 |
Claims  |
|
|
What is claimed is:
1. A location positioning system for use in a shielded environment, said
system comprising:
a GPS receiver for receiving GPS signals having navigational data encoded
therein;
a clock recovery unit that constructs a clock signal using said
navigational data, wherein said clock signal accurately represents a local
time;
a computer processing unit for receiving said clock signal and said
navigational data; and
at least four pseudosatellites positioned within the shielded environment,
one of said at least four pseudosatellites being non-coplanar relative to
the others, wherein said computer processing unit generates a respective
GPS-type signal corresponding to each of said at least four
pseudosatellites, said respective GPS-type signal containing new orbital
parameters for each corresponding pseudosatellite.
2. The location positioning system according to claim 1 wherein said
GPS-type signals are transmitted into the shielded environment to be
received by a receiver device located therein, said receiver device
capable of transmitting a location signal.
3. The location positioning system according to claim 2 further including
computer means and a location receiver associated therewith, said location
receiver being positioned within said shielded environment to receive said
location signal from said receiver device so that a precise position of
said location receiver may be determined by said computer means by
processing said location signal.
4. The location positioning system according to claim 2 wherein said
location device includes a cellular phone.
5. The location positioning system according to claim 2 wherein said
location device includes a badge capable of being attached to a person
moving within the shielded environment.
6. A personnel location and tracking system for use in a work-place
environment, said system comprising:
a GPS receiver for receiving GPS signals and transmitting navigational
data;
a clock recovery unit for receiving said navigational data and
reconstructing an accurate clock signal;
a computer processing unit for receiving said accurate clock signal and
said navigational data;
at least four pseudosatellites positioned within the work-place
environment, one of said at least four pseudosatellites being non-coplanar
relative to the others, wherein said computer processing unit generates a
respective GPS-type signal corresponding to each of said at least four
pseudosatellites, said respective GPS-type signal containing new orbital
parameters for each corresponding pseudosatellite;
a receiver device carried by an individual moving within the work-place
environment, said receiver device capable of transmitting a location
signal, said GPS-type signals being transmitted into the work-place
environment to be received by said receiver device; and
computer means having a location receiver associated therewith, said
location receiver being positioned within the work-place environment to
receive said location signal from said receiver device so that a precise
position of the individual carrying said location receiver may be
determined by said computer means by processing said location signal.
7. An inventory location and tracking system for use in a warehouse storage
facility, said system comprising:
a GPS receiver for receiving GPS signals and transmitting navigational
data;
a clock recovery unit for receiving said navigational data and
reconstructing an accurate clock signal;
a computer processing unit for receiving said accurate clock signal and
said navigational data;
at least four pseudosatellites positioned within the warehouse storage
facility, one of said at least four pseudosatellites being non-coplanar
relative to the others, wherein said computer processing unit generates a
respective GPS-type signal corresponding to each of said at least four
pseudosatellites, said respective GPS-type signal containing new orbital
parameters for each corresponding pseudosatellite;
a receiver device attached to a respective item of inventory in warehouse
storage facility, said receiver device capable of transmitting a location
signal, said GPS-type signals being transmitted into the warehouse storage
facility to be received by said receiver device; and
computer means having a location receiver associated therewith, said
location receiver being positioned within the warehouse storage facility
to receive said location signal from said receiver device so that a
precise position of the respective item of inventory having said location
receiver may be determined by said computer means by processing said
location signal.
8. A personal communications and location system for use in an indoor
environment, said system comprising:
a GPS receiver for receiving GPS signals and transmitting navigational
data;
a clock recovery unit for receiving said navigational data and
reconstructing an accurate clock signal;
a computer processing unit for receiving said accurate clock signal and
said navigational data;
at least four pseudosatellites positioned within the indoor environment,
one of said at least four pseudosatellites being non-coplanar relative to
the others, wherein said computer processing unit generates a respective
GPS-type signal corresponding to each of said at least four
pseudosatellites, said respective GPS-type signal containing new orbital
parameters for each corresponding pseudosatellite;
a receiver device in combination with a cellular phone carried by an
individual moving within the indoor environment, said receiver device
capable of transmitting a location signal, said GPS-type signals being
transmitted into the indoor environment to be received by said receiver
device; and
computer means having a location receiver associated therewith, said
location receiver being positioned within the indoor environment to
receive said location signal from said receiver device so that a precise
position of the individual carrying said location receiver may be
determined by said computer means by processing said location signal, said
cellular phone providing a personal communication link with an operator of
said computer means.
