Patent ID: 6175561
Filing Date: 2001-01-16
Classification: H04B

Abstract:
In a cellular telephone operable in a code division multiple access CDMA cellular telephone communication system, a receiver circuit for determining a timing of a pseudorandom noise PN spreading code of a signal intended for said cellular telephone, said receiver circuit comprising, in combination:a first memory for storing digital samples of said signal at a first rate;at least one PN sequence generator operable to produce at a second rate a replica of said PN spreading code at a plurality of PN chip offsets, said second rate higher in frequency than said first rate;a multiplier operable to multiply at said second rate said signal, read from said first memory, with said replica of said PN spreading code at each of said plurality of PN chip offsets;a summing circuit operable to sum an output of said multiplier to produce correlation results; anda second memory to store correlation results having highest correlation energies.