Communication method, device and computer readable medium thereof

Abstract

Embodiments of this disclosure relate to communication methods, apparatus, and computer-readable media in wireless communication systems. In one embodiment of this disclosure, a communication method is performed at a receiving terminal device in sidelink communication. In this communication method, sidelink control information (SCI) is received from a transmitting terminal device, the SCI indicating the number of additional DMRS symbols for a sidelink data channel. Then, the duration of the sidelink data channel is determined based on the number of symbols within a time slot and the number of symbols for a sidelink feedback channel. Next, a DMRS pattern to be used for the sidelink data channel is determined based on the received number of additional DMRS symbols for the sidelink data channel and the determined duration of the sidelink data channel.

Description

TECHNICAL FIELD

[0001] The non-limiting and exemplary embodiments of the present disclosure generally relate to the field of wireless communication technology, and more particularly to a communication method, device and computer readable medium in a wireless communication system. BACKGROUND

[0002] This section introduces aspects that can be helpful in better understanding the present disclosure. Thus, the statements made herein are not to be construed as an admission that the prior art contains the content or that the prior art contains anything not contained in the prior art.

[0003] A new radio access system (also referred to as an NR system or an NR network) is a next generation communication system. The 3rd Generation Partnership Project (3GPP) working group has approved a study on the NR system. The NR system will target a single technical framework that can address all usage scenarios, requirements and deployment scenarios, including enhanced mobile broadband, massive machine type communication, ultra-reliable low latency communication, etc.

[0004] In order to improve data rate performance, a sidelink technology is introduced in the 3GPP long term evolution (LTE) which allows two adjacent LTE devices to communicate directly without going through a base station. Communications such as device-to-device (D2D) communication, vehicle-to-vehicle (V2V) communication, vehicle-to-everything (V2X) communication, etc. perform data transmission based on the sidelink technology.

[0005] In the NR system, sidelink solutions on the NR unlicensed band (NR-U) are studied. The NR system will support (pre)configuring one or more DMRS patterns for a physical sidelink shared channel (PSSCH), and an accurate DMRS pattern is indicated by a transmitter (TX) terminal device using sidelink control information (SCI). For mode 2, the DMRS pattern can be selected by the transmitting terminal device from the (pre)configured patterns of the resource pool. However, issues such as the number of DMRS patterns, the number of possible DMRS patterns, the way to determine the DMRS pattern to be used, and the way to indicate the DMRS pattern, etc. are still not resolved. SUMMARY

[0006] Generally, the example embodiments of the present disclosure provide a new communication solution in a wireless communication system.

[0007] According to a first aspect of the disclosure, a communication method is provided. The communication method can be performed at a receiving terminal device, and one of the purposes thereof is to provide improved DMRS transmission of a sidelink data channel. The communication method can comprise receiving, from a transmitting terminal device, sidelink control information (SCI) indicating a number of additional DMRS symbols of the sidelink data channel; determining a duration of the sidelink data channel according to a number of symbols within a slot and a number of symbols of a sidelink feedback channel; and determining a DMRS pattern to be used for the sidelink data channel based on the received number of additional DMRS symbols for the sidelink data channel and the determined duration of the sidelink data channel.

[0008] According to a second aspect of the disclosure, a communication method is provided. The communication method can be performed at a transmitting terminal device, and one of the purposes thereof is to provide improved DMRS transmission of a sidelink data channel. The communication method can comprise determining a duration of the sidelink data channel according to a number of symbols within a slot and a number of symbols of a sidelink feedback channel; determining a number of additional DMRS symbols; determining a DMRS pattern to be used for the sidelink data channel based on the determined number of additional DMRS symbols for the sidelink data channel and the determined duration of the sidelink data channel; and transmitting, to a receiving terminal device, sidelink control information (SCI) indicating the number of additional DMRS symbols for the sidelink data channel.

[0009] According to a third aspect of the disclosure, a terminal device is provided. The terminal device can be, for example, a receiving network device in sidelink communication. The terminal device can comprise at least one processor and at least one memory coupled with the at least one processor. The at least one memory has computer program code stored therein, which computer program code is configured to, when executed on the at least one processor, cause the terminal device to perform operations of any of the first aspect.

[0010] According to a fourth aspect of the disclosure, another terminal device is provided. The another terminal device can be, for example, a transmitting network device in sidelink communication. The terminal device can comprise at least one processor and at least one memory coupled with the at least one processor. The at least one memory has computer program code stored therein, which computer program code is configured to, when executed on the at least one processor, cause the terminal device to perform operations of any of the second aspect.

[0011] According to a fifth aspect of the disclosure, a computer-readable storage medium having stored thereon a computer program, which computer program, when executed by at least one processor of a device, causes the device to perform actions in the method according to any embodiment of the first aspect.

[0012] According to a sixth aspect of the disclosure, there is provided a computer- readable storage medium having stored thereon a computer program, which, when executed by at least one processor of a device, causes the device to perform the actions in the method according to any embodiment in the second aspect.

[0013] According to a seventh aspect of the disclosure, there is provided a computer program product comprising the computer-readable storage medium according to the fifth aspect.

[0014] According to an eighth aspect of the disclosure, there is provided a computer program product comprising the computer-readable storage medium according to the sixth aspect. BRIEF DESCRIPTION OF DRAWINGS

[0015] The above and other aspects, features, and benefits of various embodiments of the present disclosure will be apparent from the detailed description, the drawings, and the appended claims taken in conjunction with the available prior art. Although embodiments of the present disclosure are described in sufficient detail to enable one of ordinary skill in the art to make and use the embodiments, it should be understood that various changes, substitutions, and alterations can be made herein without departing from the scope of the present disclosure. For example, while embodiments of the present disclosure are described in the context of a single device, it should be understood that embodiments of the present disclosure can be implemented in a plurality of devices. It should also be understood that the various embodiments of the present disclosure can be implemented in a variety of devices, systems, and methods.

