WO2022147781A1

WO2022147781A1 - Methods and apparatus for sidelink resource allocation

Info

Publication number: WO2022147781A1
Application number: PCT/CN2021/070927
Authority: WO
Inventors: Jing HAN; Zhennian SUN; Haiming Wang
Original assignee: Lenovo (Beijing) Limited
Priority date: 2021-01-08
Filing date: 2021-01-08
Publication date: 2022-07-14

Abstract

Disclosed are methods and apparatus for sidelink (SL) resource allocation. One embodiment of the subject application provides a method performed by a user equipment, including determining a first factor associated with a system frame and a second factor associated with a resource pool, and determining a SL resource period in the resource pool at least based on the first factor and the second factor, wherein the first factor is associated with SL synchronization signal/physical broadcast channel (S-SSB) slot configuration and reserved slot configuration in the system frame.

Description

METHODS AND APPARATUS FOR SIDELINK RESOURCE ALLOCATION

TECHNICAL FIELD

The present disclosure relates to methods and apparatus for sidelink (SL) resource allocation.

BACKGROUND OF THE INVENTION

A user equipment (UE) needs to allocate resources for performing SL transmissions, e.g., for Vehicle-to-Everything (V2X) , and the resources may be determined by the UE (e.g., SL mode 2) or by a base station (BS) (e.g., SL mode 1) .

To determine the resources in a resource pool for SL transmissions, SL slots that are to be actually used needs to be considered. For example, if a SL frequency band shares the UL frequency band, not all slots can be used for SL transmissions, e.g. the downlink (DL) slots or special slots.

Furthermore, in a resource pool, not all the slots can be used for a UE to perform SL transmission (s) . For example, a bit map of the resource pool determines that the slots marked with "1" may be used by the UE for performing SL transmissions, and other slots marked with "0" are used by other UEs for performing SL transmissions.

SUMMARY

In some embodiments, a method performed by a UE includes determining a first factor associated with a system frame and a second factor associated with a resource pool, and determining a SL resource period in the resource pool at least based on the first factor and the second factor, wherein the first factor is associated with SL synchronization signal/physical broadcast channel (S-SSB) slot configuration and reserved slot configuration in the system frame.

In some embodiments, the method further includes determining the second factor as K/L, wherein K is a total number of slot (s) marked with "1" within a bitmap, and L is a bitmap length of the resource pool in a time domain..

In some embodiments, determining the first factor further includes determining the number of non-SL slot (s) N _nonSL per system frame, the number of S-SSB slot (s) N _S-SSB per system frame, and the number of reserved slot (s) N _reserved per system frame in a physical layer.

In some embodiments, wherein determining the first factor further including determining the first factor as

wherein u is a subcarrier spacing.

In some embodiments, wherein the SL resource period is a SL configured grant (CG) period.

In some embodiments, wherein the first factor is determined in the physical layer.

In some embodiments, wherein determining the SL resource period in the resource pool at least based on the first factor and the second factor further includes allocating the SL resource period in the resource pool at least by

wherein, N is the number of slots that can be used for SL transmission (s) within 20 ms, and sl _periodCG is the SL CG period in ms.

In some embodiments, wherein the first factor is determined in a medium access control (MAC) layer.

In some embodiments, wherein the SL resource period is a SL resource reservation period.

wherein, N is the number of slots used for SL transmission (s) within 20 ms, and P _rsvp is a SL resource reservation period in ms.

In some embodiments, an apparatus includes a non-transitory computer-readable medium having stored thereon computer-executable instructions, a receiving circuitry, a transmitting circuitry, and a processor coupled to the non-transitory computer-readable medium, the receiving circuitry and the transmitting circuitry, and the computer-executable instructions are executable by the processor to cause the apparatus to implement various methods according embodiments of the present application.

BRIEF DESCRIPTION OF THE DRAWINGS

Some exemplary embodiments will now be described, by way of non-limiting examples, with reference to the accompanying drawings.

Figure 1 illustrates an exemplary legacy SL CG resource allocation in a resource pool.

