Systems and Methods for Power Optimization in VLC Positioning

Abstract

Embodiments of systems and methods of power optimization in VLC positioning are disclosed. In one embodiment, a method of power optimization in visible light communication (VLC) positioning of a mobile device comprises receiving, by a transceiver, positioning assistance data of a venue, where the positioning assistance data includes identifiers and positions of light fixtures in the venue, decoding, by a VLC signal decoder, one or more light fixtures within a field of view of the mobile device to obtain corresponding light fixture identifiers, determining, by a controller, a motion of the mobile device with respect to the one or more light fixtures based on the light fixture identifiers and the positioning assistance data of the venue, and controlling, by the controller, the mobile device to operate in a reduced power mode based on the motion of the mobile device with respect to the one or more light fixtures.

We claim: 
     
         1 . A method of power optimization in visible light communication (VLC) positioning of a mobile device comprising:
 receiving, by a transceiver, positioning assistance data of a venue, wherein the positioning assistance data includes identifiers and positions of light fixtures in the venue;   decoding, by a VLC signal decoder, one or more light fixtures within a field of view of the mobile device to obtain corresponding light fixture identifiers;   determining, by a controller, a motion of the mobile device with respect to the one or more light fixtures based on the light fixture identifiers and the positioning assistance data of the venue; and   controlling, by the controller, the mobile device to operate in a reduced power mode based on the motion of the mobile device with respect to the one or more light fixtures.   
     
     
         2 . The method of  claim 1 , further comprising:
 in the reduced power mode,   monitoring angles of arrival of light from the one or more light fixtures in field of view of the mobile device; and   determining a position of the mobile device using decoded light fixture identifiers and the angles of arrival of light from the one or more light fixtures in field of view of the mobile device.   
     
     
         3 . The method of  claim 2 , wherein monitoring angles of arrival of light from the one or more light fixtures in field of view of-the mobile device comprises:
 for each light fixture in the field of view of the mobile device,
 measuring light pixels of the each light fixture for at least one image sensor frame; and 
 determining the field of view for the each light fixture based on the light pixels measured for the at least one image sensor frame. 
   
     
     
         4 . The method of  claim 1 , wherein controlling the mobile device to operate in a reduced power mode comprises:
 controlling an actuator of a camera of the mobile device to position one or more lenses of the camera in a fixed focal length during a period while the motion of the mobile device is above a first threshold.   
     
     
         5 . The method of  claim 1 , wherein controlling the mobile device to operate in a reduced power mode further comprises:
 controlling a video frontend engine of the mobile device to stop generating statistics data during a period while the motion of the mobile device is above a first threshold.   
     
     
         6 . The method of  claim 1 , wherein controlling the mobile device to operate in a reduced power mode further comprises:
 controlling a video front end engine of the mobile device to stop transferring statistics data to a memory during a period while the motion of the mobile device is above a first threshold.   
     
     
         7 . The method of  claim 1 , wherein controlling the mobile device to operate in a reduced power mode further comprises:
 controlling an image processing engine of the mobile device to stop processing data in support of auto focus, auto white balance, and auto exposure during a period while the motion of the mobile device is above a first threshold.   
     
     
         8 . The method of  claim 1 , wherein controlling the mobile device to operate in a reduced power mode further comprises:
 controlling the VLC signal decoder of the mobile device to intermittently decode incoming video frames during a period while the motion of the mobile device is above a first threshold.   
     
     
         9 . The method of  claim 1 , further comprising:
 detecting the motion of the mobile device with respect to the one or more light fixtures is below a second threshold; and   controlling the mobile device to operate in a normal power mode based on the motion of the mobile device with respect to the one or more light fixtures being below the second threshold.   
     
     
         10 . A mobile device, comprising:
 a camera configured to receive visible light communication signals;   a memory configured to store the visible light communication signals;   a transceiver configured to receive positioning assistance data of a venue, wherein the positioning assistance data includes identifiers and positions of light fixtures in the venue;   a VLC signal decoder configured to decode one or more light fixtures within a field of view of the mobile device to obtain corresponding light fixture identifiers;   a controller configured to:   determine a motion of the mobile device with respect to the one or more light fixtures based on the light fixture identifiers and the positioning assistance data of the venue; and   control the mobile device to operate in a reduced power mode based on the motion of the mobile device with respect to the one or more light fixtures.   
     
     
         11 . The mobile device of  claim 10 , wherein the controller is further configured to:
 in the reduced power mode,   monitor angles of arrival of light from the one or more light fixtures in field of view of the mobile device; and   determine a position of the mobile device using decoded light fixture identifiers and the angles of arrival of light from the one or more light fixtures in field of view of the mobile device.   
     
     
         12 . The mobile device of  claim 11 , wherein the controller is further configured to:
 for each light fixture in the field of view of the mobile device,
 measure light pixels of the each light fixture for at least one image sensor frame; and 
 determine the field of view for the each light fixture based on the light pixels measured for the at least one image sensor frame. 
   
     
     
         13 . The mobile device of  claim 10 , wherein the controller is further configured to:
 control an actuator of the camera of the mobile device to position one or more lenses of the camera in a fixed focal length during a period while the motion of the mobile device is above a first threshold.   
     
     
         14 . The mobile device of  claim 10 , wherein the controller is further configured to:
 control a video frontend engine of the mobile device to stop generating statistics data during a period while the motion of the mobile device is above a first threshold.   
     
