Control method of searching neighboring cells, mobile station, and mobile, communication system

• Main Authors: YUNOKI KAZUFUMI, HIGASHI AKIHIRO, ONOE SEIZO, ISHIKAWA YOSHIHIRO
• Format: Patent
• Language: English
• Published: 15.04.2004
• Edition: 7
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; TRANSMISSION; WIRELESS COMMUNICATIONS NETWORKS

A control method of searching for a neighboring cell of a mobile station communicating with a base-station is provided in a direct sequence CDMA mobile communication system which transmits information by carrying out double modulation using a first spreading code group and a second spreading code. The first spreading code group includes spreading codes that have a same repetition period as an information symbol period and are used in common by the base stations, and the second spreading code has a repetition period longer than the information symbol period. The base stations are assigned different second spreading codes. The control method stores at least one second spreading code and its phase into a first table, which second spreading code corresponds to a perch channel whose second spreading code and phase are known; stores a second spreading code used by a neighboring base station into a second table; searches for a perch channel whose second spreading code and phase are unknown; and searches for a perch channel whose second spreading code and phase are known. The neighboring cell search method can save the power consumption and time required for the mobile station to carry out the cell search with preventing an increase in the total cost of the system.