Configuring and using device-to-device demodulation reference signals (DMRS)

Abstract

The present application relates to apparatuses and components, systems, and methods including devices for configuring and using demodulation reference signals for device-to-device communication in, for example, new radio.

Description

[0001] Fifth-generation mobile networks (5G) are a wireless standard designed to improve data transmission speed, reliability, availability, and more. While still under development, this standard includes many details related to channels between user devices, such as between base stations and user equipment (UEs), or between UEs themselves. In the latter case, the channel between UEs can be referred to as a sidelink channel. Attached Figure Description

[0002] Figure 1 An example of a network environment according to some implementation schemes is shown.

[0003] Figure 2 An example of a resource grid that can be used for demodulation reference signal (DMRS) transmission according to some implementation schemes is shown.

[0004] Figure 3 An example of a sequence diagram for using DMRS between a transmitter device and a receiver device according to some implementation schemes is shown.

[0005] Figure 4 An example of a resource grid for DMRS transmission using a configuration involving code division multiplexing (CDM) groups associated with more than two antenna ports is shown, according to some implementations.

[0006] Figure 5 An example of a resource grid for DMRS transmission using a configuration involving multiple CDM groups is shown according to some implementation schemes.

[0007] Figure 6 An example of a resource grid for DMRS transmission using a configuration involving power enhancement, according to some implementation schemes, is shown.

[0008] Figure 7 An example of an operational flow / algorithm structure for configuring DMRS transmission using a CDM group associated with more than two antenna ports, according to some implementations, is shown.

[0009] Figure 8 An example of an operational flow / algorithm structure for a device to receive DMRS using a CDM group associated with more than two antenna ports, according to some implementations, is shown.

[0010] Figure 9 An example of a resource grid for DMRS transmission using a configuration involving more than four DMRS locations is shown, according to some implementation schemes.

[0011] Figure 10Another example of a resource grid for DMRS transmission using a configuration involving more than four DMRS locations is shown, according to some implementation schemes.

[0012] Figure 11 An example of an operational flow / algorithm structure for configuring DMRS transmission using more than four DMRS locations is shown, according to some implementation schemes.

[0013] Figure 12 An example of an operational flow / algorithm structure for a device to receive DMRS using more than four DMRS locations, according to some implementations, is shown.

[0014] Figure 13 An example of slot aggregation for DMRS according to some implementation schemes is shown.

[0015] Figure 14 An example of an operational flow / algorithm structure for configuring DMRS transmission using time slot aggregation for device use, according to some implementation schemes, is shown.

[0016] Figure 15 An example of an operational flow / algorithm structure for receiving DMRS using time slot aggregation is shown according to some implementation schemes.

[0017] Figure 16 An example of a receiving component according to some implementation schemes is shown.

[0018] Figure 17 Examples of UEs according to some implementation schemes are shown.

[0019] Figure 18 Examples of base stations according to some implementation schemes are shown. Detailed Implementation

[0020] The following detailed description relates to the accompanying drawings. The same reference numerals may be used in different drawings to identify the same or similar elements. In the following description, specific details, such as particular structures, architectures, interfaces, technologies, etc., are set forth for illustrative and non-limiting purposes to provide a thorough understanding of various aspects of the various embodiments. However, it will be apparent to those skilled in the art that various aspects of the various embodiments may be practiced in other examples departing from these specific details. In some cases, descriptions of well-known devices, circuits, and methods have been omitted so as not to obscure the description of the various embodiments with unnecessary detail. For the purposes of this document, the phrase "A or B" means (A), (B), or (A and B).

[0021] Generally, in device-to-device communication schemes, a first device can communicate with a second device. This type of communication can occur via a sidelink channel, which is called the Physical Sidelink Shared Channel (PSSCH) in 5G cellular networks. A demodulation reference signal (DMRS) can be used to estimate the channel quality of the PSSCH. To improve the flexibility, scalability, and / or associated communication resource usage (e.g., physical resource allocation in the channel, device power consumption, device processing burden) of DMRS transmission / reception, embodiments of this disclosure provide one or more of the following: using a configuration involving code division multiplexing (CDM) groups associated with more than two antenna ports for DMRS transmission / reception; using a configuration involving more than four DMRS locations in a time slot for DMRS transmission / reception; and / or using time slot aggregation for measurements associated with DMRS transmitted / received across multiple time slots.

[0022] The following is a glossary of terms that may be used in this disclosure.

[0023] As used herein, the term "circuit" refers to, is part of, or includes the following: hardware components such as electronic circuits, logic circuits, processors (shared, dedicated, or grouped) or memories (shared, dedicated, or grouped), application-specific integrated circuits (ASICs), field-programmable devices (FPDs) (e.g., field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), complex PLDs (CPLDs), high-capacity PLDs (HCPLDs), structured ASICs, or programmable system-on-chips (SoCs)), digital signal processors (DSPs), etc. In some embodiments, a circuit may execute one or more software or firmware programs to provide at least some of the said functions. The term "circuit" may also refer to a combination of one or more hardware elements and program code for performing the functions (or a combination of circuits used in an electrical or electronic system). In these embodiments, the combination of hardware elements and program code may be referred to as a particular type of circuit.

[0024] As used herein, the term "processor circuit" means, is part of, or includes the following: a circuit capable of sequentially and automatically performing a series of arithmetic or logical operations or recording, storing, or transmitting digital data. The term "processor circuit" may also refer to an application processor, baseband processor, central processing unit (CPU), graphics processing unit, single-core processor, dual-core processor, triple-core processor, quad-core processor, or any other device capable of executing or otherwise operating computer-executable instructions (such as program code, software modules, and / or functional procedures).

[0025] As used herein, the term "interface circuit" refers to, is part of, or includes a circuit that enables the exchange of information between two or more components or devices. The term "interface circuit" can refer to one or more hardware interfaces, such as buses, I / O interfaces, peripheral component interfaces, network interface cards, etc.

[0026] As used herein, the term "user equipment" or "UE" refers to equipment of a remote user that has radio communication capabilities and can describe network resources in a communication network. Furthermore, the term "user equipment" or "UE" can be considered synonymous and can be referred to as a client, device, mobile phone, mobile device, mobile terminal, user terminal, mobile unit, mobile station, mobile user, subscriber, user, remote station, access agent, user agent, receiver, radio equipment, reconfigurable radio equipment, reconfigurable mobile device, etc. Additionally, the term "user equipment" or "UE" can include any type of wireless / wired equipment or any computing device that includes a wireless communication interface.

[0027] As used herein, the term "base station" refers to a device with radio communication capabilities, i.e., a device (or more simply, a network) within a communication network, and can be configured as an access node in that network. The UE's access to the communication network can be managed at least partially by the base station, thereby connecting the UE to the base station to access the communication network. Depending on the Radio Access Technology (RAT), a base station may be referred to as a gNodeB (gNB), eNodeB (eNB), access point, etc.

[0028] As used herein, the term "computer system" means any type of interconnected electronic device, computer device, or component thereof. Additionally, the term "computer system" or "system" may refer to the various components of a computer that are communicatively coupled to each other. Furthermore, the term "computer system" or "system" may refer to multiple computer devices or multiple computing systems that are communicatively coupled to each other and configured to share computing resources or network resources.

[0029] As used herein, the term "resource" refers to physical or virtual devices, physical or virtual components within a computing environment, or physical or virtual components within a specific device, such as computer equipment, mechanical equipment, memory space, processor / CPU time, processor / CPU utilization, processor and accelerator load, hardware time or utilization, power supply, input / output operations, port or network sockets, channel / link allocation, throughput, memory utilization, storage, network, databases and applications, units of workload, etc. "Hardware resource" can refer to computing, storage, or networking resources provided by physical hardware components. "Virtualized resource" can refer to computing, storage, or networking resources provided by virtualization infrastructure to applications, devices, systems, etc. The terms "network resource" or "communication resource" can refer to resources that computer equipment / systems can access via a communication network. The term "system resource" can refer to any kind of shared entity providing services and can include computing or network resources. System resources can be considered as a coherent set of functions, network data objects, or services accessible through a server, wherein such system resources reside on a single host or multiple hosts and are clearly identifiable.

[0030] As used herein, the term "channel" refers to any tangible or intangible transmission medium used for transmitting data or data streams. The term "channel" may be synonymous or equivalent with "communication channel," "data communication channel," "transmission channel," "data transmission channel," "access channel," "data access channel," "link," "data link," "carrier," "radio frequency carrier," or any other similar term indicating a path or medium through which data is transmitted. Additionally, as used herein, the term "link" refers to a connection between two devices used for transmitting and receiving information.

[0031] As used in this article, the terms "instantiate" and "instantiate" refer to the creation of an instance. "Instance" also refers to the concrete occurrence of an object, which may occur, for example, during the execution of program code.

[0032] The term "connection" can mean that two or more elements at a common communication protocol layer have an established signaling relationship with each other through a communication channel, link, interface, or reference point.

[0033] As used herein, the term "network element" refers to physical or virtualized equipment or infrastructure used to provide wired or wireless communication network services. The term "network element" may be considered synonymous with or referred to as networked computers, network hardware, network equipment, network nodes, virtualized network functions, etc.

[0034] The term "information element" refers to a structural element that contains one or more fields. The term "field" refers to the individual content of an information element, or the data element that contains that content. An information element may include one or more additional information elements.

[0035] Figure 1 A network environment 100 according to some implementation schemes is illustrated. Network environment 100 may include UE 104 and gNB 108. gNB 108 may be a base station providing radio access, for example, UE 104 may communicate with gNB 108 through a 3GPP New Radio (NR) cell. UE 104 and gNB 108 may communicate through an air interface compatible with 3GPP technical specifications, such as those defining the fifth-generation (5G) NR system standard.

[0036] The gNB 108 can transmit information (e.g., data and control signaling) in the downlink direction by mapping logical channels to transport channels and transport channels to physical channels. Logical channels can transmit data between the Radio Link Control (RLC) and MAC layers; transport channels can transmit data between the MAC and PHY layers; and physical channels can transmit information across the air interface. Physical channels may include the Physical Broadcast Channel (PBCH), the Physical Downlink Control Channel (PDCCH), and the Physical Downlink Shared Channel (PDSCH).

[0037] The PBCH can be used to broadcast system information that UE 104 can use for initial access to the serving cell. The PBCH can be transmitted together with the Physical Synchronization Signal (PSS) and the Secondary Synchronization Signal (SSS) in the Synchronization Signal (SS) / PBCH block. During the cell search process (including cell selection and reselection) and for beam selection, UE 104 can use the SS / PBCH block (SSB).

