Method and apparatus for resolving multipath components for wireless location finding

A method for resolving multipath components of a signal of interest, comprising:

• applying a received signal to a matched filter bank and generating matched filter outputs;
• obtaining a power delay profile of the received signal from said matched filter outputs;
• determining a first cost by adding the values of the power delay profile corresponding to a range of delay indices;
• determining a second cost by summing time averaged products of the matched filter outputs;
• determining a difference between the first and second costs;
• comparing said difference to a threshold to obtain a threshold comparison;
• detecting existence of multipath components as a function said threshold comparison;
• and
• estimating multipath delays associated with detected multipath components.

A method for resolving multipath components of a signal of interest, comprising:

• applying a received signal to a matched filter bank and generating matched filter outputs;
• and
• estimating multipath components from said matched filter output with an adaptive filter, said adaptive filter having a weight vector;
• applying successive projections to the adaptive filter weight vector hi at every iteration, wherein said successive projections are based on the combination of information obtained by
• (i) extracting, by non-coherently averaging the output of the matched filter bank, information about the channel region of support and maximum amplitude,
• (ii) detecting the existence of overlapping multipath components and estimating their number, and
• (iii) estimating the detected multipath components time and amplitude of arrival by transforming the output of the matched filter bank into the frequency domain to obtain a three dimensional power-delay-frequency profile;
• and
• successively projecting the adaptive filter weight vector on the set of all possible elements satisfying the constraints obtained from steps (i) through (iii), iterating the adaptive filter weight vector until it reaches steady state, and averaging the weight vector non-coherently.

An apparatus for resolving multipath components of a signal of interest, comprising:

• a matched filter bank configured for filtering a received signal and generating matched filter outputs;
• a non-coherent averaging stage configured for obtaining a power delay profile of the received signal from said matched filter outputs;
• and
• means for carrying out the operations of
• determining a first cost as a function of the power delay profile;
• determining a second cost as a function of the matched filter outputs;
• determining a difference between the first and second costs;
• comparing said difference to a threshold to obtain a threshold comparison;
• and
• detecting the existence of multipath components as a function said threshold comparison.

An apparatus for resolving multipath components of a signal of interest, comprising:

• a matched filter bank configured for filtering a received signal and generating matched filter outputs;
• a non-coherent averaging stage configured for obtaining a power delay profile of the received signal from said matched filter outputs;
• and
• means for carrying out the operations of
• determining a first cost by adding the values of the power delay profile corresponding to a range of delay indices;
• determining a second cost by summing time averaged products of the matched filter outputs;
• determining a difference between the first and second costs;
• comparing said difference to a threshold to obtain a threshold comparison;
• detecting the existence of multipath components as a function said threshold comparison;
• and
• estimating multipath delays associated with detected multipath components.

An apparatus for resolving multipath components of a signal of interest, comprising:

• a matched filter bank configured for filtering a received signal and generating matched filter outputs;
• an adaptive filter configured for estimating multipath components from said matched filter output, said adaptive filter having a weight vector;
• and
• means for carrying out the operations of
• applying successive projections to the adaptive filter weight vector at every iteration, wherein said successive projections are based on the combination of information obtained by
• (i) extracting, by non-coherently averaging the output of the matched filter bank, information about the channel region of support and maximum amplitude,
• (ii) detecting the existence of overlapping multipath components and estimating their number, and
• (iii) estimating the detected multipath components time and amplitude of arrival by transforming the output of the matched filter bank into the frequency domain to obtain a three dimensional power-delay-frequency profile;
• and
• successively projecting the adaptive filter weight vector on the set of all possible elements satisfying the constraints obtained from steps (i) through (iii), iterating the adaptive filter weight vector until it reaches steady state, and averaging the weight vector non-coherently.