Patent Application
20210058900
The disclosure is directed to a method for performing a sidelink transmission, a transmitting user equipment (UE), and a receiving UE.
3GPP has launched a work item of new radio (NR) for vehicle-to-everything (V2X) in Release 16. Resources accesses in NR sidelink for V2X include Mode 1 and Mode 2, wherein Layer-1 feedback transmission are supported for both Mode 1 and Mode 2. In Mode 1, a base station schedules sidelink resources to be used for a UE to perform sidelink transmission. In Mode 2, a UE determines sidelink transmission resources within the sidelink resources configured by a base station or a network or within pre-configured sidelink resources. Traffic to be transmitted over sidelink for V2X has the characteristics such as periodic and aperiodic arrival, low latency and high reliability, and high traffic amount.
In Mode 2, each transmitting UE should perform channel sensing so as to alleviate occupying the same resources (and thus alleviated interference) with other transmitting UEs. However, for low latency sidelink transmissions, a transmitting UE should decrease the number in performing channel sensing.
To transmit a transport block (TB), a transmitting UE should be configured to: detect a physical sidelink control channel (PSCCH) transmitted by other transmitting UEs so as to know which resources are occupied by other transmitting UEs, wherein sidelink control information (SCI) indicating locations of physical sidelink shared channel (PSSCH) and physical sidelink feedback channel (PSFCH) may be conveyed via PSCCH; select resources for PSCCH, PSSCH (for initial transmissions, repetition transmissions, and retransmissions), and PSFCH; and provide scheduling assignment (i.e., SCI) in PSCCH, so that other transmitting UEs can know the locations of the resources which being occupied.
In Release 16, a transmitting UE could reserve resources for up to 32 transmissions, but usually the transmitting UE may not fully utilize these resources for retransmissions. For an example, for a TB retransmission, the resources corresponding to PSFCH is reserved. After an acknowledgement (ACK) is received in PSFCH before the maximum number (e.g., 30) of retransmissions has been reached, the remaining reserved resources (including PSSCH and PSFCH) are released.
In Mode 2, a transmitting UE should sense PSCCH (i.e., detect SCI) of other transmitting UEs in order to know the resources (i.e., PSCCH, PSSCH, and PSFCH) occupied by other transmitting UEs. However, after an ACK is received in PSFCH of other transmitting UEs and the remaining reserved resources (if any) are released, the transmitting UE may not know the remaining reserved resources of other transmitting UEs are released or not. Therefore, resources utilization may be degraded.
On the other hand, unicast, groupcast, and broadcast are supported in Mode 2. For unicast transmission, both ACK and NACK could be transmitted through PSFCH. The transmitting UE could transmit SCI including a transmitting UE identity (ID) and a receiving UE ID to the receiving UE. The receiving UE thus know that the transmitting UE would like to perform sidelink transmission with the receiving UE according to the SCI, and the receiving UE could determine to send sidelink feedback control information (SFCI) corresponding to the SCI to the transmitting UE. However, sending SFCI may cause some issues.
Assuming the distance between TX-A and TX-B is sufficiently far such that TX-A and TX-B cannot sense SCI from each other. TX-A and TX-B may reserve the same resources for corresponding PSFCH, SFCI feedbacked by RX-A and SFCI feedback by RX-B thus may allocated in the same PSFCH. TX-A may receive SFCI from both RX-A and RX-B, and SFCI from RX-B may cause interference to SFCI from RX-A.
For groupcast transmission, only NACK could be transmitted through PSFCH. The transmitting UE could transmit SCI including a transmitting UE ID and a receiving UE ID to the receiving UE. The receiving UE thus know that the transmitting UE would like to perform sidelink transmission with the receiving UE according to the SCI, and the receiving UE could determine to send SFCI corresponding to the SCI to the transmitting UE. However, sending SFCI may cause some issues.
To solve above issues, a method for performing a sidelink transmission, a transmitting user equipment (UE), and a receiving UE are provided in the disclosure.
A method for performing a sidelink transmission with a receiving user equipment (UE), adapted to a transmitting UE, comprising: detecting a resource pool for reserving a feedback resource, wherein the feedback resource is reserved according to a first occupied feedback resource and a second occupied feedback resource; transmitting a first signaling to the receiving UE; and receiving, from the receiving UE, a second signaling corresponding to the first signaling, wherein the second signaling is carried by the feedback resource.