[0038] PDSCH can be used to transmit end-user application data, signaling radio bearer (SRB) messages, system information messages (other than MIBs), and paging messages.

[0039] The PDCCH can transmit DCIs used by the gNB 108 scheduler to allocate both uplink and downlink resources. DCIs can also be used to provide uplink power control commands, configure time slot formats, or indicate that preemption has occurred.

[0040] The gNB 108 can also transmit various reference signals to the UE 104. These reference signals may include DMRS for the PBCH, PDCCH, and PDSCH. The UE 104 can compare the received version of the DMRS with a known sequence of transmitted DMRS to estimate the impact of the propagation channel. The UE 104 can then apply phase inversion of the propagation channel during the demodulation process corresponding to the physical channel transmission.

[0041] The reference signal may also include a Channel State Information Reference Signal (CSI-RS). The CSI-RS can be a multi-purpose downlink transmission that can be used for CSI reporting, beam management, connection mode mobility, radio link failure detection, beam failure detection and recovery, and fine-tuning of time and frequency synchronization.

[0042] Reference signals and information from the physical channel can be mapped to resources in the resource grid. For a given antenna port, subcarrier spacing configuration, and transmission direction (e.g., downlink or uplink), there exists a resource grid. The basic unit of the NR downlink resource grid can be a resource element, which can be defined by a subcarrier in the frequency domain and an orthogonal frequency division multiplexing (OFDM) symbol in the time domain. Twelve consecutive subcarriers in the frequency domain can constitute a physical resource block (PRB). A resource element group (REG) can include a PRB in the frequency domain and an OFDM symbol in the time domain, for example, twelve resource elements. A control channel element (CCE) can represent a resource group used for transmitting the PDCCH. One CCE can be mapped to multiple REGs, for example, six REGs.

[0043] UE 104 can use physical uplink channels to transmit data and control information to gNB 108. Different types of physical uplink channels are possible, including, for example, the Physical Uplink Control Channel (PUCCH) and the Physical Uplink Shared Channel (PUSCH). The PUCCH carries control information from UE 104 to gNB 108, such as uplink control information (UCI), while the PUSCH carries data services (e.g., end-user application data) and may also carry UCI.

[0044] UE 104 and gNB 108 can perform beam management operations to identify and maintain desired beams for transmissions in both the uplink and downlink directions. Beam management can be applied to both PDSCH and PDCCH in the downlink direction and PUSCH and PUCCH in the uplink direction.

[0045] In the example, communication with the gNB 108 and / or the base station can utilize channels in the Frequency Range 1 (FR1) band, the Frequency Range 2 (FR2) band, and / or the High Frequency Range (FRH) band. The FR1 band includes both licensed and unlicensed bands. The NR unlicensed band (NR-U) includes spectrum shared with other types of Radio Access Technologies (RATs) (e.g., LTE-LAA, WiFi, etc.). A Listen-Before-Speak (LBT) process can be used to avoid or minimize collisions between different RATs in the NR-U, whereby the device should apply a Clear Channel Assessment (CCA) check before using the channel.

[0046] like Figure 1As further illustrated, network environment 100 may further include another UE 106, and gNB 108 may be connected to gNB 108-UE 104 in a similar manner. UE 104 may also be connected to UE 106 via sidelink channels. These sidelink channels may include PSSCH and Physical Sidelink Control Channel (PSCCH). PSSCH may be similar to PDSCH and may carry data in a one-to-one or one-to-many scheme. In other words, UE 104 may be a transmitter device transmitting data on PSSCH to one or more devices (including UE 106), or a receiver device in a set of devices receiving data from UE 106 on PSSCH. PDSCH may be similar to PDCCH and may carry sidelink control information (SCI). SCI is similar to DCI and includes information about resource allocation on PSSCH.

[0047] To receive data on the PSSCH, a device (e.g., UE 106 receiving data from UE 104) needs to estimate the channel on the PSSCH. DMRS can be transmitted in the PSSCH for channel estimation. The DMRS configuration for the PSSCH is generally more restricted than that for the PDSCH. This configuration is described in the next figure.

[0048] Figure 2 An example of a resource grid that can be used for DMRS transmission according to some implementations is shown. This resource grid, illustrated from the perspective of a transmitter device (e.g., UE 104), is configured as a resource pool for a receiver device (e.g., UE 106), where the resource pool includes resource elements that can be used to carry DMRS. However, this resource grid is equivalently applied to the receiver device.

[0049] Typically, a resource pool is a set of resources defined by subsets of subframes and the resource blocks available within those subframes. Resource blocks repeat in time periods called PSCCH periods. The resource pool reserves physical resources for transmitting sidelink data (including associated control). A resource element (RE) is the minimum physical resource and comprises one subcarrier during one OFDM symbol. A resource block comprises a set of consecutive carriers in the frequency domain (e.g., twelve). In the time domain, a frame comprises multiple subframes, and each subframe comprises multiple time slots. Time slots are formed by multiple symbols, such as OFDM symbols.

[0050] Resource pools can be represented using resource grid 200, which shows time-domain resources on the horizontal axis and frequency-domain resources on the vertical axis. As shown, resource grid 200 illustrates time slots comprising thirteen symbols (numbered "1" to "13" on the horizontal axis) and twelve subcarriers (numbered "0" to "11" on the vertical axis). Each square in the diagram represents a resource element. Each square marked with a diagonal line represents a resource element carrying DMRS.

[0051] For sidelink channels, DMRS Type 1 is typically used with a time-domain pattern of two, three, or four symbols (or time-domain density). Type 1 involves a frequency-domain pattern (or frequency-domain density) where each other resource element in the frequency domain is occupied by DMRS. The time-domain pattern indicates the location (sometimes referred to as position or DMRS position) of the resource element occupied by DMRS in the time domain (e.g., two, three, or four positions in a time slot). The time pattern is selected by the transmitter device based on, for example, the transmitter device and / or receiver device's downlink travel speed or the modulation and coding scheme (MCS) used, and is indicated to the receiver device in the SCI. DMRS is mapped to physical resources using Gold sequences and Orthogonal Cover Codes (OCC). To observe orthogonality and given the time-domain and frequency-domain patterns, the configuration defined for DMRS transmission in the PSSCH is typically mapped to two antenna ports, and the DMRS position has a DMRS length of two symbols (e.g., a first OFDM symbol at a first position equal to the DMRS position, and a second OFDM symbol at a second position adjacent to the first position). Therefore, a single CDM group can be defined, where this CDM group is associated with two antenna ports (e.g., antenna ports). p "1000" and "1001" are associated; this CDM group can be called a dual-port DMRS CDM group, and can support type 1 mode with two, three or four symbol time-domain modes and two symbol lengths.

[0052] The above DMRS configuration (for example, such as) Figure 2 The coverage (shown) applies to device-to-device communication where such devices are located within a vehicle. Coverage is limited to a maximum coupling loss of approximately 140 dB. However, device-to-device communication can cover other use cases where these devices are, for example, mobile devices (e.g., smartphones) and / or their accessories (e.g., smartwatches). In these and other use cases, longer or different distances may be required for communication between the device (e.g., over 100,000 meters) and a non-line-of-sight (NLOS) channel. This requirement can be translated into a maximum coupling loss of approximately 160 dB (e.g., an additional 20 dB).

[0053] In such use cases, the use of Type 1 mode with two, three, or four symbol time-domain modes may not meet the requirements. Therefore, a more flexible, scalable, and / or efficient use of communication resources (e.g., physical resource allocation in the channel, device power consumption, device processing burden, etc.) for DMRS transmission / reception is required. Embodiments of this disclosure provide one or more of the following: a configuration for DMRS transmission / reception involving CDM groups associated with more than two antenna ports; a configuration for DMRS transmission / reception involving more than four DMRS locations in a time slot; and / or time slot aggregation for measurements associated with DMRS transmission / reception across multiple time slots. Figures 4 to 8 The diagram shows the use of more than two antenna ports. Figures 9 to 12 The document shows the use of more than four DMRS locations. And... Figures 13 to 15 The use of time slot aggregation is shown in the figure.

[0054] Figure 3 An example of a sequence diagram 300 for using DMRS between transmitter device 310 and receiver device 320 according to some embodiments is shown. A sidelink channel, such as PSSCH, exists between transmitter device 310 and receiver device 320. Transmitter device 310 can be a UE or a base station. Similarly, receiver device 320 can be a UE or a base station. Transmitter device 310 typically configures physical resources for DMRS transmission to receiver device 320. In contrast, receiver device 320 receives DMRS based on its configuration, performs DMRS measurements, and performs channel estimation of the sidelink channel (e.g., PSSCH) based on the DMRS measurements.

[0055] In the example, sequence diagram 300 includes a transmitter device 310 and a receiver device 320 exchanging capability information. Specifically, the transmitter device 310 can indicate to the receiver device 320 its capabilities regarding phase continuity, such as whether the transmitter device 310 can maintain phase after a change in duplex direction. Similarly, the receiver device 320 can indicate its phase continuity capabilities to the transmitter device 310. Figures 13 to 15 As further described, phase continuity capability can affect how time slot aggregation is used for DMRS transmission / reception. Phase continuity capability can be indicated using higher-layer signaling, such as RRC signaling (e.g., as an information element in an RRC message).

[0056] Next, sequence diagram 300 includes a transmitter device that generates a configuration for DMRS transmission in the sidelink channel and instructs this configuration to receiver device 320. This configuration may involve any or a combination of the following: CDM groups associated with more than two antenna ports; the use of more than four DMRS locations in a time slot; and / or the use of time slot aggregation. In one example, higher-level signaling, such as RRC signaling (e.g., as a set of information elements in one or more RRC messages), is used to indicate the configuration. In another example, different potential configurations are indicated using RRC signaling (e.g., multiple resource pools), and the selection of a particular configuration is indicated using an SCI (e.g., one resource pool is indicated as being selected in the SCI). In yet another example, the SCI can be used to indicate the configuration.

[0057] like Figure 3 As further shown, sequence diagram 300 includes a transmission device 310 that transmits DMRS to a receiving device 320 in a sidelink channel. For example, the DMRS is configured to map physical resources to the sidelink channel, and the DMRS transmission occurs based on this mapping.

