System and method for estimating signal time of arrival

A method for estimating a time delay, the method comprising the steps of:

• a. estimating a channel spectrum from a received signal and a known reference signal;
• b. formulating a unique data matrix using the estimated channel spectrum;
• and
• c. determining a time delay estimate using the data matrix, wherein step (b) comprises the step of constructing a signal space using the estimated channel spectrum and one slot so that the signal space includes delay and multipath information.

A method for estimating a time delay, the method comprising the steps of:

• a. estimating a channel spectrum from a received signal and a known reference signal;
• b. formulating a unique data matrix using the estimated channel spectrum;
• and
• c. determining a time delay estimate using the data matrix, wherein step (c) comprises the steps of
• a. performing singular value decomposition on the data matrix;
• b. detecting automatically, based on the singular value decomposition results, the number of physical paths;
• c. determining a noise space using the number of physical paths;
• d. determining a projection polynomial using the noise space;
• e. determining at least one root pair by solving the projection polynomial;
• f. mapping the roots to determine a rough time delay estimate;
• and
• g. estimating the time delay by removing bias in the rough time delay estimate.

A method for estimating a time delay, the method comprising the steps of:

• a. estimating a channel spectrum from a received signal and a known reference signal;
• b. formulating a unique data matrix using the estimated channel spectrum;
• and
• c. determining a time delay estimate using the data matrix, wherein the known reference signal in step (a) is a shortened burst or sync word in norm burst in an IS-136 system.

A method for estimating a time of arrival, the method comprising the steps of:

• a. matched filtering an input signal to produce a matched filtered signal;
• b. buffering the matched filtered signal and adding global positioning system time stamps to produce a buffered signal;
• c. compensating for the carrier offset in the buffered signal to produce a received signal;
• d. determining the start of a shortened burst signal in the received signal using a framer;
• e. at the start of the shortened burst, determining the inter-symbol delay by framing the shortened burst;
• f. at the start of the shortened burst, estimating a channel response using the received signal and a known reference signal;
• g. formulating a data matrix using the estimated channel spectrum;
• h. determining an intra-symbol delay estimate using the data matrix;
• and
• j. determining a time of arrival by adding the inter-symbol delay and the intra-symbol delay.

A system for estimating a time delay, the system comprising:

• a. a channel spectrum estimator for estimating a channel spectrum from a received signal and a known reference signal;
• b. means for extracting a virtual array structure from the estimated channel spectrum;
• and
• c. means for determining the time delay using the virtual array
• structure, wherein the extracting means comprises means for formulating a data matrix representing a signal space, the formulating means using the estimated channel spectrum and one slot so that the data matrix representing the signal space includes delay and multipath information.

A system for estimating a time delay, the system comprising:

• a. a channel spectrum estimator for estimating a channel spectrum from a received signal and a known reference signal;
• b. means for extracting a virtual array structure from the estimated channel spectrum;
• and
• c. means for determining the time delay using the virtual array structure, wherein the determining means comprises:
• a. means for performing singular value decomposition on the data matrix;
• b. means for detecting automatically, based on the singular value decomposition results, the number of physical paths;
• c. means for determining a noise space using the number of physical paths;
• d. means for determining a projection polynomial using the noise space;
• e. means for determining at least one root pair by solving the projection polynomial;
• f. means for mapping the roots to determine a rough intra-symbol delay estimate;
• and
• g. means for estimating the intra-symbol delay by removing bias in the rough time delay estimate.