WO2022000186A1

WO2022000186A1 - Methods and apparatuses of saving power for a sidelink

Info

Publication number: WO2022000186A1
Application number: PCT/CN2020/098914
Authority: WO
Inventors: Xiaodong Yu; Zhennian SUN; Haipeng Lei; Xin Guo
Original assignee: Lenovo (Beijing) Limited
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2022-01-06

Abstract

Embodiments of the present disclosure relate to methods and apparatuses of saving power for a sidelink under 3GPP (3rd Generation Partnership Project) 5G new radio (NR). According to an embodiment of the present disclosure, a method includes: receiving sidelink configuration information; performing blind detection in a configured time and frequency resource region; receiving, in the configured time and frequency resource region, a sidelink transmission including sidelink control information (SCI); and performing sidelink transmission detection in a target time and frequency resource region according to at least one of the sidelink configuration information and the SCI in the sidelink transmission.

Description

METHODS AND APPARATUSES OF SAVING POWER FOR A SIDELINK

TECHNICAL FIELD

Embodiments of the present disclosure are related to wireless communication technology, and more particularly, related to methods and apparatuses of saving power for a sidelink under 3GPP (3rd Generation Partnership Project) 5G new radio (NR) .

BACKGROUND

Vehicle to everything (V2X) has been introduced into 5G wireless communication technology. In terms of a channel structure of V2X communication, the direct link between two user equipments (UEs) is called a sidelink. A sidelink is a long-term evolution (LTE) feature introduced in 3GPP Release 12, and enables a direct communication between proximal UEs, and data does not need to go through a base station (BS) or a core network.

5G and/or NR networks are expected to increase network throughput, coverage, and robustness and reduce latency and power consumption. With the development of 5G and NR networks, various aspects need to be studied and developed to perfect the 5G and/or NR technology.

SUMMARY

One object of embodiments of the present disclosure is to provide novel mechanisms for power saving and resource reservation in a sidelink communication system.

Some embodiments of the present application provide a method for sidelink communications. The method may be performed by a user equipment (UE) , e.g., a sidelink reception UE. The method includes: receiving sidelink configuration information; performing blind detection in a configured time and frequency resource region; receiving, in the configured time and frequency resource region, a sidelink transmission including sidelink control information (SCI) ; and performing sidelink transmission detection in a target time and frequency resource region according to at least one of the sidelink configuration information and the SCI in the sidelink transmission.

Some embodiments of the present application provide an apparatus. The 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, wherein the computer-executable instructions cause the processor to implement the abovementioned method for sidelink communications performed by a reception UE.

Some embodiments of the present application provide a further method for sidelink communications. The method may be performed by a UE, e.g., a sidelink transmission UE. The method includes: transmitting sidelink configuration information; and transmitting a sidelink transmission including sidelink control information (SCI) , wherein the sidelink configuration information indicates whether a sidelink reception UE only performs sidelink transmission detection in a target time and frequency resource region after the sidelink reception UE receives the sidelink transmission.

Some embodiments of the present application provide an apparatus. The 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, wherein the computer-executable instructions cause the processor to implement the abovementioned method for sidelink communications performed by a transmission UE.

The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which advantages and features of the present disclosure can be obtained, a description of the present disclosure is rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. These drawings depict only exemplary embodiments of the present disclosure and are not therefore intended to limit the scope of the present disclosure.

FIG. 1 illustrates an exemplary V2X communication system in accordance with some embodiments of the present application.

FIG. 2 illustrates an example timing diagrams of DRX cycles according to some embodiments of the present disclosure.

FIG. 3 illustrates a diagram of a resource reservation mechanism for a subsequent transport block (TB) according to some embodiments of the present disclosure.

FIG. 4 illustrates a flow chart of a method for saving power in a sidelink communication system according to some embodiments of the present disclosure.

FIG. 5 illustrates a further flow chart of a method for saving power in a sidelink communication system according to some embodiments of the present disclosure.

FIG. 6 illustrates an exemplary diagram of a resource reservation mechanism according to some embodiments of the present disclosure.

FIG. 7 illustrates a further exemplary diagram of a resource reservation mechanism according to some embodiments of the present disclosure.

FIG. 8 illustrates another exemplary diagram of a resource reservation mechanism according to some embodiments of the present disclosure.

FIG. 9 illustrates yet another exemplary diagram of a resource reservation mechanism according to some embodiments of the present disclosure.

FIG. 10 illustrates yet another exemplary diagram of a resource reservation mechanism according to some embodiments of the present disclosure.

FIG. 11 illustrates yet another exemplary diagram of a resource reservation mechanism according to some embodiments of the present disclosure.

FIG. 12 illustrates an exemplary block diagram of an apparatus according to some embodiments of the present disclosure.

FIG. 13 illustrates a further exemplary block diagram of an apparatus according to some embodiments of the present disclosure.

DETAILED DESCRIPTION

The detailed description of the appended drawings is intended as a description of preferred embodiments of the present application and is not intended to represent the only form in which the present application 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 application.

Reference will now be made in detail to some embodiments of the present application, examples of which are illustrated in the accompanying drawings. To facilitate understanding, embodiments are provided under specific network architecture and new service scenarios, such as 3GPP 5G, 3GPP LTE Release 8, B5G, 6G, 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.

As shown in FIG. 1, a wireless communication system 100 includes at least one user equipment (UE) 101 and at least one base station (BS) 102. In particular, the wireless communication system 100 includes two UEs 101 (e.g., UE 101a and UE 101b) and one BS 102 for illustrative purpose. Although a specific number of UEs 101 and BS 102 are depicted in FIG. 1, it is contemplated that any number of UEs 101 and BSs 102 may be included in the wireless communication system 100.

The UE (s) 101 may include computing devices, such as desktop computers, laptop computers, personal digital assistants (PDAs) , tablet computers, smart televisions (e.g., televisions connected to the Internet) , set-top boxes, game consoles, security systems (including security cameras) , vehicle on-board computers, network devices (e.g., routers, switches, and modems) , or the like. According to some embodiments of the present application, the UE (s) 101 may include a portable wireless communication device, a smart phone, a cellular telephone, a flip phone, a device having a subscriber identity module, a personal computer, a selective call receiver, or any other device that is capable of sending and receiving communication signals on a wireless network.

In some embodiments of the present application, UE is pedestrian UE (P-UE or PUE) or cyclist UE. In some embodiments of the present application, the UE (s) 101 includes wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, the UE (s) 101 may be referred to as a subscriber unit, a mobile, a mobile station, a user, a terminal, a mobile terminal, a wireless terminal, a fixed terminal, a subscriber station, a user terminal, or a device, or described using other terminology used in the art. The UE (s) 101 may communicate directly with BSs 102 via LTE or NR Uu interface.

In some embodiments of the present application, each of the UE (s) 101 may be deployed an IoT application, an eMBB application and/or a URLLC application. For instance, UE 101a may implement an IoT application and may be named as an IoT UE, while UE 101b may implement an eMBB application and/or a URLLC application and may be named as an eMBB UE, an URLLC UE, or an eMBB/URLLC UE. It is contemplated that the specific type of application (s) deployed in the UE (s) 101 may be varied and not limited.

