Communication method and device

Abstract

This application relates to the field of communication technology and discloses a communication method and apparatus. The method includes an access network device sending a first indication information to a terminal device and sending a second indication information to the terminal device. If the second indication information indicates a first value, the first indication information indicates a first port index group among a plurality of port index groups included in a first set. If the second indication information indicates a second value, the first indication information indicates a second port index group among a plurality of port index groups included in a second set. The first port index group and the second port index group have an association relationship. According to the above method, by establishing an association relationship between the first port index group and the second port index group, the port index group indicated by the first indication information can be interpreted differently for different values ​​indicated by the second indication information. Therefore, after port extension, the indication overhead can be effectively reduced while indicating the ports assigned to the terminal device.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Chinese Patent Application No. 202210435803.4, entitled “COMMUNICATION METHOD AND APPARATUS,” filed with the China State Intellectual Property Office on April 24, 2022, which is hereby incorporated by reference in its entirety.

[0002] This application relates to the field of communications technology, and in particular to communications methods and devices. [Background technology]

[0003] A demodulation reference signal (DMRS) may be used to estimate the equivalent channel of a data channel or a control channel. The data channel may be, for example, a physical uplink shared channel (PUSCH) or a physical downlink shared channel (PDSCH), and the control channel may be, for example, a physical downlink control channel (PDCCH).

[0004] Take downlink data transmission as an example. When transmitting data to a terminal device via a PDSCH, the access network device may perform precoding of the data based on downlink channel state information (CSI). Furthermore, the access network device may assign a DMRS port to the terminal device and transmit a DMRS to the terminal device via a PDSCH on a time-frequency resource corresponding to the DMRS port. The same signal processing, such as precoding, is usually performed on the DMRS and data. Thus, after receiving the DMRS corresponding to the DMRS port, the terminal device may obtain an estimate for the equivalent channel according to a channel estimation algorithm, and complete data demodulation based on the equivalent channel.

[0005] However, it is still necessary to further consider how the access network device indicates to the terminal device the DMRS port assigned to the terminal device after DMRS port expansion. Summary of the Invention

[0006] This application provides a communication method and apparatus for indicating to a terminal device the ports assigned to the terminal device after port expansion.

[0007] According to a first aspect, an embodiment of the present application provides a communication method. The method may be applied to an access network device or a module (e.g., a chip) in the access network device. For example, the method is applied to the access network device. In the method, the access network device may send a first indication information to a terminal device and send a second indication information to the terminal device. If the second indication information indicates a first value, the first indication information indicates a first port index group among a plurality of port index groups included in a first set. If the second indication information indicates a second value, the first indication information indicates a second port index group among a plurality of port index groups included in a second set. The first port index group and the second port index group have an association relationship.

[0008] According to the above solution, by establishing an association relationship between the first port index group and the second port index group, the DMRS port index group indicated by the first indication information is interpreted differently for different values ​​indicated by the second indication information, so that after port extension, the indication overhead can be effectively reduced while indicating the ports allocated to the terminal device.

[0009] In one possible design, the association relationship is such that a one-to-one correspondence exists between port indexes in the first port index group and port indexes in the second port index group.

[0010] For example, the port indexes in the multiple port index groups included in the first set are all existing DMRS port indexes, and the port indexes in the multiple port index groups included in the second set are all newly added DMRS port indexes. When the second indication information indicates a first value, the first port index group indicated by the first indication information includes the existing DMRS port indexes, and when the second indication information indicates a second value, the second port index group indicated by the first indication information includes the newly added DMRS port indexes, so that the access network device can better ensure channel estimation performance without simultaneously allocating the existing DMRS port and the newly added DMRS port to the terminal device.

[0011] In one possible design, there is an offset between the port indexes in the first port index group and the port indexes in the second port index group.

[0012] In one possible design, the first set corresponds to a plurality of port indexes, each of a plurality of port index groups included in the first set includes at least one of the plurality of port indexes, and the offset is equal to the number of port indexes corresponding to the first set.

[0013] The number of port indexes corresponding to the first set may be different from the number of port index groups included in the first set. For example, the port indexes corresponding to the first set include DMRS port indexes “0-3” (i.e., the number of port indexes corresponding to the first set is 4). In this case, the first set may include 12 port index groups. See Table 3A for details.

[0014] In one possible design, the offset value is 4, 8, 6, or 12.

[0015] In one possible design, the association relationship is that the first port index group is a subset of the second port index group.

[0016] In one possible design, the second port index group includes a port index in the first port index group and further includes a port index corresponding to the port index in the first port index group, the first port index group includes the first port index, and there is an offset between the port index corresponding to the first port index and the first port index.

[0017] In one possible design, the second indication information is carried in a radio resource control (RRC) message or a downlink control information (DCI).

[0018] In one possible design, the first indication indicates a first index value, the first index value being associated with the first port index group and the second port index group.

[0019] In one possible design, the first port index group and the second port index group correspond to the same time-frequency resource, the first port index group corresponds to a first cover code sequence, the second port index group corresponds to a second cover code sequence, and the first cover code sequence is orthogonal to the second cover code sequence.

[0020] In one possible design, the method further includes sending third indication information to the terminal device, where if the first indication information indicates the first port index group, the third indication information indicates whether the second port index group is assigned to another terminal device on the time-frequency resources assigned to the terminal device, or if the first indication information indicates the second port index group, the third indication information indicates whether the first port index group is assigned to another terminal device on the time-frequency resources assigned to the terminal device.

[0021] According to the above solution, the access network device can send third indication information to the terminal device, so that the terminal device can perform channel estimation in a corresponding manner based on the third indication information. For example, if the third indication information indicates that the second port index group (or the first port index group) is not assigned to another terminal device on the time-frequency resource assigned to the terminal device, the terminal device does not need to consider despreading of the outer cover code during channel estimation based on the third indication information, so that the channel estimation is more conveniently performed. In another example, if the third indication information indicates that the second port index group (or the first port index group) is assigned to another terminal device on the time-frequency resource assigned to the terminal device, the terminal device can consider despreading of the inner cover code and the outer cover code during channel estimation based on the third indication information to reduce interference between the existing DMRS port and the newly added DMRS port.

[0022] According to a second aspect, an embodiment of the present application provides a communication method. The method may be applied to a terminal device or a module (e.g., a chip) in the terminal device. For example, the method is applied to a terminal device. In the method, a terminal may receive first indication information from an access network device and receive second indication information from the access network device. If the second indication information indicates a first value, the first indication information indicates a first port index group among a plurality of port index groups included in a first set. If the second indication information indicates a second value, the first indication information indicates a second port index group among a plurality of port index groups included in a second set. The first port index group and the second port index group have an association relationship.

[0023] In one possible design, the association relationship is such that a one-to-one correspondence exists between port indexes in the first port index group and port indexes in the second port index group.

[0024] In one possible design, there is an offset between the port indexes in the first port index group and the port indexes in the second port index group.

[0025] In one possible design, the first set corresponds to a plurality of port indexes, each of a plurality of port index groups included in the first set includes at least one of the plurality of port indexes, and the offset is equal to the number of port indexes corresponding to the first set.

[0026] In one possible design, the offset value is 4, 8, 6, or 12.

[0027] In one possible design, the association relationship is that the first port index group is a subset of the second port index group.

[0028] In one possible design, the second port index group includes port indexes in the first port index group and further includes port indexes that correspond to the port indexes in the first port index group.

[0029] The first port index group includes a first port index, and there is an offset between the port index corresponding to the first port index and the first port index.

[0030] In one possible design, the second indication information is carried in an RRC message or a DCI.

[0031] In one possible design, the first indication indicates a first index value, the first index value being associated with the first port index group and the second port index group.

[0032] In one possible design, the first port index group and the second port index group correspond to the same time-frequency resource, the first port index group corresponds to a first cover code sequence, the second port index group corresponds to a second cover code sequence, and the first cover code sequence is orthogonal to the second cover code sequence.

[0033] In one possible design, the method further includes receiving third indication information from the access network device, where if the first indication information indicates the first port index group, the third indication information indicates whether a second port index group is assigned to another terminal device on the time-frequency resources assigned to the terminal device, or if the first indication information indicates the second port index group, the third indication information indicates whether the first port index group is assigned to another terminal device on the time-frequency resources assigned to the terminal device.

[0034] It can be understood that the method in the second aspect corresponds to the method in the first aspect. For the advantageous effects of the related technical features, please refer to the description in the first aspect. Details will not be described again.

[0035] According to a third aspect, the present application provides a communication device, the communication device having a function for implementing the first aspect. For example, the communication device includes corresponding modules, units or means for performing the operations in the first aspect. The modules, units or means may be implemented by software, hardware, or by hardware executing corresponding software.

[0036] In one possible design, the communication device includes a processing unit and a communication unit. The communication unit may be configured to transmit / receive signals to perform communication between the communication device and another device. The processing unit may be configured to perform some internal operations of the communication device. Functions performed by the processing unit and the communication unit may correspond to operations in the first aspect.

[0037] In one possible design, the communication device includes a processor, which may be coupled to a memory. The memory may store computer programs or instructions necessary to implement the functionality of the first aspect. The processor may execute the computer programs or instructions stored in the memory. When the computer programs or instructions are executed, the communication device is enabled to perform a method according to any of the possible designs or implementations of the first aspect.

[0038] In one possible design, the communication device includes a processor and a memory. The memory may store computer programs or instructions necessary to implement the functionality of the first aspect. The processor may execute the computer programs or instructions stored in the memory. When the computer programs or instructions are executed, the communication device is enabled to perform a method according to any of the possible designs or implementations of the first aspect.

[0039] In one possible design, the communications device includes a processor and an interface circuit, the processor configured to communicate with another device via the interface circuit and to perform a method according to any of the possible designs or implementations of the first aspect.

[0040] According to a fourth aspect, the present application provides a communication device, the communication device having a function for implementing the second aspect, for example the communication device includes corresponding modules, units or means for performing the operations in the second aspect, the functions, units or means being implemented by software, hardware or by the hardware executing the corresponding software.

[0041] In one possible design, the communication device includes a processing unit and a communication unit. The communication unit may be configured to transmit / receive signals to perform communication between the communication device and another device. For example, the communication unit is configured to transmit system information to a terminal device. The processing unit may be configured to perform some internal operations of the communication device. Functions performed by the processing unit and the communication unit may correspond to operations in the second aspect.

[0042] In one possible design, the communications device may include a processor, the processor may be coupled to a memory. The memory may store computer programs or instructions necessary to implement the functionality of the second aspect. The processor may execute the computer programs or instructions stored in the memory. When the computer programs or instructions are executed, the communications device is enabled to perform the method of any possible design or implementation of the second aspect.

[0043] In one possible design, the communication device includes a processor and a memory. The memory may store computer programs or instructions necessary to implement the functionality of the second aspect. The processor may execute the computer programs or instructions stored in the memory. When the computer programs or instructions are executed, the communication device is enabled to perform the method of any possible design or implementation of the second aspect.

[0044] In one possible design, the communications device includes a processor and an interface circuit, the processor configured to communicate with another device via the interface circuit and to perform a method according to any of the possible designs or implementations of the second aspect.

[0045] It can be understood that in the third or fourth aspect, the processor can be implemented by hardware or software. When the processor is implemented by hardware, the processor can be a logic circuit, an integrated circuit, or the like. When the processor is implemented by software, the processor can be a general-purpose processor, and is implemented by reading software code stored in a memory. There can also be one or more processors and one or more memories. The memory can be integrated with the processor, or the memory and the processor can be located separately. In a particular implementation process, the memory and the processor can be integrated in one chip, or can be located on different chips. The type of memory and the manner in which the memory and the processor are located are not limited in the embodiment of this application.

[0046] According to a fifth aspect, the application provides a communication system, which may include a communication device according to the third aspect and a communication device according to the fourth aspect.

[0047] According to a sixth aspect, the application provides a computer readable storage medium storing computer readable instructions which, when read and executed by a computer, enable the computer to carry out a method according to the first aspect and any of the possible designs of the first aspect or any of the possible designs of the second aspect and any of the possible designs of the second aspect.

[0048] According to a seventh aspect, the application provides a computer program product which, when read and executed by a computer, enables the computer to carry out a method according to the first aspect and any of the possible designs of the first aspect or any of the possible designs of the second aspect.

[0049] According to an eighth aspect, the application provides a chip, the chip including a processor, coupled to a memory, for reading and executing a software program stored in the memory to implement a method according to the first aspect and any of the possible designs of the first aspect or the second aspect and any of the possible designs of the second aspect. [Brief description of the drawings]

[0050] [Figure 1] FIG. 1 is a diagram of a network architecture to which an embodiment of this application is applicable. [Diagram 2] FIG. 2 is a diagram of DMRS resource mapping according to one embodiment of the present application. [Diagram 3] 2 is a schematic flowchart corresponding to a DMRS port indication method according to an embodiment of the present application; [Figure 4] FIG. 2 is a diagram of DMRS port expansion according to one embodiment of the present application. [Diagram 5] FIG. 2 is another diagram of DMRS port expansion according to an embodiment of the present application. [Figure 6] 1 is a schematic flowchart corresponding to a communication method according to an embodiment of the present application. [Figure 7] FIG. 2 is a block diagram of a possible example of an apparatus according to an embodiment of the present application. [Figure 8] FIG. 2 is a diagram of the configuration of an access network device according to one embodiment of the present application. [Figure 9] FIG. 2 is a diagram of a configuration of a terminal device according to one embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0051] Hereinafter, the technical solutions in the embodiments of this application will be described with reference to the accompanying drawings in the embodiments of this application.

[0052] FIG. 1 is an architecture diagram of a communication system to which an embodiment of this application is applied. As shown in FIG. 1, the communication system 1000 includes a radio access network 100 and a core network 200. Optionally, the communication system 1000 may further include the Internet 300. The radio access network 100 may include at least one radio access network device, for example 110a and 110b in FIG. 1, and may further include at least one terminal device, for example 120a to 120j in FIG. 1. Here, 110a is a base station, 110b is a micro base station, 120a, 120e, 120f, and 120j are mobile phones, 120b is a vehicle, 120c is a fuel dispenser, 120d is a home access point (HAP) located indoors or outdoors, 120g is a notebook computer, 120h is a printer, and 120i is an unmanned aerial vehicle.

[0053] In FIG. 1, the terminal device can be connected to a radio access network device, and the radio access network device can be connected to a core network device in a core network. The core network device and the radio access network device may be different independent physical devices, or the function of the core network device and the logical function of the radio access network device may be integrated into the same physical device, or some functions of the core network device and some functions of the radio access network device may be integrated into one physical device. The terminal devices can be connected to each other in a wired or wireless manner, and the radio access network devices can be connected to each other in a wired or wireless manner. FIG. 1 is just one diagram. The communication system may further include other devices not depicted in FIG. 1, such as a wireless relay device and a wireless backhaul device.

[0054] In the following, a radio access network device and a terminal device are described.

[0055] (1) Radio Access Network Devices

[0056] The radio access network device may also be referred to as an access network device. The access network device may be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next generation NodeB (gNB) in a 5th generation (5G) mobile communication system, a base station in a 6th generation (6G) mobile communication system, a base station in a future mobile communication system, an access node in a wireless fidelity (Wi-Fi) system, or the like. The access network device may instead be a module or unit completing a part of the function of a base station, for example, a central unit (CU) or a distributed unit (DU). The access network device may be a macro base station (e.g., 110a in FIG. 1), a micro base station or an indoor base station (e.g., 110b in FIG. 1), or a relay node, a donor node, or the like. The specific technology used by the access network device and the specific device configuration are not limited to the embodiments of this application.

[0057] In the embodiments of this application, an apparatus configured to implement the functions of an access network device may be an access network device, or may be an apparatus capable of supporting an access network device in implementing functions, such as a chip system. The apparatus may be installed in an access network device. The chip system may include a chip, or may include a chip and another discrete device. In the technical solution provided in the embodiments of this application, the technical solution provided in the embodiments of this application is described by using an example in which the apparatus configured to implement the functions of an access network device is an access network device.

[0058] (2) Terminal Device

[0059] The terminal device may also be referred to as a terminal, user equipment (UE), mobile station, or mobile terminal. The terminal device may be widely used in various scenarios, such as device-to-device (D2D) scenarios, vehicle-to-everything (V2X) communication scenarios, machine-type communication (MTC) scenarios, internet of things (IOT) scenarios, virtual reality scenarios, augmented reality scenarios, industrial control scenarios, autonomous driving scenarios, telemedicine scenarios, smart grid scenarios, smart furniture scenarios, smart office scenarios, smart wearable scenarios, smart transportation scenarios, and smart city scenarios. The terminal device may be a mobile phone, a tablet computer, a computer with a wireless transceiver function, a wearable device, a vehicle, an unmanned aerial vehicle, a helicopter, an airplane, a ship, a robot, a robot arm, a smart home device, or the like. The specific technology and the specific device form used by the terminal device are not limited in the embodiments of this application.

