Determination of the correlation phase between a signal and a replica sequence

1. Method for determining a correlation phase between a signal received from a satellite at a receiver and an available replica sequence comprising

using a matched filter to check various correlation phases, said matched filter

multiplying samples of said received signal with samples of said replica sequence and

summing the resulting products to obtain a correlation value for a specific correlation phase, said method further comprising

shifting samples of said received signal and of said available replica sequence relative to each other for each correlation phase which is checked, and

using results obtained in the calculations for one correlation phase by said matched filter for calculating a subsequent correlation phase, and

determining a current position of said receiver, wherein said received signal comprises a binary sequence,

wherein possible values of said binary sequence are +1 and −1,

wherein C i constitutes a determined correlation value for an i th checked correlation phase, wherein N is a length of said binary sequence, wherein x j+i constitutes a j th sample of said received signal for said i th correlation phase, wherein the samples of said replica sequence are not shifted for different correlation phases which are to be checked, wherein r i constitutes a j th sample of said replica sequence, wherein a set J + comprises the indices j for which (r j =1 & r j−1 =1) OR (r j =−1 & r j−1 =−1), and wherein a correlation value C i+1 for the (i+1) th correlation phase is calculated as:

C

i

+

1

=

-

C

i

-

r

0

⁢

x

i

+

r

N

-

1

⁢

x

i

+

N

+

∑

j

∈

J

+

⁢

⁢

2

*

r

j

⁢

x

j

+

i

.

2. Method according to claim 1 , wherein said matched filter multiplies said samples of said received signal elementwise with samples of said replica sequence.

3. Method for determining a correlation phase between a signal received from a satellite at a receiver and an available replica sequence comprising

using a matched filter to check various correlation phases, said matched filter

multiplying samples of said received signal with samples of said replica sequence and

summing the resulting products to obtain a correlation value for a specific correlation phase, said method further comprising

shifting samples of said received signal and of said available replica sequence relative to each other for each correlation phase which is checked, and

using results obtained in the calculations for one correlation phase by said matched filter for calculating a subsequent correlation phase, and

determining a current position of said receiver,

wherein said received signal comprises a binary sequence,

wherein possible values of said binary sequence are +1 and −1,

wherein C i constitutes the determined correlation value for an i th checked correlation phase i, wherein N is the length of said binary sequence, wherein x j+i constitutes a j th sample of said received signal for said i th correlation phase, wherein the samples of said replica sequence are not shifted for the different correlation phases which are to be checked, wherein r j constitutes a j th samples of a said replica sequence, wherein a set J − comprises the indices j for which (r j =1 & r j−1 =−1) OR (r j =−1 & r j−1 =1), and wherein a correlation value C i+1 for the (i+1) th correlation phase is calculated as:

C

i

+

1

=

C

i

-

r

0

⁢

x

i

+

r

N

-

1

⁢

x

i

+

N

-

∑

j

∈

J

-

⁢

⁢

2

*

r

j

⁢

x

j

+

i

.

4. Method for determining a correlation phase between a signal received from a satellite at a receiver and an available replica sequence comprising

using a matched filter to check various correlation phases, said matched filter

multiplying samples of said received signal with samples of said replica sequence and

summing the resulting products to obtain a correlation value for a specific correlation phase, said method further comprising

shifting samples of said received signal and of said available replica sequence relative to each other for each correlation phase which is checked, and

using results obtained in the calculations for one correlation phase by said matched filter for calculating a subsequent correlation phase, and

determining a current position of said receiver,

wherein said received signal comprises a binary sequence,

wherein possible values of said binary sequence are +1 and −1, wherein C i constitutes a determined correlation value for an i th checked correlation phase, wherein N is the length of said binary sequence, wherein x j+i constitutes a j th sample of said received signal for said i th correlation phase, wherein the samples of said replica sequence are not shifted for the different correlation phases which are to be checked, wherein r j constitutes a j th sample of said replica sequence, wherein a set J + comprises the indices j for which (r j =1 & r j−1 =1) OR (r j =−1 & r j−1 =−1), wherein a set J − comprises the indices j for which (r j =1 & r j−1 =−1) OR (r j =−1 & r j−1 =1), and wherein a correlation value C i+1 for the (i+1) th correlation phase is calculated as:

C

i

+

1

=

-

C

i

-

r

0

⁢

x

i

+

r

N

-

1

⁢

x

i

+

N

+

∑

j

∈

J

+

⁢

⁢

2

*

r

j

⁢

x

j

+

i

,

if the size of said set J − is larger than the size of said set J + , and as:

C

i

+

1

=

C

i

-

r

0

⁢

x

i

+

r

N

-

1

⁢

x

i

+

N

-

∑

j

∈

J

-

⁢

⁢

2

*

r

j

⁢

x

j

+

i

,

if the size of said set J + is larger than the size of said set J − .

5. Method according to claim 1 , further comprising a subsequent coherent and/or noncoherent processing for handling signals of low strength.

6. Method according to claim 1 , wherein said received signal is a code modulated signal, and wherein said replica sequence is a replica code sequence.

7. Method according to claim 6 , wherein said code modulation of said received code modulated signal is a Code Division Multiple Access (CDMA) spread spectrum modulation.

8. Use of a method according to claim 1 in a process for acquisition and/or tracking of signals received at a receiver.

9. Receiver comprising

receiving means for receiving signals; and

processing means for carrying out the method according to claim 2 .

10. Receiver according to claim 9 , which receiver is a receiver of a positioning system.

11. Electronic device comprising a receiver according to claim 9 .

12. Electronic device according to claim 11 , wherein said electronic device is a mobile terminal capable of communicating with a communication network.

13. Device comprising

means for receiving from a receiver information on signals received by said receiver; and

processing means for carrying out the method according to claim 2 .

14. Device according to claim 13 , which device is a network element of a network.

15. System comprising

a receiver comprising means for receiving signals, and means for providing information on received signals; and

a device according to claim 13 .

16. System comprising

a receiver according to claim 9 ; and

a device for providing assistance data to said receiver.

17. System according to claim 16 , wherein said device is a network element of a network.

18. System according to claim 16 , wherein said system is a positioning system.

19. System according to claim 15 , wherein said system is a positioning system.