[0016] Figure 1 A communication method at a receiving terminal device according to embodiments of the present application is shown;

[0017] Figure 2A And Figure 2B An example method for determining a duration of a physical sidelink shared channel (PSSCH) according to embodiments of the present disclosure is shown;

[0018] Figure 3 Parameter configurations for different subcarrier spacings are shown;

[0019] Figure 4 An example DMRS pattern mapping table according to embodiments of the present disclosure is shown;

[0020] Figure 5 Another example DMRS pattern mapping table according to embodiments of the present disclosure is shown;

[0021] Figure 6 Yet another example DMRS pattern mapping table according to embodiments of the present disclosure is shown;

[0022] Figure 7 Yet another example DMRS pattern mapping table according to embodiments of the present disclosure is shown;

[0023] Figure 8 Yet another example DMRS pattern mapping table according to embodiments of the present disclosure is shown;

[0024] Figure 9 A communication method at a transmitting terminal device according to embodiments of the present disclosure is shown; and

[0025] Figure 10 A simplified block diagram of a communication system 1000 is schematically illustrated, which can implement the communication solution according to embodiments of the present disclosure. DETAILED DESCRIPTION

[0026] In the following, the solutions provided in the present disclosure are described in detail by embodiments in conjunction with the drawings. It should be understood that these embodiments are given only to enable those skilled in the art to better understand and implement the present disclosure, and do not limit the scope of the present disclosure in any way. For example, features shown or described as part of one embodiment can be used with another embodiment to create yet another embodiment. All features described in the present specification can not be described in actual implementation.

[0027] In the drawings, various embodiments of the present disclosure are shown in block diagrams, flowcharts and other diagrams. Each block in the flowchart or block diagram can represent a module, program or code segment containing one or more executable instructions for performing a specific logical function, and in the present disclosure, optional blocks are indicated with dashed lines. In addition, although these blocks are described in a specific order to perform the method steps, in fact, they do not necessarily be strictly executed in the order described. For example, they can be executed in reverse order or simultaneously, depending on the nature of the corresponding operations. It should also be noted that each block in the block diagram and / or flowchart and its combination can be implemented by a special hardware-based system for performing the specified functions / operations or by a combination of special hardware and computer instructions.

[0028] The reference in the specification to "one embodiment", "an embodiment", "example embodiment" etc. means that a described embodiment can include a particular feature, structure, or characteristic, but every embodiment can not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of those skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0029] It should be understood that although the terms "first" and "second" and the like can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed terms.

[0030] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a," "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "has," "having," "includes" and / or "including" when used herein, specify the presence of stated features, elements and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0031] As used herein, the term "wireless communication network" refers to a network that complies with any suitable wireless communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), etc. A "wireless communication network" can also be referred to as a "wireless communication system". Furthermore, communication between network devices in a wireless communication network, between a network device and a terminal device, or between terminal devices can be performed according to any suitable communication protocol, including but not limited to Global System for Mobile Communications (GSM), Universal Mobile Telecommunication System (UMTS), Long Term Evolution (LTE), New Radio (NR), Wireless Local Area Network (WLAN) standards such as IEEE 802.11 standards, and / or any other appropriate wireless communication standard known presently or developed in the future.

[0032] As used herein, the term "network device" refers to a node in a wireless communication network via which terminal devices access the network and receive services therefrom. A network device can refer to a base station (BS) or an access point (AP), e.g., a NodeB (or NB), an evolved NodeB (eNodeB or eNB), a NR NB (also known as gNB), a remote radio unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, a low power node (such as femto, pico, etc.), depending on the terminology used and technology.

[0033] As used herein, the term "terminal device" refers to any device having wireless or wired communication capabilities. Examples of terminal devices include, but are not limited to, a user equipment (UE), a personal computer, a desktop computer, a mobile computer, a cell phone, a cellular phone, a smart phone, a personal digital assistant (PDA), a portable computer, a tablet computer, a wearable device, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, a machine type communication (MTC) device, a vehicle mounted device for V2X communication (where X denotes a pedestrian, a vehicle, or infrastructure / network), or an image capture device such as a digital camera, a gaming device, a music storage and playback appliances, or an Internet appliance supporting wireless or wired Internet access and browsing, etc.

[0034] In one embodiment, a terminal device can be connected with a first network device and a second network device. One of the first network device and the second network device can be a master node and the other can be a secondary node. The first network device and the second network device can use different radio access technologies (RATs). In one embodiment, the first network device can be a first RAT device and the second network device can be a second RAT device. In one embodiment, the first RAT device is an eNB and the second RAT device is a gNB. Information related to different RATs can be transmitted from at least one of the first network device and the second network device to the terminal device. In one embodiment, first information can be transmitted from the first network device to the terminal device and second information can be transmitted from the second network device to the terminal device directly or via the first network device. In one embodiment, information related to a configuration of the terminal device configured by the second network device can be transmitted from the second network device via the first network device. Information related to a reconfiguration of the terminal device configured by the second network device can be transmitted to the terminal device directly or via the first network device from the second network device.