[0060] In the embodiments of this application, the apparatus configured to implement the functions of the terminal device may be a terminal device, or may be an apparatus that can support the terminal device in implementing functions, such as a chip system. The apparatus may be installed in the terminal device. The technical solution provided in the embodiments of this application is described by using an example in which the apparatus configured to implement the functions of the terminal device is a terminal device.

[0061] Also, the same terminal device or access network device may provide different functions in different application scenarios. For example, the mobile phones in FIG. 1 include 120a, 120e, 120f, and 120j. Mobile phone 120a may access base station 110a, connect to vehicle 120b, communicate directly with mobile phone 120e, and access the HAP. Mobile phone 120e may access the HAP and communicate directly with mobile phone 120a. Mobile phone 120f may access micro base station 110b, connect to notebook computer 120g, and connect to printer 120h. Mobile phone 120j may control unmanned aerial vehicle 120i.

[0062] The roles of the access network device and the terminal device may be relative. For example, the helicopter or unmanned aerial vehicle 120i in FIG. 1 may be configured as a mobile base station. For the terminal device 120j that accesses the radio access network 100 via the helicopter or unmanned aerial vehicle 120i, the terminal device 120i is a base station. However, for the base station 110a, the terminal device 120i is a terminal device. In other words, the base station 110a communicates with the terminal device 120i via a wireless air interface protocol. Certainly, the communication between the base stations 110a and 120i may be based on an interface protocol between the base stations instead. In this case, the terminal device 120i is also a base station for the base station 110a. Thus, both the radio access network device and the terminal device may be collectively referred to as a communication device, and the terminal devices 110a and 110b in FIG. 1 may be referred to as a communication device having a base station function, and the terminal devices 120a to 120j in FIG. 1 may be referred to as a communication device having a terminal device function.

[0063] The access network device and the terminal device may be in a fixed location or may be mobile. The access network device and the terminal device may be deployed on land, including indoor or outdoor scenarios and handheld or vehicle-mounted scenarios, or on water, or on an airplane, balloon, or satellite in the air. The application scenario of the access network device and the terminal device is not limited in the embodiments of this application.

[0064] The communication between the access network device and the terminal device, between the access network devices, or between the terminal devices may be performed using a licensed spectrum, an unlicensed spectrum, or both the licensed spectrum and the unlicensed spectrum, and may be performed using a spectrum below 6 gigahertz (GHz), a spectrum above 6 GHz, or both the spectrum below 6 GHz and the spectrum above 6 GHz. The frequency resources used for wireless communication are not limited in the embodiments of this application.

[0065] The communication system shown in FIG. 1 may support various radio access technologies (RATs). For example, the communication system shown in FIG. 1 may be a 4th generation (4G) communication system (which may also be referred to as a long term evolution (LTE) communication system), a 5G communication system (which may also be referred to as a new radio (NR) communication system), or a future-oriented evolution system. The communication systems and service scenarios described in the embodiments of this application are intended to more clearly explain the technical solutions in the embodiments of this application, and do not constitute limitations on the technical solutions provided in the embodiments of this application. It is understood by those skilled in the art that the technical solutions provided in the embodiments of this application are also applicable to similar technical challenges when communication systems evolve and new service scenarios emerge.

[0066] Hereinafter, first, the relevant technical features in the embodiments of this application will be described, which are intended to facilitate the understanding of the embodiments of this application, and should not be regarded as limitations on the scope of protection claimed in this application.

[0067] 1.DMRS

[0068] In the communication system shown in FIG. 1, the access network device can transmit control information to the terminal device via a control channel (e.g., PDCCH) to assign transmission parameters of a data channel to the terminal device. The data channel can be, for example, a PDSCH or a PUSCH. For example, the control information indicates a time domain symbol and / or a frequency domain resource block (RB) to which the data channel is mapped, so that the access network device and the terminal device can transmit downlink data (e.g., data carried on a PDSCH) and / or uplink data (e.g., data carried on a PUSCH) on the assigned time-frequency resource via the data channel. In an embodiment of this application, the time domain symbol can be an orthogonal frequency division multiplexing (OFDM) symbol or a discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbol.

[0069] Also, a control channel (e.g., PDCCH) or a data channel (e.g., PDSCH or PUSCH) can carry a reference signal, e.g., a demodulation reference signal (DMRS). Using the data channel as an example, the DMRS can be used to estimate an equivalent channel of a data signal carried on the data channel and to detect and demodulate the data on the data channel. To ensure that the DMRS and data go through the same equivalent channel, the same signal processing, e.g., precoding, is usually performed on the DMRS and the data.

[0070] Suppose the transmitting end transmits a DMRS vector s and a data signal (or data symbol) vector x, the DMRS and the data signal are precoded in the same way (e.g., multiplied by the same precoding matrix P), and the processed data signal and DMRS are transmitted simultaneously through the same channel. The corresponding received signal vector at the receiving end is:

[0071]

number

[0072] y represents the data signal vector received by the receiving end, r represents the DMRS vector received by the receiving end, H represents the channel through which the data signal and DMRS actually pass, P represents the precoding matrix, and n represents the noise signal vector.

[0073] Both data and DMRS are equivalent channels:

[0074]

number

[0075] 2.DMRS port

[0076] A port may be an antenna port, and a port may be understood as a transmitting antenna identified by a receiving end or a transmitting antenna that may be distinguished in space. One port may be configured for each virtual antenna, and each virtual antenna may be a weighted combination of multiple physical antennas. A port used to transmit a reference signal may be referred to as a reference signal port. The reference signal may be, for example, a DMRS, a channel state information reference signal (CSI-RS), or a sounding reference signal (SRS). This is not particularly limited.

[0077] Take a DMRS port as an example. Different DMRS ports can be distinguished by using different indexes (or port numbers). For example, the index of a DMRS port can be 1000+X, where the value of X can be an integer equal to or greater than 0. 1000+X can also be written as X. When the index of a DMRS port is 1000+X, the DMRS port can be referred to as DMRS port 1000+X, or can be referred to as DMRS port X. In other words, in the embodiment of this application, 1000+X and X can be understood as the index of the same DMRS port.

[0078] In the following, an example is described in which the port is a DMRS port. It can be understood that the method provided in the embodiment of this application is also applicable to other possible reference signal ports, such as a CSI-RS port or an SRS port, in addition to the DMRS port.

[0079] 3. Time-frequency resource mapping of DMRS ports

[0080] One DMRS port may correspond to one or more DMRS signal symbols (also called DMRS modulation symbols, or sometimes called DMRS symbols for short). To perform channel estimation on different time-frequency resources, multiple DMRS symbols corresponding to a DMRS port may be transmitted on multiple time-frequency resources. Furthermore, to ensure channel estimation quality, different DMRS ports are usually orthogonal ports to avoid interference between different DMRS ports.

[0081] A plurality of DMRS symbols corresponding to one DMRS port may correspond to one DMRS sequence, and one DMRS sequence includes a plurality of DMRS sequence elements. The DMRS sequence corresponding to one DMRS port may be multiplied with a corresponding cover code sequence and then mapped to a corresponding time-frequency resource according to a time-frequency resource mapping rule. For example, the m-th DMRS sequence element r(m) in the DMRS sequence corresponding to DMRS port p may be mapped to a corresponding time-frequency resource according to a time-frequency resource mapping rule with its index (k,l). p,μ The kth element can be mapped to a resource element (RE) whose index is (k,l). p,μ The RE, , may correspond to a time-domain symbol whose index is l in a time-domain slot and a subcarrier whose index is k in a frequency domain. The time-frequency resource mapping rule is expressed by the following Equation 1:

[0082]

number

[0083] p is the index of the DMRS port, μ is the subcarrier spacing parameter,

[0084]

number

[0085]

number

[0086]

number

[0087] In addition, the w corresponding to the DMRS port p f (k'), w t The values ​​of (l') and Δ relate to the DMRS configuration type, see the description of the DMRS configuration type for details.

[0088] 4.DMRS Configuration Types

[0089] The DMRS configuration types may include configuration type 1 and configuration type 2. Different configuration types support different numbers of orthogonal DMRS ports and different time-frequency resource mapping rules. Hereinafter, configuration type 1 and configuration type 2 will be described separately.

[0090] (1) Configuration Type 1

[0091] In configuration type 1, the w corresponding to DMRS port p f (k'), w t The values ​​of (l') and Δ may be determined according to Table 1 below.

[0092] [Table 1]

[0093] λ is the index of a code division multiplexing (CDM) group (sometimes called an orthogonal multiplexing group) to which the DMRS port p belongs, and the time-frequency resources occupied by DMRS ports in the same CDM group are the same. The "time-frequency resources occupied by a DMRS port" may also be replaced with "time-frequency resources corresponding to a DMRS port" or "time-frequency resources to which a DMRS port is mapped."

[0094] The time-frequency resources to which the DMRS sequences corresponding to different DMRS ports are mapped may be determined based on the above-mentioned time-frequency resource mapping rule (i.e., Equation 1) and the parameter values ​​in Table 1, as shown in (a) of FIG. 2. The time-domain symbol length occupied by a DMRS port (or the number of time-domain symbols occupied by a DMRS port) may be 1 or 2. If the time-domain symbol length occupied by a DMRS port is 1, the DMRS may be referred to as a single-symbol DMRS. If the time-domain symbol length occupied by a DMRS port is 2, the DMRS may be referred to as a double-symbol DMRS. Hereinafter, single-symbol DMRS and double-symbol DMRS will be described separately.

[0095] (1.1) Single-symbol DMRS

[0096] A single-symbol DMRS (corresponding to l′=0) supports up to four orthogonal DMRS ports. The four orthogonal DMRS ports may be divided into two CDM groups: CDM group 0 and CDM group 1. CDM group 0 includes DMRS port 0 and DMRS port 1, and CDM group 1 includes DMRS port 2 and DMRS port 3. CDM group 0 and CDM group 1 are frequency division multiplexed (mapped to different frequency domain resources). DMRS ports included in a CDM group are mapped to the same time-frequency resources. To ensure the orthogonality of DMRS ports in a CDM group and suppress interference between DMRSs transmitted on different DMRS ports, DMRS sequences corresponding to DMRS ports included in a CDM group are differentiated by using cover code sequences. The cover code sequences may be orthogonal cover code (OCC) sequences.

[0097] Specifically, DMRS Port 0 and DMRS Port 1 are located in the same RE, and resource mapping is performed in a comb-like manner in the frequency domain. Specifically, adjacent frequency domain resources occupied by DMRS Port 0 and DMRS Port 1 are separated by one subcarrier. Two adjacent subcarriers occupied by a DMRS Port in the frequency domain correspond to a frequency domain cover code sequence whose length is 2, e.g., (+1, +1) or (+1, -1). One time domain symbol occupied by a DMRS Port in the time domain corresponds to a time domain cover code sequence whose length is 1, e.g., (+1). Based on the frequency domain cover code sequence and the time domain cover code sequence, it can be obtained that the length of the cover code sequence corresponding to the DMRS Port is 2 (the cover code sequence corresponding to the DMRS Port can be formed by the Kronecker product of the frequency domain cover code sequence and the time domain cover code sequence). For example, for subcarrier 0 and subcarrier 2 corresponding to time domain symbol 0, DMRS Port 0 and DMRS Port 1 can be code division multiplexed by using a cover code sequence whose length is 2. The cover code sequence corresponding to DMRS port 0 is (+1, +1), and the cover code sequence corresponding to DMRS port 1 is (+1, -1).

[0098] Similarly, DMRS Port 2 and DMRS Port 3 are located in the same RE and are comb-like mapped in the frequency domain to the REs not occupied by DMRS Port 0 and DMRS Port 1. For example, for subcarrier 1 and subcarrier 3 corresponding to time domain symbol 0, DMRS Port 2 and DMRS Port 3 may be code division multiplexed by using a cover code sequence whose length is 2. The cover code sequence corresponding to DMRS Port 2 is (+1, +1), and the cover code sequence corresponding to DMRS Port 3 is (+1, -1).

[0099] (1.2) Double Symbol DMRS

[0100] The double-symbol DMRS (corresponding to l′=0 or 1) supports up to eight orthogonal DMRS ports. The eight orthogonal DMRS ports are divided into two CDM groups: CDM group 0 and CDM group 1. CDM group 0 includes DMRS port 0, DMRS port 1, DMRS port 4, and DMRS port 5. CDM group 1 includes DMRS port 2, DMRS port 3, DMRS port 6, and DMRS port 7. CDM group 0 and CDM group 1 are frequency division multiplexed, and the DMRS ports included in a CDM group are mapped to the same time-frequency resources, and the DMRS sequences corresponding to the DMRS ports included in a CDM group are distinguished by using cover code sequences.

[0101] Specifically, DMRS Port 0, DMRS Port 1, DMRS Port 4, and DMRS Port 5 are located in the same RE, and resource mapping is performed in a comb-like manner in the frequency domain. Specifically, adjacent frequency domain resources occupied by DMRS Port 0, DMRS Port 1, DMRS Port 4, and DMRS Port 5 are separated by one subcarrier. Two adjacent subcarriers occupied by a DMRS port in the frequency domain correspond to a frequency domain cover code sequence whose length is 2, e.g., (+1, +1) or (+1, -1). Two adjacent time domain symbols occupied by a DMRS port in the time domain correspond to a time domain cover code sequence whose length is 2, e.g., (+1, +1) or (+1, -1). Based on the frequency domain cover code sequence and the time domain cover code sequence, it can be obtained that the length of the cover code sequence corresponding to the DMRS port is 4 (the cover code sequence corresponding to the DMRS port can be formed by the Kronecker product of the frequency domain cover code sequence and the time domain cover code sequence). For example, for subcarrier 0 and subcarrier 2 corresponding to time domain symbol 0 and time domain symbol 1, DMRS Port 0, DMRS Port 1, DMRS Port 4, and DMRS Port 5 may be code division multiplexed by using a cover code sequence whose length is 4. The cover code sequence corresponding to DMRS Port 0 is (+1, +1, +1, +1), the cover code sequence corresponding to DMRS Port 1 is (+1, +1, -1, -1), the cover code sequence corresponding to DMRS Port 4 is (+1, -1, +1, -1), and the cover code sequence corresponding to DMRS Port 5 is (+1, -1, -1, +1).

[0102] Similarly, DMRS Port 2, DMRS Port 3, DMRS Port 6, and DMRS Port 7 are located in the same RE and are comb-like mapped in the frequency domain to the subcarriers not occupied by DMRS Port 0, DMRS Port 1, DMRS Port 4, and DMRS Port 5. For subcarrier 1 and subcarrier 3 corresponding to time domain symbol 0 and time domain symbol 1, DMRS Port 2, DMRS Port 3, DMRS Port 6, and DMRS Port 7 may be code division multiplexed by using a cover code sequence whose length is four. The cover code sequence corresponding to DMRS port 2 is (+1,+1,+1,+1), the cover code sequence corresponding to DMRS port 3 is (+1,+1,-1,-1), the cover code sequence corresponding to DMRS port 6 is (+1,-1,+1,-1), and the cover code sequence corresponding to DMRS port 7 is (+1,-1,-1,+1).

[0103] (2) Configuration Type 2

[0104] In configuration type 2, the w f (k'), w t The values ​​of (l') and Δ can be determined according to Table 2.

[0105] [Table 2]

[0106] λ is the index of the CDM group to which DMRS port p belongs, and DMRS ports in the same CDM group occupy the same time-frequency resources.

[0107] The time-frequency resources to which the DMRS sequences corresponding to different DMRS ports are mapped may be determined based on the above time-frequency resource mapping rule (i.e., Equation 1) and the parameter values ​​in Table 1, as shown in FIG. 2(b). The time-domain symbol length occupied by a DMRS port may be 1 or 2. If the time-domain symbol length occupied by a DMRS port is 1, the DMRS may be referred to as a single-symbol DMRS. If the time-domain symbol length occupied by a DMRS port is 2, the DMRS may be referred to as a double-symbol DMRS. Hereinafter, single-symbol DMRS and double-symbol DMRS will be described separately.

[0108] (2.1) Single-symbol DMRS

[0109] The single-symbol DMRS supports up to six orthogonal DMRS ports. The six orthogonal DMRS ports are divided into three CDM groups: CDM group 0, CDM group 1, and CDM group 2. CDM group 0 includes DMRS port 0 and DMRS port 1, CDM group 1 includes DMRS port 2 and DMRS port 3, and CDM group 2 includes DMRS port 4 and DMRS port 5. The CDM groups are frequency division multiplexed, and the DMRSs corresponding to the DMRS ports included in a CDM group are mapped to the same time-frequency resource. The DMRS sequences corresponding to the DMRS ports included in a CDM group are differentiated by using cover code sequences. The DMRS sequences corresponding to the DMRS ports are mapped to multiple resource subblocks including two consecutive subcarriers in the frequency domain, and adjacent resource subblocks are separated by four subcarriers in the frequency domain.

