Reception Of A Spread Spectrum Modulated Signal

• US 20070286265A1
• Filed: 04/21/2005
• Published: 12/13/2007
• Est. Priority Date: 04/23/2004
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Nokia Corporation
• Inventors: Valio, Harri, Pietila, Samuli
• Granted Patent: US 7,839,915 B2
• Time in Patent Office: Days
• US Class Current: 375/152
• CPC Class Codes: H04B 1/7077 Multi-step acquisition, e.g. multi-dwell, coarse-fine or validation
• CPC Class Codes: H04B 2201/70707 Efficiency-related aspects
• CPC Class Codes: H04B 2201/70715 with application-specific features

Abstract

The present invention relates to a receiver for receiving a spread spectrum modulated signal, comprising a sampler for forming samples of a received signal, at least one reference code block for generating at least first and second reference codes, and a correlation block. The correlation block forms first and second reference code parts from at least one reference code, and correlates the first reference code part with the sample string to form first correlation part results, and correlates the second reference code part with the sample string to form second correlation part results, wherein the correlations are arranged to be performed at different times and by using the same sample string. The invention also relates to an electronic device comprising a receiver, a module to be used with a receiver, a system comprising a transmitter and a receiver for receiving the transmitted signal, a method and a computer software product.

Claims

1. A receiver for comprising:

a sampler for forming samples of a received spread spectrum modulated signal,

at least one reference code block for generating at least one reference code, and

a correlation block,

comprising;

a first register element for forming first and second reference code parts from at least one reference code,

a second register element for forming a sample string from samples formed of the received signal, and

a correlator for correlating the first reference code part with the sample string to form first correlation part results, and for correlating the second reference code part with the sample string to form second correlation part results, wherein said correlator is configured to perform said correlations at different times and by using the same sample string,

wherein said first and second reference code parts are adapted to be periodically updated.

2. The receiver according to claim 1 comprising a combinating element for combining the first correlation part results to form a first correlation result, and for combining the second correlation part results to form a second correlation result.

3. The receiver according to claim 1 comprising at least a first channel-specific reference code block for generating a first reference code, and a second channel-specific reference code block for generating a second reference code, wherein said first register element is configured to form the first reference code part of at least a part of the first reference code, and the second reference code part of a part of the second reference code.

4. The receiver according to claim 1, comprising a controlling element configured to update the sample string and to perform said correlations after the formation of a new sample.

5. The receiver according to claim 1, wherein said first register element comprises a code shift register and a code register for each reference code, a data transfer element for transferring data of the code shift register into the code register, that said second register element comprises a sample shift register, and said controlling element is configured to transfer the data of said code shift register and sample shift register to store a new sample in the sample shift register and to read new reference code data into the code shift register after the formation of the new sample, and that said code shift register, code register and sample shift register are equal in length.

6. The receiver according to claim 5, wherein the sample shift register and the code shift register have a determined length, wherein said controlling element is configured to transfer the data of the code shift register into the code register after the formation of the number of samples corresponding to said length.

7. The receiver according to claim 5 wherein said correlation block comprises two or more code registers for each code shift register, and wherein the receiver comprises a multiplexing element for performing the correlation in a multiplexed manner between the sample shift register and each code register.

8. The receiver according to claim 1 wherein said at least one channel-specific reference code block comprises a code generator for generating said at least one reference code.

9. The receiver according to claim 1 wherein said at least one reference code is stored in a memory.

10. The receiver according to claim 1, wherein said correlator comprises a multiplier for multiplying the first reference code part with the sample string to form first correlation part results, and for multiplying the second reference code part with the sample string to form second correlation part results.

11. The receiver according to claim 1 wherein said combinating element comprises a summer for summing the correlation part results to form a correlation result.

12. An electronic device comprising a receiver for receiving a spread spectrum modulated signal, which comprises at least:

a sampler for forming samples of a received signal,

at least one reference code block for generating at least one reference code, and

a correlation block comprising;

a first register element for forming first and second reference code parts from at least one reference code,

a second register element for forming a sample string from samples formed of the received signal, and

a correlator for correlating the first reference code part with the sample string to form first correlation part results, and for correlating the second reference code part with the sample string to form second correlation part results, wherein said correlator is configured to perform said correlations at different times and by using the same sample string,

wherein said first and second reference code parts are adapted to be periodically updated.

13. The electronic device according to claim 12 comprising a combinating element for combining the first correlation part results to form a first correlation result, and for combining the second correlation part results to form a second correlation result.

14. The electronic device according to claim 12 wherein it comprises a controlling element configured to update the sample string and to perform said first and second correlations after the formation of a new sample.

15. The electronic device according to claim 12, wherein said first register element comprises a code shift register and a code register for each reference code, a data transfer element for transferring data of the code shift register into the code register, said second register element comprises a sample shift register, and said controlling element is configured to transfer the data of said code shift register and sample shift register, to store a new sample in the sample shift register and to read new reference code data into the code shift register after the formation of the new sample, and that said code shift register, code register and sample shift register are equal in length.

16. The electronic device according to claim 15, wherein the sample shift register and the code shift register have a determined length, wherein said controlling element is configured to transfer the data of the code shift register into the code register after the formation of the number of samples corresponding to said length.

17. The electronic device according to claim 15 wherein said correlation block comprises two or more code registers for each code shift register, wherein the electronic device comprises a multiplexing element for performing the correlation in a multiplexed manner between the sample shift register and each code register.