[0035] As yet another example, in an Internet of Things (IOT) scenario, a terminal device can represent a machine or other device that performs monitoring and / or measurements and transmits the results of such monitoring and / or measurements to another terminal device and / or a network device. In this case, the terminal device can be a machine-to-machine (M2M) device, which can be referred to as a machine-type communications (MTC) device in a 3GPP context. As one particular example, a terminal device can be a UE implementing the 3GPP Narrow Band Internet of Things (NB-IoT) standards. Examples of such machines or devices are sensors, metering devices such as electricity meters, industrial machinery, or home or personal appliances, e.g., a refrigerator, a television, a personal wearable device such as a watch, etc. In other scenarios, a terminal device can represent a vehicle or other equipment capable of monitoring and / or reporting its operational status or other functions associated with its operation.

[0036] As used herein, a downlink (DL) transmission refers to a transmission from a network device to a UE or from a network device as a parent node to another network device as a child node, while an uplink (UL) transmission refers to a transmission in the opposite direction.

[0037] In the NR system, issues such as the number of DMRS patterns, possible DMRS patterns, the way to determine the DMRS pattern to be used, and the way to indicate the DMRS pattern, etc. are still not resolved. Therefore, there is a need for some enhanced communication systems for DMRS pattern transmission in the NR system.

[0038] Embodiments of the present disclosure provide a new communication solution, and one of the purposes is to provide improved DMRS pattern transmission. In some embodiments of the present disclosure, a transmitting terminal device transmits SCI to a receiving terminal device to indicate the number of additional DMRS symbols of a sidelink data channel. The receiving terminal device can determine the duration of the sidelink data channel according to the number of symbols within a slot and the number of symbols of a sidelink feedback channel, and determine the DMRS pattern to be used based on the received SCI of the sidelink data channel and the determined duration. In this way, the DMRS pattern to be used in the sidelink data channel can be determined.

[0039] In the following, the solution proposed by the present disclosure will be described in detail in combination with the drawings. However, it should be understood that the following embodiments are for illustrative purposes only, and the present disclosure is not limited thereto. In addition, the solution provided herein can be used in the NR system or any other communication with similar problems.

[0040] Firstly, reference is made to Figure 1 An example communication method according to embodiments of the present application is described. The communication method can be performed at a receiving terminal device in a sidelink communication.

[0041] As Figure 1 indicated, in block 110, the receiving terminal device can receive, from a transmitting terminal device, sidelink control information (SCI) indicating the number of additional DMRS symbols of a sidelink data channel. The number of additional DMRS symbols for the sidelink data channel is determined by the transmitting terminal device and is notified by the SCI using, for example, two bits.

[0042] In step 120, the receiving terminal device can determine the duration of the sidelink data channel according to the number of symbols within a slot and the number of symbols for a sidelink feedback channel. In response to the reception of the SCI, the receiving terminal device can further determine the duration of the sidelink data channel.

[0043] In some embodiments of the present disclosure, the terminal device can determine the maximum number of symbols of the sidelink data channel within the slot as the duration of the sidelink data channel without considering the sidelink control channel. In other words, for the subchannel(s) containing the sidelink control channel and the subchannel(s) not containing the sidelink control channel respectively, the duration of the sidelink data channel can be determined as the number of symbols available for the sidelink data channel within the slot without the PSCCH.

[0044] Next, an example method for determining the duration of a physical sidelink shared channel (PSSCH) according to embodiments of the present disclosure is described with reference to Figure 2A

[0045] As shown in Figure 2A , in a slot with 14 symbols, there are symbols for automatic gain control (AGC), a guard gap, a physical sidelink feedback channel (PSFCH), AGC for the PSFCH, a gap for the PSFCH. According to embodiments of the present disclosure, the duration of the PSSCH D_PSSCH can be determined as

[0046] D_PSSCH = N_Symb - N_AGC - N_Gap - N_PSFCH - N_PSFCH_AGC - N_PSFCH_Gap (Equation 1)

[0047] wherein

[0048] N_Symb represents the total number of OFDM symbols in the slot for the PSSCH;

[0049] N_AGC represents the number of symbols in the slot for the AGC;

[0050] N_Gap represents the number of symbols in the slot for the guard gap;

[0051] N_PSFCH represents the number of symbols in the slot for the PSFCH;

[0052] N_PSFCH_AGC represents the number of symbols in the slot for the AGC of the PSFCH; and

[0053] N_PSFCH_Gap represents the number of symbols in the slot for the gap of the PSFCH.

[0054] ​As the total number of OFDM symbols for PSSCH in a slot, N_Symb can be equal to 14 for normal cyclic shift, while N_Symb can be equal to 12 for extended cyclic shift on intelligent transport system (ITS) dedicated carrier, and is (pre)configured in case of sidelink shared carrier with Uu interface communication (i.e. those communications over network equipment). The number N_AGC represents the number of symbols designed for AGC, where AGC is usually located at the beginning of the slot and uses one symbol. The number N_Gap represents the number of symbols for guard gap designed for RX / TX switching, and is usually located at the end of the slot. The value of N_PSFCH is explicitly configured per carrier or per BWP, and the number N_PSFCH can be set to zero if all symbols available for sidelink in a slot can be used for PSFCH. AGC for PSFCH is usually located before N_PSFCH symbols. The value of N_PSFCH_AGC can be set to zero if there is no PSFCH resource configured in the slot or all symbols available for sidelink in a slot can be used for PSFCH. The gap for PSFCH is used for RX / TX switching, and thus is usually immediately before PSFCH_AGC symbols. The value of N_PSFCH_Gap can be set to zero if any of the following conditions is met:

[0055] • all symbols available for sidelink in a slot can be used for PSFCH; or

[0056] • there is no PSFCH resource configured before N_Gap symbols; or

[0057] • there is PSFCH resource configured before N_Gap symbols, but the subcarrier spacing (SCS) of the carrier is 15 kHz (in case of 15 kHz, PSFCH_Gap can share symbols with AGC for PSFCH); or,

[0058] • there is PSFCH resource configured before N_Gap symbols, but the terminal device is not allowed to change TX / RX direction in the middle of the slot (in this case, no gap symbol is needed); or,

[0059] • there is PSFCH resource configured before N_Gap symbols, but PSFCH can be transmitted in the first part of N-Gap symbols. In this case, PSFCH_Gap is transmitted in the first part of symbols, the first part of PSFCH_AGC is transmitted in the second part of symbols, and the remaining PSFCH AGC shares symbols with PSFCH. The second half of PSFCH can be transmitted in the first part of N_Gap symbols, and N_Gap only uses the second part of N_Gap symbols.