[0110] Specifically, DMRS Port 0 and DMRS Port 1 are located in the same RE, and resource mapping is performed in a comb-like manner in the frequency domain. For example, the frequency domain resource granularity is 1RB, and DMRS Port 0 and DMRS Port 1 occupy subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7. DMRS Port 2 and DMRS Port 3 occupy subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9. DMRS Port 4 and DMRS Port 5 occupy subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11. Two DMRS ports included in a CDM group are code division multiplexed on two adjacent subcarriers by using a cover code sequence whose length is 2. For example, the cover code sequences corresponding to the two DMRS ports are (+1, +1) and (+1, -1), respectively.

[0111] (2.2) Double Symbol DMRS

[0112] The double-symbol DMRS supports up to 12 orthogonal DMRS ports. The 12 orthogonal DMRS ports are divided into three CDM groups. CDM group 0 includes DMRS Port 0, DMRS Port 1, DMRS Port 6, and DMRS Port 7. CDM group 1 includes DMRS Port 2, DMRS Port 3, DMRS Port 8, and DMRS Port 9. CDM group 2 includes DMRS Port 4, DMRS Port 5, DMRS Port 10, and DMRS Port 11. The CDM groups are frequency division multiplexed, and the DMRSs corresponding to the DMRS ports included in the CDM group are mapped to the same time-frequency resources, and the DMRS sequences corresponding to the DMRS ports included in the CDM group are differentiated by using cover code sequences. The DMRS sequences corresponding to the DMRS ports are mapped to multiple resource subblocks including two consecutive subcarriers in the frequency domain, and adjacent resource subblocks are separated by four subcarriers in the frequency domain.

[0113] Specifically, DMRS Port 0, DMRS Port 1, DMRS Port 6, and DMRS Port 7 are located in the same RE, and resource mapping is performed in a comb-like manner in the frequency domain. For example, the frequency domain resource granularity is 1RB. DMRS Port 0, DMRS Port 1, DMRS Port 6, and DMRS Port 7 occupy subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7 corresponding to time domain symbol 0 and time domain symbol 1. DMRS Port 2, DMRS Port 3, DMRS Port 8, and DMRS Port 9 occupy subcarrier 2, subcarrier 3, subcarrier 8, and subcarrier 9 corresponding to time domain symbol 1 and time domain symbol 2. DMRS Port 4, DMRS Port 5, DMRS Port 10, and DMRS Port 11 occupy subcarrier 4, subcarrier 5, subcarrier 10, and subcarrier 11 corresponding to time domain symbol 1 and time domain symbol 2. The four DMRS ports included in the CDM group are code division multiplexed on two adjacent subcarriers corresponding to two time domain symbols by using a cover code sequence whose length is 4. For example, the cover code sequences corresponding to the four DMRS ports are (+1,+1,+1,+1), (+1,+1,-1,-1), (+1,-1,+1,-1), and (+1,-1,-1,+1), respectively.

[0114] 5.DMRS Port Indication

[0115] When an access network device communicates with a terminal device via a control channel or a data channel, the access network device needs to indicate to the terminal device the DMRS port assigned to the terminal device. With reference to Figure 3, the following describes one possible implementation of the access network device indicating to the terminal device the DMRS port assigned to the terminal device.

[0116] 3 is a schematic flow chart corresponding to a communication method according to an embodiment of this application. As shown in FIG. 3, the procedure may include the following steps:

[0117] S301: An access network device sends indication information 1 to a terminal device, where the indication information 1 indicates that the DMRS configuration type is configuration type 1 or configuration type 2. Correspondingly, the terminal device receives the indication information 1.

[0118] For example, the access network device may send the indication information 1 to the terminal device by using an RRC message.

[0119] S302: The access network device sends indication information 2 to the terminal device, where the indication information 2 indicates that the maximum symbol length occupied by the DMRS port is 1 or 2. Correspondingly, the terminal device receives the indication information 2.

[0120] Here, the maximum symbol length occupied by a DMRS port is the maximum symbol length (or number) that can be occupied by a DMRS. In one transmission scheduling, the symbol length actually occupied by a DMRSj transmitted by a transmitting end (e.g., an access network device or a terminal device) may be less than or equal to the maximum symbol length. For example, if the maximum symbol length is 2, the symbol length actually occupied by a DMRS transmitted by a transmitting end in one transmission scheduling may be 1 or 2. In another example, if the maximum symbol length is 1, the symbol length actually occupied by a DMRS transmitted by a transmitting end in one transmission scheduling may be 1.

[0121] For example, the access network device may send the indication information 2 to the terminal device by using an RRC message, where the indication information 1 and the indication information 2 may be carried in the same message, or may be carried in different messages.

[0122] It can be understood that S302 is an optional step. In other words, the access network device may not send the indication information 2 to the terminal device. In this case, the terminal device may consider that the maximum symbol length occupied by the DMRS port is 1 by default.

[0123] S303: The access network device sends indication information 3 to the terminal device, where the indication information 3 indicates an index value. Also, the terminal device may receive the indication information 3.

[0124] For example, the access network device may transmit the indication information 3 to the terminal device by using a media access control (MAC) layer message (e.g., a MAC control element (CE)) or a physical layer message (e.g., Downlink control information (DCI)).

[0125] S304: The terminal device determines a DMRS port allocated to the terminal device by the access network device based on the configuration type indicated by the indication information 1, the maximum symbol length occupied by the DMRS port indicated by the indication information 2, and the index value indicated by the indication information 3.

[0126] For example, after the terminal device determines the DMRS port allocated to the terminal device by the access network device, for downlink transmission, the terminal device may receive the DMRS from the access network device on the corresponding time-frequency resource based on the allocated DMRS port according to the DMRS symbol generation method and time-frequency resource mapping rule specified in the protocol, and perform a corresponding channel estimation procedure. For uplink transmission, the terminal device may transmit the DMRS to the access network device on the corresponding time-frequency resource based on the allocated DMRS port according to the DMRS symbol generation method and time-frequency resource mapping rule specified in the protocol.

[0127] With reference to Tables 3A to 6B, some possible implementations of a terminal device determining a DMRS port are described below.

[0128] (1) When the indication information 1 indicates a configuration type 1 and the maximum symbol length occupied by a DMRS port is 1, the terminal device may determine a DMRS port allocated to the terminal device by the access network device based on Table 3A or Table 3B and the index value indicated by the indication information 3. Whether the terminal device specifically uses Table 3A or Table 3B may be specified in a protocol. For example, when the terminal device receives a DCI and at least one field value (code point) in a “Transmission Configuration Indication” field in the DCI corresponds to two transmission configuration indication (TCI) states, the terminal device may use Table 3B; otherwise, the terminal device may use Table 3A.

[0129] [Table 3]

[0130] [Table 4]

[0131] Using Table 3A as an example. For example, when the index value indicated by the indication information 3 is “1”, the DMRS port index associated with the index value “1” in Table 3A is 1, so that the terminal device can determine that the DMRS port allocated to the terminal device by the access network device is DMRS port 1 among DMRS port 0 to DMRS port 3 corresponding to the single-symbol DMRS of Type 1. In another example, when the index value indicated by the indication information 3 is “2”, the DMRS port indexes associated with the index value “2” in Table 3A are 0 and 1, so that the terminal device can determine that the DMRS port allocated to the terminal device by the access network device includes DMRS port 0 and DMRS port 1 among DMRS port 0 to DMRS port 3 corresponding to the single-symbol DMRS of Type 1.

[0132] Also, in Table 3A and Table 3B, if the number of CDM groups without data is 1, the CDM group without data can be CDM group 0. If the number of CDM groups without data is 2, the CDM groups without data can include CDM group 0 and CDM group 1. If the number of CDM groups without data is 3, the CDM groups without data can include CDM group 0, CDM group 1, and CDM group 3. For the "number of CDM groups without data" in other tables in this embodiment of this application, please refer to the description herein.

[0133] (2) When the indication information 1 indicates the configuration type 1 and the maximum symbol length occupied by the DMRS port is 2, the terminal device may determine the DMRS port allocated to the terminal device by the access network device based on Table 4A or Table 4B and the index value indicated by the indication information 3. For whether the terminal device specifically uses Table 4A or Table 4B, please refer to the above description of whether the terminal device uses Table 3A or Table 3B.

[0134] [Table 5] TIFF2025515309000013.tif100170

[0135] [Table 6] TIFF2025515309000015.tif87170

[0136] Take the case of one codeword in Table 4A as an example. For example, when the index value indicated by the indication information 3 is “1”, the DMRS port index associated with the index value “1” in Table 4A is 1, and the symbol length occupied by the DMRS port associated with the index value “1” in Table 4A is 1, so the terminal device can determine that the DMRS port allocated to the terminal device by the access network device is DMRS port 1 among DMRS ports 0 to 3 corresponding to the single-symbol DMRS of Type 1. In another example, when the index value indicated by the indication information 3 is “12”, the DMRS port index associated with the index value “12” in Table 4A is 0, and the symbol length occupied by the DMRS port associated with the index value “12” in Table 4A is 2, so the terminal device can determine that the DMRS port allocated to the terminal device by the access network device is DMRS port 0 among DMRS ports 0 to DMRS ports 7 corresponding to the double-symbol DMRS of Type 1.

[0137] (3) If the indication information 1 indicates the configuration type 2 and the maximum symbol length occupied by the DMRS port is 1, the terminal device may determine the DMRS port allocated to the terminal device by the access network device based on Table 5A or Table 5B and the index value indicated by the indication information 3. For whether the terminal device specifically uses Table 5A or Table 5B, please refer to the above description of whether the terminal device uses Table 3A or Table 3B.

[0138] [Table 7]

[0139] [Table 8]

[0140] Taking the case of one codeword in Table 5A as an example, for example, when the index value indicated by the indication information 3 is “1”, the DMRS port index associated with the index value “1” in Table 5A is 1, so that the terminal device can determine that the DMRS port allocated to the terminal device by the access network device is DMRS port 1 among DMRS ports 0 to DMRS ports 5 corresponding to the single-symbol DMRS of Type 2.

[0141] (4) If the indication information 1 indicates the configuration type 2 and the maximum symbol length occupied by the DMRS port is 2, the terminal device may determine the DMRS port allocated to the terminal device by the access network device based on Table 6A or Table 6B and the index value indicated by the indication information 3. For whether the terminal device specifically uses Table 6A or Table 6B, please refer to the above description of whether the terminal device uses Table 3A or Table 3B.

[0142] [Table 9] TIFF2025515309000019.tif250170 TIFF2025515309000020.tif52170

[0143] [Table 10] TIFF2025515309000022.tif193128 TIFF2025515309000023.tif46170

[0144] The case of one codeword in Table 6A is used as an example. For example, when the index value indicated by the indication information 3 is “1”, the DMRS port index associated with the index value “1” in Table 6 is 1, and the symbol length occupied by the DMRS port associated with the index value “1” in Table 6 is 1, so that the terminal device can determine that the DMRS port allocated to the terminal device by the access network device is DMRS port 1 among DMRS ports 0 to 5 corresponding to the single-symbol DMRS of Type 2. In another example, when the index value indicated by the indication information 3 is “25”, the DMRS port index associated with the index value “25” in Table 6 is 1, and the symbol length occupied by the DMRS port associated with the index value “25” in Table 6 is 2, so that the terminal device can determine that the DMRS port allocated to the terminal device by the access network device is DMRS port 1 among DMRS ports 0 to DMRS ports 11 corresponding to the double-symbol DMRS of Type 2.

[0145] 6.DMRS port expansion

[0146] It can be seen from the above description that the maximum number of orthogonal DMRS ports supported by configuration type 1 is 8, and the maximum number of orthogonal DMRS ports supported by configuration type 2 is 12. When multiple parallel data streams are simultaneously transmitted on the same time-frequency resource, each data stream may be referred to as a spatial layer, a spatial stream, or a transmission stream, and one DMRS port may correspond to one spatial layer or a transmission stream. DMRS port indexes corresponding to the V spatial layers may be determined based on the sequence of DMRS port indexes in Tables 3A to 6B. For example, the V spatial layers include spatial layer 0 and spatial layer 1. If the DMRS port index assigned by the access network device to the terminal device is “0,1”, the spatial layer 0 corresponds to DMRS port 0, and the spatial layer 1 corresponds to DMRS port 1. If the DMRS port index assigned by the access network device to the terminal device is “2,3”, the spatial layer 0 corresponds to DMRS port 2, and the spatial layer 1 corresponds to DMRS port 3.

[0147] However, as wireless communication devices are deployed more densely and the number of terminal devices further increases, higher requirements are imposed on the number of MIMO transmission streams (more than 12 transmission streams). However, the maximum of 12 DMRS ports cannot ensure good transmission performance for more than 12 transmission streams. Therefore, it is necessary to extend the DMRS ports to support more transmission streams.

[0148] There may be several ways to extend the DMRS port. For example, the DMRS port may be extended by code division multiplexing, or the DMRS port may be extended by frequency division multiplexing. In the following, the relevant content of the DMRS port extension is described by using an example in which the DMRS port is extended through code division multiplexing.

[0149] (1) Explain the newly added DMRS port configuration type 1

[0150] A double-symbol DMRS of configuration type 1 is used as an example. DMRS port 0 to DMRS port 7 can be referred to as existing DMRS ports, and DMRS port 8 to DMRS port 15 are extended DMRS ports and can be referred to as newly added DMRS ports. The time-frequency resource corresponding to the existing DMRS port and the time-frequency resource corresponding to the newly added DMRS port are the same. Hereinafter, a description is provided with reference to FIG. 4. In FIG. 4, the vertical direction represents the frequency domain, the horizontal direction represents the time domain, one grid represents one RE, and one RE corresponds to one subcarrier in the frequency domain and corresponds to one time domain symbol in the time domain. In addition, the time-frequency resource corresponding to the existing DMRS port and the time-frequency resource corresponding to the newly added DMRS port are the same. Therefore, the multiple REs shown in (1) and the multiple REs shown in (2) in FIG. 4 may be the same RE. In FIG. 4, the existing DMRS port and the newly added DMRS port are shown separately for ease of explanation. FIG. 4 shows only the case of one RB. For the multiple RB case, see FIG.

[0151] In the existing DMRS port, as mentioned above, one CDM group includes four DMRS ports that are mapped to two subcarriers and two time domain symbols (i.e., four REs). One CDM group is taken as an example, as shown in (1) in FIG. 4. The CDM group corresponds to the existing DMRS port 0, DMRS port 1, DMRS port 4, and DMRS port 5, and occupies subcarriers whose indices are 0 / 2 / 4 / 6 / 8 / 10 in one RB. The four DMRS ports in the CDM group can be code division multiplexed by using an inner cover code sequence whose length is four. Specifically, each DMRS port can correspond to an inner frequency domain cover code sequence whose length is two and an inner time domain cover code sequence whose length is two. That is, each DMRS port can correspond to an inner cover code sequence whose length is four (denoted as (w1, w2, w3, w4)), and there is a one-to-one correspondence between the elements in each inner cover code sequence and the four REs. An inner cover code sequence, whose length is four, may be formed by the Kronecker product of the corresponding inner frequency-domain cover code sequence and the inner time-domain cover code sequence. The inner cover code sequences corresponding to any two of the four DMRS ports of a CDM group are orthogonal.

[0152] For example, the inner cover code sequence (w1, w2, w3, w4) corresponding to DMRS port 0 may be (+1+1+1+1), the inner cover code sequence (w1, w2, w3, w4) corresponding to DMRS port 1 may be (+1+1-1-1), the inner cover code sequence (w1, w2, w3, w4) corresponding to DMRS port 4 may be (+1-1+1-1), and the inner cover code sequence (w1, w2, w3, w4) corresponding to DMRS port 5 may be (+1-1-1+1).

[0153] Also, the newly added DMRS port can correspond to two CDM groups, and each CDM group corresponds to four DMRS ports. One CDM group corresponds to four DMRS ports that are mapped to two subcarriers and two time domain symbols (i.e., four REs). One CDM group is used as an example, as shown in (2) in FIG. 4. The CDM groups correspond to the newly added DMRS port 8, DMRS port 9, DMRS port 12, and DMRS port 13, and occupy subcarriers whose indices are 0 / 2 / 4 / 6 / 8 / 10 in one RB. The four DMRS ports in the CDM group can be code division multiplexed by using an inner cover code sequence whose length is four. Specifically, each DMRS port can correspond to an inner frequency domain cover code sequence whose length is two and an inner time domain cover code sequence whose length is two. That is, each DMRS port may correspond to an inner cover code sequence whose length is four (denoted as (c1, c2, c3, c4)), and there is a one-to-one correspondence between elements in each inner cover code sequence and the four REs. The inner cover code sequence whose length is four may be formed by the Kronecker product of the corresponding inner frequency domain cover code sequence and the inner time domain cover code sequence. The inner cover code sequences corresponding to any two of the four DMRS ports of a CDM group are orthogonal. Two possible implementations of the inner cover code sequences are described below with reference to examples a1 and a2.