9. A combined positioning system for locating an object moving between a
shielded environment and unobstructed open space, said system comprising:
plurality of global positioning satellites in orbit around the Earth, each
of said global positioning satellites broadcasting a standard GPS signal;
a first GPS receiver for receiving the standard GPS signals and
transmitting navigational data;
a clock recovery unit for receiving said navigational data and
reconstructing an accurate clock signal;
a computer processing unit for receiving said accurate clock signal and
said navigational data;
at least four pseudosatellites positioned within the shielded environment,
one of said at least four pseudosatellites being non-coplanar relative to
the others, wherein said computer processing unit generates a respective
GPS-type signal corresponding to each of said at least four
pseudosatellites, said respective GPS-type signal containing new orbital
parameters for each corresponding pseudosatellite;
a receiver device attached to the moving object, said receiver device
capable of transmitting a location signal, said GPS-type signals being
transmitted into the shielded environment to be received by said receiver
device;
computer means having a location receiver associated therewith, said
location receiver being positioned within the shielded environment to
receive said location signal from said receiver device so that a precise
indoor position of the moving object having said location receiver may be
determined by said computer means by processing said location signal when
the object is within the shielded environment; and
a second GPS receiver attached to the moving object, said second GPS
receiver for receiving the standard GPS signals when the object is in the
unobstructed open space so that a precise outdoor position of the moving
object having said second GPS receiver may be obtained.
10. An interior positioning system comprising:
a GPS receiver for receiving GPS signals and transmitting NAVDAT data;
a clock recovery unit for receiving NAVDAT data and reconstructing an
accurate clock signal;
a computer for receiving the accurate clock signal and the NAVDAT data,
said computer capable of calculating pseudosatellite data for at least
four pseudosatellites, and the pseudosatellites capable of transmitting
pseudosatellite data signals from the pseudosatellite data, wherein the
pseudosatellite data signals are used for determining interior position.
11. The interior positioning system of claim 10 further comprising a second
GPS receiver for receiving the pseudosatellite data signals, said second
GPS receiver being capable of using the pseudosatellite data signals to
determine the interior position of the second GPS receiver.
12. The interior positioning system of claim 11 further comprising means
for communication between the second GPS receiver and the computer.
13. The interior positioning system of claim 12 wherein said means for
communication is a duplex system capable of relaying the position of the
second GPS receiver to the computer and capable of relaying information
from the computer to the second GPS receiver.
14. A method for providing an interior positioning system comprising the
steps:
receiving GPS signals;
reconstructing an accurate clock signal from the GPS signals;
calculating orbital parameters for at least four pseudosatellites; and
transmitting pseudosatellite data signals using the reconstructed clock
signal and orbital parameters for at least four pseudosatellites.
15. The method for providing an interior positioning system of claim 14
further comprising the steps:
generating NAVDAT information from the received GPS signals;
using the NAVDAT information for calculating the orbital parameters for the
pseudosatellites; and
adding offsets to the NAVDAT information when calculating the orbital
parameters.
16. The method for providing an interior positioning system of claim 6
further comprising the step of delaying the reconstructed clock signal to
account for different propagation time to each of the pseudosatellites. |
|
 |
|
 |
Claims |
|
|
|
Description |
|
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to positioning or location systems and,
in particular, to such a system as utilized to locate objects within an
interior space or shielded environment. More specifically, but without
restriction to the particular embodiments hereinafter described in
accordance with the current best mode of practice, this invention relates
to a location positioning system for use in a shielded environment that
utilizes GPS-type signals.
