DMRS indication method and apparatus

Abstract

The present application relates to the field of communications. Provided are a DMRS indication method and apparatus. The method comprises: a network device configuring a same time-domain resource for DMRSs of different terminal devices; and if the DMRSs of two terminal devices are not orthogonal, the network device changing the position of the time-domain resource of one of the terminal devices, so as to reduce the probability of mutual interference between the two terminal devices. The present application is beneficial to improving the accuracy of channel estimation.

Description

DMRS indication method and apparatus

[0001] This application claims priority to Chinese Patent Application No. 202411945246.6, filed on December 24, 2024, entitled “Indication Method and Apparatus for DMRS”, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communications, and in particular to a method and apparatus for indicating DMRS. Background Technology

[0003] With the development of communication technology, network equipment can deploy more large-scale array antennas, which is conducive to supporting higher spatial degrees of freedom, thereby enabling cross-system multi-user multiple input multiple output (MU-MIMO) between different communication networks.

[0004] For example, network devices can schedule the 5G physical downlink shared channel (5G PDSCH) and the PDSCH of future communication networks on the same time-frequency resources at different spatial division ports, which is beneficial to improving the utilization efficiency of spectrum resources. Terminal devices using 5G communication networks can estimate the channel based on the demodulation reference signal (DMRS) in the 5G PDSCH, thereby demodulating the 5G PDSCH to obtain downlink data. Similarly, terminal devices using future communication networks can estimate the channel based on the DMRS in the PDSCH of the future communication network, thereby demodulating the PDSCH of the future communication network to obtain downlink data.

[0005] However, this approach may cause mutual interference between terminal devices using different communication networks during channel estimation, reducing the accuracy of channel estimation. Summary of the Invention

[0006] This application provides a DMRS indication method and apparatus, which helps to improve the accuracy of channel estimation.

[0007] Firstly, a DMRS indication method is provided. This method can be executed by a terminal-side communication device, or by other entities, without limitation in this application. The terminal-side communication device can be a first terminal device, or a functional module, communication module, chip, chip system, or circuit (such as a modem chip, also known as a baseband chip, or a system-on-chip (SoC) chip containing a modem core, or a system-in-package (SIP) chip) within the first terminal device. For ease of description, the first terminal device will be used as an example below.

[0008] The method may include: receiving configuration information, the configuration information being used to determine that the first DMRS is located at a first symbol position; receiving first information, the first information being used to determine that the first DMRS is located at a second symbol position, the second symbol position being located in the same time unit as the first symbol position, the second symbol position being used to receive the first DMRS.

[0009] The DMRS indication method provided in this application can determine to receive the first DMRS at the second symbol position based on the first information, instead of receiving the first DMRS at the first symbol position, which helps to reduce the impact on other terminal equipment and improve the accuracy of channel estimation.

[0010] In one possible implementation, the first symbol position and the second symbol position satisfy one or more of the following: the first symbol position is adjacent to the second symbol position; or, the first symbol position is after the second symbol position; or, the first symbol position is before the second symbol position; or, the first symbol position and the second symbol position are separated by one symbol.

[0011] In one possible implementation, the first DMRS is used for data demodulation of the first PDSCH of the first terminal device, the first information indicates that the second PDSCH of the second terminal device is spatially multiplexed with the first PDSCH, the first terminal device adopts a first radio access technology (RAT), and the second terminal device adopts a second RAT.

[0012] In this implementation, the first terminal device can detect that a second terminal device occupies the same symbol position as the first terminal device. In order to reduce interference, the first terminal device can determine a new symbol position (i.e., the second symbol position).

[0013] In one possible implementation, the first information indicates the offset of the second symbol position relative to the first symbol position.

[0014] In this implementation, the first terminal device receives the offset of the second symbol position relative to the first symbol position, and determines the position of the second symbol based on the offset, which is simple to implement.

[0015] In one possible implementation, the first information indicates a bitmap of P bits, and the second symbol position is the symbol position corresponding to the bit with a first value among the P bits, where P is the number of symbols included in the time unit.

[0016] In this way, the position of the second symbol can be determined by a bitmap of P bits, which simplifies the parsing process and helps reduce the error rate of parsing.

[0017] In one possible implementation, the first DMRS is used for data demodulation of the first PDSCH, and the frequency domain resources of the first symbol location are unavailable for the first PDSCH.

[0018] In this way, the first symbol position is occupied by other terminal devices, and the first PDSCH does not occupy the frequency domain resources of the first symbol position. This is equivalent to rate matching of the first symbol position, which helps to reduce interference to other terminal devices.

[0019] In one possible implementation, the first DMRS is used for data demodulation of the first PDSCH, and the configuration information is also used to determine the third symbol position, which overlaps with the first symbol position in the time domain. If the third symbol position is not available for the first PDSCH, then the second symbol position does not overlap with the third symbol position in the time domain.

[0020] The overlap of the third symbol position with the first symbol position in the time domain indicates that the overlapping time-domain resources have two uses: one corresponding to the first symbol position and the other to the third symbol position. If the third symbol position is unavailable for the first PDSCH, it suggests that the overlapping time-domain resources may cause interference due to their dual uses. In this case, the first DMRS can occupy the second symbol position, which does not overlap with the third symbol position in the time domain. This allows the overlapping time-domain resources to have only the use of the third symbol position, while the time-domain resources at the second symbol position can have the use of the first symbol position, which helps reduce interference.

[0021] In one possible implementation, the third symbol position and the first symbol position have non-overlapping frequency domain resources and overlapping frequency domain resources. The non-overlapping frequency domain resources are available to the first PDSCH, while the overlapping frequency domain resources are not available to the first PDSCH.

[0022] Overlapping frequency domain resources are unavailable to the first PDSCH, which helps reduce interference, while non-overlapping frequency domain resources are available to the first PDSCH, which helps increase the available resources of the PDSCH.

[0023] In one possible implementation, the method further includes: receiving information indicating the type of at least one code division multiplexing (CDM) group and at least one CDM group; and determining overlapping frequency domain resources based on the type of at least one CDM group and at least one CDM group.

[0024] In one possible implementation, the third symbol position is the symbol position of the second DMRS, the second DMRS is used for data demodulation of the second PDSCH of the second terminal device, the first DMRS is used for data demodulation of the first PDSCH of the first terminal device, the first terminal device uses the first RAT, and the second terminal device uses the second RAT.

[0025] In one possible implementation, the first DMRS includes a pre-DMRS and / or an additional DMRS.

[0026] Secondly, a method for indicating DMRS is provided. This method can be executed by a network-side communication device, or by other entities, without limitation in this application. The network-side communication device can be a network device, or a functional module, communication module, chip, chip system, or circuit (such as a modem chip, also known as a baseband chip, or a SoC chip or SIP chip containing a modem core) within the network device. For ease of description, a network device will be used as an example below.

[0027] The method may include: sending configuration information, the configuration information being used to determine that the first demodulation reference signal DMRS is located at a first symbol position; sending first information, the first information being used to determine that the first DMRS is located at a second symbol position, the second symbol position being located in the same time unit as the first symbol position, the second symbol position being used to receive the first DMRS.

[0028] In one possible implementation, the first symbol position and the second symbol position satisfy one or more of the following: the first symbol position is adjacent to the second symbol position; or, the first symbol position is after the second symbol position; or, the first symbol position is before the second symbol position; or, the first symbol position and the second symbol position are separated by one symbol.

[0029] In one possible implementation, the first DMRS is used for data demodulation of the first physical downlink data channel (PDSCH) of the first terminal device, the first information indicates that the second PDSCH of the second terminal device is spatially multiplexed with the first PDSCH, the first terminal device uses a first RAT, and the second terminal device uses a second RATRAT.

[0030] In one possible implementation, the first information indicates the offset of the second symbol position relative to the first symbol position.

[0031] In one possible implementation, the first information indicates a bitmap of P bits, and the second symbol position is the symbol position corresponding to the bit with a first value among the P bits, where P is the number of symbols included in the time unit.

[0032] In one possible implementation, the first DMRS is used for data demodulation of the first PDSCH, and the frequency domain resources of the first symbol location are unavailable for the first PDSCH.

[0033] In one possible implementation, the first DMRS is used for data demodulation of the first PDSCH, and the configuration information is also used to determine the third symbol position, which overlaps with the first symbol position in the time domain. If the third symbol position is not available for the first PDSCH, then the second symbol position does not overlap with the third symbol position in the time domain.

[0034] In one possible implementation, the third symbol position and the first symbol position have non-overlapping frequency domain resources and overlapping frequency domain resources. The non-overlapping frequency domain resources are available to the first PDSCH, while the overlapping frequency domain resources are not available to the first PDSCH.

[0035] In one possible implementation, the method further includes: sending information indicating the type of at least one code division multiplexing (CDM) group and at least one CDM group, the type of the at least one CDM group being used to determine overlapping frequency domain resources.

[0036] In one possible implementation, the third symbol position is the symbol position of the second DMRS, the second DMRS is used for data demodulation of the second PDSCH of the second terminal device, the first DMRS is used for data demodulation of the first PDSCH of the first terminal device, the first terminal device uses the first RAT, and the second terminal device uses the second RAT.

[0037] In one possible implementation, the first DMRS includes a pre-DMRS and / or an additional DMRS.

[0038] Thirdly, a communication apparatus is provided for executing the method in any of the possible implementations of the above aspects. Specifically, the communication apparatus includes a module for executing the method in any of the possible implementations of the above aspects.

[0039] Fourthly, another communication device is provided, including a processor coupled to a memory for executing instructions in the memory to implement the methods in any of the possible implementations of the foregoing aspects. Optionally, the communication device further includes a memory. Optionally, the communication device further includes a communication interface to which the processor is coupled.

[0040] In one implementation, the communication device is a first terminal device or a network device. When the communication device is a first terminal device or a network device, the communication interface can be a transceiver or an input / output interface.

[0041] In another implementation, the communication device is a chip applicable to the first terminal device or a chip in a network device. When the communication device is a chip applicable to the first terminal device or a chip in a network device, the communication interface can be an input / output interface.

[0042] Fifthly, a processor is provided, comprising: an input circuit, an output circuit, and a processing circuit. The processing circuit is used to receive signals through the input circuit and transmit signals through the output circuit, causing the processor to execute the method in any possible implementation of the above aspects.

[0043] In the specific implementation process, the processor can be a chip, the input circuit can be an input pin, the output circuit can be an output pin, and the processing circuit can be a transistor, gate circuit, flip-flop, and various logic circuits. The input signal received by the input circuit can be received and input by, for example, but not limited to, a receiver, and the signal output by the output circuit can be output to, for example, but not limited to, a transmitter and transmitted by the transmitter. Furthermore, the input circuit and the output circuit can be the same circuit, which is used as the input circuit and the output circuit at different times. This application does not limit the specific implementation of the processor and various circuits.