In a V2X communication system, a transmission UE may also be named as a transmitting UE, a Tx UE, or a sidelink Tx UE. A reception UE may also be named as a receiving UE, a Rx UE, or a sidelink Rx UE.

According to some embodiments of FIG. 1, UE 101a functions as a Tx UE, and UE 101b functions as a Rx UE. UE 101a may exchange V2X messages with UE 101b through a sidelink, for example, PC5 interface as defined in 3GPP TS 23.303. UE 101a may transmit information or data to other UE (s) within the V2X communication system, through sidelink unicast, sidelink groupcast, or sidelink broadcast. For instance, UE 101a transmits data to UE 101b in a sidelink unicast session. UE 101a may transmit data to UE 101b and other UEs in a groupcast group (not shown in FIG. 1) by a sidelink groupcast transmission session. Also, UE 101a may transmit data to UE 101b and other UEs (not shown in FIG. 1) by a sidelink broadcast transmission session.

Alternatively, according to some other embodiments of FIG. 1, UE 101b functions as a Tx UE and transmits V2X messages, UE 101a functions as a Rx UE and receives the V2X messages from UE 101b.

Both UE 101a and UE 101b in the embodiments of FIG. 1 may transmit information to BS 102 and receive control information from BS 102, for example, via LTE or NR Uu interface. The BS (s) 102 may be distributed over a geographic region. In certain embodiments of the present application, each of the BS (s) 102 may also be referred to as an access point, an access terminal, a base, a base unit, a macro cell, a Node-B, an evolved Node B (eNB) , a gNB, a Home Node-B, a relay node, or a device, or described using other terminology used in the art. The BS (s) 102 is generally a part of a radio access network that may include one or more controllers communicably coupled to one or more corresponding BS (s) 102.

The wireless communication system 100 may be compatible with any type of network that is capable of sending and receiving wireless communication signals. For example, the wireless communication system 100 is compatible with a wireless communication network, a cellular telephone network, a Time Division Multiple Access (TDMA) -based network, a Code Division Multiple Access (CDMA) -based network, an Orthogonal Frequency Division Multiple Access (OFDMA) -based network, an LTE network, a 3GPP-based network, a 3GPP 5G network, a satellite communications network, a high altitude platform network, and/or other communications networks.

In some embodiments of the present application, the wireless communication system 100 is compatible with the 5G NR of the 3GPP protocol, wherein BS (s) 102 transmit data using an OFDM modulation scheme on the downlink (DL) and the UE (s) 101 transmit data on the uplink (UL) using a Discrete Fourier Transform-Spread-Orthogonal Frequency Division Multiplexing (DFT-S-OFDM) or cyclic prefix-OFDM (CP-OFDM) scheme. More generally, however, the wireless communication system 100 may implement some other open or proprietary communication protocols, for example, WiMAX, among other protocols.

In some embodiments of the present application, the BS (s) 102 may communicate using other communication protocols, such as the IEEE 802.11 family of wireless communication protocols. Further, in some embodiments of the present application, the BS (s) 102 may communicate over licensed spectrums, whereas in other embodiments, the BS (s) 102 may communicate over unlicensed spectrums. The present application is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol. In yet some embodiments of present application, the BS (s) 102 may communicate with the UE (s) 101 using the 3GPP 5G protocols.

The UE (s) 101 may access the BS (s) 102 to receive data packets from the BS (s) 102 via a downlink channel and/or transmit data packets to the BS (s) 102 via an uplink channel. In normal operation, since the UE (s) 101 does not know when the BS (s) 102 will transmit data packets to it, the UE (s) 101 has to be awake all the time to monitor the downlink channel (e.g., a Physical Downlink Control Channel (PDCCH) ) to get ready for receiving data packets from the BS (s) 102. However, if the UE (s) 101 keeps monitoring the downlink channel all the time even when there is no traffic between the BS (s) 102 and the UE (s) 101, it would result in significant power waste, which is problematic to a power limited or power sensitive UE.

Discontinuous reception (DRX) can be used to resolve the above issue. DRX is a mechanism in which a UE gets into a sleep mode for a certain period of time (which is referred to as "OFF time, " "OFF period, " "OFF duration" or "off-duration" interchangeably herein) , wakes up for another period of time (which is referred to as "ON time, " "ON period, " "ON duration" or "on-duration" interchangeably herein) , and periodically repeats this cycle. When the UE gets into the sleep mode, the UE is in an OFF state. When the UE wakes up, the UE is in an ON state. To synchronize the UE-wakeup timing with the transmission timing of the BS for the UE, the BS may configure DRX parameters for the UE and signal the DRX parameters to the UE using a Radio Resource Control (RRC) message.

DRX parameters may indicate to the UE when and how long it should be awake to monitor a downlink channel. The following Table 1 shows some exemplary DRX parameters and their respective meanings.

Table 1

Specifically, FIG. 2 illustrates a scenario where only long DRX cycle type is configured for a UE (two exemplary long DRX cycles are shown, i.e., 1 ^st DRX cycle and 2 ^nd DRX cycle) , and no PDCCH is received during the shown DRX cycles.

As shown in FIG. 2, 1 ^st DRX cycle is from T1 to T3, and 2 ^nd DRX cycle is from T3 to T5. 1 ^st ON duration in the 1 ^st DRX cycle is from T1 to T2, in which the UE remains in the ON state to monitor and receive PDCCH if any; and the OFF duration in the 1 ^st DRX cycle is from T2 to T3, in which the UE remains in the OFF state to save power. Similarly, 2 ^nd ON duration in the 2 ^nd DRX cycle is from T3 to T4, and the OFF duration in the 2 ^nd DRX cycle is from T4 to T5. 3 ^rd ON duration is of the same time length.

The cases of DRC cycles in FIG. 2 are provided only for illustration purposes. Those skilled in the art will understand that there can be an infinite number of different combinations of these embodiments.

As discussed above, in the legacy DRX mechanism, the DRX parameters are configured by the BS for the UE. Accordingly, the BS well knows the reception state of the UE and can transmit data to the UE via a downlink channel during the ON duration of the UE. When the DRX mechanism is applied to sidelink communication between a TX UE and a RX UE, the BS may configure DRX parameters for each UE.

A DRX mechanism is supported in downlink and will be introduced in 5G NR sidelink. A resource reservation mechanism for a different TB is supported in 3GPP Release 16 of a NR V2X communication system. However, there is no mechanism to consider a power sensitive UE who is configured with sidelink DRX configuration information.

A power saving mechanism enables a UE with battery constraint to perform sidelink operations in a power efficient manner. 3GPP Release 16 NR sidelink is designed based on the assumption of "always-on" when a UE operates a sidelink, e.g., only focusing on UEs installed in vehicles with sufficient battery capacity. Solutions for power saving in 3GPP Release 17 are required for vulnerable road users (VRUs) in V2X use cases and for a UE in public safety and commercial use cases, in which power consumption in the UE needs to be minimized.

