PN generators for spread spectrum communications systems

• US 8,611,310 B2
• Filed: 09/10/2003
• Issued: 12/17/2013
• Est. Priority Date: 01/31/2000
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Black, Peter J., Padovani, Roberto, Weaver, Lindsay A. Jr.
• Primary Examiner(s): Phillips, Hassan
• Assistant Examiner(s): Tsegaye, Saba
• Application Number:
  US10/659,831
• Publication Number:
  US 20040052302A1
• Time in Patent Office: 3,751 Days
• Field of Search: 370/335, 370/342, 375/130, 375/146, 375/147, 375/140, 375/141, 708/250, 714/728, 714/739
• US Class Current: 370/335
• CPC Class Codes: H03K 3/84 Generating pulses having a predetermined statistical distribution of a parameter, e.g. random pulse generators
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04J 13/0022 PN, e.g. Kronecker
• CPC Class Codes: H04J 13/10 Code generation

Abstract

Techniques to improve the acquisition process in a spread spectrum environment. The signals from different CDMA systems are spread with different sets of PN sequences, with the PN sequences in each set being uncorrelated to the PN sequences in the other sets. The mobile station can attempt to acquire the pilot signal by processing the received signal with a first set of PN sequences corresponding to a first hypothesis of the particular signal being acquired. If acquisition of the pilot signal fails, a second set of PN sequences corresponding to a second hypothesis is selected and used to process the received signal. The PN sequences in the second set are uncorrelated to the PN sequences in the first set.

Claims

1. An apparatus, comprising:

a first device to transmit at a first frequency;

a first PN generator to generate a first PN sequence at a first offset, the first PN sequence comprising a first in-phase PN sequence and a first quadrature PN sequence;

a first spreader to receive and spread a first pilot data with the first PN sequence;

a second device to transmit at a second frequency, the second device co-sited with the first device;

a second PN generator to generate a second PN sequence at a second offset, the second PN sequence comprising a second in-phase PN sequence and a second quadrature PN sequence, wherein the first PN sequence is generated from equations different from equations used to generate the second PN sequence, and wherein the first in-phase PN sequence is uncorrelated with the second in-phase PN sequence and the first quadrature PN sequence is uncorrelated with the second quadrature PN sequence; and

a second spreader to receive and spread a second pilot data with the second PN sequence in an area co-sited with the spread first pilot data.

2. The apparatus of claim 1, wherein the first frequency uses a different CDMA format than the second frequency.

3. The apparatus of claim 2, wherein the first frequency is generated from a first CDMA format chosen from the group consisting of PCS, IS-95, IS-98, WCDMA, UTRA, IS-2000 and CDMA 2000, the second frequency is generated from a second CDMA format chosen from the group consisting of PCS, IS-95, IS-98, WCDMA, UTRA, IS-2000 and CDMA 2000 and wherein, the first CDMA format is different from the second CDMA format.

4. The apparatus of claim 1, wherein the first PN generator generates the first PN sequence based on characteristic polynomials comprising:

P_I,1=x¹⁵+x¹³+x⁹+x⁸+x⁷+x⁵+1, and

P_Q,1=x¹⁵+x¹²+x¹¹+x¹⁰+x⁶+x⁵+x⁴+x³+1.

5. The apparatus of claim 1, wherein the second PN generator generates the second PN sequence based on characteristic polynomials comprising:

P_I,2=x¹⁵+x¹⁰+x⁸+x⁷+x⁶+x²+1, and

P_Q,2=x¹⁵+x¹²+x¹¹+x¹⁰+x⁹+x⁵+x⁴+x³+1.

6. A method, comprising:

generating a first PN sequence at a first offset, the first PN sequence comprising a first in-phase PN sequence and a first quadrature PN sequence;

spreading a first pilot data with the first PN sequence;

generating a second PN sequence at a second offset, the second PN sequence comprising a second in-phase PN sequence and a second quadrature PN sequence, wherein the first PN sequence is generated from equations different from equations used to generate the second PN sequence, and wherein the first in-phase PN sequence is uncorrelated with the second in-phase PN sequence and the first quadrature PN sequence is uncorrelated with the second quadrature PN sequence; and

spreading a second pilot data with the second PN sequence in an area co-sited with the spread first pilot data.