2. Discussion of the Related Art
The art of proximity detection and position location has been contributed
to by a number of proposed devices and systems. These include, for
example, the device discussed in U.S. Pat. No. 5,311,185 to Hochstein et
al. which is directed to a proximity detection device relying on a
transponder that periodically transmits status signals. Transceivers are
fixed at locations about a structure for receiving and transmitting
signals. U.S. Pat. No. 5,363,425 to Mufti et al. incorporates an
identification badge having a radio frequency (RF) transmitter. Radio
frequency (RF) receivers are located in telephones in various rooms of a
structure. The location of the identification tag is determined to be the
room with the nearest phone. Anders et al. in U.S. Pat. No. 4,656,463,
propose a passive transceiver tag which is sensed by an active
transceiver. This proximity control system forms the basis for a location,
identification, and measurement of movement of inventory system, commonly
referred to as a LIMIS system.
Prior devices and systems, as exemplified by those discussed above, have
been directed to the use of proximity detection. Typically, these devices
use a radio frequency (RF) transponder and a radio frequency (RF)
receiver. Proximity is measured by detection of a signal or by signal
strength. Current proximity devices, therefore, lack the ability of
precisely measuring the location of an object.
One current type of location position system does, however, offer the
advantage of precise location. Such an existing system is known as the
Global Positioning System (GPS). This system includes a number of
satellites in orbit around the Earth. Each satellite produces a continuous
signal which carries both a time component and a space component having a
number of orbital parameters associated therewith. A GPS receiver,
employed in conjunction with an appropriately programed computer, is used
to receive at least four of the satellite signals and therefrom determine
a precise location of the receiver. This location information is typically
presented as longitude, latitude, and altitude. One critical limitation of
the GPS is that it requires the satellites to be "in view" relative to the
receiver. This means that no obstruction can exist between the minimum
number of satellites and the receiver. The standard GPS, therefore, will
not function inside a building since the GPS signal is blocked by glass,
metal, foliage, soil, brick, and various other materials which cause
deflection of the signal. The GPS signal is optimally employed in an
environment such as a flat desert or on the high seas. Thus, while the GPS
has many important uses in wide open spaces, it is not currently available
for use within interior spaces or shielded environments.
In addition to the U.S. patents discussed above, other related references
deal exclusively with outside signals. Such references include, for
example, U.S. Pat. No. 5,051,741 to Wesby; U.S. Pat. No. 5,334,974 to
Simms et al.; and U.S. Pat. No. 4,918,425 to Greenberg et al.
Positioning systems are becoming widely recognized as being more important
in today's society. There is a current need in business and industry to
precisely locate and/or track the movement of people and material assets
such as inventory or capital equipment. Structures such as the World Trade
Center or large factories, which can employ thousands of people, currently
desire the ability to locate people who may require assistance in reaching
their intended destination. This is also true for large theme or amusement
parks and other expansive tourist areas. In addition, this current need
generally applies to people, objects, and inventory whether they may be
located indoors, out-of-doors, or moving therebetween. The prior art
devices and systems discussed above do not meet these needs because they
lack precision or are currently incapable of operating within shielded
environments or interior spaces.
Thus, prior to the present invention disclosed herein below, there has not
been proposed a positioning system that precisely locates an object or
person by utilizing GPS or GPS-type signals in an interior space or
shielded environment.
OBJECTS AND SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to improve position
location systems.
Another object of this invention is to increase the number of situations in
which a GPS-based position location system may be utilized.
It is a further object of the present invention to employ GPS signals in a
position location system which is not limited to use in only open and
unobstructed areas.
Still another object of the present invention is to employ GPS-type signals
in a position location system.
It is still a further object of the present invention to precisely locate
by use of a GPS signal, an object positioned within an interior space.
Yet another object of the present invention is to precisely locate a
stationary or moving object contained within a shielded environment by use
of a GPS-type signal.
An additional object of the present invention is to precisely locate by use
of a GPS signal, an object positioned within a shielded environment.
Yet a further object of the present invention is to precisely locate as a
function of time, an object positioned within an interior space by use of
a GPS-type signal.
