Communication method and apparatus

Abstract

Provided in the present application are a communication method and apparatus, which can reduce the resource overheads of a demodulation reference signal (DMRS) and improve the data transmission performance. The method comprises: a terminal device receiving first information, and transmitting a DMRS on the basis of the first information, wherein the first information is used for indicating at least one of the following: N code-division-multiplexing (CDM) groups corresponding to the DMRS, the number M of CDM groups, which do not carry data, among the N CDM groups, and an index of at least one antenna port, which is used for transmitting the DMRS, among antenna ports corresponding to the N CDM groups; and the N CDM groups comprise at least one first CDM group, any first CDM group corresponds to m resource elements (REs), and any two REs among the m REs are separated by at least N-1 subcarriers in a frequency domain, N being an integer greater than 2, M being a positive integer less than or equal to N, and m being an integer greater than or equal to 2.

Description

Communication method and apparatus

[0001] Cross-reference to Related Applications

[0002] This application claims priority to the Chinese Patent Application No. 202410868703.X, filed on June 28, 2024, and entitled "A communication method and apparatus", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the field of communication technology, and in particular to a communication method and apparatus. BACKGROUND

[0004] A demodulation reference signal (DMRS) can be mapped on a physical channel together with data, and the DMRS is used for channel estimation when the physical channel is demodulated. The physical channel can be a physical downlink shared channel (PDSCH) or a physical uplink shared channel (PUSCH), for example.

[0005] The network side divides the antenna ports corresponding to the DMRS in the frequency domain by code division multiplexing (CDM) groups, and transmits the DMRS by occupying resource elements (REs) in units of CDM groups. Currently, two CDM groups are defined for the transmission of the DMRS, and each CDM group occupies 6 REs in each resource block (RB). The interval between two adjacent REs in the 6 REs is only one subcarrier, which results in a large resource overhead for transmitting the DMRS using at least one CDM group, and affects the data transmission performance. SUMMARY

[0006] The present application provides a communication method and apparatus, which reduces the number of resources mapped by the CDM group corresponding to the DMRS, to reduce the resource overhead occupied by the transmission of the DMRS, and thereby improve the performance of data transmission.

[0007] In a first aspect, an embodiment of the present application provides a communication method applied to a terminal device, comprising: receiving first information, the first information being used for indicating at least one of the following: N code division multiplexing (CDM) groups corresponding to a demodulation reference signal (DMRS), a quantity M of CDM groups in the N CDM groups that do not carry data, and an index of at least one antenna port in antenna ports corresponding to the N CDM groups and used for transmitting the DMRS; wherein the N CDM groups include at least one first CDM group, any first CDM group corresponds to m groups of resource elements (REs), and any 2 groups of REs in the m groups of REs are different by at least N-1 subcarriers in a frequency domain; the N is an integer greater than 2, the M is a positive integer less than or equal to the N, and the m is an integer greater than or equal to 2; and transmitting the DMRS according to the first information, wherein transmitting the DMRS includes transmitting the DMRS or receiving the DMRS.

[0008] The above design can reduce the quantity of REs occupied by the CDM groups for transmitting the DMRS, thereby reducing resource overhead corresponding to the DMRS, enhancing sparseness of resource occupied by the DMRS, reducing a preemption rate of DMRS transmission resource on data transmission resource, and improving performance of data transmission.

[0009] In a possible design, each group of REs in the m groups of REs includes 1 RE; or each group of REs in the m groups of REs includes at least 2 REs, the at least 2 REs occupy different time symbols, and the at least 2 REs occupy the same subcarrier. Providing multiple definitions of the quantity of REs included in each group of REs can adapt to different DMRS configuration scenarios and improve flexibility of implementation of the scheme.

[0010] In a possible design, indexes of subcarriers occupied by the m groups of REs corresponding to the first CDM group are determined based on the value of the N, the value of the m, and the index of the at least one antenna port used for transmitting the DMRS.

[0011] In a possible design, the method further includes: determining a power scaling factor corresponding to the DMRS according to the value of the M, the power scaling factor corresponding to the DMRS being used for determining transmission power of the DMRS. With this design, the transmission power of the DMRS can be flexibly adjusted based on the value of the M, which is suitable for different channel environments and is beneficial to improving communication performance.

[0012] For example, the N is 6, and the M is 1, 2, 3, 4, 5, 6 in turn, the DMRS corresponding power scaling factor is 0dB, -3dB, -4.77dB, -6dB, -6.99dB and -7.78dB in turn.

[0013] For another example, the N is 12, and the M is 1 to 12 in turn, the DMRS corresponding power scaling factor is 0dB, -3dB, -4.77dB, -6.02dB, -6.99dB, -7.78dB, -8.45dB, -9.03dB, -9.54dB, -10dB, -10.4dB and -10.79dB in turn.

[0014] For another example, the N is 24, and the M is 1 to 24 in turn, the DMRS corresponding power scaling factor is 0dB, -3dB, -4.77dB, -6.02dB, -6.99dB, -7.78dB, -8.45dB, -9.03dB, -9.54dB, -10dB, -10.4dB, -10.79dB, -11.14dB, -11.46dB, -11.76dB, -12.04dB, -12.30dB, -12.55dB, -12.79dB, -13.01dB, -13.22dB, -13.42dB, -13.62dB and -13.8dB in turn.

[0015] In a possible design, the receiving the first information includes: receiving first indication information, where the first indication information is used to indicate the number M of CDM groups that do not carry data among the N CDM groups, and an index of at least one antenna port used to transmit the DMRS among the antenna ports corresponding to the N CDM groups. Through such simple indication, the indication overhead related to the first information can be reduced.

[0016] In a possible design, the receiving the first information includes: receiving second indication information and third indication information, where the second indication information is used to indicate at least one second CDM group among the N CDM groups, and the third indication information is used to indicate indexes of at least one antenna port corresponding to the at least one second CDM group respectively; and receiving fourth indication information, where the fourth indication information is used to indicate the number M of CDM groups that do not carry data among the N CDM groups. Such design can enable the terminal device to quickly determine the correspondence between the antenna ports and the CDM groups based on the first information, and help improve the efficiency of DMRS resolution and channel estimation.

[0017] In a possible design, the receiving the first information further includes: receiving fifth indication information, where the fifth indication information is used to indicate the N CDM groups corresponding to the DMRS.

[0018] In a possible design, before the receiving the first information, the method further includes: sending second information, where the second information is used to indicate that the terminal device supports that the number of the CDM groups corresponding to the DMRS is the N. In this design, the terminal device reports the number of the CDM groups corresponding to the DMRS, which improves flexibility of implementation of the scheme and ensures normal implementation of the scheme.

[0019] In a second aspect, an embodiment of the present application provides a communication method, applied to a network device, including: sending first information, where the first information is used to indicate at least one of the following: N code division multiplexing (CDM) groups corresponding to a demodulation reference signal (DMRS), a number M of CDM groups in the N CDM groups that do not carry data, and an index of at least one antenna port in antenna ports corresponding to the N CDM groups and used to transmit the DMRS; where the N CDM groups include at least one first CDM group, any first CDM group corresponds to m groups of resource elements (REs), any 2 groups of REs in the m groups of REs are different by at least N-1 subcarriers in a frequency domain; the N is an integer greater than 2, the M is a positive integer less than or equal to the N, and the m is an integer greater than or equal to 2; and transmitting the DMRS according to the first information. Where transmitting the DMRS includes receiving the DMRS or sending the DMRS.

[0020] In a possible design, each group of REs in the m groups of REs includes 1 RE; or each group of REs in the m groups of REs includes at least 2 REs, the at least 2 REs occupy different time symbols, and the at least 2 REs occupy the same subcarrier.

[0021] In a possible design, indexes of subcarriers occupied by the m groups of REs corresponding to the first CDM group are determined based on a value of the N, a value of the m, and the index of the at least one antenna port used to transmit the DMRS.

[0022] In a possible design, the number M of the CDM groups in the N CDM groups that do not carry data is used to determine a power scaling factor corresponding to the DMRS, and the power scaling factor corresponding to the DMRS is used to determine a transmission power DMRS of the DMRS.

[0023] For example, the N is 6, and the M is 1, 2, 3, 4, 5, 6 in turn, the DMRS corresponding power scaling factor is 0 dB, -3 dB, -4.77 dB, -6 dB, -6.99 dB and -7.78 dB in turn.

[0024] For another example, the N is 12, and the M is 1 to 12 in turn, the DMRS corresponding power scaling factor is 0 dB, -3 dB, -4.77 dB, -6.02 dB, -6.99 dB, -7.78 dB, -8.45 dB, -9.03 dB, -9.54 dB, -10 dB, -10.4 dB and -10.79 dB in turn.

[0025] For another example, the N is 24, and the M is 1 to 24 in turn, the DMRS corresponding power scaling factor is 0 dB, -3 dB, -4.77 dB, -6.02 dB, -6.99 dB, -7.78 dB, -8.45 dB, -9.03 dB, -9.54 dB, -10 dB, -10.4 dB, -10.79 dB, -11.14 dB, -11.46 dB, -11.76 dB, -12.04 dB, -12.30 dB, -12.55 dB, -12.79 dB, -13.01 dB, -13.22 dB, -13.42 dB, -13.62 dB and -13.8 dB in turn.

[0026] In a possible design, the sending the first information includes: sending first indication information, the first indication information being used to indicate the number M of the CDM groups in the N CDM groups that do not carry data, and an index of at least one antenna port in the antenna ports corresponding to the N CDM groups that is used to transmit the DMRS.

[0027] In a possible design, the sending the first information includes: sending second indication information and third indication information, the second indication information being used to indicate at least one second CDM group in the N CDM groups, and the third indication information being used to indicate an index corresponding to at least one antenna port in the antenna ports corresponding to the at least one second CDM group that is used to transmit the DMRS respectively; and sending fourth indication information, the fourth indication information being used to indicate the number M of the CDM groups in the N CDM groups that do not carry data.

[0028] In a possible design, the sending the first information further includes: sending fifth indication information, the fifth indication information being used to indicate the N code division multiplexing (CDM) groups corresponding to the DMRS.

[0029] In a possible design, before the first information is sent, the method further includes: receiving second information, where the second information is used to indicate that the terminal device supports that the number of CDM groups corresponding to the DMRS is the N.

[0030] In a third aspect, embodiments of the present disclosure provide a communication apparatus, which can be a terminal device, a device, a module or a chip in a terminal device, or an apparatus that can be used in combination with a terminal device. In one design, the communication apparatus can include a module corresponding to each of the methods / operations / steps / actions described in the first aspect, which can be hardware circuitry, software, or a combination of hardware circuitry and software. In one design, the communication apparatus can include a processing module and a communication module, where the communication module includes a sending unit and a receiving unit. Optionally, the processing module can be replaced by a processing unit.

[0031] The communication module is configured to receive first information, where the first information is used to indicate at least one of the following: N CDM groups corresponding to a DMRS, a number M of CDM groups in the N CDM groups that do not carry data, and an index of at least one antenna port in antenna ports corresponding to the N CDM groups and used to transmit the DMRS; where the N CDM groups include at least one first CDM group, any first CDM group corresponds to m groups of REs, and any 2 groups of REs in the m groups of REs are different by at least N-1 subcarriers in the frequency domain; where the N is an integer greater than 2, the M is a positive integer less than or equal to the N, and the m is an integer greater than or equal to 2.

[0032] The processing module is configured to transmit, by the communication module, the DMRS according to the first information, where transmitting the DMRS includes sending the DMRS or receiving the DMRS.

