Short physical uplink control channel (sPUCCH) structure
A wireless transmit/receive unit (WTRU) may modulate, based on a number of uplink control bits, a first sequence or the first sequence and a second sequence. The WTRU may spread the first sequence and the second sequence with a complementary sequence pair, concatenate parts of the first sequence and the second sequence in interlaced resource blocks (RBs), and perform an inverse discrete Fourier transform (IDFT) on the interlaced parts. The WTRU may transmit on a physical uplink control channel (PUCCH) a signal outputted by the IDFT.
1. A method performed by a wireless transmit/receive unit (WTRU), the method comprising:
transmitting a first cyclically shifted version of a base sequence in a first resource block (RB) of an interlace of a plurality of RBs of a physical uplink control channel (PUCCH), the first cyclically shifted version of the base sequence having a first cyclic shift which is a function of an index of the first RB; and
transmitting a second cyclically shifted version of the base sequence in a second RB of the interlace, the second cyclically shifted version of the base sequence having a second cyclic shift which is a function of an index of the second RB.
2. The method of claim 1 , wherein the PUCCH is transmitted over an unlicensed carrier.
3. The method of claim 1 , wherein the plurality of RBs of the interlace are distributed evenly over a channel bandwidth.
4. The method of claim 3 , wherein the distribution is achieved using orthogonal spreading sequences.
5. The method of claim 1 , wherein, after the first and second base sequences being cyclically shifted, the first and second RBs are mapped to the interlace using a block-interleaved frequency division multiple access (B-IFDMA) waveform.
6. A wireless transmit/receive unit (WTRU) comprising:
a transmitter configured to transmit a first cyclically shifted version of a base sequence in a first resource block (RB) of an interlace of a plurality of RBs of a physical uplink control channel (PUCCH), the first cyclically shifted version of the base sequence having a first cyclic shift which is a function of an index of the first RB; and
the transmitter configured to transmit a second cyclically shifted version of the base sequence in a second RB of the interlace, the second cyclically shifted version of the base sequence having a second cyclic shift which is a function of an index of the second RB.
7. The WTRU of claim 6 , wherein the PUCCH is transmitted over an unlicensed carrier.
8. The WTRU of claim 6 , wherein the plurality of RBs of the interlace are distributed evenly over a channel bandwidth.
9. The WTRU of claim 8 , wherein the distribution is achieved using orthogonal spreading sequences.
10. The WTRU of claim 6 , wherein the first and second cyclically shifted base sequences of the first and second RBs are mapped to the interlace using a block-interleaved frequency division multiple access (B-IFDMA) waveform.
11. A method performed by a wireless transmit/receive unit (WTRU), the method comprising:
receiving a downlink transmission;
transmitting a first physical uplink control channel (PUCCH) signal in a first resource block (RB) of an interlace of a plurality of RBs, the first PUCCH signal comprising a base sequence having a cyclic shift which is a function of an index of the first RB; and
transmitting a second PUCCH signal in a second RB of the interlace of the plurality of RBs, the second PUCCH signal comprising the base sequence having a cyclic shift which is a function of an index of the second RB, wherein the cyclic shift of the first RB is different than the cyclic shift of the second RB,
wherein the base sequence of the first PUCCH signal and the second PUCCH signal comprise information indicating either an acknowledgement (ACK) or a negative ACK (NACK) of the downlink transmission.
12. The method of claim 11 , wherein the first PUCCH signal and the second PUCCH signal are transmitted over an unlicensed carrier.
13. The method of claim 11 , wherein the plurality of RBs of the interlace are distributed evenly over a channel bandwidth.
14. The method of claim 13 , wherein the distribution is achieved using orthogonal spreading sequences.
15. The method of claim 11 , wherein, after the base sequence being cyclically shifted, the first and second RBs are mapped to the interlace using a block-interleaved frequency division multiple access (B-IFDMA) waveform.