(12) United States Patent
`Huang et al.
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 7,826,968 B2
`Nov. 2, 2010
`
`USOO7826968B2
`
`(54) METHOD, DEVICE AND VEHICLE
`UTILIZING THE SAME
`
`(75) Inventors: Peng-Chuan Huang, Hsinchu (TW);
`Chao Chieh Hsu, Taipei County (TW);
`Hong-Hui Chen, Taipei Hsien (TW)
`
`(73) Assignee: Mediatek Inc., Hsin-Chu (TW)
`
`(*) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 809 days.
`
`1/1999 Croyle et al................. TO1,213
`5,862,511 A *
`5.948,043 A * 9/1999 Mathis ....................... TO1,208
`6,448,927 B1 * 9/2002 Ishigaki et al. ......... 342,357.06
`6,559,794 B1* 5/2003 Nakajima et al. ...... 342,357.06
`6,633,814 B2 10/2003 Kohli et al.
`6,662,107 B2 12/2003 Gronemeyer
`6,774,838 B2
`8, 2004 Sun
`6,795,941 B2
`9, 2004 Nickels et al.
`6,812,887 B2 11/2004 Syrjarinne et al.
`7,071,087 B2
`7/2006 Horslund et al.
`7,084,810 B2 * 8/2006 Kitatani ................. 342,357. 12
`7,123,189 B2 * 10/2006 Lalik et al. ............. 342,357.13
`2004/0073361 A1* 4/2004 TZamaloukas et al. ...... TO1,210
`2008/0201066 A1
`8/2008 Kanazawa
`
`(21) Appl. No.: 11/741,926
`(22) Filed:
`Apr. 30, 2007
`(65)
`Prior Publication Data
`US 2008/0270024A1
`Oct. 30, 2008
`(51) Int. Cl.
`(2006.01)
`GOIC 2L/34
`(2010.01)
`GOIS5/02
`(52) U.S. Cl. ....................... 701/213: 701/214; 340/993;
`342/357.12
`A global positioning system (GPS) device including an
`(58) Field of Saisie seash 992,993.3 45. antenna and a baseband unit is disclosed. The antenna
`S
`licati s fil f
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`s h hi
`receives a wireless signal group. The baseband unit processes
`ee application file for complete search history.
`the wireless signal group to generate a position signal. The
`References Cited
`position signal is updated every time interval. The duration of
`the time interval is changed dynamically.
`
`* cited by examiner
`Primary Examiner Tan Q Nguyen
`(74) Attorney, Agent, or Firm—Thomas, Kayden,
`Horstemeyer & Risley
`
`(57)
`
`ABSTRACT
`
`(56)
`
`U.S. PATENT DOCUMENTS
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`5,592,173 A
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`1/1997 Lau et al.
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`9 Claims, 5 Drawing Sheets
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`g"
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`114
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`A-120
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`Exhibit 2011
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`U.S. Patent
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`Nov. 2, 2010
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`Sheet 1 of 5
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`US 7,826,968 B2
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`Exhibit 2011
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`

`

`U.S. Patent
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`Nov. 2, 2010
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`Sheet 2 of 5
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`US 7,826,968 B2
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`(Time/Sec)
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`(Km/hr)
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`FIG. 2A
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`(Time/Sec)
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`(Km/hr)
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`FIG. 2B
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`Exhibit 2011
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`U.S. Patent
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`Nov. 2, 2010
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`Sheet 3 of 5
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`US 7,826,968 B2
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`(Time/Sec)
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`10- - -
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`O
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`2 4
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`FIG. 3
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`(Number)
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`Exhibit 2011
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`U.S. Patent
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`Nov. 2, 2010
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`Sheet 4 of 5
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`US 7,826,968 B2
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`is -
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`P.
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`P,
`P
`FIG. 4A
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`(Time/Sec)
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`P i
`FIG. 4B
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`(Time/Sec)
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`Exhibit 2011
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`U.S. Patent
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`Nov. 2, 2010
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`Sheet 5 of 5
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`US 7,826,968 B2
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`(Time/Sec)
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`Exhibit 2011
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`

`

`1.
`METHOD, DEVICE AND VEHICLE
`UTILIZING THE SAME
`
`US 7,826,968 B2
`
`BACKGROUND OF THE INVENTION
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`1. Field of the Invention
`The invention relates to a method, a global positioning
`system (GPS) device, and a vehicle, and more particularly to
`a method, a GPS device, and a vehicle capable of utilizing the
`global positioning system (GPS) device.