[0044] Fifthly, a communication device is provided, including a processor and a memory. The processor is used to read instructions stored in the memory and to receive signals via a receiver and transmit signals via a transmitter to execute the methods in any of the possible implementations of the above aspects.

[0045] Optionally, the processor may be one or more, and the memory may be one or more.

[0046] Optionally, the memory may be integrated with the processor, or the memory may be separated from the processor.

[0047] In the specific implementation process, the memory can be a non-transitory memory, such as read-only memory (ROM), which can be integrated with the processor on the same chip or set on different chips. This application does not limit the type of memory or the way the memory and processor are set.

[0048] It should be understood that the relevant data interaction process, such as sending instruction information, can be a process of outputting instruction information from the processor, and receiving capability information can be a process of the processor receiving input capability information. Specifically, the processed output data can be output to the transmitter, and the input data received by the processor can come from the receiver. Here, the transmitter and receiver can be collectively referred to as transceivers.

[0049] The communication device in the fifth aspect above can be a chip. The processor can be implemented in hardware or software. When implemented in hardware, the processor can be a logic circuit, integrated circuit, etc. When implemented in software, the processor can be a general-purpose processor that reads software code stored in memory. The memory can be integrated into the processor or located outside the processor and exist independently.

[0050] In a sixth aspect, a computer program product is provided, the computer program product comprising: a computer program (also referred to as code or instructions), which, when run, causes a computer to perform a method in any of the possible implementations of the foregoing aspects.

[0051] In a seventh aspect, a computer-readable storage medium is provided that stores a computer program (also referred to as code or instructions) that, when executed on a computer, causes the computer to perform the methods in any of the possible implementations of the foregoing aspects.

[0052] It should be understood that the third to seventh aspects of this application correspond to the technical solutions of the first and second aspects of this application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation are similar, and will not be repeated here. Attached Figure Description

[0053] Figure 1 is a schematic diagram of the architecture of a communication system provided in an embodiment of this application;

[0054] Figure 2 is a schematic diagram of a DMRS that occupies a single symbol;

[0055] Figure 3 is a schematic diagram of a DMRS that occupies two symbols;

[0056] Figure 4 is a schematic diagram showing the changes in the number and position of DMRS occupying a single symbol when the number of symbols occupied by a PDSCH is different;

[0057] Figure 5 is a schematic diagram showing the changes in the number and position of DMRS occupying two symbols when the number of symbols occupied by a PDSCH is different;

[0058] Figure 6 is a schematic diagram of the time-frequency distribution of the antenna ports supported by DMRS occupying a single symbol when the DMRS configuration type is type 1;

[0059] Figure 7 is a schematic diagram of the time-frequency distribution of the antenna ports supported by DMRS occupying two symbols when the DMRS configuration type is type 1;

[0060] Figure 8 is a schematic diagram of the time-frequency distribution of the antenna ports supported by DMRS occupying a single symbol when the DMRS configuration type is type 2;

[0061] Figure 9 is a schematic diagram of the time-frequency distribution of the antenna ports supported by DMRS occupying two symbols when the DMRS configuration type is type 2;

[0062] Figure 10 is a schematic diagram comparing the FD-OCC length of DMRS in different versions;

[0063] Figure 11 is another schematic diagram comparing the FD-OCC length of DMRS in different versions;

[0064] Figure 12 is a comparison chart of 5G DMRS and DMRS in future communication networks;

[0065] Figure 13 is a comparison chart of another type of 5G DMRS and DMRS in future communication networks;

[0066] Figure 14 is a schematic diagram of an RB symbol-level rate-matched time-frequency format pattern;

[0067] Figure 15 is a schematic diagram of a RE symbol-level rate-matched time-frequency format pattern;

[0068] Figure 16 is a schematic interactive diagram of a DMRS indication method provided in an embodiment of this application;

[0069] Figure 17 is a schematic diagram of a symbol position change provided in an embodiment of this application;

[0070] Figure 18 is a schematic diagram of the frequency domain resource occupancy of a first symbol position according to an embodiment of this application;

[0071] Figure 19 is a schematic block diagram of a communication device provided in an embodiment of this application;

[0072] Figure 20 is a schematic block diagram of another communication device provided in an embodiment of this application;

[0073] Figure 21 is a schematic block diagram of a processor provided in an embodiment of this application;

[0074] Figure 22 is a schematic diagram of a chip system of a terminal device provided in an embodiment of this application;

[0075] Figure 23 is a schematic diagram of an access network device provided in an embodiment of this application. Detailed Implementation

[0076] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0077] In the embodiments of this application, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and purpose. For example, "first terminal device" and "second terminal device" are used only to distinguish different terminal devices and do not limit their order of execution. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that "first" and "second" do not necessarily imply that they are different.

[0078] It should be noted that, in the embodiments of this application, the words "exemplarily" or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design scheme described as "exemplarily" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of the words "exemplarily" or "for example" is intended to present the relevant concepts in a specific manner.

[0079] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, ab, a--c, bc, or abc, where a, b, and c can be single or multiple.

[0080] In the embodiments of this application, the terms and English abbreviations, such as configuration information and time unit, are merely exemplary examples given for ease of description and should not constitute any limitation on this application. This application does not preclude the possibility of defining other terms that can achieve the same or similar functions in existing or future agreements.

[0081] In the embodiments of this application, the “protocol” may refer to standard protocols in the field of communication, such as LTE protocol, NR protocol, WLAN protocol and related protocols applied to future communication systems. This application does not limit this.

[0082] In the embodiments of this application, "predefined" or "predefined" can be a protocol definition. "Predefined" or "predefined" can be implemented by pre-storing corresponding codes, tables, or other means of indicating relevant information in the device (e.g., including the sending end and the receiving end). This application does not limit the specific implementation method.

[0083] The technical solutions of this application embodiment can be applied to various communication systems, such as: Long Term Evolution (LTE) systems, such as LTE Frequency Division Duplex (FDD) systems and LTE Time Division Duplex (TDD) systems, 5th Generation (5G) systems or New Radio (NR) systems, future communication systems, etc.

[0084] The terminal equipment in this application embodiment can also be referred to as: user equipment (UE), mobile station (MS), mobile terminal (MT), access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication equipment, user agent, or user device, etc.

[0085] The network device involved in this application can be a device that communicates with terminal devices. The network device can also be called an access network device or a wireless access network device. It can be a TRP, an evolved NodeB (eNB or eNodeB) in an LTE system, a home base station (e.g., home evolved NodeB or home Node B, HNB), a base band unit (BBU), a wireless controller in a cloud radio access network (CRAN) scenario, or a relay station, access point, vehicle-mounted device, wearable device, and network device in a 5G network or a network device in a future evolved PLMN network, etc. It can also be an access point (AP) in a WLAN, or a gNB in ​​an NR system. The above-mentioned network devices can also be city base stations, micro base stations, pico base stations, femto base stations, etc. The embodiments of this application do not limit this.

[0086] To facilitate understanding of the embodiments of this application, the communication system applicable to the embodiments of this application will be described in detail first with reference to FIG1.

[0087] Figure 1 is a schematic diagram of the architecture of a communication system provided in an embodiment of this application. As shown in Figure 1, the communication system includes a network device 110, a terminal device 120, and a terminal device 130. The terminal device 120 can communicate with the network device 110 using a 5G communication network, and the terminal device 130 can communicate with the network device 110 using a future communication network.

[0088] Network device 110 can deploy a larger number of large-scale array antennas, which is beneficial for supporting higher spatial division multiplexing (SDM) degrees of freedom, thereby enabling terminal devices 120 and 130 to achieve cross-standard MU-MIMO. For example, the PDSCH configured by network device 110 for terminal device 120 can be called a 5G PDSCH, and the PDSCH configured by network device 110 for terminal device 130 can be called a PDSCH for the future communication network. Network device 110 can schedule the 5G PDSCH and the PDSCH of the future communication network on the same time-frequency resources on different spatial division ports, which is beneficial for improving the utilization efficiency of spectrum resources.

[0089] In this way, terminal device 120 can estimate the channel based on DMRS in the 5G PDSCH, and then demodulate the 5G PDSCH to obtain downlink data. Terminal device 130 can estimate the channel based on DMRS in the PDSCH of a future communication network, and then demodulate the PDSCH of the future communication network to obtain downlink data.

[0090] In this communication system, terminal devices 120 and 130 can communicate on the same time-frequency resources through spatial multiplexing, which can be referred to as 5G and future communication network spectrum sharing. This 5G and future communication network spectrum sharing can also be called dynamic spectrum sharing (DSS) or multi-RAT spectrum sharing (MRSS), and this embodiment does not limit the specific terminology. After the MRSS function is enabled in the cell covered by network device 110, both terminal devices 120 and 130 can access the cell and communicate with network device 110.

[0091] However, this approach may cause mutual interference between terminal devices 120 and 130 during channel estimation, affecting the performance of terminal devices 120 and 130.

[0092] The reason why terminal devices 120 and 130 interfere with each other during channel estimation is that future communication networks may redesign the DMRS in PDSCH for some reason. The redesigned DMRS is located in the same time slot and the same symbol position as the DMRS in 5G PDSCH, but is not orthogonal, which causes terminal devices 120 and 130 to interfere with each other during channel estimation and affects the performance of terminal devices 120 and 130.

[0093] To better understand the embodiments of this application, the following describes MU-MIMO, DMRS in 5G PDSCH, and DMRS in PDSCH of future communication networks. DMRS in 5G PDSCH is abbreviated as 5G DMRS, and DMRS in PDSCH of future communication networks can be abbreviated as DMRS of future communication networks.

[0094] 1. MU-MIMO

[0095] MU-MIMO refers to a network device that can simultaneously serve multiple terminal devices, and both these terminal devices and the network device can use multiple antennas.

[0096] In MU-MIMO scenarios, interference between channels of different terminal devices will be less when they are orthogonal to each other or when the channel correlation is low.

[0097] Currently, demodulation of PDSCH relies on relatively accurate channel estimation, and terminal devices can perform channel estimation based on the DMRS in the PDSCH. To achieve channel estimation in MU-MIMO scenarios, the DMRS configured by the network device for different terminal devices need to be orthogonal; otherwise, interference between DMRSs will increase the error in channel estimation.