[0154] Example a1: The inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 8 can be (+1, +1, +1, +1), the inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 9 can be (+1, +1, -1, -1), the inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 12 can be (+1, -1, +1, -1), and the inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 13 can be (+1, -1, -1, +1).

[0155] Example a2: The inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 8 can be (+1, +j, +j, -1), the inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 9 can be (+1, +j, -j, +1), the inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 12 can be (+1, -j, +j, +1), and the inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 13 can be (+1, -j, -j, -1).

[0156] Furthermore, for four consecutive subcarriers (the four subcarriers may be referred to as a group of subcarriers) mapped to a DMRS port, four existing DMRS ports (e.g., DMRS Port 0, DMRS Port 1, DMRS Port 4, and DMRS Port 5) and four newly added DMRS ports (e.g., DMRS Port 8, DMRS Port 9, DMRS Port 12, and DMRS Port 13) may be code division multiplexed by using an outer cover code sequence (b1, b2, b3, b4) whose length is 4. For example, for subcarrier 0, subcarrier 2, subcarrier 4, and subcarrier 6, four existing DMRS ports (e.g., DMRS Port 0, DMRS Port 1, DMRS Port 4, and DMRS Port 5) and four newly added DMRS ports (e.g., DMRS Port 8, DMRS Port 9, DMRS Port 12, and DMRS Port 13) may be code division multiplexed by using an outer cover code sequence (b1, b2, b3, b4) whose length is 4. The outer cover code sequence (b1, b2, b3, b4) corresponding to the four existing DMRS ports is, for example, (+1, +1, +1, +1), and the outer cover code sequence (b1, b2, b3, b4) corresponding to the four newly added DMRS ports is, for example, (+1, +1, -1, -1). The two outer cover code sequences are orthogonal. One element in the outer cover code sequence (b1, b2, b3, b4) corresponds to one subcarrier in the group of subcarriers. For example, subcarrier 0 corresponds to sequence element b1, subcarrier 2 corresponds to sequence element b2, subcarrier 4 corresponds to sequence element b3, and subcarrier 6 corresponds to sequence element b4.

[0157] (2) Explain the newly added DMRS port configuration type 2

[0158] A double-symbol DMRS of configuration type 2 is used as an example. DMRS port 0 to DMRS port 11 can be referred to as existing DMRS ports, and DMRS port 12 to DMRS port 23 are extended DMRS ports and can be referred to as newly added DMRS ports. The time-frequency resources corresponding to the existing DMRS ports and the time-frequency resources corresponding to the newly added DMRS ports are the same. Hereinafter, a description is provided with reference to FIG. 5. In FIG. 5, the multiple REs shown in (1) and the multiple REs shown in (2) may be the same REs. For other cases, please refer to the description in FIG. 4.

[0159] In the existing DMRS port, as mentioned above, one CDM group includes four DMRS ports that are mapped to two subcarriers and two time domain symbols (i.e., four REs). One CDM group is taken as an example, as shown in (1) in FIG. 5. The CDM group corresponds to the existing DMRS port 0, DMRS port 1, DMRS port 6, and DMRS port 7, and occupies subcarriers whose indices are 0 / 1 / 6 / 7 in one RB. The four DMRS ports in the CDM group can be code division multiplexed by using an inner cover code sequence whose length is four. Specifically, each DMRS port can correspond to an inner frequency domain cover code sequence whose length is two and an inner time domain cover code sequence whose length is two. That is, each DMRS port can correspond to an inner cover code sequence whose length is four (denoted as (w1, w2, w3, w4)), and there is a one-to-one correspondence between the elements in each inner cover code sequence and the four REs. An inner cover code sequence, whose length is four, may be formed by the Kronecker product of the corresponding inner frequency-domain cover code sequence and the inner time-domain cover code sequence. The inner cover code sequences corresponding to any two of the four DMRS ports of a CDM group are orthogonal.

[0160] For example, the inner cover code sequence (w1, w2, w3, w4) corresponding to DMRS port 0 may be (+1, +1, +1, +1), the inner cover code sequence (w1, w2, w3, w4) corresponding to DMRS port 1 may be (+1, +1, -1, -1), the inner cover code sequence (w1, w2, w3, w4) corresponding to DMRS port 6 may be (+1, -1, +1, -1), and the inner cover code sequence (w1, w2, w3, w4) corresponding to DMRS port 7 may be (+1, -1, -1, +1).

[0161] Also, the newly added DMRS port can correspond to two CDM groups, and each CDM group corresponds to four DMRS ports. One CDM group corresponds to four DMRS ports that are mapped to two subcarriers and two time domain symbols (i.e., four REs). One CDM group is used as an example, as shown in (2) in FIG. 5. The CDM group corresponds to the newly added DMRS port 12, DMRS port 13, DMRS port 18, and DMRS port 19, and occupies subcarriers whose indices are 0 / 1 / 6 / 7 in one RB. The four DMRS ports in the CDM group can be code division multiplexed by using an inner cover code sequence whose length is four. Specifically, each DMRS port can correspond to an inner frequency domain cover code sequence whose length is two and an inner time domain cover code sequence whose length is two. That is, each DMRS port may correspond to an inner cover code sequence whose length is four (denoted as (c1, c2, c3, c4)), and there is a one-to-one correspondence between elements in each inner cover code sequence and the four REs. The inner cover code sequence whose length is four may be formed by the Kronecker product of the corresponding inner frequency domain cover code sequence and the inner time domain cover code sequence. The inner cover code sequences corresponding to any two of the four DMRS ports of a CDM group are orthogonal. Two possible implementations of the inner cover code sequences are described below with reference to examples b1 and b2.

[0162] Example b1: The inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 12 can be (+1, +1, +1, +1), the inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 13 can be (+1, +1, -1, -1), the inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 18 can be (+1, -1, +1, -1), and the inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 19 can be (+1, -1, -1, +1).

[0163] Example b2: The inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 12 can be (+1, +j, +j, -1), the inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 13 can be (+1, +j, -j, +1), the inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 18 can be (+1, -j, +j, +1), and the inner cover code sequence (c1, c2, c3, c4) corresponding to DMRS port 19 can be (+1, -j, -j, -1).

[0164] Furthermore, for four consecutive subcarriers (the four subcarriers are sometimes referred to as a group of subcarriers) mapped to a DMRS port, the four existing DMRS ports (e.g., DMRS Port 0, DMRS Port 1, DMRS Port 6, and DMRS Port 7) and the four newly added DMRS ports (e.g., DMRS Port 12, DMRS Port 13, DMRS Port 18, and DMRS Port 19) may be code division multiplexed by using an outer cover code sequence (b1, b2, b3, b4) whose length is four. For example, for subcarrier 0, subcarrier 1, subcarrier 6, and subcarrier 7, four existing DMRS ports (e.g., DMRS Port 0, DMRS Port 1, DMRS Port 6, and DMRS Port 7) and four newly added DMRS ports (e.g., DMRS Port 12, DMRS Port 13, DMRS Port 18, and DMRS Port 19) can be code division multiplexed by using an outer cover code sequence (b1, b2, b3, b4) whose length is 4. The outer cover code sequence (b1, b2, b3, b4) corresponding to the four existing DMRS ports is, for example, (+1, +1, +1, +1), and the outer cover code sequence (b1, b2, b3, b4) corresponding to the four newly added DMRS ports is, for example, (+1, +1, -1, -1). The two outer cover code sequences are orthogonal. One element in the outer cover code sequence (b1, b2, b3, b4) corresponds to one subcarrier in the group of subcarriers. For example, subcarrier 0 corresponds to sequence element b1, subcarrier 1 corresponds to sequence element b2, subcarrier 6 corresponds to sequence element b3, and subcarrier 7 corresponds to sequence element b4.

[0165] Based on the above descriptions in (1) and (2), after the DMRS ports are extended in a code division multiplexing manner, as shown in Table 7, a single-symbol DMRS of configuration type 1 can support up to 8 ports, a double-symbol DMRS of configuration type 1 can support up to 16 ports, a single-symbol DMRS of configuration type 2 can support up to 12 ports, and a double-symbol DMRS of configuration type 2 can support up to 24 ports.

[0166] [Table 11]

[0167] (3) Time-frequency resource mapping rules after DMRS port expansion

[0168] The DMRS sequences corresponding to the existing DMRS ports may be multiplied with the corresponding inner cover code sequences and outer cover code sequences and then mapped to the corresponding time-frequency resources according to the time-frequency resource mapping rule. The DMRS sequences corresponding to the newly added DMRS ports may be multiplied with the corresponding inner cover code sequences and outer cover code sequences and then mapped to the corresponding time-frequency resources according to the time-frequency resource mapping rule.

[0169] Therefore, after DMRS port extension, the time-frequency resource mapping rule is as follows:

[0170]

number

[0171] p is the DMRS port index, μ is the subcarrier spacing parameter,

[0172]

number

[0173]

number

[0174]

number

[0175] It can be understood that, referring to the form of Equation 1, Equation 2 can be equivalently expressed as the following Equation 3:

[0176]

number

[0177] s f(k') is the frequency domain cover code sequence element corresponding to the subcarrier whose index is k', and s f (l') is the time-domain cover code sequence element corresponding to the time-domain symbol whose index is l'.

[0178] It can be seen from Equation 3 that after the DMRS port extension, the frequency domain cover code sequence corresponding to each DMRS port is equivalent to the inner frequency domain cover code sequence c f The outer cover code sequence element b(0) corresponds to two adjacent subcarriers in the group of subcarriers occupied by the DMRS port. Specifically, the outer cover code sequence element b(0) corresponds to c f (0) and c f Similarly, the outer cover code sequence element b(1) corresponds to the other two adjacent subcarriers in the group of subcarriers occupied by the DMRS port. Specifically, the outer cover code sequence element b(1) corresponds to c f (0) and c f (1). Therefore, the length of the frequency domain cover code sequence corresponding to each DMRS port is 4, and (c f (0)b(0),c f (1)b(0),c f (0)b(1),c f (1)b(1)). However, if the DMRS ports are not extended (see above), the length of the frequency domain cover code sequence corresponding to each DMRS port is 2.

[0179] In addition, in Equation 2 or Equation 3, c corresponding to DMRS port p f (k'), c t The values ​​of (l') and Δ relate to the DMRS configuration type, see the following explanations in (3.1) and (3.2) for details.

[0180] (3.1) Configuration Type 1

[0181] In configuration type 1, c corresponding to DMRS port p f (k'), c t The values ​​of (l') and Δ can be determined according to Table 8A or Table 8B below. When the inner cover code sequence described in Example a1 above is used, c f (k'), c t The values ​​of (l') and Δ can be determined according to Table 8A. When the inner cover code sequence described in Example a2 above is used, c f (k'), c t The values ​​of (l') and Δ can be determined according to Table 8B.

[0182] [Table 12]

[0183] [Table 13]

[0184] (3.2) Configuration Type 2

[0185] In configuration type 2, c corresponding to DMRS port p f (k'), c t The values ​​of (l') and Δ can be determined according to Table 9A or Table 9B below. If the inner cover code sequence described in Example b1 above is used, then c f (k'), c t The values ​​of (l') and Δ can be determined according to Table 9A. If the inner cover code sequence described in Example b2 above is used, then c f (k'), c t The values ​​of (l') and Δ can be determined according to Table 9B.

[0186] [Table 14]

[0187] [Table 15]

[0188] Based on the above description of the related technical features, the embodiment of this application considers how the access network device indicates to the terminal device the DMRS port allocated to the terminal device after the DMRS port extension.

[0189] Before describing the communication method provided in the embodiment of this application, related concepts in the embodiment of this application will be described first.

[0190] DMRS port index group: One DMRS port index group may include one or more DMRS port indexes, and one DMRS port index group may be associated with one index value.

[0191] Set: A set may include one or more DMRS port index groups. For example, a set may include N DMRS port index groups. If each of the N DMRS port index groups includes at least one of the M DMRS port indexes, the M DMRS port indexes may be considered to correspond to a set. M and N are positive integers.

[0192] Association relationship: Two DMRS port index groups (eg, a first DMRS port index group and a second DMRS port index group) belonging to different sets can have an association relationship.

[0193] In one possible implementation, the association relationship between the first DMRS port index group and the second DMRS port index group may include one or more of the following.

[0194] (a) The first DMRS port index group and the second DMRS port index group are associated with the same index value.

[0195] (b) There is a one-to-one correspondence between the DMRS port indexes in the first DMRS port index group and the DMRS port indexes in the second DMRS port index group, for example, there may be an offset between two corresponding DMRS port indexes.

[0196] (c) the first DMRS port index group is a subset of the second DMRS port index group. For example, the second DMRS port index group may include a port index in the first DMRS port index group and may further include a DMRS port index corresponding to the DMRS port index in the first DMRS port index group. For example, the first DMRS port index group may include a first DMRS port index, and there is an offset between the DMRS port index corresponding to the first DMRS port index and the first DMRS port index.

[0197] In the embodiment of this application, an example in which the association relationship between the first DMRS port index group and the second DMRS port index group is the first association relationship or the second association relationship is used for explanation. The first DMRS port index group and the second DMRS port index group having the first association relationship may include (a) and (b), and the first DMRS port index group and the second DMRS port index group having the second association relationship may include (a) and (c).

[0198] The following describes in detail the sets and DMRS port index groups for different configuration types based on the first association relationship and the second association relationship.

[0199] 1. First association relationship

[0200] (1) Single-symbol DMRS with configuration type 1

[0201] For four existing DMRS port indexes (i.e., “0 to 3”) corresponding to single-symbol DMRS of configuration type 1, Table 3A is used as an example (for Table 3B, please refer to Table 3A). The four DMRS port indexes correspond to set 1, and set 1 can include 12 DMRS port index groups associated with index values ​​“0 to 11” in Table 3A. Each DMRS port index group includes one or more DMRS port indexes. For example, the DMRS port indexes included in the DMRS port index group associated with index value “2” are “0” and “1”. The correspondence between the four DMRS port indexes and set 1 can also be understood as set 1 including 12 DMRS port index groups. The DMRS port indexes included in any DMRS port index group are one or more DMRS port indexes among the four DMRS port indexes.

[0202] For four newly added DMRS port indexes (i.e., “4 to 7”) corresponding to single-symbol DMRS of configuration type 1, Table 10A is used as an example (for Table 10B, please refer to Table 10A). The four DMRS port indexes correspond to set 2, and set 2 can include 12 DMRS port index groups associated with index values ​​“0 to 11” in Table 10A. The DMRS port index groups included in set 2 and the DMRS port index groups included in set 1 have a first association relationship.

[0203] [Table 16]

[0204] [Table 17]

[0205] Table 10A corresponds to Table 3A, and Table 10B corresponds to Table 3B. Using Table 10A and Table 3A as an example. For example, set 1 includes DMRS port index group a1, where DMRS port index group a1 is any one of the 12 DMRS port index groups shown in Table 3A. Set 2 includes DMRS port index group b1, where DMRS port index group b1 is any one of the 12 DMRS port index groups shown in Table 10A. DMRS port index group a1 and DMRS port index group b1 have a first association relationship. Specifically, DMRS port index group a1 and DMRS port index group b1 are associated with the same index value, and there is a one-to-one correspondence between the DMRS port index in DMRS port index group a1 and the DMRS port index in DMRS port index group b1, and there is an offset between the corresponding DMRS port indexes.

[0206] The value of the offset may be determined based on the configuration type and the symbol length occupied by the DMRS port. If the configuration type is configuration type 1 and the symbol length occupied by the DMRS port is 1, the value of the offset may be 4. That is, the value of the offset may be equal to the number of DMRS port indexes corresponding to set 1, or the value of the offset may be equal to the maximum number of orthogonal DMRS ports supported by a single-symbol DMRS of configuration type 1.

[0207] For example, the DMRS port index included in DMRS port index group a1 associated with index value "0" in Table 3A is "0", the DMRS port index included in DMRS port index group b1 associated with index value "0" in Table 10A is "4", and the offset between DMRS port indices "0" and "4" is 4.

[0208] In another example, the DMRS port indexes included in DMRS port index group a1 associated with index value "2" in Table 3A are "0" and "1", and the DMRS port indexes included in DMRS port index group b1 associated with index value "2" in Table 10A are "4" and "5". DMRS port index "0" corresponds to DMRS port index "4", and the offset between the two DMRS port indexes is 4. DMRS port index "1" corresponds to DMRS port index "5", and the offset between the two DMRS port indexes is 4.

[0209] (2) Double-symbol DMRS of configuration type 1

[0210] For eight existing DMRS port indexes (i.e., “0-7”) corresponding to double-symbol DMRS of configuration type 1, the case of one codeword in Table 4A is used as an example (for Table 4B, see Table 4A). The eight DMRS port indexes correspond to Set 3, which includes 19 DMRS port index groups associated with index values ​​“12-30” in Table 4A.

