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;
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 attaching the selected number of CRC bits to the feedback bits;
the WTRU applying a channel coding scheme to the feedback bits and to the selected number of CRC bits; and
the WTRU transmitting the channel coded feedback and CRC bits.
2. The method as in claim 1 , wherein the feedback bits comprise one or more of a precoding matrix index (PMI), a channel quality index (CQI), a rank indicator (RI), or hybrid automatic repeat request (HARM) feedback.
3. The method as in claim 1 , wherein the channel coded feedback and CRC bits are transmitted over a physical uplink control channel (PUCCH).
4. The method as in claim 1 , wherein the channel coded feedback and CRC bits are transmitted over a physical uplink shared channel (PUSCH).
5. The method as in claim 1 , further comprising:
the WTRU generating second feedback bits;
the WTRU grouping at least a first portion of the second feedback bits into a first feedback group and at least a second portion of the second feedback bits into a second feedback group;
the WTRU applying first CRC bits to the first feedback group and second CRC bits to the second feedback group;
the WTRU applying the channel coding scheme to the first feedback group and the first CRC bits;
the WTRU separately applying the channel coding scheme to the second feedback group and the second CRC bits;
the WTRU transmitting the channel coded first feedback group and first CRC bits; and
the WTRU transmitting the separately channel coded second feedback group and second CRC bits.
6. The method as in claim 1 , wherein a second channel coding scheme is used to encode user data bits.
7. The method as in claim 1 , wherein the number of CRC bits selected for attachment to the feedback bits is 16.
8. The method as in claim 1 , wherein the channel coding scheme is selected based on the number of feedback bits to be encoded.
9. A wireless transmit receive unit (WTRU), the WTRU comprising a processor configured to:
generate feedback bits;
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;
attach the selected number of CRC bits to the feedback bits;
apply a channel coding scheme to the feedback bits and to the selected number of CRC bits; and
transmit the channel coded feedback and CRC bits.
10. The WTRU as in claim 9 , wherein the feedback bits comprise one or more of a precoding matrix index (PMI), a channel quality index (CQI), a rank indicator (RI), or hybrid automatic repeat request (HARM) feedback.
11. The WTRU as in claim 9 , wherein the channel coded feedback and CRC bits are transmitted over a physical uplink control channel (PUCCH).
12. The WTRU as in claim 9 , wherein the channel coded feedback and CRC bits are transmitted over a physical uplink shared channel (PUSCH).
13. The WTRU as in claim 9 , wherein the processor is configured to: generate a second feedback bits; group at least a first portion of the second feedback bits into a first feedback group and at least a second portion of the second feedback bits into a second feedback group; apply first CRC bits to the first feedback group and second CRC bits to the second feedback group; apply the channel coding scheme to the first feedback group and the first CRC bits; separately apply the channel coding scheme to the second feedback group and the second CRC bits; transmit the channel coded first feedback group and first CRC bits; and transmit the separately channel coded second feedback group and second CRC bits.
14. The WTRU as in claim 9 , wherein a second channel coding scheme is used to encode user data bits.
15. The WTRU as in claim 9 , wherein the number of cyclic redundancy check (CRC) bits selected for attachment to the feedback bits is 24.
16. The WTRU as in claim 9 , wherein the channel coding scheme is selected based on the number of feedback bits to be encoded.