     
         15 . The mobile device of  claim 10 , wherein the controller is further configured to:
 control a video front end engine of the mobile device to stop transferring statistics data to the memory during a period while the motion of the mobile device is above a first threshold.   
     
     
         16 . The mobile device of  claim 10 , wherein the controller is further configured to:
 control an image processing engine of the mobile device to stop processing data in support of auto focus, auto white balance, and auto exposure during a period while the motion of the mobile device is above a first threshold.   
     
     
         17 . The mobile device of  claim 10 , wherein the controller is further configured to:
 control a VLC signal decoder of the mobile device to intermittently decode incoming video frames during a period while the motion of the mobile device is above a first threshold.   
     
     
         18 . The mobile device of  claim 10 , wherein the controller is further configured to:
 detect the motion of the mobile device with respect to the one or more light fixtures is below a second threshold; and   control the mobile device to operate in a normal power mode based on the motion of the mobile device with respect to the one or more light fixtures being below the second threshold.   
     
     
         19 . A mobile device, comprising:
 means for receiving positioning assistance data of a venue, wherein the positioning assistance data includes identifiers and positions of light fixtures in the venue;   means for decoding one or more light fixtures within a field of view of the mobile device to obtain corresponding light fixture identifiers;   means for determining a motion of the mobile device with respect to the one or more light fixtures based on the light fixture identifiers and the positioning assistance data of the venue; and   means for controlling the mobile device to operate in a reduced power mode based on the motion of the mobile device with respect to the one or more light fixtures.   
     
     
         20 . The mobile device of  claim 19 , further comprising;
 in the reduced power mode,   means for monitoring angles of arrival of light from the one or more light fixtures in field of view of the mobile device; and   means for determining a position of the mobile device using decoded light fixture identifiers and the angles of arrival of light from the one or more light fixtures in field of view of the mobile device.   
     
     
         21 . The mobile device of  claim 20 , wherein monitoring angles of arrival of light from the one or more fight fixtures in field of view of the mobile device comprises:
 for each light fixture in the field of view of the mobile device,
 means for measuring light pixels of the each light fixture for at least one image sensor frame; and 
 means for determining the field of view for the each light fixture based on the light pixels measured for the at least one image sensor frame. 
   
     
     
         22 . The mobile device of  claim 19 , wherein the means for controlling the mobile device to operate in a reduced power mode comprises:
 means for controlling an actuator of a camera of the mobile device to position one or more lenses of the camera in a fixed focal length during a period while the motion of the mobile device is above a first threshold.   
     
     
         23 . The mobile device of  claim 19 , wherein the means for controlling the mobile device to operate in a reduced power mode further comprises:
 means for controlling a video frontend engine of the mobile device to stop generating statistics data during a period while the motion of the mobile device is above a first threshold.   
     
     
         24 . The mobile device of  claim 19 , wherein the means for controlling the mobile device to operate in a reduced power mode further comprises:
 means for controlling a video front end engine of the mobile device to stop transferring statistics data to a memory during a period while the motion of the mobile device is above a first threshold.   
     
     
         25 . The mobile device of  claim 19 , wherein the means for controlling the mobile device to operate in a reduced power mode further comprises:
 means for controlling an image processing engine of the mobile device to stop processing data in support of auto focus, auto white balance, and auto exposure during a period while the motion of the mobile device is above a first threshold.   
     
     
         26 . The mobile device of  claim 19 , wherein the means for controlling the mobile device to operate in a reduced power mode further comprises:
 means for controlling a VLC signal decoder of the mobile device to intermittently decode incoming video frames during a period while the motion of the mobile device is above a first threshold.   
     
     
         27 . The mobile device of  claim 19 , further comprising:
 means for detecting the motion of the mobile device with respect to the one or more light fixtures is below a second threshold; and   means for controlling the mobile device to operate in a normal power mode based on the motion of the mobile device with respect to the one or more light fixtures being below the second threshold.   
     
     
         28 . A non-transitory medium storing instructions for execution by one or more processors of a mobile device, the instructions comprising:
 instructions for receiving, by a transceiver, positioning assistance data of venue, wherein the positioning assistance data includes identifiers and positions of light fixtures in the venue;   instructions for decoding, by a VLC signal decoder, one or more light fixtures within a field view of the mobile device to obtain corresponding light fixture identifiers;   instructions for determining, by a controller, a motion of the mobile device with respect to the one or more light fixtures based on the light fixture identifiers and the positioning assistance data of the venue; and   instructions for controlling, by the controller, the mobile device to operate in a reduced power mode based on the motion of the mobile device with respect to the one or more light fixtures.   
     
     
         29 . The non-transitory medium of  claim 28 , further comprising:
 in the reduced power mode,   instructions for monitoring angles of arrival of light from the one or more light fixtures in field of view of the mobile device; and   instructions for determining a position of the mobile device using decoded light fixture identifiers and the angles of arrival of light from the one or more light fixtures in field of view of the mobile device.   
     
     
         30 . The non-transitory medium of  claim 29 , wherein the instructions for monitoring angles of arrival of light from the one or more light fixtures in field of view of the mobile device comprises:
 for each light fixture in the field of the mobile device,
 instructions for measuring light pixels of the each light fixture for at least one image sensor frame; and 
 instructions for determining the field of view for the each light fixture based on the light pixels measured for the at least one image sensor frame.