Method and apparatus for sending feedback for a downlink shared service transmitted to a plurality of wireless transmit/receive units
A wireless transmit/receive units (WTRUs) receives a downlink transmission from a Node-B and decodes the downlink transmission. If the decoding is not successful, the WTRU sends a pre-defined burst signifying a negative acknowledgement (NACK) to the Node-B via a contention-based shared feedback channel. The pre-defined burst may be sent only once without requiring an acknowledgement. The Node-B calibrates a downlink transmit power so that the downlink transmission is transmitted to the WTRUs with a high likelihood. The Node-B may send a downlink transmission including multiple data streams processed using different modulation and coding schemes so that a WTRU having a high signal quality decodes all data streams while a WTRU having a low signal quality decodes less than all data streams. The Node-B sends a channel quality indicator (CQI) threshold so that each WTRU determines a data stream to report feedback based on the CQI threshold and a measured CQI.
1. A method for sending feedback in wireless communication, comprising:
receiving, by a wireless transmit/receive unit (WTRU), a message via radio resource control (RRC) signaling, wherein the message indicates a configuration for transmissions by the WTRU on a physical uplink channel, wherein different portions of the physical uplink channel are used to transmit different types of feedback information;
transmitting, by the WTRU, a first feedback information on the physical uplink channel, wherein the first feedback information includes acknowledgement feedback information; and
transmitting, by the WTRU, a second feedback information on the physical uplink channel, wherein the second feedback information includes a channel quality indicator,
wherein the acknowledgement feedback information is transmitted on a first frequency resource associated with the physical uplink channel and the channel quality indicator is transmitted on a second frequency resource associated with the physical uplink channel.
2. The method of claim 1 , wherein the first frequency resource and the second frequency resource are different subcarriers.
3. The method of claim 1 , wherein the acknowledgement feedback information is modulated using on-off keying.
4. The method of claim 1 , further comprising:
determining a number of streams to report channel quality indicator information using a threshold.
5. The method of claim 1 , further comprising:
receiving a power command on a downlink control channel; and
setting a transmission power level for the physical uplink channel in response to the received power command.
6. The method of claim 5 , further comprising:
receiving an offset value; and
transmitting on the physical uplink channel at a transmission power level determined based on the offset value.
7. A wireless transmit/receive unit (WTRU) for sending feedback in wireless communication, the WTRU comprising:
a processor configured to:
receive a message via radio resource control (RRC) signaling, wherein the message indicates a configuration for transmissions by the WTRU on a physical uplink channel, wherein different portions of the physical uplink channel are used to transmit different types of feedback information,
transmit a first feedback information on the physical uplink channel, wherein the first feedback information includes acknowledgement feedback information, and
transmit a second feedback information on the physical uplink channel, wherein the second feedback information includes a channel quality indicator,
wherein the processor is configured to transmit the acknowledgement feedback information on a first frequency resource associated with the physical uplink channel and the channel quality indicator on a second frequency resource associated with the physical uplink channel.
8. The WTRU of claim 7 , wherein the first frequency resource and the second frequency resource are different subcarriers.
9. The WTRU of claim 7 , wherein the acknowledgement feedback information is modulated using on-off keying.
10. The WTRU of claim 7 , wherein the processor is configured to determine a number of streams to report channel quality indicator information using a threshold.
11. The WTRU of claim 7 , wherein the processor is configured to receive a power command on a downlink control channel and set a transmission power level for the physical uplink channel in response to the received power command.
12. The WTRU of claim 11 , wherein the processor is configured receive an offset value, and transmit on the physical uplink channel at a transmission power level determined based on the offset value.
13. A network device for receiving feedback from a wireless transmit/receive unit (WTRU), the network device comprising:
a processor configured to:
transmit a message via radio resource control (RRC) signaling to the WTRU, wherein the message indicates a configuration for transmissions by the WTRU on a physical uplink channel, wherein different portions of the physical uplink channel are used to receive different types of feedback information, and
receive a first feedback information on the physical uplink channel from the WTRU, wherein the first feedback information includes acknowledgement feedback information, and
receive a second feedback information on the physical uplink channel from the WTRU, wherein the second feedback information includes a channel quality indicator,
wherein the processor is configured to receive the acknowledgement feedback information on a first frequency resource associated with the physical uplink channel and the channel quality indicator on a second frequency resource associated with the physical uplink channel.
14. The network device of claim 13 , wherein the first frequency resource and the second frequency resource are different subcarriers.
15. The network device of claim 13 , wherein the acknowledgement feedback information is modulated using on-off keying.
16. The network device of claim 13 , wherein the processor is configured to transmit a power command on a downlink control channel to set a transmission power level for the physical uplink channel.
17. The network device of claim 16 , wherein the processor is configured to transmit an offset value to adjust the transmission power level for the physical uplink channel.
18. The method of claim 1 , wherein the feedback information is transmitted using a quandrature phase shifting key (QPSK) or a binary phase shifting key (BPSK).
19. The method of claim 1 , wherein the first feedback information is transmitted on the physical uplink channel without an explicit transmission of a data type indicator that identifies the acknowledgement feedback information, and wherein the second feedback information is transmitted on the physical uplink channel without an explicit transmission of a data type indicator that identifies the channel quality indicator.
20. The WTRU of claim 7 , wherein the processor is configured to transmit the feedback information using a quandrature phase shifting key (QPSK) or a binary phase shifting key (BPSK).
21. The WTRU of claim 7 , wherein the processor is configured to transmit the first feedback information on the physical uplink channel without an explicit transmission of a data type indicator that identifies the acknowledgement feedback information, and wherein the processor is configured to transmit the second feedback information on the physical uplink channel without an explicit transmission of a data type indicator that identifies the channel quality indicator.
22. The network device of claim 13 , wherein the processor is configured to receive the feedback information via a quandrature phase shifting key (QPSK) or a binary phase shifting key (BPSK).
23. The network device of claim 13 , wherein the processor is configured to receive the first feedback information on the physical uplink channel without an explicit data type indicator that identifies the acknowledgement feedback information, and wherein the processor is configured to receive the second feedback information on the physical uplink channel without an explicit data type indicator that identifies the channel quality indicator.