[0060] As mentioned above, the duration of PSSCH can be different for different SCS of the carrier, and thus the determination of the duration of the sidelink data channel is also based on the subcarrier spacing. As Figure 3 shown, for different SCS, the symbols have different sizes and the gap and ACG also have different durations. For example, for 15 KHz, the gap needs 13 μβ, the ACG needs 35 μβ, and the size of the useful symbol is 66.667, in this case, the gap and ACG for PSFCH can share one symbol, while for other SCS, the gap and ACG need to use more symbols.

[0061] In some embodiments of the disclosure, as an alternative, the number of symbols available for the sidelink data channel on the subchannel(s) containing the sidelink control channel and the subchannel(s) not containing the sidelink control channel can also be determined respectively. This means that the number of symbols available for the sidelink data channel subchannel(s) can be determined by further considering whether the subchannel(s) contain PSCCH.

[0062] Next, referring to Figure 2B another example method for determining the PSSCH duration according to embodiments of the disclosure is described.

[0063] As Figure 2B shown, in a slot with 14 symbols, there is PSSCH_0 on the subchannel containing PSCCH, and PSSCH_1 on the subchannel not containing PSCCH. For the two subchannels, the duration of PSSCH can be determined respectively.

[0064] For Figure 2B the duration of PSSCH_1 as shown, its duration can be determined in a similar manner as Figure 2A shown, i.e.,

[0065] D_PSSCH_1 = D_PSSCH (Equation 2)

[0066] More details can be referred to the description of Figure 2A and thus will not be repeated here.

[0067] For Figure 2B the duration of PSSCH_0 as shown, its duration can be further determined by taking into account PSCCH. For example, the duration of PSSCH_0 (i.e., N_PSSCH_0) can be determined as:

[0068] D_PSSCH_O=N_Symb-N_AGC-N_Gap-N_PSFCH-k_PSFCH_AGC-k_PSFCH_Gap-N_PSCCH (Equation 3)

[0069] in

[0070] N_Symb represents the total number of OFDM symbols for PSSCH in the time slot;

[0071] N_AGC represents the number of symbols in the time slot that are for AGC;

[0072] N_Gap represents the number of symbols in the time slot for the guard gap;

[0073] N_PSFCH represents the number of symbols for PSFCH in the time slot;

[0074] N_PSFCH_AGC represents the number of symbols in the time slot that have AGC for PSFCH;

[0075] N_PSFCH_Gap represents the number of symbols in the time slot corresponding to the PSFCH gap; and

[0076] N_PSCCH represents the number of symbols for PSCCH in the time slot.

[0077] Using the above equations, the terminal device can determine the durations of PSSCH_0 and PSSCH-1 respectively.

[0078] exist Figure 2A and Figure 2B The table shows the specific number of symbols for AGC, GP, PSFCH, PSFCH_AGC, PSFCH_GP, and PSCCH. However, Figure 2A and Figure 2B This is for illustrative purposes only, and this disclosure is not limited thereto. In fact, these specific numbers may vary in different situations or scenarios.

[0079] Refer again Figure 1 In block 130, the receiving terminal device may determine the DMRS pattern to be used for the sidelink data channel based on the number of additional DMRS symbols received in the sidelink data channel and the determined duration of the sidelink data channel.

[0080] In some embodiments of this disclosure, the terminal device determines a DMRS pattern in a predetermined DMRS pattern mapping table corresponding to the number of additional DMRS symbols received by the sidelink data channel and the determined duration of the sidelink data channel. Reference will be made to this table for illustrative purposes only. Figures 4 to 8 To describe the example DMRS pattern mapping table.

[0081] Figure 4 An example DMRS pattern mapping table according to an embodiment of this disclosure is shown. (As...) Figure 4 As shown, Table 1 is obtained by left-shifting the single-symbol DMRS for PUSCH mapping type A (where one symbol is disabled for frequency hopping within a time slot) by one symbol, with the symbols indexed from 0 relative to the time slot start. Due to the left shift, earlier channel estimation can be achieved. The terminal device can obtain the DMRS pattern from Table 1 based on the determined duration of the PSSCH and the number of additional DMRS symbols indicated in the received SCI. For example, for a PSSCH duration of 8 and an additional DMRS symbol number of 2, the DMRS pattern can be determined as (1, 6).

[0082] Figure 5 Another example DMRS pattern mapping table according to an embodiment of this disclosure is shown. (e.g.) Figure 5 As shown, Table 2 is obtained by combining and left-shifting single-symbol DMRS of PUSCH mapping type A (where one symbol of frequency hopping within the time slot is disabled) and single-symbol DMRS of PUSCH mapping type B (where the duration of PSSCH with frequency hopping within the time slot is disabled for 5 to 7 symbols), with the symbols indexed from 0 relative to the time slot start. Due to the left shift, earlier channel estimation can also be achieved, and for durations of 5, 6, and 7, additional DMRS symbols can be used, thus making the channel estimation more accurate. The terminal device can determine the DMRS pattern from Table 2 based on the determined duration of the PSSCH and the number of additional DMRS symbols indicated in the received SCI. For example, for a PSSCH duration of 6 and an additional DMRS symbol count of 2, the DMRS pattern can be determined as (1, 5).