[0211] For the eight newly added DMRS port indexes (i.e., “8 to 15”) corresponding to the double-symbol DMRS of configuration type 1, the case of one codeword in Table 11A is used as an example (for Table 11B, please refer to Table 11A). In the example of the case of one codeword, the eight DMRS port indexes correspond to set 4, and set 4 may include 19 DMRS port index groups associated with index values ​​“12 to 30” in Table 11A. The DMRS port index groups included in set 4 and the DMRS port index groups included in set 3 have a first association relationship.

[0212] [Table 18] TIFF2025515309000037.tif95170

[0213] [Table 19] TIFF2025515309000039.tif100170

[0214] Table 11A corresponds to Table 4A, and Table 11B corresponds to Table 4B. Table 11A and Table 4A are used as an example. Set 3 includes DMRS port index group a2, and DMRS port index group a2 is any one of the 19 DMRS port index groups shown in Table 4A. Set 4 includes DMRS port index group b2, and DMRS port index group b2 is any one of the 19 DMRS port index groups shown in Table 11A. DMRS port index group a2 and DMRS port index group b2 have a first association relationship. Specifically, DMRS port index group a2 and DMRS port index group b2 are associated with the same index value, and there is a one-to-one correspondence between the port index in DMRS port index group a2 and the port index in DMRS port index group b2, and there is an offset between the corresponding port indexes.

[0215] The value of the offset may be determined based on the configuration type and the symbol length occupied by the DMRS port. If the configuration type is configuration type 1 and the symbol length occupied by the DMRS port is 2, the value of the offset may be 8. That is, the value of the offset may be equal to the number of DMRS port indexes corresponding to set 3, or the value of the offset may be equal to the maximum number of orthogonal DMRS ports supported by the double-symbol DMRS of configuration type 1.

[0216] Using the case of one codeword as an example, for example, the DMRS port index included in DMRS port index group a2 associated with index value "12" in Table 4A is "0", the DMRS port index included in DMRS port index group b2 associated with index value "12" in Table 11A is "8", and the offset between DMRS port indexes "0" and "8" is 8.

[0217] In another example, the DMRS port indexes included in DMRS port index group a2 associated with index value "20" in Table 4A are "0" and "1", and the DMRS port indexes included in DMRS port index group b2 associated with index value "20" in Table 11A are "8" and "9". DMRS port index "0" corresponds to DMRS port index "8", and the offset between the two DMRS port indexes is 8. DMRS port index "1" corresponds to DMRS port index "9", and the offset between the two DMRS port indexes is 8.

[0218] (3) Single-symbol DMRS of configuration type 2

[0219] For six existing DMRS port indexes (i.e., “0-5”) corresponding to single-symbol DMRS of configuration type 2, the case of one codeword in Table 5A is used as an example (for Table 5B, see Table 5A). The five DMRS port indexes correspond to Set 5, which includes 24 DMRS port index groups associated with index values ​​“0-23” in Table 5A.

[0220] For six newly added DMRS port indexes (i.e., “6 to 11”) corresponding to single-symbol DMRS of configuration type 1, the case of one codeword in Table 12A is used as an example (for Table 12B, please refer to Table 12A). The six DMRS port indexes correspond to Set 6, which may include 24 DMRS port index groups associated with index values ​​“0 to 23” in Table 12A. The DMRS port index groups included in Set 6 and the DMRS port index groups included in Set 5 have a first association relationship.

[0221] [Table 20]

[0222] [Table 21]

[0223] Table 12A corresponds to Table 5A, and Table 12B corresponds to Table 5B. Table 12A and Table 5A are used as an example. Set 5 includes DMRS port index group a3, and DMRS port index group a3 is any one of the 24 DMRS port index groups shown in Table 5A. Set 6 includes DMRS port index group b3, and DMRS port index group b3 is any one of the 24 DMRS port index groups shown in Table 12A. DMRS port index group a3 and DMRS port index group b3 have a first association relationship. Specifically, DMRS port index group a3 and DMRS port index group b3 are associated with the same index value, and there is a one-to-one correspondence between the port index in DMRS port index group a3 and the port index in DMRS port index group b3, and there is an offset between the corresponding port indexes.

[0224] The value of the offset may be determined based on the configuration type and the symbol length occupied by the DMRS port. If the configuration type is configuration type 2 and the symbol length occupied by the DMRS port is 1, the value of the offset may be 6. That is, the value of the offset may be equal to the number of DMRS port indexes corresponding to set 5, or the value of the offset may be equal to the maximum number of orthogonal DMRS ports supported by a single-symbol DMRS of configuration type 2.

[0225] Using the case of one codeword as an example, for example, the DMRS port index included in DMRS port index group a3 associated with index value “0” in Table 5A is “0”, the DMRS port index included in DMRS port index group b3 associated with index value “0” in Table 12A is “6”, and the offset between DMRS port indexes “0” and “6” is 6.

[0226] In another example, the DMRS port indexes included in DMRS port index group a3 associated with index value "2" in Table 5A are "0" and "1", and the DMRS port indexes included in DMRS port index group b3 associated with index value "2" in Table 12A are "6" and "7". DMRS port index "0" corresponds to DMRS port index "6", and the offset between the two DMRS port indexes is 6. DMRS port index "1" corresponds to DMRS port index "7", and the offset between the two DMRS port indexes is 6.

[0227] (4) Double-symbol DMRS of configuration type 2

[0228] For the 12 existing DMRS port indexes (i.e., “0-11”) corresponding to the double-symbol DMRS of configuration type 2, the case of one codeword in Table 6A is used as an example (for Table 6B, see Table 6A). The 12 DMRS port indexes correspond to Set 7, which includes 34 DMRS port index groups associated with index values ​​“24-57” in Table 4A.

[0229] For eight newly added DMRS port indexes (i.e., “12 to 23”) corresponding to double-symbol DMRS of configuration type 2, the case of one codeword in Table 13A is used as an example (for Table 13B, please refer to Table 13A). The 12 DMRS port indexes correspond to Set 8, and Set 8 can include 34 DMRS port index groups associated with index values ​​“24 to 57” in Table 13A. The DMRS port index groups included in Set 8 and the DMRS port index groups included in Set 7 have a first association relationship.

[0230] [Table 22] TIFF2025515309000043.tif196128 TIFF2025515309000044.tif84170

[0231] [Table 23] TIFF2025515309000046.tif254170 TIFF2025515309000047.tif91170

[0232] Table 13A corresponds to Table 6A, and Table 13B corresponds to Table 6B. Using Table 13A and Table 6A as an example. Set 7 includes DMRS port index group a4, where DMRS port index group a4 is any one of the 34 DMRS port index groups shown in Table 6A. Set 8 includes DMRS port index group b4, where DMRS port index group b4 is any one of the 34 DMRS port index groups shown in Table 13A. DMRS port index group a4 and DMRS port index group b4 have a first association relationship. Specifically, DMRS port index group a4 and DMRS port index group b4 are associated with the same index value, and there is a one-to-one correspondence between the port index in DMRS port index group a4 and the port index in DMRS port index group b4, and there is an offset between the corresponding port indexes.

[0233] The value of the offset may be determined based on the configuration type and the symbol length occupied by the DMRS port. If the configuration type is configuration type 2 and the symbol length occupied by the DMRS port is 2, the value of the offset may be 12. That is, the value of the offset may be equal to the number of DMRS port indexes corresponding to set 7, or the value of the offset may be equal to the maximum number of orthogonal DMRS ports supported by the double-symbol DMRS of configuration type 2.

[0234] Using the case of one codeword as an example, for example, the DMRS port index included in DMRS port index group a4 associated with index value “24” in Table 6A is “0”, the DMRS port index included in DMRS port index group b4 associated with index value “24” in Table 13A is “12”, and the offset between the DMRS port indexes “0” and “12” is 12.

[0235] In another example, the DMRS port indexes included in DMRS port index group a4 associated with index value "36" in Table 6A are "0" and "1", and the DMRS port indexes included in DMRS port index group b4 associated with index value "36" in Table 13A are "12" and "13". DMRS port index "0" corresponds to DMRS port index "12", and the offset between the two DMRS port indexes is 12. DMRS port index "1" corresponds to DMRS port index "13", and the offset between the two DMRS port indexes is 12.

[0236] 2. Secondary Association Relationship

[0237] In the following, the case of single-symbol DMRS of configuration type 1 will be described. For other cases, please refer to the description here. The details will not be described again.

[0238] Table 3A is used as an example for four existing DMRS port indexes (i.e., “0-3”) corresponding to single-symbol DMRS of configuration type 1 (see Table 3A for Table 3B). The four DMRS port indexes correspond to Set 1, which may include 12 DMRS port index groups associated with index values ​​“0-11” in Table 3A.

[0239] After the DMRS port extension, the single-symbol DMRS of configuration type 1 can correspond to eight DMRS port indexes ("0-7", where "0-3" are the existing DMRS port indexes and "4-7" are the newly added DMRS port indexes). Table 14A is used as an example (for Table 14B, please refer to Table 14A). The eight DMRS port indexes correspond to set 2, and set 2 can include 12 DMRS port index groups associated with index values ​​"0-11" in Table 14A. The DMRS port index groups included in set 2 and the DMRS port index groups included in set 1 have a second association relationship.

[0240] [Table 24]

[0241] [Table 25]

[0242] Table 14A corresponds to Table 3A, and Table 14B corresponds to Table 3B. Table 14A and Table 3A are used as an example. For example, set 1 includes DMRS port index group a1, and DMRS port index group a1 is any one of the 12 DMRS port index groups shown in Table 3A. Set 2 includes DMRS port index group b1, and DMRS port index group b1 is any one of the 12 DMRS port index groups shown in Table 14A. DMRS port index group a1 and DMRS port index group b1 have a second association relationship. Specifically, DMRS port index group a1 and DMRS port index group b1 are associated with the same index value, and DMRS port index group a1 is a subset of DMRS port index group b1. DMRS port index group b1 includes DMRS port index group a1, and further includes a DMRS port index corresponding to the DMRS port index in DMRS port index group a1, and there is an offset between the two corresponding DMRS port indexes. The value of the offset may be determined based on the configuration type and the symbol length occupied by the DMRS port. If the configuration type is configuration type 1 and the symbol length occupied by the DMRS port is 1, the value of the offset may be 4.

[0243] For example, the DMRS port index included in DMRS port index group a1 associated with index value "0" in Table 3A is "0", the DMRS port index included in DMRS port index group b1 associated with index value "0" in Table 14A is "0" and "4", and the offset between DMRS port indices "0" and "4" is 4.

[0244] In another example, the DMRS port indexes included in DMRS port index group a1 associated with index value "2" in Table 3A are "0" and "1", and the DMRS port indexes included in DMRS port index group b1 associated with index value "2" in Table 14A are "0", "1", "4", and "5". DMRS port index "0" corresponds to DMRS port index "4", and the offset between the two DMRS port indexes is 4. DMRS port index "1" corresponds to DMRS port index "5", and the offset between the two DMRS port indexes is 4.

[0245] It can be understood that all tables in the embodiments of this application (eg, Table 1 to Table 14B) can be defined by a protocol.

[0246] Hereinafter, with reference to FIG. 6, a communication method in one embodiment of this application will be described.

[0247] 6 is a schematic flowchart corresponding to a communication method according to an embodiment of this application. As shown in FIG. 6, the method may include the following steps:

[0248] S601: An access network device sends first indication information to a terminal device. Correspondingly, the terminal device can receive the first indication information.

[0249] For example, the first indication may indicate a first index value, and the first index value may be associated with a first port index group in the first set of multiple port index groups and a second port index group in the second set of multiple port index groups, in other words, the first port index group and the second port index group are associated with the same index value.

[0250] For example, the first indication information may be carried in a MAC CE or a DCI. If the first indication information is carried in a DCI, a format used by the DCI may be, for example, DCI format 0_1, DCI format 0_2, DCI format 1_1, or DCI format 1_2.

[0251] S602: The access network device sends second indication information to the terminal device, where the second indication information indicates the first value or the second value. Correspondingly, the terminal device can receive the second indication information.

[0252] When the second indication information indicates a first value, the first indication information indicates a first port index group to the terminal device by using a first index value, in which case the port index assigned to the terminal device by the access network device is a port index in the first port index group. When the second indication information indicates a second value, the first indication information indicates a second port index group to the terminal device by using a first index value, in which case the port index assigned to the terminal device by the access network device is a port index in the second port index group.

[0253] Two possible implementations are described below with reference to Implementation 1 and Implementation 2.

[0254] (1) Implementation 1

[0255] In implementation 1, the second indication information may be carried in an RRC message. For example, the second indication information may be a dmrs-Type field in the RRC message. The first value indicates an existing DMRS port corresponding to configuration type 1, and the second value indicates a newly added DMRS port corresponding to configuration type 1. For example, the first value may be “type1”, and the second value may be “type1-E”. Alternatively, the first value may indicate an existing DMRS port corresponding to configuration type 2, and the second value may indicate a newly added DMRS port corresponding to configuration type 2. For example, the first value may be “type2”, and the second value may be “type2-E”. In other words, the second indication information may indicate any one of type 1, type 2, type 1-E, and type 2-E.

[0256] For example, the access network device may further send a fourth indication information to the terminal device. The fourth indication information indicates a maximum symbol length occupied by a reference signal (e.g., DMRS). For example, the maximum symbol length may be length 1 (len1) or length 2 (len2), where length 1 may be 1 symbol, and length 2 may be 2 symbols. The fourth indication information may be carried in an RRC message. For example, the fourth indication information may be a maxLength field in the RRC message. The fourth indication information and the second indication information may be carried in the same message, or may be carried in different messages. When the fourth indication information and the second indication information are carried in different messages, the order in which the access network device sends the different messages is not limited in this embodiment of this application.

[0257] For example, the fourth indication information and the second indication information are carried in the same RRC message. A possible signaling structure of the RRC message is shown below.

[0258] (outside 1) TIFF2025515309000050.tif72170

[0259] (2) Implementation 2

[0260] In implementation 2, the second indication information may be carried in a MAC CE or a DCI. The second indication information and the first indication information may be carried in the same message or in different messages. This is not limited. The first value indicates an existing DMRS port, and the second value indicates a newly added DMRS port. For example, the second indication information includes one bit. If the value of the bit is "0", the bit indicates an existing DMRS port. If the value of the bit is "1", the bit indicates a newly added DMRS port.

[0261] For example, the access network device may further transmit fourth indication information and fifth indication information to the terminal device. The fourth indication information indicates a maximum symbol length occupied by a reference signal (e.g., DMRS), and the fifth indication information indicates a configuration type of the reference signal (e.g., DMRS). For example, the fifth indication information may indicate "type 1" or "type 2". The fifth indication information may be carried in an RRC message. For example, the fifth indication information may be a dmrs-Type field in the RRC message. The fourth indication information and the fifth indication information may be carried in the same message or in different messages.

[0262] When the fourth indication information and the second indication information are carried in the same RRC message, a possible signaling structure of the RRC message is shown below.

[0263] (outside 2) TIFF2025515309000051.tif63170

[0264] Hereinafter, two possible cases based on the implementation 1 will be described by using an example in which the first port index group and the second port index group have a first association relationship.

[0265] Case 1: The second indication information indicates "Type 1" or "Type 1-E".

[0266] When the second indication information indicates a first value, for example, the second indication information indicates “Type 1”, the terminal device can determine based on the second indication information that the first indication information indicates a first port index group in the first set. When the second indication information indicates a second value, for example, the second indication information indicates “Type 1-E”, the terminal device can determine based on the second indication information that the first indication information indicates a second port index group in the second set.

[0267] (1) The maximum symbol length occupied by a DMRS port is 1.

[0268] When the maximum symbol length occupied by a DMRS port is 1, for example, if the first index value indicated by the first indication information is “2” and the second indication information indicates “Type 1”, the terminal device can determine, based on the second indication information, that the first indication information indicates a first port index group in a first set, and the port indexes included in the first port index group are “0” and “1”. If the second indication information indicates “Type 1-E”, the terminal device can determine, based on the second indication information, that the first indication information indicates a second port index group in a second set, and the port indexes included in the second port index group are “4” and “5”.

[0269] The terminal device may determine the port index group indicated by the first indication information in multiple manners, for example, manner 1 and manner 2.

[0270] (1.1) Method 1

[0271] The multiple port index groups included in the first set are shown in Table 3A and the multiple port index groups included in the second set are shown in Table 10A, or the multiple port index groups included in the first set are shown in Table 3B and the multiple port index groups included in the second set are shown in Table 10B.

