Density function centric signal processing

Patent metadata

Field	Value
Publication number	US-10659095-B2
Application number	US-201715712768-A
Country	US
Kind code	B2
Filing date	Sep 22, 2017
Priority date	Nov 21, 2012
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

A circuit for direct current (DC) offset estimation comprises a quantile value circuit and a signal processor. The quantile value circuit determines a plurality of quantile values of an input signal and includes a plurality of quantile filters. Each quantile filter includes a comparator, a level shifter, a monotonic transfer function component, and a latched integrator. The comparator compares the input signal and a quantile value. The level shifter shifts the output of the comparator. The monotonic transfer function component determines the magnitude of the shifted signal and provide a transfer function signal. The latched integrator suppresses transient characteristics of the transfer function signal and provide the quantile value. The signal processor is configured to calculate a weighted average of the quantile values to yield a DC offset estimate.

First claim

Having thus described various embodiments of the invention, what is claimed as new and desired to be protected by Letters Patent includes the following:

1. An apparatus for classifying a signal as one of noise and a predetermined type of event comprising a plurality of symbols subjected to predetermined channel noise regimes, each regime represented by one or more of a plurality of temporal attributes, the apparatus comprising:
a receiver configured to estimate a density function of the signal and sample the density function at a plurality of points; and
a signal processor connected to the receiver and configured to
determine a maximum number of the regimes and a minimum number of the regimes through a clustering technique,
initialize a plurality of clusters corresponding to the plurality of sampled points, based upon the maximum and minimum numbers,
process, through a clustering technique, a signal value corresponding to each of the regimes by updating parameters maintained for a cluster of the plurality of clusters,
calculate a plurality of statistical values from the updated parameters, and
classify the signal based upon the plurality of statistical values and the updated parameters.

2. The apparatus of claim 1 , wherein the receiver includes a plurality of sensors, each sensor configured to sample a waveform of the density function at a different point on the waveform.

3. The apparatus of claim 2 , wherein each sensor is further configured to sample the density function at a different frequency.

4. A method of classifying a signal as one of noise and a predetermined type of event comprising a plurality of symbols subjected to predetermined channel noise regimes, each regime represented by one or more of a plurality of temporal attributes, the method comprising the steps of:
estimating a density function of the signal;
sampling the density function at a plurality of points;
determining a maximum number of the regimes and a minimum number of the regimes through a clustering technique;
initializing a plurality of clusters corresponding to the sampled points, based upon the maximum and minimum numbers;
processing, through a clustering technique, a signal value corresponding to each of the regimes by updating parameters maintained for a cluster;
calculating a plurality of statistical values from the parameters maintained for the clusters; and
classifying the signal based upon the plurality of statistical values and the parameters.

5. The method of claim 4 , wherein the density function includes a probability density function or a cumulative distribution function.

Assignees

• Alarm Com Inc

Inventors

• Briancon Alain Charles
• Epard Marc Anthony
• Lutes Robert Leon
• Lancaster John Berns
• Johnson Jerald Frederic
• Kabler Ronald Byron

Classifications

• H04B1/30 Primary

  for homodyne or synchrodyne receivers (demodulator circuits H03D1/22) · CPC title

• H04B2001/305

  using DC offset compensation techniques · CPC title