[0058] Receiver device 320 receives DMRS based on its configuration, performs various DMRS-related measurements, and estimates the sidelink channel used for demodulation. Additionally, receiver device 320 can send feedback regarding its configuration to transmitter device 310. This feedback allows transmitter device 320 to dynamically change its configuration (e.g., returning to the second step of sequence diagram 300 if a loop is possible). As further described in conjunction with the next figure, different types of information can be included in the feedback, including, for example, channel-related information (e.g., channel quality, path loss, RSRP measurements, etc.) and / or configuration-related information (e.g., a recommendation from receiver device 320 to use another configuration in subsequent DMRS transmissions). Feedback can be sent via, for example, RRC signaling.

[0059] Figure 4 An example of a resource grid 410 for DMRS transmission, configured with CDM groups associated with more than two antenna ports, is shown according to some embodiments. In this example, resource grid 410 supports a multiple-input multiple-output (MIMO) system. For this, orthogonality of the DMRS transmission is required. Orthogonality can be implemented in one or a combination of methods involving: frequency domain mode (e.g., DMRS type 1 or type 2), time domain mode (e.g., the number of DMRS locations), and the OCC used. Figure 4 The diagram shows DMRS type 1 used with four DMRS location modes (although different DMRS location modes are possible, such as (e.g., as...) Figures 8 to 12(In Chinese) Use a positional pattern with two or three positions, or a positional pattern with more than four positions. (Relative to...) Figure 2 The change involves using OCC 420, which allows the CDM group to be associated with more than two antenna ports.

[0060] exist Figure 4 In the example, OCC 420 includes a pattern of four 2x2 resource elements: the first being " "Mode, the second is " "Mode, the third one is " "pattern, and the fourth one is " The four modes can be mapped to four antenna ports (e.g., antenna ports "1000", "1001", "1002", "1003"). These four ports are associated with the same CDM group (e.g., CDM group "0"). Of course, different modes are possible and can be mapped to the same number of antenna ports or different numbers of antenna ports (e.g., eight antenna ports, in which case the CDM group is associated with eight antenna ports).

[0061] Resource grid 410 represents the overlay of four resource grids, each corresponding to a DMRS transmission using one of the four antenna ports. For example, the resource element shown at OFDM symbol "1" and subcarrier "0" indicates a "++++" mode. This corresponds to using... The mode performs DMRS transmissions across four antenna ports (e.g., actual transmissions using four resource elements (one resource element per antenna port)). The CDM group corresponds to the four actual transmission resource elements.

[0062] In resource grid 410, DMRS transmissions according to CDM groups corresponding to four antenna ports are shown, with squares marked diagonally. In the time domain, four DMRS locations with double symbol lengths are used (e.g., at positions "1", "4", "7", and "10"). Orthogonality is provided by using two different OCC modes across other possible subcarriers (e.g., the subcarrier mode depends on the type 1 mode used). Orthogonality is provided by using two other different OCC modes for adjacent resource elements when considering only the time domain.

[0063] Given the Type 1 mode, a second CDM group can also be defined, offset by one subcarrier in the frequency domain relative to the first CDM group. This second CDM group can be defined using the same OCC 420, such that it is mapped to four other antenna ports (e.g., antenna ports “1004”, “1005”, “1006”, and “1008”). In resource grid 410, DMRS transmissions according to the second CDM group corresponding to these four antenna ports are shown, with squares marked by vertical lines.

[0064] The same "++++" mode is indicated by comparing the resource elements at OFDM symbol "1" and subcarrier "0" with the resource elements at OFDM symbol "1" (e.g., the same time-domain location) and subcarrier "1" (e.g., subcarrier offset one). Since it is a type 1 mode, the same OCC mode can be used.

[0065] Thus, one or more CDM groups can be configured, each CDM group being associated with four antenna ports (or a different number of antenna ports than two). This configuration for DMRS transmission in sidelink channels (e.g., PSSCH) is summarized in Table 1 below.

[0066]

[0067] Figure 5 An example of a resource grid 500 for DMRS transmission using a configuration involving multiple CDM groups, according to some embodiments, is shown. As described above, CDM groups can be configured for receiver devices and can be associated with more than four antenna ports. Further, multiple such CDM groups can be configured by the transmitter device for the same receiver device or multiple receiver devices (e.g., a first CDM group using even-numbered subcarriers is configured for a first receiver device, and a second CDM group using odd-numbered subcarriers is configured for a second receiver device). Thus, the transmitter device can indicate to the receiver device, for example, the CDM groups (or the antenna ports of these CDM groups) configured for that device using an SCI. Some of these configured CDM groups can be used for DMRS transmission to the receiver device, while the remaining configured CDM groups may not be used (e.g., in this case, the transmitter device can flexibly use these remaining CDM groups for DMRS transmission to another device). In this case, the transmitter device can also indicate to the receiver device, for example, whether a configured CDM group is used, using an SCI. However, regardless of whether the configured CDM group is used, the receiver UE can perform rate matching (e.g., PSSCH rate matching) on ​​all configured CDM groups for data on the sidelink channel.

[0068] exist Figure 5 In the diagram, two CDM groups are configured for the receiver device in the SCI. The first CDM group (or a group of such groups) is indicated by rectangles marked with diagonal lines. The second CDM group (or a group of such groups) is indicated by rectangles marked with vertical lines. As indicated by the label “DMRS” in each rectangle, the first CDM group is used for DMRS transmission to the receiver device and may contain scheduled DMRS ports to the receiver device (e.g., antenna ports “1000” through “1003”). In contrast, and as indicated by the label “Emp.” (short for “empty”) in each rectangle, the second CDM group does not contain DMRS transmissions (e.g., PSSCH resource elements carrying DMRS) or scheduled DMRS ports (e.g., indications that antenna ports “1004” through “1007” are scheduled for DMRS transmission). The remaining resource elements (shown using blank rectangles) carry sidelink channel data (e.g., PSSCH data).

[0069] Here, the SCI indicates that the first and second CDM groups are configured for the receiver device. The SCI may also, but does not necessarily, indicate that the second CDM group is not actually used (or equivalently, only the first CDM group is used). In both cases, the receiver device performs PSSCH rate matching for all CDM groups configured as indicated in the SCI. For example, the receiver device may determine that the resource element at subcarrier "1" and OFDM symbol "0" corresponds to the second CDM group (in... Figure 5 The text is displayed as "empty" because it does not carry DMRS, and decoding of the PSSCH data that was originally carried in the resource element can be disregarded.

[0070] Figure 6 An example of a resource grid 600 for DMRS transmission using a configuration involving power enhancement, according to some embodiments, is shown. As described above, CDM groups can be configured for receiver devices and can be associated with more than four antenna ports. Further, multiple such CDM groups can be configured by transmitter devices, and receiver devices can perform sidelink data rate matching (e.g., PSSCH rate matching) around resource elements in the CDM groups (regardless of whether they are actually used for DMRS transmission). When a second CDM group is configured for a receiver device but not for actual DMRS transmission (e.g.) Figure 5 As shown (indicated by the rectangle marked with a vertical line), the power spectral density (PSD) of the actual DMRS transmission can be increased using a first CDM group also configured for the receiver equipment. This increase includes improvements through scaling factors (…). P(For example, a multiplier greater than one) Increase PSD to improve DMRS coverage. For example, power increase scaling factor ( P ) equals the total number of configured CDM groups ( N configured Divide by the total number of CDM groups used for actual DMRS transmission to the receiver device ( N used )(For example, ).

[0071] Similar to Figure 5 The illustration is in Figure 6 In the diagram, two CDM groups are configured for the receiver device in the SCI. The first CDM group (or a group of such groups) is indicated by a rectangle marked with a diagonal line. The second CDM group (or a group of such groups) is indicated by a rectangle marked with a vertical line. The first group is used for DMRS transmission to the receiver device. However, the second group is not used for DMRS transmission (e.g., in...). Figure 5 In the text, this is correspondingly shown as an "empty" label. Using the scaling factor formula above, the power enhancement scaling factor is two. Thus, the PSD of the DMRS transmission using the first CDM group is enhanced by two (in...). Figure 6 China and Israel P=2 (As shown). By using the second CDM group, no DMRS transmission occurs (e.g., the non-use power scaling factor is increased). P=0 "Indicates that no power is being used for this second CDM group." In contrast, sidelink data transmissions (e.g., using PSSCH resource elements) are not boosted (e.g., by a power scaling factor). P=1 (As instructed).

[0072] Therefore, and as in combination Figures 4 to 6 As described, improvements to DMRS transmission can be achieved by using CDM groups associated with more than two antenna ports. Additional improvements can also be made by configuring more than one CDM group and using PSSCH rate matching as needed based on the configuration, and by applying power enhancements based on the actual usage of each CDM group. Further improvements can also be made by changing the DMRS length and / or by using feedback information to modify the configuration.

[0073] In the example, DMRS length represents the number of DMRS symbols used at each DMRS location, such as the length of one or two DMRS symbols. Compared to single-symbol DMRS, dual-symbol DMRS (or more generally, multi-symbol DMRS) allows for the use of more orthogonal ports among multiple co-scheduled receiver devices and can allow for higher DMRS density (which can improve receiver performance at low signal-to-interference-plus-noise ratio (SINR)). However, in certain situations (e.g., high SINR or good channel conditions), using multi-symbol DMRS is not necessary and may not improve receiver device performance. In such cases, using single-symbol DMRS can improve overall data throughput because additional OFDM symbols can be used for data transmission.

[0074] Thus, the DMRS length can be dynamically changed by switching between single-symbol DMRS and multi-symbol DMRS. In one example, the receiver device is initially configured to use (or by default) multi-symbol DMRS (e.g., dual-symbol DMRS). Configuration can be sent using Master System Information (MIB) signaling, System Information Block (SIB) signaling, or RRC signaling. SCI can also be used to indicate whether to use single-symbol DMRS or multi-symbol DMRS.

[0075] Furthermore, feedback information can be used to switch between single-symbol DMRS or multi-symbol DMRS in the SCI transmitted to the receiver device after the transmitter device receives the feedback information (e.g., to indicate the relevant DMRS length). The feedback information may include channel-related information. In this case, the transmitter device selects the relevant DMRS length and indicates this selection to the receiver device. Additionally or alternatively, the feedback information may include DMRS enhancement information. In this case, the receiver device may indicate a preferred or recommended modification to the configuration used for DMRS transmission, and the transmitter device may indicate the actual modification to the receiver device in the SCI. Alternatively, the receiver device may indicate a modification to the configuration, assuming that the transmitter device will implement the modification, and thus the transmitter device may implement the modification and indicate to the receiver device in the SCI that the modification is complete.