An enhanced reliability and reduced latency mechanism allows the support of URLLC (Ultra-Reliable and Low Latency Communications) -type sidelink use cases in wider operation scenarios. The system level reliability and latency performance of a sidelink is affected by the communication conditions, such as the wireless channel status and the offered load. 3GPP Release 16 NR sidelink is expected to have a limitation in achieving high reliability and low latency in some conditions, e.g., when the channel is relatively busy. Solutions that can enhance reliability and reduce latency are required, in order to keep providing the use cases requiring low latency and high reliability under such communication conditions. A mechanism is needed so that a Rx UE who is a power sensitive UE and configured with DRX mechanism can perform sidelink reception with reduced power.

Embodiments of the present disclosure provide mechanisms of sidelink resource reservation and power saving for a sidelink communication system, and will be specifically described below. Some embodiments may be combined with the DRX mechanism to implement the mechanisms of sidelink resource reservation and power saving.

As shown in FIG. 3, two windows are marked as "W1" and W2, respectively, and each window includes three transmissions. Specifically, the window W1 includes an initial transmission of TB1 and two reserved re-transmissions for the same TB (i.e., TB1) . The initial transmission of TB1 includes SCI, and the SCI indicates a resource reserved for each of the two reserved re-transmissions in window W1. The window W2 includes three reserved transmissions for another TB, i.e., TB2 as shown in FIG. 3, which is a subsequent TB of TB1. As shown in FIG. 3, the SCI in the initial transmission of TB1 in window W1 also indicates resources reserved for the three reserved transmissions for TB2 in window W2.

Currently, under a 3GPP 5G system or the like, there are the following agreements. On a per resource pool basis, when enabling a sidelink resource reservation for an initial transmission of a TB (e.g., TB2 as shown in FIG. 3) at least by an SCI associated with a different TB (e.g., TB1 as shown in FIG. 3) :

(1) A period is additionally signaled in the SCI (for example, a period shown in FIG. 3) . The same reservation is applied with respect to resources indicated within a window W at subsequent periods.

(2) A set of possible period values of the period is: {0, [1: 99] , 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000 } ms.

● A filed in the SCI (e.g., <= 4 bits) may be used to indicate the value of the period.

● An actual set of values of the period may be pre-configured or configured.

(3) Regarding the number of period (s)

● The number of remaining periodic reservations is not explicitly indicated in the SCI.

Referring back to FIG. 3, the SCI in the initial transmission of TB1 in window W1 also indicates a period between two windows W1 and W2. As can be seen from FIG. 3, the period is from a start point of the initial transmission in window W1 to a start point of the first reserved transmission in window W2. As described above, a value of the period in the embodiments of FIG. 3 may be selected from the group: {0, [1: 99] , 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000 } ms.

The embodiments of FIG. 4 may be performed by a UE or a Rx UE (e.g., UE 101a or UE 101b illustrated and shown in FIG. 1) . Although described with respect to a UE, it should be understood that other devices may be configured to perform a method similar to that of FIG. 4.

In the exemplary method 400 as shown in FIG. 4, in operation 401, a UE receives sidelink configuration information. For instance, the UE receives sidelink configuration information from a network, a BS, and a sidelink Tx UE.

According to some embodiments of the present disclosure, the sidelink configuration information is transmitted in a common RRC signaling. According to some other embodiments of the present disclosure, the sidelink configuration information is transmitted in a dedicated RRC signaling. The sidelink configuration information may include any additional configuration as described above.

In operation 402, the UE performs blind detection in a configured time and frequency resource region. According to some embodiments of the present disclosure, the configured time and frequency resource region is a resource pool. According to some other embodiments of the present disclosure, the configured time and frequency resource region is an on-duration of a DRX cycle.

According to some additional embodiments of the present disclosure, the configured time and frequency resource region is a subset of resources within an on-duration of a DRX cycle. The subset of resources may be configured by DRX configuration information included in the sidelink configuration information. Alternatively, the subset of resource may be determined based on a sensing result of a sidelink transmission UE.

Referring back to FIG. 4, in operation 403, the UE receives, in the configured time and frequency resource region, a sidelink transmission including SCI. The received sidelink transmission may be an initial transmission of a TB.

In operation 404, the UE performs sidelink transmission detection in a target time and frequency resource region according to at least one of the sidelink configuration information received in operation 401 and the SCI in the sidelink transmission received in operation 403.

In some embodiments of the present disclosure, the sidelink configuration information includes resource pool configuration information. The resource pool configuration information may include a field to indicate whether the UE only performs the sidelink transmission detection in a target time and frequency resource region.

In some other embodiments of the present disclosure, the sidelink configuration information includes DRX configuration information. The DRX configuration information may include a field to indicate whether the UE only performs the sidelink transmission detection in a target time and frequency resource region.

In some other embodiments of the present disclosure, the SCI in the sidelink transmission includes a field to indicate whether the UE only performs the sidelink transmission detection in a target time and frequency resource region. The field may include 1 bit. For example, value ‘1’ of the bit represents only performing the sidelink transmission detection in the target time and frequency resource region, and value ‘0’ of the bit represents performing blind detection in the target time and frequency resource region and one or more other resources; and vice versa.

The target time and frequency resource region may include a reserved resource, and the reserved resource is indicated by the SCI in the sidelink transmission received in operation 403. The target time and frequency resource region may include one or more non-reserved resources.

In the target time and frequency resource region, a location of non-reserved resource (s) in time and frequency domain is associated with a location of reserved resource (s) in the time and frequency domain. A location relation between a location of reserved resource (s) in time and frequency domain and a location of non-reserved resource (s) in time and frequency domain may be pre-configured or configured.

According to some embodiments of the present disclosure, the target time and frequency resource region is a candidate resource set. The candidate resource set includes reserved resource (s) and non-reserved resource (s) . For example, the candidate resource set may be determined based on a sensing result of a sidelink transmission UE, and the candidate resource set is transmitted from the sidelink transmission UE to a sidelink reception UE (e.g., by RRC signaling) . Alternatively, the candidate resource set is pre-configured or configured.

According to some embodiments of the present disclosure, the UE may further receive another sidelink transmission in the target time and frequency resource region. The abovementioned another sidelink transmission may be a control transmission and/or a data transmission. The above mentioned another sidelink transmission may be an initial transmission of a TB. Alternatively, the above mentioned another sidelink transmission may be a re-transmission of the sidelink transmission received in operation 403.

In some other embodiments of the present disclosure, the sidelink configuration information received in operation 401 includes one or more pieces of DRX configuration information. Each piece of DRX configuration information may include an expected number of initial transmissions of a TB. In these embodiments, the UE determines a total expected number of initial transmissions based on all the expected number of initial transmissions included in the sidelink configuration information.

When the sidelink transmission received in operation 403 is an initial transmission of a TB, the UE performing sidelink transmission detection may further comprises the following operations:

● The UE performs a blind detection in the configured time and frequency resource region and receives one or more initial transmissions of the TB according to the total expected number of initial transmissions.

The configured time and frequency resource region may include one or more on-durations. These one or more on-durations may be indicated by one or more pieces of DRX configuration information transmitted from one or more Tx UEs. Theses on-durations may be aligned or overlapped. In particular, on-durations of different DRX cycles of different Tx UEs may be of the same length in time domain.