[0098] 2. 5G DMRS

[0099] The definitions of DMRS in 3GPP releases (R15 to R17) are as follows:

[0100] The symbols used by DMRS can be divided into: front-loaded DMRS (FL DMRS) and additional DMRS (Add DMRS). Front-loaded DMRS must be configured by default and occupies the first 1-2 symbols of the PDSCH. Additional DMRS supports a maximum of 3 positions, which can be represented as pos1 to pos3. The number of symbols in each additional DMRS position can be the same as the number of symbols in the front-loaded DMRS.

[0101] The front-end DMRS design, placing the DMRS before the transmitted data, helps the system achieve lower processing latency. This design allows the receiver to perform channel estimation earlier. Once the receiver obtains the channel estimate, it can immediately perform correlation demodulation on the buffered received data, regardless of whether the transmission has ended, without needing to receive and buffer all the data before processing.

[0102] To match rapidly changing channel quality and support more accurate demodulation (such as in high-speed rail scenarios), more DMRS symbols or groups have been introduced. Currently, a maximum of 3 additional DMRS groups are supported.

[0103] To meet different deployment scenarios, DMRS can include two different time-domain mapping structures: mapping type A and mapping type B.

[0104] In the DMRS time-domain structure of mapping type A, the first DMRS symbol is located in symbol 2 or symbol 3 within the time slot. This mapping method does not consider the starting position of the actual data transmission, but instead fixes the DMRS at a position relative to the edge of the time slot, after the PDCCH.

[0105] In the DMRS time-domain structure of mapping type B, the first DMRS symbol is fixedly mapped to the first OFDM symbol in the data transmission resource (e.g., PDSCH). In this case, the position of the DMRS is not relative to the start position of the time slot (symbol 0), but rather relative to the start position of the data transmission resource. Mapping type B is mainly used in scenarios where the data transmission PDSCH occupies only a small portion of a time slot, to reduce transmission latency.

[0106] Depending on the maximum number of antenna ports supported by DMRS, 3GPP has specified two configuration types for PDSCH DMRS: Type 1 and Type 2.

[0107] For Type 1, DMRS resource elements (REs) are distributed at 50% density in the frequency domain of a given symbol. If a DMRS occupies one symbol, it can support a maximum of 4 antenna ports. If a DMRS occupies two symbols, it can support a maximum of 8 antenna ports.

[0108] For Type 2, DMRS REs are connected in pairs within a symbol, spaced 4 REs apart. If DMRS occupies one symbol, it can support a maximum of 6 antenna ports. If DMRS occupies two symbols, it can support a maximum of 12 antenna ports.

[0109] For example, taking mapping type A as an example, we introduce a DMRS occupying a single symbol. Figure 2 shows a schematic diagram of a DMRS occupying a single symbol. As shown in Figure 2a, the mapping type of the DMRS is mapping type A, the symbol occupied by the DMRS is symbol 2, and it occupies a single symbol. The configuration type of the DMRS is type 1, and the DMRS REs are distributed at intervals in symbol 2. As shown in Figure 2b, the mapping type of the DMRS is mapping type A, the symbol occupied by the DMRS is symbol 2, and it occupies a single symbol. The configuration type of the DMRS is type 2, and in symbol 2, every two REs are connected together, with a gap of 4 REs between them.

[0110] For Type 1, 1 resource block (RB) = 4 ports = 12 REs, so the pilot density for Type 1 is 12 / 4 = 3 (REs / ports / RBs). For Type 2, 1 RB = 6 ports = 12 REs, so the pilot density for Type 1 is 12 / 6 = 2 (REs / ports / RBs). The pilot density for Type 1 is greater than that for Type 2, therefore, Type 1 has better channel estimation performance than Type 2. In Type 2, non-DMRS REs in the symbols occupied by DMRS can be used to transmit data, thus Type 2 has lower DMRS overhead.

[0111] For example, taking mapping type A as an example, we introduce a DMRS occupying two symbols. Figure 3 shows a schematic diagram of a DMRS occupying two symbols. As shown in Figure 3a, the mapping type of the DMRS is mapping type A, and the symbols occupied by the DMRS include symbols 2 and 3, occupying two symbols. The configuration type of the DMRS is type 1, and the DMRS REs are distributed alternately in symbols 2 and 3. As shown in Figure 3b, the mapping type of the DMRS is mapping type A, and the symbols occupied by the DMRS include symbols 2 and 3, occupying two symbols. The configuration type of the DMRS is type 2, and in symbols 2 and 3, every two REs are connected together, with a gap of 4 REs between them.

[0112] Figures 2 and 3 above describe the design of the front-end DMRS. The design of the supplementary DMRS can be consistent with that of the front-end DMRS. For example, if the configuration type of the front-end DMRS is type 1 and occupies a single symbol, then the configuration type of the supplementary DMRS can also be type 1 and occupy a single symbol.

[0113] Whether additional DMRS exist can be determined by the number of symbols occupied by the PDSCH. The number and location of DMRS can vary depending on the number of symbols occupied by the PDSCH.

[0114] If the configuration type of DMRS is type 1, the relationship between the number and location of DMRS and the number of symbols occupied by PDSCH can be shown in Table 1.

[0115] Table 1

[0116] As shown in Table 1, when the mapping type of the DMRS is mapping type A and the DMRS occupies a single symbol, if the number of symbols occupied by the PDSCH is equal to 2, then no DMRS exists. If the number of symbols occupied by the PDSCH is greater than 2 and less than or equal to 7, a preceding DMRS exists, but no DMRS exists. If the number of symbols occupied by the PDSCH is equal to 8 or 9, then one preceding DMRS and one additional DMRS can exist, with the additional DMRS occupying symbol 7. If the number of symbols occupied by the PDSCH is equal to 11, then one preceding DMRS can exist, and one, two, or three additional DMRSs can exist. If one additional DMRS exists, the symbol occupied by this additional DMRS can be symbol 9; if two additional DMRS exist, the symbols occupied by these two additional DMRS can be symbols 6 and 9 respectively; if three additional DMRS exist, the symbols occupied by these three additional DMRS can be symbols 5, 8, and 11 respectively. Other cases are similar and will not be elaborated here.

[0117] To better understand the number and location of DMRS, the following explanation is provided with reference to Figure 4.

[0118] Figure 4 illustrates the changes in the number and position of DMRS occupying a single symbol when the number of symbols occupied by PDSCH varies. As shown in Figure 4, the mapping type of DMRS is mapping type A, and the DMRS occupies a single symbol.

[0119] When the number of symbols occupied by PDSCH is 7, the first two symbols occupied by PDSCH can be used to transmit PDCCH, symbol 2 occupied by PDSCH can be used to transmit the front-end DMRS, and the other symbols occupied by PDSCH, namely symbols 3 to 6, can be used to transmit PDSCH data.

[0120] When the PDSCH uses 9 symbols, if there are no additional DMRS, the number and position of DMRS are the same as when the PDSCH uses 7 symbols. If there are additional DMRS, then the 7 symbols used by the PDSCH can be used to transmit the additional DMRS.

[0121] When the PDSCH uses 12 symbols, if there are no additional DMRS, the number and position of DMRS are the same as when the PDSCH uses 7 symbols. If there is one additional DMRS, symbol 9 used by the PDSCH can be used to transmit the additional DMRS. If there are two additional DMRS, symbols 6 and 9 used by the PDSCH can be used to transmit the additional DMRS. If there are three additional DMRS, symbols 5, 8, and 11 used by the PDSCH can be used to transmit the additional DMRS.

[0122] When the PDSCH uses 14 symbols, if there are no additional DMRS, the number and position of DMRS are the same as when the PDSCH uses 7 symbols. If there is one additional DMRS, symbol 11 used by the PDSCH can be used to transmit the additional DMRS. If there are two additional DMRS, symbols 7 and 11 used by the PDSCH can be used to transmit the additional DMRS. If there are three additional DMRS, symbols 5, 8, and 11 used by the PDSCH can be used to transmit the additional DMRS.

[0123] If the configuration type of DMRS is type 2, the relationship between the number and location of DMRS and the number of symbols occupied by PDSCH can be shown in Table 2.

[0124] Table 2

[0125] As shown in Table 2, when the DMRS mapping type is mapping type A and the DMRS occupies two symbols, if the number of symbols occupied by the PDSCH is equal to 9, then only the preceding DMRS exists. If the number of symbols occupied by the PDSCH is greater than 9 and less than or equal to 14, then both the preceding DMRS and the additional DMRS can exist. If the number of symbols occupied by the PDSCH is equal to 10, 11, or 12, then one preceding DMRS and one additional DMRS can exist, with the additional DMRS occupying symbols 8 and 9. If the number of symbols occupied by the PDSCH is equal to 13 or 14, then one preceding DMRS and one additional DMRS can exist, with the additional DMRS occupying symbols 10 and 11.

[0126] To better understand the number and location of DMRS, the following explanation is provided in conjunction with Figure 5.

[0127] Figure 5 illustrates the changes in the number and position of DMRS occupying two symbols when the number of symbols occupied by PDSCH varies. As shown in Figure 5, the mapping type of DMRS is mapping type A, and the DMRS occupies two symbols.

[0128] When PDSCH occupies 8 symbols, only the pre-DMRS exists. The first two symbols occupied by PDSCH can be used to transmit PDCCH, symbols 2 and 3 occupied by PDSCH can be used to transmit pre-DMRS, and the remaining symbols occupied by PDSCH can be used to transmit PDSCH data.

[0129] When the PDSCH uses 11 symbols, if there are no additional DMRS, the number and position of DMRS are the same as when the PDSCH uses 8 symbols. If there are additional DMRS, symbols 8 and 9 used by the PDSCH can be used to transmit the additional DMRS.

[0130] When the PDSCH uses 14 symbols, if there are no additional DMRS, the number and position of DMRS are the same as when the PDSCH uses 8 symbols. If there are additional DMRS, symbols 10 and 11 used by the PDSCH can be used to transmit the additional DMRS.

[0131] As described above, when the DMRS configuration type is Type 1, a single symbol can support a maximum of 4 antenna ports, and a dual symbol can support a maximum of 8 antenna ports. When the DMRS configuration type is Type 2, a single symbol can support a maximum of 6 antenna ports, and a dual symbol can support a maximum of 12 antenna ports.

[0132] Multi-antenna ports are achieved by orthogonally multiplexing multiple single-antenna ports across multiple RE resources. Orthogonal multiplexing includes frequency division multiplexing (FDM), time division multiplexing (TDM), and code division multiplexing (CDM). This can be understood as the signals on different antenna ports of the same DMRS resource being mutually orthogonal.

