SYSTEM FOR CONTROLLING TRANSMISSION POWER RAMP-UP IN WIRELESS CDMA SYSTEM BY USING SHORT CODES

摘要

PROBLEM TO BE SOLVED: To provide an improved method for controlling transmission power ramp-up during establishment of a communication channel between a subscriber unit and a base station in a wireless CDMA communication system.SOLUTION: A system and method for controlling transmission power during establishment of a channel in a CDMA communication system utilize the transmission of a short code from a subscriber unit to a base station during initial transmission power ramp-up. The short code is a sequence for detection by the base station, which has a much shorter period than a conventional spreading code. The transmission power ramp-up starts from a transmission power level that is ensured to be lower than the required transmission power level for detection by the base station. The subscriber unit quickly increases transmission power while repeatedly transmitting the short code until the signal is detected by the base station. Once the base station detects the short code, it sends an instruction to the subscriber unit to cease increasing transmission power.