For example, two on-durations indicated by two pieces of DRX configuration information transmitted from two Tx UEs are overlapped, and the configured time and frequency resource region includes the overlapped on-duration. Then, the UE performs a blind detection in the overlapped on-duration. In this example, two on-durations of these two pieces of DRX configuration information of these two Tx UEs are aligned, whereas a DRX cycle of one Tx UE may be of the same or different length in time domain from that of a DRX cycle of the other one Tx UE.

● After a total number of received initial transmissions of the TB reaches to the total expected number of initial transmissions, the UE performs a sidelink transmission detection in the target time and frequency resource region.

In some embodiments of the present disclosure, the UE receives, in the configured time and frequency resource region, a further sidelink transmission including SCI. The further sidelink transmission may be a subsequent initial transmission of a TB, in view of the sidelink transmission received in operation 403. The SCI in this further sidelink transmission may have the same format and functions as those of the SCI in the sidelink transmission received in operation 403.

According to some embodiments of the present disclosure, the SCI in the sidelink transmission received in operation 403 includes one or more reserved resources and a field, and the field indicates a usage of the one or more reserved resources. The field may include 1 bit. For example, value ‘1’ of the bit represents that the one or more reserved resources are used for detecting an initial transmission and its associated re-transmission, and value ‘0’ of the bit represents that the one or more reserved resources are used for detecting an initial transmission, and vice versa.

Details described in the embodiments as illustrated and shown in FIGS. 1-3 and 5-13, especially, contents related to specific operations for saving power of a UE in a sidelink communication system, are applicable for the embodiments as illustrated and shown in FIG. 4. Moreover, details described in the embodiments of FIG. 4 are applicable for all the embodiments of FIGS. 1-3 and 5-13.

The embodiments of FIG. 5 may be performed by a UE or a Tx UE (e.g., UE 101a or UE 101b illustrated and shown in FIG. 1) . Although described with respect to a UE, it should be understood that other devices may be configured to perform a method similar to that of FIG. 5.

As shown in FIG. 5, in operation 501, a UE transmits sidelink configuration information. According to some embodiments of the present disclosure, the sidelink configuration information is received from a network or a BS.

According to some embodiments of the present disclosure, the sidelink configuration information includes resource pool configuration information. The resource pool configuration information includes a field to indicate whether the sidelink Rx UE only performs the sidelink transmission detection in the target time and frequency resource region.

According to some other embodiments of the present disclosure, the sidelink configuration information includes DRX configuration information. In an embodiment, the DRX configuration information may include a field to indicate whether the sidelink Rx UE only performs the sidelink transmission detection in the target time and frequency resource region. In another embodiment, the DRX configuration information includes an expected number of initial transmissions, and the expected number of initial transmissions indicates a total number of the sidelink transmission and one or more initial transmissions transmitted by one or multiple sidelink transmission UEs.

Referring back to FIG. 5, in operation 502, the UE transmits a sidelink transmission including SCI. At least one of the sidelink configuration information and the SCI indicates whether a sidelink Rx UE only performs sidelink transmission detection in a target time and frequency resource region after the sidelink Rx UE receives the sidelink transmission.

According to some embodiments of the present disclosure, the SCI in the sidelink transmission includes one or more reserved resources and a field, and the field indicates a usage of the one or more reserved resources. The field may include 1 bit. For example, value ‘1’ of the bit represents that the one or more reserved resources are used for detecting an initial transmission and its associated re-transmission, and value ‘0’ of the bit represents that the one or more reserved resources are used for detecting an initial transmission, and vice versa.

Details described in the embodiments as illustrated and shown in FIGS. 1-4 and 6-13, especially, contents related to specific operations for saving power of a UE in a sidelink communication system, are applicable for the embodiments as illustrated and shown in FIG. 5. Moreover, details described in the embodiments of FIG. 5 are applicable for all the embodiments of FIGS. 1-4 and 6-13.

The following texts describe several exemplary embodiments of Solutions 1-7 of the present disclosure as below. Under some scenarios, each embodiment of Solutions 1-7 may be combined with each other in specific implementations. Those skilled in the art will understand that there can be an infinite number of different combinations of these embodiments.

Solution 1

In some embodiments of the present disclosure, if a sidelink DRX configuration is configured to a Rx UE, during the on-duration of a DRX cycle, the Rx UE performs sidelink reception, i.e., monitoring SCI and decoding its associated data transmission. When the Rx UE receives an initial transmission of a TB, i.e., an excepted transmission of a TB, the received SCI can indicate a resource reservation for a different TB (e.g., a subsequent TB) in the on-duration of a subsequent DRX cycle.

In other words, in these embodiments, the Rx UE can only detect the indicated reserved resource (s) , to determine whether there is SCI and its associated data transmission in the indicated reserved resource (s) or not. Comparing with detecting each potential resource (s) for SCI and its associated data transmission, these embodiments will reduce the number of blind detection and save the power consumption of a Rx UE. A specific example is described in FIG. 6.

The embodiments of FIG. 6 show one DRX cycle and two ON durations in time and frequency domains, i.e., 1 ^st DRX cycle, 1 ^st ON duration within 1 ^st DRX cycle, and 2 ^nd ON duration within another DRX cycle (not shown in FIG. 6) . Each ON duration includes one or more time-frequency resource units. For example, FIG. 6 shows that each of 1 ^st and 2 ^nd ON durations includes 24 time-frequency resource units.

Although a specific number of DRX cycles, a specific number of ON durations, and a specific number of time-frequency resource units within a ON duration are depicted in FIG. 6, it is contemplated that any number of DRX cycles, any number of ON durations, and any number of time-frequency resource units within a ON duration may be included in the embodiments of FIG. 6.

A time-frequency resource unit represents a frequency domain resource (e.g., a sub-channel) *time domain resource (e.g., a time slot, for example, 1 ms) and may be used to carry a control and data transmission. As shown in FIG. 6, each resource unit of a big square in white represents a time-frequency resource for a candidate control and data transmission. Each resource unit of a big square in gray represents a time-frequency resource for an actual control and data transmission. Specifically, a big square resource unit in white may be used for a candidate data transmission including a control transmission (e.g., SCI) , and a big square resource unit in gray may be used for an actual data transmission including a control transmission (e.g., SCI) .

A resource unit of a small rectangle represents a frequency domain resource (e.g., a resource block) *time domain resource (e.g., a symbol) . As shown in FIG. 6, each small rectangle resource unit in white, black, or diagonal stripes represents a time-frequency resource unit which may be used to carry SCI for UE blind detection. A small rectangle resource unit in white represents a time-frequency resource for candidate control transmission. A small rectangle resource unit in black represents a time-frequency resource for control transmission being blind detected. A small rectangle resource unit of diagonal stripes represents a time-frequency resource for actual control transmission.

SCI carried in a small rectangle resource unit may include resource reservation information to indicate a reserved resource for a different TB transmitted in a subsequent transmission interval (e.g., in subsequent ON duration of a DRX cycle) . The resource (s) reserved for a subsequent TB (e.g., TB2 as shown and illustrated in FIG. 3) occupy the same number of resource units as those of the actual data transmissions in the current TB (e.g., TB1 as shown and illustrated in FIG. 3) .