It is yet a further object of the present invention to remotely detect the
precise location of an object or person positioned within the interior of
a large structure such as a multi-floor office building, a factory or
warehouse, a manufacturing or processing facility such as a shipbuilding
yard or oil refinery, or also so positioned in a sea going vessel or space
craft.
Yet another additional object of this invention is to remotely detect the
precise location of a person moving about within a theme park, amusement
park, or other expansive tourist area that may be shielded from standard
GPS signals to thereby assist the person in reaching a desired
destination.
Still yet another object of the present invention is to utilize
pseudosatellites to broadcast a corresponding GPS or GPS-type signal
within an interior space or a shielded environment.
It is yet still another additional and further object of the present
invention to precisely locate by use of a GPS or GPS-type signal, an
object or person moving between an interior space or shielded environment
and unobstructed open space.
These and other objects are attained in accordance with the present
invention wherein there is provided a location positioning system for use
in a shielded environment. The system includes a GPS receiver for
receiving GPS signals and transmitting navigational data, a clock recovery
unit for receiving the navigational data and reconstructing an accurate
clock signal, a computer processing unit for receiving the accurate clock
signal and the navigational data, and at least four pseudosatellites
positioned within the shielded environment. One of the at least four
pseudosatellites is non-coplanar relative to the others. The computer
processing unit generates a respective GPS-type signal corresponding to
each of the at least four pseudosatellites, and the respective GPS-type
signal contains new orbital parameters for each corresponding
pseudosatellite. According to one aspect of this invention, the GPS-type
signals are transmitted into the shielded environment to be received by a
receiver device located therein. The receiver device is capable of
transmitting a location signal. In one particular implementation of this
invention, there is further provided a computer and a location receiver
associated therewith. The location receiver is positioned within the
shielded environment to receive the location signal from the receiver
device so that a precise position of the location receiver may be
determined by the computer by processing the location signal. According to
a specific use of this invention, the location device includes a cellular
phone or alternatively a badge capable of being attached to a person
moving within the shielded environment.
According to another embodiment of the present invention there is provided
a personnel location and tracking system for use in a work-place
environment. This embodiment includes a GPS receiver for receiving GPS
signals and transmitting navigational data; a clock recovery unit for
receiving the navigational data and reconstructing an accurate clock
signal; a computer processing unit for receiving the accurate clock signal
and the navigational data; at least four pseudosatellites positioned
within the work-place environment, one of the at least four
pseudosatellites being non-coplanar relative to the others, wherein the
computer processing unit generates a respective GPS-type signal
corresponding to each of the at least four pseudosatellites, the
respective GPS-type signal containing new orbital parameters for each
corresponding pseudosatellite; a receiver device carried by an individual
moving within the work-place environment, the receiver device capable of
transmitting a location signal, the GPS-type signals being transmitted
into the work-place environment to be received by the receiver device; and
computer means having a location receiver associated therewith, the
location receiver being positioned within the work-place environment to
receive the location signal from the receiver device so that a precise
position of the individual carrying the location receiver may be
determined by the computer means by processing the location signal.
In accordance with another embodiment of this invention, there is provided
an inventory location and tracking system for use in a warehouse storage
facility. This embodiment includes a GPS receiver for receiving GPS
signals and transmitting navigational data; a clock recovery unit for
receiving the navigational data and reconstructing an accurate clock
signal; a computer processing unit for receiving the accurate clock signal
and the navigational data; at least four pseudosatellites positioned
within the warehouse storage facility, one of the at least four
pseudosatellites being non-coplanar relative to the others, wherein the
computer processing unit generates a respective GPS-type signal
corresponding to each of the at least four pseudosatellites, the
respective GPS-type signal containing new orbital parameters for each
corresponding pseudosatellite; and a receiver device attached to a
respective item of inventory in warehouse storage facility. This receiver
device is capable of transmitting a location signal and the GPS-type
signals are transmitted into the warehouse storage facility to be received
by the receiver device. This embodiment further includes a computer having
a location receiver associated therewith, the location receiver being
positioned within the warehouse storage facility to receive the location
signal from the receiver device so that a precise position of the
respective item of inventory having the location receiver may be
determined by the computer means by processing the location signal.