[0033] In a possible design, each group of REs in the m groups of REs includes 1 RE; or each group of REs in the m groups of REs includes at least 2 REs, the at least 2 REs occupy different time symbols, and the at least 2 REs occupy the same subcarrier.

[0034] In a possible design, the index of the subcarriers occupied by the m groups of REs corresponding to the first CDM group is determined based on the value of the N, the value of the m, and the index of the at least one antenna port used to transmit the DMRS.

[0035] In a possible design, the processing module is further configured to determine, according to the value of the M, a power scaling factor corresponding to the DMRS, where the power scaling factor corresponding to the DMRS is used to determine the transmission power of the DMRS.

[0036] For example, the N is 6, and the M is 1, 2, 3, 4, 5, 6 in turn, the DMRS corresponding power scaling factor is 0dB, -3dB, -4.77dB, -6dB, -6.99dB and -7.78dB in turn.

[0037] For another example, the N is 12, and the M is 1 to 12 in turn, the DMRS corresponding power scaling factor is 0dB, -3dB, -4.77dB, -6.02dB, -6.99dB, -7.78dB, -8.45dB, -9.03dB, -9.54dB, -10dB, -10.4dB and -10.79dB in turn.

[0038] For another example, the N is 24, and the M is 1 to 24 in turn, the DMRS corresponding power scaling factor is 0dB, -3dB, -4.77dB, -6.02dB, -6.99dB, -7.78dB, -8.45dB, -9.03dB, -9.54dB, -10dB, -10.4dB, -10.79dB, -11.14dB, -11.46dB, -11.76dB, -12.04dB, -12.30dB, -12.55dB, -12.79dB, -13.01dB, -13.22dB, -13.42dB, -13.62dB and -13.8dB in turn.

[0039] In a possible design, the communication module is specifically configured to receive first indication information, where the first indication information is used to indicate a quantity M of CDM groups in the N CDM groups that do not carry data, and an index of at least one antenna port in the N CDM group corresponding antenna ports used to transmit the DMRS.

[0040] In a possible design, the communication module is specifically configured to receive second indication information and third indication information, where the second indication information is used to indicate at least one second CDM group in the N CDM groups, and the third indication information is used to indicate an index corresponding to at least one antenna port in the at least one second CDM group corresponding antenna ports used to transmit the DMRS; and receive fourth indication information, where the fourth indication information is used to indicate a quantity M of CDM groups in the N CDM groups that do not carry data.

[0041] In a possible design, the communication module is specifically configured to receive fifth indication information, where the fifth indication information is used to indicate N code division multiplexing (CDM) groups corresponding to the DMRS.

[0042] In a possible design, the communication module is further configured to, before receiving the first information, send second information, where the second information is used to indicate that the terminal device supports the number of CDM groups corresponding to the DMRS to be the N.

[0043] In a fourth aspect, embodiments of the present disclosure provide a communication apparatus, which can be a terminal device, a device, a module or a chip in a terminal device, or an apparatus capable of being used with a terminal device. In one design, the communication apparatus can include a module corresponding to each of the methods / operations / steps / actions described in the first aspect, which can be hardware circuitry, software, or a combination of hardware circuitry and software. In one design, the communication apparatus can include a processing module and a communication module, where the communication module includes a sending unit and a receiving unit. Optionally, the processing module can also be replaced by a processing unit.

[0044] The communication module is configured to send first information, where the first information is used to indicate at least one of the following: N code division multiplexing (CDM) groups corresponding to a demodulation reference signal (DMRS), a number M of CDM groups in the N CDM groups that do not carry data, and an index of at least one antenna port in antenna ports corresponding to the N CDM groups and used to transmit the DMRS; where the N CDM groups include at least one first CDM group, any first CDM group corresponds to m groups of resource elements (REs), and any 2 groups of REs in the m groups of REs differ by at least N-1 subcarriers in a frequency domain; the N is an integer greater than 2, the M is a positive integer less than or equal to the N, and the m is an integer greater than or equal to 2.

[0045] The processing module is configured to transmit the DMRS according to the first information, where transmitting the DMRS includes receiving the DMRS or sending the DMRS.

[0046] In a possible design, each group of REs in the m groups of REs includes 1 RE; or each group of REs in the m groups of REs includes at least 2 REs, the at least 2 REs occupy different time symbols, and the at least 2 REs occupy the same subcarrier.

[0047] In a possible design, indexes of subcarriers occupied by the m groups of REs corresponding to the first CDM group are determined based on a value of the N, a value of the m, and the index of the at least one antenna port used to transmit the DMRS.

[0048] In a possible design, the number M of CDM groups in the N CDM groups that do not carry data is used to determine a power scaling factor corresponding to the DMRS, and the power scaling factor corresponding to the DMRS is used to determine a transmission power DMRS of the DMRS.

[0049] For example, the N is 6, and the M is 1, 2, 3, 4, 5, 6 in turn, the DMRS corresponding power scaling factor is 0dB, -3dB, -4.77dB, -6dB, -6.99dB and -7.78dB in turn.

[0050] For another example, the N is 12, and the M is 1 to 12 in turn, the DMRS corresponding power scaling factor is 0dB, -3dB, -4.77dB, -6.02dB, -6.99dB, -7.78dB, -8.45dB, -9.03dB, -9.54dB, -10dB, -10.4dB and -10.79dB in turn.

[0051] For another example, the N is 24, and the M is 1 to 24 in turn, the DMRS corresponding power scaling factor is 0dB, -3dB, -4.77dB, -6.02dB, -6.99dB, -7.78dB, -8.45dB, -9.03dB, -9.54dB, -10dB, -10.4dB, -10.79dB, -11.14dB, -11.46dB, -11.76dB, -12.04dB, -12.30dB, -12.55dB, -12.79dB, -13.01dB, -13.22dB, -13.42dB, -13.62dB and -13.8dB in turn.

[0052] In a possible design, the communication module is specifically configured to send first indication information, where the first indication information is used to indicate the number M of CDM groups in the N CDM groups that do not carry data, and an index of at least one antenna port in the N CDM group corresponding antenna ports used for transmitting the DMRS.

[0053] In a possible design, the communication module is specifically configured to send second indication information and third indication information, where the second indication information is used to indicate at least one second CDM group in the N CDM groups, the third indication information is used to indicate indexes corresponding to at least one antenna port in the at least one second CDM group corresponding antenna ports used for transmitting the DMRS respectively; and send fourth indication information, where the fourth indication information is used to indicate the number M of CDM groups in the N CDM groups that do not carry data.

[0054] In a possible design, the communication module is specifically configured to send fifth indication information, where the fifth indication information is used to indicate the N code division multiplexing (CDM) groups corresponding to the DMRS. In a possible design, the communication module is specifically configured to send fifth indication information, where the fifth indication information is used to indicate the N code division multiplexing (CDM) groups corresponding to the DMRS.

[0055] In a possible design, the communication module is further configured to receive second information before the first information is sent, where the second information is used to indicate that the terminal device supports the number of CDM groups corresponding to the DMRS to be the N.

[0056] In a fifth aspect, an embodiment of the present application provides a communication apparatus, which comprises a processor configured to implement the method described in any one of the first aspect to the second aspect. The processor is coupled to a memory, and the memory is configured to store instructions and data. When the processor executes the instructions stored in the memory, the method described in the first aspect can be implemented. Optionally, the communication apparatus can further comprise the memory. The communication apparatus can further comprise a communication interface, which is configured to enable the communication apparatus to communicate with other devices. For example, the communication interface can be a transceiver, a circuit, a bus, a module, a pin, or another type of communication interface.

[0057] In a sixth aspect, an embodiment of the present application provides a communication apparatus, which comprises a logic circuit and an interface circuit. The interface circuit is configured to communicate with a module outside the communication apparatus. The logic circuit is configured to execute a computer program, so that the communication apparatus performs the method provided in any one of the first aspect to the second aspect.

[0058] In a seventh aspect, an embodiment of the present application further provides a computer program, which, when executed on a computer, enables the computer to perform the method provided in any one of the first aspect to the second aspect.

[0059] In an eighth aspect, an embodiment of the present application further provides a computer program product, which comprises instructions. When the instructions are executed on a computer, the computer performs the method provided in any one of the first aspect to the second aspect.

[0060] In a ninth aspect, an embodiment of the present application further provides a computer readable storage medium, which stores a computer program or instructions. When the computer program or instructions are executed on a computer, the computer performs the method provided in any one of the first aspect to the second aspect.

[0061] In a tenth aspect, an embodiment of the present application further provides a chip, which is configured to read a computer program stored in a memory, and perform the method provided in any one of the first aspect to the second aspect.

[0062] In an eleventh aspect, the embodiments of the present application further provide a chip system, which comprises a processor configured to support a computer device to implement the method provided in any one of the first aspect to the second aspect. In a possible design, the chip system further comprises a memory configured to store programs and data necessary for the computer device. The chip system can be composed of a chip, or can include the chip and other discrete devices.

[0063] The effects of the solutions provided in any one of the second aspect to the eleventh aspect can be referred to the corresponding description in the first aspect. BRIEF DESCRIPTION OF DRAWINGS

[0064] FIG. 1 is a schematic diagram of an architecture of a communication system provided by the embodiments of the present application;

[0065] FIG. 2A is a schematic diagram of one of the patterns of DMRS resource mapping defined in the prior art;

[0066] FIG. 2B is a schematic diagram of one of the patterns of DMRS resource mapping defined in the prior art;

[0067] FIG. 3 is a schematic diagram of one of the flowcharts of a communication method provided by the embodiments of the present application;

[0068] FIG. 4A is a schematic diagram of one of the patterns of DMRS resource mapping provided by the embodiments of the present application;

[0069] FIG. 4B is a schematic diagram of one of the patterns of DMRS resource mapping provided by the embodiments of the present application;

[0070] FIG. 5A is a schematic diagram of one of the patterns of DMRS resource mapping provided by the embodiments of the present application;

[0071] FIG. 5B is a schematic diagram of one of the patterns of DMRS resource mapping provided by the embodiments of the present application;

[0072] FIG. 6A is a schematic diagram of one of the patterns of DMRS resource mapping provided by the embodiments of the present application;

[0073] FIG. 6B is a schematic diagram of one of the patterns of DMRS resource mapping provided by the embodiments of the present application;

[0074] FIG. 7 is a schematic diagram of one of the flowcharts of a communication method provided by the embodiments of the present application;

[0075] FIG. 8 is a schematic diagram of one of the structures of a communication device provided by the embodiments of the present application;

[0076] FIG. 9 is a schematic diagram of one of the structures of a communication device provided by the embodiments of the present application;

[0077] FIG. 10 is a schematic diagram of a chip provided by the embodiments of the present application. DETAILED DESCRIPTION

[0078] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings.

[0079] In the embodiments of the present application, the number of nouns, unless otherwise specified, represents "a singular noun or a plural noun", i.e. "one or more". "At least one" means one or more, and "a plurality of" means two or more. "And / or" describes the association relationship of the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can represent the following three cases: A exists alone, A and B exist together, and B exists alone, wherein A and B can be singular or plural. The character " / " generally represents that the associated objects before and after it are in an "or" relationship. For example, A / B represents A or B. "At least one of the following" or similar expressions means any combination of these items, including any combination of single item or multiple items. For example, at least one of a, b, or c represents a, b, c, a and b, a and c, b and c, or a and b and c, wherein a, b, and c can be single or multiple.