In the embodiments of FIG. 6, a Rx UE receives actual data transmissions in two big square resource units in gray in 1 ^st ON duration within 1 ^st DRX cycle. The actual data transmissions include a control transmission (e.g., SCI) that is marked with diagonal stripes. After receiving these actual data transmissions, the Rx UE can know, from the control transmission, two resource units that are reserved for a different TB transmitted in a subsequent ON duration (i.e., 2 ^nd ON duration) of another DRX cycle.

As shown in FIG. 6, two big square resource units in gray in the 2 ^nd ON duration represent these two reserved resource units. That is to say, based on the control transmission, the Rx UE may only perform blind detection on these two reserved resource unit (i.e., big square resource units in gray in the 2 ^nd ON duration) , to save power, instead of performing blind detection on all 24 candidate resource units of the 2 ^nd ON duration.

Solution 2

In some embodiments of the present disclosure, a Rx UE may be configured with a maximum detection number per a resource pool. In an embodiment, a resource pool is configured to only detect SCI or data transmission transmitted on a reserved resource after detecting an initial transmission of a certain TB in this resource pool, for power reduction of a UE. The configuration information may be indicated or delivered, from a network or a Tx UE, to a Rx UE. A specific example is described in FIG. 7.

In some other embodiments of the present disclosure, a Rx UE may be configured with a maximum detection number per DRX configuration. In an embodiment, a DRX configuration is configured as only detecting SCI or data transmission transmitted on a reserved resource after detecting an initial transmission of a certain TB in on-duration of a DRX cycle, for power reduction of a UE. The configuration information may be indicated or delivered, from a network or a Tx UE, to a Rx UE.

The embodiments of FIG. 7 also show big square resource units in white or gray and small rectangle resource units in white, black, or diagonal stripes, and these time-frequency resource units are similar to those in the embodiments of FIG. 6.

There may be multiple continuous or non-continuous time-frequency resource units in a resource pool, as shown in FIG. 7. The embodiments of FIG. 7 assumes that the resource pool is configured to only detect SCI or data transmission transmitted on a reserved resource after detecting an initial transmission of a certain TB in this resource pool, for power reduction of a Rx UE.

In particular, in the embodiments of FIG. 7, a Rx UE blind detects small rectangle resource units in black; after detecting an initial transmission of a TB (i.e., two big square resource units in gray) by blind detection, the Rx UE determines a reserved resource that is indicated by the small rectangle resource unit of diagonal stripes in the detected two big square resource units in gray; and then, the Rx UE only detects SCI or data transmission transmitted on the reserved resource according to the resource pool configuration.

Solution 3

In some embodiments of the present disclosure, a Tx UE can indicate the other UE (e.g., a Rx UE) in SCI whether the Rx UE only detect a subsequent sidelink control transmission or a subsequent sidelink data transmission on a reserved resource. The SCI can include a field (e.g., 1 bit) to indicate whether a Rx UE only detects a reserved resource for a subsequent sidelink control or data transmission. These embodiments can be further combined with the embodiments of FIGS. 6 and 7. i.e., further based on resource pool configuration and/or DRX configuration.

For example, in the field of the SCI, ‘1’ of the bit represents a Rx UE only detecting the sidelink control or data transmission on a reserved resource, and ‘0’ of the bit represents the Rx UE performing blind detection on each candidate resource, i.e., not only detecting the sidelink control or data transmission on a reserved resource; and vice versa.

Solution 4

In some embodiments of the present disclosure, in NR V2X mode 2, a UE performs autonomous resource selection, and a reserved resource may be pre-empted by the other UEs. If a Rx UE only detects SCI and data transmission on a reserved source, it may miss a transmission on a re-selected resource transmitted from a Tx UE. When a Tx UE detects that the reserved resource is pre-empted (by a UE different from the Tx UE and the Rx UE) , the Tx UE will perform resource reselection for a subsequent transmission. To solve the pre-emption issue in NR V2X mode 2, a resource pattern or a candidate resource set can be configured in these embodiments.

In an embodiment, the resource pattern is associated with reserved resource (s) in the same on duration of a DRX cycle. According to the resource pattern, the Rx UE will detect a set of resources in the resource pattern, to receive the excepted transmission. For example, the resource pattern indicates same frequency resource in multiple time slots, or multiple frequency resources in the same time slots, or a time-frequency region associated with reserved resource (s) . A specific example is described in FIG. 8.

In a further embodiment, a set of resource (s) can be a candidate resource set based on sensing result (s) of a Tx UE. The candidate resource set may be transmitted to a Rx UE by higher layer signalling in data information. A specific example is described in FIG. 9.

The embodiments of FIG. 8 also show big square resource units in white or gray and small rectangle resource units in white, black, or diagonal stripes, and these time-frequency resource units are similar to those in the embodiments of FIG. 6. The embodiments of FIG. 8 further show 1 ^st DRX cycle, 1 ^st ON duration, and 2 ^nd ON duration, which have similar configurations to those in the embodiments of FIG. 6.

In the embodiments of FIG. 8, according to a resource pattern, a Rx UE will only detect a set of resources based on the resource pattern in the 2 ^nd ON duration, to receive the excepted transmission (s) , instead of performing blind detection on all 24 candidate resource units of the 2 ^nd ON duration. For example, a resource pattern is configured as including same frequency resource in multiple time slots, multiple frequency resources in the same time slots, or a time-frequency region associated with reserved resource.

In particular, after a Rx UE blind detects all small rectangle resource unit in black in the 1 ^st ON duration, the Rx UE determines a reserved resource that is indicated by a small rectangle resource unit of diagonal stripes in the detected two big square resource units in gray in the 1 ^st ON duration. Then, the Rx UE determines to detect a set of resources based on a resource pattern to perform a subsequent blind detection. After detecting the set of resources based on the resource pattern, the Rx UE may receive a transmission on an actual transmission resource.

In the embodiments of FIG. 8, the resource pattern is configured as including the same frequency resource in two time slots and the same time resource in four frequency resources. The set of resources based on the resource pattern includes small rectangle resource units in black in the 2 ^nd ON duration as shown in FIG. 8. That is to say, the set of resources based on the resource pattern is configured based on a reserved resource, which is indicated by a small rectangle resource unit of diagonal stripes in the 1 ^st ON duration.

The embodiments of FIG. 8 show that the actual transmission resource is different from the reserved resource, which is indicated by the resource unit in the 1 ^st ON duration. In some other embodiments, the actual transmission resource is the same as the reserved resource indicated by the resource unit in the 1 ^st ON duration. That is to say, a subsequent transmission is actually transmitted on the reserved resource indicated by the resource unit in the 1 ^st ON duration.

The embodiments of FIG. 9 also show big square resource units in white or gray and small rectangle resource units in white, black, or diagonal stripes, and these time-frequency resource units are similar to those in the embodiments of FIG. 6. The embodiments of FIG. 9 further show 1 ^st DRX cycle, 1 ^st ON duration, and 2 ^nd ON duration, which have similar configurations to those in the embodiments of FIG. 6.

In the embodiments of FIG. 9, according to a configured candidate resource set, a Rx UE will only detect a set of resources based on the candidate resources set in the 2 ^nd ON duration for receiving the excepted transmission (s) , instead of performing blind detection on all 24 candidate resource units of the 2 ^nd ON duration.

