Motorola Corporation

Michael F Durkin

Robert Henry Bickley

David Moon Yee

Philip John Zucarelli

Theodore Woolley Keller

James H Stilwell

Taul Eric Aragaki

Russell D Thomas

Michael Y Weidner

Utility consumption data is provided over power line carrier links to local nodes and routed through a network of local nodes over peer-to-peer line-of-sight RF links to a utility service provider. Backhauler nodes combine the utility consumption data from the local nodes within a coverage region for routing to the utility service provider. Consumer nodes include sensing elements for measuring the utility consumption data, and switching elements for connecting or disconnecting the utility from a consumer location. Messages are sent through the network requesting the utility consumption data and for activating the switching elements.

Data transfer system and method for communicating utility consumption data over power line carriers

A symbol state trellis maximum likelihood detection method greatly limits the number of possible interfering symbols which require examination. This method has considerable processing advantages over other optimal maximum likelihood detection methods. For practical configurations, the symbol state trellis maximum likelihood detection method provides a performance which is less than 1 dB from the optimal maximum likelihood detection method while simultaneously providing for a similar bit error rate. The symbol state trellis maximum likelihood detection method calculates the phase errors for all paths from a present state to a previous state. Next, total path distances are calculated for previously selected paths to the previous state. The phase error associated with each of the paths from two states previous to the present state are calculated. For each symbol of the present state, only one path is selected to each symbol. This path corresponds to the path with the minimum phase error. The symbol sent may then be determined by retracing the selected paths through the trellis structure for each of the M symbols.

Symbol state trellis maximum likelihood detection method

An apparatus for performing a soft decision function prior to convolutional decoding in a data communication system using differential quadrature-PSK or other transmission schemes is disclosed. A memory element coupled between a demodulator and the convolutional decoder in a receiver portion of the communications system performs the soft decision function. The memory element contains data organized using probability of occurrence and Log-Likelihood parameters for each potential combination of current and past received signal modulation quantized at a predetermined level.

Soft decision digital communication apparatus

Growing community of inventors

Scottsdale, AZ, United States of America

Michael F Durkin