[0080] In addition, the terms "comprising" and "having" mentioned in the embodiments of the present application are not exclusive. For example, a process, method, system, product or device comprising a series of steps or modules is not limited to the listed steps or modules, and can also include steps or modules that are not listed.

[0081] The scheme provided in the embodiments of the present application can be applied to any communication system (or network) including a terminal device and a network device, for example, can be applied to, but is not limited to, a fourth generation (4G) system (also referred to as a long term evolution (LTE) system), a fifth generation (5G) system (also referred to as a new radio (NR) system), or can also be applied to a next generation mobile communication system or a future communication system, and the like, and the specific system is not limited. The device involved in the embodiments of the present application can be a certain device, a software module in the device, or a hardware module (such as a chip) in the device, and the like. For example, the device for realizing the function of the terminal device can be a terminal device, or can be a device capable of supporting the terminal device to realize the function, such as a chip system, which can be installed in the terminal device. In the technical scheme provided in the embodiments of the present application, the device for realizing the function of the terminal device is taken as an example to be described as a terminal device. In addition, the device for realizing the function of the network device can be a network device, or can be a device capable of supporting the network device to realize the function, such as a chip system, which can be installed in the network device. In the technical scheme provided in the embodiments of the present application, the device for realizing the function of the network device is taken as an example to be described as a network device.

[0082] Referring to FIG. 1, it is a structural schematic diagram of a communication system to which the embodiments of the present application are applicable. The communication system includes at least one network device and at least one terminal device, and the like. Any network device in the at least one network device can communicate with the at least one terminal device. Optionally, any two terminal devices in the at least one terminal device can also communicate with each other. In FIG. 1, it is taken as an example that the at least one terminal device includes a first terminal device, a second terminal device, a third terminal device and a fourth terminal device, and it is taken as an example that the at least one network device includes a first network device.

[0083] A terminal device is a device with wireless transceiver function. The terminal device can be a fixed device, a mobile device, a handheld device, a wearable device, a vehicle-mounted device, or a wireless device (e.g., a communication module or a chip system, etc.) built-in the above devices. The terminal device is used to connect people, things, machines, etc., and can be widely used in various scenarios, such as cellular communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) communication, machine-to-machine / machine-type communications (M2M / MTC), urban air mobility (UAM), internet of things (IoT), virtual reality (VR), augmented reality (AR), industrial control, self driving, remote medical, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, unmanned aerial vehicle, robot, etc. The terminal device can be referred to as user equipment (UE), terminal, access station, UE station, remote station, wireless communication device, or user device, mobile station (MS), subscriber unit, cellular phone, smart phone, car, tablet computer, smart speaker, train detector, or fueling station sensor, etc. The terminal device can be used to collect data, receive control information and downlink data of a network device, and transmit one or more of electromagnetic waves or uplink data to the network device.

[0084] The network device can include an access network element (or, referred to as an access network node). The access network element is a device with wireless transceiving function, used for communicating with the terminal device. The access network element includes but is not limited to the base station (BTS, Node B, eNodeB / eNB, or gNodeB / gNB), transmission reception point (TRP), base station of subsequent evolution of 3GPP, access node in a wireless fidelity (WiFi) system, wireless relay node, wireless backhaul node, satellite, unmanned aerial vehicle, and the like in the communication system. The base station can be a macro base station, micro base station, pico base station, microcell, relay station, and the like. Multiple base stations can support the network of the same access technology mentioned above, or support the network of different access technologies mentioned above. The base station can include one or more co-sited or non-co-sited transmission reception points. The access network element can also be a wireless controller in a cloud radio access network (C(R)AN) scenario, a centralized unit (CU), also referred to as a convergence unit, and / or a distributed unit (DU). The access network element can also be a server, a wearable device, a vehicle-mounted device, and the like. For example, the access network element in vehicle to everything (V2X) technology can be a road side unit (RSU). The following describes the access network element by taking the base station as an example. Multiple access network elements in the communication system can be the same type of base station, or different types of base station. The base station can communicate with the terminal device, or communicate with the terminal device through a relay station. The terminal device can communicate with multiple base stations in different access technologies.

[0085] In a possible architecture of an access network device, the access network device includes a central unit (CU) and / or a distributed unit (DU). The CU and the DU can be understood as a division of the access network device from a logical function perspective. The CU and the DU can be physically separated or deployed together, and embodiments of the present application do not make a specific limitation in this regard. One CU can be connected with one DU, or multiple DUs can share one CU. The CU and the DU can be divided according to a protocol stack, and in one possible manner, radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) layers are deployed in the CU, and the remaining radio link control (RLC) layer, media access control (MAC) layer, and physical layer are deployed in the DU. The CU and the DU are not completely limited to the above-mentioned protocol stack manner in embodiments of the present application, and other division manners can also be used, for example, division according to service types.

[0086] The access network device in embodiments of the present application can also refer to a centralized unit control plane (CU-CP) node or a centralized unit user plane (CU-UP) node, or include the CU-CP and the CU-UP. The CU-CP is responsible for control plane functions, and mainly includes RRC and PDCP-C. The PDCP-C is mainly responsible for encryption and decryption of control plane data, integrity protection, data transmission, and the like. The CU-UP is responsible for user plane functions, and mainly includes SDAP and PDCP-U. The SDAP is mainly responsible for processing data of a core network and mapping a flow to a bearer. The PDCP-U is mainly responsible for encryption and decryption of a data plane, integrity protection, header compression, sequence number maintenance, data transmission, and the like.

[0087] In different systems, the CU (including the CU-CP or the CU-UP) or the DU can also have different names, but a person skilled in the art can understand the meanings thereof. For example, in an open radio access network (O-RAN) system, the CU can also be referred to as an O-CU (open CU), the DU can also be referred to as an O-DU, the CU-CP can also be referred to as an O-CU-CP, and the CU-UP can also be referred to as an O-CU-UP.

[0088] In addition, the communication system can further include a core network element and / or an OAM. The core network element is configured to implement at least one of the following functions: mobile management, data processing, session management, policy and charging, etc. The names of devices implementing the core network function in systems of different access technologies can be different, and the embodiments of the present application do not limit this. Taking the 5G system as an example, the core network element includes: an access and mobility management function (AMF), a session management function (SMF), or a user plane function (UPF), etc. The OAM can also be referred to as an operation administration and maintenance (OAM) element, referred to as OAM for short. The operation mainly completes the analysis, prediction, planning and configuration of the daily network and service; the maintenance mainly completes the daily operation activities of the test and fault management of the network and service, and the OAM can detect the network running state, optimize the network connection and performance, improve the network running stability, and reduce the network maintenance cost.

[0089] The currently defined DMRS related parameters mentioned in the background art will be introduced below taking the communication system shown in FIG. 1 as an example.

[0090] The network device indicates the antenna port corresponding to the DMRS currently scheduled by the terminal device through the value of the antenna port field in the downlink control information (DCI). The antenna port corresponding to the DMRS refers to the antenna port used to transmit the DMRS. In the embodiments of the present application, the antenna port can be replaced by the description of the DMRS port (DMRS port), and it can also be understood that: one antenna port corresponds to one DMRS port, for example, the sum of the index of the antenna port 1000 and the index of the corresponding DMRS port.

[0091] Different antenna ports (or DMRS ports) are divided in the frequency domain to obtain multiple CDM groups, denoted as CDM group(s). The antenna ports in the same CDM group are expanded in the time domain and / or the frequency domain by using an orthogonal cover code (OCC), so as to ensure the orthogonality of different ports. In the following, the CDM group(s) is simply described as a CDM group. The symbol mentioned in the embodiments of the present application is, for example, an orthogonal frequency division multiplexing (OFDM) symbol.

[0092] The terminal device can determine the antenna port corresponding to the terminal device and the number of CDM groups without data (number of DMRS CDM group(s) without data) according to the value of the antenna port field and the pre-stored first table. The first table includes multiple antenna ports, the number of CDM groups corresponding to each antenna port in the multiple antenna ports, and the number of CDM groups without data transmission. It can be understood that the CDM group without data refers to the CDM group used only for transmitting DMRS.

[0093] According to different DMRS port (Port) division, the protocol defines two DMRS types, configuration type 1 (Type 1) and configuration type 2 (Type 2). The following takes the DMRS configuration type (configuration type) of DMRS Type 1 as an example to introduce the first table.

[0094] Table 1 is an example of the first table, which shows the antenna port mapping table of DMRS Type 1 in single symbol configuration. The single symbol configuration refers to the number of front-load symbols (Number of front-load symbols) being 1 symbol. At present, DMRS Type 1 is defined to support a maximum of 4 antenna ports (DMRS ports) in single symbol configuration, and the 4 antenna ports are divided into 2 CDM groups, each CDM group corresponding to 2 antenna ports.

[0095] Table 1

[0096] As shown in Table 1 above, the indexes of 4 DMRS ports are denoted as 0~3, in the case that the value of the antenna port field is equal to 0, then the DMRS port(s) index is 0, so the antenna port index is determined as 1000+0 (i.e. 1000), and the number of CDM groups without data is 1. In the case that the value of the antenna port field is equal to 1, then the DMRS port(s) index is 1, so the antenna port index is determined as 1000+1 (i.e. 1001), and the number of CDM groups without data is 1, and so on.

[0097] Table 2 shows another example of the first table, which shows the antenna port mapping table of DMRS Type 1 in the case of double symbol configuration. The double symbol configuration means that the number of front-load symbols is up to 2. Currently, DMRS Type 1 supports up to 8 antenna ports (DMRS ports) in the case of double symbol configuration, and the 8 antenna ports are divided into 2 CDM groups, and each CDM group corresponds to 4 antenna ports.

[0098] Table 2

[0099] As shown in Table 2 above, the indexes of 8 DMRS ports are denoted as 0~7, in the case that one code word is used, and the value of the antenna port field is equal to 0, then the number of front-load symbols is actually 1, and the DMRS port(s) index is 0, so the antenna port index is determined as 1000+0 (i.e. 1000), and the number of CDM groups without data is 1. In the case that two code words are used, and the value of the antenna port field is equal to 0, then the number of front-load symbols is actually 2, and the DMRS port(s) index includes 0-4, so the antenna port index is determined as 1000+0 (i.e. 1000), 1000+1 (i.e. 1001), 1000+2 (i.e. 1002), 1000+3 (i.e. 1003), 1000+4 (i.e. 1004), and the number of CDM groups without data is 2, and so on.

[0100] When the number of CDM groups without carrying data in Table 1 or Table 2 is 1, it means that one of the two CDM groups for DMRS division without carrying data is only used for DMRS transmission; and the remaining one CDM group except the CDM group without carrying data can be used for data transmission and / or DMRS transmission.

[0101] In addition, it can be understood that the configuration type of the DMRS is configured by a high-layer parameter dmrs-Type. Whether the DMRS symbol is a single symbol or a double symbol is determined by a high-layer parameter maxLength and / or an Antenna port field in DCI, for example, when maxLength is 1, it means single symbol configuration, that is, the DMRS symbol is a single symbol; when maxLength is 2, it means double symbol configuration, if the number of pre-DMRS symbols indicated in the DCI is 1, the DMRS symbol is a single symbol; or, when maxLength is 2, it means double symbol configuration, if the number of pre-DMRS symbols indicated in the DCI is 2, the DMRS symbol is a double symbol.

