Method in the synchronization of a receiver, and a receiver

• US 7,308,021 B2
• Filed: 04/15/2002
• Issued: 12/11/2007
• Est. Priority Date: 04/20/2001
• Status: Active Grant

• Current Assignee: IoT Innovations LLC (Empire IP LLC)
• Original Assignee: Nokia Corporation
• Inventors: Kontola, Ilkka
• Primary Examiner(s): Ahn, Sam K.
• Application Number:
  US10/122,497
• Publication Number:
  US 20020154681A1
• Time in Patent Office: 2,066 Days
• Field of Search: 375/147, 375/142, 375/143, 375/327, 375/343, 375/346, 375/368, 375/152, 375/149, 375/354, 375/357, 375/372, 375/373, 375/374, 375/369, 708/422, 708/423, 708/424, 708/426, 370/395.62, 370/507, 455/265, 702/89, 713/375, 713/400
• US Class Current: 375/149
• CPC Class Codes: G01S 19/24 Acquisition or tracking or demodulation of signals transmitted by the system synchronisation aspects of direct sequence spread spectrum modulation H04B1/7073
• CPC Class Codes: G01S 19/27 creating, predicting or correcting ephemeris or almanac data within the receiver
• CPC Class Codes: G01S 19/29 carrier including Doppler, related G01S19/246 takes precedence
• CPC Class Codes: H04B 1/7075 with code phase acquisition
• CPC Class Codes: H04B 1/7087 Carrier synchronisation aspects

Abstract

In a method f or synchronizing a receiver with a signal modulated with a spreading code the frequency shift of the transmitted signal and the symbol acquisition of the data transmission are determined. In the method, a guessed data is generated, and the received signal is multiplied with at least two different values of said guessed data, to form spectrum results. The spectrum results formed with said different guessed data are used to determine the frequency shift.

Claims

1. A method for synchronizing a receiver with a transmitted signal modulated with a spreading code and further modulated with information to be transmitted, the method comprising:

determining a frequency shift of the transmitted signal and the symbol acquisition of the data transmission,

forming guessed data representing a guess of the information to be transmitted,

multiplying the received signal with at least two different values of said guessed data to form spectrum results,

determining the frequency shift on the basis of the spectrum results formed with said different guessed data, and

using the determined frequency shift to set an oscillator for synchronizing the receiver.

2. A method according to claim 1, wherein further at least two different phase shifts are selected for the guessed data, wherein the spectrum results are computed for the different guessed data with each phase shift of the guessed data.

3. A method according to claim 1, wherein in each spectrum result, the highest maximum is searched for, and the highest maxima searched for in the different spectrum results are compared, wherein the frequency shift is determined on the basis of the highest maximum which is the greatest of said highest maxima.

4. A method according to claim 1, which comprises a first acquisition step to find out the rough frequency shift of the signal and the acquisition of the spreading code and a second acquisition step, in which the received signal is multiplied with said guessed data, wherein the more precise frequency shift and the symbol acquisition of the data transmission are determined on the basis of the formed spectrum results.

5. A method according to claim 1, wherein the received signal is multiplied with said guessed data after the rough frequency shift of the signal and the acquisition of the spreading code, wherein several different guessed data are formed, and several determinations of the frequency shift and the symbol acquisition of the data transmission are performed, one of said several different guessed data being used in each.

6. A receiver comprising acquisition means for acquisition of a signal modulated with a spreading code and further modulated with information to be transmitted, and determining means for determining the frequency shift of the signal and the symbol acquisition of the data transmission, the receiver also comprising means for generating guessed data representing a guess of the information to be transmitted, means for multiplying the received signal with at least two different values of said guessed data to form spectrum results, and means for determining the frequency shift on the basis of the spectrum results formed with said different guessed data.

7. A receiver according to claim 6, which comprises means for selecting at least two different phase shifts for the guessed data, wherein the spectrum results are arranged to be computed for the different guessed data with each phase shift of the guessed data.

8. A receiver according to claim 6, which comprises means for searching for the highest maximum in each spectrum result, and means for comparing the highest maxima searched in different spectrum results, wherein the frequency shift is arranged to be determined on the basis of the highest maximum which is the highest of said highest maxima.

9. A receiver according to claim 6, which comprises an acquisition block for determining the rough frequency shift of the signal and the acquisition of the spreading code, and a precision acquisition block with means for multiplying the received signal with said guessed data and means for determining the further defined frequency shift and the symbol acquisition of the data transmission on the basis of the formed spectrum results.

10. A receiver according to claim 6, wherein the multiplication of the received signal by said guessed data is arranged to be performed after the acquisition of the rough frequency shift of the signal and the spreading code, wherein the receiver comprises means for generating several different guessed data, and two or more acquisition blocks which are each provided with means for determining the frequency shift and the acquisition of the spreading code by using one of said several different guessed data.

11. A wireless communication device comprising at least one receiver which comprises acquisition means for acquisition of a signal modulated with a spreading code and further modulated with information to be transmitted, and determining means for determining the frequency shift of the signal and the symbol acquisition of the data transmission, the wireless communication device also comprising means for generating a guessed data representing a guess of the information to be transmitted, means for multiplying the received signal by at least two different values of said guessed data to form spectrum results, and determining means for determining the frequency shift on the basis of the spectrum results formed with said different guessed data.