US 5,694,474 A · Adaptive filter for signal processing and method therefor

Abstract

This invention is a component of an adaptive filter signal processor whose purpose is to separate a mixture of signals received by each of a plurality of transducers. This invention accomplishes a key step in that separation: it estimates, from the transducer signals, the relative propagation delays among the transducers for each source. First, it randomly generates a fixed number of sets of delay parameters, called a population. Thereafter, the following events occur at each clock cycle. Each set is processed by an instantaneous-performance calculator, to generate an instantaneous-performance value. The instantaneous performance value of each set is added to a cumulative performance value. The set with the greatest cumulative performance value is transferred to the adaptive filter signal processor. New parameter sets are generated at random. Whenever a parameter set is found whose instantaneous performance value exceeds that of the set in the population with the least instantaneous performance value, it is incorporated into the population. The set with the least cumulative performance value is deleted from the population, and the new parameter set is assigned an initial cumulative performance value that falls short of the greatest cumulative performance value in the population by a fixed amount.

Claims72

Dependent claims

A method of determining a set of a plurality of signal parameters for use in an adaptive filter signal processor to process a plurality of input signals to generate a plurality of processed signals, said method comprising:

a) generating a fixed plurality of sets;
b) storing said fixed plurality of sets;
c) generating a plurality of cumulative performance values, with a cumulative performance value corresponding to each of said fixed plurality of sets;
d) comparing said plurality of cumulative performance values,
e) choosing one of said plurality of cumulative performance values, based upon said comparison;
f) processing said plurality of input signals for a duration of time using one set, corresponding to said chosen one cumulative performance value, from said stored fixed plurality of sets to generate the plurality of processed signals;
g) generating a new set of a plurality of signal parameters;
h) generating a plurality of cumulative performance values for said new set and for each of said stored fixed plurality of sets;
i) comparing said plurality of cumulative performance values generated in step (h),
j) choosing one of said plurality of cumulative performance values generated in step (h), based upon the comparing step of (i);
k) based upon the comparing step of (i), either:
i) replacing one of said stored fixed plurality of sets, by said new set;
or
ii) deleting said new set;
l) processing said plurality of input signals for a duration of time using one set, corresponding to said chosen one cumulative performance value, from said stored fixed plurality of sets to generate the plurality of processed signals;
and
m) periodically reverting to steps (g)-(l).

14 more elements

A method of processing waves from a plurality of sources, comprising:

receiving said waves, including echoes and reverberations thereof, by a plurality of transducer means;
converting said waves, including echoes and reverberations thereof from said plurality of sources, by each of said plurality of transducer means into a signal, thereby generating a plurality of signals;
calculating a set of a plurality of signal parameters by:
generating a fixed plurality of sets of a plurality of signal parameters;
storing said fixed plurality of sets;
generating a plurality of instantaneous performance values for each set, with each instantaneous performance value generated at a different time;
combining said plurality of instantaneous performance values for each set to produce a plurality of cumulative performance values, with a cumulative performance value produced for each set;
storing said plurality of cumulative performance values;
periodically generating a new set of a plurality of signal parameters;
generating a new cumulative performance value, based upon said new set;
comparing said new cumulative performance value to said plurality of stored cumulative performance values;
based upon said comparing step, either:
i) replacing one of said stored plurality of cumulative performance values, by said new cumulative performance value, and the corresponding stored set by said new set;
or
ii) deleting said new cumulative value and said new set;
comparing said stored plurality of cumulative performance values;
choosing one of said stored plurality of cumulative performance values, based upon said comparison;
choosing one set, corresponding to said chosen one cumulative performance value;
supplying said chosen one set to a first processing means for operation thereon;
first processing said plurality of signals, using said chosen one set, corresponding to said chosen one cumulative performance value, to generate a plurality of first processed signals, wherein each of said first processed signals represents waves from one source, and a reduced amount of waves from other sources;
and then
secondly processing said plurality of first processed signals to generate a plurality of second processed signals, wherein in the presence of echoes and reverberations of said waves from said plurality of sources, each of said second processed signals represents waves from only one different source.