18. A system comprising a transmitting station for transmitting a spread spectrum modulated signal, a receiver for receiving a spread spectrum modulated signal, which comprises at least:

a sampler for forming samples of a received signal,

at least one reference code block for generating at least one reference code, and

a correlation block, comprising;

a first register element for forming first and second reference code parts from at least one reference code,

a second register element for forming a sample string from samples formed of the received signal, and

a correlator for correlating the first reference code part with the sample string to form first correlation part results, and for correlating the second reference code part with the sample string to form second correlation part results, wherein said correlator is configured to perform said correlations at different times and by using the same sample string,

wherein said first and second reference code parts are adapted to be periodically updated.

19. The system according to claim 18, comprising a combinating element for combining the first correlation part results to form a first correlation result, and for combining the second correlation part results to form a second correlation result.

20. A module comprising:

an input for receiving samples formed of a received signal,

at least one reference code block for generating at least one reference code, and

a correlation block, comprising;

a first register element for forming first and second reference code parts from at least one reference code,

a second register element for forming a sample string from samples formed of the received signal, and

a correlator for correlating the first reference code part with the sample string to form first correlation part results, and for correlating the second reference code part with the sample string to form second correlation part results, wherein said correlator is configured to perform said correlations at different times and by using the same sample string,

wherein said first and second reference code parts are adapted to be periodically updated.

21. The module according to claim 20 comprising a combinating element for combining the first correlation part results to form a first correlation result, and for combining the second correlation part results to form a second correlation result.

22. The module according to claim 20 configured to update the sample string and for performing said first and second correlations after the formation of a new sample.

23. The module according to claim 20, wherein said first register element comprises a code shift register and a code register for each reference code, a data transfer element for transferring data of the code shift register into the code register, said second register element comprises a sample shift register, and which module is configured to transfer the data of said code shift register and sample shift register, to store a new sample in the sample shift register and to read new reference code data into the code shift register after the formation of the new sample, and that said code shift register, code register and sample shift register are equal in length.

24. The module according to claim 23, wherein the sample shift register and the code shift register have a determined length, wherein the module is configured to transfer the data of the code shift register into the code register after the formation of the number of samples corresponding to said length.

25. The module according to claim 23 wherein said correlation block comprises two or more code registers for each code shift register, wherein the module comprises a multiplexing element for performing the correlation in a multiplexed manner between the sample shift register and each code register.

26. A method comprising:

receiving samples of a received spread spectrum modulated signal,

generating at least one reference code, and

performing a correlation between said at least one reference code and the received signal,

forming first and second reference code parts from at least one reference code,

forming a sample string of the samples formed of the received signal,

correlating the first reference code part with the sample string to form first correlation part results, and correlating the second reference code part with the sample string to form second correlation part results, said correlations being performed at different times and by using the same sample string, and

periodically updating said first and second reference code parts.

27. The method according to claim 26 comprising combining the first correlation part results to form a first correlation result, and combining the second correlation part results to form a second correlation result.

28. The method according to claim 26 comprising updating the sample string, wherein said correlations are performed after the formation of a new sample.

29. The method according to claim 26 comprising:

inputting the reference code in a code shift register, and

inputting samples of the sample string in a sample shift register

wherein the rate the reference code is input in the code shift register is dependent on the rate at which samples of the sample string are input in the sample shift register.

30. The method according to claim 29, wherein the sample shift register and the code shift register have a determined length, wherein the method comprises transferring the bits of the reference code input in the code shift register to the code register after the formation of the number of samples corresponding to said length.

31. A computer software product which comprises machine executable commands stored on a readable medium for execution by a processor:

for forming samples of a received spread spectrum modulated signal,

for generating at least one reference code, and

for performing a correlation between said at least one reference code and the received signal,

for forming first and second reference code parts from at least one reference code,

for forming a sample string from samples formed of the received signal,

for correlating the first reference code part with the sample string to form first correlation part results, and for correlating the second reference code part with the sample string to form second correlation part results, said correlations being performed at different times and by using the same sample string, and

periodically updating said first and second reference code parts.

32. The computer software product according to claim 31, comprising machine executable program commands for combining the first correlation part results to form a first correlation result, and for combining the second correlation part results to form a second correlation result.

33. A module comprising:

a first input for receiving samples formed of a received signal,

a second input for receiving at least one reference code, and

a correlation block comprising;

a first register element for forming first and second reference code parts from at least one reference code,

a second register element for forming a sample string from samples formed of the received signal, and

a correlator for correlating the first reference code part with the sample string to form first correlation part results, and for correlating the second reference code part with the sample string to form second correlation part results, wherein said correlator is configured to perform said correlations at different times and by using the same sample string,

wherein said first and second reference code parts are adapted to be periodically updated.

34. A receiver for receiving a spread spectrum modulated signal, comprising:

sampling means for forming samples of a received signal,

at least one reference code block for generating at least one reference code, and

a correlation block comprising;

means for forming first and second reference code parts from at least one reference code,

means for forming a sample string from samples formed of the received signal, and

correlation means for correlating the first reference code part with the sample string to form first correlation part results, and for correlating the second reference code part with the sample string to form second correlation part results, wherein said correlations are arranged to be performed at different times and by using the same sample string,

wherein said first and second reference code parts are adapted to be periodically updated.

35. The receiver of claim 34, comprising means for combining the first correlation part results to form a first correlation result, and for combining the second correlation part results to form a second correlation result.