Method and apparatus for inter-user equipment coordination signaling
Methods and apparatuses for inter user equipment (UE) coordination signaling. A method of operating a UE includes determining a first set of first sidelink (SL) resources based on SL sensing and resource exclusion; selecting a first one or more SL resources within the first determined set for reservation, transmitting information about the first one or more SL resources, and receiving inter UE co-ordination information indicating whether a SL resource in the first one or more SL resources has a conflict. The method further includes transmitting on one of the first one or more SL resources, when the one SL resource does not have a conflict; and determining a second set of SL resources based on SL sensing and resource exclusion, and selecting a second one or more SL resources within the second set for transmission and reservation, when all of the first one or more SL resources have a conflict.
1. A first user equipment (UE) in a communication system, the first UE comprising:
a processor configured to:
decode a physical sidelink control channel (PSCCH), wherein the PSCCH includes a resource reservation period (P rsvp ) field in units of milliseconds (ms); and
convert P rsvp into P′ rsvp in logical slots,
wherein:
P rsvp is multiplied by a ratio L/T and rounded-up based on a ceiling function to obtain P′ rsvp ,
T is a period in units of ms,
L is a value related to logical slots in a resource pool in the period T, and
L is determined as a number of slots corresponding to bits having value 1 within a bitmap, among a set of slots in the period T excluding at least one non-SL slot, at least one sidelink synchronization signal block (S-SSB) slot, and at least one reserved slot.
2. The first UE of claim 1 , wherein:
the processor is further configured to identify whether a conflict occurs on a first reserved resource for a second UE, and
the conflict occurs on the first reserved resource in response to the first reserved resource being overlapped, in time, with a resource for transmission of the first UE.
3. The first UE of claim 1 , wherein:
the processor is further configured to identify whether a conflict occurs on a first reserved resource for a second UE, and
the conflict occurs on the first reserved resource in response to the first reserved resource being overlapped, in time and frequency, with a second reserved resource for a PSSCH of a third UE.
4. The first UE of claim 3 , wherein a reference signal received power (RSRP) of the third UE is above a RSRP threshold, and
wherein the RSRP threshold depends on a first priority value associated with the first reserved resource and a second priority value associated with the second reserved resource.
5. The first UE of claim 1 , wherein T=10240 ms.
6. The first UE of claim 5 , wherein:
L
=
(
2
μ
×
1
0
2
4
0
-
N
n
o
n
S
L
-
N
S
-
S
S
B
-
N
reserved
)
×
L
bitmap
,
o
n
e
L
bitmap
,
μ; is a sub-carrier spacing configuration,
N nonSL : is a number of non-SL slots in 1024 frames,
N S-SSB : is a number of S-SSB slots in 1024 frames,
N reserved : is a number of reserved slots in 1024 frames,
L bitmap,one : is a number of bits having value 1 in the bitmap associated with the resource pool, and
L bitmap : is a total number of bits in the bitmap associated with the resource pool.
7. The first UE of claim 1 , wherein:
a configured grant period (sl_periodCG) in milliseconds is converted to a period (PeriodicitySL) in logical slots as:
PeriodicitySL
=
⌈
T
′
max
10240
ms
×
sl_periodCG
⌉
8. The first UE of claim 7 , wherein a logical slot for S th sidelink grant for a sidelink configured grant type 1 is determined as:
(sl-ReferenceSlotCG-Type1+sl-TimeOffsetCGType1+S×PeriodicitySL)modulo(T′ max ),
wherein:
sl-ReferenceSlotCG-Type 1: is a reference logical slot determined as sl-ReferenceSlotCG-Type 1=Σ i=0 sl-TimeReferenceSFN_Type1-1 SlotsOfSLResourcePoolinFrame(i),
SlotsOfSLResourcePoolinFrame(i): is a number of slots of a resource pool in a frame with index i,
sl_TimeReferenceSFN_Type1: is a system frame number configured as 0 or 512, and
sl-TimeOffsetCGType1: is a slot offset with respect to the reference logical slot.