[0102] Regarding the transmission power control of the DMRS, taking the DMRS mapped to the PDSCH as an example, the network device configures the power factor ratio (energy per resource element, EPRE) of the downlink data and the DMRS transmission. For the DMRS associated with the PDSCH, the ratio of the PDSCH EPRE (denoted as P PDSCH ) to the DMRS EPRE (denoted as P DMRS ) is In the embodiments of the present application, It can be understood as the power scaling factor of the PDSCH DMRS, which is referred to as the power scaling factor hereinafter. The network device or the terminal device can determine the power scaling factor corresponding to the DMRS based on the configuration type of the DMRS, the number of CDM groups without carrying data, and a second table. The second table includes a plurality of numbers of CDM groups without carrying data, and a power scaling factor corresponding to each number of CDM groups without carrying data. Please refer to Table 3, which is an example of the second table.

[0103] Table 3

[0104] As shown in Table 3 above, in the case that the number of CDM groups without carrying data is 1 and the configuration type of DMRS is DMRS configuration type 1, the power scaling factor is 0 dB. In the case that the number of CDM groups without carrying data is 2 and the configuration type of DMRS is DMRS configuration type 1, the power scaling factor is -3 dB. In the case that the number of CDM groups without carrying data is 3 and the configuration type of DMRS is DMRS configuration type 1, there is no power scaling factor, which is represented as "-" in Table 3. In the case that the number of CDM groups without carrying data is 3 and the configuration type of DMRS is DMRS configuration type 2, the power scaling factor is -4.77 dB. Optionally, the DMRS configuration Type 1 in the embodiments of the present application can also be referred to as DMRS Type 1, and the DMRS configuration Type 2 can also be referred to as DMRS Type 2.

[0105] In addition, it can be understood that, in terms of power, the dB value and the linear value (denoted as X) satisfy: X (dB) = 10 x lg (X); wherein, lg represents the logarithm with base 10. Based on this, the dB value in Table 3 is determined by the linear value of the corresponding CDM group without carrying data, for example, 0 dB corresponds to -10 x lg (1), 0 dB indicating that no power change is made to the DMRS. -3 dB corresponds to -10 x lg (2), indicating that the DMRS power is increased by 3 dB compared with the downlink data power, that is, the DMRS power is twice the downlink data power. -4.77 dB corresponds to -10 x lg (3), indicating that the DMRS power is increased by 4.77 dB compared with the downlink data power, that is, the DMRS power is twice the downlink data power. As can be seen, when the number of CDM groups without carrying data indicated by the DCI is not 1, the transmission power of the DMRS can be increased, so that the DMRS power has a gain of 3 dB or 4.77 dB, which is beneficial to improving the channel estimation performance.

[0106] Further, resource mapping of the DMRS pattern is performed based on the above configuration parameters. Taking PDSCH DMRS as an example, currently two configuration types of DMRS correspond to two DMRS patterns respectively. It is defined that, under the configuration of antenna port p j and subcarrier spacing μ, the resource mapping of the DMRS can be understood according to the following formula (1), that is, the product of the pseudo-random sequence r, the power scaling factor and the time-frequency domain OCC is mapped to the time-frequency resource of the DMRS.

[0107] wherein, denotes the aforementioned PDSCH DMRS power scaling factor. k has different values under different DMRS Type configurations, so as to realize different DMRS pattern mappings. r denotes a sequence, and some possible sequences are exemplified as follows: a pseudo-random sequence, for example, a Gold sequence, which is applicable to scenarios of mapping DMRS on PDSCH and PUSCH; or a low peak to average power ratio (PAPR) sequence, for example, a Zadoff-Chu sequence, which is only applicable to scenarios of mapping DMRS on PUSCH.

[0108] k denotes the index of a subcarrier in the frequency domain to which a DMRS-occupied RE is mapped. k' has values of 0 and 1, and n is an integer, in one possible implementation, the value of n is related to the number of resource blocks (RBs) to which PDSCH / DMRS is allocated and the length of an OCC sequence used in the frequency domain. One RB generally includes 12 REs, and one RE refers to a time-frequency resource occupying one symbol and one subcarrier. Different REs in one RB occupy the same symbol, but different subcarriers.

[0109] l denotes the index of a symbol in the time domain to which a DMRS-occupied RE is mapped, referred to as a DMRS symbol index. denotes the index of a starting symbol in the time domain to which a DMRS is mapped, referred to as a DMRS starting symbol index. l' denotes a DMRS symbol relative index, that is, the difference between a DMRS symbol index and a DMRS starting symbol index; and v denotes the number of antenna ports to which a DMRS is allocated.

[0110] w f and w t denote OCCs in the frequency domain and in the time domain, respectively. By defining OCC mapping tables under different DMRS Type configurations, w f and w t are determined according to the value of an antenna port corresponding to a DMRS, the OCC mapping table is queried to determine w f (k') and w t(l′). As illustrated in FIG. 2A, in case of single-symbol DMRS configuration, 4 DMRS ports (P0~P3) are divided into 2 CDM groups, and 2 DMRS ports in the same CDM group can be distinguished by OCC with length 2 in frequency domain. In one RB, each CDM group occupies the same 1 symbol and different 6 REs. As illustrated in FIG. 2B, in case of double-symbol DMRS configuration, 8 DMRS ports (P0~P7) are divided into 2 CDM groups, and 4 DMRS ports in the same CDM group can be distinguished by OCC with length 2 in frequency domain and OCC with length 2 in time domain. In one RB containing 12 REs, each CDM group occupies 2 symbols and 6 REs.

[0111] As an example, Table 4 below illustrates an OCC mapping table in case of DMRS Type 1 configuration. It can be understood that in this example, w f (k′) and w t k′ = 0, 1, l′ = 0, 1 in (l′).

[0112] Table 4

[0113] Currently, DMRS Type 1 can be configured in urban air mobility (UAM) scenarios. UAM scenarios utilize unmanned aerial vehicles for urban air mobility, providing services in application fields such as manned transportation and logistics transportation. The unmanned aerial vehicle in the UAM scenario can be understood as the aforementioned terminal device, and in the 5G communication system, the unmanned aerial vehicle communicates with the gNB (i.e., the aforementioned network device) through the ground 5G NR. With the development of business, UAM needs to ensure the high rate and reliability of communication transmission, and the rate requirement of uplink transmission in the UAM scenario reaches 25 Mbps, and the rate requirement of downlink transmission reaches 100 Mbps. Since there is usually a direct diameter in the UAM scenario, the delay spread of channel transmission is small, and the resource requirement of DMRS occupation is small. Using the aforementioned existing DMRS Type 1 configuration for resource mapping and channel estimation, there is a large resource overhead.

[0114] In view of this, the embodiment of the present application provides a communication method, by redefining the configuration parameters related to DMRS Type 1, such as defining the CDM groups of DMRS with a number greater than 2, to reduce the number of REs occupied by each CDM group in the same frequency domain resource, thereby reducing the resource overhead corresponding to DMRS. Correspondingly, the network side can also define other configuration parameters adapted to the CDM groups of DMRS with a number greater than 2, and configure them to the terminal device. The communication method provided by the embodiment of the present application will be described in detail below in conjunction with FIG. 3.

[0115] As shown in FIG. 3, the communication method comprises the following steps.

[0116] S301, the network device sends first information to the terminal device.

[0117] The first information is used to indicate at least one of the following: N CDM groups corresponding to DMRS, the number M of CDM groups in the N CDM groups that do not carry data, and the index of at least one antenna port in the antenna ports corresponding to the N CDM groups for transmitting the DMRS.

[0118] Wherein, the type of DMRS is DMRS Type 1. The N is an integer greater than 2, and the M is an integer less than or equal to N. Exemplarily, N is 6, and M is an integer from 1 to 6; or, N is 12, and M is an integer from 1 to 12; or, N is 24, and M is an integer from 1 to 24.

[0119] Optionally, in the case of single-symbol configuration of DMRS symbol, each CDM group of the N CDM groups corresponds to 2 antenna ports. Wherein, the index of the antenna port can be represented by 1000+DMRS port index, and each CDM group of the N CDM groups corresponding to 2 antenna ports can also be described as each CDM group of the N CDM groups corresponding to 2 DMRS ports, or. For example, when N is 6, the 6 CDM groups are denoted as CDM group0~5, and CDM group0 corresponds to antenna port. In the case of double-symbol configuration of DMRS symbol, each CDM group of the N CDM groups corresponds to 4 antenna ports.

[0120] It can be understood that the content indicated by the first information can be sent by the same signaling or message, or can be sent by multiple signaling or messages respectively. The embodiment of the present application does not limit this. The possible implementation modes are exemplified as follows.

[0121] In a possible implementation, the network device can send fifth indication information to the terminal device to implement indication of N code division multiplexing (CDM) groups corresponding to the DMRS, i.e., the fifth indication information is used to indicate the N CDM groups corresponding to the DMRS. Optionally, the fifth indication information can include a value of the N or an index used to determine the value of the N. Optionally, the network device can carry the aforementioned fifth indication information in RRC signaling or DCI sent to the terminal device.

[0122] In a possible implementation, on the basis of the aforementioned existing table 1 or table 2, more possible numbers of CDM groups not carrying data and numbers of DMRS ports can be defined by using reserved bits in the table or adding new bit positions.

[0123] Taking N as 6, i.e., 6 CDM groups based on DMRS Type 1 are configured as an example, DMRS Type 1 supports a maximum of 12 antenna ports in single-symbol configuration, and indexes of the corresponding 12 DMRS ports are denoted as 0-11. The DMRS port with index 0 is simply referred to as P0, the DMRS port with index 1 is simply referred to as P1, and so on. The 12 antenna ports (or 12 DMRS ports) are divided into 6 CDM groups denoted as CDM group 0-CDM group 5. CDM group 0 corresponds to P0 and P1, CDM group 1 corresponds to P1 and P2, and so on, and CDM group 5 corresponds to P11 and P12. Table 5 adds and defines, on the basis of table 1, that the number of CDM groups not carrying data also includes 3, 4, 5, and 6, and the indexes of the corresponding DMRS ports.

[0124] Table 5

[0125] As shown in Table 5 above, in case that the value of the antenna port field is equal to 12, then the DMRS port(s) index includes 4 and 5, so that the antenna port index is determined as 1000+4 (i.e. 1004) and 1000+5 (i.e. 1005), and the number of CDM groups not carrying data is 3. In case that the value of the antenna port field is equal to 13, then the DMRS port(s) index includes 6, 7, 8 and 9, so that the antenna port index includes 1000+6 (i.e. 1006), 1000+7 (i.e. 1007), 1000+8 (i.e. 1008) and 1000+9 (i.e. 1009), and the number of CDM groups not carrying data is 4, and so on. In addition, it can be understood that the correspondence between the number of CDM groups not carrying data and the DMRS port(s) in Table 5 above is only an example, and in actual application, other correspondence can also be used, for example, in case that the number of CDM groups not carrying data is 5 in Table 5, the DMRS port(s) index includes 8, 9, and in actual application, other indexes of the DMRS port(s) such as 6, 7, etc. can also be used, which is not limited in the embodiments of the present application.

[0126] In addition, it can be understood that, taking the number M of CDM groups not carrying data equal to 1 in Table 5 as an example, there is one CDM group among the 6 CDM groups not carrying data and only used for DMRS transmission, and there are 5 CDM groups among the 6 CDM groups that can be used to carry data and / or DMRS transmission.