[0133] When the DMRS configuration type is type 1, for a single symbol, there exists a frequency domain orthogonal cover code (FD-OCC 2) of length 2. For a double symbol, in addition to FD-OCC 2, there also exists a time domain orthogonal cover code (TD-OCC 2) of length 2.

[0134] For example, the DMRS configuration type is type 1, with a single symbol having 2 CDM groups and 4 antenna ports. In one RB, the time-frequency distribution of different antenna ports can be shown in Figure 6.

[0135] In Figure 6, a single symbol has two CDM groups, namely CDM#0 and CDM#1. CDM#0 supports antenna port 0 (port 0, p0) and antenna port 1 (port 1, p1). CDM#1 supports antenna port 2 (port 2, p2) and antenna port 3 (port 3, p3). In one RB, the two CDM groups support four antenna ports through FD-OCC 2.

[0136] For example, the DMRS configuration type is type 1, with two CDM groups and eight antenna ports in total for the dual symbols. The time-frequency distribution of different antenna ports in one RB can be shown in Figure 7.

[0137] In Figure 7, a single symbol has two CDM groups, namely CDM#0 and CDM#1. CDM#0 supports p0, p1, antenna port 4 (port 4, p4), and antenna port 5 (port 5, p5). CDM#1 supports p2, p3, antenna port 6 (port 6, p6), and antenna port 7 (port 7, p7). In one RB, the two CDM groups support eight antenna ports through FD-OCC 2 and TD-OCC 2. It should be noted that the viewpoint of TD-OCC 2 is not shown in Figure 7.

[0138] When the DMRS configuration type is type 2, there are 3 CDM groups per symbol, and each CDM group can support 2 antenna ports through FD-OCC 2. The time-frequency distribution of different antenna ports in an RB can be shown in Figure 8.

[0139] In Figure 8, a single symbol has three CDM groups: CDM#0, CDM#1, and CDM#2. CDM#1 supports p0 and p1, and CDM#2 supports p4 and p5. Within an RB, the three CDM groups support six antenna ports via FD-OCC 2.

[0140] When the DMRS configuration type is type 2, there are a total of 3 CDM groups in the dual symbol, and each CDM group can support 4 antenna ports through FD-OCC 2 and TD-OCC 2. The time-frequency distribution of different antenna ports in one RB can be shown in Figure 9.

[0141] In Figure 9, the dual-symbol design has three CDM groups: CDM#0, CDM#1, and CDM#2. CDM#1 supports p0, p1, p6, and p7. CDM#2 supports p2, p3, p8, and p9. CDM#2 supports p4, p5, p10, and p11. Within one RB, the three CDM groups support 12 antenna ports via FD-OCC 2 and TD-OCC 2. It should be noted that the viewing angle of TD-OCC 2 is not shown in Figure 9.

[0142] 3GPP Release 18 enhanced DMRS, primarily by increasing the frequency domain OCC length from 2 to 4, thus doubling the number of supported antenna ports compared to Releases 15 through 17.

[0143] For example, Table 3 shows a comparison of the antenna ports supported by DMRS in different versions.

[0144] Table 3

[0145] As shown in Table 3, when the DMRS configuration type is type 1, the length of the intermediate frequency domain OCC in R15 to R17 is 2, the maximum number of antenna ports supported by a single symbol is 4, and the maximum number of antenna ports supported by a dual symbol is 8; the length of the intermediate frequency domain OCC in R18 is 4, the maximum number of antenna ports supported by a single symbol is 8, and the maximum number of antenna ports supported by a dual symbol is 16.

[0146] When the DMRS configuration type is type 2, the length of the intermediate frequency domain OCC in R15 to R17 is 2, the maximum number of antenna ports supported by a single symbol is 6, and the maximum number of antenna ports supported by a dual symbol is 12; the length of the intermediate frequency domain OCC in R18 is 4, the maximum number of antenna ports supported by a single symbol is 12, and the maximum number of antenna ports supported by a dual symbol is 24.

[0147] For example, Figure 10 shows a schematic diagram comparing the FD-OCC length of DMRS in different versions. As shown in Figure 10, the configuration type of DMRS is type 1. In R15, the FD-OCC length of DMRS is 2, and in R18, the FD-OCC length of DMRS is 4.

[0148] For example, Figure 11 shows another schematic diagram comparing the FD-OCC length of DMRS in different versions. As shown in Figure 11, the configuration type of DMRS is type 1. In R15, the FD-OCC length of DMRS is 2, and in R18, the FD-OCC length of DMRS is 4.

[0149] 3. DMRS in future communication networks

[0150] There may be incompatibility issues between DMRS in future communication networks and 5G DMRS. Incompatibility means that the antenna ports supported by 5G DMRS are not orthogonal to the antenna ports supported by the DMRS in future communication networks.

[0151] The DMRS time-frequency pattern of future communication networks may be redesigned for the following reasons, resulting in a difference between the DMRS design of future communication networks and that of 5G DMRS:

[0152] 1) With the increase in massive multiple-input multiple-output (MM) specifications, future communication networks will need to support a higher number of DMRS ports.

[0153] 2) To improve the capabilities of channel estimation algorithms, it is necessary to reduce DMRS pilot density, reduce DMRS overhead, and increase PDSCH resources.

[0154] The mapping type of the DMRS in future communication networks can also include mapping type A and mapping type B. This application embodiment uses mapping type A as an example to illustrate the time-frequency resources that the DMRS of a future communication network can occupy. The DMRS configuration type of the future communication network can include type 3 and type 4. When the DMRS configuration type of the future communication network is type 3, a single symbol can support 3 CDM groups and a maximum of 12 antenna ports. When the DMRS configuration type of the future communication network is type 4, a single symbol can support 6 CDM groups and a maximum of 12 antenna ports.

[0155] For example, Figure 12 shows a comparison of 5G DMRS and DMRS in future communication networks. Under Release 18, when the 5G DMRS configuration type is Type 1, the available time-frequency resources are as shown in Figure 12(a). It occupies a single symbol, supports 2 CDM groups, supports a maximum of 8 ports, and has a pilot density of 1.5 (RE / port / RB). When the DMRS configuration type of the future communication network is Type 3, the available time-frequency resources are as shown in Figure 12(b). A single symbol can support 3 CDM groups, supports a maximum of 12 antenna ports, and has a pilot density of 1 (RE / port / RB).

[0156] For example, Figure 13 shows a comparison of another 5G DMRS and the DMRS of a future communication network. In Release 18, when the 5G DMRS configuration type is Type 2, the available time-frequency resources are as shown in Figure 13a. It occupies a single symbol, supports 3 CDM groups, supports a maximum of 12 ports, and has a pilot density of 1 (RE / port / RB). When the DMRS configuration type of the future communication network is Type 4, the available time-frequency resources are as shown in Figure 13b. A single symbol can support 6 CDM groups, supports a maximum of 12 antenna ports, and has a pilot density of 1 (RE / port / RB). The DMRS overhead is lower when not all antenna ports are fully utilized.

[0157] Figures 12 and 13 illustrate the concept using a front-end DMRS as an example. The design of the additional DMRS in future communication networks can be the same as that of the additional DMRS in 5G, and will not be elaborated here.

[0158] As can be seen from the above introduction to 5G DMRS and DMRS of future communication networks, when 5G DMRS and DMRS of future communication networks occupy the same symbol position, 5G DMRS and DMRS of future communication networks are not orthogonal.

[0159] Currently, network devices can use rate matching to mitigate the impact of the non-orthogonality between 5G DMRS and future communication networks' DMRS. Rate matching refers to the process of adjusting the transmitted data rate to match physical layer transmission resources (such as time-frequency resource blocks).

[0160] In one example, network devices can configure RB symbol-level rate matching time-frequency format patterns to terminal devices via radio resource control (RRC), and can instruct the RB symbol-level rate matching time-frequency format pattern to take effect via downlink control information (DCI), in order to reduce the impact of 5G DMRS and the non-orthogonality of DMRS in future communication networks through the RB symbol-level rate matching time-frequency format pattern.

[0161] For example, Figure 14 illustrates a schematic diagram of an RB symbol-level rate matching time-frequency format pattern. As shown in Figure 14, the network device can send three bitmaps to the terminal device via RRC. Bitmap 1 may include 275 bits for configuring RB-level rate matching in the frequency domain; bitmap 2 may include 14 bits for configuring OFDM symbol-level rate matching in the time domain; and bitmap 3 may include 20 bits for configuring the time-domain periodic pattern. These three bitmaps are used to determine the RB-level rate matching pattern. The network device can indicate whether the configured RB-level rate matching pattern is effective via DCI. After receiving the DCI, if the DCI indicates that the configured RB-level rate matching pattern is effective, the terminal device will perform the rate matching process using the configured RB-level rate matching pattern.

[0162] In another example, network devices can configure RE-level rate matching time-frequency format patterns to terminal devices via RRC, and can instruct the RE-level rate matching time-frequency format pattern to take effect via DCI, in order to reduce the impact of DMRS non-orthogonality in 5G DMRS and future communication networks through the RE-level rate matching time-frequency format pattern.

[0163] For example, Figure 15 illustrates a schematic diagram of a RE-level rate matching time-frequency format pattern. As shown in Figure 15, different antenna ports can be configured with different RE-level rate matching time-frequency format patterns. Within the same RE-level rate matching time-frequency format pattern, resources filling different patterns can correspond to different reference signals, such as the cell-specific reference signal (CRS) in the LTE protocol and the channel state information reference signal (CSI-RS) in the NR protocol, used to avoid interference with these reference signals. Network devices can indicate the activation of the configured RE-level rate matching time-frequency format pattern via DCI. After receiving the DCI, the terminal device can perform the rate matching process based on the configured RE-level rate matching time-frequency format pattern.

[0164] In this approach, RRC is used to configure the rate-matching time-frequency format pattern, and DCI is used to indicate whether the rate-matching time-frequency format pattern is effective. The configured rate-matching time-frequency format pattern will not be changed until the RRC configures a new one. However, DMRS only exists when PDSCH scheduling is in place, and PDSCH scheduling is dynamic based on demand. If the time-frequency position of PDSCH changes, the time-frequency position of DMRS may also change, requiring a change to the rate-matching time-frequency format pattern. RRC is not suitable for frequent configuration, therefore, there may be situations where the configured rate-matching time-frequency format pattern is not applicable to DMRS, reducing the accuracy of channel estimation.

[0165] In view of this, embodiments of this application provide a method for indicating DMRS. After configuring DMRS to be located at a first symbol position through configuration information, if DMRS of other terminal devices also occupy the first symbol position, the first information indicates that DMRS is located at a second symbol position. In this way, the DMRS of different terminal devices occupy different symbol positions, which helps to reduce the probability of mutual interference and improve the accuracy of channel estimation.