19 more elements

An adaptive filter for determining a set of a plurality of signal parameters for use in an adaptive filter signal processor to process a plurality of input signals to generate a plurality of processed signals, said filter comprising:

means for generating a fixed plurality of sets;
means for storing said fixed plurality of sets;
means for generating a plurality of cumulative performance values, based upon said fixed plurality of sets, with a cumulative performance value generated for each set;
means for evaluating said plurality of cumulative performance values, and choosing one of said plurality of cumulative performance values, based upon said evaluation;
and
means for processing said plurality of input signals for a duration of time using one set, corresponding to said chosen one cumulative performance value, from said fixed plurality of stored sets to generate the plurality of processed signals.

3 more elements

A signal processing system for processing waves from a plurality of sources, said system comprising:

a plurality of transducer means for receiving waves from said plurality of sources, including echoes and reverberations thereof and for generating a plurality of signals in response thereto, wherein each of said plurality of transducer means receives waves from said plurality of sources including echoes and reverberations thereof, and for generating one of said plurality of signals;
means for calculating a set of a plurality of signal parameters, said calculating means comprising:
means for generating a fixed plurality of sets of signal parameters;
means for storing said fixed plurality of sets of signal parameters;
means for generating a plurality of cumulative performance values, based upon said fixed plurality of sets of signal parameters, with a cumulative performance value generated for each set of signal parameters;
means for evaluating said plurality of cumulative performance values, and choosing one of said plurality of cumulative performance values, based upon said evaluation, and one of said sets of signal parameters corresponding to said one of said plurality of cumulative performance values chosen;
first processing means for receiving said plurality of signals, and said plurality of signal parameters of said set chosen for generating a plurality of first processed signals in response thereto, wherein each of said first processed signals represents waves from one source, and a reduced amount of waves from other sources;
and
second processing means for receiving said plurality of first processed signals and for generating a plurality of second processed signals in response thereto, wherein each of said second processed signals represents waves from only one source.

6 more elements

A signal processing system for processing waves from a plurality of sources, said system comprising:

a plurality of transducer means for receiving waves from said plurality of sources, including echoes and reverberations thereof and for generating a plurality of signals in response thereto, wherein each of said plurality of transducer means receives waves from said plurality of sources including echoes and reverberations thereof, and for generating one of said plurality of signals;
an adaptive filter for generating a plurality of signal parameters, said filter comprising:
means for generating a fixed plurality of sets of signal parameters;
means for storing said fixed plurality of sets of signal parameters;
means for generating a plurality of cumulative performance values, based upon said fixed plurality of sets of signal parameters, with a cumulative performance value generated for each set;
means for evaluating said plurality of performance values, and choosing one of said plurality of performance values and its corresponding set of plurality of signal parameters, based upon said evaluation;
first processing means for receiving said plurality of signals and said plurality of signal parameters and for generating a plurality of first processed signals in response thereto, wherein in the absence of echoes and reverberations of said waves from said plurality of sources, each of said first processed signals represents waves from only one different source;
and
second processing means for receiving said plurality of first processed signals and for generating a plurality of second processed signals in response thereto, wherein in the presence of echoes and reverberations of said waves from said plurality of sources, each of said second processed signals represents waves from only one source.

6 more elements

An adaptive filter signal processing system for processing waves from a plurality of sources, said system comprising:

a plurality of transducer means for receiving waves from said plurality of sources, including echoes and reverberation thereof and for generating a plurality of signals in response thereto, wherein each of said plurality of transducer means receives waves from said plurality of sources including echoes and reverberations thereof, and for generating one of said plurality of signals;
an adaptive filter for generating a plurality of signal parameters, said filter comprising:
means for generating a fixed plurality of sets of signal parameters;
means for storing said fixed plurality of sets signal parameters;
means for generating a plurality of performance values, based upon said fixed plurality of sets of signal parameters, with a performance value generated for each set;
means for evaluating said plurality of performance values, and choosing one of said plurality of performance values, and its corresponding set of signal parameters, based upon said evaluation;
first processing means comprises a beamformer for receiving said plurality of signals and said plurality of signal parameters, and for generating a plurality of first processed signals in response thereto, wherein each of said first processed signals represents waves from one source, and a reduced amount of waves from other sources;
and
second processing means for receiving said plurality of first processed signals and for generating a plurality of second processed signals in response thereto, wherein each of said second processed signals represent waves from only one source.

6 more elements

Dependencies are inferred from the claim text.

Adaptive filter for signal processing and method therefor

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Adaptive filter for signal processing and method therefor

Life of this patent

Abstract

Claims72