Figure 2 illustrates an exemplary method according to some embodiments of the present disclosure.

Figure 3 illustrates an exemplary method according to some embodiments of the present disclosure.

Figure 4 illustrates an exemplary method according to some embodiments of the present disclosure.

Figure 5 illustrates an exemplary SL CG resource allocation according to the present disclosure.

Figure 6 illustrates an example apparatus according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

The detailed description of the appended drawings is intended as a description of the preferred embodiments of the present invention and is not intended to represent the only form in which the present invention may be practiced. It should be understood that the same or equivalent functions may be accomplished by different embodiments that are intended to be encompassed within the spirit and scope of the present invention.

Reference will now be made in detail to some methods, embodiments, and apparatuses of the present disclosure, examples of which are illustrated in the accompanying drawings. To facilitate understanding, these methods, embodiments, and apparatuses are provided under specific network architecture and new service scenarios, such as 3GPP (3rd Generation Partnership Project) 5G and so on. It is contemplated that along with developments of network architectures and new service scenarios, all embodiments in the present application are also applicable to similar technical problems, and moreover, the terminologies recited in the present application may change, which should not affect the principle of the present application.

The present disclosure relates to determining SL resources in a resource pool, specifically, the present disclosure relates to determining SL resources in time slots of a resource pool.

The SL resources can be categorized into 3 levels, as shown in Figure 1 which illustrates an exemplary SL CG resource allocation in a resource pool.

Level 1 includes physical slots on Uu interface which includes non-SL slots (e.g., downlink slots or special slots) , SL slots, S-SSB slots, reserved slots, and etc.

Level 2 includes only SL logical slots including SL slots, S-SSB slots, and reserved slots.

In level 1 and level 2, the SL slots (in white) are slots for performing SL transmissions; they are not limited to be used by one UE.

Level 3 includes only SL logical slots which belong to one resource pool excluding S-SSB slots and reserved slots. Level 3 is expressed by a bitmap whose length is configured in radio resource control (RRC) signaling. The slots marked with "0" and the slots marked with "1" in the resource pool belong to the SL slots shown in level 1 or level 2.

Currently, Equation 1 shown below is used for determining an SL CG resource period in a resource pool (e.g., for SL mode 1) :

In Equation 1, N is the number of slots that can be used for SL transmission (s) within 20 ms due to uplink-downlink (UL-DL) configuration, sl _periodCG is an SL CG resource period in ms, and PeriodicitySL is an SL CG resource period in slot (s) of a resource pool.

It can be seen that, in Equation 1, the S-SSB slots and reserved slots are not excluded when determining the SL resource period in slots of the resource pool (i.e., converting a SL resource period in ms to slots of level 2) . Accordingly, Equation 1 actually performs a SL CG resource period conversions based on level 2 logical slots.

Currently, Equation 2 shown below is used for determining an SL resource reservation period in a resource pool (e.g., for SL mode 2) :

In Equation 2, N is the number of slots that can be used for SL transmission (s) within 20 ms due to UL-DL configuration, P _rsvp is an SL resource reservation period in ms, and P _rsvp′ is an SL resource reservation period in slot (s) of a resource pool.

It can be seen that, in Equation 2, the S-SSB slots and reserved slots are not excluded as well when determining the SL resource period in slots of level 2. Accordingly, Equation 2 actually performs a SL resource reservation period conversions based on level 2 logical slots.

Therefore, Equation 1 and Equation 2 may result in some SL related resource being allocated out of the resource pool; in other words, for some SL related resources, corresponding resources are not allocated in the resource pool.

In the example shown in Figure 1, SFN represents subframe number, N is equal to 10, slperiodCG is 20 ms, and the length of the bitmap is 10.

If Equation 1 is used for determining the SL CG resource allocation in a resource pool, PeriodicitySL is 10.