For example, a candidate resource set may be configured based on sensing result (s) of a Tx UE, and the Tx UE indicates the candidate resource set to a Rx UE. A candidate resource can be transmitted to the Rx UE by higher layer signalling in data information.

In particular, after a Rx UE blind detects all small rectangle resource unit in black in the 1 ^st ON duration, the Rx UE determines reserved resource (s) that are indicated by a small rectangle resource unit of diagonal stripes in the detected two big square resource units in gray in the 1 ^st ON duration. Then, the Rx UE performs subsequent blind detection in the configured candidate resource set in the 2 ^nd ON duration as well as the reserved resource (s) which are indicated by the resource unit in the 1 ^st ON duration. After completing the subsequent blind detection in the 2 ^nd ON duration, the Rx UE may receive a transmission on an actual transmission resource.

The embodiments of FIG. 9 show that the configured candidate resource set in the 2 ^nd ON duration includes small rectangle resource units in black. A control transmission in the reserved resources (which are indicated by resource units in the 1 ^st ON duration) is also a small rectangle resource unit in black as shown in FIG. 9. In one example, the configured candidate resource set includes the reserved resource (s) indicated by the resource unit in the 1 ^st ON duration. In another example, the configured candidate resource set does not include the reserved resource (s) indicated by the resource unit in the 1 ^st ON duration.

FIG. 9 shows that actual transmission resources are two big square resource units in gray in the 2 ^nd ON duration, and a control transmission (e.g., SCI) in the actual transmission resources is carried in a small rectangle resource unit of diagonal stripes. In the embodiments of FIG. 9, the actual transmission resources are different from the reserved resources indicated by the resource unit in the 1 ^st ON duration. In some other embodiments, the actual transmission resources are the same as the reserved resource (s) that are indicated by the resource unit in the 1 ^st ON duration. That is to say, a subsequent transmission is actually transmitted on the reserved resource (s) that are indicated by the resource unit in the 1 ^st ON duration.

Solution 5

In some embodiments of the present disclosure, each DRX configuration includes a field to indicate a set of resources in time and/or frequency domain. This set of resource can be a candidate resource set which is determined based on sensing result (s) of a Tx UE. This set of resource can limit a blind detection time and/or frequency domain region for a Rx UE, and this region may carry an initial transmission and/or a subsequent transmission on reserved resource (s) .

For a Rx UE, if the DRX configuration is indicated or configured, the Rx UE is not expected to detect the control and/or data transmission or receive the transmission out of the indicated time and/or frequency domain region. A specific example is described in FIG. 10. The difference between the embodiments of FIG. 10 and the embodiments of FIG. 9 is that, the candidate resource set in the embodiments of FIG. 10 is configured combined with DRX configuration (s) .

The embodiments of FIG. 10 also show big square resource units in white or gray and small rectangle resource units in white, black, or diagonal stripes, and these time-frequency resource units are similar to those in the embodiments of FIG. 6. The embodiments of FIG. 10 further show 1 ^st DRX cycle, 1 ^st ON duration, and 2 ^nd ON duration, which have similar configurations to those in the embodiments of FIG. 6.

In the embodiments of FIG. 10, according to a configured candidate resource set, a Rx UE will only perform blind detection a set of resources based on the candidate resources set in both the 1 ^st ON duration and the 2 ^nd ON duration for receiving transmission (s) , instead of performing blind detection on all 24 candidate resource units of the 1 ^st ON duration or the 2 ^nd ON duration.

In particular, according to the embodiments of FIG. 10, after a Rx UE blind detects a configured candidate resources set in the 1 ^st ON duration (as shown as small rectangle resource units in black) , the Rx UE determines a reserved resource (s) that are indicated by a small rectangle resource unit of diagonal stripes in the detected two big square resource units in gray in the 1 ^st ON duration. Then, the Rx UE performs subsequent blind detection in a configured candidate resource set in the 2 ^nd ON duration as well as the reserved resource (s) which are indicated by resource unit in the 1 ^st ON duration. After the subsequent blind detection in the 2 ^nd ON duration, the Rx UE may receive a transmission on an actual transmission resource.

The embodiments of FIG. 10 show that the configured candidate resource set in the 2 ^nd ON duration includes the reserved resource (s) indicated by the resource unit in the 1 ^st ON duration. In some other embodiments, the configured candidate resource set in the 2 ^nd ON duration does not include the reserved resource (s) indicated by the resource unit in the 1 ^st ON duration.

Solution 6

In some embodiments of the present disclosure, if a Rx UE is indicated or configured one or more DRX configurations (i.e., one or more pieces of DRX configuration information) and one or more on-durations of these one or more DRX configurations are aligned or overlapped, the Rx UE performs blind detection until the Rx UE receives all initial transmissions from different Tx UEs for these one or more DRX configurations.

In other words, if there are one or more DRX configurations for one or more Tx UEs, the Rx UE not only detects a sidelink control and/or data transmission on reserved resource (s) , but also detects non-reserved resource (s) until a total number of all received initial transmissions reaches an expected or maximum number of initial transmissions. After a total number of the received initial transmissions reaches the expected or maximum number, the Rx UE may only detect subsequent sidelink control and/or data transmission (s) on reserved resource (s) .

These embodiments of one or more DRX configurations may include the following two cases.

Case 1

In Case 1, a Rx UE is aware of an expected number of initial transmissions during one or more on-durations. The expected number of initial transmissions represents the maximum number of initial transmissions during the one or more on-durations. These one or more on-durations may be indicated by one or more DRX configurations transmitted from one or more Tx UEs. Theses on-durations may be aligned or overlapped. A specific example is described in FIG. 11.

In some embodiments under Case 1, an expected or maximum number of initial transmissions during an on-duration can be configured in DRX configuration. The DRX configuration may be transmitted from a Tx UE or a network. In one example under Case 1, two or more expected or maximum numbers of initial transmissions are configured to a Rx UE by more than one DRX configurations from more than one Tx UEs.

Based on the configured two or more expected or maximum numbers, a Rx UE may determine an actual maximum number of initial transmissions during one or more on-durations indicated by one or more DRX configurations transmitted from one or more Tx UEs.

For one example, a Rx UE computes a sum of all configured two or more expected or maximum numbers, as the actual maximum number. Then, the Rx UE performs blind detection on reserved resource (s) and non-reserved resource (s) until a total number of received initial transmissions reaches the sum. After completing the blind detection, the Rx UE only detects subsequent sidelink control and/or data transmission (s) on reserved resource (s) . In other words, if a total number of the received initial transmissions are less the sum, the Rx UE performs blind detection on all the resources to receive remaining initial transmissions. Once a total number of the received initial transmissions is equal to the sum, the Rx UE stops the blind detection and will only detect on reserved resource (s) .

For another example, a Rx UE computes an average value of all configured two or more expected or maximum numbers, as the actual maximum number. Then, the Rx UE performs blind detection on reserved resource (s) and non-reserved resource (s) until a total number of received initial transmissions reaches the average value. Once a total number of the received initial transmissions is equal to the average value, the Rx UE stops the blind detection and will only detect on reserved resource (s) .