[0166] In the embodiments of this application, the functions of the network device can be executed by modules (such as chips) within the network device, or by a control subsystem that includes network device functions. This control subsystem, including network device functions, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of the terminal can be executed by modules (such as chips or modems) within the terminal, or by a device that includes terminal functions. For ease of description, the methods of the embodiments of this application will be described in detail below using network devices and terminal devices as the execution entities.

[0167] It should be understood that the terminal device can be the terminal device itself, or a chip, chip system, or processor that supports the terminal device in implementing the methods provided in the embodiments of this application, or a logic module or software that can implement all or part of the terminal device; the network device can be the network device itself, or a chip, chip system, or processor that supports the network device in implementing the methods provided in the embodiments of this application, or a logic module or software that can implement all or part of the network device, and this application does not specifically limit it in this regard.

[0168] To better understand the embodiments of this application, the methods provided by the embodiments of this application will be described in detail below with reference to Figures 16 to 18. The embodiments shown in this application illustrate the methods provided by the embodiments of this application from the perspective of device interaction. The specific forms and quantities of the devices shown are merely examples and should not constitute any limitation on the implementation of the methods provided by the embodiments of this application.

[0169] For example, Figure 16 shows a schematic interactive diagram of a DMRS indication method provided in an embodiment of this application. This method can be applied to the communication system shown in Figure 1 above, but the embodiments of this application are not limited thereto. As shown in Figure 16, the method may include the following steps:

[0170] S1601. The network device sends configuration information to the first terminal device. The configuration information is used to determine that the first DMRS is located at the first symbol position.

[0171] In the scenario of Figure 1 above, the first terminal device can be a terminal device using a future communication network or a terminal device using a 5G communication network. This application embodiment does not limit this.

[0172] In some examples, configuration information can be carried in RRC signaling. For instance, RRC signaling configures the first DMRS and indicates the first DMRS parameter "pos2". The terminal device can determine the first symbol position of the first DMRS based on the information configured in the RRC signaling and the symbol length of the PDSCH scheduled by DCI, as described in Tables 1 and 2 above, and will not be repeated here.

[0173] The first DMRS can be used to represent one DMRS or multiple DMRSs, and this application does not limit this. If the first DMRS is used to represent one DMRS, then the first DMRS can be a preceding DMRS or an additional DMRS. If the first DMRS is used to represent multiple DMRSs, then the first DMRS can include a preceding DMRS and an additional DMRS. If the first DMRS is used to represent multiple DMRSs, then the first symbol position can be understood as the symbol position occupied by each of the multiple DMRSs.

[0174] For example, if the first DMRS is used to represent one DMRS, the first DMRS is located at the first symbol position. The first symbol position can be symbol 2 in a time slot, such as the symbol position occupied by the preceding DMRS when the length of the PDSCH is equal to 9 in Figure 4 above. If the first DMRS is used to represent two DMRSs, these two DMRSs can be DMRS1 and DMRS2. The symbol position occupied by DMRS1 can be symbol 2 in a time slot, and the symbol position occupied by DMRS2 can be symbol 7 in a time slot. Then the first DMRS is located at the first symbol position, where the first symbol position can include symbol 2 and symbol 7 in a time slot, such as the symbol positions occupied by the preceding DMRS and the additional DMRS when the length of the PDSCH is equal to 9 in Figure 4 above.

[0175] When the first DMRS is used to represent a DMRS, the first symbol position may include one symbol position or two symbol positions. If the first symbol position includes one symbol position, it means that the first DMRS occupies one symbol, or a single symbol. If the second symbol position includes two symbol positions, it means that the first DMRS occupies two symbols, or a double symbol.

[0176] For example, the first symbol position may include a symbol position as shown in Figure 2 above, where the first symbol position may be symbol 2 in a time slot. Alternatively, the first symbol position may include a symbol position as shown in Figure 3 above, where the first symbol position may be both symbol 2 and symbol 3 in a time slot.

[0177] After the first terminal device establishes a communication connection with the network device, the network device can send configuration information to the first terminal device to facilitate channel estimation based on the first DMRS.

[0178] S1602. The network device sends first information to the first terminal device. The first information is used to determine that the first DMRS is located at the second symbol position. The second symbol position is located in the same time unit as the first symbol position. The second symbol position is used to receive the first DMRS.

[0179] A time unit can also be called a time domain unit, and this application does not limit this. A time unit can be an orthogonal frequency division multiplexing (OFDM) symbol, a slot, a subframe, a frame, or a microslot, etc., and this application does not limit this.

[0180] The second symbol position is located in the same time unit as the first symbol position. For example, the time unit is a time slot, and a time slot includes 14 symbols, which include symbols 0 to 13. The first symbol position can be symbol 2, and the second symbol position can be symbol 3.

[0181] The first information is used to determine that the first DMRS is located at the second symbol position. This can be understood as indicating that the symbol position of the first DMRS should be switched from the first symbol position to the second symbol position. In some examples, the first information can be carried in DCI signaling. For instance, DCI used for scheduling PDSCHs indicates that the first DMRS in the scheduled PDSCH is located at the second symbol position.

[0182] A network device may send the first information when: a second terminal device is connected to the network, and the DMRS configured by the network device for the second terminal device is also located at the first symbol position. To reduce mutual interference between different terminal devices, the network device may send the first information to the first terminal device.

[0183] For example, Figure 17 illustrates a schematic diagram of a symbol position change. As shown in Figure 17, the first DMRS occupies a single symbol, and the symbol position of the first DMRS is symbol 2. The symbol position of the DMRS of the second terminal device is also symbol 2. The first terminal device receives the first information and determines that the symbol position of the first DMRS is symbol 3.

[0184] Optionally, when the second terminal device disconnects from the network device, the network device can send second information to the first terminal device. The second information is used to determine that the first DMRS is located at the first symbol position. That is, in the absence of interference from the second terminal device, the first terminal device can receive the first DMRS at the first symbol position.

[0185] S1603. Based on the first information, the first terminal device can receive the first DMRS at the second symbol position.

[0186] The DMRS indication method provided in this application embodiment can determine to receive the first DMRS at the second symbol position based on the first information, instead of receiving the first DMRS at the first symbol position, which helps to reduce the impact on other terminal devices and improve the accuracy of channel estimation.

[0187] In the method shown in Figure 16 above, the symbol position of the first DMRS is switched from a first symbol position to a second symbol position. In some examples, the first symbol position and the second symbol position may satisfy one or more of the following: the first symbol position is adjacent to the second symbol position; the first symbol position is after the second symbol position; the first symbol position is before the second symbol position; or, the first symbol position and the second symbol position are separated by one symbol.

[0188] In one possible implementation, the first symbol position is adjacent to the second symbol position, and the first symbol position precedes the second symbol position. For example, in the example shown in Figure 17 above, the first DMRS occupies a single symbol, the first symbol position is symbol 2 in a time slot, and the second symbol position is symbol 3 in a time slot. Alternatively, if the first DMRS occupies two symbols, and the first symbol position includes symbols 2 and 3 in a time slot, then the second symbol position may include symbols 4 and 5 in a time slot.

[0189] In another possible implementation, the first symbol position is separated from the second symbol position by one symbol, and the first symbol position precedes the second symbol position. For example, if the first DMRS occupies a single symbol, and the first symbol position is symbol 2 in a time slot, the second symbol position can be symbol 4 in a time slot. Alternatively, the first DMRS occupies two symbols, and if the first symbol position is symbols 2 and 3 in a time slot, the second symbol position can be symbols 5 and 6 in a time slot.

[0190] In another possible implementation, the first symbol position is adjacent to the second symbol position, and the first symbol position follows the second symbol position. For example, the first DMRS occupies a single symbol, the first symbol position is symbol 2 in a time slot, and the second symbol position is symbol 1 in a time slot. Alternatively, if the first DMRS occupies two symbols, and the first symbol position includes symbols 5 and 6 in a time slot, then the second symbol position can include symbols 3 and 4 in a time slot.

[0191] Whether the first symbol position and the second symbol position are adjacent or separated by one symbol can be predefined by the protocol, or can be indicated by the network device. This application embodiment does not limit this.

[0192] Whether the position of the first symbol is before or after the position of the second symbol can be predefined by the protocol, or it can be indicated by the network device. This application embodiment does not limit this.

[0193] If indicated by a network device, the indication information can be carried in RRC or DCI signaling.

[0194] For example, a network device sends an RRC signaling message to a first terminal device. The RRC signaling message is used to instruct the first DMRS to shift backward, or to instruct the first DMRS to shift forward. Based on the RRC signaling message, the first terminal device can determine that the second symbol position is after the first symbol position, or before the first symbol position.

[0195] For example, a network device sends DCI signaling to a first terminal device. The DCI signaling is used to instruct the first DMRS to shift backward, or to instruct the first DMRS to shift forward. Based on the DCI signaling, the first terminal device can determine whether the second symbol position is after the first symbol position, or before the first symbol position.

[0196] As described above, the first DMRS can include a pre-set DMRS and an additional DMRS. The symbol positions of both the pre-set and additional DMRS can be shifted, or some DMRS can be shifted while others remain unchanged. Which specific DMRS need to be shifted can be determined through protocol predefinition or by indication from the network device.

[0197] In some examples, the DMRS that needs to be shifted is predefined by the protocol. For instance, the protocol can define that if the preceding DMRS is shifted, the appended DMRS is also shifted. Alternatively, the protocol can define that the appended DMRS can be shifted by the same number of symbols in the direction of the preceding DMRS shift.

[0198] In other examples, the network device indicates whether the DMRS needs to be shifted. For instance, the network device sends DCI signaling to the first terminal device, indicating whether the preceding DMRS and the supplementary DMRS need to be shifted. Alternatively, the network device sends RRC and DCI signaling to the first terminal device, with the RRC signaling indicating whether the preceding DMRS and the DCI signaling indicating whether the supplementary DMRS need to be shifted.

[0199] In the method shown in Figure 16 above, the first information is used to determine that the first DMRS is located at the second symbol position. The specific information indicated by the first information can have various possible implementations.

[0200] In one possible implementation, the first DMRS is used for data demodulation of the first PDSCH of the first terminal device, the first information indicates that the second PDSCH of the second terminal device is spatially multiplexed with the first PDSCH, the first terminal device uses a first RAT, and the second terminal device uses a second RAT.

[0201] The first terminal device uses a first RAT, which can also be referred to as the first terminal device using a first communication network or a first communication standard. The second terminal device uses a second RAT, which can also be referred to as the second terminal device using a second communication network or a second communication standard. This application does not limit this aspect in the embodiments.

