DIRECT SEQUENCE CODE DIVISION MULTIPLE ACCESS RECEIVER HAVING PSEUDO NOISE CODE ACQUIRING DEVICE

摘要

PURPOSE: A direct sequence(DS) code division multiple access(CDMA) receiver having a pseudo noise(PN) code acquiring device, is provided to group a number K of PN codes generated when a part correlation value of a received signal and a PN code to acquire a PN code included in the received signal according to a predetermined rule, and to determine one of the K PN codes as a reference code, so as to acquire a PN code by adding the multiplication of the received signal and the reference code according to groups and sharing the added values. CONSTITUTION: A pseudo noise(PN) code generator(500) generates a number K of PN codes having mutually different phases for one data received at a chip rate. A code synchronization circuit(510) by code grouping acquires PN codes included in a received signal, from a correlation value between the codes generated from the PN code generator for an N-bits chip duration time and the received signal. And the code synchronization circuit(510) regulates the phases of the acquired PN codes to match synchronization. A de-spreading circuit(520) de-spreads received signals from synchronization-regulated PN codes in the code synchronization circuit(510). A demodulator(530) demodulates the de-spread signals, corresponding to a modulation system of a transmission party. A code acquisition circuit(511) groups K-bits codes which can be generated in the PN code generator(500) according to a predetermined rule, and calculates a sub-sum for received signal according to a group including the generated codes. And the code acquisition circuit(511) shares the sub-sum to calculate K correlation values, and decides a PN code having a correlation value bigger than a predetermined critical value as a PN code of the received signal. A code tracking circuit(512) relates the phase of the decided PN code, to match synchronization with the received signal.