Fast uplink response to downlink shared channel transmission without a dedicated uplink channel
A method and apparatus for uplink transmission over a non-contentious shared feedback channel are disclosed, wherein the parameters of the uplink transmission are determined by the parameters of a downlink transmission. A new uplink channel, called a physical shared uplink feedback channel (PSUFCH) is used for uplink transmission such as feedback information in response to a downlink transmission on a fast shared data channel. The content of the feedback information may be general, e.g. an ACK/NACK or a channel quality indicator (CQI). The PSUFCH is transmitted using power ramping that terminates upon reception of a downlink ACK (DLACK) from a Node-B. No ambiguity resolution is required due to the non-contentious and deterministic mapping of the uplink channel resources.
1. A wireless transmit/receive unit (WTRU) comprising:
a processor and a transmitter configured to transmit control information on a physical uplink channel;
wherein in response to a receiver receiving a transmission for the WTRU in a downlink shared channel in a first transmission time interval (TTI), the processor and the transmitter are configured to transmit on the physical uplink channel in a second TTI to indicate an acknowledgement or a negative acknowledgement;
wherein the processor and the transmitter are configured to transmit channel quality information periodically in TTIs, as periodic TTIs, on the physical uplink channel, wherein the channel quality information includes a delta channel quality information value;
wherein in response to the second TTI overlapping with one of the periodic TTIs, as an overlapping TTI, the processor and transmitter are configured to selectively include or drop an indication of the channel quality information in the overlapping TTI on the physical uplink channel based on predefined rules established by a higher layer;
wherein in response to the second TTI not overlapping with one of the periodic TTIs of the channel quality information, the processor and the transmitter transmit an indication of the acknowledgement or negative acknowledgement and not an indication of the channel quality information on the physical uplink channel; and
wherein the physical uplink channel is not a random access channel.
2. The WTRU of claim 1 wherein the physical uplink channel is shared by a plurality of WTRUs.
3. The WTRU of claim 1 wherein the processor and the transmitter are further configured to transmit in a TTI an indication of a request for uplink bandwidth on the physical uplink channel.
4. The WTRU of claim 3 wherein the processor and the transmitter are further configured in a TTI to not transmit on the physical uplink channel in response to not sending an indication of an acknowledgement, a negative acknowledgement, channel quality information or the request for uplink bandwidth.
5. The WTRU of claim 1 wherein the transmissions on the physical uplink channel have a varying number of bits.
6. The WTRU of claim 1 wherein the transmissions on the physical uplink channel have a plurality of formats having a varying number of bits.
7. The WTRU of claim 1 wherein the receiver and the processor are configured to receive physical channel resource parameters for the physical uplink channel transmissions.
8. A method comprising:
in response to receiving a transmission for a wireless transmit/receive unit (WTRU) in a downlink shared channel in a first transmission time interval (TTI), transmitting, by the WTRU, on a physical uplink channel in a second TTI to indicate an acknowledgement or a negative acknowledgement;
transmitting channel quality information periodically in TTIs, as periodic TTIs, on the physical uplink channel, wherein the channel quality information includes a delta channel quality information value;
wherein in response to the second TTI overlapping with one of the periodic TTIs, as an overlapping TTI, selectively including or dropping an indication of the channel quality information in the overlapping TTI on the physical uplink channel based on predefined rules established by a higher layer;
wherein in response to the second TTI not overlapping with one of the periodic TTIs of the channel quality information, transmitting, by the WTRU, an indication of the acknowledgement or negative acknowledgement and not the indication of the channel quality information; and
wherein the physical uplink channel is not a random access channel.
9. The method of claim 8 wherein the physical uplink channel is shared by a plurality of WTRUs.
10. The method of claim 8 further comprising transmitting in a TTI an indication of a request for uplink bandwidth on the physical uplink channel.
11. The method of claim 10 wherein in response to not sending an indication of an acknowledgement, a negative acknowledgement, channel quality information or the request for uplink bandwidth, not transmitting in a TTI by the WTRU on the physical uplink channel.
12. The method of claim 8 wherein transmissions on the physical uplink channel have a varying number of bits.
13. The method of claim 8 wherein transmissions on the physical uplink channel have a plurality of formats having a varying number of bits.
14. The method of claim 8 further comprising receiving by the WTRU physical channel resource parameters for physical uplink channel transmissions.
15. The WTRU of claim 1 wherein the channel quality information is transmitted based on predefined rules which are one of: (1) rules that are not associated with data transmission to the WTRU; or (2) rules associated with statistics of the data sent to the WTRU.
16. The WTRU of claim 15 wherein responsive to selection of one of the predefined rules, a format of the channel quality information transmitted or a characteristic of the channel quality information transmitted is adjusted.
17. The method of claim 8 further comprising selecting one of the predefined rules from the group consisting of: (1) rules that are not associated with data transmission to the WTRU; or (2) rules associated with statistics of the data sent to the WTRU.
18. The method of claim 8 wherein responsive to selection of one of the predefined rules, adjusting a format of the channel quality information transmitted or adjusting a characteristic of the channel quality information transmitted.