`2. Description of the Related Art
`Global Positioning System (GPS) receivers determine
`location, Velocity, and time by receiving and processing infor
`mation in GPS signals received from GPS satellites that have
`been placed in orbit around the Earth by the United States
`Government. The GPS signal from each satellite carries data
`for the location-in-space of the satellite and time-of-transmis
`sion on carrier frequencies that are the same for all the satel
`lites. The data from each satellite is spread with a pseudo
`random noise (prin) code that is distinct for that satellite. A
`GPS receiver uses the distinct prn code for distinguishing
`between GPS signals from typically at least four satellites and
`then determines its own location, Velocity, and time by Solv
`ing simultaneous equations using the relative times of the
`signals from each of the satellites arriving at the receiver and
`the locations-in-space and times-of-transmission from the
`satellites.
`For the purposes of illustration, assume the GPS receiver
`finds and then updates its own position every one second. If
`the GPS receiver moves much faster, it is notable to imme
`30
`diately locate its own position. To immediately locate the
`position of the GPS receiver, the position locating frequency
`is increased. For example, the GPS receiver locates and then
`updates its own position every 0.1 seconds. More frequent
`updates, however, increase power consumption.
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`25
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`BRIEF SUMMARY OF THE INVENTION
`
`A method and device are provided. An exemplary embodi
`ment of a global positioning system (GPS) device comprises
`an antenna and a baseband unit. The antenna receives a wire
`less signal group. The baseband unit processes the wireless
`signal group to generate a position signal. The position signal
`is updated every time interval. The duration of the time inter
`Val is changed dynamically.
`An exemplary embodiment of a method for the described
`GPS device is described in the following. A wireless signal
`group is received. The wireless signal group is processed to
`generate a position signal. The position signal is updated
`every time interval. The duration of the time interval is
`changed dynamically.
`Vehicles are also provided. An exemplary embodiment of
`vehicle provides a direction signal to the described GPS
`device. The baseband unit generates the position signal
`according to the processed result and the direction signal.
`A detailed description is given in the following embodi
`ments with reference to the accompanying drawings.
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`BRIEF DESCRIPTION OF THE DRAWINGS
`
`The invention can be more fully understood by referring to
`the following detailed description and examples with refer
`ences made to the accompanying drawings, wherein:
`FIG. 1 is a schematic diagram of an exemplary embodi
`ment of a global positioning system (GPS) device;
`FIG. 2A shows a mapping function corresponding to
`instances of generating a position signal by the baseband unit
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`122 during a one second period and the speed of movement of
`movement of the GPS device 100:
`FIG.2B shows another mapping function corresponding to
`instances of generating a position signal by baseband unit 122
`during a one second period and the speed of movement of the
`GPS device 100:
`FIG. 3 shows a mapping function corresponding to
`instances of generating a position signal by baseband unit 122
`during a one second period and the number of satellites,
`FIG. 4A is a schematic diagram of a path of movement;
`FIG. 4B shows a mapping function corresponding to
`instances of generating a position signal by baseband unit 122
`during a one second period and only one path;
`FIG.4C shows another mapping function corresponding to
`instances of generating a position signal by baseband unit 122
`during a one second period and only one path; and
`FIG. 5 shows a mapping function corresponding to
`instances of generating a position signal by baseband unit 122
`during a one second period and the remaining capacity of the
`battery.
`
`DETAILED DESCRIPTION OF THE INVENTION
`
`The following description is of the best-contemplated
`mode of carrying out the invention. This description is made
`for the purpose of illustrating the general principles of the
`invention and should not be taken in a limiting sense. The
`scope of the invention is best determined by reference to the
`appended claims.
`FIG. 1 is a schematic diagram of an exemplary embodi
`ment of a global positioning system (GPS) device. The GPS
`device 100 comprises an antenna 121 and a baseband unit
`122. Antenna 121 receives a wireless signal group. In this
`embodiment, antenna 121 continuously receives the wireless
`signal group provided by satellites 111-114. In some
`embodiments, antenna 121 determines whether to receive the
`wireless signal group according to a control signal (not
`shown). The control signal is provided by baseband unit 122
`or other elements. When the control signal is activated,
`antenna 121 receives the wireless signal group. When the
`control signal is de-activated, antenna 121 does not receive
`the wireless signal group. Baseband unit 122 processes the
`wireless signal group to generate a position signal S. The
`position signal is updated every time interval. The duration of
`the time interval is changed dynamically to control the times
`of the position signal S. generated by baseband unit 122
`during a one second period, or the position locating frequency
`of the GPS device 100. In this embodiment, the duration of
`the time interval is changed according to a speed of movement
`or a direction of movement of the GPS device 100, a remain
`ing battery capacity (not shown) of the GPS device 100, or the
`number of the satellites.
