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US 2003/0119444 A1Published application
Cell search synchronization
AssigneeTexas Instruments Incorporated
InventorHirohisa Yamaguchi
Life of this patent
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Abstract
Cell search synchronization in spread spectrum communications systems using primary and second synchronization codes with symbol partitioning for shorter coherent combinations (despreading) which are combined non-coherently, and Fourier transform analysis automatically adjusts for phase rotation of the despread sub-symbols.
Claims10
A method of communication cell search, comprising:
- (a) receiving a synchronization signal;
- (b) despreading said signal with a first sequence of codes to generate a sequence of sub-symbols;
- (c) computing a discrete Fourier transform of said sequence of sub-symbols from step (b);
- (d) finding a maximum magnitude of said discrete Fourier transform from step (c);
- (e) repeating steps (b)-(d) for a second sequence of codes;
- and
- (f) comparing said maximum from said first sequence of codes and said maximum from said second sequence of codes to select between said first sequence of codes and said second sequence of codes for cell search.
4 more elements
A method of communication cell search, comprising:
- (a) receiving a synchronization signal;
- (b) despreading said signal with a first sequence of codes to generate a sequence of sub-symbols;
- (c) partitioning said sequence of sub-symbols from step (b) into a first set of sub-symbols and a second set of sub-symbols, computing a first coherent combination of said first set of sub-symbols and a second coherent combination of said second set of sub-symbols, and non-coherently combining said first coherent combination and said second coherent combination;
- (d) partitioning said sequence of sub-symbols from step (b) into a third set of sub-symbols and a fourth set of sub-symbols, computing a third coherent combination of said third set of sub-symbols and a fourth coherent combination of said fourth set of sub-symbols, and non-coherently combining said third coherent combination and said fourth coherent combination;
- (e) finding a maximum magnitude of said non-coherent combinations from steps (c) and (d);
- (f) repeating steps (b)-(e) for a second sequence of codes;
- and
- (g) comparing said maximum of step (e) from said first sequence of codes and said maximum of step (e) from said second sequence of codes to select between said first sequence of codes and said second sequence of codes for cell search.
5 more elements
Dependencies are inferred from the claim text.