According to Equation 1, some slots in level 2 (e.g., the second CG slot, the third CG slots, and the fourth CG slots) are allocated to slots marked with "0" in level 3 which is not allocated to resource pool and cannot be used by the UE. In other words, these CG slots have not been allocated as the resources in the resource pool. This may result in that the UE cannot perform transmission in reserved CG slot, misses the transmission opportunity, and introduces delay for data transmission.

When Equation 2 is used for determining the SL reserved resource allocation in a resource pool, similar problem may occur as well.

The present disclosure provides a method 200 for converting a SL resource period based on level 3 resource pool slots.

As shown in Figure 2, the method 200 at least includes an operation 210 and an operation 220. The operation 210 illustrates determining a first factor associated with a system frame and a second factor associated with a resource pool. The operation 220 illustrates determining an SL resource period in the resource pool at least based on the first factor and the second factor. Herein, the first factor is associated with S-SSB slot configuration and reserved slot configuration in the system frame.

In some embodiments, the SL resource period is a SL CG resource period. For example, when the SL mode is mode 1, the SL resource period is a SL CG resource period.

In some embodiments, the SL resource period is a SL resource reservation period. For example, when the SL mode is mode 2, the SL resource period is a SL resource reservation period.

In some embodiments, the first factor is determined as:

In

Equation

3, 10240 is a system frame length in ms, u is a subcarrier spacing obtained from the higher-layer parameter subcarrierSpacing, N _nonSL is the number of non-SL slot (s) per system frame in a physical layer, N _S-SSB is the number of S-SSB slot (s) per system frame in the physical layer, and N _reserved is the number of reserved slot (s) per system frame in the physical layer.

The motivation of using the first factor is to consider the existence of the S-SSB slots and the reserved slots when determining a SL resource period in slot (s) of a resource pool.

In some embodiments, the UE may determine the three parameters N _nonSL, N _S-SSB, and N _reserved in the physical layer.

In some embodiments, the second factor is determined as:

the second factor = K/L (Equation 4)

In Equation 4, K is a total number of slot (s) marked with "1" within a bitmap, and L is a bitmap length of the resource pool in a time domain.

In some embodiments, the parameters K and L are configured by an RRC signaling, and can be determined by the UE in the physical layer or in the MAC layer.

For example, referring back to Figure 1, the second factor is 2/5.

The motivation of using the second factor is to consider the actual resource pool configuration. For example, referring back to Figure 1, in a bitmap of the resource pool, only the slots marked with "1" can be used by the UE, these slots marked with "1" occupy 40%slots of the SL slots.

In some embodiments, if the SL resource period is a SL CG resource period, the UE may send the values of the three parameters N _nonSL, N _S-SSB, and N _reserved to a MAC layer, and the UE may determine the first factor in the MAC layer.

In some embodiments, if the SL resource period is a SL CG resource period, the UE may determine the first factor in the physical layer, and send the determined first factor to the MAC layer.

In some embodiments, if the SL resource period is an SL CG resource period, the UE may use following Equation 5 for determining the SL CG resource period in the resource pool:

In Equation 5, N is the number of slots that can be used for SL transmission (s) within 20 ms; sl _periodCG is an SL CG resource period in ms; and sl _{periodCG_RP} is an SL CG resource period in slot (s) of a resource pool.

Figure 3 illustrates an exemplary method 300 for determining an SL CG resource period in slots of a resource pool according to the method 200.

As shown in Figure 3, the method 300 at least includes four operations: 310, 320, 330, and 340.

The operation 310 determine the three parameters N _nonSL, N _S-SSB, and N _reserved.

The operation 320 determines the first factor as

(i.e., Equation 3) .

The operation 330 determines the second factor as K/L (i.e., Equation 4) .

The operation 340 determines an SL CG resource period sl _{periodCG_RP} in the resource pool at least according to

(i.e., Equation 5) .

In some embodiments, there is no strict restriction on the order of execution of

operations

310, 320, 330 and 340.

For example, the UE may determine the first factor first, and then determine the second factor.

For example, the UE may determine the second factor first, and then determine the first factor.

