TRACKING DETERMINATION BASED ON INTENSITY ANGULAR GRADIENT OF A WAVE
Handheld device, base station, computer readable medium and method for detecting a position of a handheld device. The method includes measuring intensities of at least one beam emitted by a base station; calculating relative intensities based on the measured intensities; and determining the position of the handheld device based on the measured intensities and the calculated relative intensities.
1 . A method for detecting a position of a handheld device, the method comprising:
measuring intensities of at least one beam emitted by a base station;
calculating relative intensities based on the measured intensities; and
determining the position of the handheld device based on the measured intensities and the calculated relative intensities.
2 . The method of claim 1 , further comprising:
providing that at least one beam have a predetermined angular gradient intensity distribution.
3 . The method of claim 1 , further comprising:
receiving intensities from plural base stations; and
independently controlling with the handheld device each base station of the plural base stations.
4 . The method of claim 1 , further comprising:
measuring the intensities with plural handheld devices; and
controlling the base station with each handheld device of the plural handheld devices.
5 . The method of claim 1 , further comprising:
determining a first direction from the base station to the handheld device based on the calculated relative intensities, the first direction being defined in a frame of reference associated with the base station; and
determining a second direction from the handheld device to the base station based on the calculated relative intensities, the second direction being defined in a frame of reference associated with the handheld device, wherein the first direction is defined by two angles and the second direction is defined by other two angles.
6 . The method of claim 1 , wherein the at least one beam is not modulated to transmit data.
7 . The method of claim 2 , wherein the step of determining the position further comprises:
calculating a distance from the handheld device to the base station based on the first direction, the second direction, and a distance function; and
determining a linear position of the handheld device as the distance of the handheld device from the base station along the first direction.
8 . The method of claim 4 , further comprising:
storing a lookup table that maps the measured intensities to the two angles and/or to the two other angles defining the first and second directions, and/or
storing a lookup table mapping the two angles defining the first direction, the other two angles defining the second direction and measured intensities to the distance between the handheld device and the base station.
9 . The method of claim 1 , further comprising:
measuring three intensities of the at least one beam with three different receivers provided on the handheld device.
10 . The method of claim 1 , further comprising:
emitting three different beams from the base station.
11 . The method of claim 10 , further comprising:
modulating differently the three different beams.
12 . The method of claim 5 , further comprising:
determining a two angles angular position of the handheld device based on the determined first direction and the determined second direction.
13 . The method of claim 12 , further comprising:
estimating a gravity vector; and
computing a third angle of the angular position of the handheld device relative to the base station based on the gravity vector.
14 . The method of claim 1 , further comprising:
associating a cursor on a screen with the handheld device position.
15 . A handheld device for detecting a position relative to a base station with which the handheld device communicates, the handheld device comprising:
a first receiver configured to measure intensities of beams emitted by a base station; and
a processor connected to the first receiver and configured to,
calculate relative intensities based on the measured intensities, and
determine the position of the handheld device based on the measured intensities and the calculated relative intensities.
16 . The handheld device of claim 15 , wherein the processor is further configured to determine a first direction from the base station to the handheld device based on the calculated relative intensities, the first direction being defined in a frame of reference associated with the base station.
17 . The handheld device of claim 16 , further comprising:
second and third receivers configured to measure the intensities,
wherein the processor is further configured to determine a second direction from the handheld device to the base station based on the calculated relative intensities, the second direction being defined in a frame of reference associated with the handheld device, wherein the first direction is defined by two angles and the second direction is defined by other two angles.
18 . The handheld device of claim 17 , further comprising:
a storing device configured to store a lookup table that maps the measured intensities to the two angles and/or to the two other angles defining the first and second directions.
19 . The handheld device of claim 17 , wherein the processor is further configured to:
calculate a distance from the handheld device to the base station based on the first direction, the second direction, and a distance function; and
determine a linear position of the handheld device as the distance of the handheld device from the base station along the first direction.
20 . The handheld device of claim 19 , further comprising:
a storing device configured to store a lookup table mapping angles defining the first direction, angles defining the second direction and measured intensities to the distance between the handheld device and the base station.
21 . The handheld device of claim 17 , wherein the processor is further configured to determine a two angles angular position of the handheld device based on the determined first direction and the determined second direction.
22 . The handheld device of claim 21 , further comprising:
an accelerometer configured to estimate a gravity vector,
wherein the processor is further configured to compute a third angle of the angular position of the handheld device relative to the base station based on the gravity vector.
23 . A base station configured to communicate with a handheld device, the base station comprising:
at least one emitter configured to emit a beam of an electromagnetic wave such that an intensity of the beam has a desired angular distribution in space; and
a processor configured to control an emitting time of the at least one emitter, wherein an amplitude the beam follows a same pattern in time at a given location.