[0127] Taking N as 6, i.e. taking the 6 CDM groups based on DMRS Type 1 as an example, DMRS Type 1 supports a maximum of 24 antenna ports in a double-symbol configuration, and the indexes of the corresponding DMRS ports are denoted as 0-23. The DMRS port with index 0 is simply referred to as P0, the DMRS port with index 1 is simply referred to as P1, and so on. The 24 antenna ports (or 24 DMRS ports) are divided into 6 CDM groups denoted as CDM group 0-CDM group 5. CDM group 0 corresponds to P0, P1, P12 and P13, CDM group 1 corresponds to P1, P2, P14 and P15, and so on, and CDM group 5 corresponds to P11, P12, P22 and P23. Table 6 adds definition of the number of CDM groups not carrying data including 3, 4, 5 and 6, and the indexes of the corresponding DMRS ports based on the reserved bits of the original value of Table 2.

[0128] Table 6

[0129] As shown in Table 6 above, in the case of using one codeword and the value of the antenna port field being equal to 31, the Number of front-load symbols is actually 2, the DMRS port(s) index includes 8-11, i.e. the index of the antenna port used for transmitting DMRS includes 1000+8 (i.e. 1008), 1000+9 (i.e. 1009), 1000+10 (i.e. 1010) and 1000+11 (i.e. 1011), and the number of CDM groups not carrying data is 3. In the case of using two codewords and the value of the antenna port field being equal to 7, the DMRS port(s) index includes 18-22, i.e. the index of the antenna port used for transmitting DMRS includes 1000+18 (i.e. 1018), 1000+19 (i.e. 1019), 1000+20 (i.e. 1020), 1000+21 (i.e. 1022) and 1000+22 (i.e. 1022), and the number of CDM groups not carrying data is 6, and so on. In addition, it can be understood that the correspondence between the number of CDM groups not carrying data and the DMRS port(s) in Table 6 above is only an example, and other correspondence can also be used in actual application, which is not limited by the embodiments of the present application.

[0130] In addition, it can be understood that, taking the number M of CDM groups not carrying data in Table 6 as an example, there are 2 CDM groups in the 6 CDM groups not carrying data and only used for DMRS transmission, and there are 4 CDM groups in the 6 CDM groups that can be used to carry data and / or DMRS transmission.

[0131] Based on the above definition, the network device can send the first information to the terminal device in the following manner: the network device sends the first indication information to the terminal device, the first indication information indicating the value of the number M of CDM groups not carrying data in the N CDM groups and the index of the antenna port used for transmitting DMRS. Optionally, the first indication information can be the value of the antenna port (antenna port(s)) field in the DCI, for example, in the case of N being 6 and single-symbol DMRS configuration, the first indication information corresponds to the value in Table 5, the value range being 0-15. For example, in the case of N being 6, double-symbol DMRS configuration and using one codeword, the first indication information corresponds to the value in Table 6, the value range being 0-31. For another example, in the case of N being 6, double-symbol DMRS configuration and using two codewords, the first indication information corresponds to the value in Table 6, the value range being 0-8.

[0132] In an alternative implementation, new indication information can be defined to indicate at least one second CDM group occupied by the DMRS in the N CDM groups, the corresponding antenna port of the at least one second CDM group including at least one antenna port used for transmitting the DMRS, i.e., the at least one antenna port used for transmitting the DMRS is in the at least one second CDM group; and new indication information can be defined to indicate the corresponding index of the at least one antenna port used for transmitting the DMRS in the corresponding antenna port of the at least one second CDM group; and new indication information can be defined to indicate the number M of CDM groups in the N CDM groups that do not carry data.

[0133] Some possible designs can be understood with reference to the following examples (1) to (3).

[0134] Example (1) defines second indication information to indicate at least one second CDM group occupied by the DMRS in the N CDM groups, the second CDM group referring to a CDM group in which the N CDM groups are used (i.e., used for transmitting the DMRS). Optionally, the second indication information can be carried in the DCI, occupying at least one bit of the DCI; or the second indication information can also be carried in the RRC signaling as a newly added field in the RRC signaling. Optionally, the number of bits occupied by the second indication information can be determined by the value of the aforementioned N.

[0135] For example, when N is 6, the 6 CDM groups are denoted as CDM group 0 to CDM group 5, the number of bits occupied by the second indication information can be 6, and the at least one second CDM group occupied by the DMRS is indicated based on a bit mapping manner, for example, the second indication information is 010000, indicating that the DMRS occupies one second CDM group in the 6 CDM groups, i.e., CDM group 1, and for another example, the second indication information is 000011, indicating that the DMRS occupies two second CDM groups in the 6 CDM groups, including CDM group 4 and CDM group 5.

[0136] For example, when N is 12, the 12 CDM groups are denoted as CDM group 0 to CDM group 11, the number of bits occupied by the second indication information can be 12, and the at least one second CDM group occupied by the DMRS is indicated based on a bit mapping manner, for example, the second indication information is 010000000000, indicating that the DMRS occupies one second CDM group in the 12 CDM groups, i.e., CDM group 1, and for another example, the second indication information is 000011000000, indicating that the DMRS occupies two second CDM groups in the 12 CDM groups, including CDM group 4 and CDM group 5.

[0137] For example, when N is 24, the 24 CDM groups are denoted as CDM group 0~CDM group 23, the second indication information occupies 24 bits, and the at least one second CDM group occupied by the DMRS is indicated based on the bit mapping manner. For example, the second indication information is 010000000000000000000000, indicating that the DMRS occupies one second CDM group, i.e., CDM group 1, among the 24 CDM groups. For another example, the second indication information is 000011000000000000, indicating that the DMRS occupies two second CDM groups, i.e., CDM group 4 and DM group 5, among the 24 CDM groups.

[0138] It can be understood that the mapping relationship between the number of bits occupied by the second indication information and the usage of the CDM groups is only an example, and the embodiments of the present application are not limited thereto.

[0139] Example (2) defines the third indication information to indicate the index of the antenna port used for transmitting the DMRS in the at least one second CDM group, i.e., the usage of the antenna port in the second CDM group. Optionally, the third indication information can be carried in the DCI, occupying at least one bit of the DCI; or the third indication information can also be carried in the RRC signaling as a newly added field in the RRC signaling.

[0140] Optionally, since the corresponding relationship between the CDM group and the antenna port is different under the single-symbol configuration and the double-symbol configuration, the network device can also add information for indicating the single-symbol configuration or the double-symbol configuration in the RRC signaling to indicate the terminal device to parse the third indication information in combination with the single-symbol configuration or the double-symbol configuration. Optionally, the network device can also add 1 bit for indicating the single-symbol configuration or the double-symbol configuration in the DCI, so that the terminal device can parse the third indication information in combination with the parameters related to the single-symbol configuration when the 1 bit in the DCI indicates the single-symbol configuration, or parse the third indication information in combination with the parameters related to the double-symbol configuration when the 1 bit in the DCI indicates the double-symbol configuration.

[0141] Taking the single-symbol configuration as an example, when 1 CDM group (i.e., one second CDM group) is used, the third indication information occupies 2 bits in the DCI, and the value of the 2 bits indicates the antenna port used in the aforementioned 1 CDM group; when 2 CDM groups are used, the third indication information occupies 4 bits in the DCI, and the value of the 4 bits indicates the antenna port used in the aforementioned 2 CDM groups, and so on.

[0142] For example, Table 7-1 shows that the second indication information indicates that the DMRS occupies CDM group 0, and the two antenna ports included in the CDM group 0 correspond to DMRS port 0 and DMRS port 1. The 2 bits of value occupied by the third indication information include 0, 1, 2, and 3. When the value is 0, it is used to indicate that the antenna port 1000 corresponding to the DMRS port 0 is used; when the value is 1, it is used to indicate that the antenna port 1001 corresponding to the DMRS port 1 is used; and when the value is 2, it is used to indicate that the antenna port 1000 corresponding to the DMRS port 0 and the antenna port 1001 corresponding to the DMRS port 1 are used.

[0143] Table 7-1

[0144] Similarly, for example, Table 7-2 shows that the second indication information indicates that the DMRS occupies CDM group 1, and the two antenna ports included in the CDM group 1 correspond to DMRS port 2 and DMRS port 3. The 2 bits of value occupied by the third indication information include 0, 1, 2, and 3. When the value is 0, it is used to indicate that the antenna port 1002 corresponding to the DMRS port 2 is used; when the value is 1, it is used to indicate that the antenna port 1003 corresponding to the DMRS port 3 is used; and when the value is 2, it is used to indicate that the antenna port 1002 corresponding to the DMRS port 2 and the antenna port 1003 corresponding to the DMRS port 3 are used.

[0145] Table 7-2

[0146] It can be understood that the mapping relationship between the number of bits occupied by the third indication information and the use of the antenna port in the CDM group is only an example, and the embodiments of the present application are not limited thereto.

[0147] Taking the case of using one code word in a dual-symbol configuration, when 1 CDM group (i.e., one second CDM group) is used, the third indication information occupies 4 bits in the DCI, and the 4 bits of value indicate the antenna port used in the aforementioned 1 CDM group.

[0148] For example, as shown in Table 8-1, the second indication information indicates that the DMRS occupies CDM group 0, and the four antenna ports included in the CDM group 0 correspond to DMRS port 0, DMRS port 1, DMRS port 12 and DMRS port 13. The four bits of the value occupied by the third indication information include 0-15, and value 0 is used to indicate the use of the antenna port 1000 corresponding to the DMRS port 0, value 1 is used to indicate the use of the antenna port 1001 corresponding to the DMRS port 1, and so on, and value 15 is used to indicate the use of the antenna port 1000 corresponding to the DMRS port 0, the antenna port 1001 corresponding to the DMRS port 1, the antenna port 1012 corresponding to the DMRS port 12 and the antenna port 1013 corresponding to the DMRS port 13.

[0149] Table 8-1

[0150] For example, as shown in Table 8-2, the second indication information indicates that the DMRS occupies CDM group 1, and the four antenna ports included in the CDM group 1 correspond to DMRS port 2, DMRS port 3, DMRS port 14 and DMRS port 15. The four bits of the value occupied by the third indication information include 0-15, and value 0 is used to indicate the use of the antenna port 1002 corresponding to the DMRS port 2, and so on.

[0151] Table 8-2

[0152] Example (3) defines the fourth indication information for indicating the number M of the CDM groups which do not carry data in the at least one CDM group. Optionally, the fourth indication information can be carried in the DCI; or, the fourth indication information can also be carried in the RRC signaling as a newly added field in the RRC signaling. Optionally, the number of bits occupied by the fourth indication information is determined by the value of N.

[0153] For example, when N is 6, the value of M is an integer from 1 to 6, and the fourth indication information can occupy 3 bits in the DCI. As shown in Table 9, the first 6 values (0-5) of the 3 bits correspond to the indication of the value of M, respectively.

[0154] Table 9

[0155] For example, when N is 12, the value of M is an integer from 1 to 12, and the fourth indication information can occupy 4 bits in the DCI. As shown in Table 10-1, the first 12 values (0-11) of the 3 bits correspond to the indication of the value of M, respectively.

[0156] Table 10-1

[0157] For example, when N is 24, M is an integer from 1 to 24, and the fourth indication information can occupy 5 bits in the DCI. As shown in Table 10-2, the first 24 values (0-23) of the 3 bits correspond to the values of M respectively.

[0158] Table 10-2

[0159] It can be understood that the mapping relationship between the number of bits occupied by the fourth indication information and the number M of CDM groups not carrying data is only an example, and embodiments of the present application are not limited thereto.