Case 2

In Case 2, a Rx UE is not aware of an expected or maximum number of initial transmissions during an on-duration of a DRX cycle. A Tx UE may transmit an indicator in SCI, to indicate the expected or maximum number. Upon detecting the SCI transmitted by the Tx UE, a Rx UE may know the expected or maximum number. In particular, two or more Tx UEs may transmit, to a Rx UE, two or more expected or maximum numbers of initial transmissions in SCI. Specific operations of receiving SCI in Case 2 are similar to those in the embodiments of Solution 3, as described above.

Based on the received two or more expected or maximum numbers, the Rx UE may determine an actual maximum number of initial transmissions during one or more on-durations indicated by one or more DRX configurations transmitted from one or more Tx UEs. For one example, a Rx UE computes a sum of all received two or more expected or maximum numbers, as the actual maximum number. For another example, a Rx UE computes an average value of all received two or more expected or maximum numbers, as the actual maximum number. The following operations of the Rx UE after computing the sum or the average value in Case 2 are similar to those described in Case 1.

The embodiments of FIG. 11 also show big square resource units in white or gray and small rectangle resource units in white, black, or diagonal stripes, and these time-frequency resource units are similar to those in the embodiments of FIG. 6. The embodiments of FIG. 11 further show 1 ^st DRX cycle, 1 ^st ON duration, and 2 ^nd ON duration, which have similar configurations to those in the embodiments of FIG. 6. In addition, the embodiments of FIG. 11 show 3 ^rd ON duration and 2 ^nd DRX cycle including the 2 ^nd ON duration, which have similar configurations.

The embodiments of FIG. 11 assume that an expected or maximum number of initial transmissions during an on-duration of a DRX cycle is configured to 2. After performing blind detection in 1 ^st ON duration of 1 ^st DRX cycle, a Rx UE receives 1 initial transmission (i.e., two big square resource units in gray in 1 ^st ON duration) . As shown in FIG. 11, SCI included in the initial transmission detected in the 1 ^st ON duration indicates reserved resources in 2 ^nd ON duration of 2 ^nd DRX cycle (i.e., two big square resource units in gray in 2 ^nd ON duration) . Moreover, SCI included in the reserved resources in 2 ^nd ON duration indicates reserved resources in 3 ^rd ON duration (i.e., two big square resource units in gray in 3 ^rd ON duration) .

However, since the total number of detected initial transmission is less than the configured expected or maximum number of initial transmissions, i.e., 1 < 2, the Rx UE continues to perform blind detection in all candidate resource units of the 2 ^nd ON duration, instead of only detecting on the reserved resources in 2 ^nd ON duration of 2 ^nd DRX cycle (which are indicated by the SCI in the initial transmission detected in the 1 ^st ON duration) .

After performing blind detection in the 2 ^nd ON duration, the Rx UE receives another initial transmission (i.e., one big square resource unit in gray in 2 ^nd ON duration) . As shown in FIG. 11, SCI included in the initial transmission detected in the 2 ^nd ON duration indicates a reserved resource in 3 ^rd ON duration (i.e., one big square resource unit in gray in 3 ^rd ON duration) . Since the total number of detected initial transmission is equal to the configured expected or maximum number of initial transmissions, i.e., 2 = 2, the Rx UE starts to only detect subsequent sidelink control and/or data transmission on reserved resource (s) in 3 ^rd ON duration.

Solution 7

In some embodiments of the present disclosure, based on a current resource reservation field in SCI, an initial transmission of a TB can indicate two or three reserved resources in window W (e.g., window "W1" or W2 illustrated and shown in FIG. 3) . The SCI can include a field (e.g., 1 bit) to indicate whether the reserved resource (s) in window W is used for a target Rx UE (destination UE of this transmission) detection or used for a Tx UE sidelink transmission of current TB.

For instance, ‘1’ of the bit of the field in SCI represents that a reserved resource (s) in window W may be used for a Tx UE sidelink transmission of a current TB, ‘0’ of the bit represents that the reserved resource (s) in window W may be used for a target Rx UE detection, and vice versa.

If the field in SCI represents that a reserved resource (s) in window W is used for a Tx UE sidelink transmission of a current TB, other Tx UE (s) should avoid selecting this resource for their sidelink transmission.

If the field in SCI represents that the reserved resource in window W is used for a target Rx UE detection, a target Rx UE, who is the destination UE of this transmission, should detect multiple indicated resources for receiving sidelink transmission (s) , e.g., in an on-duration of a DRX cycle. In this scenario, other Tx UE (s) can select this reserved resource for their sidelink transmission. For example, other Tx UE (s) can select this reserved resource for their sidelink transmission when a priority level of their transmitted traffic is higher than a (pre-) configured priority level threshold. The priority level threshold can be configured per a resource pool and/or per DRX configuration (s) .

FIG. 12 illustrates an exemplary block diagram of an apparatus 1200 according to an embodiment of the present disclosure. In some embodiments of the present disclosure, the apparatus 1200 may be a UE (e.g., a Rx UE) , which can at least perform the method illustrated in FIG. 4.

As shown in FIG. 12, the apparatus 1200 may include at least one receiver 1202, at least one transmitter 1204, at least one non-transitory computer-readable medium 1206, and at least one processor 1208 coupled to the at least one receiver 1202, the at least one transmitter 1204, and the at least one non-transitory computer-readable medium 1206.

Although in FIG. 12, elements such as receiver 1202, transmitter 1204, non-transitory computer-readable medium 1206, and processor 1208 are described in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. In some embodiments of the present disclosure, the at least one receiver 1202 and the at least one transmitter 1204 are combined into a single device, such as a transceiver. In certain embodiments of the present disclosure, the apparatus 1200 may further include an input device, a memory, and/or other components.

In some embodiments of the present disclosure, the at least one non-transitory computer-readable medium 1206 may have stored thereon computer-executable instructions which are programmed to implement the operations of the methods, for example as described in view of FIG. 4, with the at least one receiver 1202, the at least one transmitter 1204, and the at least one processor 1208.

FIG. 13 illustrates an exemplary block diagram of an apparatus 1300 according to another embodiment of the present disclosure. In some embodiments of the present disclosure, the apparatus 1300 may be a UE (e.g., a Tx UE) , which can at least perform the method illustrated in FIG. 5.

As shown in FIG. 13, the apparatus 1300 may include at least one receiver 1302, at least one transmitter 1304, at least one non-transitory computer-readable medium 1306, and at least one processor 1308 coupled to the at least one receiver 1302, the at least one transmitter 1304, and the at least one non-transitory computer-readable medium 1306.

Although in FIG. 13, elements such as receiver 1302, transmitter 1304, non-transitory computer-readable medium 1306, and processor 1308 are described in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. In some embodiments of the present disclosure, the at least one receiver 1302 and the at least one transmitter 1304 are combined into a single device, such as a transceiver. In certain embodiments of the present disclosure, the apparatus 1300 may further include an input device, a memory, and/or other components.

In some embodiments of the present disclosure, the at least one non-transitory computer-readable medium 1306 may have stored thereon computer-executable instructions which are programmed to implement the operations of the methods, for example as described in view of FIG. 5, with the at least one receiver 1302, the at least one transmitter 1304, and the at least one processor 1308.