A method for performing a sidelink transmission with a transmitting user equipment (UE), adapted to a receiving UE, comprising: receiving a first signaling from the transmitting UE; determining a first feedback resource according to the first signaling; and transmitting, to the transmitting UE, a second signaling corresponding to the first signaling via the first feedback resource, wherein the second signaling is generated according to one of a sequence with a first cyclic shift value, a sequence with a second cyclic shift value, or a sequence of a third cyclic shift value.
A transmitting user equipment (UE) for performing sidelink transmission with a receiving UE, comprising a transceiver and a processor. The transceiver communicatively connected to the receiving UE. The processor coupled to the transceiver and configured to: detect a resource pool for reserving a feedback resource, wherein the feedback resource is reserved according to a first occupied feedback resource and a second occupied feedback resource; transmit a first signaling to the receiving UE; and receive, from the receiving UE, a second signaling corresponding to the first signaling, wherein the second signaling is carried by the feedback resource.
A receiving user equipment (UE) for performing sidelink transmission with a transmitting UE, comprising a transceiver and a processor. The transceiver communicatively connected to the transmitting UE. The processor coupled to the transceiver and configured to: receive a first signaling from the transmitting UE; determine a first feedback resource according to the first signaling; and transmit, to the transmitting UE, a second signaling corresponding to the first signaling via the first feedback resource, wherein the second signaling is generated according to one of a sequence with first third cyclic shift value, a sequence with a second third cyclic shift value, or a sequence with a third cyclic shift value.
In order to make the aforementioned features and advantages of the present disclosure comprehensible, exemplary embodiments accompanied with figures are described in detail below. It is to be understood that both the foregoing general description and the following detailed description are exemplary, and are intended to provide further explanation of the disclosure as claimed.
It should be understood, however, that this summary may not contain all of the exemplary embodiments of the present disclosure and is therefore not meant to be limiting or restrictive in any manner. Also, the present disclosure would include improvements and modifications which are obvious to one skilled in the art.
The accompanying drawings are included to provide a further understanding of the disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the disclosure and, together with the description, serve to explain the principles of the disclosure.
Reference will now be made in detail to the present exemplary embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts.
The disclosure is directed to a method for performing a sidelink transmission, a transmitting user equipment (UE), and a receiving UE.
The processor 110 could be implemented by using programmable units such as a micro-processor, a micro-controller, a digital signal processor (DSP) chips, or a field programmable gate array (FPGA), etc. The functions of the processor 110 may also be implemented with separate electronic devices or ICs. It should be noted that the functions of processor 110 may be implemented with either hardware or software.
The storage medium 120 may be, for example, any type of fixed or removable random access memory (RAM), a read-only memory (ROM), a flash memory, a hard disk drive (HDD), a solid state drive (SSD) or similar element, or a combination thereof, configured to store a plurality of modules or various applications executable by the processor 110.
The transceiver 130 may be configured to transmit and receive signals respectively in the radio frequency or in the mmWave frequency. The transceiver 130 may also perform operations such as low noise amplifying, impedance matching, frequency mixing, up or down frequency conversion, filtering, amplifying, and so forth. The transceiver 130 may include one or more digital-to-analog (D/A) converters or analog-to-digital (A/D) converters which are configured to convert from an analog signal format to a digital signal format during uplink signal processing and from a digital signal format to an analog signal format during downlink signal processing. The transceiver 130 may include an antenna array which may include one or multiple antennas to transmit and receive omni-directional antenna beams or directional antenna beams.
The processor 210 could be implemented by using programmable units such as a micro-processor, a micro-controller, a DSP chips, or a FPGA, etc. The functions of the processor 210 may also be implemented with separate electronic devices or ICs. It should be noted that the functions of processor 210 may be implemented with either hardware or software.
The storage medium 220 may be, for example, any type of fixed or removable RAM, a ROM, a flash memory, a HDD, a SSD or similar element, or a combination thereof, configured to store a plurality of modules or various applications executable by the processor 210.