[0272] When the second indication information indicates “Type 1”, the terminal device can determine that the table that needs to be looked up is Table 3A (here, Table 3A is used as an example, and for Table 3B, please refer to Table 3A). When the first index value indicated by the first indication information is “2”, the terminal device can determine, based on the first index value and Table 3A, that the first indication information indicates a first port index group, and the port indexes included in the first port index group are “0” and “1”.

[0273] When the second indication information indicates “Type 1-E”, the terminal device can determine that the table that needs to be looked up is table 10A (here, table 10A is used as an example, and for table 10B, please refer to table 10A). When the first index value indicated by the first indication information is “2”, the terminal device can determine, based on the first index value and table 10A, that the first indication information indicates a second port index group, and the port indexes included in the second port index group are “4” and “5”.

[0274] In the first method, after a newly added DMRS port is introduced, if the port allocated to the terminal device by the access network device is the newly added DMRS port, the port allocated to the terminal device by the access network device can be determined by referring to a table corresponding to the newly added DMRS port. The table corresponding to the newly added DMRS port can be designed by referring to a table corresponding to an existing DMRS port, so that the complexity of implementation can be effectively reduced.

[0275] (1.2) Method 2

[0276] The multiple port index groups included in the first set are shown in Table 3A or Table 3B, and the multiple port index groups included in the second set are obtained by using port indexes and offsets included in the multiple port index groups in the first port set.

[0277] When the second indication information indicates “Type 1”, the terminal device can determine that the table that needs to be looked up is Table 3A (here, Table 3A is used as an example, and for Table 3B, please refer to Table 3A). When the first index value indicated by the first indication information is “2”, the terminal device can determine, based on the first index value and Table 3A, that the first indication information indicates a first port index group, and the port indexes included in the first port index group are “0” and “1”.

[0278] When the second indication information indicates “Type 1-E” and the first index value indicated by the first indication information is “2”, the terminal device can determine a first port index group based on the first index value, and the port indexes included in the first port index group are “0” and “1”. Furthermore, since the first indication information indicates a second port index group in the second set, the terminal device obtains port indexes “4” and “5” in the second port index group based on the port indexes “0” and “1” in the first port index group and an offset (having a value of 4).

[0279] In method 2, after a newly added DMRS port is introduced, if the port assigned to the terminal device by the access network device is the newly added DMRS port, the table corresponding to the existing DMRS port can be reused, which effectively reduces the complexity of implementation.

[0280] (2) The maximum symbol length occupied by a DMRS port is 2.

[0281] When the maximum symbol length occupied by a DMRS port is 2, for example, if the first index value is “20” and the second indication information indicates “Type 1”, the terminal device can determine, based on the second indication information, that the first indication information indicates a first port index group in a first set, and the port indexes included in the first port index group are “0” and “1”. If the second indication information indicates “Type 1-E”, the terminal device can determine, based on the second indication information, that the first indication information indicates a second port index group in a second set, and the port indexes included in the second port index group are “4” and “5”.

[0282] The terminal device may determine the port index group indicated by the first indication information in multiple manners, for example, manner 1 and manner 2.

[0283] (2.1) Method 1

[0284] The multiple port index groups included in the first set are shown in Table 4A and the multiple port index groups included in the second set are shown in Table 11A, or the multiple port index groups included in the first set are shown in Table 4B and the multiple port index groups included in the second set are shown in Table 11B.

[0285] When the second indication information indicates “Type 1”, the terminal device can determine that the table that needs to be looked up is Table 4A (here, Table 4A is used as an example, and for Table 4B, please refer to Table 4A). When the first index value indicated by the first indication information is “20”, the terminal device can determine, based on the first index value and Table 4A, that the first indication information indicates a first port index group, and the port indexes included in the first port index group are “0” and “1”.

[0286] When the second indication information indicates “Type 1-E”, the terminal device can determine that the table that needs to be looked up is table 11A (here, table 11A is used as an example, and for table 11B, please refer to table 11A). When the first index value indicated by the first indication information is “20”, the terminal device can determine, based on the first index value and table 11A, that the first indication information indicates a second port index group, and the port indexes included in the second port index group are “8” and “9”.

[0287] (2.2) Method 2

[0288] The multiple port index groups included in the first set are shown in Table 4A or Table 4B, and the multiple port index groups included in the second set are obtained by using port indexes and offsets included in the multiple port index groups in the first port set.

[0289] When the second indication information indicates “Type 1”, the terminal device can determine that the table that needs to be looked up is Table 4A (here, Table 4A is used as an example, and for Table 4B, please refer to Table 4A). When the first index value indicated by the first indication information is “2”, the terminal device can determine, based on the first index value and Table 4A, that the first indication information indicates a first port index group, and the port indexes included in the first port index group are “0” and “1”.

[0290] When the second indication information indicates “Type 1-E” and the first index value indicated by the first indication information is “2”, the terminal device can determine a first port index group based on the first index value, and the port indexes included in the first port index group are “0” and “1”. Furthermore, since the second indication information indicates a second port index group in the second set, the terminal device obtains port indexes “8” and “9” in the second port index group based on the port indexes “0” and “1” in the first port index group and an offset (having a value of 8).

[0291] Case 2: The second indication information indicates "Type 2" or "Type 2-E".

[0292] When the second indication information indicates a first value, for example, the second indication information indicates “Type 2”, the terminal device can determine based on the second indication information that the first indication information indicates a first port index group in the first set. When the second indication information indicates a second value, for example, the second indication information indicates “Type 2-E”, the terminal device can determine based on the second indication information that the first indication information indicates a second port index group in the second set.

[0293] (1) The maximum symbol length occupied by a DMRS port is 1.

[0294] When the maximum symbol length occupied by a DMRS port is 1, for example, if the first index value indicated by the first indication information is “2” and the second indication information indicates “Type 2”, the terminal device can determine, based on the second indication information, that the first indication information indicates a first port index group in a first set, and the port indexes included in the first port index group are “0” and “1”. If the second indication information indicates “Type 2-E”, the terminal device can determine, based on the second indication information, that the first indication information indicates a second port index group in a second set, and the port indexes included in the second port index group are “6” and “7”.

[0295] The terminal device may determine the port index group indicated by the first indication information in multiple manners, for example, manner 1 and manner 2.

[0296] (1.1) Method 1

[0297] The multiple port index groups included in the first set are shown in Table 5A and the multiple port index groups included in the second set are shown in Table 12A, or the multiple port index groups included in the first set are shown in Table 5B and the multiple port index groups included in the second set are shown in Table 12B.

[0298] When the second indication information indicates “Type 2”, the terminal device can determine that the table that needs to be looked up is Table 5A (here, Table 5A is used as an example, and for Table 5B, please refer to Table 5A). When the first index value indicated by the first indication information is “2”, the terminal device can determine, based on the first index value and Table 5A, that the first indication information indicates a first port index group, and the port indexes included in the first port index group are “0” and “1”.

[0299] When the second indication information indicates “Type 2-E”, the terminal device can determine the table that needs to be looked up. For example, the table that needs to be looked up is table 12A (here, table 12A is used as an example, and for table 12B, please refer to table 12A). When the first index value indicated by the first indication information is “2”, the terminal device can determine based on the first index value and table 12A that the first indication information indicates a second port index group, and the port indexes included in the second port index group are “6” and “7”.

[0300] (1.2) Method 2

[0301] The multiple port index groups included in the first set are shown in Table 5A or Table 5B, and the multiple port index groups included in the second set are obtained by using port indexes and offsets included in the multiple port index groups in the first port set.

[0302] When the second indication information indicates “Type 2”, the terminal device can determine that the table that needs to be looked up is Table 5A (here, Table 5A is used as an example, and for Table 5B, please refer to Table 5A). When the first index value indicated by the first indication information is “2”, the terminal device can determine, based on the first index value and Table 5A, that the first indication information indicates a first port index group, and the port indexes included in the first port index group are “0” and “1”.

[0303] When the second indication information indicates “TYPE 2-E” and the first index value indicated by the first indication information is “2”, the terminal device can determine a first port index group based on the first index value, and the port indexes included in the first port index group are “0” and “1”. Furthermore, since the second indication information indicates a second port index group in the second set, the terminal device obtains port indexes “6” and “7” in the second port index group based on the port indexes “0” and “1” in the first port index group and an offset (having a value of 6).

[0304] (2) The maximum symbol length occupied by a DMRS port is 2.

[0305] When the maximum symbol length occupied by a DMRS port is 2, for example, if the first index value is “36” and the second indication information indicates “Type 2”, the terminal device can determine, based on the second indication information, that the first indication information indicates a first port index group in a first set, and the port indexes included in the first port index group are “0” and “1”. If the second indication information indicates “Type 2-E”, the terminal device can determine, based on the second indication information, that the first indication information indicates a second port index group in a second set, and the port indexes included in the second port index group are “12” and “13”.

[0306] The terminal device may determine the port index group indicated by the first indication information in multiple manners, for example, manner 1 and manner 2.

[0307] (2.1) Method 1

[0308] The multiple port index groups included in the first set are shown in Table 6A and the multiple port index groups included in the second set are shown in Table 13A, or the multiple port index groups included in the first set are shown in Table 6B and the multiple port index groups included in the second set are shown in Table 13B.

[0309] When the second indication information indicates “Type 2”, the terminal device can determine a table that needs to be looked up. For example, the table that needs to be looked up is table 6A. When the first index value indicated by the first indication information is “36”, the terminal device can determine, based on the first index value and table 6A, that the first indication information indicates a first port index group, and the port indexes included in the first port index group are “0” and “1”.

[0310] When the second indication information indicates “Type 2-E”, the terminal device can determine a table that needs to be looked up. For example, the table that needs to be looked up is table 13A. When the first index value indicated by the first indication information is “36”, the terminal device can determine, based on the first index value and table 13A, that the first indication information indicates a second port index group, and the port indexes included in the second port index group are “12” and “13”.

[0311] There may be multiple specific implementations in which the terminal device determines which table needs to be looked up. For example, the terminal device may determine which table needs to be looked up based on the configuration type, the symbol length occupied by the DMRS port, and other possible information.

[0312] (2.2) Method 2

[0313] The multiple port index groups included in the first set are shown in Table 6A or Table 6B, and the multiple port index groups included in the second set are obtained by using port indexes and offsets included in the multiple port index groups in the first port set.

[0314] When the second indication information indicates “Type 2”, the terminal device can determine a table that needs to be looked up. For example, the table that needs to be looked up is table 6A. When the first index value indicated by the first indication information is “36”, the terminal device can determine, based on the first index value and table 6A, that the first indication information indicates a first port index group, and the port indexes included in the first port index group are “0” and “1”.

[0315] When the second indication information indicates “TYPE 2-E” and the first index value indicated by the first indication information is “36”, the terminal device can determine a first port index group based on the first index value, and the port indexes included in the first port index group are “0” and “1”. Furthermore, since the second indication information indicates a second port index group in the second set, the terminal device obtains port indexes “12” and “13” in the second port index group based on the port indexes “0” and “1” in the first port index group and an offset (having a value of 12).

[0316] It can be understood that the above two cases are described using an example in which the association relationship between the first port index group and the second port index group is a first association relationship. When the association relationship between the first port index group and the second port index group is a second association relationship, reference can be made to the description herein.

[0317] It can be seen from the above description that the DMRS port indication method provided in this embodiment of the present application establishes an association relationship between the first port index group and the second port index group, so that the DMRS port index group indicated by the first indication information is interpreted differently for different values ​​indicated by the second indication information, so that after DMRS port extension, the indication overhead can be effectively reduced while indicating the DMRS port allocated to the terminal device.

[0318] In addition, when the association relationship between the first port index group and the second port index group is a first association relationship, all the port indexes in the first port index group can be existing DMRS port indexes, and all the port indexes in the second port index group can be newly added DMRS port indexes, so that the DMRS ports assigned to the terminal device by the access network device do not include both the existing DMRS ports and the newly added DMRS ports at the same time, which can better ensure channel estimation performance. The detailed description is as follows.

[0319] In general, after the DMRS port extension, the DMRS ports allocated to the terminal device by the access network device may be all existing ports, all newly added ports, or some existing ports and other some newly added ports. The double-symbol DMRS of configuration type 1 is used as an example. The DMRS port indexes allocated to the terminal device by the access network device may include at least one of 0, 1, 2, 3, 4, 5, 6, and 7, or may include at least one of 8, 9, 10, 11, 12, 13, 14, and 15, or may include at least one of 0, 1, 2, 3, 4, 5, 6, and 7 and at least one of 8, 9, 10, 11, 12, 13, 14, and 15. As shown in Table 4A, 8 DMRS port indexes (i.e., 0 to 7) correspond to 19 DMRS port index groups. After the newly added DMRS port is introduced, 16 DMRS port indexes (i.e., 0 to 16) correspond to more DMRS port index groups. Therefore, if the DMRS port indication method described in FIG. 3 is still used after the newly added DMRS port is introduced, multiple other possible DMRS port index groups need to be added to Table 3A to Table 6B. As a result, the implementation is relatively complicated. For example, after multiple other possible DMRS port index groups are added to Table 3A to Table 6B, the index value is correspondingly large (the value of the index value is large). As a result, the access network device needs to use more bits to indicate the index value to the terminal device, and the signaling overhead is high.

[0320] After analyzing this issue, the following was found:

[0321] DMRS symbols corresponding to existing DMRS ports (e.g., DMRS Port 0, DMRS Port 1, DMRS Port 4, and DMRS Port 5) and newly added DMRS ports (e.g., DMRS Port 8, DMRS Port 9, DMRS Port 12, and DMRS Port 13) are mapped to the same time-frequency resources. For existing DMRS ports, the orthogonality of the four DMRS ports is ensured by using (w1, w2, w3, w4). For newly added DMRS ports, the orthogonality of the four DMRS ports is ensured by using (c1, c2, c3, c4). Therefore, when the access network device allocates one or more DMRS ports from the existing DMRS ports to the terminal device, it achieves the same channel estimation effect as when the access network device allocates one or more DMRS ports from the newly added DMRS ports to the terminal device.

[0322] Also, orthogonality between any two of the existing DMRS ports is ensured by using the inner cover code sequence. Therefore, to ensure the orthogonality between two existing DMRS ports, the channels corresponding to the two subcarriers to which the inner cover code sequence is mapped need to be the same. Similarly, orthogonality between any two of the newly added DMRS ports is ensured by using the inner cover code sequence. Therefore, to ensure the orthogonality between two newly added DMRS ports, the channels corresponding to the two subcarriers to which the inner cover code sequence is mapped need to be the same. However, in addition, orthogonality between the existing DMRS port and the newly added DMRS port needs to be ensured by using the outer cover code sequence. Therefore, to ensure the orthogonality between the existing DMRS port and the newly added DMRS port, the channels corresponding to the four subcarriers (e.g., subcarrier 0, subcarrier 2, subcarrier 4, and subcarrier 6) to which the inner cover code sequences of two adjacent groups are mapped need to be the same.

[0323] However, as the channel delay spreads or the maximum delay becomes larger, the channel frequency selective fading becomes more prominent, and the channel coherence bandwidth is further reduced. As a result, it is more difficult to maintain the same channel corresponding to four subcarriers than to maintain the same channel corresponding to two subcarriers. Therefore, when the DMRS ports allocated to the terminal device by the access network device are all existing DMRS ports or all newly added DMRS ports, the performance is better than when some of the DMRS ports allocated to the terminal device by the access network device are existing DMRS ports and some are newly added DMRS ports.

[0324] Based on the above analysis, for a terminal device, if the access network device allocates at least one DMRS port from the existing DMRS ports to the terminal device or allocates at least one DMRS port from the newly added DMRS ports to the terminal device, and does not allocate the existing DMRS port and the newly added DMRS port to the terminal device at the same time, the channel estimation performance can be better ensured and the implementation complexity can be effectively reduced.

[0325] After the access network device indicates to the terminal device the DMRS port allocated to the terminal device using the method in S601 and S602, the terminal device can transmit a DMRS (i.e., uplink transmission) to the access network device on the time-frequency resource corresponding to the DMRS port, or can receive a DMRS (i.e., downlink transmission) from the access network device on the time-frequency resource corresponding to the DMRS port. Whether the terminal device performs uplink transmission or downlink transmission can be indicated by the access network device using other possible information, which is not limited in this embodiment of this application.

[0326] Optionally, when the terminal device receives a DMRS from the access network device on a time-frequency resource corresponding to a DMRS port, the method may further include:

[0327] S603: The access network device sends third indication information to the terminal device. In response, the terminal device receives the third indication information.

[0328] For example, the third indication information may be carried in a MAC CE or a DCI. The third indication information and the above-mentioned first indication information and / or second indication information may be carried in the same message (for example, the same MAC CE or the same DCI), or may be carried in different messages. This is not particularly limited. In other words, the access network device may transmit the first indication information, the second indication information, and the third indication information to the terminal device separately using three messages. Alternatively, the access network device may transmit the first indication information, the second indication information, and the third indication information to the terminal device using two messages. In this case, any two of the first indication information, the second indication information, and the third indication information may be carried in the same message. Alternatively, the access network device may transmit the first indication information, the second indication information, and the third indication information to the terminal device using one message.

