Method and a system for positioning of an electronic device, and an electronic device
View Patent ↗A method is provided for determining the position of an electronic device by receiving a code modulated signal transmitted by satellites, and position information of the satellites and time data, and by generating local time data. In the method, delta range measurements are taken for at least four different satellites. For each of said at least four satellites, the velocity of the satellite is determined in relation to the positioning receiver. Furthermore, in the method, the delta range measurement results are replaced in an algorithm applying said delta range measurements and velocities to generate reference data for determining the local time data frequency error and the position. The local time data frequency error and the position are determined by searching for the minimum value of said reference data. A system and an electronic device applying the method are also provided.
1. A method for positioning an electronic device in which a code modulated signal transmitted by satellites, position information of the satellites and time data are received, and local time data is generated, wherein delta range measurements are taken for at least four different satellites, said delta range measurements each providing a value of a rate of change of a delta range with respect to time, wherein for each delta range measurement the satellite velocity is determined in relation to the electronic device, wherein said delta range measurements and velocities are used for generating reference data to determine the frequency error of the local time data and the position of the electronic device, and the minimum value of said reference data is searched.
2. The method according to claim 1 , using an algorithm as said reference data, replacing the delta range measurement results in said algorithm, and finding the minimum value for said algorithm.
3. The method according to claim 2 , wherein said algorithm used is the function ƒ(p({circumflex over (r)} u ,{circumflex over (d)})), in which
p
(
r
^
u
,
d
^
)
=
[
v
1
·
r
1
-
r
^
u
r
1
-
r
^
u
+
d
^
-
ρ
.
1
v
2
·
r
2
-
r
^
u
r
2
-
r
^
u
+
d
^
-
ρ
.
2
⋮
v
n
·
r
n
-
r
^
u
r
n
-
r
^
u
+
d
^
-
ρ
.
n
]
,
v i , i=1 . . . n are said velocity vectors of the satellites in relation to the electronic device,
r i , i=1 . . . n are the position vectors of the satellites,
{dot over (ρ)} i , i=1 . . . n are the delta range measurements,
{circumflex over (r)} u is the estimated position vector of the electronic device,
{circumflex over (d)} is the effect of the estimated frequency error of the electronic device on the delta range measurements, and
n≧4,
wherein in the search for the minimum value, {circumflex over (r)} u and {circumflex over (d)} are determined.
4. The method according to claim 2 , wherein said algorithm used is the function ƒ({circumflex over (r)} u ,{circumflex over (d)})=∥p({circumflex over (r)} u ,{circumflex over (d)})∥ m , in which
p
(
r
^
u
,
d
^
)
=
[
v
1
·
r
1
-
r
^
u
r
1
-
r
^
u
+
d
^
-
ρ
.
1
v
2
·
r
2
-
r
^
u
r
2
-
r
^
u
+
d
^
-
ρ
.
2
⋮
v
n
·
r
n
-
r
^
u
r
n
-
r
^
u
+
d
^
-
ρ
.
n
]
,
v i , i=1 . . . n are said velocity vectors of the satellites in relation to the electronic device,
r i , i=1 . . . n are the position vectors of the satellites,
{dot over (ρ)} i , i=1 . . . n are the delta range measurements,
{circumflex over (r)} u is the estimated position vector of the electronic device,
{circumflex over (d)} is the effect of the estimated frequency error of the electronic device ( 1 ) on the delta range measurements,
m∈R, and
n≧4,
wherein in the search for the minimum value, {circumflex over (r)} u , and {circumflex over (d)} are determined.
5. The method according to claim 4 , wherein m=2.
6. The method according to claim 3 , wherein for the search of the minimum value, the matrix
G
(
x
^
)
=
[
{
r
1
-
r
^
u
r
1
-
r
^
u
×
(
r
1
-
r
^
u
r
1
-
r
^
u
×
v
1
r
1
-
r
^
u
)
}
T
1
{
r
2
-
r
^
u
r
2
-
r
^
u
×
(
r
2
-
r
^
u
r
2
-
r
^
u
×
v
2
r
2
-
r
^
u
)
}
T
1
⋮
⋮
{
r
n
-
r
^
u
r
n
-
r
^
u
×
(
r
n
-
r
^
u
r
n
-
r
^
u
×
v
n
r
n
-
r
^
u
)
}
T
1
]
is solved.
7. The method according to the claim 1 , wherein for the search of the minimum value of the reference value, the minimum value of one or more components of the vector
x
=
[
r
u
d
]
=
[
x
u
y
u
𝓏
u
d
]
∈
R
4
is searched.
8. The method according to the claim 1 , wherein it is assumed that the electronic device is stationary, wherein the velocity vectors of the satellites are used as the velocity vectors.
9. A system comprising receiving means for receiving code modulated signals transmitted by satellites, means for receiving position information of the satellites and time data, and means for generating local time data, wherein the system further comprises means for taking delta range measurements for at least four different satellites wherein said delta range measurements each provide a value of a rate of change of a delta range with respect to time, means for determining the velocity of each of said at least four satellites in relation to the receiving means, means for using said delta range measurements and velocities for generating reference data to determine the frequency error of the local time data and position, and means for searching for the minimum value of said reference data.