[0076] In the example, channel-related feedback information can include any type of information indicating the quality of a sidelink channel (e.g., PSSCH). For example, channel-related feedback information indicates the distance between the receiver and transmitter devices. Generally, the greater the distance, the worse the quality becomes (and therefore, the greater the likelihood of switching to multi-symbol DMRS). In another illustration, an RSRP measurement or path loss estimate between the receiver and transmitter devices is indicated. Here, a smaller RSRP measurement or a larger path loss estimate indicates a greater likelihood of switching to multi-symbol DMRS. Similarly, a Doppler shift / spread (e.g., velocity) estimate between the receiver and transmitter devices is indicated. And here, a larger estimate indicates a greater likelihood of switching to multi-symbol DMRS.

[0077] DMRS enhancement feedback information can indicate changes to the configuration. This change can be in the time domain and / or the frequency domain. For example, DMRS enhancement feedback information can indicate the DMRS length (e.g., one or two symbols) and / or the number of DMRS positions (e.g., one DMRS position in a time slot for one or two DMRS symbols, two DMRS positions in a time slot each for one or two DMRS symbols, three DMRS positions in a time slot each for one or two DMRS symbols, or four DMRS positions in a time slot each for one or two DMRS symbols). Furthermore, it can indicate the need for PSD enhancement and / or a recommended power enhancement scaling factor.

[0078] Figure 7 Examples of operational flow / algorithm structures 700 for configuring DMRS transmission using CDM groups associated with more than two antenna ports, according to some embodiments, are shown. Transmitter devices may implement operational flow / algorithm structures 700, such as UE 104 or 106, transmitter device 310, or UE 1700 or components thereof, such as processor 1704.

[0079] The operation flow / algorithm structure 700 may include, at 702, generating a configuration for the DMRS for the PSSCH for the receiver device, which indicates a CDM group associated with multiple antenna ports, including more than two antenna ports. For example, the transmitter device may configure a CDM group for the receiver device, wherein the CDM group is associated with four or eight antenna ports. This association is based on the use of OCC, such as... Figure 4The transmitter device can configure more than one CDM group for the receiver device and indicate whether one or more of these CDM groups are in use. The transmitter device can also limit the PSD power enhancement factor based on the use of CDM groups. Furthermore, the DMRS length, DMRS location, and / or PSD power enhancement usage can be limited in the configuration based on feedback information from the receiver device. Thus, the configuration can indicate: for the PSSCH with the receiver device, and in addition to using type 1, whether more than two antenna ports of CDM groups are used, whether more than one CDM group is used, the DMRS length, the DMRS location, and / or the PSD power enhancement usage. In the example, multiple configurations are generated for the receiver device, each of which corresponds to a different resource pool for DMRS transmission in the PSSCH.

[0080] The operation flow / algorithm structure 700 may include: at 704, sending a configuration to the receiver device. For example, the configuration may be signaled via an RRC message. Further, specific parameters of the configuration or changes to the configuration may be signaled via additional RRC messages and / or SCI messages. In the example, when multiple resource pools are configured, RRC or SCI signaling can be used to indicate resource pool selection (or equivalent, configuration selection) to the receiver UE. This selection may be based on feedback information from the receiver device.

[0081] The operation flow / algorithm structure 700 may include: at 706, sending DMRS to the receiver device based on configuration. For example, the DMRS to be sent is mapped to physical resources of the PSSCH according to the configuration, and these physical resources carry the information included in the DMRS.

[0082] Figure 8 An example of an operational flow / algorithm structure 800 for a device to receive DMRS using a CDM group associated with more than two antenna ports, according to some embodiments, is shown. The receiver device may implement the operational flow / algorithm structure 800, such as UE 104 or 106, receiver device 320, or UE 1700 or its components, such as processor 1704.

[0083] The operation flow / algorithm structure 800 may include: at 802, determining a DMRS configuration for the PSSCH, which indicates a CDM group associated with multiple antenna ports, including more than two antenna ports. For example, this configuration is generated by the transmitter device and may indicate: for the PSSCH with the receiver device, and in addition to using type 1, whether more than two antenna ports of CDM groups are used, whether more than one CDM group is used, the DMRS length, the DMRS location, and / or the use of PSD power enhancement. In the example, multiple configurations are generated by the transmitter device for the receiver device, each of the multiple configurations corresponding to a different resource pool for DMRS transmission in the PSSCH. The configuration may be determined based on signaling from the transmitter device. The signaling may use RRC messages. Further, specific parameters of the configuration or changes to the configuration may be signaled via additional RRC messages and / or SCI. In the example, when multiple resource pools are configured, RRC or SCI signaling may be used to indicate resource pool selection (or equivalent, configuration selection) to the receiver UE.

[0084] The operation flow / algorithm structure 800 may include: at 804, receiving the DMRS on the PSSCH based on a configuration using multiple antenna ports, and receiving the DMRS in a resource element (RE) corresponding to the CDM group. In the example, the receiver device is configured to use antenna ports based on a determined configuration.

[0085] The operation flow / algorithm structure 800 may include, at 806, performing channel estimation for the demodulated PSSCH based on the DMRS. For example, the receiver device determines the RE carrying the DMRS to subsequently detect the DMRS and performs relevant measurements for the channel estimation (e.g., subsequently averaged RSRP measurements). If the configured PSD power is increased, these measurements take into account a scaling factor. Further, when decoding the PSSCH data, the UE may perform PSSCH rate matching.

[0086] Figure 9 An example of a resource grid 900 for DMRS transmission using a configuration involving more than four DMRS locations is shown, according to some embodiments. The use of more than four DMRS locations can be achieved either in combination with or independently of CDM groups as previously described above, associated with more than two antenna ports, and can be combined with or independently of... Figures 13 to 15This is achieved through time slot aggregation, as further described below. Generally, higher DMRS density is achieved by using more than four DMRS locations, which can further enhance DMRS transmission / reception for low SINR operation. In particular, low SINR operation can be achieved (by spending a higher proportion of energy on DMRS transmission relative to actual data transmission (e.g., PSSCH data)) and better channel estimation for demodulation, which can improve the reception of actual data.

[0087] Such as combination Figure 2 As described, DMRS density is typically limited to a maximum of four DMRS locations in a time slot. Embodiments of this disclosure relax this limitation by allowing for more than four DMRS locations and higher densities up to all OFDM symbols in a time slot. Furthermore, higher DMRS density can be used in conjunction with PSD enhancement. In the time domain, if a DMRS symbol occupies the same location as a data symbol, a power enhancement scaling factor of one is used (e.g., the DMRS PSD is the same as the data PSD). However, if the location is not occupied by a data symbol, the PSD of the DMRS symbol is enhanced by a scaling factor greater than one. Here, the scaling factor depends on the number of OFDM symbols not used at that location (e.g., the number of OFDM symbols not carrying DMRS or data). For example, if at that location there are six DMRS symbols (each corresponding to one of six even-numbered subcarriers) and six “empty” OFDM symbols (e.g., not transmitted or having zero PSD, and each corresponding to one of six odd-numbered subcarriers), the power enhancement scaling factor is set to two.

[0088] exist Figure 9 In the illustration, the DMRS density increases, causing DMRS symbols to occupy different OFDM symbols in the time slot. This DMRS density is indicated by rectangles marked with diagonal lines. Further, the DMRS symbols correspond to a first CDM group configured for the receiver equipment. This CDM group may, but does not necessarily, use more than two antenna ports. A second CDM group may have been configured for the receiver equipment but is not used (as indicated by rectangles marked with vertical lines). Resource elements corresponding to the second CDM group do not carry DMRS or data (and are indicated as "empty"). The remaining resource elements carry data and are indicated by blank rectangles labeled "data".

[0089] In this diagram, at symbol position "1", there are six DMRS symbols (labeled "DMRS") and six unused OFDM symbols (labeled "Empty"). Therefore, the PSD of each of these six DMRS symbols can be improved by a scaling factor of two. In contrast, at symbol position "3", there are six DMRS symbols and six data symbols (labeled "Data"). Therefore, the PSD of each of these six DMRS symbols is the same as the PSD of each of the six data symbols.

[0090] In the example, transmitter density can indicate the sidelink DMRS configuration to the receiver device, where the configuration includes DMRS density and can be indicated via RRC or SCI signaling. The transmitter device can also indicate the use of PSD boost and / or the power boost scaling factor in the configuration. The configuration can also change dynamically over time, and the receiver device can be notified only of the changes or the entire updated configuration.

[0091] Figure 10 Another example of a resource grid 1000 for DMRS transmission using a configuration involving more than four DMRS locations, according to some implementations, is shown. As shown, there are no unused resource elements. Instead, each resource element carries either DMRS or data. In this case, no power boost is used (e.g., the power boost scaling factor is set to one).

[0092] exist Figure 10 In the illustration, the DMRS density increases, causing DMRS symbols to occupy different OFDM symbols in a time slot. This DMRS density is indicated by rectangles marked with diagonals. Further, the DMRS symbols correspond to a first CDM group configured for the receiver equipment. This CDM group may, but does not necessarily, use more than two antenna ports. A second CDM group is not configured for the receiver equipment, or if a second CDM group is configured, it is reconfigured for data transmission purposes. Therefore, resource elements that do not carry DMRS carry data. These resource elements are indicated by blank rectangles labeled "data".

[0093] In this diagram, at symbol position "1", there are six DMRS symbols (labeled "DMRS") and six data symbols (labeled "Data"). Therefore, the PSD used to transmit the six DMRS symbols is the same as the PSD used to transmit the six data symbols.

[0094] Therefore, and as in combination Figures 9 to 10As described, improvements to DMRS transmission can be achieved by using more than four DMRS locations. Additional improvements can also be achieved by configuring more than one configuration, each corresponding to a different resource pool and applicable based on coverage area. Feedback information can be generated by the receiver device and used by the transmitter and / or receiver devices to select the most relevant resource pool and determine the corresponding configuration.