`For example, the speed of movement of the GPS device 100
`is obtained according to two sets of position signals generated
`by baseband unit 122. When the speed of movement of the
`GPS device 100 exceeds a preset value, the duration of the
`time interval is reduced in order to more quickly obtain the
`position of the GPS device 100. FIG. 2A shows a mapping
`function corresponding to instances of generating a position
`signal by baseband unit 122 during a one second period and
`the speed of movement of the GPS device 100. When the
`speed of movement of the GPS device 100 exceeds 100 (Km/
`hr), the position signal is generated by baseband unit 122 10
`times during a one second period. In other words, the position
`signal is generated by baseband unit 122 once every 0.1
`seconds. Thus, the position locating frequency of the GPS
`device 100 is 10 Hz. When the speed of movement of the GPS
`Exhibit 2011
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`

`

`3
`device 100 is approximately 50(Km/hr), the position signal is
`generated by baseband unit 1225 times during a one second
`period. In other words, the position signal is generated by
`baseband unit 122 once every 0.2 seconds. Thus, the position
`locating frequency of the GPS device 100 is 5 Hz. In sum
`mary, the frequency of generating the position signal by base
`band unit 122 is higher when the speed of movement of the
`GPS device 100 is faster. FIG. 2B shows anther mapping
`function corresponding to instances of generating a position
`signal by baseband unit 122 during a one second period and
`the speed of movement of the GPS device 100. When the
`speed of movement of the GPS device 100 is less than a preset
`value. Such as 200Km/hr), the position signal is generated by
`baseband unit 122 once during a one second period.
`In some embodiments, the duration of the time interval
`corresponds to the intensity of the wireless signal group.
`When the wireless signal group is provided by two satellites,
`baseband unit 122 is unable to generate the position signal St.
`Thus, the duration of the time interval is increased to reduce
`power consumption. FIG.3 shows a mapping function corre
`sponding to instances of generating a position signal by base
`band unit 122 during a one second period and the number of
`satellites. When four satellites provide the wireless signal
`group, the position signal is generated by baseband unit 122
`10 times during a one second period. Thus, the position locat
`ing frequency of the GPS device 100 is 10 Hz. When two
`satellites provide the wireless signal group, baseband unit 122
`stops generating the position signal. Thus, the position locat
`ing frequency of the GPS device 100 is 0 Hz. In some embodi
`ments, when two satellites provide the wireless signal group,
`the position signal is generated by baseband unit 122 only
`once by a long time interval. In other words, the position
`locating frequency of the GPS device 100 is a minimum
`frequency more than 0 Hz.
`As shown in FIG. 1, the GPS device 100 further comprises
`a radio frequency (RF) unit 123, a navigation unit 124, a map
`unit 125, and a processing unit 126. In some embodiments,
`the GPS device 100 selectively comprises one or a combina
`tion of RF unit 123, navigation unit 124, map unit 125, and
`processing unit 126 according to user requirements.
`RF unit 123 is coupled between antenna 121 and baseband
`unit 122 to transform the wireless signal group. Baseband unit
`122 receives a transforming signal generated by RF unit 123
`for generating the position signal. Because baseband unit 122
`generates the position signal S, by a time interval, RF unit 123
`generates the transforming signal by the time interval. In this
`embodiment, RF unit 123 transforms the wireless signal
`group to generate a transforming signal Ss, when receiving
`the control signal S. provided by baseband unit 122.
`Navigation unit 124 displays the position of the GPS
`device 100 on a display panel (not shown) according to the
`position signal S, and a map information S, provided by map
`unit 125. The display panel not only displays a map, the
`display unit also displays the position of the GPS device 100.
`Thus, a movement path of the GPS device 100 is immediately
`obtained by a user.
