System and method for estimating the position and orientation of a mobile communications device in a beacon-based positioning system

Abstract

An example of a system including a plurality of lighting devices, each lighting device including a light source, a modulator and a processor. Each processor is configured to control the respective light source to emit light for general illumination and control the respective modulator to modulate the intensity of the emitted light to broadcast a respective signal modulated on the emitted light within a respective range of frequencies. A first lighting device and a second lighting device modulate emitted light within the same range of frequencies when the first lighting device is set at a distance from the second lighting device such that modulated light emitted by the first lighting device appears in a first portion of an image sensor of a mobile device and modulated light emitted by the second lighting device appears in a second portion of the image sensor separate from the first portion.

What is claimed is: 
     
         1 . A system, comprising a plurality of lighting devices installed within a space, each lighting device comprising:
 a light source;   a modulator coupled to the light source; and   a processor coupled to the modulator and configured to:
 control the respective light source to emit visible light for general illumination within the space; and 
 control the respective modulator to modulate the intensity of visible light emitted by the respective light source based on a respective signal, the intensity of visible light modulated within a respective range of frequencies; 
   wherein:
 a first lighting device emits modulated visible light within a first range of frequencies; 
 a second lighting device also emits modulated visible light within the first range of frequencies; and 
 the first lighting device is set relative to the second lighting device such that the modulated visible light emitted by the first lighting device appears on a first region of an image sensor of a mobile device and the modulated visible light emitted by the second lighting device appears on a second region of the image sensor separate and distinct from the second region of the image sensor. 
   
     
     
         2 . The system of  claim 1 , wherein the modulated visible light emitted by the first lighting device shares at least one frequency within the first range with the modulated visible light emitted by the second lighting device. 
     
     
         3 . The system of  claim 2 , wherein the modulated visible light emitted by the first lighting device shares the same frequencies as the modulated visible light emitted by the second lighting device. 
     
     
         4 . The system of  claim 1 , further comprising a plurality of additional lighting devices installed within the space, each additional lighting device comprising:
 a light source;   a modulator coupled to the light source; and   a processor coupled to the modulator and configured to:
 control the respective light source to emit visible light for general illumination within the space; and 
 control the respective modulator to modulate the intensity of visible light emitted by the respective light source based on a respective additional signal, the intensity of visible light modulated within a respective additional range of frequencies; 
   wherein:
 a first additional lighting device emits modulated visible light within a first additional range of frequencies; 
 the first additional lighting device is set relative to the first lighting device such that modulated visible light emitted by the first additional lighting device and the modulated visible light emitted by the first lighting device appear on the first region of the image sensor; and 
 the first additional range of frequencies of the first additional lighting device is different from the first range of frequencies. 
   
     
     
         5 . The system of  claim 4 , wherein:
 a second additional lighting device emits modulated visible light within a second additional range of frequencies;   the second additional lighting device is set relative to the second lighting device such that modulated visible light emitted by the second additional lighting device and the modulated visible light emitted by the second lighting device appear on the second region of the image sensor; and   the second additional range of frequencies of the second additional lighting device is different from the first range of frequencies.   
     
     
         6 . The system of  claim 5 , wherein the first additional range of frequencies of the first additional lighting device is the same as the second additional range of frequencies of the second additional lighting device. 
     
     
         7 . The system of  claim 6 , wherein the modulated visible light emitted by the first additional lighting device shares at least one frequency within the first additional range with the modulated visible light emitted by the second additional lighting device. 
     
     
         8 . The system of  claim 7 , wherein the modulated visible light emitted by the first additional lighting device shares the same frequencies as the modulated visible light emitted by the second additional lighting device. 
     
     
         9 . A method, comprising steps to:
 emit, by an artificial light source of a first lighting device, visible artificial light for general illumination within a space;   modulate, by a modulator of the first lighting device, the intensity of visible artificial light emitted by the light source of the first lighting device to broadcast a first signal modulated on the emitted visible artificial light of the first lighting device, the intensity of visible artificial light emitted by the light source of the first lighting device modulated within a first range of frequencies;   emit, by an artificial light source of a second lighting device, visible artificial light for general illumination within the space; and   modulate, by a modulator of the second lighting device, the intensity of visible artificial light emitted by the light source of the second lighting device to broadcast a second signal modulated on the emitted visible artificial light of the second lighting device, the intensity of visible artificial light emitted by the light source of the second lighting device also modulated within the first range of frequencies;   wherein the first lighting device is set relative to the second lighting device such that modulated visible artificial light emitted by the first lighting device appears on a first region of an image sensor of a mobile device and modulated visible artificial light emitted by the second lighting device appears on a second region of the image sensor separate and distinct from the second region of the image sensor.   
     