7. The method of claim 6, wherein generating the first PN sequence is based on characteristic polynomials comprising:

P_I,1=x¹⁵+x¹³+x⁹+x⁸+x⁷+x⁵+1, and

P_Q,1=x¹⁵+x¹²+x¹¹+x¹⁰+x⁶+x⁵+x⁴+x³+1.

8. The method of claim 6, wherein generating the second PN sequence is based on characteristic polynomials comprising:

P_I,2=x¹⁵+x¹⁰+x⁸+x⁷+x⁶+x²+1, and

P_Q,2=x¹⁵+x¹²+x¹¹+x¹⁰+x⁹+x⁵+x⁴+x³+1.

9. An apparatus, comprising:

means for generating a first PN sequence at a first offset, the first PN sequence comprising a first in-phase PN sequence and a first quadrature PN sequence;

means for spreading a first pilot data with the first PN sequence;

means for generating a second PN sequence at a second offset, the second PN sequence comprising a second in-phase PN sequence and a second quadrature PN sequence, wherein the first PN sequence is generated from equations different from equations used to generate the second PN sequence, and wherein the first in-phase PN sequence is uncorrelated with the second in-phase PN sequence and the first quadrature PN sequence is uncorrelated with the second quadrature PN sequence; and

means for spreading a second pilot data with the second PN sequence in an area co-sited with the spread first pilot data.

10. The apparatus of claim 9, wherein generating the first PN sequence is based on characteristic polynomials comprising:

P_I,1=x¹⁵+x¹³+x⁹+x⁸+x⁷+x⁵+1, and

P_Q,1=x¹⁵+x¹²+x¹¹+x¹⁰+x⁶+x⁵+x⁴+x³+1.

11. The apparatus of claim 9, wherein generating the second PN sequence is based on characteristic polynomials comprising:

P_I,2=x¹⁵+x¹⁰+x⁸+x⁷+x⁶+x²+1, and

P_Q,2=x¹⁵+x¹²+x¹¹+x¹⁰+x⁹+x⁵+x⁴+x³+1.

12. An apparatus for wireless communication, comprising:

a processing system configured to;

generate a first PN sequence at a first offset, the first PN sequence comprising a first in-phase PN sequence and a first quadrature PN sequence;

spread a first pilot data with the first PN sequence;

generate a second PN sequence at a second offset, the second PN sequence comprising a second in-phase PN sequence and a second quadrature PN sequence, wherein the first PN sequence is generated from equations different from equations used to generate the second PN sequence, and wherein the first in-phase PN sequence is uncorrelated with the second in-phase PN sequence and the first quadrature PN sequence is uncorrelated with the second quadrature PN sequence; and

spread a second pilot data with the second PN sequence in an area co-sited with the spread first pilot data.

13. The apparatus of claim 12, wherein the second PN sequence is generated based on characteristic polynomials comprising:

P_I,2=x¹⁵+x¹⁰+x⁸+x⁷+x⁶+x²+1, and

P_Q,2=x¹⁵+x¹²+x¹¹+x¹⁰+x⁹+x⁵+x⁴+x³+1.

14. A computer program product, comprising:

a non-transitory computer-readable medium comprising code for;

generating a first PN sequence at a first offset, the first PN sequence comprising a first in-phase PN sequence and a first quadrature PN sequence;

spreading a first pilot data with the first PN sequence;

generating a second PN sequence at a second offset, the second PN sequence comprising a second in-phase PN sequence and a second quadrature PN sequence, wherein the first PN sequence is generated from equations different from equations used to generate the second PN sequence, and wherein the first in-phase PN sequence is uncorrelated with the second in-phase PN sequence and the first quadrature PN sequence is uncorrelated with the second quadrature PN sequence; and

spreading a second pilot data with the second PN sequence in an area co-sited with the spread first pilot data.

15. The computer program product of claim 14, wherein generating the second PN sequence is based on characteristic polynomials comprising:

P_I,2=x¹⁵+x¹⁰+x⁸+x⁷+x⁶+x²+1, and

P_Q,2=x¹⁵+x¹²+x¹¹+x¹⁰+x⁹+x⁵+x⁴+x³+1.