METHOD AND APPARATUS FOR ACCESSING AN UPLINK RANDOM ACCESS CHANNEL IN A SINGLE CARRIER FREQUENCY DIVISION MULTIPLE ACCESS SYSTEM

摘要

A METHOD AND APPARATUS FOR ACCESSING A CONTENTION-BASED UPLINK RANDOM ACCESS CHANNEL (RACH) IN A SINGLE CARRIER FREQUENCY DIVISION MULTIPLE ACCESS (SC-FDMA) SYSTEM ARE DISCLOSED. A WIRELESS TRANSMIT/RECEIVE UNIT (WTRU) RANDOMLY SELECTS O A RACH SUBCHANNEL AND A SIGNATURE AMONG A PLURALITY OF AVAILABLE RACH SUBCHANNELS AND SIGNATURES. THE WTRU (500) TRANSMITS A PREAMBLE USING THE SELECTED SIGNATURE VIA THE SELECTED RACH SUBCHANNEL AT A PREDETERMINED OR COMPUTED TRANSMISSION POWER. A BASE STATION (600) MONITORS THE RACH TO DETECT THE PREAMBLE AND SENDS AN ACQUISITION INDICATOR (AI) TO THE WTRU (500) WHEN A SIGNATURE IS DETECTED ON THE RACH. WHEN RECEIVING A POSITIVE ACKNOWLEDGEMENT, THE WTRU (500) SENDS A MESSAGE PART TO THE BASE STATION (600). IF RECEIVING A NEGATIVE ACKNOWLEDGEMENT OR NO RESPONSE, THE WTRU (500) RETRANSMITS THE PREAMBLE. (THE MOST ILLUSTRATIVE DRAWING IS