Systems and methods for determining position using light sources

A positioning system comprising:

• a positioning transmitter system comprising:
• at least four light sources each configured to emit light having a wavelength in the visible light spectrum;
• and
• a master anchor configured to modulate said at least four light sources such that each of said at least four light sources emits modulated light signals at a modulation frequency;
• and
• a positioning receiver system configured to be coupled to said object, said positioning receiver system comprising:
• a lens configured to focus each of said at least four modulated light signals onto a respective one of a plurality of optical sensors;
• an envelope detector configured to receive at least four sensor output signals from said optical sensors corresponding to said at least four modulated light signals and provide at least four output signals corresponding to said modulation frequency for each of said at least four modulated light signals;
• and
• positioning detection circuitry, said positioning detection circuitry configured to:
• receive calibration data associated with each of said at least four modulated light sources;
• determine at least four phase difference of arrival (PDOA) pairs based on said at least four output signals from said envelope detector;
• determine at least four phase corrected PDOA pairs based, at least in part, on said calibration data and said at least four PDOA pairs;
• determine at least four linear distance differences based on said at least four phase corrected PDOA pairs;
• and
• determine said coordinate of said object based on said at least four linear distance differences and said calibration data.

An apparatus for determining a coordinate of an object based on at least four modulated light signals emitted from at least four light sources configured to emit light having a wavelength in the visible light spectrum, said modulated light signals each having a modulation frequency, said apparatus comprising:

• a positioning receiver system configured to be coupled to said object, said positioning receiver system comprising:
• a lens configured to focus each of said at least four modulated light signals onto a respective one of a plurality of optical sensors;
• an envelope detector configured to receive at least four sensor output signals from said optical sensors corresponding to said at least four modulated light signals and provide at least four output signals corresponding to said modulation frequency for each of said at least four modulated light signals;
• and
• positioning detection circuitry, said positioning detection circuitry configured to:
• receive calibration data associated with each of said at least four light sources;
• determine at least four phase difference of arrival (PDOA) pairs based on said at least four output signals from said envelope detector;
• determine at least four phase corrected PDOA pairs based, at least in part, on said calibration data and said at least four PDOA pairs;
• determine at least four linear distance differences based on said at least four phase corrected PDOA pairs;
• and
• determine said coordinate of said object based on said at least four linear distance differences and said calibration data.