Patent ID: 6700925
Filing Date: 2004-03-02
Classification: G06F,H04B

Abstract:
An apparatus for detecting a correlation of samples with a spread code, said samples being obtained by sampling a spectrum spread signal in a range of one symbol period with a oversampling rate which is N-fold of a chip rate, wherein N is an integer larger than zero, said spread code being of LÃ—M period per symbol, wherein L and M are integers larger than one, said spectrum spread signal having been spread in spectrum by said spread code signal, said apparatus comprising:an L-chip accumulator which inputs said samples to generate and output an intermediate correlation signal of a bit width of W, wherein W is an integer larger than one, Mâˆ’1 memories, each of which has a data width of 2W bits and (LÃ—N)/2 addresses and stores LÃ—N samples of said intermediate correlation signal while combining two intermediate correlation signals as one pair; an adder which has M input terminals and inputs through one of said M input terminals thereof, said intermediate correlation signal which is outputted from said L-chip accumulator and inputs through the others of said M input terminals thereof said intermediate correlation signal which is outputted from a corresponding memory among said Mâˆ’1 memories; and a controller which supplies said intermediate correlation signal outputted from said L-chip accumulator to said Mâˆ’1memories in rotation with a unit of LÃ—N samples, and cyclically reads each of the Mâˆ’1 memories to read and supply to each of the others of said M input terminals of said adder, said intermediate correlation signal which has been stored in each of said Mâˆ’1 memories; wherein an output of said adder is outputted as an correlation signal outputted from the apparatus.