Method and apparatus for acquiring code group in asynchronous wideband code division multiple access system using receiver diversity

An apparatus for acquiring a code group in an asynchronous WCDMA system, comprising:

• a primary synchronization channel search unit for informing a mobile station of a slot start point;
• a 1-1 search unit of a secondary synchronization channel for, if primary synchronization channel slot timing synchronization is achieved, starting correlation operations between some of slots of the secondary synchronization channel, which has been received through a first antenna, and code group candidates, and transmitting information about candidates having values exceeding a predetermined threshold value to a determination unit;
• a 1-2 search unit of the secondary synchronization channel for, if primary synchronization channel slot timing synchronization is achieved, starting correlation operations between some of slots of the secondary synchronization channel, which has been received through a second antenna, and code group candidates, and transmitting information about candidates having values exceeding a predetermined threshold value to a determination unit;
• a determination unit for transmitting the information about the candidates, which has been received from the 1-1 search unit and 1-2 search unit of the secondary synchronization channel, to a second search unit of the secondary synchronization channel;
• and
• the second search unit of the secondary synchronization channel for calculating correlation characteristics based on the information about the candidates received from the determination unit, and selecting a code group candidate having a highest correlation characteristic.

A method of acquiring a code group in an asynchronous WCDMA system, comprising:

• a first step at which a primary synchronization channel search unit achieves primary synchronization channel slot timing synchronization;
• a second step at which, if the primary synchronization channel slot timing synchronization is achieved, a 1-1 search unit of a secondary synchronization channel receives a secondary synchronization channel from a first antenna, starts correlation operations between some of slots of the received channel and code group candidates, and transmits information about candidates having values exceeding a predetermined threshold value to a second search unit of a secondary synchronization channel;
• a third step at which, if the primary synchronization channel slot timing synchronization is achieved, a 1-2 search unit of the secondary synchronization channel receives the secondary synchronization channel from a second antenna, starts correlation operations between some of slots of the received channel and code group candidates, and transmits information about candidates having values exceeding a predetermined threshold value to the second search unit of the secondary synchronization channel;
• and
• a fourth step at which the second search unit of the secondary synchronization channel calculates correlation characteristics based on the information about the candidates, which has been received from the determination unit, and selects a candidate having a highest correlation characteristic.