According to yet another embodiment of the present invention, there is also
provided a personal communications and location system for use in an
indoor environment. This system similarly includes a GPS receiver for
receiving GPS signals and transmitting navigational data; a clock recovery
unit for receiving the navigational data and reconstructing an accurate
clock signal; a computer processing unit for receiving the accurate clock
signal and the navigational data; at least four pseudosatellites
positioned within the indoor environment, one of the at least four
pseudosatellites being non-coplanar relative to the others, wherein the
computer processing unit generates a respective GPS-type signal
corresponding to each of the at least four pseudosatellites, the
respective GPS-type signal containing new orbital parameters for each
corresponding pseudosatellite; a receiver device in combination with a
cellular phone carried by an individual moving within the indoor
environment, the receiver device capable of transmitting a location
signal, the GPS-type signals being transmitted into the indoor environment
to be received by the receiver device; and a computer having a location
receiver associated therewith. The location receiver is positioned within
the indoor environment to receive the location signal from the receiver
device so that a precise position of the individual carrying the location
receiver may be determined by the computer by processing the location
signal. The cellular phone thus providing a personal communication link
with an operator of the computer.
In still yet a further embodiment of this invention there is provided a
combined positioning system for locating an object moving between a
shielded environment and unobstructed open space. This system includes a
plurality of global positioning satellites in orbit around the Earth, each
of the global positioning satellites broadcasting a standard GPS signal; a
first GPS receiver for receiving the standard GPS signals and transmitting
navigational data; a clock recovery unit for receiving the navigational
data and reconstructing an accurate clock signal; a computer processing
unit for receiving the accurate clock signal and the navigational data; at
least four pseudosatellites positioned within the shielded environment,
one of the at least four pseudosatellites being non-coplanar relative to
the others, wherein the computer processing unit generates a respective
GPS-type signal corresponding to each of the at least four
pseudosatellites, the respective GPS-type signal containing new orbital
parameters for each corresponding pseudosatellite; a receiver device
attached to the moving object, the receiver device capable of transmitting
a location signal, the GPS-type signals being transmitted into the
shielded environment to be received by the receiver device; and a computer
having a location receiver associated therewith, the location receiver
being positioned within the shielded environment to receive the location
signal from the receiver device so that a precise indoor position of the
moving object having the location receiver may be determined by the
computer means by processing the location signal when the object is within
the shielded environment. This embodiment is also provided with a second
GPS receiver attached to the moving object, the second GPS receiver for
receiving the standard GPS signals when the object is in the unobstructed
open space so that a precise outdoor position of the moving object having
the second GPS receiver may be obtained.
Yet another embodiment of this invention is directed to an interior
positioning system having a GPS receiver for receiving GPS signals and
transmitting NAVDAT data, a clock recovery unit for receiving NAVDAT data
and reconstructing an accurate clock signal, a computer for receiving the
accurate clock signal and the NAVDAT data, the computer capable of
calculating pseudosatellite data for at least four pseudosatellites, and
the pseudosatellites capable of transmitting pseudosatellite data signals
from the pseudosatellite data, wherein the pseudosatellite data signals
are used for determining interior position. This embodiment may further
include a second GPS receiver for receiving the pseudosatellite data
signals, the second GPS receiver being capable of using the
pseudosatellite data signals to determine the interior position of the
second GPS receiver, and a link for communication between the second GPS
receiver and the computer. This link may be implemented as a duplex system
capable of relaying the position of the second GPS receiver to the
computer and capable of relaying information from the computer to the
second GPS receiver.
According to another aspect of this invention, there is provided a method
for providing an interior positioning system. This method includes the
steps of receiving GPS signals, reconstructing an accurate clock signal
from the GPS signals, calculating orbital parameters for at least four
pseudosatellites, and transmitting pseudosatellite data signals using the
reconstructed clock signal and orbital parameters for at least four
pseudosatellites. This method may further include generating NAVDAT
information from the received GPS signals, using the NAVDAT information
for calculating the orbital parameters for the pseudosatellites, and
adding offsets to the NAVDAT information when calculating the orbital
parameters, as well as delaying the reconstructed clock signal to account
for different propagation time to each of the pseudosatellites.
