Method and apparatus for performing an access procedure

Abstract

A base station for controlling transmission power during the establishment of a communication channel utilizes the reception of a short code during initial power ramp-up. The short code is a sequence for detection by the base station which has a much shorter period than a conventional access code. The ramp-up starts from a power level that is lower than the required power level for detection by the base station. The power of the short code is quickly increased until the signal is detected by the base station. Once the base station detects the short code, it transmits an indication that the short code has been detected.

1 . A system comprising:
 a subscriber unit comprising:
 a transmitter configured such that, when the subscriber unit is accessing a wireless code division multiple access (CDMA) network, the transmitter successively sends transmissions having a first plurality of chips until the subscriber unit receives an indication from a base station that the base station has detected at least one of the transmissions; 
 the transmitter further configured such that, subsequent to the subscriber unit receiving the indication, the transmitter sends a transmission having a second plurality of chips; 
 wherein the first plurality of chips and the second plurality of chips are derived from a third plurality of chips; and 
 wherein the first plurality of chips has fewer chips than the second plurality of chips; and 
   a base station comprising:
 circuitry configured to detect the transmissions having a first plurality of chips; and 
 a transmitter configured to transmit the indication on a condition that at least one of the transmissions having a first plurality of chips has been detected by the base station.