Patent ID: 6788732
Filing Date: 2004-09-07
Classification: H04B,H04J,H04W

Abstract:
A device for receiving a channel signal for a mobile station in a code division multiple access (CDMA) communication system which includes a first chip rate being multiple times a second chip rate, a first frame with a duration of a spreading sequence having the second chip rate and a second frame whose frame length is multiple times a length of the first frame, in order to receive a spread signal using a spreading code having the first chip rate, which inverts its sign at every other first frame duration, the device comprising:a despreader for despreading the spread signal with a spreading sequence having the first chip rate; an orthogonal demodulator for orthogonally demodulating a pilot channel signal from the despread signal; a decider for examining the pilot channel signal to determine whether the pilot channel signal has varied in sign, and upon detection of variation in sign of the pilot channel signal, deciding a boundary of the first frame; and a sync channel receiver for determining a boundary of the first frame for the sync channel according to an output of the decider and detecting sync bits for predetermined positions of the first frame to acquire synchronization of the second frame.