`When the GPS device 100 moves along a specific path,
`Such as on a straight road or a curvy road, navigation unit 124
`provides a control signal S to baseband unit 122 for chang
`ing the duration of the time interval. FIG. 4A is a schematic
`diagram of a path of movement. Assuming a vehicle utilizing
`the GPS device 100 moves to the direction of the arrow in
`FIG. 4A. Because the moving path is confined, the path of
`movement is divided into a plurality of segments. For
`example, the path of movement is divided into a beginning
`segment P, a middle segment P, and an end segment P.
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`In the beginning segment P, the probability of changing
`the direction of movement of the GPS device 100 is gradually
`reduced Such that the number of times the position signal is
`generated by baseband unit 122 during a one second period is
`gradually reduced, or the duration of the time interval is
`increased. Thus, the position locating frequency of the GPS
`device 100 is gradually reduced. In the middle segment P.
`the probability of changing the direction of movement is
`lower Such that the number of times the position signal is
`generated by baseband unit 122 during a one second period is
`maintained at a preset value. Thus, the position locating fre
`quency of the GPS device is reduced. In some embodiments,
`baseband unit 122 stops generating the position signal. Thus,
`the position locating frequency of the GPS device 100 is zero.
`In the end segment Ps, the probability of changing the direc
`tion of movement is gradually increased Such that the number
`of times the position signal is generated by baseband unit 122
`during a one second period is gradually increased, or the
`duration of the time interval is reduced. Thus, the position
`locating frequency of the GPS device is gradually increased
`to obtain the correct position of the GPS device 100.
`FIG. 4B shows a mapping function corresponding to
`instances of a position signal generated by baseband unit 122
`during a one second period and only one path. In the begin
`ning segment P, the position locating frequency of the GPS
`device 100 is gradually reduced from 10 Hz to 2 Hz. In the
`middle segment P, the probability of changing the direction
`of movement is lower, thus, the position locating frequency of
`the GPS device 100 is maintained at 2 Hz. In the end segment
`Ps, since the probability of changing the direction of move
`ment is higher, the frequency of generating the position signal
`is increased. Thus, the position locating frequency of the GPS
`device 100 is gradually increased from 2 Hz to 10 Hz.
`FIG.4C shows another mapping function corresponding to
`instances of generating a position signal by baseband unit 122
`during a one second period and only one path. FIG. 4C is
`similar to FIG. 4B with the exception that the position locat
`ing frequency of the GPS device 100 is not maintained in the
`middle segment P. As shown in FIG. 4C, when the GPS
`device 100 moves in a beginning section of the middle seg
`ment P, the position locating frequency of the GPS device
`100 is maintained at 2 Hz and the position locating frequency
`of the GPS device 100 is then reduced to 0 HZ. When the GPS
`device 100 moves in an end section of the middle segment P.
`the position locating frequency of the GPS device 100 is
`increased from 0 Hz to 2 Hz.
`With the map information provided by the map unit 125
`(shown in FIG. 1), the position of a moving car along a
`specific path can be determined by VT, where V is the
`velocity of the car and T is the time period. The velocity of a
`car can be obtained by the velocity detector inherently
`equipped in the car. V can be a function of time. That is, V can
`vary with time. The total path the car travels would be an
`integration of AV* At. Therefore, position locating is not
`needed under this situation and the position locating fre
`quency can be 0 HZ.
`In another embodiment, if an object (a car for example) is
`moving at a constant speed Vc, the total traveling path would
`beVcT. For example, some cars have a constant speed cruise
`mode. That is, under this mode, a car can move at a constant
`speed unless the user steps on the brake. When the car is in the
`constant speed cruise mode, a constant speed signal can be
`sent to the GPS device 100 and the GPS device 100 stops
`position locating from the satellites. The GPS device 100
`obtains the constant speed Vc before the car enters the con
`stant speed cruise mode. The constant speed Vc is determined
`by prior position locating information. The GPS device 100
`
`Exhibit 2011
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`

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`US 7,826,968 B2
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`determines the position of the car according to the constant
`speedVc, the elapsed time T, and the map information. If the
`user deactivates the constant speed cruise mode, the GPS
`device 100 resumes position locating from satellites.
`In some embodiments, the position locating frequency of
`the GPS device 100 is determined according to a remaining
`capacity of a battery (not shown) of the GPS device 100. As
`shown in FIG. 1, processing unit 126 detects the remaining
`capacity of the battery. The duration of the time interval is
`changed according to the detected result. When the remaining
`capacity of the battery exceeds a preset value, the duration of
`the time interval is reduced. Similarly, if the remaining capac
`ity of the battery is less than the preset value, the duration of
`the time interval is lengthened. Ifa user does not want to lower
`the position locating frequency, he can choose to deactivate
`the function mentioned above and maintain the same position
`locating frequency while the remaining capacity of the bat
`tery is low.