[0083] Figure 6 Another example DMRS pattern mapping table according to an embodiment of this disclosure is shown. (e.g.) Figure 6 As shown in Table 3, it reuses single-symbol DMRS for PUSCH mapping type A (where one symbol is disabled for intra-slot frequency hopping), and the symbols are indexed starting from 0 relative to the slot start. That is, Table 3 and... Figure 3The difference in Table 1 is that the single-symbol DMRS is not shifted left. Therefore, it does not provide the benefit of earlier channel estimation; however, due to the reuse of the PDSCH / PUSCH mapping type ADMRS pattern, interference cancellation between the sidelink and downlink can be facilitated, and interference cancellation is simpler because the terminal device can know the DMRS patterns on both the sidelink data channel and the downlink channel simultaneously and interference cancellation can be performed based on this. The terminal device can determine the DMRS pattern from Table 3 based on the determined duration of the PSSCH and the number of additional DMRS symbols indicated in the received SCI. For example, for a PSSCH duration of 8 and an additional DMRS symbol number of 2, the DMRS pattern can be determined as (2, 7).

[0084] Figure 7 Another example DMRS pattern mapping table according to an embodiment of this disclosure is shown. (As follows) Figure 7 As shown in Table 4, single-symbol DMRS can be reused for PUSCH mapping type B (where intra-slot frequency hopping is disabled), and the symbols are indexed starting from 0 relative to the first PSSCH symbol in (multiple) sub-channels. Due to the reuse of the PUSCH mapping type B DMRS pattern, the solution is much simpler and allows for earlier channel estimation. The terminal device can obtain the DMRS pattern from Table 4 based on the determined duration of the PSSCH and the number of additional DMRS symbols indicated in the received SCI. For example, for a PSSCH duration of 8 and an additional DMRS symbol number of 2, the DMRS pattern is (0, 6).

[0085] Figure 8 Another example DMRS pattern mapping table according to an embodiment of this disclosure is shown. (As follows) Figure 8 As shown, different mapping tables can be used based on the configuration or pre-configuration determined by the duration of PSSCH. For example, if the duration of PSSCH is determined without considering PSCCH, i.e., using... Figure 2A The scheme shown can be used in Table 3. However, for determining the duration of PSSCH considering PSCCH, i.e., using... Figure 2B The schemes shown can be used in Table 4. Therefore, different configurations or pre-configurations of the duration-determining solution can have the benefits of Table 3 or Table 4.

[0086] In some embodiments of this disclosure, the number of additional DMRS symbols for the PSSCH can be indicated in the first phase of a two-stage SCI. That is, receiving sidelink control information (SCI) from the transmitting terminal equipment includes receiving the SCI in the first phase of the two-stage SCI. In some embodiments of this disclosure, the SCI can be received via physical layer signaling; that is, receiving sidelink control information (SCI) includes receiving the SCI via physical layer signaling. This differs from the NR Uu interface and allows for dynamic adjustment of the number of additional DMRS symbols.

[0087] In some embodiments of this disclosure, the SCI indicates the number of additional DMRS symbols to be used in a time slot that is the same as or later than the time slot in which the SCI is received. That is, the SCI indicating the number of additional DMRS symbols for the PSSCH in time slot n is transmitted in time slot m, where m is equal to or less than n. Additionally, in some embodiments of this disclosure, the SCI indicating the number of additional DMRS symbols has at least two bits. For example, two bits can be used to indicate four different numbers, such as... Figures 4 to 8 The numbers 0, 1, 2, and 3 are shown. However, this disclosure is not limited to these; fewer or more bits may be used for SCI.

[0088] Figure 9 Another communication method according to an embodiment of the present disclosure is illustrated. This other communication method can be performed at a transmitting terminal device in sidelink communication.

[0089] like Figure 9 As shown, in step 910, the transmitting terminal device determines the duration of the sidelink data channel based on the number of symbols in the time slot and the number of symbols in the sidelink feedback channel.

[0090] In some embodiments of this disclosure, the transmitting terminal device may also determine the duration of the sidelink data channel based on the subcarrier interval. For example... Figure 3 As shown, the parameter configurations differ for different SCSs of the carrier, and therefore the duration of the PSSCH may differ, and thus the duration of the sidelink data channel can also be determined based on the subcarrier spacing.

[0091] In some embodiments of this disclosure, the transmitting terminal device may determine the duration of the sidelink data channel within a time slot as the duration of the sidelink data channel without considering the sidelink control channel.

[0092] In some embodiments of this disclosure, the transmitting terminal device may determine the number of symbols available for the sidelink data channel on (multiple) sub-channels including the sidelink control channel and the number of symbols available for the sidelink data channel on (multiple) sub-channels not including the sidelink control channel.

[0093] The process of determining the PSSCH duration at the sending terminal device is similar to that at the receiving terminal device. For details regarding the determination of the PSSCH duration, please refer to [reference needed]. Figure 2A and Figure 2B The description is already provided and will not be repeated here.

[0094] In box 920, the transmitting terminal device determines the number of additional DMRS symbols. For example, the terminal device may determine the number of additional DMRS symbols based at least on the relative speeds of the transmitting terminal device and the receiving terminal device.

