Initial synchronization method in code division multiple access

Abstract

An initial synchronization method in a code division multiple access reception system for determining a pseudonoise (PN) code received in the system by receiving a signal corresponding to an interval of the PN code in a window size, determining representative values of corresponding ones of PN code chips in the window, respectively, and determining the representative values as chips of the PN code, comprising the steps of selecting n successive PN code chips having the same offset in each interval of the PN code, deriving mn (m<n) phase differences of the successive PN code chips in each interval of the PN code, and continuously deriving subsequent PN code chips, thereby deriving n PN code chips, and deriving representative values of n chips of the PN code, based on corresponding ones of the PN code chips derived in all intervals of the PN code, respectively, thereby determining the PN code. In order to verify the initial synchronization, a first PN code signal derived in the above procedure is used. A second PN code signal is also used which is derived by shifting offsets p times in each interval of the PN code. For the verification, the second PN code signal is compared with a signal which is obtained by shifting, by p clocks, a seed derived from a generating polynomial of a PN code generator included in the system based on the first PN code signal.