US 2003/0156665 A1 · Extracting fine-tuned estimates from correlation functions evaluated at a limited number of values

Abstract

Techniques are provided for fine-tuning estimates of a delay value for a sampled signal. One aspect of the invention is to perform, for the sampled signal, coarse-grained calculations of the In Phase and Quadrature (I and Q) correlation integrals at a limited number of points, wherein the calculations are performed over a range of hypothesized delay values. A range of delay values of interest are then determined from the coarse-grained calculations of the I and Q correlation integrals. A subset of I and Q values based on the coarse granularity calculations of the I and Q correlation functions is used to perform a time-domain interpolation to obtain fine-grained values of the I and Q integrals in the range of the delay values of interest. Magnitude calculations are performed based on the fine-grained values of the I and Q integrals. Fine-tuned estimates of delay value are based on the magnitude calculations. Alternatively, fine-tuned estimates of delay value are based on the template-matching approach.

Claims41

Dependent claims

A method for determining one or more fine-tuned estimates of delay value associated with a received signal, the method comprising the computer-implemented steps of:

determining a range of delay values of interest associated with the received signal;
interpolating fine-grained values for I and Q correlation integrals by using a subset of coarse-grained calculations of I and Q correlation integrals;
and
determining the one or more fine-tuned estimates of delay value based on the fine-grained values of I and Q correlation integrals.

1 more element

A method for determining one or more fine-tuned estimates of delay value associated with a received signal, the method comprising the computer-implemented steps of:

determining an initial range of delay values of interest associated with the received signal;
performing, if not already performed, a coarse-grained calculation of I and Q correlation integrals over the initial range of delay values for a sampled data that is associated with the received signal;
calculating a magnitude of the coarse-grained calculations of I and Q correlation integrals over the hypothesized range of delay values;
and
selecting a delay value from the hypothesized range of delay values that correspond to a highest magnitude value that corresponds to the coarse-grained calculations of I and Q correlation integrals as an initial estimate of delay value;
selecting a range of delay values in the neighborhood of the initial estimate of delay value to be a range of delay values of interest;
generating a parametric template that represents I and Q correlation integrals associated with the received signal;
and
performing a linear regression on the range of delay values of interest to produce a delay error function that is based on the range of delay values of interest;
and
selecting from the range of delay values of interest one or more delay values that minimize the delay error function as the fine-tuned estimates of delay value.

8 more elements

A method for determining one or more fine-tuned estimates of carrier frequency value associated with a received signal, the method comprising the computer-implemented steps of:

determining a range of carrier frequency values of interest associated with the received signal;
interpolating fine-grained values for I and Q correlation integrals by using a subset of coarse-grained calculations of I and Q correlation integrals;
and
determining the one or more fine-tuned estimates of carrier frequency value based on the fine-grained values of I and Q correlation integrals.

1 more element

A method for determining one or more fine-tuned estimates of carrier frequency value associated with a received signal, the method comprising the computer-implemented steps of:

determining an initial range of carrier frequency values of interest associated with the received signal;
performing, if not already performed, a coarse-grained calculation of I and Q correlation integrals over the initial range of carrier frequency values for a sampled data that is associated with the received signal;
calculating a magnitude of the coarse-grained calculations of I and Q correlation integrals over the hypothesized range of carrier frequency values;
and
selecting a carrier frequency value from the hypothesized range of carrier frequency values that correspond to a highest magnitude value that corresponds to the coarse-grained calculations of I and Q correlation integrals as an initial estimate of carrier frequency value;
selecting a range of carrier frequency values in the neighborhood of the initial estimate of carrier frequency value to be a range of carrier frequency values of interest;
generating a parametric template that represents I and Q correlation integrals associated with the received signal;
performing a linear regression on the range of carrier frequency values of interest to produce a carrier frequency error function that is based on the range of carrier frequency values of interest;
and
selecting from the range of carrier frequency values of interest one or more carrier frequency values that minimize the carrier frequency error function as the fine-tuned estimates of carrier frequency value.

7 more elements

A method for determining one or more fine-tuned estimates of parameter value associated with a received signal, the method comprising the computer-implemented steps of:

determining an initial range of parameter values of interest associated with the received signal;
performing, if not already performed, a coarse-grained calculation of I and Q correlation integrals over the initial range of parameter values for a sampled data that is associated with the received signal;
calculating a magnitude of the coarse-grained calculations of I and Q correlation integrals over the hypothesized range of parameter values;
and
selecting a parameter value from the hypothesized range of parameter values that correspond to a highest magnitude value that corresponds to the coarse-grained calculations of I and Q correlation integrals as an initial estimate of parameter value;
selecting a range of parameter values in the neighborhood of the initial estimate of parameter value to be a range of parameter values of interest;
generating a parametric template that represents I and Q correlation integrals associated with the received signal;
and
performing a linear regression on the range of parameter values of interest to produce a parameter error function that is based on the range of parameter values of interest;
and
selecting from the range of parameter values of interest one or more parameter values that minimize the parameter error function as the fine-tuned estimates of parameter value.

8 more elements

Dependencies are inferred from the claim text.

Extracting fine-tuned estimates from correlation functions evaluated at a limited number of values

Life of this patent

Extracting fine-tuned estimates from correlation functions evaluated at a limited number of values

Life of this patent

Abstract

Claims41