Fast uplink response to downlink shared channel transmission without a dedicated uplink channel

A wireless transmit/receive unit (WTRU) for uplink transmission, the WTRU comprising:

• a transceiver configured to receive a downlink transmission via a high speed downlink shared channel and transmit an uplink transmission via a physical shared uplink feedback channel (PSUFCH);
• and
• a processor configured to determine at least one uplink transmission parameter based on at least one downlink parameter used for the downlink transmission.

A method for uplink transmission, the method comprising:

• receiving a downlink transmission via a high speed downlink shared channel;
• and
• transmitting an uplink transmission via a physical shared uplink feedback channel (PSUFCH), wherein the uplink transmission comprises a one-bit response and a selected signature sequence.

A method for uplink transmission, the method comprising:

• receiving a downlink transmission via a high speed downlink shared channel;
• and
• transmitting an uplink transmission via a physical shared uplink feedback channel (PSUFCH), wherein the uplink transmission comprises a selected signature sequence, and the presence of the transmission represents explicitly transmitted data.