User equipment and method for resource allocation

A user equipment comprising:

• a transmitter configured to transmit a preamble;
• a receiver configured to receive a signal including a first indicator and one of a plurality of second indicators on Acquisition Indicator Channel (AICH), the first indicator corresponding to a first signature, the plurality of second indicators corresponding to a plurality of second signatures respectively;
• a processor comprising hardware configured to:
• detect negative acknowledgment (NACK) in a case where the first indicator is set to −1 and all of the plurality of second indicators are set to 0, and
• detect an Enhanced Dedicated Channel (E-DCH) resource by using at least one of the plurality of second indicators in a case where the first indicator is set to −1 and the at least one of the plurality of second indicators is set to −1 or +1,
• the transmitter configured to:
• perform a preamble retransmission in a case where the first indicator is set to −1 and all of the plurality of second indicators are set to 0, and
• transmit data using the E-DCH resource in a case where the first indicator is set to −1 and the at least one of the plurality of second indicators is set to −1 or +1.