[0202] For example, the first terminal device uses the 5G communication standard, and the second terminal device uses a future communication standard. Or, the first terminal device uses a future communication standard, and the second terminal device uses the 5G communication standard.

[0203] If the first information indicates that the second PDSCH of the second terminal device is spatially multiplexed with the first PDSCH, it suggests that interference may exist between the first and second terminal devices. The first terminal device can determine that the first DMRS has shifted and can determine the location of the first DMRS at the second symbol position according to a preset rule. The preset rule can be: regardless of whether the first DMRS is a preceding DMRS or an additional DMRS, the symbol position of the first DMRS is shifted backward by x symbols, where x equals the number of symbols occupied by the first DMRS. If the first DMRS occupies a single symbol, then x = 1; if the first DMRS occupies two symbols, then x = 2.

[0204] In some examples, the first information can be carried in the DCI. The DCI may include a bit that can be used to indicate whether the second PDSCH of the second terminal device is spatially multiplexed with the first PDSCH. For example, a value of 1 indicates that the second PDSCH of the second terminal device is spatially multiplexed with the first PDSCH. A value of 0 indicates that the second PDSCH of the second terminal device is not spatially multiplexed with the first PDSCH.

[0205] In this implementation, the first terminal device can detect that a second terminal device occupies the same symbol position as the first terminal device. In order to reduce interference, the first terminal device can determine a new symbol position (i.e., the second symbol position).

[0206] In another possible implementation, the first information indicates that the first DMRS needs to be shifted, and the terminal device can determine the location of the first DMRS at the second symbol position according to a preset rule. The preset rule can be found in the example above and will not be repeated here.

[0207] For example, the first information can be carried in the DCI. The DCI may include a bit that can be used to indicate that the first DMRS needs to be shifted. For example, the bit value of 1 indicates that the first DMRS needs to be shifted. The bit value of 0 indicates that the first DMRS does not need to be shifted.

[0208] For example, the first DMRS includes n DMRSs. The first information can be carried in the DCI, which can include n bits, each corresponding to one of the n DMRSs. Each of the n bits is used to indicate whether the corresponding DMRS needs to be shifted. For example, the first DMRS includes 4 DMRSs, which can include a pre-set DMRS, a first additional DMRS, a second additional DMRS, and a third additional DMRS. The bit value of these 4 bits can be 1010, which can be used to indicate that the pre-set DMRS and the second additional DMRS need to be shifted, while the first additional DMRS and the third additional DMRS do not need to be shifted, or it can be used to indicate that the pre-set DMRS and the second additional DMRS do not need to be shifted, while the first additional DMRS and the third additional DMRS need to be shifted.

[0209] For example, the configuration information indicates multiple symbol positions through an N-bit bitmap. These multiple symbol positions may include a first symbol position, and the first information is used to indicate whether the multiple symbol positions need to be avoided. Specifically, when a bit in the N bits is 1, it can be used for one symbol position. If two consecutive bits in the N bits are 1, then these two bits can jointly represent one symbol position. Here, N can be the number of symbols included in the time unit.

[0210] For example, a time unit can be a time slot, and a time slot can include 14 symbols. The configuration information can then indicate a 14-bit bitmap. When the 14-bit bitmap is 001000000000000, there is a symbol position on the symbol at symbol index 2. This symbol position can be the first symbol position of the first DMRS, or it can overlap with the first symbol position of the first DMRS. The first information can include a bit indicating whether the symbol position determined by N bits needs to be avoided. When the 14-bit bitmap is 001100000000000, there is a symbol position on the symbols at symbol index 2 and symbol index 3. This symbol position can be the first symbol position of the first DMRS, or it can overlap with the first symbol position of the first DMRS. The first information can include a bit indicating whether the symbol position determined by N bits needs to be avoided. If the bit indicates that the symbol position determined by N bits needs to be avoided, and the first symbol position of the first DMRS overlaps with the symbol position determined by N bits, then the first DMRS switches from the first symbol position to the second symbol position to avoid the symbol position determined by N bits.

[0211] In this implementation, the first terminal device receives the avoidance instruction and re-determines the symbol position, which helps to save signaling overhead.

[0212] In another possible implementation, the first information indicates the offset of the second symbol position relative to the first symbol position. The first terminal device can determine the second symbol position based on the offset of the first symbol position and the second symbol position relative to the first symbol position.

[0213] In this implementation, the first terminal device receives the offset of the second symbol position relative to the first symbol position, and determines the position of the second symbol based on the offset, which is simple to implement.

[0214] In another possible implementation, the first information indicates a bit map of P bits, and the second symbol position is the symbol position corresponding to the bit with the first value among the P bits, where P is the number of symbols included in the time unit.

[0215] In a bitmap of P bits, one bit corresponds to a symbol in a time unit. When the value of a bit in these P bits is the first value, it means that the symbol corresponding to that bit is the shifted symbol position, i.e., the second symbol position.

[0216] For example, a time unit can be a time slot, and a time slot can include 14 symbols. The first information can then indicate a 14-bit bitmap. This 14-bit bitmap can be 00010000000000. If the first value is 1, then the symbol position corresponding to the bit with a value of 1 in the 14 bits of the second position is symbol 3, and symbol 3 can be the second symbol position. It is understood that in this example, the first DMRS occupies a single symbol. Alternatively, the 14-bit bitmap can be 00001100000000. If the first value is 1, then the symbol positions corresponding to the bit with a value of 1 in the 14 bits of the second position are symbols 4 and 5, and symbols 4 and 5 can be the second symbol positions. It is understood that in this example, the first DMRS occupies two symbols.

[0217] In this way, the position of the second symbol can be determined by a bitmap of P bits, which simplifies the parsing process and helps reduce the error rate of parsing.

[0218] As can be seen from the above embodiments, when the symbol position of the first DMRS is switched from the first symbol position to the second symbol position, the first symbol position can be occupied by other information. This application provides a variety of methods.

[0219] In one implementation, the first DMRS is used for data demodulation of the first PDSCH. The frequency domain resources at the first symbol position are unavailable to the first PDSCH. That is, the first PDSCH cannot occupy the frequency domain resources at the first symbol position, or the frequency domain resources at the first symbol position cannot be occupied by the first PDSCH, or the frequency domain resources at the first symbol position are not used for the first PDSCH, or the resources occupied by the first PDSCH do not include the frequency domain resources at the first symbol position, or the network device will not allocate the frequency domain resources at the first symbol position to the first PDSCH.

[0220] In this way, the first symbol position is occupied by other terminal devices, and the first PDSCH does not occupy the frequency domain resources of the first symbol position. This is equivalent to rate matching of the first symbol position, which helps to reduce interference to other terminal devices.

[0221] In another implementation, the first DMRS is used for data demodulation of the first PDSCH, and the configuration information is also used to determine the third symbol position, which overlaps with the first symbol position in the time domain. If the third symbol position is not available for the first PDSCH, then the second symbol position does not overlap with the third symbol position in the time domain.

[0222] The overlap of the third symbol position with the first symbol position in the time domain can indicate partial or complete overlap. This overlap suggests that the overlapping time-domain resource has two uses: one corresponding to the first symbol position and the other to the third symbol position. If the third symbol position is unavailable for the first PDSCH, it indicates potential interference due to the two uses of the overlapping time-domain resource. In this case, the first DMRS can occupy the second symbol position, which does not overlap with the third symbol position in the time domain. This allows the overlapping time-domain resource to have only the use of the third symbol position, while the time-domain resource at the second symbol position can have the use of the first symbol position, thus reducing interference.

[0223] In some examples, the first information may indicate whether the frequency domain resources at the third symbol position are available for the first PDSCH. If the first information indicates that the frequency domain resources at the third symbol position are not available for the first PDSCH, then the first DMRS of the first PDSCH is located at the second symbol position, and the frequency domain resources at the third symbol position are not used for the first PDSCH.

[0224] In other examples, some frequency domain resources at the third symbol position are unavailable to the first PDSCH. For instance, there are non-overlapping and overlapping frequency domain resources at the third symbol position and the first symbol position; the non-overlapping frequency domain resources are available to the first PDSCH, while the overlapping frequency domain resources are unavailable to the first PDSCH.

[0225] For example, Figure 18 illustrates a schematic diagram of the occupancy of frequency domain resources at a first symbol position. As shown in Figure 18, the first and third symbol positions completely overlap in the time domain, while the second and first symbol positions do not overlap in the time domain. Part of the frequency domain resources at the third symbol position are available for the first PDSCH, while another part is unavailable for the first PDSCH. Specifically, the frequency domain resources available for the first PDSCH can be those where the third symbol position does not overlap with the first symbol position, and the frequency domain resources unavailable for the first PDSCH can be those where the third symbol position overlaps with the first symbol position.

[0226] In this way, some frequency domain resources are unavailable to the first PDSCH, which helps reduce interference, while other frequency domain resources are available to the first PDSCH, which helps increase the available resources of the PDSCH.

[0227] Optionally, the third symbol position can be the symbol position of the second DMRS. The second DMRS is used for data demodulation of the second PDSCH of the second terminal device, and the first DMRS is used for data demodulation of the first PDSCH of the first terminal device. The first terminal device uses the first RAT, and the second terminal device uses the second RAT.

[0228] The second DMRS can occupy all or part of the frequency domain resources of the third symbol position. The second symbol position and the third symbol position do not overlap in the time domain. In this way, the first terminal device and the second terminal device do not occupy the same time domain resources, which helps to reduce the probability of interference.

[0229] In the above embodiments, some frequency domain resources may be unavailable to the first PDSCH. The method for determining the unavailable frequency domain resources is described below.

[0230] In one possible implementation, the network device may send information to the first terminal device indicating at least one code division multiplexing (CDM) group and the type of at least one CDM group; the first terminal device may determine some unavailable frequency domain resources based on the type of at least one CDM group and at least one CDM group.

[0231] The third symbol location may include multiple CDM groups, and a portion of the frequency domain resources of the third symbol location may occupy one or more of these CDM groups. The number of CDM groups included in the third symbol location may vary depending on the type. Therefore, the network device may send information to the first terminal device indicating at least one code division multiplexing (CDM) group and the type of at least one CDM group to determine the portion of the frequency domain resources occupied by the third symbol location, or in other words, to determine the resources unavailable to the first PDSCH.

[0232] For example, in the example shown in Figure 6 above, the CDM group type is type 1. One symbol position can include two CDM groups, namely CDM#0 and CDM#1. If some frequency domain resources of the third symbol position occupy CDM#0, the network device can send CDM#0 and type 1 to the first terminal device. The first terminal device can determine the unavailable resources based on CDM#0 and type 1. CDM#0 can also be represented as {CDM group 0}, which is not limited in this embodiment.