     
         10 . The method of  claim 9 , wherein the modulated visible artificial light emitted by the first lighting device shares at least one frequency within the first range with the modulated visible artificial light emitted by the second lighting device. 
     
     
         11 . The method of  claim 10 , wherein the modulated visible artificial light emitted by the first lighting device shares the same frequencies as the modulated visible light emitted by the second lighting device. 
     
     
         12 . The method of  claim 9 , further comprising steps to:
 emit, by an artificial light source of a third lighting device, visible artificial light for general illumination within the space;   modulate, by a modulator of the third lighting device, the intensity of visible artificial light emitted by the light source of the third lighting device to broadcast a third signal modulated on the emitted visible artificial light of the third lighting device, the intensity of visible artificial light emitted by the light source of the third lighting device modulated within a second range of frequencies;   wherein:
 the third lighting device is set relative to the first lighting device such that modulated visible artificial light emitted by the third lighting device and the modulated visible artificial light emitted by the first lighting device appear on the first region of the image sensor; and 
 the second range of frequencies is different from the first range of frequencies. 
   
     
     
         13 . The method of  claim 12 , further comprising steps to:
 emit, by an artificial light source of a fourth lighting device, visible artificial light for general illumination within the space; and   modulate, by a modulator of the fourth lighting device, the intensity of visible artificial light emitted by the light source of the fourth lighting device to broadcast a fourth signal modulated on the emitted visible artificial light of the fourth lighting device, the intensity of visible artificial light emitted by the light source of the fourth lighting device modulated within a third range of frequencies;   wherein:
 the fourth lighting device is set relative to the second lighting device such that modulated visible artificial light emitted by the fourth lighting device and the modulated visible artificial light emitted by the second lighting device appear on the second region of the image sensor; and 
 the third range of frequencies is different from the first range of frequencies. 
   
     
     
         14 . The method of  claim 13 , wherein the second range of frequencies is the same as the third range of frequencies. 
     
     
         15 . The method of  claim 14 , wherein the modulated visible light emitted by the third lighting device shares at least one frequency within the second range with the modulated visible light emitted by the fourth lighting device. 
     
     
         16 . The method of  claim 15 , wherein the modulated visible light emitted by the third lighting device shares the same frequencies as the modulated visible light emitted by the fourth lighting device. 
     
     
         17 . A mobile device, comprising:
 an image sensor;   a processor coupled to the image sensor;   a memory; and   software in the memory to be run by the processor, wherein running of the software by the processor configures the mobile device to implement functions, including functions to:
 operate the image sensor to capture one or more images including a first modulated visible light signal transmitted from a first visible light source and a second modulated visible light signal transmitted from a second visible light source, wherein:
 the first modulated visible light signal is modulated within a first range of frequencies; 
 the first modulated visible light signal appears on a first region of the image sensor; 
 the second modulated visible light signal is also modulated within first range of frequencies; and 
 the second modulated visible light signal appears on a second region of the image sensor separate and distinct from the first region of the image sensor; 
 
 process the one or more captured images to separate the first and second regions of the image sensor; 
 demodulate, based on the first range of frequencies, the first modulated visible light signal appearing on the first region of the image sensor to obtain a first data carried in the first modulated visible light signal; and 
 demodulate, based on the first range of frequencies, the second modulated visible light signal appearing on the second region of the image sensor to obtain second data carried in the second modulated visible light signal. 
   
     
     
         18 . The mobile device of  claim 17 , wherein the first modulated visible light signal includes at least one frequency within the first range in common with the second modulated visible light signal. 
     
     
         19 . The mobile device of  claim 18 , wherein the first modulated visible light signal includes the same frequencies as the second modulated visible light signal. 
     
     
         20 . The mobile device of  claim 17 , wherein:
 the one or more captured images further include a third modulated visible light signal transmitted from a third visible light source, the third modulated visible light signal being modulated within a second range of frequencies and the third modulated visible light signal appearing on the first region of the image sensor; and   the function to demodulate the first modulated visible light signal further includes a function to demodulate, based on the second range of frequencies, the third modulated visible light signal to obtain third data carried in the third modulated visible light signal.