to meet the timing criteria are generated. Each of the digital waveforms so generated are tested in, for instance, a receiver to enable the selection of the best combination of segments.

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Los Gatos, CA, United States of America

Walter J Downey