[0095] The relative speed between the transmitting and receiving devices reflects the rate of change of the sidelink data channel, which is highly dependent on channel quality. Therefore, it can be a crucial factor in determining the number of additional DMRS symbols. In other words, the number of additional DMRS symbols can be positively correlated with the relative speed. Thus, relative speed can be considered when determining the number of additional DMRS symbols. This solution is applicable to both multicast and unicast communications, and the relative speed can be provided from the higher layers of the transmitting terminal device down to the physical layer.

[0096] Alternatively or concurrently, the determination of the number of additional DMRS symbols may be based on any of the following factors:

[0097] • The subcarrier spacing (SCS) to be used in the sidelink data channel;

[0098] • The absolute speed of the transmitting terminal equipment and the receiving terminal equipment;

[0099] • Modulation and coding scheme (MCS).

[0100] Next, in block 930, the transmitting terminal device determines the DMRS pattern to be used for the sidelink data channel based on the number of additional DMRS symbols of the sidelink data channel and the determined duration of the sidelink data channel. In some embodiments of this disclosure, the transmitting terminal device may determine the DMRS pattern corresponding to the number of additional DMRS symbols of the sidelink data channel and the determined duration of the sidelink data channel in a predetermined DMRS pattern mapping table. The predetermined DMRS pattern mapping table may be a reference... Figures 4 to 8 Any of those shown. For details, please refer to the reference. Figures 4 to 8 The description.

[0101] Then, in box 940, the transmitting terminal device sends sidelink control information (SCI) to the receiving terminal device, the SCI indicating the number of additional DMRS symbols for the sidelink data channel.

[0102] In some embodiments of this disclosure, the transmitting terminal device may transmit the SCI in the first stage of a two-stage SCI. In some embodiments of this disclosure, the transmitting terminal device may transmit the SCI via physical layer signaling.

[0103] In some embodiments of this disclosure, the transmitting terminal device may also send an additional number of DMRS symbols to the network device based on whether the sidelink communication is performed in Mode 1. The sidelink communication may be performed in either Mode 1 or Mode 2. In Mode 1, the network device will schedule resources for both terminal devices; while in Mode 2, the transmitting terminal device monitors channel availability and selects resources for the sidelink communication itself. In the case of Mode 1, the transmitting terminal device may also send an additional number of DMRS symbols to the network device to assist the network device in scheduling transmission resources for the sidelink communication.

[0104] In some embodiments of this disclosure, SCI indicates the number of additional DMRS symbols to be used in the same or later time slot compared to the time slot in which the SCI is received.

[0105] In the above text, reference Figure 9 Briefly describe method 900 implemented at the sending terminal device. For details regarding the operation of method 900, please refer to [reference needed]. Figures 1 to 8 The description.

[0106] In addition, methods 100 and 900 are... Figure 1 and Figure 9 The operations are described in the order shown. However, these operations are not necessarily performed strictly in the order shown. For example, the operation in box 110 may be performed after the operation in box 120, and the operations in boxes 110 and 120 may be performed simultaneously. As another example, the operation in box 910 may be performed after the operation in box 920, and the operations in both boxes may be performed simultaneously; once the number of additional DMRSs is determined, the operation in box 920 can be performed, meaning that the operation in box 920 may be performed before or simultaneously with the operations in boxes 910 or 930.

[0107] In another aspect, the apparatus for performing method 100 or method 900 may include components for performing the respective steps of method 100 or method 900. These components may be implemented in any suitable form. For example, the components may be implemented in a circuit or software module.

[0108] In some embodiments of this disclosure, an apparatus for performing a communication method 100 is provided. This apparatus may be included in or performed at a receiving terminal device in sidelink communication, and one of its purposes is to provide improved DMRS transmission for a sidelink data channel. The apparatus may include components for receiving sidelink control information (SCI) from a transmitting terminal device, the SCI indicating the number of additional DMRS symbols for the sidelink data channel; components for determining the duration of the sidelink data channel based on the number of symbols within a time slot and the number of symbols for the sidelink feedback channel; and components for determining a DMRS pattern to be used for the sidelink data channel based on the number of received additional DMRS symbols and the determined duration of the sidelink data channel.

[0109] In some embodiments of this disclosure, the duration of the sidelink data channel can also be determined based on the subcarrier interval.

[0110] In some embodiments of this disclosure, the component for determining the duration of the sidelink data channel within a time slot may also be configured to: determine the maximum number of symbols for the sidelink data channel within the time slot as the duration of the sidelink data channel, without considering the sidelink control channel.

[0111] In some embodiments of this disclosure, the component for determining the duration of the sidelink data channel within a time slot may also be configured to: determine the number of symbols available for the sidelink data channel on the (multiple) sub-channels containing the sidelink control channel and the number of symbols available for the sidelink data channel on the (multiple) sub-channels not containing the sidelink control channel.

[0112] In some embodiments of this disclosure, the component for determining the DMRS pattern to be used for the sidelink data channel may also be configured to: determine, in a predetermined DMRS pattern mapping table, a DMRS pattern corresponding to the number of additional DMRS symbols received by the sidelink data channel and the determined duration of the sidelink data channel.

[0113] In some embodiments of this disclosure, the component for receiving side link control information (SCI) from the transmitting terminal device can be configured to receive SCI in the first phase of a two-stage SCI.

[0114] In some embodiments of this disclosure, the component for receiving side link control information (SCI) can be configured to receive SCI via physical layer signaling.

[0115] In some embodiments of this disclosure, SCI indicates the number of additional DMRS symbols to be used in the same or later time slot compared to the time slot in which the SCI is received.