In some embodiments, if the SL resource period is a SL resource reservation period, the UE may determine the first factor in the physical layer.

In some embodiments, if the SL resource period is a SL resource reservation period, the UE may use following Equation 6 for determining the SL resource reservation period in the resource pool:

In Equation 6, N is the number of slots that can be used for SL transmission (s) within 20 ms, P _rsvp is an SL resource reservation period in ms, and P _{rsvp_Rp} is an SL resource reservation period in slots of a resource pool.

Figure 4 illustrates an exemplary method 400 for determining an SL resource reservation period in slots of a resource pool according to the method 200.

As shown in Figure 4, the method 400 at least includes four operations: 410, 420, 430, and 440.

The operation 410 determine the three parameters N _nonSL, N _S-SSB, and N _reserved.

The operation 420 determines the first factor as

(i.e., Equation 3) .

The operation 430 determines the second factor as K/L (i.e., Equation 4) .

The operation 440 determines an SL resource reservation period P _{rsvp_RP} in the resource pool at least according to

(i.e., Equation 6) .

operations

410, 420, 430 and 440.

Equation 5 and Equation 6 can be associated with the S-SSB slots, the reserved slots, and the actual configuration of a resource pool.

In Equation 5 and Equation 6, there can be some variants for the factor

For example, the factor

can be replaced with

wherein M is the number of slots that can be used for SL transmission (s) within the time period P in ms.

The present disclosure provides a solution for a UE to convert a SL resource in ms to slot (s) in a resource pool. According to the present disclosure, the S-SSB slots and reserved slots are not excluded by the use of the first factor, and the actual configuration of the resource pool is considered by the use of the second factor.

The advantage is that the SL related slots including CG slots and SL slots can be associated with slots marked with "1" (i.e., the slots in the resource pool that can be used by the UE) in the resource pool.

Figure 5 illustrates an exemplary result by using Equation 5 according to the present disclosure.

As shown in Figure 5, in contrasting with Figure 1, according to the solution of the present disclosure, all the four CG slots are allocated to the slots marked with "1" in the resource pool. This is because that, according to the solution of the present disclosure, the SL resource period is converted from ms to resource pool slots, the UE may count the period by resource pool slots and ensure that the allocated CG occasions occur in resource pool slots.

Figure 6 illustrates an exemplary apparatus 600 for performing the

methods

200, 300 or 400. The apparatus 600, for example, can be a part of a UE.

As shown in Figure 6, the apparatus 600 may include at least one receiving circuitry 610, at least one processor 620, at least one non-transitory computer-readable medium 630 with computer-executable code 640 stored thereon, and at least one transmitting circuitry 650. The at least one medium 630 and the computer-executable code 640 may be configured to, with the at least one processor 620, cause the apparatus 600 at least to perform at least the

example methods

200, 300 or 400 described above, wherein, for example, the apparatus 600 may be the UE in the

example methods

200, 300 or 400.

In various example embodiments, the at least one processor 620 may include, but not limited to, at least one hardware processor, including at least one microprocessor such as a CPU, a portion of at least one hardware processor, and any other suitable dedicated processor such as those developed based on for example Field Programmable Gate Array (FPGA) and Application Specific Integrated Circuit (ASIC) . Further, the at least one processor 620 may also include at least one other circuitry or element not shown in Figure 6.

In various example embodiments, the at least one non-transitory computer-readable medium 630 may include at least one storage medium in various forms, such as a volatile memory and/or a non-volatile memory. The volatile memory may include, but not limited to, for example, an RAM, a cache, and so on. The non-volatile memory may include, but not limited to, for example, an ROM, a hard disk, a flash memory, and so on. Further, the at least non-transitory computer-readable medium 630 may include, but are not limited to, an electric, a magnetic, an optical, an electromagnetic, an infrared, or a semiconductor system, apparatus, or device or any combination of the above.

Further, in various example embodiments, the exemplary apparatus 600 may also include at least one other circuitry, element, and interface, for example antenna element, and the like.