The transceiver 230 may be configured to transmit and receive signals respectively in the radio frequency or in the mmWave frequency. The transceiver 230 may also perform operations such as low noise amplifying, impedance matching, frequency mixing, up or down frequency conversion, filtering, amplifying, and so forth. The transceiver 230 may include one or more D/A converters or A/D converters which are configured to convert from an analog signal format to a digital signal format during uplink signal processing and from a digital signal format to an analog signal format during downlink signal processing. The transceiver 230 may include an antenna array which may include one or multiple antennas to transmit and receive omni-directional antenna beams or directional antenna beams.
In order to perform a sidelink transmission with UE 200, UE 100 may detect a resource pool for occupying one or more feedback resources. Specifically, UE 100 may detect an occupied control resource from the resource pool and determine the locations of one or more occupied feedback resources according to the occupied control resource, wherein the occupied control resource is occupied by the other transmitting UE and the occupied control resource may include SCI indicating the locations of the one or more occupied feedback resources. After determining the locations of occupied feedback resources which are occupied by the other transmitting UE, UE 100 may reserve one or more feedback resource for performing a sidelink transmission with UE 200 according to the occupied feedback resources which are occupied by the other transmitting UE. For example, UE 100 may avoid to reserving a feedback resource which has been occupied by the other transmitting UE.
UE 100 may further detect one or more occupied feedback resources which are occupied by the other transmitting UE and may determine whether the occupied feedback resources carry an ACK corresponding to the other UE. If an ACK is carried by one of the occupied feedback resources, UE 100 may determine that the remaining occupied feedback resources may be released. Thus, UE 100 may reserve the remaining occupied feedback resources as the feedback resource for performing sidelink transmission with UE 200. For example, if UE 100 detects an ACK is carried by PSFCH 42 which corresponds to PSCCH 31, UE 100 may determine that the remaining occupied feedback resources including PSSCH 43, PSFCH 44, and PSSCH 45 may be released. Thus, UE 100 may occupy a feedback resource corresponding to PSSCH 43, PSFCH 44, or PSSCH 45 for performing sidelink transmission with UE 200.
After occupying a control resource (e.g., PSCCH), a feedback resource (e.g., PSFCH), and a shared resource (e.g., PSSCH), UE 100 may transmit a first signaling to UE 200 through the control resource, wherein the first signaling may be SCI. The SCI may indicate the locations of the feedback resource and the shared resource corresponding to the control resource. UE 200 may determine the feedback resource and the shared resource according to SCI included in the first signaling, wherein the first signaling may be carried by the control resource. For example, UE 100 may transmit a first signaling to UE 200 through PSCCH 31, wherein SCI included in the first signaling may indicate the locations of PSSCH 41, PSFCH 42, PSSCH 43, PSFCH 44, and PSSCH 45, wherein PSSCH 41, PSFCH 42, PSSCH 43, PSFCH 44, and PSSCH 45 have been occupied by UE 100. UE 200 may determine the locations of PSSCH 41, PSFCH 42, PSSCH 43, PSFCH 44, and PSSCH 45 according to SCI included in the first signaling.
After determining the locations of the shared resource and the feedback resource according to the SCI including in the first signaling, UE 200 may try to receive data transmitted by UE 100 through the shared resource. If UE 200 does not successfully receive the data through the shared resource, UE 200 may determine to transmit a NACK sequence to UE 100. If UE 200 successfully receive the data through the shared resource, UE 200 may or may not determine to transmit an ACK sequence to UE 100. UE 200 may generate a second signaling corresponding to the first signaling, wherein the second signaling may be SFCI, and the SFCI may be associated with an ACK sequence or a NACK sequence. UE 200 may transmit the second signaling to UE 100 through the feedback resource indicated by the SCI. UE 100 may receive the second signaling through the feedback resource. UE 100 may decode the second signaling to recognize the source of the second signaling and to determine that the second signaling is associated with an ACK sequence or a NACK sequence. If the second signaling is associated with a NACK sequence, UE 100 may determine to perform a retransmission with UE 200 by using the remaining shared resource. If the second signaling is associated with an ACK sequence, UE 100 may determine to release the remaining reserved resources.