In accordance with yet another aspect of this invention there is provided
an interior positioning system having positional data regarding the
physical position of at least four pseudosatellites, a clock unit for
providing an accurate clock signal, a computer for calculating
pseudosatellite data derived from the positional data and the clock
signal, and a transmitter in communication to the computer for
transmitting pseudosatellite data signals derived from the pseudosatellite
data. This embodiment may further include a second GPS receiver for
receiving the pseudosatellite data signals, the second GPS receiver being
capable of using the pseudosatellite data signals to determine its
interior position. In one particular implementation of this embodiment,
there is further provided a link for communication between the second GPS
receiver and the computer. This link may take the form of a duplex system
capable of relaying the position of the second GPS receiver to the
computer and capable of relaying information from the computer to the
second GPS receiver.
According to yet another embodiment of the method of this invention the
following steps are practiced. First, providing positional information
regarding at least four pseudosatellites, then providing an accurate time
signal, also calculating pseudosatellite data for each pseudosatellite by
using the position information, and further transmitting the
pseudosatellite data and the accurate time signal, the transmitting of the
accurate time signal being delayed for each pseudosatellite to account for
propagation delay.
BRIEF DESCRIPTION OF THE DRAWING
Further objects of the present invention together with additional features
contributing thereto and advantages accruing therefrom will be apparent
from the following description of certain preferred embodiments of the
present invention which are shown in the accompanying drawing with like
reference numerals indicating like components throughout, wherein:
FIG. 1 is a graphical representation of a prior art Global Positioning
System;
FIG. 2 is a graphical representation of one embodiment of the interior
positioning system according to the present invention;
FIG. 3 is a graphical representation of another embodiment of the interior
positioning system according to this invention;
FIG. 4 is graphical representation of yet another embodiment of the
interior positioning system according to the teaching of the present
invention;
FIG. 5 is a block diagram of hardware employed in conjunction with the
interior positioning system of this invention;
FIG. 6 is a flow chart of software used in conjunction with the present
interior positioning system;
FIG. 7 is a block diagram showing the overall structure of one embodiment
of the interior positioning system according to this invention;
FIG. 8 is a detailed block diagram further illustrating the clock recovery
unit discussed in conjunction with FIG. 7;
FIG. 9 is a detailed block diagram directed to the modulator as employed in
connection with the present invention;
FIG. 10 is a detailed graphical representation of the structure having an
interior positioning system according to this invention as presented in
Example 1 below; and
FIG. 11 is a block diagram similar to that of FIG. 7, showing the overall
structure of another embodiment of the interior positioning system
according to this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawing and initially to FIG. 1, there is shown a
global positioning system 10 according to the prior art. The system 10 is
illustrative of the currently operating NAVSTAR Global Positioning System
which includes many satellites represented by satellites 12-26 orbiting
the Earth 28. A total of twenty-four (24) are actually used. The orbiting
satellites 12-26 communicate or broadcast signals 30-44, respectively, to
the Earth 28. The signals 30-44 contain two types of information. The
first type of information is precise time encoded information and the
second is extremely accurate encoded position information. A GPS receiver
located at position 45, for example, is able to determine its exact
location by measuring the difference between any four GPS signals and
calculating the spatial distance or range to each satellite. The receiver
then uses this data and the known position of each satellite to determine
its own position in space, or on the surface of the earth. The NAVSTAR
Global Positioning System is more fully described in Aviator's Guide to
GPS by Bill Clarke and The NAVSTAR Global Positioning System by Tom
Logsdon, the teachings of which are herein recognized to comprise part of
the prior art related hereto. The current GPS system, however, does not
function in many situations. Such situations include, for example,
locations within a building structure, inside an urban environment having
a variety of tall structures, under water, inside dense forests, and
underground. Turning now to FIG. 2, there is shown one embodiment of an
internal positioning system 46 according to the present invention. The
illustration of FIG. 2 shows a building 47 having a first room 48, a
second room 50, and a third room 52. Three different uses of the interior
positioning system 46 are illustrated in FIG. 2. These different uses will
be briefly described before further discussing in detail the specific
components of the interior positioning system 46.