In various example embodiments, the circuitries, parts, elements, and interfaces in the exemplary apparatus 600, including the at least one processor 620 and the at least one non-transitory computer-readable medium 630, may be coupled together via any suitable connections including, but not limited to, buses, crossbars, wiring and/or wireless lines, in any suitable ways, for example electrically, magnetically, optically, electromagnetically, and the like.

The methods of the present disclosure can be implemented on a programmed processor. However, controllers, flowcharts, and modules may also be implemented on a general purpose or special purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit elements, an integrated circuit, a hardware electronic or logic circuit such as a discrete element circuit, a programmable logic device, or the like. In general, any device that has a finite state machine capable of implementing the flowcharts shown in the figures may be used to implement the processing functions of the present disclosure.

While the present disclosure has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. For example, various components of the embodiments may be interchanged, added, or substituted in other embodiments. Also, all of the elements shown in each figure are not necessary for operation of the disclosed embodiments. For example, one skilled in the art of the disclosed embodiments would be capable of making and using the teachings of the present disclosure by simply employing the elements of the independent claims. Accordingly, the embodiments of the present disclosure as set forth herein are intended to be illustrative, not limiting. Various changes may be made without departing from the spirit and scope of the present disclosure.

The terms "comprises, " "comprising, " "includes, " "including, " or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "a, " "an, " or the like does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element. Also, the term "another" is defined as at least a second or more. The terms "including, " "having, " and the like, as used herein, are defined as "comprising. "

Claims

A method performed by a user equipment (UE) , the method comprising:

determining a first factor associated with a system frame and a second factor associated with a resource pool; and

determining a sidelink (SL) resource period in the resource pool at least based on the first factor and the second factor, wherein

the first factor is associated with SL synchronization signal/physical broadcast channel (S-SSB) slot configuration and reserved slot configuration in the system frame.
The method of Claim 1, the method further comprises determining the second factor as K/L, wherein:

K is a total number of slot (s) marked with "1" within a bitmap; and

L is a bitmap length of the resource pool in a time domain.
The method of Claim 1, determining the first factor further comprising determining the number of non-SL slot (s) N _nonSL per system frame, the number of S-SSB slot (s) N _S-SSB per system frame, and the number of reserved slot (s) N _reserved per system frame in a physical layer.
The method of Claim 3, wherein determining the first factor further comprising determining the first factor as

wherein u is a subcarrier spacing.
The method of Claim 4, wherein the SL resource period is a SL configured grant (CG) period.
The method of Claim 5, wherein the first factor is determined in the physical layer.
The method of Claim 6, wherein determining the SL resource period in the resource pool at least based on the first factor and the second factor further comprises allocating the SL resource period in the resource pool at least by

wherein:

N is the number of slots that can be used for SL transmission (s) within 20 ms; and

sl _periodCG is the SL CG period in ms.
The method of Claim 5, wherein the first factor is determined in a medium access control (MAC) layer.
The method of Claim 8, wherein determining the SL resource period in the resource pool at least based on the first factor and the second factor further comprises allocating the SL resource period in the resource pool at least by

wherein:

N is the number of slots that can be used for SL transmission (s) within 20 ms; and

sl _periodCG is the SL CG period in ms.
The method of Claims 4, wherein the SL resource period is a SL resource reservation period.
The method of Claim 10, wherein the first factor is determined in the physical layer.
The method of Claim 11, wherein determining the SL resource period in the resource pool at least based on the first factor and the second factor further comprises allocating the SL resource period in the resource pool at least by

wherein:

N is the number of slots used for SL transmission (s) within 20 ms; and

P _rsvp is a SL resource reservation period in ms.
An apparatus, comprising:

a non-transitory computer-readable medium having stored thereon computer-executable instructions;

a receiving circuitry;

a transmitting circuitry; and

a processor coupled to the non-transitory computer-readable medium, the receiving circuitry and the transmitting circuitry,

wherein the computer-executable instructions are executable by the processor to cause the apparatus to implement the method of any one of Claims 1-12.