[0095] In the example, multiple resource pools can be configured, such as up to sixteen. A first resource pool (or equivalent, a first group of multiple resource pools) can be configured and used to communicate with receiver devices in good coverage areas (e.g., when close to the transmitter device, when channel quality is relatively good, etc.). Conversely, a second resource pool (or equivalent, a second group of multiple resource pools) can be configured and used to communicate with receiver devices in poor coverage areas (e.g., when far from the transmitter device, when channel quality is relatively poor, etc.). Generally, the better the device coverage, the lower the DMRS density. Other configuration parameters can also be changed. For example, better device coverage results in shorter DMRS lengths, a lower likelihood of using PSD power enhancement, and fewer CDM groups configured. Thus, different sidelink DMRS configurations can be defined, each corresponding to a different resource pool. Each sidelink DMRS configuration may differ from the remaining sidelink DMRS configurations based on the following: whether the DMRS is configured and transmitted in a denser time-domain mode, the number of DMRS symbols at each DMRS time-domain location (e.g., DMRS length), whether DMRS power density is allowed (e.g., how the PSD scaling factor changes), and the number of CDM groups and the corresponding DMRS type for the OCC mode.

[0096] Thus, the DMRS configuration can be dynamically changed by altering the selection of resource pools. In one example, different configurations of possible resource pools are indicated to the receiver device using RRC signaling. Subsequently, a specific resource selection can be indicated to the receiver device via RRC or SCI signaling. Alternatively, different configurations of possible resource pools are indicated to the receiver device using RRC signaling, and one of these different configurations is indicated as the default or fallback configuration. Subsequently, a specific resource selection can be indicated to the receiver device via RRC or SCI signaling, or the receiver device can fall back to using the default configuration.

[0097] Feedback information can be sent from the receiver device to the transmitter device to select one of the possible configurations. The feedback information may include channel-related information. In this case, the transmitter device selects the relevant configuration and indicates the selection to the receiver device. Additionally or alternatively, the feedback information may include DMRS enhancement information. In this case, the receiver device may indicate a preferred or recommended selection of one of the possible configurations, and the transmitter device may indicate the actual selection to the receiver device in the SCI. Alternatively, the receiver device may indicate the selection and assume that the transmitter device will perform a relevant modification, and further, the transmitter device may perform the modification and indicate to the receiver device in the SCI that the modification is complete.

[0098] In the example, channel-related feedback information can include any type of information indicating the quality of a sidelink channel (e.g., PSSCH). For example, channel-related feedback information indicates the distance between the receiver and transmitter devices. In another illustration, RSRP measurements or path loss estimates between the receiver and transmitter devices are indicated.

[0099] Regarding the fallback sidelink DMRS configuration, the receiver device can use this configuration to subsequently monitor DMRS transmissions based on one or more triggering events. A triggering event could be a periodic time interval (e.g., the receiver periodically uses this configuration for monitoring). Another triggering event could be a loss of communication with the transmitter device or a failure of DMRS detection using the currently selected sidelink DMRS configuration. Yet another triggering event could be an RSRP measurement or path loss estimate, with values ​​within a range or less than / greater than a predefined threshold.

[0100] Figure 11 Examples of operational flow / algorithm structures 1100 for configuring DMRS transmission using more than four DMRS locations are shown according to some embodiments. Transmitter devices may implement operational flow / algorithm structures 1100, such as UE 104 or 106, transmitter device 310, or UE 1700 or components thereof, such as processor 1704.

[0101] Operational flow / algorithm structure 1100 may include: at 1102, generating a DMRS configuration for the receiver device for the PSSCH, the configuration indicating multiple DMRS positions in the time slot, including more than four positions. In the example, each DMRS position corresponds to a symbol position in the time slot and is indicated by the index of that symbol position. The number of DMRS positions (or also referred to as DMRS locations) is at least five and up to the total number of symbol positions in the time slot. DMRS positions may correspond to CDM groups, where a group may, but does not necessarily, be associated with more than two antenna ports. The transmitter device may also configure more than one CDM group for the receiver device, and if so, it may indicate whether the resource elements corresponding to the additional CDM groups are to be used for DMRS transmission or remain empty. Furthermore, the transmitter device may configure resource elements for transmitting data in the PSSCH. PSD power boosting may be used based on the number of CDM symbols and the overlap position with data symbols in the time domain. This configuration may include an indication of PSD power boosting and / or a power boosting scaling factor. In the example, multiple configurations are generated for the receiver device, each of which corresponds to a different resource pool for DMRS transmission in PSSCH.

[0102] The operation flow / algorithm structure 1100 may include: at 1104, sending a configuration to the receiver device. For example, the configuration may be signaled via an RRC message. Further, specific parameters of the configuration or changes to the configuration may be signaled via additional RRC messages and / or SCI messages. In the example, when multiple resource pools are configured, RRC or SCI signaling can be used to indicate resource pool selection (or equivalent, configuration selection) to the receiver UE. This selection may be based on feedback information from the receiver device.

[0103] The operation flow / algorithm structure 1100 may include: at 1106, sending DMRS to the receiver device based on configuration. For example, the DMRS to be sent is mapped to physical resources of the PSSCH according to the configuration, and these physical resources carry the information included in the DMRS.

[0104] Figure 12 An example of an operational flow / algorithm structure 1200 for a device to receive DMRS using more than four DMRS locations, according to some embodiments, is shown. The receiver device may implement the operational flow / algorithm structure 1200, such as UE 104 or 106, receiver device 320, or UE 1700 or its components, such as processor 1704.

[0105] The operation flow / algorithm structure 1200 may include: at 1202, determining a DMRS configuration for the PSSCH, which indicates multiple DMRS positions in the time slot, including more than four positions. In the example, each DMRS position corresponds to a symbol position in the time slot and is indicated by an index of that symbol position. The number of DMRS positions (or also referred to as DMRS locations) is at least five and up to the total number of symbol positions in the time slot. DMRS positions may correspond to CDM groups, where a group may, but does not necessarily, be associated with more than two antenna ports. The transmitter device may also configure more than one CDM group for the receiver device, and if so, it may indicate whether the resource elements corresponding to the additional CDM groups are to be used for DMRS transmission or remain empty. Furthermore, the transmitter device may configure resource elements for transmitting data in the PSSCH. PSD power boosting may be used based on the number of CDM symbols and the overlap position with data symbols in the time domain. This configuration may include an indication of PSD power boosting and / or a power boosting scaling factor. In the example, multiple configurations are generated for the receiver device, each corresponding to a different resource pool for DMRS transmission in the PSSCH. The configuration can be determined based on signaling from the transmitter device. Signaling can use RRC messages. Further, specific parameters of the configuration or changes to the configuration can be signaled via additional RRC messages and / or SCI. In the example, when multiple resource pools are configured, RRC or SCI signaling can be used to indicate resource pool selection (or equivalent, configuration selection) to the receiver UE. Alternatively, instead of using signaling from the transmitter device to indicate configuration selection, the receiver device can automatically select one of the possible configurations based on feedback information, or it can fall back to using the default configuration based on one or more triggering events.

[0106] The operation flow / algorithm structure 1200 may include: at 1204, receiving DMRS on the PSSCH based on configuration, and receiving the DMRS at multiple DMRS locations. In the example, the receiver device is configured to monitor and detect DMRS according to configuration.

[0107] The operation flow / algorithm structure 1200 may include: at 1206, performing channel estimation for the demodulated PSSCH based on the DMRS. For example, the receiver device determines the RE carrying the DMRS to subsequently detect the DMRS and performs relevant measurements for the channel estimation (e.g., subsequently averaged RSRP measurements). If the PSD power is configured to be increased, these measurements take into account a scaling factor. Further, when decoding the PSSCH data, the UE may perform PSSCH rate matching.

[0108] Figure 13An example of time slot aggregation 1300 for DMRS according to some implementations is shown. The use of time slot aggregation 1300 can be implemented in conjunction with or independently of using CDM groups associated with more than two antenna ports and / or using denser DRMS ​​locations, as previously described above. In the example, time slot aggregation 1300 is PSSCH time slot aggregation (repetition). Generally, when PSSCH time slot aggregation is configured, DMRS time-domain bundling can be configured to improve the channel estimation quality of the receiver equipment. Specifically, this is when the PSSCH time slot aggregation configuration indicates that the DMRS transmission scheme does not change (or changes substantially to have a meaningful impact on channel quality estimation) from one time slot to another (e.g., adjacent time slots). In this case, DMRS time-domain bundling can represent the use of DMRS across the aggregated time slots to perform channel estimation (rather than performing that channel estimation for each time slot using only the DMRS received in the time slot).

[0109] In the example, a certain number of ( N slotaggregated The number of time slots is specified and indicated in the receiver device configuration (e.g., via RRC signaling). In this example, the DMRS time domain bundle size is defined based on the number of time slots (e.g., the DMRS time domain bundle size is a number of slots). N slotforbundledDMRS Generally speaking, N slotforbundledDMRS Less than or equal to N slotaggregated .For example, N slotaggregated For four, and N slotforbundledDMRS Two. In this diagram, two DMRS bundles are defined. Specifically, for those from " k Index to k+3 The four time slots of "" are defined, with the first DMRS bundle corresponding to time slot "". k "and time slots" k+1 "And the second DMRS bundle corresponds to the time slot." k+2 "and time slots" k+3 Of course, these quantities are provided for illustrative purposes, and other quantities may exist (e.g., N slotaggregated It is possible to have 256 bundles, and bundle sizes of 64 (producing four DMRS bundles), 128 (producing two DMRS bundles), or 256 (producing one DMRS bundle).

[0110] In the example, time slot aggregation is 1300 (e.g., N slotaggregatedThe bundle size to be used can be indicated to the receiver device via RRC signaling and / or SCI signaling. The bundle size to be used can be indicated in the same signaling or another signaling (e.g., N slotforbundledDMRS ).

[0111] exist Figure 13 In the diagram, slot aggregation 1300 is configured for " k+2 "10 time slots (these time slots are indexed starting from zero)" k (Indexing). Each time slot includes multiple DMRS symbols (indicated by rectangles marked with diagonals and labeled "DMRS") and multiple data symbols (indicated by blank rectangles labeled "Data"). The first time slot (e.g., time slot "0") also includes Automatic Gain Control (AGC) symbols (indicated by rectangles marked with vertical and horizontal lines and labeled "AGC"). Bundle size is also configured. i (For simplicity, " i "exist Figure 13 (This is shown as equal to two, but it can also be a different value). Therefore, in time slots "0" and "1", the DRMS ​​symbols received in these time slots are used for the first channel estimation. In time slot " k "and time slots" k+1 In this context, the DRMS ​​symbols received in these time slots are used for the second channel estimation independently of the first channel estimation.

