초록 ▼

A method and system for use in determining the position of a mobile terminal in a CDMA mobile communications system is disclosed, whereby a different than usual spreading code is used when TOA measurements are being performed, but information is allowed to be transmitted while those TOA measurements

A method and system for use in determining the position of a mobile terminal in a CDMA mobile communications system is disclosed, whereby a different than usual spreading code is used when TOA measurements are being performed, but information is allowed to be transmitted while those TOA measurements are being performed. In one embodiment, the length of the different spreading codes used is equal to one symbol length. In a second embodiment, a mobile terminal uses a long spreading code and short spreading code prior to making TOA measurements. When TOA measurements are to be made, the serving base station orders the mobile terminal to change the spreading code by terminating the use of the long code and continuing use of the short code. Alternatively, when the TOA measurements are to be made, the serving base station orders the mobile terminal to substitute a second, predetermined short code for the long code being used, and to continue use of the first short code. The TOA measurements are then performed in at least three base stations, and the position of the mobile terminal is derived from this TOA information. The serving base station then orders the mobile terminal to resume normal operations using the long code.

대표청구항 ▼

[ What is claimed is:] [1.] A method for aiding in a determination of the position of a mobile terminal in a CDMA mobile radio system, comprising the steps of:for measuring an uplink time of arrival, ordering said mobile terminal to switch from spreading with a first short spreading code and a long

[ What is claimed is:] [1.] A method for aiding in a determination of the position of a mobile terminal in a CDMA mobile radio system, comprising the steps of:for measuring an uplink time of arrival, ordering said mobile terminal to switch from spreading with a first short spreading code and a long spreading code to spreading with at least a second short spreading code;receiving in at least three radio base stations a transmitted signal from said mobile terminal including said at least a second short spreading code;measuring said uplink time of arrival for said transmitted signal in said at least three radio base stations, using a correlation with said at least a second short spreading code independently of information conveyed in said transmitted signal; andwherein said at least a second short spreading code is different from said first short spreading code.