Feedback signaling error detection and checking in MIMO wireless communication systems
A method of feedback in a wireless transmit receive unit includes providing a precoding matrix index (PMI), error checking the (PMI) to produce an error check (EC) bit, coding the PMI and the EC bit and transmitting the coded PMI and EC bit.
1. A method implemented in a wireless transmit receive unit (WTRU), the method comprising:
the WTRU generating feedback bits, wherein the feedback bits comprise one or more of a precoding matrix index (PMI) or a channel quality index (CQI);
the WTRU selecting a number of cyclic redundancy check (CRC) bits to attach to the feedback bits based on the number of feedback bits to be encoded;
the WTRU selecting a type of channel coding scheme to apply to the feedback bits and the selected number of CRC bits based on the number of feedback bits to be encoded;
the WTRU encoding the feedback bits and the selected number of CRC bits using the selected type of channel coding scheme; and
the WTRU transmitting the encoded feedback bits.
2. The method as in claim 1 , wherein the encoded feedback bits are transmitted over a data-type channel.
3. The method as in claim 2 , wherein the encoded feedback bits are transmitted over the data-type channel with turbo coded user data bits.
4. The method as in claim 3 , wherein the data-type channel is a physical uplink shared channel (PUSCH).
5. The method as in claim 4 , further comprising the WTRU transmitting second encoded feedback bits, wherein the second encoded feedback bits are transmitted over a physical uplink control channel (PUCCH).
6. The method as in claim 5 , wherein the second encoded feedback bits are encoded using a different type of channel coding scheme than the type of channel coding scheme selected for the feedback bits.
7. The method as in claim 1 , wherein the number of cyclic redundancy check (CRC) selected for attachment to the feedback bits is 16.
8. The method as in claim 1 , wherein the number of cyclic redundancy check (CRC) selected for attachment to the feedback bits is zero.
9. A wireless transmit receive unit (WTRU), the WTRU comprising circuitry configured to:
generate feedback bits, wherein the feedback bits comprise one or more of a precoding matrix index (PMI) or a channel quality index (CQI);
select a number of cyclic redundancy check (CRC) bits to attach to the feedback bits based on the number of feedback bits to be encoded;
select a type of channel coding scheme to apply to the feedback bits and the selected number of CRC bits based on the number of feedback bits to be encoded;
encode the feedback bits and the selected number of CRC bits using the selected type of channel coding scheme; and
transmit the encoded feedback bits.
10. The WTRU as in claim 9 , wherein the selected type of channel coding scheme comprises a convolutional coding scheme.
11. The WTRU as in claim 9 , wherein the selected type of channel coding scheme comprises a block coding scheme.
12. The WTRU as in claim 9 , wherein the processor is configured to transmit a rank indicator with the encoded feedback bits.
13. The WTRU as in claim 12 , wherein the processor is configured to transmit a hybrid automatic repeat request (HARQ) acknowledgement/negative acknowledgment (ACK/NACK) with the encoded feedback signal.
14. The WTRU as in claim 9 , wherein the number of cyclic redundancy check (CRC) selected for attachment to the feedback bits is 24.
15. The WTRU as in claim 9 , wherein the number of cyclic redundancy check (CRC) selected for attachment to the feedback bits is zero.
16. The WTRU as in claim 9 , wherein the processor is further configured to receive a precoding validation message in response to transmitting the feedback bits.
17. The WTRU as in claim 9 , wherein the encoded feedback bits are transmitted over a physical uplink shared channel (PUSCH) with turbo coded user data bits.