[0112] The aforementioned DMRS bundling across multiple aggregated time slots is possible because the receiver device can assume that the DMRSs within the same time-domain bundle are quasi-co-located (QCL'ed). In other words, this assumes that these DMRSs share the same channel statistics regarding delay spread, Doppler spread, Doppler shift, average gain, average delay, and / or spatial reception parameters. Therefore, the receiver device can average and / or filter channels within the same bundle based on these channel statistics. Across different time-domain bundles, the receiver device cannot assume that the DMRSs are QCL'ed. Therefore, averaging and filtering are not possible.

[0113] In the example, when a duplex direction change occurs at either device for PSSCH, the transmitter and / or receiver devices may be unable to maintain phase continuity. Specifically, in one duplex direction, the first device can operate as a transmitter device and the second device can operate as a receiver device. This setup is sustained for a first time period (e.g., a first number of time slots). N1). Under certain circumstances, a change in duplex direction occurs, allowing the second device to transmit to the first device. In this case, the second device can operate as a transmitter device and the first device can operate as a receiver device. This setup can last for a second time period (e.g., a second number of time slots). N 2). Subsequently, another duplex direction is generated, allowing the first and second devices to operate again as a transmitter and receiver, respectively. This setup can be sustained for a third time period (e.g., a third number of time slots). N 3).

[0114] When the first duplex direction changes, the first device may be unable to maintain phase (e.g., its phase-locked mechanism does not allow the estimated phase to be locked to before the duplex change). Similarly, when the second duplex direction changes, the first device may also be unable to maintain phase (e.g., its phase-locked mechanism does not allow the estimated phase to be locked to before the duplex change). Additionally or alternatively, the second device may also lack phase-locked mechanism capability.

[0115] In the example, when there is a lack of phase-locked loop (PLL) capability, the time bundle size can be divided into smaller sizes, referred to as dividing the nominal time-domain bundle into multiple actual time-domain bundles. This allocation occurs when the transmitter device cannot support phase continuity (regardless of the receiver device's PLL capability) or when the receiver device cannot support phase continuity (even if the transmitter device can support phase continuity). No allocation occurs when both the transmitter and receiver devices can support phase continuity.

[0116] Therefore, capability information can be exchanged between the two devices, with each device indicating its phase-locked mechanism (PLM) capability to the other. If both devices can support phase continuity, slot aggregation 1300 and bundle size can be used as configured via RRC signaling and / or SCI signaling. Otherwise, allocation occurs and the receiver device can use a smaller bundle segment. For illustration and with reference to the three time periods described above, assume that the three time periods correspond to 256 time slots. First time period N 1. There are exactly 128 time slots, and the second time slot... N 2 and the third time period N 3. These are exactly eighty time slots and forty-eight time slots, respectively. It is also assumed that the time slot aggregation of two hundred and fifty-slots is equal to the bundle size of two hundred and fifty-slots. In this description, three bundle segments are used. The first bundle segment corresponds to the first time period. N 1. And its length is one hundred and twenty-eight time slots. The second and third bundled segments correspond to the second time period. N 2 and the third time period N3. The lengths are eighty and forty-eight time slots, respectively. Therefore, instead of performing channel estimation using DMRS received at different locations within the two hundred and fifty-six time slots, three different channel estimations are performed. The first channel estimation is performed using DMRS received before the first duplex direction change (e.g., at different locations within the first one hundred and twenty-eight time slots). The second channel estimation is performed using DMRS received between the first and second duplex direction changes (e.g., at different locations within the subsequent eighty time slots). The third channel estimation is performed using DMRS received after the second duplex direction change (e.g., at different locations within the last forty-eight time slots).

[0117] Figure 14 Examples of operational flow / algorithm structures 1400 for configuring DMRS transmission using time slot aggregation are shown according to some implementations. Transmitter devices may implement operational flow / algorithm structures 1400, such as UE 104 or 106, transmitter device 310, or UE 1700 or components thereof, such as processor 1704.

[0118] The operation flow / algorithm structure 1400 may include: at 1402, generating a DMRS configuration for the receiver device for the PSSCH, which indicates that a first DMRS received in a first timeslot can be bundled with a second DMRS received in a second timeslot for channel estimation for the demodulated PSSCH. In the example, timeslot aggregation is used, and the number of timeslots to be aggregated is limited in this configuration. Because timeslot aggregation is used, DMRS bundling is allowed. The bundling size can be defined as a function of the number of timeslots, where the number is less than the number of timeslots configured for timeslot aggregation. The bundling size can also be defined in this configuration.

[0119] The operation flow / algorithm structure 1400 may include: at 1404, sending a configuration to the receiver device. For example, the configuration may be signaled via an RRC message. Further, specific parameters of the configuration or changes to the configuration may be signaled via additional RRC messages and / or SCI messages. In the example, when multiple resource pools are configured, RRC or SCI signaling can be used to indicate resource pool selection (or equivalent, configuration selection) to the receiver UE. This selection may be based on feedback information from the receiver device.

[0120] The operation flow / algorithm structure 1400 may include: at 1406, sending DMRS to the receiver device based on configuration. For example, the DMRS to be sent is mapped to physical resources of the PSSCH according to the configuration, and these physical resources carry the information included in the DMRS.

[0121] Figure 15Examples of operational flow / algorithm structures 1500 for a device to receive DMRS using time slot aggregation, according to some embodiments, are shown. Receiver devices may implement operational flow / algorithm structures 1500, such as UE 104 or 106, receiver device 320, or UE 1700 or components thereof, such as processor 1704.

[0122] The operation flow / algorithm structure 1500 may include: at 1502, determining the DMRS configuration for the PSSCH, which indicates that a first DMRS received in a first timeslot can be bundled with a second DMRS received in a second timeslot for channel estimation for the demodulated PSSCH. In the example, timeslot aggregation is used, and the number of timeslots to be aggregated is limited in this configuration. Because timeslot aggregation is used, DMRS bundling is allowed. The bundle size can be defined as a function of the number of timeslots, where the number is less than the number of timeslots configured for timeslot aggregation. The bundle size can also be defined in this configuration. Further, capability information can be exchanged between the transmitter and receiver devices, and this information can indicate whether each of the two devices is capable of supporting phase continuity. If so, the receiver device determines that the bundle size should be used for channel estimation. Otherwise, the receiver device can determine that the bundle size needs to be allocated into smaller bundle segments. This configuration can be signaled using RRC messages and / or SCI messages. The capability information can be signaled using RRC messages.

[0123] The operation flow / algorithm structure 1500 may include: at 1504, receiving DMRS on the PSSCH based on configuration, receiving a first DMRS in a first time slot, and receiving a second DMRS in a second time slot. In the example, the receiver device is configured to monitor and detect DMRS according to the configuration.

[0124] The operation flow / algorithm structure 1500 may include: at 1506, determining a DMRS measurement based on a first measurement of the first DMRS and a second measurement of the second DMRS. For example, each of the first and second measurements is an RSRP measurement. If two DMRSs belong to the same bundle or bundle segment, the corresponding two measurements can be part of the DMRS measurement. For example, a DMRS measurement is a statistical measure of such measurements (and similarly, other RSRP measurements for DMRSs that need to be bundled).

[0125] The operation flow / algorithm structure 1500 may include: at 1508, performing channel estimation based on DMRS measurements. For example, estimating channel quality from DMRS measurements for demodulating data received in aggregated time slots (or time slot segments corresponding to bundled segments to which DMRS measurements are applied).

[0126] Figure 16 A receiver component 1600 for a UE 104 or 106 according to some embodiments is shown. The receiver component 1600 may include an antenna panel 1604 that includes a plurality of antenna elements. The panel 1604 is shown as having four antenna elements, but other embodiments may include other numbers.

[0127] Antenna panel 1604 can be coupled to an analog beamforming (BF) component comprising multiple phase shifters 1608(1) to 1608(4). Phase shifters 1608(1) to 1608(4) can be coupled to radio frequency (RF) chain 1612. RF chain 1612 can amplify received analog RF signals, down-convert RF signals to baseband, and convert analog baseband signals to digital baseband signals that can be provided to a baseband processor for further processing.

[0128] In various implementations, control circuitry residing in the baseband processor may provide BF weights (e.g., W1 to W4) (which may represent the phase shift values ​​of phase shifters 1608(1) to 1608(4)) to provide a receive beam at antenna panel 1604. These BF weights may be determined based on channel-based beamforming.

[0129] Figure 17 A UE 1700 according to some implementation schemes is shown. UE 1700 may be similar to Figure 1 It can be used with UE 104 or 106, and is basically interchangeable with them.

[0130] Similar to that described above with respect to UE 104 or 106, UE 1700 can be any mobile or non-mobile computing device, such as a mobile phone, computer, tablet, industrial wireless sensors (e.g., microphones, carbon dioxide sensors, pressure sensors, humidity sensors, thermometers, motion sensors, accelerometers, laser scanners, fluid level sensors, stock sensors, voltmeters / ammeters, actuators, etc.), video surveillance / monitoring devices (e.g., cameras, camcorders, etc.), wearable devices, or loosely coupled IoT devices. In some implementations, the UE can be a reduced-capacity UE or an NR-Light UE.

[0131] UE 1700 may include a processor 1704, RF interface circuitry 1708, memory / storage device 1712, user interface 1716, sensor 1720, drive circuitry 1722, power management integrated circuit (PMIC) 1724, and battery 1728. Components of UE 1700 may be implemented as integrated circuits (ICs), portions of integrated circuits, discrete electronic devices or other modules, logic components, hardware, software, firmware, or combinations thereof. Figure 17 The block diagram is intended to show a high-level view of some of the components of the UE 1700. However, some of the components shown may be omitted, additional components may be present, and different arrangements of the components shown may occur in other specific implementations.

[0132] The components of UE 1700 can be coupled to various other components via one or more interconnects 1732, which can represent any type of interface, input / output, bus (local, system, or extension), transmission line, trace, optical connector, etc., allowing various circuit components (on common or different chips or chipsets) to interact with each other.

[0133] Processor 1704 may include processor circuitry such as baseband processor circuitry (BB) 1704A, central processing unit circuitry (CPU) 1704B, and graphics processing unit circuitry (GPU) 1704C. Processor 1704 may include any type of circuitry or processor circuitry that executes or otherwise operates computer-executable instructions, such as program code, software modules, or functional procedures from memory / storage device 1712, to cause UE 1700 to perform the operations described herein.

[0134] In some implementations, the baseband processor circuit 1704A can access the communication protocol stack 1736 in the memory / storage device 1712 to communicate over a 3GPP-compliant network. Generally, the baseband processor circuit 1704A can access the communication protocol stack to perform the following operations: user plane functions at the PHY, MAC, RLC, PDCP, SDAP, and PDU layers; and control plane functions at the PHY, MAC, RLC, PDCP, RRC, and non-access stratum (NAS) layers. In some implementations, PHY layer operations may additionally / optionally be performed by components of the RF interface circuit 1708.

