초록 ▼

A novel system and method reduces the time required by a base station to re-acquire a fixed subscriber unit in a CDMA communication system by virtually locating of the subscriber units. A base station acquires subscriber units by searching only those code phases concomitant with the largest propagat

A novel system and method reduces the time required by a base station to re-acquire a fixed subscriber unit in a CDMA communication system by virtually locating of the subscriber units. A base station acquires subscriber units by searching only those code phases concomitant with the largest propagation delay possible in the cell, as if all subscriber units were located at the periphery of the cell. A subscriber unit which has never been acquired by the base station varies the delay between the PN code phase of its received and transmitted signals over the range of possible delays in a cell and slowly ramps-up its transmission power until it is acquired by the base station. Upon initial acquisition by the base station, the subscriber unit ceases ramping-up its transmission power, ceases varying the delay and internally stores the final value of the delay in memory. For subsequent re-acquisition, the subscriber unit adds the delay value between the PN code phase of its received and transmitted signals, making the subscriber virtually appear to be at the periphery of the cell. This permits a quick ramp-up of transmission power by the subscriber unit and reduced acquisition time by the base station.

대표청구항 ▼

[ What is claimed is:] [1.] A method for reducing the reacquisition time of a subscriber unit by a base station in a network for communicating between a base station and at least one subscriber unit; the method comprising:transmitting an access signal from a subscriber unit at a predetermined power

[ What is claimed is:] [1.] A method for reducing the reacquisition time of a subscriber unit by a base station in a network for communicating between a base station and at least one subscriber unit; the method comprising:transmitting an access signal from a subscriber unit at a predetermined power transmission level;increasing said predetermined power transmission level until a confirmation signal is received from said base station;detecting said access signal at said base station when a sufficient power level has been achieved;transmitting a confirmation signal from said base station when said access signal has been detected;receiving said confirmation signal at said subscriber unit;ceasing the increase in transmission power from said subscriber unit when said confirmation signal is received;calculating a delay value at said subscriber unit between said access signal and said confirmation signal; andstoring said delay for subsequent subscriber unit reacquisitions.