In the first use, a badge 64 is enabled to determine its internal position.
The badge 64 may be provided with an optional transmitter (not shown) to
report the badge position. In the second use, a pointer 66 is enabled to
relate its internal position to the position of another known object such
as a television set 68. By establishing the relative position of two
objects, a pointing vector may be determined. In the third use, a cellular
phone 70 is shown as being enabled to determine its location with precise
accuracy and use that location information to beneficial advantage.
In connection with the third use discussed above, it is currently
contemplated that satellites will soon be able to perform spot beam
searches for specific phones in specific cellular regions. For such an
advanced roaming cellular phone system to function appropriately, a
cellular phone must be able to determine its position and communicate this
information when activated in an entirely different area. In this manner,
a Los Angeles based cellular phone could be used in New York City. The
cellular phone 70 is herein currently enabled to function in this manner.
When the self-locating cellular phone 70 is activated in New York City,
the cellular phone 70 reports its interior or exterior position and
thereby activates a new local area. There are thus proposed herein various
configurations of internal positioning system receivers according to the
present invention. The cellular phone 70, for example, contains a standard
GPS receiver which is provided with an interface to the cellular phone
function. The badge 64 and the pointer 66 may contain a more specialized
receiver which responds to multiple messages contained in the GPS-type
signal described below. These messages can contain specialized
information, such as street address, zip codes, area codes and the like,
to enable more specific system functions.
With continuing reference to FIG. 2, the GPS satellites 16-22, for example,
direct GPS signals 34-40, respectively, toward the building 47. The
signals 34-40 are communicated to a receiving and distribution system 54.
The receiving and distribution system 54 distributes corresponding
GPS-type signals to internal antennas or pseudosatellites 56-62, one of
each being positioned in each of the rooms 48-52 as illustrated. The
embodiment of the interior positioning system 46 shown in FIG. 2 employs
four channels which transmit new RF GPS-type signals modulated with
orbital data corresponding to the actual location of pseudosatellites
56-62. The form of the modulation is identical to the form of a standard
GPS signal. The specific data contained is developed internally by the
internal positioning system 46. The receiving and distribution system 54
makes appropriate changes to each of these signals to allow for positional
offset. An example of positional offset is discussed below in conjunction
with FIG. 10.
The rooms 48-52 are preferably electronically isolated from each other.
This ensures that interior positioning system signals from any one room do
not transmit into another room. When the rooms 48-52 are not
electronically isolated from each other, only one set of pseudosatellites
56-62 is required. Alternatively, it is contemplated to share a
pseudosatellite or any combination thereof between two or more different
rooms. This aspect of the present invention is illustrated by
pseudosatellite 62 being shared between the two rooms 50 and 52, as
illustrated in FIG. 2. This type of sharing is possible even when the two
rooms are electronically isolated from each other. The internal
positioning system 46 may be implemented in any single or multiple room
structure as long as the RF carrier frequency, or other carrier frequency,
can penetrate the walls. In addition, the four pseudosatellites are
preferably positioned in the room in opposite diagonal corners to maximize
the distances therebetween so as to in turn, maximize the accuracy of the
positioning capabilities of the internal positioning system 46.
As shown in FIGS. 2 and 3, the badge 64 and cellular phone 70 are enabled
to determine their interior position using a standard GPS receiving
antenna 78, and the receiving and distribution system 54 as next described
in detail.
The distribution system 54 is provided with a computer processing unit 55
that converts each of the standard GPS signals 34-40 into a corresponding
or interior GPS-type signal that includes the GPS time component and a
position component with new orbital parameters. This processing will be
described in further detail below. The GPS-type signals generated by the
processing unit 55 are each hard-wired into a respective and corresponding
pseudosatellite. Thus, the new orbital parameters generated by the
processing unit 55 relate to the exact physical location of each
corresponding pseudosatellite | | |