[0135] The baseband processor circuit 1704A can generate or process baseband signals or waveforms carrying information in a 3GPP-compliant network. In some implementations, the waveforms used for NR can be based on cyclic prefix OFDM (CP-OFDM) in the uplink or downlink, and Discrete Fourier Transform Extended OFDM (DFT-S-OFDM) in the uplink.

[0136] The baseband processor circuit 1704A can also access group information from the memory / storage device 1712 to determine multiple repeated search space groups in which the PDCCH can be transmitted.

[0137] Memory / storage device 1712 may include any type of volatile or non-volatile memory that can be distributed throughout the UE 1700. In some embodiments, some memory / storage devices 1712 may be located on the processor 1704 itself (e.g., L1 cache and L2 cache), while other memory / storage devices 1712 may be located external to the processor 1704 but accessible via a memory interface. Memory / storage device 1712 may include any suitable volatile or non-volatile memory, such as, but not limited to, dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory, or any other type of memory device technology.

[0138] RF interface circuitry 1708 may include transceiver circuitry and a radio frequency front-end module (RFEM), which allows UE 1700 to communicate with other devices via a radio access network. RF interface circuitry 1708 may include various components arranged in the transmit or receive path. These components may include, for example, switches, mixers, amplifiers, filters, synthesizer circuitry, control circuitry, etc.

[0139] In the receiving path, the RFEM can receive the radiated signal from the air interface via antenna 1724 and continue to filter and amplify the signal (using a low-noise amplifier). This signal can be provided to the receiver of the transceiver, which downconverts the RF signal into a baseband signal that is provided to the baseband processor of processor 1704.

[0140] In the transmission path, the transceiver's transmitter upconverts the baseband signal received from the baseband processor and provides the RF signal to the RFEM. The RFEM amplifies the RF signal via a power amplifier before it is radiated across the air interface via antenna 1724.

[0141] In various implementations, the RF interface circuit 1708 can be configured to transmit / receive signals in a manner compatible with NR access technology.

[0142] Antenna 1724 may include multiple antenna elements, each of which converts an electrical signal into radio waves to travel through the air and converts received radio waves back into electrical signals. These antenna elements may be arranged in one or more antenna panels. Antenna 1724 may have omnidirectional, directional, or combinations thereof antenna panels to enable beamforming and multiple-input / multiple-output communication. Antenna 1724 may include a microstrip antenna, a printed antenna fabricated on the surface of one or more printed circuit boards, a patch antenna, a phased array antenna, etc. Antenna 1724 may have one or more panels designed for a specific frequency band including the band in FR1 or FR2.

[0143] User interface circuitry 1716 includes various input / output (I / O) devices designed to enable users to interact with UE 1700. User interface 1716 includes input device circuitry and output device circuitry. Input device circuitry includes any physical or virtual means for accepting input, particularly including one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, a keypad, a mouse, a touchpad, a touchscreen, a microphone, a scanner, a headset, etc. Output device circuitry includes any physical or virtual means for displaying information or otherwise conveying information, such as sensor readings, actuator positions, or other similar information. Output device circuitry may include any number or combination of audio or visual displays, particularly including one or more simple visual outputs / indicators (e.g., binary status indicators such as light-emitting diodes (LEDs) and multi-character visual outputs), or more complex outputs such as display devices or touchscreens (e.g., liquid crystal displays (LCDs), LED displays, quantum dot displays, projectors, etc.), where the output of characters, graphics, multimedia objects, etc., is generated or produced by the operation of UE 1700.

[0144] Sensor 1720 may include devices, modules, or subsystems intended to detect events or changes in their environment and transmit information about the detected events (sensor data) to other devices, modules, subsystems, etc. Examples of such sensors include, in particular: inertial measurement units including accelerometers; gyroscopes; or magnetometers; microelectromechanical systems (MEMS) or nanoelectromechanical systems (NEMS) including triaxial accelerometers; triaxial gyroscopes; or magnetometers; level sensors; flow sensors; temperature sensors (e.g., thermistors); pressure sensors; barometric pressure sensors; gravimeters; altimeters; image capture devices (e.g., cameras or lensless aperture sensors); light detection and ranging sensors; proximity sensors (e.g., infrared radiation detectors, etc.); depth sensors; ambient light sensors; ultrasonic transceivers; microphones or other similar audio capture devices; etc.

[0145] The driving circuitry 1722 may include software and hardware elements for controlling specific devices embedded in, attached to, or otherwise communicatively coupled to the UE 1700. The driving circuitry 1722 may include various drivers that allow other components to interact with or control various input / output (I / O) devices that may exist within or be connected to the UE 1700. For example, the driving circuitry 1722 may include: a display driver for controlling and allowing access to a display device; a touchscreen driver for controlling and allowing access to a touchscreen interface; a sensor driver for acquiring sensor readings of the sensor circuitry 1720 and controlling and allowing access to the sensor circuitry 1720; a driver for acquiring actuator positions of electromechanical components or controlling and allowing access to electromechanical components; a camera driver for controlling and allowing access to an embedded image capture device; and an audio driver for controlling and allowing access to one or more audio devices.

[0146] The PMIC 1724 manages the power supplied to various components of the UE 1700. In particular, relative to the processor 1704, the PMIC 1724 controls power selection, voltage scaling, battery charging, or DC-DC conversion.

[0147] In some implementations, the PMIC 1724 can control or otherwise become part of various power-saving mechanisms of the UE 1700. For example, if the platform UE is in the RRC_Connected state, where it remains connected to the RAN node as it anticipates receiving traffic soon, it can enter a state known as Discontinuous Receive Mode (DRX) after a period of inactivity. During this state, the UE 1700 can power down for short intervals to save power. If there is no data traffic activity over an extended period, the UE 1700 can transition to the RRC_Idle state, where the platform disconnects from the network and does not perform operations such as channel quality feedback, handover, etc. The UE 1700 enters a very low-power state and performs paging, where the platform periodically wakes up again to listen to the network and then power down again. The UE 1700 may not receive data in this state; to receive data, the platform must transition back to the RRC_Connected state. Additional power-saving modes can allow the device to be unable to use the network for longer than the paging interval (ranging from a few seconds to several hours). During this period, the device is completely unable to connect to the network and can be completely powered off. Any data sent during this time will result in significant latency, which is assumed to be acceptable.

[0148] Battery 1728 can power UE 1700, but in some examples, UE 1700 may be mounted in a fixed location and may have a power source coupled to the mains. Battery 1728 may be a lithium-ion battery, a metal-air battery such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, etc. In some specific implementations, such as in vehicle-based applications, battery 1728 may be a typical lead-acid automotive battery.

[0149] Figure 18 A gNB 1800 according to some implementation schemes is shown. The gNB node 1800 may be similar to the gNB 108 and is essentially interchangeable with it. The base station may have the same or similar components as the gNB 1800.

[0150] The gNB 1800 may include a processor 1804, an RF interface circuit 1808, a core network (CN) interface circuit 1812, and a memory / storage device circuit 1816.

[0151] The gNB 1800 components can be coupled to various other components via one or more interconnects 1828.

[0152] The processor 1804, RF interface circuit 1808, memory / storage device circuit 1816 (including communication protocol stack 1810), antenna 1824, and interconnector 1828 can be similar to those described above. Figure 16 Similar named elements are shown and described.

[0153] The CN interface circuit 1812 can provide connectivity to a core network (e.g., a 5GC using a 5G core network (5GC) compatible network interface protocol, such as Carrier Ethernet, or some other suitable protocol). Network connectivity can be provided to / from the gNB 1800 via fiber optic or wireless backhaul. The CN interface circuit 1812 may include one or more dedicated processors or FPGAs for communicating using one or more of the aforementioned protocols. In some implementations, the CN interface circuit 1812 may include multiple controllers for providing connectivity to other networks using the same or different protocols.

[0154] As is widely recognized, the use of personally identifiable information should comply with privacy policies and practices that are generally accepted to meet or exceed industry or governmental requirements for protecting user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly explained to users.

[0155] For one or more embodiments, at least one of the components shown in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, or methods as described in the Examples section below. For example, the baseband circuitry described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the Examples below. As another example, the circuitry described above in conjunction with one or more of the foregoing figures, associated with a UE, base station, network element, etc., may be configured to operate according to one or more embodiments described in the Examples section below.

[0156] Example

[0157] Further exemplary implementations are provided in the following sections.

[0158] Example 1 includes a method. This method is implemented on a device. The method includes: determining a demodulation reference signal (DMRS) configuration for a Physical Side Link Shared Channel (PSSCH), the configuration indicating a Code Division Multiplexing (CDM) group associated with a plurality of antenna ports, the plurality of antenna ports including more than two antenna ports; receiving the DMRS on the PSSCH based on the configuration using the plurality of antenna ports, the DMRS being received in resource elements (REs) corresponding to the CDM group; and performing channel estimation for the demodulated PSSCH based on the DMRS.

[0159] Example 2 includes the method according to Example 1, wherein the CDM group is a first CDM group and the plurality of antenna ports are a first plurality of antenna ports, wherein a configuration indicates a second CDM group associated with a second plurality of ports, and wherein the first CDM group is orthogonal to the second CDM group.

[0160] Example 3 includes the method according to any one of Examples 1 to 2 above, wherein the plurality of antenna ports includes four antenna ports, and wherein the CDM group includes four REs corresponding to the four antenna ports respectively.

[0161] Example 4 includes the method according to any one of Examples 1 to 3 above, wherein the CDM group is a first CDM group, and the configuration indicates a second CDM group and whether the second CDM group is used for DMRS transmission.

[0162] Example 5 includes the method according to Example 4, wherein PSSCH rate matching is performed based on the first CDM group and the second CDM group, independent of whether the second CDM group is used for DMRS transmission to the device.

[0163] Example 6 includes the method according to any one of Examples 1 to 5 above, wherein the CDM group is a first CDM group for a first DMRS transmission to the device, wherein the configuration indicates a second CDM group and whether the second CDM group is used for a second DMRS transmission, wherein the power spectral density (PSD) of the first DMRS transmission is increased by a first factor.

[0164] Example 7 includes the method according to Example 6, wherein the first factor is equal to the total number of CDM groups indicated in the configuration divided by the total number of CDM groups used for DMRS transmission to the device.