9. The first UE of claim 7 , wherein a logical slot for S th sidelink grant for a sidelink configured grant type 2 is determined as:
[sl-StartSlotCG-Type2+S×PeriodicitySL] modulo (T′ max ),
wherein sl-StartSlotCG-Type2 is a logical slot of a first transmission opportunity of PSSCH where the configured sidelink grant was (re-)initialized, and determined as sl-StartSlotCG-Type2=(Σ i=0 SFNstart time-1 SlotsofSLResourcePoolinFrame(i)+slot start time ), SFN start time and slot start time being a subframe number (SFN) and logical slot, respectively, of the first transmission opportunity of PSSCH where the configured sidelink grant was (re-)initialized.
10. A method performed by a first user equipment (UE) in a communication system, the method comprising:
decoding a physical sidelink control channel (PSCCH), wherein the PSCCH includes a resource reservation period (P rsvp ) field in units of milliseconds (ms); and
converting P rsvp into P′ rsvp in logical slots,
wherein:
P rsvp is multiplied by a ratio L/T and rounded-up based on a ceiling function to obtain P′ rsvp ,
T is a period in units of ms,
L is a value related to logical slots in a resource pool in the period T, and
L is determined as a number of slots corresponding to bits having value 1 within a bitmap, among a set of slots in the period T excluding at least one non-SL slot, at least one sidelink synchronization signal block (S-SSB) slot, and at least one reserved slot.
11. The method of claim 10 , further comprising:
identifying whether a conflict occurs on a first reserved resource for a second UE,
wherein the conflict occurs on the first reserved resource in response to the first reserved resource being overlapped, in time, with a resource for transmission of the first UE.
12. The method of claim 10 , further comprising:
identifying whether a conflict occurs on a first reserved resource for a second UE,
wherein the conflict occurs on the first reserved resource in response to the first reserved resource being overlapped, in time and frequency, with a second reserved resource for a PSSCH of a third UE.
13. The method of claim 12 , wherein a reference signal received power (RSRP) of the third UE is above a RSRP threshold, and
wherein the RSRP threshold depends on a first priority value associated with the first reserved resource and a second priority value associated with the second reserved resource.
14. The method of claim 10 , wherein T=10240 ms.
15. The method of claim 14 , wherein:
L
=
(
2
μ
×
1
0
2
4
0
-
N
n
o
n
S
L
-
N
S
-
S
S
B
-
N
reserved
)
×
L
bitmap
,
o
n
e
L
bitmap
μ: is a sub-carrier spacing configuration,
N nonSL : is a number of non-SL slots in 1024 frames,
N S-SSB : is a number of S-SSB slots in 1024 frames,
N reserved : is a number of reserved slots in 1024 frames,
L bitmap,one : is a number of bits having value 1 in the bitmap associated with the resource pool, and
L bitmap : is a total number of bits in the bitmap associated with the resource pool.
16. The method of claim 10 , wherein:
a configured grant period (sl_periodCG) in milliseconds is converted to a period (PeriodicitySL) in logical slots as:
PeriodicitySL
=
⌈
T
max
′
10240
ms
×
sl_periodCG
⌉
17. The method of claim 16 , wherein a logical slot for S th sidelink grant for a sidelink configured grant type 1 is determined as:
(sl-ReferenceSlotCG-Type 1+sl-TimeOffsetCGType1+S×PeriodicitySL) modulo (T′ max ),
wherein:
sl-ReferenceSlotCG-Type1: is a reference logical slot determined as sl-ReferenceSlotCG-Type 1=Σ i=0 sl-TimeReferenceSFN_Typ1-1 SlotsOfSLResourcePoolinFrame(i),
SlotsOfSLResourcePoolinFrame(i): is a number of slots of a resource pool in a frame with index i,
sl_TimeReferenceSFN_Type1: is a system frame number configured as 0 or 512, and
sl-TimeOffsetCGType1: is a slot offset with respect to the reference logical slot.
18. The method of claim 16 , wherein a logical slot for S th sidelink grant for a sidelink configured grant type 2 is determined as:
[sl-StartSlotCG-Type2+S×PeriodicitySL] modulo (T′ max ),
wherein sl-StartSlotCG-Type2 is a logical slot of a first transmission opportunity of PSSCH where the configured sidelink grant was (re-)initialized, and determined as sl-StartSlotCG-Type2=(Σ i=0 SFNstart time-1 SlotsOfSLResourcePoolinFrame(i)+slot start time ), SFN start time and slot start time being a subframe number (SFN) and logical slot, respectively, of the first transmission opportunity of PSSCH where the configured sidelink grant was (re-)initialized.