Efficient utilization of SSBS in new radio systems
Methods and an apparatus for performing synchronization in New Radio (NR) systems are disclosed. A frequency band may be determined and may correspond to a WTRU. On a condition that the operational frequency band is a lower frequency, a synchronization signal block (SSB) index may be implicitly. On a condition that the operational frequency band is a higher frequency, an SSB index may be determined based on a hybrid method which includes determining the SSB index using both an implicit and an explicit method. A configuration of actually transmitted SSBs may be determined using a multi-level two stage compressed indication where SSB groups are determined based on a coarse indicator and actually transmitted SSBs with the SSB groups are determined based on a fine indicator.
1. A user equipment (UE) comprising:
a transceiver; and
circuitry configured to:
receive one or more synchronization signal blocks (SSBs);
determine an operational frequency band;
determine a value L corresponding to the operational frequency band, the value L indicating a maximum number of SSBs in a synchronization signal (SS) burst;
on a condition that the value L is 4 or 8, determine an SSB index based on a physical broadcast channel (PBCH) demodulation reference signal (DMRS) sequence; and
on a condition that the value L is 64, determine the SSB index using both of the PBCH DMRS sequence and a PBCH payload,
wherein, on the condition that the value L is 64, the SSB index consists of least significant bits (LSBs), and most significant bits (MSBs),
wherein the LSBs for the SSB index is determined based on the PBCH DMRS sequence, and
wherein the MSBs for the SSB index is determined based on the PBCH payload.
2. The UE according to claim 1 , wherein, on the condition that the value L is 64, the MSBs for the SSB index are interleaved, coded and rate-matched along with other bits of the PBCH.
3. A method performed by a user equipment (UE), the method comprising:
receiving one or more synchronization signal blocks (SSBs);
determining an operational frequency band;
determining a value L corresponding to the operational frequency band, the value L indicating a maximum number of SSBs in a synchronization signal (SS) burst;
on a condition that the value L is 4 or 8, determining an SSB index based on a physical broadcast channel (PBCH) demodulation reference signal (DMRS) sequence; and
on a condition that the value L is 64, determining the SSB index using both of the PBCH DMRS sequence and a PBCH payload,
wherein, on the condition that the value L is 64, the SSB index consists of least significant bits (LSBs), and most significant bits (MSBs),
wherein the LSBs for the SSB index is determined based on the PBCH DMRS sequence, and
wherein the MSBs for the SSB index is determined based on the PBCH payload.
4. The method according to claim 3 , wherein, on the condition that the value L is 64, the MSBs for the SSB index are interleaved, coded and rate-matched along with other bits of the PBCH.
5. A gNodeB (gNB) comprising:
a transceiver; and
circuitry configured to:
perform a time synchronization between the gNB and a User Equipment (UE) by using synchronization signals, the synchronization signals including Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS),
wherein the PSS, the SSS and a Physical Broadcast Channel (PBCH) are included in a Synchronization Signal Block (SSB); and
determine the number of the SSBs in a synchronization signal burst (SS burst),
wherein a frequency band is associated with a value L indicating a maximum number of the SSBs in the SS burst,
wherein, on a condition that the value L is 4 or 8, an SSB index which is index of the SSB is encoded in a PBCH demodulation reference signal (DMRS) sequence,
wherein, on a condition that the value L is 64, the SSB index is encoded in both of the PBCH DMRS sequence and a PBCH payload,
wherein, on the condition that the value L is 64, the SSB index consists of least significant bits (LSBs) and most significant bits (MSBs),
wherein the LSBs for the SSB index is encoded in the PBCH DMRS sequence, and
wherein the MSBs for the SSB index is encoded in the PBCH payload.
6. The gNB according to claim 5 , wherein, on the condition that the value L is 64, the MSBs for the SSB index are interleaved, coded and rate-matched along with other bits of the PBCH.
7. A method performed by a gNodeB (gNB), the method comprising:
performing a time synchronization between the gNB and a User Equipment (UE) by using synchronization signals, the synchronization signals including Primary Synchronization Signal (PSS) and Secondary Synchronization Signal (SSS),
wherein the PSS, the SSS and a Physical Broadcast Channel (PBCH) are included in a Synchronization Signal Block (SSB); and
determining the number of the SSBs in a synchronization signal burst (SS burst),
wherein a frequency band is associated with a value L indicating a maximum number of the SSBs in the SS burst,
wherein, on a condition that the value L is 4 or 8, an SSB index which is index of the SSB is encoded in a PBCH demodulation reference signal (DMRS) sequence,
wherein, on a condition that the value L is 64, the SSB index is encoded in both of the PBCH DMRS sequence and a PBCH payload,
wherein, on the condition that the value L is 64, the SSB index consists of least significant bits (LSBs) and most significant bits (MSBs),
wherein the LSBs for the SSB index is encoded in the PBCH DMRS sequence, and
wherein the MSBs for the SSB index is encoded in the PBCH payload.
8. The method according to claim 7 , wherein, on the condition that the value L is 64, the MSBs for the SSB index are interleaved, coded and rate-matched along with other bits of the PBCH.