[0165] Example 8 includes the method according to any one of Examples 1 to 7 above, wherein the CDM group is a first CDM group for a first DMRS transmission to the device, wherein a configuration indicates a second CDM group and that the second CDM group is not used for a second DMRS transmission to the device, wherein the power spectral density (PSD) of the first DMRS transmission is increased by a first factor of at least two.

[0166] Example 9 includes the method according to any one of Examples 1 to 8, wherein the configuration indicates a single symbol DMRS.

[0167] Example 10 includes the method according to any one of Examples 1 to 8 above, wherein the configuration indicates multi-symbol DMRS and the configuration is received in a first signaling, and wherein the method further includes: receiving a second signaling indicating DMRS transmission associated with a CDM group; and using single-symbol DMRS.

[0168] Example 11 includes the method according to any one of Examples 1 to 10 above, wherein the device is a first device, and wherein the method further includes: sending information indicating sidelink quality or a recommended DMRS configuration based on the sidelink quality to a second device, wherein the configuration is received from the second device based on the information.

[0169] Example 12 includes the method according to Example 11, wherein the recommended DMRS configuration includes at least one of the following: the number of DMRS symbols per location, the number of DMRS locations within a time slot, or whether it is necessary to increase the power spectral density (PSD) for DMRS transmission.

[0170] Example 13 includes the method according to any one of Examples 1 to 12 above, wherein the configuration further indicates a plurality of DMRS locations in the time slot, the plurality of DMRS locations including more than four locations, and wherein DMRS received at the plurality of DMRS locations is received.

[0171] Example 14 includes the method according to any one of Examples 1 to 13 above, wherein the configuration further indicates that a first DMRS received in a first time slot can be bundled with a second DMRS received in a second time slot for channel estimation.

[0172] Example 15 includes a method. This method is implemented on a device. The method includes: determining a configuration of a demodulation reference signal (DMRS) for a physical side-link shared channel (PSSCH), the configuration indicating multiple DMRS locations in a time slot, the multiple DMRS locations including more than four locations; receiving the DMRS on the PSSCH based on the configuration, the DMRS being received at the multiple DMRS locations; and performing channel estimation for the demodulated PSSCH based on the DMRS.

[0173] Example 16 includes the method according to Example 15, wherein the configuration further indicates whether to increase the power spectral density (PSD) of the DMRS transmission.

[0174] Example 17 includes the method according to Example 16, wherein, based on a configuration indicating that no data symbol transmission is occurring on the second subcarrier at the first location, the PSD is instructed to enhance the transmission of the first DMRS symbol on the first subcarrier at the first location in the time domain.

[0175] Example 18 includes the method according to Example 16, wherein, based on the configuration indicating the transmission of data symbols on the second subcarrier at the first location, the PSD is instructed not to enhance the transmission of the first DMRS symbol on the first subcarrier at the first location in the time domain.

[0176] Example 19 includes the method according to any one of Examples 15 to 18 above, wherein the configuration is used for resource pools from multiple resource pools, wherein the multiple resource pools have different corresponding configurations.

[0177] Example 20 includes the method according to Example 19, wherein the configuration is a configuration of a resource pool and differs from another configuration of another resource pool in at least one of the following: time-domain mode density, number of DMRS symbols per time-domain location, whether DMRS power enhancement density is allowed, and DMRS type based on the number of code division multiplexing (CDM) groups or orthogonal overlay code (OCC) mode.

[0178] Example 21 includes the method according to Example 19, wherein multiple resource pools are configured for different corresponding coverage areas.

[0179] Example 22 includes the method according to Example 21, wherein different coverage ranges are based on path loss or reference signal received power (RSRP) measurements between devices.

[0180] Example 23 includes the method described in Example 19, wherein the resource pool is a fallback resource pool that the device monitors based on: time period, communication loss, receive DMRS failure, perform channel estimation failure, path loss, or reference signal received power (RSRP) measurement.

[0181] Example 24 includes the method according to any one of Examples 15 to 23 above, wherein the configuration further indicates a code division multiplexing (CDM) group associated with a plurality of antenna ports, wherein the plurality of antenna ports include more than two antenna ports, wherein DMRS is received in a resource element (RE) corresponding to the CDM group by using the plurality of antenna ports.

[0182] Example 25 includes the method according to any one of Examples 15 to 24 above, wherein the configuration further indicates that a first DMRS received in a first time slot can be bundled with a second DMRS received in a second time slot for channel estimation.

[0183] Example 26 includes a method. This method is implemented on a device. The method includes: determining a configuration for a demodulation reference signal (DMRS) for a physical side-link shared channel (PSSCH), the configuration indicating that a first DMRS received in a first timeslot can be bundled with a second DMRS received in a second timeslot for channel estimation for the demodulated PSSCH; receiving the DMRS on the PSSCH based on the configuration, the first DMRS being received in the first timeslot and the second DMRS being received in the second timeslot; determining DMRS measurements based on a first measurement of the first DMRS and a second measurement of the second DMRS; and performing channel estimation based on the DMRS measurements.

[0184] Example 27 includes the method according to Example 26, wherein the configuration includes a DMRS time-domain bundling size indicating the number of time slots that can be bundled for channel estimation.

[0185] Example 28 includes the method according to any one of Examples 26 to 27 above, wherein the device is a first device, wherein the configuration is received from a second device, and wherein the operation further includes: sending capability information to the second device indicating whether the first device is able to maintain phase continuity when the duplex direction changes, wherein the configuration is based on the capability information.

[0186] Example 29 includes the method according to any one of Examples 26 to 28 above, wherein the device is a first device, wherein the configuration is received from a second device, and the configuration is received based on the ability of the second device to maintain phase continuity when the duplex direction changes.

[0187] Example 30 includes the method according to any one of Examples 26 to 29 above, wherein the configuration includes a first DMRS time-domain bundle size indicating the total number of time slots that can be bundled for channel estimation, wherein the device is unable to maintain phase continuity when the duplex direction changes, and wherein the operation further includes: determining a second DMRS time-domain bundle size that is larger than the first DMRS time-domain bundle size, wherein the difference between the number of time slots of the first time slot and the number of time slots of the second time slot is within the second DMRS time-domain bundle size.

[0188] Example 31 includes the method according to any one of Examples 26 to 30 above, wherein the configuration further indicates a code division multiplexing (CDM) group associated with a plurality of antenna ports, wherein the plurality of antenna ports include more than two antenna ports, wherein DMRS is received in a resource element (RE) corresponding to the CDM group by using the plurality of antenna ports.

[0189] Example 32 includes the method according to any one of Examples 26 to 31 above, wherein the configuration further indicates a plurality of DMRS locations in the time slot, the plurality of DMRS locations including more than four locations, and wherein DMRS received at the plurality of DMRS locations is received.

[0190] Example 33 includes an apparatus comprising means for performing one or more elements of the methods described or associated with any of Examples 1 to 32.

[0191] Example 34 includes one or more computer-readable media storing instructions that, when executed by a device, cause the device to perform the operations of the methods described or associated with any of Examples 1 to 32.

[0192] Example 35 includes an apparatus comprising logic components, modules, or circuitry for performing one or more elements of the methods described or associated with any of Examples 1 to 32.

[0193] Example 36 includes an apparatus comprising one or more processors and one or more computer-readable media, the one or more computer-readable media including instructions that, when executed by the one or more processors, configure the apparatus to perform any of the embodiments of Examples 1 to 32.

[0194] Unless otherwise expressly stated, any of the examples above may be combined with any other example (or combination of examples). The foregoing description of one or more specific embodiments provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. In light of the teachings above, modifications and variations are possible, or modifications and variations may be derived from practice of various embodiments.

[0195] Although the above embodiments have been described in considerable detail, many variations and modifications will become apparent to those skilled in the art once the disclosure is fully understood. This disclosure is intended to render the following claims as encompassing all such variations and modifications.

Claims

1. A method for wireless communication, executed by one or more processors, the method comprising: Send information to network nodes indicating whether the ability to maintain phase continuity is supported when the duplex direction changes; A configuration for a demodulation reference signal (DMRS) for a physical channel is determined, the configuration indicating that a first DMRS received in a first time slot can be bundled with a second DMRS received in a second time slot for channel estimation for demodulating the physical channel, the configuration being based on the capability information; The DMRS is processed based on the configuration, the first DMRS received in the first time slot, and the second DMRS received in the second time slot; The DMRS measurement is determined based on a first measurement of the first DMRS and a second measurement of the second DMRS. as well as The channel estimation is performed based on the DMRS measurements.

2. The method of claim 1, wherein the configuration includes DMRS time-domain bundle size.

3. The method of claim 1, wherein the configuration is received based on the network node’s ability to maintain phase continuity when the duplex direction changes.

4. The method of claim 1, wherein the configuration includes a first DMRS time-domain bundling size indicating the total number of time slots that can be bundled for the channel estimation.

5. The method of claim 1, wherein the method is implemented on a device that cannot maintain phase continuity when the duplex direction changes.

6. The method according to claim 5, further comprising: A second DMRS time-domain bundle size is determined that is smaller than the first DMRS time-domain bundle size, wherein the difference between the number of time slots in the first time slot and the number of time slots in the second time slot is within the second DMRS time-domain bundle size.

7. The method according to claim 1, further comprising: Send information to the network node indicating sidelink quality or a recommended DMRS configuration based on the sidelink quality.

8. The method of claim 7, wherein the configuration is received from the network node based on the information, wherein the recommended DMRS configuration includes at least one of the following: the number of DMRS symbols per location, the number of DMRS locations in a time slot, or whether it is necessary to increase the power spectral density (PSD) for DMRS transmission.

9. The method of claim 1, wherein the configuration further indicates a plurality of DMRS locations in the second time slot, the plurality of DMRS locations including more than four locations.

10. The method of claim 1, wherein the configuration further indicates whether to increase the power spectral density (PSD) of the DMRS transmission.

11. The method of claim 1, wherein the configuration corresponds to a resource pool from a plurality of resource pools, wherein the plurality of resource pools have different corresponding configurations and are used for different coverage areas.

12. An apparatus for wireless communication, comprising: One or more processors; and Memory, storing instructions that, when executed by the one or more processors, cause the method according to any one of claims 1-11 to be performed.

13. A computer-readable storage medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform the method according to any one of claims 1-11.

14. A computer program product comprising a computer program including instructions which, when executed on a device, cause the device to perform the method according to any one of claims 1 to 11.

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