10. The system according to claim 9 , wherein an algorithm is arranged to be used as said reference data, that the delta range measurement results are arranged to be placed in said algorithm, and that the means for searching for the minimum value of said reference data comprise means for searching for the minimum value of said algorithm.
11. The system according to claim 10 , wherein said algorithm is the function ƒ(p({circumflex over (r)} u ,{circumflex over (d)})), in which
p
(
r
^
u
,
d
^
)
=
[
v
1
·
r
1
-
r
^
u
r
1
-
r
^
u
+
d
^
-
ρ
.
1
v
2
·
r
2
-
r
^
u
r
2
-
r
^
u
+
d
^
-
ρ
.
2
⋮
v
n
·
r
n
-
r
^
u
r
n
-
r
^
u
+
d
^
-
ρ
.
n
]
,
v i , i=1 . . . n are said velocities of the satellites,
r i , i=1 . . . n are the position data of the satellites,
{dot over (ρ)} i , i=1 . . . n are the delta range measurements,
{circumflex over (r)} u is the position vector of the receiving means, and
{circumflex over (d)} is the effect of the frequency error of the receiving means on the delta range measurements, and
n≧4.
12. The system according to claim 10 , wherein said algorithm is the function ƒ({circumflex over (r)} u ,{circumflex over (d)})=∥p({circumflex over (r)} u , {circumflex over (d)})∥ m , in which
p
(
r
^
u
,
d
^
)
=
[
v
1
·
r
1
-
r
^
u
r
1
-
r
^
u
+
d
^
-
ρ
.
1
v
2
·
r
2
-
r
^
u
r
2
-
r
^
u
+
d
^
-
ρ
.
2
⋮
v
n
·
r
n
-
r
^
u
r
n
-
r
^
u
+
d
^
-
ρ
.
n
]
,
v i , i=1 . . . n are said velocities of the satellites,
r i , i=1 . . . n are the position data of the satellites,
{dot over (ρ)} i , i=1 . . . n are the delta range measurements,
{circumflex over (r)} u is the position vector of the positioning receiver, and
{circumflex over (d)} is the effect of the time frequency error of the positioning receiver on the delta range measurements, and
n≧4.
13. The system according to claim 12 , wherein m=2.
14. The system according to claim 11 , wherein the means for searching for the minimum value of the algorithm comprise means for solving the matrix
G
(
x
^
)
=
[
{
r
1
-
r
^
u
r
1
-
r
^
u
×
(
r
1
-
r
^
u
r
1
-
r
^
u
×
v
1
r
1
-
r
^
u
)
}
T
1
{
r
2
-
r
^
u
r
2
-
r
^
u
×
(
r
2
-
r
^
u
r
2
-
r
^
u
×
v
2
r
2
-
r
^
u
)
}
T
1
⋮
⋮
{
r
n
-
r
^
u
r
n
-
r
^
u
×
(
r
n
-
r
^
u
r
n
-
r
^
u
×
v
n
r
n
-
r
^
u
)
}
T
1
]
.
15. An electronic device comprising means for receiving code modulated signals transmitted by satellites, means for receiving position information of the satellites and time data, and means for generating local time data, wherein the electronic device further comprises means for taking delta range measurements for at least four different satellites wherein said delta range measurements each provide a value of a rate of change of a delta range with respect to time, means for determining the velocities of each of said at least four satellites in relation to the electronic device, means for using said delta range measurements and velocities to generate reference data for determining the frequency error of the local time data and position, and means for searching for the minimum value of said reference data.
16. The electronic device according to claim 15 , wherein an algorithm is arranged to be used as said reference data, that the delta range measurement results are arranged to be replaced in said algorithm, and that the means for searching for the minimum value of said reference data comprise means for searching for the minimum value of said algorithm.
17. The electronic device according to claim 16 , wherein said algorithm is the function ƒ(p({circumflex over (r)} u ,{circumflex over (d)})), in which
p
(
r
^
u
,
d
^
)
=
[
v
1
·
r
1
-
r
^
u
r
1
-
r
^
u
+
d
^
-
ρ
.
1
v
2
·
r
2
-
r
^
u
r
2
-
r
^
u
+
d
^
-
ρ
.
2
⋮
v
n
·
r
n
-
r
^
u
r
n
-
r
^
u
+
d
^
-
ρ
.
n
]
,
v i , i=1 . . . n are said velocities of the satellites,
r i , i=1 . . . n are the position of the satellites,
{dot over (ρ)} i , i=1 . . . n are the delta range measurements, {circumflex over (r)} u is the position vector of the electronic device, and
{circumflex over (d)} is the effect of the frequency error of the electronic device on the delta range measurements, and
n≧4.
18. The electronic device according to claim 15 , wherein it is a positioning receiver.
19. The electronic device according to claim 15 , wherein it is a wireless communication device.