24 . The base station of claim 23 , wherein the beam is not modulated.
25 . The base station of claim 23 , wherein the processor is further configured to receive data from the handheld device, the data being indicative of a first direction from the base station to the handheld device and a second direction from the handheld device to the base station.
26 . The base station of claim 23 , wherein the processor is further configured to compute a distance from the handheld device to the base station based on the received data from the handheld device.
27 . The base station of claim 23 , wherein the processor is further configured to compute a linear position of the handheld device and an angular orientation of the handheld device based on the received data from the handheld device.
28 . The base station of claim 23 , further comprising:
second and third sensors configured to be displaced with the at least one sensor on a spherical, equilateral triangle.
29 . A system comprising:
a handheld device having a first receiver;
a base station having plural emitters and configured to communicate with the handheld device; and
a processor configured to communicate with the first receiver, wherein
the first receiver is configured to measure intensities of beams emitted by the emitters,
the processor is configured to calculate relative intensities based on the measured intensities, and
the processor is configured to determine the position of the handheld device based on the measured intensities and the calculated relative intensities.
30 . The system of claim 29 , wherein each of the plural emitters is configured to emit a corresponding beam having a predetermined angular gradient intensity distribution.
31 . The system of claim 29 , further comprising:
plural base stations configured to communicate with the handheld device,
wherein the handheld device is configured to independently control each base station of the plural base stations.
32 . The system of claim 29 , further comprising:
plural handheld devices configured to communicate with the base station,
wherein each handheld device of the plural handheld devices is configured to independently control the base station.
33 . The system of claim 29 , wherein the processor is distributed only at the base station or only at the handheld device.
34 . The system of claim 29 , wherein the processor is configured to,
determine a first direction from the base station to the handheld device based on the calculated relative intensities, the first direction being defined in a frame of reference associated with the base station; and
determine a second direction from the handheld device to the base station based on the calculated relative intensities, the second direction being defined in a frame of reference associated with the handheld device, wherein the first direction is defined by two angles and the second direction is defined by other two angles.
35 . The system of claim 34 , wherein the processor is further configured to:
calculate a distance from the handheld device to the base station based on the first direction, the second direction, and a distance function; and
determine a linear position of the handheld device as the distance of the handheld device from the base station along the first direction.
36 . The system of claim 34 , wherein the processor is further configured to:
determine a two angles angular position of the handheld device based on the determined first direction and the determined second direction.
37 . The system of claim 36 , wherein the processor is further configured to:
estimate a gravity vector; and
compute a third angle of the angular position of the handheld device relative to the base station based on the gravity vector.
38 . A computer readable medium including computer executable instructions, wherein the instructions, when executed, implement a method for detecting a position of a handheld device, the method comprising:
providing a system comprising distinct software modules, wherein the distinct software modules comprise a relative intensity calculation module, a linear position calculation module and an angular position calculation module;
measuring intensities of at least one beam emitted by a base station;
calculating, based on the relative intensity calculation module, relative intensities based on the measured intensities; and
determining, based on the linear position calculation module, the position of the handheld device based on the measured intensities and the calculated relative intensities.
39 . The medium of claim 36 , further comprising:
determining a first direction from the base station to the handheld device based on the calculated relative intensities, the first direction being defined in a frame of reference associated with the base station; and
determining a second direction from the handheld device to the base station based on the calculated relative intensities, the second direction being defined in a frame of reference associated with the handheld device, wherein the first direction is defined by two angles and the second direction is defined by other two angles.
40 . The medium of claim 39 , wherein the at least one beam is not modulated to transmit data.
41 . The medium of claim 39 , wherein the step of determining the position further comprises:
calculating a distance from the handheld device to the base station based on the first direction, the second direction, and a distance function; and
determining a linear position of the handheld device as the distance of the handheld device from the base station along the first direction.
42 . The medium of claim 41 , further comprising:
storing a lookup table that maps the measured intensities to the two angles and/or to the two other angles defining the first and second directions, and/or
storing a lookup table mapping the two angles defining the first direction, the other two angles defining the second direction and measured intensities to the distance between the handheld device and the base station.
43 . The medium of claim 38 , further comprising:
measuring three intensities of the at least one beam with three different receivers provided on the handheld device.
44 . The medium of claim 38 , further comprising:
emitting three different beams from the base station.
45 . The medium of claim 43 , further comprising:
modulating differently the three different beams.
46 . The medium of claim 39 , further comprising:
determining a two angles angular position of the handheld device based on the determined first direction and the determined second direction.
47 . The medium of claim 46 , further comprising:
estimating a gravity vector; and
computing a third angle of the angular position of the handheld device relative to the base station based on the gravity vector.