[0233] If the frequency domain resources at the third symbol position occupy CDM#0 and CDM#1, the network device can send CDM#0, CDM#1, and type 1 to the first terminal device. The first terminal device can determine some unavailable resources based on CDM#0, CDM#1, and type 1. CDM#0 and CDM#1 can also be represented as {CDM group 0, CDM group 1}, and this embodiment does not limit this representation.

[0234] For example, in the example shown in Figure 8 above, the CDM group type is type 2. A symbol position can include three CDM groups, namely CDM#0, CDM#1, and CDM#2. If the frequency domain resources of the third symbol position occupy CDM#0 and CDM#1, the network device can send CDM#0, CDM#1, and type 2 to the first terminal device. The first terminal device can determine some unavailable resources based on CDM#0, CDM#1, and type 2. CDM#0 and CDM#1 can also be represented as {CDM group 0, CDM group 1}, and this embodiment does not limit this representation.

[0235] It is understandable that after a network device determines that some resources are unavailable, it can send PDSCH in other available resource areas, which helps to improve the availability of PDSCH resources.

[0236] In another possible implementation, the network device can send a pattern of frequency domain resources at the third symbol position to the first terminal device, marking which resources are occupied and which are not. Based on this pattern, the first terminal device can determine the resources that are unavailable in the first PDSCH.

[0237] For example, the network device can send the pattern shown in FIG6 above to the first terminal device, where the frequency domain resources filled with black can be the frequency domain resources occupied by the third symbol position. Based on this pattern, the terminal device can determine the resources that are unavailable in the first PDSCH.

[0238] As can be seen from the above embodiments, there are two ways to determine whether the frequency domain resources at the first symbol position are available to the first PDSCH. One way is that the frequency domain resources at the first symbol position are not available to the first PDSCH. The other way is that some of the frequency domain resources at the first symbol position are not available to the first PDSCH. The situation where the frequency domain resources at the first symbol position are not available to the first PDSCH can be called RB-level rate matching. The situation where some of the frequency domain resources at the first symbol position are not available to the first PDSCH can be called RE-level rate matching. The specific rate matching method used can be predefined by the protocol or determined by the network device.

[0239] If predefined by the protocol, it can specify whether to use RB-level rate matching or RE-level rate matching.

[0240] If determined by the network device, the network device can determine the appropriate rate matching method based on the capabilities of the terminal device. For example, the terminal device can report capability information to the network device. If the capability information indicates support for RB-level rate matching, the network device can determine that the frequency domain resources at the first symbol position are unavailable for the first PDSCH, i.e., it will not configure the frequency domain resources at the first symbol position for the first PDSCH. If the capability information indicates support for RE-level rate matching, the network device can determine that some frequency domain resources at the first symbol position are unavailable for the first PDSCH, i.e., it will not configure some frequency domain resources at the first symbol position for the first PDSCH.

[0241] It is understood that the various numerical designations used in the embodiments of this application are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The order of the process numbers described above does not imply the order of execution; the execution order of each process should be determined by its function and internal logic.

[0242] In the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terminology and / or descriptions of different embodiments are consistent and can be referenced by each other. The technical features of different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0243] It is understood that, in order to achieve the functions in the above embodiments, the terminal device or network device includes hardware structures and / or software modules corresponding to perform each function. Those skilled in the art should readily recognize that, based on the units and method steps of the various examples described in conjunction with the embodiments disclosed in this application, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed by hardware or by computer software driving hardware depends on the specific application scenario and design constraints of the technical solution.

[0244] Figures 19 and 20 are schematic diagrams of possible communication devices provided in embodiments of this application. These communication devices can be used to implement the functions of the first terminal device or network device in the above method embodiments, and thus can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device can be the terminal 130 shown in Figure 1, the network device 110 shown in Figure 1, or a module (such as a chip) applied to the terminal 130 or the network device 110.

[0245] As shown in Figure 19, the communication device 1900 includes a processing unit 1910 and a transceiver unit 1920. The communication device 1900 is used to implement the functions of the terminal device or network device in the method embodiment shown in Figure 16 above.

[0246] In one possible implementation, the device 1900 is used to perform the steps corresponding to the first terminal device in the above method.

[0247] The transceiver unit 1920 is used to receive configuration information, which is used to determine that the first demodulation reference signal DMRS is located at the first symbol position; and to receive first information, which is used to determine that the first DMRS is located at the second symbol position, and the second symbol position is located in the same time unit as the first symbol position; the processing unit 1910 is used to determine that the first DMRS is received at the second symbol position.

[0248] Optionally, the first symbol position and the second symbol position satisfy one or more of the following: the first symbol position and the second symbol position are adjacent; or, the first symbol position is after the second symbol position; or, the first symbol position is before the second symbol position; or, the first symbol position and the second symbol position are separated by one symbol.

[0249] Optionally, the first DMRS is used for data demodulation of the first physical downlink data channel (PDSCH) of the first terminal device, the first information indicates that the second PDSCH of the second terminal device is spatially multiplexed with the first PDSCH, the first terminal device uses the first RAT, and the second terminal device uses the second RAT.

[0250] Optionally, the first information indicates the offset of the second symbol position relative to the first symbol position.

[0251] Optionally, the first information indicates a bitmap of P bits, and the second symbol position is the symbol position corresponding to the bit with the first value among the P bits, where P is the number of symbols included in the time unit.

[0252] Optionally, the first DMRS is used for data demodulation of the first PDSCH, and the frequency domain resources at the first symbol position are not available to the first PDSCH.

[0253] Optionally, the first DMRS is used for data demodulation of the first PDSCH, and the configuration information is also used to determine the third symbol position, which overlaps with the first symbol position in the time domain. If the third symbol position is not available for the first PDSCH, then the second symbol position does not overlap with the third symbol position in the time domain.

[0254] Optionally, the third symbol position and the first symbol position have non-overlapping frequency domain resources and overlapping frequency domain resources. The non-overlapping frequency domain resources are available to the first PDSCH, while the overlapping frequency domain resources are not available to the first PDSCH.

[0255] Optionally, the transceiver unit 1920 is further configured to: receive information indicating at least one code division multiplexing (CDM) group and the type of at least one CDM group; the processing unit 1910 is further configured to: determine overlapping frequency domain resources based on the type of at least one CDM group and at least one CDM group.

[0256] Optionally, the third symbol position is the symbol position of the second DMRS. The second DMRS is used for data demodulation of the second PDSCH of the second terminal device, and the first DMRS is used for data demodulation of the first PDSCH of the first terminal device. The first terminal device uses the first RAT, and the second terminal device uses the second RAT.

[0257] Optionally, the first DMRS includes a pre-DMRS and / or an additional DMRS.

[0258] In another possible implementation, the apparatus 1900 is used to perform the steps corresponding to the network device in the above method.

[0259] The processing unit 1910 is used to determine configuration information and first information; the transceiver unit 1920 is used to send configuration information, which is used to determine that the first demodulation reference signal DMRS is located at the first symbol position; and to send first information, which is used to determine that the first DMRS is located at the second symbol position, the second symbol position and the first symbol position are located in the same time unit, and the second symbol position is used to receive the first DMRS.

[0260] Optionally, the transceiver unit 1920 is further configured to: transmit information indicating at least one code division multiplexing (CDM) group and the type of at least one CDM group, and the processing unit 1910 is further configured to: use the type of at least one CDM group and the type of at least one CDM group to determine overlapping frequency domain resources.

[0261] The relationship between the second symbol position and the first symbol position, the specific information indicated by the first information, and the characteristics of the frequency domain resources of the first symbol position can all be referred to the above, and will not be repeated here.

[0262] It should be understood that the communication device 1900 here is embodied in the form of a functional unit. The term "unit" here can refer to an application-specific integrated circuit (ASIC), electronic circuitry, a processor (e.g., a shared processor, a proprietary processor, or a group processor, etc.) and memory for executing one or more software or firmware programs, combined logic circuitry, and / or other suitable components supporting the described functions. In an alternative example, those skilled in the art will understand that the communication device 1900 can be specifically the first terminal device or network device in the above embodiments. The communication device 1900 can be used to execute the various processes and / or steps corresponding to the first terminal device or network device in the above method embodiments; to avoid repetition, these will not be described again here.

[0263] The aforementioned communication device 1900 has the function of implementing the corresponding steps performed by the first terminal device or network device in the above method; the above functions can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above functions. In an embodiment of this application, the communication device 1900 in FIG19 can also be a chip, such as a System-on-a-Chip (SoC).

[0264] As shown in Figure 20, the transmission device 2000 may include a processor 2010, a transceiver 2020, and a memory 2030. The processor 2010, transceiver 2020, and memory 2030 communicate with each other via an internal connection. The memory 2030 stores instructions, and the processor 2010 executes the instructions stored in the memory 2030 to control the transceiver 2020 to transmit and / or receive signals.

[0265] It should be understood that the communication device 2000 may specifically be the terminal device in the above embodiments, and may be used to execute the various steps and / or processes corresponding to the terminal device in the above method embodiments. Optionally, the memory 2030 may include read-only memory and random access memory, and provide instructions and data to the processor. A portion of the memory may also include non-volatile random access memory. For example, the memory may also store device type information. The processor 2010 may be used to execute instructions stored in the memory, and when the processor 2010 executes instructions stored in the memory, the processor 2010 is used to execute the various steps and / or processes of the above method embodiments. The transceiver 2020 may include a transmitter, a receiver, and an antenna. The transmitter may be used to implement the various steps and / or processes corresponding to the transceiver for performing the transmission action. For example, the transmitter may be used to send information to another device via the antenna. The receiver may be used to implement the various steps and / or processes corresponding to the transceiver for performing the reception action. For example, the receiver may be used to receive information from another device via the antenna.

[0266] It should be understood that, in the embodiments of this application, the processor may be a central processing unit (CPU), or it may be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or any conventional processor.

[0267] In implementation, each step of the above method can be completed by integrated logic circuits in the processor's hardware or by instructions in software. The steps of the method disclosed in the embodiments of this application can be directly manifested as execution by a hardware processor, or as a combination of hardware and software modules within the processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. This storage medium is located in memory, and the processor executes the instructions in the memory, combining them with its hardware to complete the steps of the above method. To avoid repetition, detailed descriptions are omitted here.

[0268] This application also provides a processor that can be used to execute the method executed by the first terminal device or network device described above.