[0160] In addition, the newly added value of the number M of CDM groups not carrying data can also add the corresponding power scaling factor. Taking DMRS configuration type 1 as an example: Table 11 shows the power scaling factor corresponding to each value of M when N is 6 and M is an integer from 1 to 6. Table 12 shows the power scaling factor corresponding to each value of M when N is 12 and M is an integer from 1 to 12. Table 13 shows the power scaling factor corresponding to each value of M when N is 24 and M is an integer from 1 to 24.

[0161] Table 11

[0162] Table 12

[0163] Table 13

[0164] Based on the design of the above power scaling factor, in one possible implementation, after receiving the first information, the terminal device can calculate the power scaling factor corresponding to the DMRS according to the value of M indicated in the first information In another possible implementation, the terminal device can determine the power scaling factor corresponding to the DMRS by querying the above-mentioned Table 11, Table 12 or Table 13 according to the values of N and M indicated by the network device. In addition, the network device can also carry the power scaling factor corresponding to the value of M in the first information, and the terminal device does not need to determine it by itself, and embodiments of the present application are not limited thereto.

[0165] S302, the network device sends the DMRS to the terminal device according to the first information.

[0166] Firstly, the network device can determine resource mapping of the N CDM groups corresponding to the DMRS in combination with the first information. For example, the N CDM groups include at least one first CDM group, and any two of the m groups of REs corresponding to the first CDM group are different (or spaced) by at least N-1 subcarriers in the frequency domain. Wherein, m is an integer greater than or equal to 2.

[0167] In a possible implementation, the first CDM group refers to any one of the N CDM groups, that is, each of the N CDM groups corresponds to m groups of REs, and any two of the m groups of REs are different (or spaced) by at least N-1 subcarriers in the frequency domain. In this implementation, the number of first CDM groups is N. In another possible implementation, the first CDM group refers to the CDM group actually occupied by the DMRS, and the at least one first CDM group indicates that the number of CDM groups actually occupied by the DMRS is at least one.

[0168] In a possible implementation, the m groups of REs can be different (or spaced) by at least N-1 subcarriers in the frequency domain, which can include that any two adjacent groups of REs in the m groups of REs are different (or spaced) by N-1 subcarriers in the frequency domain. For example, when m is equal to 2, any two groups of REs are different (or spaced) by N-1 subcarriers in the frequency domain. For example, when m is equal to 3, the first group of REs and the second group of REs in the three groups of REs are different (or spaced) by N-1 subcarriers in the frequency domain, and the second group of REs and the third group of REs are different (or spaced) by N-1 subcarriers in the frequency domain.

[0169] It can be understood that in a single symbol configuration scenario, each group of REs in the m groups of REs includes 1 RE, or it can also be understood that 1 group of REs in the m groups of REs refers to 1 RE. In a double symbol configuration scenario, each group of REs in the m groups of REs includes 2 REs, and the 2 REs occupy different time symbols and the same subcarriers. In addition, optionally, I represents an integer greater than 2, and in an I symbol configuration scenario, each group of REs in the m groups of REs includes I REs, and the I REs occupy different time symbols and the same subcarriers. Wherein, the time symbol can be the aforementioned OFDM symbol, which is referred to as symbol hereinafter.

[0170] For ease of implementation, the following will be described by taking an example of each of the N CDM groups corresponding to 2 groups of REs.

[0171] In the single-symbol configuration scenario, one group of REs includes one RE, each of the N CDM groups corresponds to two REs, and all REs corresponding to the N CDM groups occupy the same symbol and different subcarriers. The two REs corresponding to the same CDM group are different by consecutive N-1 subcarriers in the frequency domain. For example, in the double-symbol configuration scenario, one group of REs includes two REs, and the two REs occupy different symbols and the same subcarriers. The time domain resources occupied by one group of REs include two symbols. Two groups of REs corresponding to each of the N CDM groups occupy the same time domain resources and different subcarriers. The two groups of REs corresponding to the same CDM group are different by consecutive N-1 subcarriers in the frequency domain.

[0172] Exemplarily, FIG. 4A shows that, in the case of N being 6 and the single-symbol configuration, six CDM groups (denoted as C0-C5) are mapped to at least one RB, and the RB includes 12 REs, different REs occupy the same symbol and different subcarriers. Each of the six CDM groups corresponds to two REs in the RB, and the two REs corresponding to the same CDM group are different by consecutive 5 subcarriers in the frequency domain, or it is understood that the difference between the indexes of the subcarriers of the two REs corresponding to the same CDM group is 6. FIG. 4A also shows that the six CDM groups correspond to 12 antenna ports (denoted as P0-P11), and each CDM group corresponds to two antenna ports, i.e., C0 corresponds to P0 and P1, C1 corresponds to P2 and P3, and so on. FIG. 4B shows that, in the case of N being 6 and the double-symbol configuration, six CDM groups are mapped to at least two RBs, and the two RBs occupy two symbols and 12 subcarriers. Two groups of REs corresponding to each of the six CDM groups occupy the same time domain resources and different subcarriers, and the time domain resources include the two symbols occupied by the two RBs. The two groups of REs corresponding to the same CDM group are different by consecutive 5 subcarriers in the frequency domain, or it is understood that the difference between the indexes of the subcarriers occupied by the two groups of REs is 12. FIG. 4B also shows that the six CDM groups correspond to 24 antenna ports, and each CDM group corresponds to four antenna ports, i.e., C0 corresponds to P0, P1, P12, and P13, C1 corresponds to P2, P3, P14, and P15, and so on.

[0173] Exemplarily, FIG. 5A schematically shows that, in the case of N being 12 and single-symbol configuration, 12 CDM groups (denoted as C0-C11) are mapped onto at least 2 RBs, the 2 RBs totally containing 24 REs, different REs occupying the same symbol and different subcarriers. Each of the 12 CDM groups corresponds to 2 REs in the 2 RBs, and the 2 REs corresponding to the same CDM group are different by 11 consecutive subcarriers in the frequency domain, or it is understood that the difference between the indexes of the subcarriers occupied by the 2 REs corresponding to the same CDM group is 12. FIG. 5A also schematically shows that the 12 CDM groups correspond to 24 antenna ports (denoted as P0-P23), wherein each CDM group corresponds to 2 antenna ports, i.e., C0 corresponds to P0 and P1, C1 corresponds to P2 and P3, and so on. FIG. 5B schematically shows that, in the case of N being 12 and double-symbol configuration, 12 CDM groups are mapped onto at least 4 RBs, the 4 RBs occupying two symbols and 24 subcarriers. Each of the 12 CDM groups corresponds to 2 groups of REs occupying the same time domain resource and different subcarriers, the time domain resource including the two symbols occupied by the aforementioned 4 RBs, and the 2 groups of REs corresponding to the same CDM group are different by 11 consecutive subcarriers in the frequency domain, or it is understood that the difference between the indexes of the subcarriers occupied by the 2 groups of REs is 12. FIG. 5B also schematically shows that the 12 CDM groups correspond to 48 antenna ports, wherein each CDM group corresponds to 4 antenna ports, i.e., C0 corresponds to P0, P1, P24 and P25, C1 corresponds to P2, P3, P26 and P27, and so on.

[0174] For example, FIG. 6A illustrates that, in the case of N being 24 and single-symbol configuration, 24 CDM groups (denoted as C0-C23) are mapped onto at least 4 RBs, which contain 48 REs in total, different REs occupying the same symbol and different subcarriers. Each of the 24 CDM groups corresponds to 2 REs in the 4 RBs, and the 2 REs corresponding to the same CDM group are different by 23 consecutive subcarriers in the frequency domain, or it can be understood that the difference between the indexes of the subcarriers occupied by the 2 REs corresponding to the same CDM group is 24. FIG. 6A also illustrates that 12 CDM groups correspond to 24 antenna ports (denoted as P0-P23), where each CDM group corresponds to 2 antenna ports, i.e., C0 corresponds to P0 and P1, C1 corresponds to P2 and P3, and so on. FIG. 6B illustrates that, in the case of N being 24 and double-symbol configuration, 24 CDM groups are mapped onto at least 8 RBs, which occupy two symbols and 48 subcarriers. Each of the 24 CDM groups corresponds to 2 groups of REs, which occupy the same time domain resource and different subcarriers, the time domain resource including the two symbols occupied by the aforementioned 8 RBs, and the 2 groups of REs corresponding to the same CDM group are different by 23 consecutive subcarriers in the frequency domain, or it can be understood that the difference between the indexes of the subcarriers occupied by the 2 groups of REs is 24. FIG. 6B also illustrates that 24 CDM groups correspond to 96 antenna ports, where each CDM group corresponds to 4 antenna ports, i.e., C0 corresponds to P0, P1, P48 and P49, C1 corresponds to P2, P3, P50 and P51, and so on.

[0175] Further, the network device can determine the time-frequency resource actually transmitting the DMRS in the resource mapping pattern corresponding to the DMRS according to the index of the antenna port transmitting the DMRS. For example, the antenna port transmitting the DMRS includes the antenna port corresponding to the ith CDM group in the N CDM groups, and the time-frequency resource of the DMRS includes the RE corresponding to the ith CDM group. Wherein, i is an integer less than or equal to N. In a possible implementation, the index k of the subcarrier of the RE corresponding to the ith CDM group in the N CDM groups satisfies the following formula: k = m x N x n + N x k' + Δ; wherein, n is an integer, for example, the value of n is determined according to the number R rb of RBs configured for PDSCH and the value of N, R rb is a positive integer, and n takes an integer from 0 to . The value of Δ is determined according to the index of the antenna port transmitting the DMRS, for example, according to the index of the antenna port transmitting the DMRS, it is determined that the antenna port corresponding to the ith CDM group includes the antenna port transmitting the DMRS, and then the value of Δ can be the index of the ith CDM group in the N CDM groups. For example, the indexes of the N CDM groups are numbered from 0 to N-1, and the index of the ith CDM group in the N CDM groups is i-1.

[0176] The network device can also define the antenna port p j and the subcarrier spacing μ, according to the aforementioned formula (1) The resource mapping of the DMRS is understood. Wherein, The value of can be understood according to the description in S301.

[0177] w f k' = 0, 1, l' = 0, 1 in w t To facilitate implementation, Table 14 provided by an embodiment of the present application shows an OCC mapping table under DMRS Type1 configuration. The OCC mapping table shown in Table 14 can be applied to N = 6, that is, the scenario of DMRS based on Type 1 of 6 CDM groups.

[0178] Table 14

[0179] Table 15 provided by an embodiment of the present application shows an OCC mapping table under DMRS Type1 configuration. The OCC mapping table shown in Table 15 can be applied to N = 12, that is, the scenario of DMRS based on Type 1 of 12 CDM groups.

[0180] Table 15

[0181] Table 16 provided by an embodiment of the present application shows an OCC mapping table under DMRS Type1 configuration. The OCC mapping table shown in Table 16 can be applied to N = 24, that is, the scenario of DMRS based on Type 1 of 24 CDM groups.

[0182] Table 16

[0183] It can be understood that the DMRS in S302 can also be understood as PDSCH DMRS, that is, S302 takes the network device sending PDSCH DMRS to the terminal device as an example for description. Similarly, the manner of the terminal device sending DMRS to the network device, that is, PUSCH DMRS, can be understood according to the above-mentioned scheme, and the embodiments of the present application do not make redundant description here.

[0184] S303, the terminal device receives the DMRS and performs channel estimation according to the first information.