[0116] In some embodiments of this disclosure, another apparatus for performing the communication method 900 is also provided. This apparatus may be included in or performed at a transmitting terminal device in sidelink communication, one purpose of which is to provide improved DMRS transmission for the sidelink data channel. The apparatus may include components for determining the duration of the sidelink data channel based on the number of symbols in a time slot and the number of symbols for the sidelink feedback channel; components for determining an additional number of DMRS symbols; components for determining a DMRS pattern to be used for the sidelink data channel based on the determined additional number of DMRS symbols and the determined duration of the sidelink data channel; and components for transmitting sidelink control information (SCI) to a receiving terminal device, the SCI indicating the additional number of DMRS symbols for the sidelink data channel.

[0117] In some embodiments of this disclosure, the components for determining the duration of the sidelink data channel may be configured to also determine the duration based on the subcarrier interval.

[0118] In some embodiments of this disclosure, the module for determining the duration of the sidelink data channel within a time slot may also be configured to determine the maximum number of symbols for the sidelink data channel within the time slot as the duration of the sidelink data channel, without considering the sidelink control channel.

[0119] In some embodiments of this disclosure, the component for determining the duration of the sidelink data channel within a time slot may also be configured to determine the number of symbols available for the sidelink data channel on the sub-channel(s) containing the sidelink control channel and the number of symbols available for the sidelink data channel on the sub-channel(s) not containing the sidelink control channel.

[0120] In some embodiments of this disclosure, the component for determining the DMRS pattern to be used for the sidelink data channel may also be configured to determine, in a predetermined DMRS pattern mapping table, a DMRS pattern corresponding to the number of additional DMRS symbols of the sidelink data channel and the determined duration of the sidelink data channel.

[0121] In some embodiments of this disclosure, the component for sending side link control information (SCI) to the receiving terminal device may also be configured to send the SCI in the first phase of a two-stage SCI.

[0122] In some embodiments of this disclosure, the component for sending side link control information (SCI) may also be configured to send SCI via physical layer signaling.

[0123] In some embodiments of this disclosure, SCI indicates the number of additional DMRS symbols to be used in the same or later time slot compared to the time slot in which the SCI is received.

[0124] In some embodiments of this disclosure, the transmitting terminal device may further include components for determining the number of additional DMRS symbols based at least on the relative speeds of the transmitting terminal device and the receiving terminal device.

[0125] In some embodiments of this disclosure, the transmitting terminal device may further include components for determining the number of additional DMRS symbols based at least on the relative speeds of the transmitting terminal device and the receiving terminal device.

[0126] The above briefly describes the apparatus for performing methods 100 and 900. Note that for detailed operation of these apparatuses, please refer to the reference. Figures 1 to 9 A description of the corresponding steps of the method.

[0127] Those skilled in the art will understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this disclosure; many variations, additions, deletions and modifications may readily conceive of from the teachings provided herein, and all such variations, additions, deletions and modifications fall within the scope of this disclosure.

[0128] Additionally, in some embodiments of this disclosure, these devices may include at least one processor. The at least one processor suitable for use with embodiments of this disclosure may include, for example, known or future-developed general-purpose processors and special-purpose processors. These devices may also include at least one memory. The at least one memory may include, for example, semiconductor memory devices such as RAM, ROM, EPROM, EEPROM, and flash memory devices. The at least one memory may be used to store a program of computer-executable instructions. The program may be written in any high-level and / or low-level compilable or interpreted programming language. According to embodiments, the computer-executable instructions may be configured, together with the at least one processor, to cause these devices to at least individually execute, according to reference... Figures 1 to 9 The operational methods discussed.

[0129] Figure 10 A simplified block diagram of a communication system 1000 according to an embodiment of the present disclosure is shown schematically. The communication system 1000 can implement a handover process based on simultaneous connections. The communication system 1000 includes means 1010 that can be implemented as a receiving terminal device or included in a receiving terminal device, and means 1020 that can be implemented as a transmitting terminal device or included in a transmitting terminal device.

[0130] Device 1010 includes at least one processor 1011 (such as a data processor (DP)) and at least one memory (MEM) 1012 coupled to the processor 1011. Device 1010 may also include a transmitter TX and a receiver RX 1013 coupled to the processor 1011, the transmitter TX and receiver RX 1013 being operable for communicatively connecting to device 1020. MEM 1012 stores a program (PROG) 1014. PROG 1014 may include instructions that, when executed on the associated processor 1011, enable device 1010 to operate according to embodiments of the present disclosure, such as method 100. Combinations of at least one processor 1011 and at least one MEM 1012 can form a processing device 1015 suitable for implementing various embodiments of the present disclosure.

[0131] Device 1020 includes at least one processor 1021 (such as a DP) and at least one MEM 1022 coupled to the processor 1021. Device 1020 may also include a suitable TX / RX 1023 coupled to the processor 1021, the TX / RX 1023 being operable for wireless communication with device 1010. MEM 1022 stores PROG 1024. PROG 1024 may include instructions that, when executed on the associated processor 1021, enable device 1020 to operate according to embodiments of the present disclosure, such as method 900. Combinations of at least one processor 1021 and at least one MEM 1022 can form a processing device 1025 suitable for implementing various embodiments of the present disclosure.

[0132] Various embodiments of this disclosure may be implemented by one or more executable computer programs, software, firmware, hardware, or combinations thereof from processors 1011 and 1021.

[0133] MEM 1012 and 1022 can be of any type suitable for the local technical environment and can be implemented using any suitable data storage technology (as non-limiting examples, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory).

[0134] Processors 1011 and 1021 can be of any type suitable for the local technical environment, and by way of non-limiting example, can include one or more of the following: general-purpose computer, special-purpose computer, microprocessor, digital signal processor (DSP), and processor based on a multi-core processor architecture.

