Patent ID: 9306619
Filing Date: 2016-04-05
CPC Classification: H04B

Claim Text:
1. A direct-sequence spread spectrum signal receiving device, comprising: a receiver unit arranged to extract, in a first detection phase, a chip stream from a radio-frequency signal, said chip stream comprising a first chip sequence having a length of one symbol; a chip sequence generating unit arranged to generate, in said first detection phase, a plurality of trial chip sequences on the basis of a first trial chip sequence representing a first trial symbol and on the basis of a plurality of index rotations, each trial chip sequence being index-rotated relative to said first trial chip sequence by one of said index rotations; a correlation unit arranged to determine, in said first detection phase, a plurality of first correlation values on the basis of said plurality of trial chip sequences and on the basis of said first chip sequence, each of said first correlation values indicating a degree of correlation between a respective one of said trial chip sequences and said first chip sequence; and a comparison unit arranged to determine, in said first detection phase, whether a maximum one of said first correlation values exceeds a defined threshold value; wherein said receiving unit is further arranged to initiate a second detection phase in response to said maximum correlation value exceeding said threshold value, wherein said correlation unit is further arranged to determine, in said second detection phase, a plurality of second correlation values on the basis of said plurality of trial chip sequences and on the basis of a second chip sequence contained in said chip stream, said second chip sequence having a length of one symbol, each of said second correlation values indicating a degree of correlation between a respective one of said trial chip sequences and said second chip sequence, wherein said comparison unit is further arranged to determine, in said second detection phase, whether a maximum one of said second correlation values exceeds said defined threshold value.