SS BLOCK METHODS AND PROCEDURES FOR NR-U
Methods, systems, and apparatuses for use in wireless communication are disclosed. A method of communication on an unlicensed band may include detecting a Synchronization Signal/Physical Broadcast Channel (SS/PBCH) block comprising a demodulation references signal (DMRS), a synchronization signal (SS), and a PBCH payload. A SS/PBCH block index may be obtained from one of the DMRS and the PBCH payload. A cyclic rotation indicator may be obtained from the SS/PBCH block (e.g., from the DMRS, the SS, and/or the PBCH payload). A determination may be made that the cyclic rotation indicator indicates an on state and a time gap may be obtained from one of the DMRS and the PBCH payload, based on the determination. Frame timing may be determined based on the cyclic rotation indicator, the SS/PBCH block index, and the time gap.
1 . A method of wireless communication, the method comprising:
detecting a Synchronization Signal/Physical Broadcast Channel (SS/PBCH) block comprising a demodulation reference signal (DMRS), a synchronization signal (SS), and a PBCH payload;
obtaining a SS/PBCH block index from one of the DMRS or the PBCH payload;
obtaining a cyclic rotation indicator from the DMRS, the SS, or the PBCH payload;
determining that the cyclic rotation indicator indicates an on state and obtaining a time gap from one of the DMRS or the PBCH payload; and
determining frame timing based on the cyclic rotation indicator, the SS/PBCH block index and the time gap.
2 . The method of claim 1 , wherein the time gap is an amount of time between a first rotated burst set and a second rotated burst set.
3 . The method of claim 1 , wherein the time gap is determined based on a successful Listen before Talk (LBT) procedure.
4 . The method of claim 3 , wherein the successful LBT procedure is preceded by a failed LBT procedure.
5 . The method of claim 1 , wherein the SS/PBCH block further comprises at least one of a Primary Synchronization Signal (PSS) or a Secondary Synchronization Signal (SSS).
6 . The method of claim 1 , wherein acquiring the SS/PBCH block index comprises acquiring the SS/PBCH block index from both the DMRS and the PBCH payload.
7 . The method of claim 1 , wherein determining frame timing further comprises determining an offset.
8 . The method of claim 1 , wherein the cyclic rotation indicator comprises one of a one bit indication or a two bit indication.
9 . The method of claim 1 , further comprising cyclically wrapping a portion of the SS/PBCH block based on the cyclic rotation indicator.
10 . The method of claim 1 , wherein determining frame timing is further based on a fixed time duration.
11 . A wireless transmit/receive unit (WTRU) comprising:
an antenna; and
a processor operatively coupled to the antenna, the processor configured to:
detect a Synchronization Signal/Physical Broadcast Channel (SS/PBCH) block comprising a demodulation reference signal (DMRS), a synchronization signal (SS), and a PBCH payload;
obtain a SS/PBCH block index from one of the DMRS or the PBCH payload;
obtain a cyclic rotation indicator from the DMRS, the SS, or the PBCH payload;
determine that the cyclic rotation indicator indicates an on state and obtain a time gap from one of the DMRS or the PBCH payload; and
determine frame timing based on the cyclic rotation indicator, the SS/PBCH block index and the time gap.
12 . The WTRU of claim 11 , wherein the time gap is an amount of time between a first and a second rotated burst set.
13 . The WTRU of claim 11 , wherein the time gap is determined based on a successful Listen before Talk (LBT) procedure.
14 . The WTRU of claim 13 , wherein the successful LBT procedure is preceded by a failed LBT procedure.
15 . The WTRU of claim 11 , wherein the frame timing further comprises an offset.
16 . The WTRU of claim 11 , wherein the cyclic rotation indicator comprises one of a one bit indication and a two bit indication.
17 . The WTRU of claim 11 , further comprising cyclically wrapping a portion of the SS/PBCH block based on the cyclic rotation indicator.
18 . The WTRU of claim 11 , wherein the frame timing is further based on a fixed time duration.
19 . A method of wireless communication, the method comprising:
detecting a Synchronization Signal/Physical Broadcast Channel (SS/PBCH) block comprising a demodulation references signal (DMRS), a synchronization signal (SS) and a PBCH payload;
obtaining a SS/PBCH block index from one of the DMRS or the PBCH payload;
obtaining a cyclic rotation indicator from the DMRS, the SS, or the PBCH payload;
determining that the cyclic rotation indicator indicates an off state; and
determining frame timing based on the SS/PBCH block index based on determining that the cyclic rotation indicator indicates the off state.
20 . The method of claim 19 , wherein the frame timing is further based on a fixed time duration.