Code division multiple access mobile communication system

• US 20040228316A1
• Filed: 06/18/2004
• Published: 11/18/2004
• Est. Priority Date: 05/13/1998
• Status: Active Grant

• Current Assignee: IPCom GmbH & Co KG
• Original Assignee: Hitachi, Ltd.
• Inventors: Doi, Nobukazu, Yano, Takashi, Suzuki, May
• Granted Patent: US 7,778,310 B2
• Time in Patent Office: Days
• US Class Current: 370/342
• CPC Class Codes: H04B 1/7075 with code phase acquisition
• CPC Class Codes: H04B 1/708 Parallel implementation
• CPC Class Codes: H04B 7/2628 using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA] H04B7/2618 takes precedence
• CPC Class Codes: H04B 7/2668 Arrangements for Wireless Code-Division Multiple Access [CDMA] System Synchronisation, for code acquisition H04B1/7075, for code tracking H04B1/7085
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

In a mobile communication system using a code division multiple access (CDMA) method, spreading code detection and frame/slot timing synchronization (cell search) is conducted by using a long code masked symbol. The spreading factor of the long code masked symbol is set to a value lower than spreading factors of other ordinary symbols. As a result, it becomes possible to reduce the circuit scale and power dissipation of the mobile terminal and raise the speed of cell search.

Claims

1. A slot timing synchronization method in a code division multiple access mobile communication system, said slot timing synchronizing method comprising the steps of:

transmitting from a base station a control signal via perch channels, a first section of one slot of said control signal being spread by a long period code assigned to said base station, a second section of said one slot being spread by a predetermined short period signal; and

in a mobile terminal, despreading said control signal by using said predetermined short period code, and conducting slot timing synchronization by using a correlation value obtained as a result of despreading, a spreading factor of said predetermined short period code being set to a value lower than a spreading factor of the long period code and a short period code spreading said first section.

2-11. -11. (Canceled)