Method and apparatus for generating scrambling codes
View Patent ↗Wireless transmission techniques are described, including techniques used to generate scrambling codes for use in wireless transmissions, such as spread spectrum transmissions. In some embodiments, scrambling codes may be iteratively generated using multiplicative factors. The multiplicative factors may be predetermined and stored in advance, reducing processing time when the codes are needed. The multiplicative factor iterations may involve predetermined algorithms, such as squaring and powers of two iterations.
1. A method of generating a scrambling code for use in spread spectrum communication, said scrambling code being iteratively defined, said method comprising:
determining, for more than one of said iterations for generating said scrambling code, corresponding multiplicative factors; and
combining said multiplicative factors to determine said scrambling code; wherein
said multiplicative factors correspond to powers of x iterations;
one or more multiplicative factors are determined by squaring a multiplicative factor corresponding to a preceding iteration; and
the multiplicative factor corresponding to the x 0 iteration corresponds to a given input and the multiplicative factors for each of the iterations corresponding to x 1 to x y are generated by squaring a multiplicative factor for the preceding iteration in GF(2), where y is a total number of multiplicative factors required to calculate all scrambling codes.
2. The method according to claim 1 wherein said scrambling code is a scrambling code for use with wideband code division multiple access.
3. The method according to claim 1 wherein said squaring occurs in GF(2).
4. The method according to claim 1 wherein said spread spectrum communication comprises wideband code-division multiple access and wherein multiplicative factors are generated for each of the powers of two iterations from 2 0 to 2 16 .
5. The method according to claim 1 further comprising the step of determining, for the scrambling code to be generated, a required iteration number.
6. The method according to claim 5 further comprising, for said required iteration number, determining a sum of a set of powers of two, for each of said determined set of powers of two, determining a corresponding multiplicative factor, and applying each of said multiplicative factors to generate said scrambling code.
7. Apparatus for generating scrambling code for use in spread spectrum communication, said scrambling code being iteratively defined, said apparatus comprising:
a processor configured to determine, for more than one of said iterations for generating said scrambling code, corresponding multiplicative factors;
said processor being further configured to combine said multiplicative factors to determine said scrambling code; wherein
said processor is configured to generate said multiplicative factors corresponding to powers of x iterations;
said processor is configured to determine said one or more multiplicative factors by squaring a multiplicative factor corresponding to a preceding iteration; and
the multiplicative factor corresponding to the x 0 iteration corresponds to a given input and the multiplicative factors for each of the iterations corresponding to x 1 to x y are generated by squaring a multiplicative factor for the preceding iteration in GF(2), where y is a total number of multiplicative factors required to calculate all scrambling codes.
8. The apparatus according to claim 7 wherein said scrambling code is a scrambling code for use with wideband code division multiple access.
9. The apparatus according to claim 7 wherein said processor is configured to perform said squaring in GF(2).
10. The apparatus according to claim 7 wherein said spread spectrum communication comprises wideband code-division multiple access and wherein said processor is configured to generate multiplicative factors for each of the powers of two iterations from 2 0 to 2 16 .
11. The apparatus according to claim 7 wherein said processor is further configured to determine, for scrambling the code to be generated, a required iteration number.
12. The apparatus according to claim 11 wherein said processor is further configured, for said required iteration number, to determine a sum of a set of powers of two, for each of said determined set of powers of two, determine a corresponding multiplicative factor, and apply each of said multiplicative factors to generate said scrambling code.