[0329] Hereinafter, the third instruction information will be described separately for the first association relationship and the second association relationship.

[0330] (1) The association relationship between the first port index group and the second port index group is a first association relationship.

[0331] When the association relationship between the first port index group and the second port index group is a first association relationship, there are two possible implementations:

[0332] First implementation: When the first indication information indicates a first port index group, the third indication information may indicate whether a port index group in the second set is assigned to another terminal device on the time-frequency resources assigned to the terminal device, or when the first indication information indicates a second port index group, the third indication information may indicate whether a port index group in the first set is assigned to another terminal device on the time-frequency resources assigned to the terminal device.

[0333] For example, the first indication information indicates a first port index group. If the third indication information indicates that the port index group in the second set is assigned to another terminal device, it indicates that the access network device assigns one port index group in the second set to another terminal device, or the access network device assigns multiple port index groups in the second set to multiple other terminal devices, respectively. In other words, the access network device may send the third indication information to the terminal device when any port index group in the second set is assigned to another terminal device.

[0334] It can be understood that "the third indication information indicates whether the port index group in the second set is assigned to another terminal device on the time-frequency resource assigned to the terminal device" may be replaced with other possible expressions. For example, it may be replaced with "the third indication information indicates whether the port index group in the second set is assigned to another terminal device in the same transmission or scheduling", or it may be replaced with "the third indication information indicates that the length of the frequency domain cover code sequence corresponding to the DMRS port assigned to the terminal device is 2 or 4". For other similar descriptions, please refer to the description herein.

[0335] Second implementation: When the first indication information indicates a first port index group, the third indication information may indicate whether a second port index group is assigned to another terminal device on the time-frequency resources assigned to the terminal device, or when the first indication information indicates a second port index group, the third indication information may indicate whether the first port index group is assigned to another terminal device on the time-frequency resources assigned to the terminal device.

[0336] For example, the first indication information indicates a first port index group. Specifically, when allocating a second port index group in the second set to another terminal device, the access network device may send a third indication information to the terminal device. When allocating a port index group other than the second port index group in the second set to another terminal device, the access network device may not send the third indication information to the terminal device.

[0337] The following describes in detail the first implementation separately from the access network device side and the terminal device side.

[0338] From the Access Network Device Perspective

[0339] When the access network device assigns the first port index group to the terminal device and does not assign the port index group in the second set to another terminal device, the access network device may send third indication information to the terminal device, where the third indication information indicates that the port index group in the second set is not assigned to the other terminal device.

[0340] When the access network device assigns the first port index group to the terminal device and assigns the port index group in the second set to another terminal device, the access network device may perform operation 1 and / or operation 2. The access network device performing operation 1 may mean that the access network device sends third indication information to the terminal device. The third indication information indicates that the port index group in the second set is assigned to another terminal device. The access network device performing operation 2 may mean that the access network device cancels interference between the paired terminal devices through zero-forcing precoding based on channel information of the paired terminal devices (e.g., the terminal device and the other terminal device).

[0341] When multiple terminal devices schedule the same time domain resources (e.g., slots) and the same or partially the same frequency domain resources (e.g., Physical Resource Blocks (PRBs)), but the DMRS ports assigned to the multiple terminal devices by the access network device are different (e.g., the multiple terminal devices include two terminal devices, and the access network device assigns an existing DMRS port to one of the terminal devices and a newly added DMRS port to the other of the terminal devices), the multiple terminal devices may be referred to as a group of paired terminal devices.

[0342] From the perspective of the terminal device

[0343] The terminal device may determine the port index assigned to the terminal device by the access network device as described above. For example, the access network device assigns a first port index group in a first set to the terminal device, the first set being set 3, and the port index included in the first port index group being DMRS port index “0”.

[0344] If the third indication indicates that the port index group in the second set is not assigned to another terminal device, no interference of the newly added DMRS port to the existing DMRS port occurs. Therefore, the DMRS ports assigned to the terminal device by the access network device are orthogonal without considering the outer cover code. In addition, when performing channel estimation based on the DMRS corresponding to DMRS port 0, the terminal device may not need to consider the influence of the outer cover code, that is, in other words, when performing channel estimation based on the DMRS corresponding to DMRS port 0, the terminal device may perform channel estimation based on a granularity of the frequency domain cover code length of 2, that is, in other words, when performing channel estimation based on the DMRS corresponding to DMRS port 0, the terminal device only needs to consider the despreading of the inner cover code.

[0345] If the third indication information indicates that the DMRS port index group in the second set is assigned to another terminal device, when only the inner cover code is considered, interference of the newly added DMRS port to the existing DMRS port occurs. Therefore, when performing channel estimation based on the DMRS corresponding to DMRS port 0, the terminal device needs to consider the influence of the outer cover code to reduce the interference of the newly added DMRS port to the existing DMRS port, that is, in other words, when performing channel estimation based on the DMRS corresponding to DMRS port 0, the terminal device needs to perform channel estimation based on a granularity of the frequency domain cover code length of 4, that is, in other words, when performing channel estimation based on the DMRS corresponding to DMRS port 0, the terminal device needs to consider despreading of the inner cover code and the outer cover code.

[0346] It can be understood that the above description of the access network device and the terminal device is only a possible example. For other cases in this embodiment of the application, please refer to the examples. For example, in some possible scenarios (e.g., the second port index group causes interference to the first port index group, and other port index groups other than the second port index group in the second set cause no interference or only small interference to the first port index group), "the port index group in the second set is not assigned to another terminal device" in the above example may be replaced with "the second port index group is not assigned to another terminal device". "The port index group in the second set is assigned to another terminal device" may be replaced with "the second port index group is assigned to another terminal device".

[0347] (2) The association relationship between the first port index group and the second port index group is a second association relationship.

[0348] When the association relationship between the first port index group and the second port index group is a second association relationship, when the first indication information indicates the first port index group, the third indication information may indicate whether a port index group in the second set is assigned to another terminal device on the time-frequency resources assigned to the terminal device, or when the first indication information indicates the second port index group, the third indication information may indicate whether a port index group in the first set is assigned to another terminal device on the time-frequency resources assigned to the terminal device.

[0349] For example, the first indication information indicates the first port index group. In other words, the access network device may send the third indication information to the terminal device when any of the port index groups in the second set is assigned to another terminal device.

[0350] It can be understood that when the association relationship between the first port index group and the second port index group is the second association relationship, if the first indication information indicates the first port index group, the DMRS port indexes in the first port index group are all existing DMRS port indexes (for example, the first port index group is the port index group shown in Tables 3A to 6B). In this case, the access network device may send the third indication information to the terminal device to indicate whether the port index groups in the second set are assigned to another terminal device. For specific implementation, please refer to the above description. When the access network device assigns the second port index group to the terminal device, the DMRS port indexes in the second port index group include the existing DMRS port indexes and the newly added DMRS port indexes (for example, the second port index group is the port index group shown in Tables 14A and 14B), so in this case, the terminal device can determine that the influence of the outer cover code needs to be considered in the channel estimation to reduce the interference between the newly added DMRS port and the existing DMRS port based on the assigned DMRS port index. Therefore, the access network device may not need to send the third indication information to the terminal device, and signaling overhead is reduced.

[0351] Also, S603 is an optional step. In other words, the access network device does not need to send the third indication information to the terminal device. In this case, the terminal device may perform channel estimation based on the granularity of the frequency domain cover code length of 4 by default.

[0352] According to the above method, the access network device can send third indication information to the terminal device, so that the terminal device can perform channel estimation in a corresponding manner based on the third indication information. For example, the terminal device does not need to consider despreading of the outer cover code in channel estimation based on the third indication information, so that the channel estimation is more conveniently performed. In another example, the terminal device can consider despreading of the inner cover code and the outer cover code in channel estimation based on the third indication information, so as to reduce interference between the existing DMRS port and the newly added DMRS port.

[0353] The above mainly describes the solutions provided in the embodiments of this application from the perspective of the interaction between communication devices. It can be understood that, in order to implement the above-mentioned functions, the access network device and the terminal device may include corresponding hardware structures and / or software modules for implementing the functions. Those skilled in the art should easily recognize that, in combination with the example units and algorithm steps described in the embodiments disclosed in this specification, the embodiments of this application may be implemented by hardware or a combination of hardware and computer software. Whether the functions are performed by hardware or by hardware driven by computer software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but the implementation should not be considered to go beyond the scope of this application.

[0354] In the embodiment of this application, the division into functional units may be performed for the access network device and the terminal device according to the above-mentioned method example. For example, each functional unit may be obtained through division based on the corresponding function, or two or more functions may be integrated into one unit. The integrated unit may be implemented in the form of hardware or in the form of a software functional unit.

[0355] When an integrated unit is used, FIG. 7 is a block diagram of a possible example of an apparatus according to an embodiment of this application. As shown in FIG. 7, the apparatus 700 may include a processing unit 702 and a communication unit 703. The processing unit 702 is configured to control and manage actions of the apparatus 700. The communication unit 703 is configured to support the apparatus 700 in communicating with another apparatus. Optionally, the communication unit 703 may include a receiving unit and / or a transmitting unit, also referred to as a transceiver unit, configured to perform receiving and transmitting operations, respectively. The apparatus 700 may further include a storage unit 701 configured to store program codes and / or data of the apparatus 700.

[0356] The apparatus 700 can be the access network device in the above-mentioned embodiment. The processing unit 702 can support the apparatus 700 in performing the actions of the access network device in the above-mentioned method example. Alternatively, the processing unit 702 can mainly perform the internal actions of the access network device in the method example, and the communication unit 703 can support the communication between the apparatus 700 and another device.

[0357] For example, in one embodiment, the communication unit 703 is configured to send first indication information to the terminal device and send second indication information to the terminal device. If the second indication information indicates a first value, the first indication information indicates a first port index group among the multiple port index groups included in the first set. If the second indication information indicates a second value, the first indication information indicates a second port index group among the multiple port index groups included in the second set. The first port index group and the second port index group have an association relationship.

[0358] The apparatus 700 may be the terminal device in the above-mentioned embodiment. The processing unit 702 can support the apparatus 700 in performing the actions of the terminal device in the above-mentioned method example. Alternatively, the processing unit 702 can mainly perform the internal actions of the terminal device in the method example, and the communication unit 703 can support the communication between the apparatus 700 and another device.

[0359] For example, in one embodiment, the communication unit 703 is configured to receive a first indication from the access network device and receive a second indication from the access network device. If the second indication indicates a first value, the first indication indicates a first port index group among the multiple port index groups included in the first set. If the second indication indicates a second value, the first indication indicates a second port index group among the multiple port index groups included in the second set. The first port index group and the second port index group have an association relationship.

[0360] It should be understood that the division into units in the above-mentioned device is merely a logical functional division. In actual implementation, all or some of the units may be integrated into one physical entity or may be physically separated. All units in the device may be realized in the form of software called by a processing element, or may be implemented in the form of hardware, or some units may be implemented in the form of software called by a processing element and some units may be implemented in the form of hardware. For example, each unit may be a processing element located separately, or may be integrated in a chip of the device for implementation. Each unit may instead be stored in a memory in the form of a program called by a processing element of the device to perform the function of the unit. All or some of the units may be integrated or implemented independently. The processing element here may also be referred to as a processor, and may be an integrated circuit having signal processing capabilities. In the implementation process, the above-mentioned method or the operations in the above-mentioned units may be implemented using a hardware integrated logic circuit in a processor element, or may be implemented in the form of a processing element calling software.

[0361] For example, the units of any of the above-mentioned devices may be one or more integrated circuits configured to implement the above-mentioned methods, such as one or more application specific integrated circuits (ASICs), one or more microprocessors (digital signal processors, DSPs), or one or more field programmable gate arrays (FPGAs), or a combination of at least two of these integrated circuit forms. In another example, the processing element may be a processor, such as a general-purpose central processing unit (CPU) or other processor that can call a program, if the units in the device may be implemented in a form in which the processing element schedules a program. In yet another example, the units may be integrated and implemented in a form of a system-on-a-chip (SoC).

[0362] The above-mentioned unit configured for receiving is an interface circuit of the device and is configured to receive a signal from another device. For example, if the device is implemented in the form of a chip, the receiving unit is an interface circuit of the chip configured to receive a signal from another chip or device. The above-mentioned unit configured for transmitting is an interface circuit of the device and is configured to transmit a signal to another device. For example, if the device is implemented in the form of a chip, the transmitting unit is an interface circuit of the chip configured to transmit a signal to another chip or device.

[0363] FIG. 8 is a diagram of the configuration of an access network device according to an embodiment of this application. The access network device (or base station) can be used in the communication system shown in FIG. 1 to perform the functions of the access network device in the above-mentioned method embodiment. As shown in FIG. 8, the access network device 80 may include one or more DUs 801 and one or more CUs 802. The DU 801 may include at least one antenna 8011, at least one radio frequency unit 8012, at least one processor 8013, and at least one memory 8014. The DU 801 is mainly configured to receive / transmit radio frequency signals, perform conversion between radio frequency signals and baseband signals, and perform partial baseband processing. The CU 802 may include at least one processor 8022 and at least one memory 8021.

[0364] The CU 802 is mainly configured to perform baseband processing, control the access network device, and the like. The DU 801 and the CU 802 may be physically co-located or physically separate, i.e., distributed base stations. The CU 802 is the control center of the access network device, and may also be referred to as a processing unit, and is mainly configured to complete baseband processing functions. For example, the CU 802 may be configured to control the access network device to perform operation procedures related to the access network device in the above-mentioned method embodiments.

[0365] Also, optionally, the access network device 80 may include one or more radio frequency units, one or more DUs, and one or more CUs. The DU may include at least one processor 8013 and at least one memory 8014, the radio frequency unit may include at least one antenna 8011 and at least one radio frequency unit 8012, and the CU may include at least one processor 8022 and at least one memory 8021.

[0366] In one example, the CU 802 may include one or more boards. The multiple boards may jointly support a radio access network (e.g., a 5G network) with a single access instruction, or may separately support radio access networks of different access standards (e.g., an LTE network, a 5G network, or other networks). The memory 8021 and the processor 8022 may serve the one or more boards. In other words, the memory and the processor may be disposed on each board. Alternatively, the multiple boards may share the same memory and the same processor. Also, the necessary circuits may be further disposed on each board. The DU 801 may include one or more boards. The multiple boards may jointly support a radio access network (e.g., a 5G network) with a single access instruction, or may separately support radio access networks of different access standards (e.g., an LTE network, a 5G network, or other networks). The memory 8014 and the processor 8013 may serve the one or more boards. In other words, the memory and the processor may be disposed on each board. Alternatively, multiple boards may share the same memory and the same processor, and further required circuitry may be placed on each board.

[0367] The access network device shown in Fig. 8 can implement all the processes related to the access network device in the above-mentioned method embodiments. The operations and / or functions of the modules in the access network device shown in Fig. 8 are intended to implement the corresponding procedures in the above-mentioned method embodiments. For details, please refer to the descriptions in the above-mentioned method embodiments. In order to avoid repetition, detailed descriptions will be omitted here as appropriate.

[0368] FIG. 9 is a diagram of a configuration of a terminal device according to an embodiment of this application. The terminal device can be used in the communication system shown in FIG. 1 to implement the operation of the terminal device in the above-mentioned embodiment. As shown in FIG. 9, the terminal device includes an antenna 910, a radio frequency unit 920, and a signal processing unit 930. The antenna 910 is connected to the radio frequency unit 920. In the downlink direction, the radio frequency unit 920 receives information transmitted by a network device (e.g., an access network device) through the antenna 910, and sends the information transmitted by the network device to the signal processing unit 930 for processing. In the uplink direction, the signal processing unit 930 processes the information of the terminal device and sends the information to the radio frequency unit 920. The radio frequency unit 920 processes the information of the terminal device and sends the processed information to a network device through the antenna 910.

[0369] The signal processing unit 930 may include a modem subsystem configured to process data at each communication protocol layer. The signal processing unit 930 may further include a central processing subsystem configured to process the operating system and application layers of the terminal device. The signal processing unit 930 may also include other subsystems, such as a multimedia subsystem or a peripheral subsystem. The multimedia subsystem is configured to control the camera, screen display, and the like of the terminal device. The peripheral subsystem is configured to connect to other devices. The modem subsystem may be a separately located chip.

[0370] The modem subsystem may include one or more processing elements 931, for example, one main control CPU and another integrated circuit. The modem subsystem may further include a memory element 932 and an interface circuit 933. The memory element 932 is configured to store data and programs. However, the programs used to execute the methods performed by the terminal device in the above-described methods may not be stored in the memory element 932, but may be stored in a memory external to the modem subsystem and loaded by the modem subsystem for use. The interface circuit 933 is configured to communicate with another subsystem.