`FIG. 5 shows a mapping function corresponding to
`instances of generating a position signal by baseband unit 122
`during a one second period and the remaining capacity of the
`battery. When the remaining capacity of the battery is 75%,
`the position signal is generated by baseband unit 122 10 times
`during a one second period, or the position signal is generated
`by baseband unit 122 once every 0.1 seconds. Thus, the
`position locating frequency of the GPS device 100 is 10 Hz.
`When the remaining capacity of the battery is 25%, the posi
`tion signal is generated by baseband unit 122 twice during a
`one second period, or the position signal is generated by
`baseband unit 122 once every 0.5 seconds. Thus, the position
`locating frequency of the GPS device 100 is 2 Hz.
`In some embodiments, if the GPS device 100 is applied in
`a vehicle, a speed signal and a direction signal of the vehicle
`are obtained by processing unit 126. Baseband unit 122 gen
`erates the position signal according to the previous wireless
`signal group, the speed signal, and the direction signal. If
`antenna 121 is unable to receive the wireless signal group
`provided by satellites, baseband unit 122 coordinates with the
`previous wireless signal group, the speed signal, and the
`direction signal to estimate the position of the vehicle.
`In Summary, the number of times the position signal is
`generated during a one second period is not fixed. In a specific
`case, such as the speed of movement of the GPS device 100,
`the remaining capacity of the battery, or strength of the wire
`less signal group exceeds a preset value, the number of times
`the position signal is generated by baseband unit is reduced,
`or the duration of the time interval is increased. Thus, the
`power consumption is reduced because the position locating
`frequency is reduced.
`While the invention has been described by way of example
`and in terms of the preferred embodiments, it is to be under
`stood that the invention is not limited to the disclosed embodi
`ments. To the contrary, it is intended to cover various modi
`fications and similar arrangements (as would be apparent to
`those skilled in the art). Therefore, the scope of the appended
`
`6
`claims should be accorded the broadest interpretation so as to
`encompass all such modifications and similar arrangements.
`What is claimed is:
`1. A global positioning system (GPS) device, comprising:
`an antenna receiving a wireless signal group from at least
`two satellites; and
`a baseband unit processing the wireless signal group to
`generate a position signal, wherein the position signal is
`updated every time interval, and the duration of the time
`interval is changed dynamically according to at least one
`of:
`a remaining capacity of a power source of the GPS device,
`a number of the satellites, and
`a movement path of the GPS device.
`2. The GPS device as claimed in claim 1, wherein the
`duration of the time interval is reduced when the remaining
`capacity of the battery exceeds a preset value.
`3. The GPS device as claimed in claim 1, wherein the
`duration of the time interval is reduced when the number of
`the satellites exceeds a preset value.
`4. A method for a global positioning system (GPS) device,
`comprising:
`receiving a wireless signal group from at least two satel
`lites:
`processing the wireless signal group to generate a position
`signal; and
`updating the position signal every time interval, wherein
`the duration of the time interval is changed dynamically
`according to at least one of
`a remaining capacity of a power source of the GPS device,
`a number of the satellites, and
`a movement path of the GPS device.
`5. The method as claimed in claim 4, wherein the duration
`of the time interval is reduced when the remaining capacity of
`the battery exceeds a preset value.
`6. The method as claimed in claim 4, wherein the duration
`of the time interval is reduced when the number of the satel
`lites exceeds a preset value.
`7. The method as claimed in claim 4, wherein the duration
`of the time interval is reduced when the GPS device moves in
`a single direction.
`8. The GPS device as claimed in claim 1, wherein the
`duration of the time interval is reduced when the GPS device
`moves in a single direction.
`9. A baseband unit of a global positioning system (GPS)
`device with an antenna receiving a wireless signal group from
`at least two satellites, said baseband unit processing the wire
`less signal group to generate a position signal, wherein the
`position signal is updated every time interval, and the dura
`tion of the time interval is changed dynamically according to
`at least one of:
`a remaining capacity of a power source of the GPS device,
`a number of the satellites, and
`a movement path of the GPS device.
`
`k
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`k
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`k
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`k
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`k
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`Exhibit 2011
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`