[0269] For example, Figure 21 shows a schematic block diagram of a processor. As shown in Figure 21, the processor may include communication circuitry and processing circuitry. The communication circuitry may include one or more hardware components that provide a physical structure that performs various processes related to wireless communication (e.g., signal reception and / or signal transmission). The communication circuitry may include two or more transmit / receive chains. The functions implemented by the communication circuitry may also be processed on a computer-readable medium. The processing circuitry may make judgments and processes based on information received by the communication circuitry. For example, if the communication circuitry receives the configuration information and first information shown in the above embodiments, the processing circuitry may determine, based on the configuration information and the first information, that the first DMRS is received at the second symbol position. If the communication circuitry receives the configuration information shown in the above embodiments but does not receive the first information, the processing circuitry may determine, based on the configuration information, that the first DMRS is received at the first symbol position.

[0270] This application also provides a chip system for a terminal device. This chip system can execute the various processes and / or steps corresponding to the first terminal device in the above method embodiments; to avoid repetition, these will not be described again here.

[0271] For example, Figure 22 illustrates a schematic diagram of a chip system for a terminal device. As shown in Figure 22, this terminal device-side chip system can be implemented using a processing system including one or more processors. The processors may include microprocessors (e.g., x86, ARM), microcontrollers, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), GPUs, programmable logic devices (PLDs), state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to various functions. The aforementioned chip system can be a system-on-a-chip (SoC) system for the terminal device, wherein the processors used can be used to implement the processes described below and any one or more of those processes.

[0272] The processing system may optionally be implemented using a bus architecture, typically represented by a bus. The bus can include any number of interconnect buses and bridges, depending on the specific application and overall design constraints of the processing system. The bus communicatively couples various circuits together, including one or more processors (typically represented by a processor), memory, and computer-readable media (typically represented by a computer-readable media). The bus can also link various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further. The bus interface provides the interface between the transceivers of the bus and terminal devices, as well as between the bus and the interface.

[0273] Optionally, the chip system may also include a transceiver that provides a communication interface or means for communicating with various other devices via a wireless transmission medium. The transceiver may be an input / output interface and may be coupled to an antenna array, and the transceiver and antenna array may be used together for communication with a corresponding network type. At least one interface (e.g., a network interface and / or a user interface) provides a communication interface or means for communication via an internal bus or via an external transmission medium.

[0274] The processor is responsible for managing the bus and general processing, including executing software stored on a computer-readable medium. When the processor executes the software, the software causes the processing system to perform the various functions described below for any particular device.

[0275] The functions that can be implemented by the processor, memory, and computer-readable medium include: encoding, decoding, rate matching, rate dematching, scrambling, descrambling, modulation, demodulation, layer mapping, fast fourier transform (FFT), inverse fast fourier transform (IFFT), inverse discrete fourier transform (IDFT), precoding, RE mapping, channel equalization, deRE mapping, digital beamforming (BF), adding cyclic prefix (CP), removing CP, etc.

[0276] Furthermore, the method provided in the embodiments of this application described above can be applied to O-RAN systems. In an O-RAN system, the O-RAN device can perform the steps performed by the network device described above.

[0277] The network device in this embodiment can also be referred to as an access network device. The access network device (i.e., RAN, such as an eNB, gNB, or next-generation access network device) can communicate with the core network (CN) device through a backhaul link, or it can communicate with the terminal device through an air interface.

[0278] For example, Figure 23 shows a schematic diagram of an access network device. As shown in Figure 23, the access network device includes a BBU and a radio unit (RU), which can communicate via a fronthaul link. The BBU may include at least one central unit (CU) and at least one distributed unit (DU), which can communicate via a midhaul link.

[0279] The BBU in the access network equipment can communicate with the CN equipment via the backhaul link. The RU in the access network equipment can communicate with at least one terminal device via the air interface. The BBU can communicate with at least one RU via the fronthaul link. The BBU and RU can be co-located or not.

[0280] In this embodiment of the application, the CU can determine the configuration information and the first information, and the DU can send the configuration information and the first information to the terminal device through the RU.

[0281] This application also provides a computer-readable storage medium for storing a computer program for implementing the methods shown in the above-described method embodiments.

[0282] This application also provides a computer program product, which includes a computer program (also referred to as code or instructions) that, when run on a computer, allows the computer to perform the methods shown in the above-described method embodiments.

[0283] Those skilled in the art will recognize that the modules and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0284] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and modules described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0285] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or modules may be electrical, mechanical, or other forms.

[0286] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0287] In addition, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module.

[0288] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0289] The above description is merely a specific embodiment of this application, but the protection scope of the embodiments of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the embodiments of this application should be included within the protection scope of the embodiments of this application. Therefore, the protection scope of the embodiments of this application should be determined by the protection scope of the claims.

Claims

1. A method for indicating DMRS, characterized in that, include: Receive configuration information, the configuration information being used to determine that the first demodulation reference signal DMRS is located at the first symbol position; Receive first information, the first information being used to determine that the first DMRS is located at a second symbol position, the second symbol position being located in the same time unit as the first symbol position, the second symbol position being used to receive the first DMRS.

2. The method according to claim 1, characterized in that, The first symbol position and the second symbol position satisfy one or more of the following: The first symbol position is adjacent to the second symbol position; or, The first symbol position is located after the second symbol position; or, The first symbol position is located before the second symbol position; or, There is a one-symbol interval between the first symbol position and the second symbol position.

3. The method according to claim 1 or 2, characterized in that, The first DMRS is used for data demodulation of the first physical downlink data channel (PDSCH) of the first terminal device. The first information indicates that the second PDSCH of the second terminal device is spatially multiplexed with the first PDSCH. The first terminal device adopts the first radio access technology (RAT), and the second terminal device adopts the second RAT.

4. The method according to claim 1 or 2, characterized in that, The first information indicates the offset of the second symbol position relative to the first symbol position.

5. The method according to claim 1 or 2, characterized in that, The first information indicates a bitmap of P bits, and the second symbol position is the symbol position corresponding to the bit with a first value among the P bits, where P is the number of symbols included in the time unit.

6. The method according to any one of claims 1 to 5, characterized in that, The first DMRS is used for data demodulation of the first PDSCH, and the frequency domain resources at the first symbol location are unavailable for the first PDSCH.

7. The method according to any one of claims 1 to 5, characterized in that, The first DMRS is used for data demodulation of the first PDSCH. The configuration information is also used to determine the position of the third symbol. The position of the third symbol overlaps with the position of the first symbol in the time domain. If the position of the third symbol is not available for the first PDSCH, the position of the second symbol does not overlap with the position of the third symbol in the time domain.

8. The method according to claim 7, characterized in that, The third symbol position has non-overlapping frequency domain resources and overlapping frequency domain resources with the first symbol position. The non-overlapping frequency domain resources are available to the first PDSCH, while the overlapping frequency domain resources are not available to the first PDSCH.

9. The method according to claim 8, characterized in that, The method further includes: Receive information indicating at least one Code Division Multiplexing (CDM) group and the type of the at least one CDM group; The overlapping frequency domain resources are determined based on the at least one Code Division Multiplexing (CDM) group and the type of the at least one CDM group.

10. The method according to claim 8 or 9, characterized in that, The third symbol position is the symbol position of the second DMRS. The second DMRS is used for data demodulation of the second PDSCH of the second terminal device, and the first DMRS is used for data demodulation of the first PDSCH of the first terminal device. The first terminal device uses the first RAT, and the second terminal device uses the second RAT.

11. The method according to any one of claims 1 to 10, characterized in that, The first DMRS includes a pre-DMRS and / or an additional DMRS.

12. A method for indicating DMRS, characterized in that, include: Send configuration information, which is used to determine that the first demodulation reference signal DMRS is located at the first symbol position; Send first information, the first information being used to determine that the first DMRS is located at a second symbol position, the second symbol position being located in the same time unit as the first symbol position, the second symbol position being used to receive the first DMRS.

13. The method according to claim 12, characterized in that, The first symbol position and the second symbol position satisfy one or more of the following: The first symbol position is adjacent to the second symbol position; or, the first symbol position is after the second symbol position; or... The first symbol position is located before the second symbol position; or, There is a one-symbol interval between the first symbol position and the second symbol position.

14. The method according to claim 12 or 13, characterized in that, The first DMRS is used for data demodulation of the first physical downlink data channel (PDSCH) of the first terminal device. The first information indicates that the second PDSCH of the second terminal device is spatially multiplexed with the first PDSCH. The first terminal device adopts the first radio access technology (RAT), and the second terminal device adopts the second RAT.

15. The method according to claim 12 or 13, characterized in that, The first information indicates the offset of the second symbol position relative to the first symbol position.

16. The method according to claim 12 or 13, characterized in that, The first information indicates a bitmap of P bits, and the second symbol position is the symbol position corresponding to the bit with a first value among the P bits, where P is the number of symbols included in the time unit.

17. The method according to any one of claims 12 to 16, characterized in that, The first DMRS is used for data demodulation of the first PDSCH, and the frequency domain resources at the first symbol location are unavailable for the first PDSCH.

18. The method according to any one of claims 12 to 17, characterized in that, The first DMRS is used for data demodulation of the first PDSCH. The configuration information is also used to determine the position of the third symbol. The position of the third symbol overlaps with the position of the first symbol in the time domain. If the position of the third symbol is not available for the first PDSCH, the position of the second symbol does not overlap with the position of the third symbol in the time domain.

19. The method according to claim 18, characterized in that, The third symbol position has non-overlapping frequency domain resources and overlapping frequency domain resources with the first symbol position. The non-overlapping frequency domain resources are available to the first PDSCH, while the overlapping frequency domain resources are not available to the first PDSCH.

20. The method according to claim 19, characterized in that, The method further includes: Information is sent indicating at least one code division multiplexing (CDM) group and the type of the at least one CDM group, the at least one CDM group and the type of the at least one CDM group being used to determine the overlapping frequency domain resources.

21. The method according to claim 19 or 20, characterized in that, The third symbol position is the symbol position of the second DMRS. The second DMRS is used for data demodulation of the second PDSCH of the second terminal device, and the first DMRS is used for data demodulation of the first PDSCH of the first terminal device. The first terminal device uses the first RAT, and the second terminal device uses the second RAT.

22. The method according to any one of claims 12 to 21, characterized in that, The first DMRS includes a pre-DMRS and / or an additional DMRS.

23. A communication device, characterized in that, include: A processor coupled to a memory for storing a computer program, wherein when the processor invokes the computer program, the communication device performs the method of any one of claims 1 to 11, or performs the method of any one of claims 12 to 22.

24. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when run on a computer, causes the method of any one of claims 1 to 11 to be performed, or causes the method of any one of claims 12 to 22 to be performed.

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