For example, after receiving the SCI from PSCCH 31, UE 200 may try to receive data transmitted by UE 100 through PSSCH 41. If UE 200 does not successfully receive the data through PSSCH 41, UE 200 may generate a second signaling associated with a NACK sequence and may transmit the second signaling to UE 100 through PSFCH 42. If UE 100 receives the second signaling from UE 200 through PSFCH 42 and determines that the second signaling is associated with a NACK sequence, UE 100 may re-transmit the data to UE 200 through PSSCH 43. If UE 200 successfully receive the data through PSSCH 43, UE 200 may generate a second signaling associated with an ACK sequence and may transmit the second signaling to UE 100 through PSFCH 44. If UE 100 receives the second signaling from UE 200 through PSFCH 44 and determines that the second signaling is associated with an ACK sequence, UE 100 may release the remaining reserved resources such as PSSCH 45.
UE 200 may transmit the second signaling to UE 100 through the feedback resource. After receiving the second signaling, UE 100 may decode the second signaling to determine if the second signaling is corresponded to an ACK or a NACK. Specifically, UE 100 may determine the second signaling is corresponded to an ACK in response to successfully decoding the second signaling according to the first cyclic shift value, and may determine the second signaling is corresponded to a NACK in response to successfully decoding the second signaling according to the second cyclic shift value, wherein the first cyclic shift value and the second cyclic shift value may be derived by the ID of UE 100, wherein the ID of UE 100 may be pre-stored in the storage medium 120 of UE 100. In response to successfully decoding the second signaling according to the first cyclic shift value or the second cyclic shift value, UE 100 may determine that the target of the second signaling is UE 100 since the first cyclic shift value or the second cyclic shift value could be derived by the ID of UE 100.
UE 200 may transmit the second signaling to UE 100 through the feedback resource. After receiving the second signaling, UE 100 may decode the second signaling to determine if the second signaling is corresponded to a NACK. Specifically, UE 100 may determine the second signaling is corresponded to a NACK in response to successfully decoding the second signaling according to the third cyclic shift value, wherein the third cyclic shift value may be derived by the ID of UE 100 and the ID of UE 200, wherein the ID of UE 100 and the ID of UE 200 may be pre-storage in the storage medium 120 of UE 100. In response to successfully decoding the second signaling according to the third cyclic shift value, UE 100 may determine that the target of the second signaling is UE 100 and the source of the second signaling is UE 200 since the third cyclic shift value could be derived by the ID of UE 100 and the ID of UE 200. Accordingly, UE 100 may determine, from a plurality of UE in the same group, the source of a received SFCI.
In view of the aforementioned descriptions, a transmitting UE may detect PSFCH of another transmitting UE so as to find out whether some resources are released by other transmitting UE or not, and may schedule sidelink resources accordingly. A receiving UE may generate ACK sequence and NACK sequence with different cyclic shift value, wherein each of the cyclic shift value may derived by an ID of the transmitting UE and may further derived by an ID of the receiving UE. After receiving SFCI from the receiving UE, the transmitting UE may determine the source and the content of the SFCI based on the cyclic shift value used by the SFCI.
No element, act, or instruction used in the detailed description of disclosed embodiments of the present application should be construed as absolutely critical or essential to the present disclosure unless explicitly described as such. Also, as used herein, each of the indefinite articles “a” and “an” could include more than one item. If only one item is intended, the terms “a single” or similar languages would be used. Furthermore, the terms “any of” followed by a listing of a plurality of items and/or a plurality of categories of items, as used herein, are intended to include “any of”, “any combination of”, “any multiple of”, and/or “any combination of” multiples of the items and/or the categories of items, individually or in conjunction with other items and/or other categories of items. Further, as used herein, the term “set” is intended to include any number of items, including zero. Further, as used herein, the term “number” is intended to include any number, including zero.
It will be apparent to those skilled in the art that various modifications and variations could be made to the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure covers modifications and variations provided that they fall within the scope of the following claims and their equivalents.
This application claims the priority benefit of U.S. provisional application Ser. No. 62/889,567, filed on Aug. 21, 2019. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
| Number | Date | Country | |
|---|---|---|---|
| 62889567 | Aug 2019 | US |