[0135] Furthermore, this disclosure may also provide a carrier containing the above-described computer program, wherein the carrier is one of the following: an electronic signal, an optical signal, a radio signal, or a computer-readable storage medium. The computer-readable storage medium may be, for example, an optical disc or an electronic storage device, such as RAM (random access memory), ROM (read-only memory), flash memory, magnetic tape, CD-ROM, DVD, Blu-ray disc, etc.

[0136] The techniques described herein can be implemented in various ways, such that the means for implementing one or more functions of the corresponding apparatus described by the embodiments includes not only prior art modules but also components for implementing one or more functions of the corresponding apparatus described by the embodiments, and may include separate components for each individual function, or components that can be configured to perform two or more functions. For example, these techniques can be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or a combination thereof. For firmware or software, implementation can be performed by modules (e.g., processes, functions, etc.) that perform the functions described herein.

[0137] Exemplary embodiments described herein have been described above with reference to block diagrams and flowcharts of methods and apparatus. It should be understood that each block of the block diagrams and flowcharts, as well as combinations of blocks in the block diagrams and flowcharts, can be implemented in various ways including computer program instructions. These computer program instructions can be loaded onto a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute on the computer or other programmable data processing apparatus, create components for implementing the functions specified in one or more blocks of the flowchart.

[0138] While this specification contains numerous specific implementation details, these should not be construed as limiting the scope of any implementation or the scope of what may be claimed, but rather as descriptions of features that may be specific to a particular implementation. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. Furthermore, while the foregoing features may be described as functioning in certain combinations, or even initially claimed in this way, in some cases one or more features of the claimed combination may be removed from the combination, and the claimed combination may be for sub-combinations or variations thereof.

[0139] It will be apparent to those skilled in the art that the concepts of this disclosure can be implemented in various ways as technology advances. The above embodiments are given for description purposes only and not for limitation, and it should be understood that modifications and variations can be made without departing from the spirit and scope of this disclosure, as will be readily apparent to those skilled in the art. Such modifications and variations are considered to be within the scope of this disclosure and the appended claims. The scope of protection of this disclosure is defined by the appended claims.

Claims

1. A method performed by a terminal device, comprising: determining a number of symbols for transmission of a physical sidelink shared channel, PSSCH, based on a symbol within a slot and a symbol of a physical sidelink feedback channel, PSFCH, and a symbol immediately preceding the symbol of the PSFCH; determining a position of a demodulation reference signal, DMRS, symbol of the PSSCH according to a duration of scheduled resources for the transmission of the PSSCH and the number of DMRS symbols of the PSSCH; and transmitting the PSSCH on the number of symbols within the slot, wherein the number of symbols excludes the symbol of the PSFCH, the symbol immediately preceding the symbol of the PSFCH, and a last symbol of sidelink in the slot, and 2. The method of claim 1, wherein determining the plurality of symbols for transmission of the PSSCH comprises: wherein resource scheduling for the PSSCH starts at a symbol immediately following a first starting symbol in the slot. 3.The method of claim 1, wherein when the duration is 13 symbols, the position of the DMRS symbol of the PSSCH is at symbols 1, 4, 7, and 10. 4.The method of claim 1, wherein the number of DMRS symbols of the PSSCH is indicated by a first-stage sidelink control information, SCI. 5.A method performed by a terminal device, comprising: receiving a sidelink control information, SCI, scheduling transmission of a physical sidelink shared channel, PSSCH; determining a number of symbols for transmission of a physical sidelink shared channel, PSSCH, based on a symbol within a slot and a symbol of a physical sidelink feedback channel, PSFCH, and a symbol immediately preceding the symbol of the PSFCH; and receiving the PSSCH on the number of symbols within the slot, wherein the number of symbols excludes the symbol of the PSFCH, the symbol immediately preceding the symbol of the PSFCH, and a last symbol of sidelink in the slot, and wherein the SCI further comprises a number of demodulation reference signal, DMRS, symbols of the PSSCH, and wherein the method further comprises: determining a position of a DMRS symbol of the PSSCH according to a duration of scheduled resources for the transmission of the PSSCH and the number of DMRS symbols of the PSSCH. 6.The method of claim 5, wherein the SCI is a first-stage SCI. 7.The method of claim 6, wherein when the duration is 13 symbols, the position of the DMRS symbol of the PSSCH is at symbols 1, 4, 7, and 10. 8.A terminal device comprising a processor configured to: determine a number of symbols for transmission of a physical sidelink shared channel, PSSCH, based on a symbol within a slot and a symbol of a physical sidelink feedback channel, PSFCH, and a symbol immediately preceding the symbol of the PSFCH. ​ ​ determine a location of a demodulation reference signal, DMRS, symbol of the PSSCH according to a duration of a scheduled resource for transmission of the PSSCH and a number of DMRS symbols of the PSSCH; and transmit the PSSCH on the plurality of symbols within the slot.

9. The terminal device of claim 8, wherein the processor is configured to determine the plurality of symbols for transmission of the PSSCH by excluding a symbol of the PSFCH in the slot, a symbol immediately preceding the symbol of the PSFCH, and a last symbol of sidelink in the slot, and wherein a resource scheduling for the PSSCH starts at a symbol immediately following a first starting symbol in the slot.

10. The terminal device of claim 8, wherein when the duration is 13 symbols, the location of the DMRS symbol of the PSSCH is at symbols 1, 4, 7, and 10.

11. The terminal device of claim 8, wherein the number of DMRS symbols of the PSSCH is indicated by a first-stage sidelink control information, SCI.

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