[0185] Corresponding to the description in S301 and S302, the terminal device can determine the time-frequency resource, the power scaling factor and the time-frequency domain OCC of the DMRS according to the first information, and then receive the DMRS on the time-frequency resource of the DMRS according to the power scaling factor and the time-frequency domain OCC. This step can be implemented by referring to the parameter correspondence in the table defined in S301 and S302, and the embodiments of the present application do not repeat it. Further, the terminal device can use the DMRS to perform channel estimation of the PDSCH.

[0186] The above communication method can reduce the interference of the DMRS on data transmission by redesigning the resource mapping pattern of the N (greater than 2) CDM groups corresponding to the DMRS on the time-frequency resource, increasing the number of CDM groups and the sparsity of the DMRS occupied resource, and reducing the RE occupied by the CDM group transmitting the DMRS; in addition, transmitting data by using the RE occupied by the CDM group other than the CDM group transmitting the DMRS can increase the data transmission resource, thereby improving the data transmission performance.

[0187] The embodiments of the present application also provide another communication method, which is based on the scheme described in FIG. 3, introduces the capability reporting of the terminal device, in the case that the terminal device supports the DMRS based on Type1 N CDM groups, the network side performs the parameter configuration of the DMRS described in FIG. 3, which can ensure the normal implementation of the scheme, and enhance the selectability of the terminal device, and determine whether to activate the parameter configuration of the DMRS, which can also improve the flexibility of the implementation of the scheme.

[0188] Exemplarily, as shown in FIG. 7, the another communication method mainly includes the following steps.

[0189] S701, the network device sends third information to the terminal device.

[0190] The third information is used to request the support capability of the terminal device for the CDM group under DMRS Type1, and the third information can also be replaced by request information or capability request information, and the embodiments of the present application do not limit it. For example, the third information carries the value of the foregoing N (for example, 6, 12, 24) to request whether the terminal device has the capability to support the DMRS based on Type1 N CDM groups. For another example, the third information does not carry the value of the foregoing N, and the first capability request message is used to request the terminal device to support the number of CDM groups under DMRS Type1.

[0191] Optionally, the third information can be a newly added radio resource control (radio resource control, RRC) signaling or a newly added field in the RRC signaling, or the third information can be a newly added field in the DCI.

[0192] S702, the terminal device sends second information to the network device.

[0193] The second information is used to indicate that the terminal device supports a quantity of CDM groups of DMRS as the N, or can be alternatively described as the second information being used to indicate that the terminal device supports a quantity of CDM groups of DMRS Type 1 as the N.

[0194] In a possible design, S702 is executed after S701, the second information can be regarded as a response to the third information, and the second information can be alternatively described as response information or capability response information of the third information, which is not limited by embodiments of the present application. In another possible design, S701 can not be executed, and S702 is directly executed, that is, in this design, the terminal device actively reports its support capability of the quantity of CDM groups of DMRS Type 1 to the terminal device. Based on this, it can be understood that S701 is an optional step, and S701 is shown in a dashed line in FIG. 7.

[0195] Exemplarily, corresponding to a case that the third information carries the value of N, the second information can use 1 bit to indicate whether the terminal device has the capability of supporting N CDM groups of DMRS based on Type 1. For example, the 1 bit corresponding to the second information takes a value of 0, indicating that the terminal device does not have the capability of supporting N CDM groups of DMRS based on Type 1, and the 1 bit corresponding to the second information takes a value of 1, indicating that the terminal device has the capability of supporting N CDM groups of DMRS based on Type 1. In a possible implementation, when the third information carries the value of N, and the terminal device does not have the capability of supporting N CDM groups of DMRS based on Type 1, the terminal device can also carry the value of N' in the second information, indicating that the terminal device has the capability of supporting N' CDM groups of DMRS based on Type 1. For example, the value of N carried in the third information is 24, and the terminal device only supports 6 CDM groups of DMRS based on Type 1, and the terminal device carries the value of N' in the second information as 6.

[0196] Exemplarily, corresponding to a case that the third information does not carry the value of N, the terminal device can carry the value of N or an index capable of indicating the value of N in the second information, indicating that the terminal device has the capability of supporting N CDM groups of DMRS based on Type 1.

[0197] Optionally, the second information can be newly added RRC signaling or a newly added field in RRC signaling, or the second information can be a newly added field in uplink control information (UCI).

[0198] S703, the network device sends the first information to the terminal device.

[0199] This step can be implemented with reference to the description in S301, and the embodiments of the present application do not perform the description.

[0200] Taking the terminal device with the capability of Type 1 based N CDM group DMRS as an example, it can be understood that the network device performing S703 can implicitly indicate the terminal device to activate the Type 1 based N CDM group DMRS capability. In addition, the network device can also carry a flag in the first information, and the flag takes a value of 1, which is used to directly indicate the terminal device to activate the Type 1 based N CDM group DMRS capability.

[0201] S704, the network device sends the DMRS to the terminal device according to the first information.

[0202] This step can be implemented with reference to the description in S302, and the embodiments of the present application do not perform the description.

[0203] S705, the terminal device receives the DMRS and performs channel estimation according to the first information.

[0204] This step can be implemented with reference to the description in S303, and the embodiments of the present application do not perform the description.

[0205] Based on the same concept, referring to FIG. 8, the embodiments of the present application provide a communication device 800, which includes a processing module 801 and a communication module 802. The communication device 800 can be a network device, or can be applied to the network device or matched with the network device, and can be a communication device capable of implementing the communication method executed by the network device side; or the communication device 800 can be a terminal device, or can be applied to the terminal device or matched with the terminal device, and can be a communication device capable of implementing the communication method executed by the terminal device side.

[0206] The communication module can also be referred to as a transceiver module, a transceiver, a transceiver, or a transceiver device. The processing module can also be referred to as a processor, a processing board, a processing unit, or a processing device. Optionally, the communication module is used to execute the sending operation and the receiving operation of the network device side or the terminal device side in the above method, and the device in the communication module for realizing the receiving function can be regarded as a receiving unit, and the device in the communication module for realizing the sending function can be regarded as a sending unit, that is, the communication module includes a receiving unit and a sending unit.

[0207] The communication apparatus 800, when applied to a network device, the processing module 801 can be configured to implement the processing function of the network device in the embodiments shown in FIG. 3 or FIG. 7, and the communication module 802 can be configured to implement the transceiving function of the network device in the embodiments shown in FIG. 3 or FIG. 7.

[0208] The communication apparatus 800, when applied to a terminal device, the processing module 801 can be configured to implement the processing function of the terminal device in the embodiments shown in FIG. 3 or FIG. 7, and the communication module 802 can be configured to implement the transceiving function of the terminal device in the embodiments shown in FIG. 3 or FIG. 7.

[0209] In addition, it should be noted that the aforementioned communication module and / or processing module can be implemented by a virtual module, for example, the processing module can be implemented by a software function unit or a virtual device, and the communication module can be implemented by a software function or a virtual device. Alternatively, the processing module or the communication module can also be implemented by an entity device, for example, if the communication apparatus is implemented by a chip / chip circuit, the communication module can be an input / output circuit and / or a communication interface, which performs an input operation (corresponding to the aforementioned receiving operation) and an output operation (corresponding to the aforementioned sending operation); and the processing module is an integrated processor or a microprocessor or an integrated circuit.

[0210] The division of the modules in the embodiments of the present application is illustrative, and is only a logical function division. In actual implementation, another division manner can be used. In addition, each function module in each embodiment of the present application can be integrated in one processor, or can be physically separated, or two or more modules can be integrated in one module. The integrated module can be implemented in the form of hardware or in the form of a software function module.

[0211] Based on the same technical concept, the embodiments of the present application further provide a communication apparatus 900. For example, the communication apparatus 900 can be a chip or a chip system. Optionally, in the embodiments of the present application, the chip system can be composed of a chip, or can include a chip and other discrete devices.

[0212] The communication apparatus 900 can be configured to implement the function of any terminal device in the communication system described in the foregoing embodiments. The communication apparatus 900 can include at least one processor 910 coupled with a memory. Optionally, the memory can be located in the communication apparatus, and can be integrated with the processor, or can be located outside the communication apparatus. For example, the communication apparatus 900 can further include at least one memory 920. The memory 920 stores necessary computer programs, computer programs or instructions and / or data for implementing any of the foregoing embodiments. The processor 910 can execute the computer programs stored in the memory 920 to complete the method in any of the foregoing embodiments.

[0213] The communication device 900 can further include a communication interface 930, through which the communication device 900 can exchange information with other devices. For example, the communication interface 930 can be a transceiver, a circuit, a bus, a module, a pin, or another type of communication interface. When the communication device 900 is a chip-type device or a circuit, the communication interface 930 in the communication device 900 can also be an input-output circuit that can input (or receive) information and output (or send) information. The processor can be an integrated processor or a microprocessor or an integrated circuit or a logic circuit. The processor can determine output information according to input information.

[0214] The coupling in the embodiments of the present application is indirect coupling or communication connection between devices, units or modules, which can be electrical, mechanical or other forms, and is used for information interaction between devices, units or modules. The processor 910 can operate in cooperation with the memory 920 and the communication interface 930. The specific connection medium between the processor 910, the memory 920 and the communication interface 930 is not limited in the embodiments of the present application.

[0215] Optionally, as shown in FIG. 9, the processor 910, the memory 920 and the communication interface 930 are connected to each other through a bus 940. The bus 940 can be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus, etc. The bus can be divided into an address bus, a data bus, a control bus, etc. For the convenience of representation, only one thick line is shown in FIG. 9, but it does not mean that there is only one bus or only one type of bus.

[0216] In the embodiments of the present application, the processor can be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, and can implement or execute the disclosed methods, steps and logic block diagrams in the embodiments of the present application. The general-purpose processor can be a microprocessor or any conventional processor, etc. The steps of the method disclosed in conjunction with the embodiments of the present application can be directly embodied as execution completed by a hardware processor, or executed by a combination of hardware and software modules in the processor.

[0217] In the embodiments of the present application, the memory can be a non-volatile memory, such as a hard disk drive (HDD) or a solid-state drive (SSD), and can also be a volatile memory, such as a random-access memory (RAM). The memory can be any other medium capable of carrying or storing desired program codes in the form of instructions or data structures and capable of being accessed by a computer, but is not limited to this. The memory in the embodiments of the present application can also be a circuit or any other device capable of realizing a storage function, for storing program instructions and / or data.

[0218] In a possible implementation, the communication apparatus 900 can be applied to a network device (such as a first network device or a second network device), and specifically, the communication apparatus 900 can be a network device or a device capable of supporting a network device and realizing the functions of the network device in any of the above-described embodiments. The memory 920 stores computer programs (or instructions) and / or data for realizing the functions of the network device in any of the above-described embodiments. The processor 910 can execute the computer programs stored in the memory 920 to complete the methods performed by the network device in any of the above-described embodiments. When applied to a network device, the communication interface in the communication apparatus 900 can be used to interact with a terminal device, send information to the terminal device, or receive information from the terminal device.

[0219] In another possible implementation, the communication apparatus 900 can be applied to a terminal device, and specifically, the communication apparatus 900 can be a terminal device or a device capable of supporting a terminal device and realizing the functions of the terminal device in any of the above-described embodiments. The memory 920 stores computer programs (or instructions) and / or data for realizing the functions of the terminal device in any of the above-described embodiments. The processor 910 can execute the computer programs stored in the memory 920 to complete the methods performed by the terminal device in any of the above-described embodiments. When applied to a terminal device, the communication interface in the communication apparatus 900 can be used to interact with a network device, send information to the network device, or receive information from the network device.

