US 10,477,353 B2 · System and method of time of flight detection

Abstract

A position-determining apparatus, such as a GPS receiver, determines the position of the mobile device based on the time of flight of a transmitted probe signal using a method in which sections of the received signal is classified into two or more categories and accumulated according to categories before being used to compute the correlations familiar in the context of a matched filter. Using the method of the present invention to compute the correlations, and optionally applying additional time-saving techniques described herein, a position determination is achieved using arithmetic operations that are significantly reduced from that required in prior art methods to compute the correlations. The reduced number of arithmetic operations can reduce significantly the power consumption required of a device carrying out a method of the present invention, and thereby realizing a significant advantage.

Claims37

Dependent claims

A method for determining a distance from a source based on a signal received at a receiver, the received signal being a known probe signal transmitted from the source, the method comprising:

retrieving accumulated sums of categorized sections of the probe signal, wherein (i) each categorized section being of predetermined duration and which is categorized into one of a predetermined number of categories based on signal transitions represented by signal values in the categorized section;
and (ii) each accumulated sum being formed by summing all signal values of categorized sections of the probe signal that are categorized to the same one of the categories;
for each of a plurality of offsets relative to the probe signal:
dividing the received signal, after being delayed by the offset, into sections, each section being of the predetermined duration;
and
computing a correlation between the received signal delayed by the offset and the probe signal, using signal values of the sections of the delayed received signal and the accumulated sums.

3 more elements

Dependencies are inferred from the claim text.

System and method of time of flight detection

Life of this patent

System and method of time of flight detection

Life of this patent

Abstract

Claims37