[0371] The modem subsystem may be implemented by using a chip. The chip includes at least one processing element and an interface circuit. The processing element is configured to execute any method steps executed by the terminal device. The interface circuit is configured to communicate with another device. In one implementation, the unit of the terminal device that implements the steps of the above-mentioned method may be implemented by a program scheduled by the processing element. For example, an apparatus used in a terminal device includes a processing element and a storage element. The processing element calls the program stored in the storage element to execute the method executed by the terminal device in the above-mentioned method embodiment. The storage element may be a storage element located on the same chip as the processing element, i.e., an on-chip storage element.

[0372] In another implementation, the program for executing the method performed by the terminal device in the above-mentioned method embodiments may be in a storage element located on a different chip than the processing element, i.e., an off-chip storage element, in which case the processing element calls and executes the method performed by the terminal device in the above-mentioned method embodiments by calling or loading the program from the off-chip storage element into the on-chip storage element.

[0373] In yet another implementation, the unit of the terminal device implementing the steps of the method above may be configured as one or more processing elements, which are located in the modem subsystem. The processing elements here can be integrated circuits, for example one or more ASICs, one or more DSPs, one or more FPGAs, or a combination of these types of integrated circuits, which can be integrated together to form a chip.

[0374] The units of the terminal device implementing the steps of the above-mentioned method may be integrated together and implemented in the form of a SOC. The SOC chip is configured to implement the above-mentioned method. At least one processing element and a memory element may be integrated into a chip, and the processing element calls a program stored in the memory element to implement the above-mentioned method executed by the terminal device. Alternatively, at least one integrated circuit may be integrated into the chip to implement the above-mentioned method executed by the terminal device. Alternatively, with reference to the above-mentioned implementation, the functions of some units may be implemented by a program called by the processing element, and the functions of some units are implemented by the integrated circuit.

[0375] It can be seen that the above-mentioned apparatus used in the terminal device may include at least one processing element and an interface circuit, the at least one processing element being configured to execute any of the methods executed by the terminal device provided in the above-mentioned method embodiments. The processing element may execute some or all of the steps executed by the terminal device in a first manner, specifically by calling a program stored in a storage element, or may execute some or all of the steps executed by the terminal device in a second manner, specifically by using a hardware integrated logic circuit in the processor element in combination with an instruction, or may certainly execute some or all of the steps executed by the terminal device by combining the first manner and the second manner.

[0376] The processing element here may be the same as that described above and may be implemented using a processor. The functionality of the processing element may be the same as that of the processing unit described in FIG. 7. For example, the processing element may be a general-purpose processor, e.g., a CPU, or one or more integrated circuits configured to perform the above-described method, e.g., one or more ASICs, one or more microprocessors DSPs, or one or more FPGAs, or a combination of at least two of these integrated circuit forms. The storage element may be implemented using a memory, and the functionality of the storage element may be the same as that of the storage unit described in FIG. 7. The storage element may be one memory, or may be a collective term for multiple memories.

[0377] The terminal device shown in Fig. 9 can implement all the processes related to the terminal device in the above-mentioned method embodiments. The operations and / or functions of the modules in the terminal device shown in Fig. 9 are intended to implement the corresponding procedures in the above-mentioned method embodiments. For details, please refer to the descriptions in the above-mentioned method embodiments. In order to avoid repetition, detailed descriptions will be omitted here as appropriate.

[0378] The terms "system" and "network" may be used interchangeably in the embodiments of this application. "At least one" means one or more, and "multiple" means two or more. The term "and / or" describes an association relationship between associated objects and indicates that three relationships may exist. For example, A and / or B may indicate three cases: only A is present, both A and B are present, and only B is present, where A and B may be singular or plural. The character " / " generally indicates an "or" relationship between associated objects. At least one of the following items (multiple pieces) or similar expressions may indicate any combination of the items, including any combination of a single item (single piece) or multiple items (multiple pieces). For example, "at least one of A, B, and C" includes A, B, C, A and B, A and C, B and C, or A, B, and C. Additionally, unless otherwise specified, ordinal numbers, such as "first" and "second" in the embodiments of this application are used to distinguish between multiple objects and are not used to limit the order, chronology, priority, or importance of those multiple objects.

[0379] As should be understood by those skilled in the art, the embodiments of this application may be provided as a method, a system, or a computer program product. Thus, this application may take the form of a hardware-only embodiment, a software-only embodiment, or an embodiment having a combination of software and hardware. Furthermore, this application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk memory, optical memory, and the like) that contains computer-usable program code.

[0380] This application is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to this application. It should be understood that computer program instructions may be used to implement each step and / or each block in the flowcharts and / or block diagrams, and combinations of steps and / or blocks in the flowcharts and / or block diagrams. These computer program instructions may be provided to a processor of a general purpose computer, a special purpose computer, an embedded processor, or any other programmable data processing device to generate a machine, such that the instructions executed by the processor of the computer or any other programmable data processing device generate an apparatus that implements a particular function in one or more steps in the flowcharts and / or one or more blocks in the block diagrams.

[0381] These computer program instructions can be stored in a computer readable memory that can instruct a computer or any other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer readable memory produce intermediate products that include an instruction apparatus that implements a particular function in one or more steps in the flowcharts and / or one or more blocks in the block diagrams.

[0382] The computer program instructions may alternatively be loaded into a computer or other programmable data processing device to generate a computer-implemented process and cause a sequence of operations and steps to be executed on the computer or other programmable device. Thus, the instructions executed on the computer or other programmable device provide steps for implementing a particular function in one or more procedures in the flowcharts and / or one or more blocks in the block diagrams.

[0383] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application, and this application intends to cover such modifications and variations to this application as long as they fall within the scope of protection defined by the following claims and their equivalents.

Claims

1. 1. A communication method comprising: Sending first indication information to the terminal device; sending a second indication to the terminal device; having When the second indication indicates a first value, the first indication indicates a first port index group among a plurality of port index groups included in a first set; When the second indication indicates a second value, the first indication indicates a second port index group among a plurality of port index groups included in a second set; The first port index group and the second port index group have an association relationship. method.

2. The association relationship is a one-to-one correspondence exists between port indexes in the first port index group and port indexes in the second port index group. The method of claim 1,

3. 3. The method of claim 1, wherein there is an offset between the port indexes in the first port index group and the port indexes in the second port index group.

4. the first set corresponds to a plurality of port indexes, each of the plurality of port index groups included in the first set has at least one of the plurality of port indexes; the offset is equal to the number of port indexes corresponding to the first set; The method according to claim 3.

5. The method of claim 3 or 4, wherein the value of the offset is 4, 8, 6, or 12.

6. The association relationship is the first port index group is a subset of the second port index group; The method of claim 1,

7. The method according to claim 1 , wherein the second indication information is carried in a radio resource control (RRC) message or a downlink control information (DCI).

8. the first indication indicates a first index value; the first index value is associated with the first port index group and the second port index group; 8. The method according to any one of claims 1 to 7.

9. The first port index group and the second port index group correspond to the same time-frequency resource; the first port index group corresponds to a first cover code sequence, the second port index group corresponds to a second cover code sequence, and the first cover code sequence is orthogonal to the second cover code sequence.

9. The method according to any one of claims 1 to 8.

10. The method further comprises: sending a third indication to the terminal device; having When the first indication information indicates the first port index group, the third indication information indicates whether the second port index group is assigned to another terminal device on the time-frequency resource assigned to the terminal device; or If the first indication information indicates the second port index group, the third indication information indicates whether the first port index group is assigned to the other terminal device on the time-frequency resource assigned to the terminal device.

10. The method according to any one of claims 1 to 9.

11. 1. A communication method comprising: receiving a first indication from the access network device; receiving a second indication from the access network device; having When the second indication indicates a first value, the first indication indicates a first port index group among a plurality of port index groups included in a first set; When the second indication indicates a second value, the first indication indicates a second port index group among a plurality of port index groups included in a second set; The first port index group and the second port index group have an association relationship. method.

12. The association relationship is a one-to-one correspondence exists between port indexes in the first port index group and port indexes in the second port index group. The method according to claim 11, wherein

13. 13. The method of claim 11 or 12, wherein there is an offset between the port indexes in the first port index group and the port indexes in the second port index group.

14. the first set corresponds to a plurality of port indexes, each of the plurality of port index groups included in the first set has at least one of the plurality of port indexes; the offset is equal to the number of port indexes corresponding to the first set; The method of claim 13.

15. The method of claim 13 or 14, wherein the value of the offset is 4, 8, 6 or 12.

16. The association relationship is the first port index group is a subset of the second port index group; The method according to claim 11, wherein

17. The method according to claim 11 , wherein the second indication information is carried in an RRC message or a DCI.

18. the first indication indicates a first index value; the first index value is associated with the first port index group and the second port index group; 18. The method according to any one of claims 11 to 17.

19. The first port index group and the second port index group correspond to the same time-frequency resource; the first port index group corresponds to a first cover code sequence, the second port index group corresponds to a second cover code sequence, and the first cover code sequence is orthogonal to the second cover code sequence.

19. The method according to any one of claims 11 to 18.

20. The method further comprises: receiving a third indication from the access network device; having When the first indication information indicates the first port index group, the third indication information indicates whether the second port index group is assigned to another terminal device on the time-frequency resource assigned to the terminal device; or If the first indication information indicates the second port index group, the third indication information indicates whether the first port index group is assigned to the other terminal device on the time-frequency resource assigned to the terminal device.

20. The method of any one of claims 11 to 19.

21. 1. A communication device, comprising: a communication unit configured to transmit first indication information to a terminal device; having The communication unit is further configured to send second indication information to the terminal device; When the second indication indicates a first value, the first indication indicates a first port index group among a plurality of port index groups included in a first set; When the second indication indicates a second value, the first indication indicates a second port index group among a plurality of port index groups included in a second set; The first port index group and the second port index group have an association relationship. Device.

22. The association relationship is a one-to-one correspondence exists between port indexes in the first port index group and port indexes in the second port index group.

22. The apparatus of claim 21 .

23. 23. The apparatus of claim 21 or 22, wherein there is an offset between port indexes in the first port index group and port indexes in the second port index group.

24. the first set corresponds to a plurality of port indexes, each of the plurality of port index groups included in the first set has at least one of the plurality of port indexes; the offset is equal to the number of port indexes corresponding to the first set; 24. The apparatus of claim 23.

25. 25. Apparatus according to claim 23 or 24, wherein the value of the offset is 4, 8, 6 or 12.

26. The association relationship is the first port index group is a subset of the second port index group; 22. The apparatus of claim 21 .

27. The apparatus according to any one of claims 21 to 26, wherein the second indication information is carried in a radio resource control (RRC) message or a downlink control information (DCI).

28. the first indication indicates a first index value; the first index value is associated with the first port index group and the second port index group; 28. Apparatus according to any one of claims 21 to 27.

29. The first port index group and the second port index group correspond to the same time-frequency resource; the first port index group corresponds to a first cover code sequence, the second port index group corresponds to a second cover code sequence, and the first cover code sequence is orthogonal to the second cover code sequence.

29. Apparatus according to any one of claims 21 to 28.

30. The communication unit further comprises: sending a third indication to the terminal device; It is configured as follows: When the first indication information indicates the first port index group, the third indication information indicates whether the second port index group is assigned to another terminal device on the time-frequency resource assigned to the terminal device; or If the first indication information indicates the second port index group, the third indication information indicates whether the first port index group is assigned to the other terminal device on the time-frequency resource assigned to the terminal device.

30. Apparatus according to any one of claims 21 to 29.

31. 1. A communication device, comprising: a communication unit configured to receive first indication information from an access network device; having The communication unit is further configured to receive a second indication from the access network device; When the second indication indicates a first value, the first indication indicates a first port index group among a plurality of port index groups included in a first set; When the second indication indicates a second value, the first indication indicates a second port index group among a plurality of port index groups included in a second set; The first port index group and the second port index group have an association relationship. Device.

32. The association relationship is a one-to-one correspondence exists between port indexes in the first port index group and port indexes in the second port index group. The apparatus of claim 31 .

33. 33. The apparatus of claim 31 or 32, wherein there is an offset between port indexes in the first port index group and port indexes in the second port index group.

34. the first set corresponds to a plurality of port indexes, each of the plurality of port index groups included in the first set has at least one of the plurality of port indexes; the offset is equal to the number of port indexes corresponding to the first set; 34. The apparatus of claim 33.

35. 35. Apparatus according to claim 33 or 34, wherein the value of the offset is 4, 8, 6 or 12.

36. The association relationship is the first port index group is a subset of the second port index group; The apparatus of claim 31 .

37. The apparatus of claim 31 , wherein the second indication information is carried in an RRC message or a DCI.

38. the first indication indicates a first index value; the first index value is associated with the first port index group and the second port index group; 38. Apparatus according to any one of claims 31 to 37.

39. The first port index group and the second port index group correspond to the same time-frequency resource; the first port index group corresponds to a first cover code sequence, the second port index group corresponds to a second cover code sequence, and the first cover code sequence is orthogonal to the second cover code sequence.

39. Apparatus according to any one of claims 31 to 38.

40. The communication unit further comprises: receiving a third indication from the access network device; It is configured as follows: When the first indication information indicates the first port index group, the third indication information indicates whether the second port index group is assigned to another terminal device on the time-frequency resource assigned to the terminal device; or If the first indication information indicates the second port index group, the third indication information indicates whether the first port index group is assigned to the other terminal device on the time-frequency resource assigned to the terminal device.

40. Apparatus according to any one of claims 31 to 39.

41. 1. A communication method comprising: Sending first indication information to a terminal device, the first indication information indicating a DMRS configuration type; Sending second indication information to the terminal device, the second indication information indicating an index value, the index value being an index value in a port index group included in a first set, or the index value being an index value in a port index group included in a second set; The method according to claim 1,

42. 42. The method of claim 41, wherein the first set includes a first port index group and the second set includes a second port index group, the first port index group and the second port index group having an association relationship.

43. 43. The method of claim 42, wherein there is an offset between port indexes in the first port index group and port indexes in the second port index group.

44. 44. The method of claim 43, wherein the offset value is 4, 8, 6, or 12.

45. 1. A communication method comprising: receiving first indication information from an access network device, the first indication information indicating a DMRS configuration type; receiving a second indication from the access network device, the second indication indicating an index value, the index value being an index value in a port index group included in a first set, or the index value being an index value in a port index group included in a second set; The method according to claim 1,

46. 46. ​​The method of claim 45, wherein the first set includes a first port index group, the second set includes a second port index group, and the first port index group and the second port index group have an association relationship.

47. 47. The method of claim 46, wherein there is an offset between port indexes in the first port index group and port indexes in the second port index group.

48. 48. The method of claim 47, wherein the offset value is 4, 8, 6, or 12.

49. 1. A communication device, comprising: A communication unit configured to send first indication information to a terminal device, the first indication information indicating a DMRS configuration type. having The communication unit is further configured to send second indication information to the terminal device, the second indication information indicating an index value, the index value being an index value in a port index group included in a first set, or the index value being an index value in a port index group included in a second set. Device.

50. 50. The apparatus of claim 49, wherein the first set includes a first port index group and the second set includes a second port index group, the first port index group and the second port index group having an association relationship.

51. 51. The apparatus of claim 50, wherein there is an offset between port indexes in the first port index group and port indexes in the second port index group.

52. 52. The apparatus of claim 51, wherein the offset has a value of 4, 8, 6, or 12.

53. 1. A communication device, comprising: A communication unit configured to receive first indication information from an access network device, the first indication information indicating a DMRS configuration type; a communication unit configured to receive second indication information from the access network device, the second indication information indicating an index value, the index value being an index value in a port index group included in a first set, or the index value being an index value in a port index group included in a second set; An apparatus having

54. 54. The apparatus of claim 53, wherein the first set includes a first port index group and the second set includes a second port index group, the first port index group and the second port index group having an association relationship.

55. 55. The apparatus of claim 54, wherein there is an offset between port indexes in the first port index group and port indexes in the second port index group.

56. 56. The apparatus of claim 55, wherein the offset value is 4, 8, 6, or 12.

57. A communications device having a processor and a storage medium, the storage medium storing instructions which, when executed by the processor, perform a method according to any one of claims 1 to 10, or a method according to any one of claims 11 to 20, or a method according to any one of claims 41 to 44, or a method according to any one of claims 45 to 48.

58. A computer readable storage medium having instructions which, when executed by a processor, cause a method according to any one of claims 1 to 10 to be performed, or a method according to any one of claims 11 to 20 to be performed, or a method according to any one of claims 41 to 44 to be performed, or a method according to any one of claims 45 to 48 to be performed.

59. A computer program product comprising instructions which, when executed by a processor, cause a method according to any one of claims 1 to 10 to be performed, or a method according to any one of claims 11 to 20 to be performed, or a method according to any one of claims 41 to 44 to be performed, or a method according to any one of claims 45 to 48 to be performed.

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