[0220] Since the communication apparatus 900 provided in the embodiments can be applied to a network device to complete the methods performed by the network device, or applied to a terminal device to complete the methods performed by the terminal device, the technical effects that can be achieved thereby can refer to the above method examples, which will not be described herein again.

[0221] Based on the same idea, the embodiments of the present application also provide a baseband chip which can be applied to the terminal device or the network device. As shown in FIG. 10, the baseband can be implemented by a processing system including one or more processors. The processor includes a microprocessor (such as X86, ARM), a microcontroller, a digital signal processor (DSP), a field programmable gate array (FPGA), a graphics processing unit (GPU), a programmable logic device (PLD), a state machine, a gate logic, a discrete hardware circuit, and other suitable hardware configured to perform various functions. That is, the processor used in the baseband can be used to implement the processes and any one or more of the processes described below.

[0222] The processing system can be implemented with a bus architecture, generally represented by the bus. The bus can include any number of interconnecting buses and bridges, depending on the specific application of the processing system and the overall design constraints. The bus communicatively couples various circuitry including one or more processors, memory, and one or more computer-readable media. Among others, the plurality of processors are represented by “L” in FIG. 10, and the computer-readable media are represented by “L” in FIG. 10. The bus can also link various other circuitry, such as a timing source, peripherals, voltage regulators, and power management circuitry, which are well-known in the art and thus, will not be further described. A bus interface provides an interface between the bus and a transceiver, and between the bus and an interface.

[0223] The transceiver provides a communication interface or means for communicating with various other apparatus over the wireless transmission medium. The transceiver can be coupled to an antenna array, and the transceiver and the antenna array can be used together to communicate with a corresponding network type. At least one interface (e.g., a network interface and / or a user interface) provides a communication interface or means for communicating over the internal bus or via an external transmission medium.

[0224] The processor is responsible for managing the bus and general processing, including the execution of software stored on the computer-readable medium. The software, when executed by the processor, causes the processing system to perform the various functions described below for any particular apparatus.

[0225] The functions that the processor and the memory and the computer readable medium can implement can be encoding, decoding, rate matching, de-rate matching, scrambling, descrambling, modulation, demodulation, layer mapping, fast fourier transform (FFT), inverse fast fourier transform (IFFT), inverse discrete fourier transform (IDFT), precoding, RE mapping, channel equalization, de-RE mapping, digital beam forming (BF), adding a cyclic prefix (CP), removing a CP, and the like.

[0226] Based on the above embodiments, the embodiments of the present application provide a communication system, including a network device and a terminal device, wherein the network device and the first terminal device can implement the method provided in the embodiments shown in FIG. 3 or FIG. 7.

[0227] The technical solutions provided in the embodiments of the present application can be implemented all or partially by software, hardware, firmware or any combination thereof. When implemented by software, the technical solutions can be implemented in the form of a computer program product all or partially. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated all or partially. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a first terminal device, a network device or other programmable apparatus. The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through wired (for example, coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (for example, infrared, wireless, microwave, etc.) manner. The computer readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more available medium sets. The available medium can be a magnetic medium (for example, floppy disk, hard disk, magnetic tape), an optical medium (for example, digital video disc (DVD)), or a semiconductor medium, etc.

[0228] In the embodiments of the present application, under the premise of no logical contradiction, the embodiments can be referred to each other, for example, the methods and / or terms between the method embodiments can be referred to each other, for example, the functions and / or terms between the device embodiments can be referred to each other, for example, the functions and / or terms between the device embodiments and the method embodiments can be referred to each other.

[0229] Obviously, various modifications and variations of the embodiments of the present application can be made by those skilled in the art without departing from the scope of the embodiments of the present application. Thus, it is intended that the embodiments of the present application include such modifications and variations as fall within the scope of the claims to the embodiments of the present application and their equivalents.

Claims

1. A communication method, characterized in that, Applied to terminal devices, including: The system receives first information, which indicates at least one of the following: N code division multiplexing (CDM) groups corresponding to the demodulation reference signal (DMRS), the number M of CDM groups that do not carry data among the N CDM groups, and the index of at least one antenna port among the antenna ports corresponding to the N CDM groups used for transmitting the DMRS; wherein the N CDM groups include at least one first CDM group, any first CDM group corresponds to m resource units (REs), and any two REs in the m REs differ from each other by at least N-1 subcarriers in the frequency domain; N is an integer greater than 2, M is a positive integer less than or equal to N, and m is an integer greater than or equal to 2; Based on the first information, the DMRS is transmitted.

2. The method as described in claim 1, characterized in that, Each of the m groups of REs includes one RE; or, Each of the m groups of REs includes at least two REs, the at least two REs occupying different time symbols, and the at least two REs occupying the same subcarrier.

3. The method as described in claim 1 or 2, characterized in that, The index of the subcarrier occupied by the m REs corresponding to the first CDM group is determined based on the value of N, the value of m, and the index of at least one antenna port used to transmit the DMRS.

4. The method according to any one of claims 1-3, characterized in that, Also includes: Based on the value of M, the power scaling factor corresponding to the DMRS is determined, and the power scaling factor corresponding to the DMRS is used to determine the transmission power of the DMRS.

5. The method as described in claim 4, characterized in that, When N is 6 and M is 1, 2, 3, 4, 5, 6, the power scaling factors corresponding to the DMRS are 0dB, -3dB, -4.77dB, -6dB, -6.99dB, and -7.78dB, respectively.

6. The method as described in claim 4, characterized in that, When N is 12 and M is an integer from 1 to 12 in ascending order, the power scaling factors corresponding to the DMRS are 0dB, -3dB, -4.77dB, -6.02dB, -6.99dB, -7.78dB, -8.45dB, -9.03dB, -9.54dB, -10dB, -10.4dB, and -10.79dB, respectively.

7. The method as described in claim 4, characterized in that, When N is 24 and M is an integer from 1 to 24 in ascending order, the power scaling factors corresponding to the DMRS are 0dB, -3dB, -4.77dB, -6.02dB, -6.99dB, -7.78dB, -8.45dB, -9.03dB, -9.54dB, -10dB, -10.4dB, -10.79dB, -11.14dB, -11.46dB, -11.76dB, -12.04dB, -12.30dB, -12.55dB, -12.79dB, -13.01dB, -13.22dB, -13.42dB, -13.62dB, and -13.8dB, respectively.

8. The method according to any one of claims 1-7, characterized in that, The receiving of the first information includes: Receive first indication information, which is used to indicate the number M of CDM groups that do not carry data among the N CDM groups, and the index of at least one antenna port among the antenna ports corresponding to the N CDM groups that is used to transmit the DMRS.

9. The method according to any one of claims 1-7, characterized in that, The receiving of the first information includes: Receive second indication information and third indication information, wherein the second indication information is used to indicate at least one second CDM group among the N CDM groups, and the third indication information is used to indicate the index of at least one antenna port for transmitting the DMRS in the antenna port corresponding to the at least one second CDM group; Receive fourth indication information, which is used to indicate the number M of CDM groups that do not carry data among the N CDM groups.

10. The method according to any one of claims 1-9, characterized in that, The receiving of the first information further includes: Receive fifth indication information, which is used to indicate the N code division multiplexing (CDM) groups corresponding to the DMRS.

11. The method according to any one of claims 1-10, characterized in that, Before receiving the first message, it also includes: Send a second message, which indicates that the terminal device supports the number of CDM groups corresponding to the DMRS as N.

12. A communication method, characterized in that, Applied to network devices, including: Send first information, which indicates at least one of the following: N code division multiplexing (CDM) groups corresponding to the demodulation reference signal (DMRS), the number M of CDM groups that do not carry data among the N CDM groups, and the index of at least one antenna port among the antenna ports corresponding to the N CDM groups used for transmitting the DMRS; wherein, the N CDM groups include at least one first CDM group, any first CDM group corresponds to m resource units (REs), and any two REs in the m REs are at least N-1 subcarriers apart in the frequency domain; N is an integer greater than 2, M is a positive integer less than or equal to N, and m is an integer greater than or equal to 2; Based on the first information, the DMRS is transmitted.

13. The method as described in claim 12, characterized in that, Each of the m groups of REs includes one RE; or, Each of the m groups of REs includes at least two REs, the at least two REs occupying different time symbols, and the at least two REs occupying the same subcarrier.

14. The method as described in claim 12 or 13, characterized in that, The index of the subcarrier occupied by the m REs corresponding to the first CDM group is determined based on the value of N, the value of m, and the index of at least one antenna port used to transmit the DMRS.

15. The method according to any one of claims 12-14, characterized in that, The number M of the N CDM groups that do not carry data is used to determine the power scaling factor corresponding to the DMRS, and the power scaling factor corresponding to the DMRS is used to determine the transmission power of the DMRS.

16. The method as described in claim 15, characterized in that, When N is 6 and M is 1, 2, 3, 4, 5, 6, the power scaling factors corresponding to the DMRS are 0dB, -3dB, -4.77dB, -6dB, -6.99dB, and -7.78dB, respectively.

17. The method as described in claim 15, characterized in that, When N is 12 and M is an integer from 1 to 12 in ascending order, the power scaling factors corresponding to the DMRS are 0dB, -3dB, -4.77dB, -6.02dB, -6.99dB, -7.78dB, -8.45dB, -9.03dB, -9.54dB, -10dB, -10.4dB, and -10.79dB, respectively.

18. The method as described in claim 15, characterized in that, When N is 24 and M is an integer from 1 to 24 in ascending order, the power scaling factors corresponding to the DMRS are 0dB, -3dB, -4.77dB, -6.02dB, -6.99dB, -7.78dB, -8.45dB, -9.03dB, -9.54dB, -10dB, -10.4dB, -10.79dB, -11.14dB, -11.46dB, -11.76dB, -12.04dB, -12.30dB, -12.55dB, -12.79dB, -13.01dB, -13.22dB, -13.42dB, -13.62dB, and -13.8dB, respectively.

19. The method according to any one of claims 12-18, characterized in that, The sending of the first information includes: Send a first indication message, which is used to indicate the number M of the N CDM groups that do not carry data, and the index of at least one antenna port in the antenna ports corresponding to the N CDM groups that is used to transmit the DMRS.

20. The method according to any one of claims 12-18, characterized in that, The sending of the first information includes: Send a second indication message and a third indication message, wherein the second indication message is used to indicate at least one second CDM group among the N CDM groups, and the third indication message is used to indicate the index of at least one antenna port for transmitting the DMRS in the antenna port corresponding to the at least one second CDM group; Send a fourth indication message, which is used to indicate the number M of CDM groups that do not carry data among the N CDM groups.

21. The method as described in claim 19 or 20, characterized in that, The sending of the first information also includes: Send a fifth indication message, which is used to indicate the N code division multiplexing (CDM) groups corresponding to the DMRS.

22. The method according to any one of claims 12-21, characterized in that, Before sending the first message, it also includes: The terminal device receives second information, which indicates that the number of CDM groups corresponding to the DMRS supported by the terminal device is N.

23. A communication device, characterized in that, It includes a module for performing the method as described in any one of claims 1-11, or includes a module for performing the method as described in any one of claims 12-22.

24. A communication device, characterized in that, include: A processor coupled to a memory, the processor being configured to invoke computer program instructions stored in the memory to perform the method as claimed in any one of claims 1-11, or to perform the method as claimed in any one of claims 12-22.

25. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1-22.

26. A computer program product, characterized in that, Includes computer execution instructions, which, when executed on a computer, cause the computer to perform the method as described in any one of claims 1-22.

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