Those having ordinary skills in the art would understand that the operations of a method described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. Additionally, in some aspects, the operations of a method may reside as one or any combination or set of codes and/or instructions on a non-transitory computer-readable medium, which may be incorporated into a computer program product.

While this disclosure has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations may be apparent to those skilled in the art. For example, various components of the embodiments may be interchanged, added, or substituted in the other embodiments. Also, all of the elements of each figure are not necessary for operation of the disclosed embodiments. For example, those having ordinary skills in the art would be enabled to make and use the teachings of the disclosure by simply employing the elements of the independent claims. Accordingly, embodiments of the 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 disclosure.

In this document, the terms "includes, " "including, " or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that includes 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 includes the element. Also, the term "another" is defined as at least a second or more. The term "having" and the like, as used herein, are defined as "including. "

Claims

A method for sidelink communications, comprising:

receiving sidelink configuration information;

performing blind detection in a configured time and frequency resource region;

receiving, in the configured time and frequency resource region, a first sidelink transmission including sidelink control information (SCI) ; and

performing sidelink transmission detection in a target time and frequency resource region according to at least one of the sidelink configuration information and the SCI in the first sidelink transmission.
The method of Claim 1, wherein the sidelink configuration information is received from one of a network, a base station (BS) , and a sidelink transmission user equipment (UE) .
The method of Claim 1, wherein the sidelink configuration information includes resource pool configuration information, and the resource pool configuration information includes a field to indicate whether to only perform the sidelink transmission detection in the target time and frequency resource region.
The method of Claim 1, wherein the configured time and frequency resource region is a resource pool.
The method of Claim 1, wherein the sidelink configuration information includes discontinuous reception (DRX) configuration information, and the DRX configuration information includes a field to indicate whether to only perform the sidelink transmission detection in the target time and frequency resource region.
The method of Claim 1, wherein the configured time and frequency resource region is an on-duration of a DRX cycle.
The method of Claim 1, wherein the SCI in the first sidelink transmission includes a field, and the field indicates whether to only perform the sidelink transmission detection in the target time and frequency resource region.
The method of Claim 7, wherein the field includes 1 bit, one of values ‘1’ and ‘0’ of the bit represents only performing the sidelink transmission detection in the target time and frequency resource region, and the other one of values ‘1’ and ‘0’ of the bit represents performing blind detection in the target time and frequency resource region and one or more other resources.
The method of Claim 1, further comprising:

receiving a second sidelink transmission in the target time and frequency resource region, wherein the second sidelink transmission includes at least one of a control transmission and a data transmission.
The method of Claim 9, wherein each of the first sidelink transmission and the second sidelink transmission is an initial transmission of a transport block.
The method of Claim 1, wherein the target time and frequency resource region includes a reserved resource, and the reserved resource is indicated by the SCI in the first sidelink transmission.
The method of Claim 11, wherein the target time and frequency resource region further includes one or more non-reserved resources.
The method of Claim 12, wherein locations of the one or more non-reserved resources in time and frequency domain are associated with a location of the reserved resource in the time and frequency domain.
The method of Claim 13, wherein a location relation between the location of the reserved resource in the time and frequency domain and the locations of the one or more non-reserved resources in the time and frequency domain is pre-configured or configured.
The method of Claim 12, wherein the target time and frequency resource region is a candidate resource set, the candidate resource set includes the reserved resource and the one or more non-reserved resources.
The method of Claim 15, wherein the candidate resource set is based on a sensing result of a sidelink transmission UE.
The method of Claim 15, wherein the candidate resource set is pre-configured or configured.
The method of Claim 1, wherein the configured time and frequency resource region is a subset of resources within an on-duration of a DRX cycle.
The method of Claim 18, wherein the subset of resources is configured by DRX configuration information included in the sidelink configuration information.
The method of Claim 18, wherein the subset of resource is based on a sensing result of a sidelink transmission UE.
The method of Claim 1, wherein the sidelink configuration information includes one or more pieces of DRX configuration information, and each of the one or more pieces of DRX configuration information includes an expected number of initial transmissions of a transport block.
The method of Claim 21, further comprising:

determining a total expected number of initial transmissions based on all the expected number of initial transmissions included in the sidelink configuration information.
The method of Claim 22, wherein the first sidelink transmission is an initial transmission of a transport block, and performing the sidelink transmission detection comprises:

performing the blind detection in the configured time and frequency resource region and receiving one or more initial transmissions of the transport block according to the total expected number of initial transmissions; and

after a total number of received initial transmissions of the transport block reaches to the total expected number, performing the sidelink transmission detection in the target time and frequency resource region.
The method of Claim 23, wherein the configured time and frequency resource region includes one or more on-durations indicated by the one or more pieces of DRX configuration information.
The method of Claim 1, further comprising:

receiving, in the configured time and frequency resource region, a third sidelink transmission including sidelink control information (SCI) ,

wherein the third sidelink transmission is a subsequent initial transmission of a transport block.
The method of Claim 25, wherein the SCI in the third sidelink transmission has the same format and functions as the SCI in the first sidelink transmission.
The method of Claim 1, wherein the SCI in the first sidelink transmission includes one or more reserved resources and a field, and the field indicates a usage of the one or more reserved resources.
The method of Claim 27, wherein the field includes 1 bit, one of values ‘1’ and ‘0’ of the bit represents that the one or more reserved resources are used for detecting an initial transmission and a re-transmission associated with the initial transmission, and the other one of values ‘1’ and ‘0’ of the bit represents that the one or more reserved resources are used for detecting an initial transmission.
A method for sidelink communications, comprising:

transmitting sidelink configuration information; and

transmitting a sidelink transmission including sidelink control information (SCI) ,

wherein at least one of the sidelink configuration information and the SCI indicates whether a sidelink reception user equipment (UE) only performs sidelink transmission detection in a target time and frequency resource region after the sidelink reception UE receives the sidelink transmission.
The method of Claim 29, wherein the sidelink configuration information is received from one of a network and a base station (BS) .
The method of Claim 30, wherein the sidelink configuration information includes resource pool configuration information, and the resource pool configuration information includes a field to indicate whether the sidelink reception UE only performs the sidelink transmission detection in the target time and frequency resource region.
The method of Claim 29, wherein the sidelink configuration information includes discontinuous reception (DRX) configuration information.
The method of Claim 32, wherein the DRX configuration information includes a field to indicate whether the sidelink reception UE only performs the sidelink transmission detection in the target time and frequency resource region.
The method of Claim 32, wherein the DRX configuration information includes an expected number of initial transmissions, and the expected number of initial transmissions indicates a total number of the sidelink transmission and one or more initial transmissions transmitted by a sidelink transmission UE.
The method of Claim 29, wherein the SCI in the sidelink transmission includes one or more reserved resources and a field, and the field indicates a usage of the one or more reserved resources.
The method of Claim 35, wherein the field includes 1 bit, one of values ‘1’ and ‘0’ of the bit represents that the one or more reserved resources are used for detecting an initial transmission and a re-transmission associated with the initial transmission, and the other one of values ‘1’ and ‘0’ of the bit represents that the one or more reserved resources are used for detecting an initial transmission.
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 cause the processor to implement the method of any of Claims 1-28.
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 cause the processor to implement the method of any of Claims 29-36.