Communication method and apparatus

Abstract

A communication method, which is applied to a first communication apparatus. The first communication apparatus may receive first indication information, which is used for indicating a first demodulation reference signal and a second demodulation reference signal, wherein the second demodulation reference signal is a zero-power demodulation reference signal with the power being 0. After receiving the first indication information, the first communication apparatus may send a first PUSCH to a second communication apparatus on the basis of the first indication information, wherein the first PUSCH carries the first demodulation reference signal and the second demodulation reference signal, and the first demodulation reference signal and the second demodulation reference signal are used for performing channel estimation. In the present application, in addition to carrying a first demodulation reference signal, a first PUSCH sent by a first communication apparatus further carries an additional second demodulation reference signal with the power being 0, such that a second communication apparatus can estimate, in view of a second PUSCH, the interference of a PUSCH from another device, thereby improving the precision of a second device performing channel estimation.

Description

A communication method and apparatus

[0001] The present application claims priority from the Chinese patent application No. 2024107085697 entitled "A communication method and apparatus" and filed with the State Intellectual Property Office of China on May 31, 2024, the contents of which are incorporated herein in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of wireless technology, and in particular, to a communication method and apparatus. BACKGROUND

[0003] Before devices communicate with each other, channel estimation can be performed so as to facilitate communication based on the result of channel estimation. In one example, device A can send a demodulation reference signal (DMRS) to device B, and correspondingly, device B can perform channel estimation based on the DMRS sent by device A. In multi-input multi-output (MIMO) technology, the aforementioned device A can be a terminal device, and device B can be a network device. The MIMO technology is a key technology in wireless communication, which can be used to meet the demand for high-speed transmission.

[0004] In some scenarios, there can be multiple devices A sending DMRS to device B, and correspondingly, device B can estimate the channel between itself and each device A based on the DMRS sent by each device A. For example, in a multi-user MIMO (MU-MIMO) scenario, multiple terminal devices can send DMRS to a network device respectively, and correspondingly, the network device can estimate the channel between itself and each terminal device based on the DMRS sent by each terminal device.

[0005] Since the DMRS sent by multiple devices A can interfere with each other, device B cannot accurately estimate the channel between itself and each device A. Therefore, there is an urgent need for a solution to solve the above problem. SUMMARY

[0006] Embodiments of the present application provide a communication method, which can improve the accuracy of channel estimation.

[0007] In a first aspect, this application provides a communication method, which can be applied, for example, to a first communication device, which is a terminal or a component (or device) within a terminal. The component in this application may include, for example, at least one of a chip, a chip system, a processor, a transceiver, a processing unit, a circuit, a functional module, or a transceiver unit. The first communication device can receive first indication information, which indicates a first demodulation reference signal and a second demodulation reference signal, wherein the second demodulation reference signal is a zero-power demodulation reference signal with zero power. After receiving the first indication information, a first physical uplink shared channel (PUSCH) can be sent to a second communication device according to the first indication information. The first PUSCH carries the aforementioned first and second demodulation reference signals, which are used for channel estimation. In this embodiment, the first PUSCH sent by the first communication device carries not only the first demodulation reference signal but also an additional second demodulation reference signal with zero power. This enables the second communication device to estimate interference from PUSCHs of other devices by combining the second PUSCH, thereby improving the accuracy of channel estimation by the second communication device.

[0008] In one possible implementation, the pattern of the second demodulation reference signal may be related to the first signal waveform corresponding to the first PUSCH. Therefore, in one example, the first indication information may include the first signal waveform, through which the pattern of the second demodulation reference signal is indicated.

[0009] In one possible implementation, if the first indication information includes a first signal waveform used to indicate the pattern of the second demodulation reference signal, then the first communication device can determine the pattern of the second demodulation reference signal based on a first correspondence between the signal waveform and the pattern and the first signal waveform. The first correspondence mentioned here may be a correspondence between an identifier of a signal waveform and a pattern identifier (e.g., a pattern index). The first correspondence may include multiple correspondences, at least including the correspondence between the first signal waveform and the pattern of the second demodulation reference signal.

[0010] In one possible implementation, the pattern of the second demodulation reference signal may be associated with a first sequence corresponding to the first demodulation reference signal (e.g., a pre-demodulation reference signal). Therefore, in one example, the first indication information may include the first sequence, through which the pattern of the second demodulation reference signal is indicated.

[0011] In one possible implementation, if the first indication information includes a first sequence indicating a pattern of the second demodulation reference signal, the first communication device can determine the pattern of the second demodulation reference signal based on a second correspondence between the sequence and the pattern and the first sequence. The second correspondence mentioned herein can be a correspondence between a sequence identifier and a pattern identifier (e.g., a pattern index). The second correspondence can include multiple correspondences, at least including the correspondence between the first sequence and the pattern of the second demodulation reference signal.

[0012] In one possible implementation, the pattern of the second demodulation reference signal may be related to both the aforementioned first signal waveform and the first sequence. In this case, the first indication information may include the first signal waveform and the first sequence, and the pattern of the second demodulation reference signal may be indicated by the first signal waveform and the first sequence.

[0013] In one possible implementation, if the first indication information includes a first signal waveform and a first sequence, wherein the first signal waveform and the first sequence are used to indicate the pattern of the second demodulation reference signal, then the first communication device can determine the pattern of the second demodulation reference signal based on a third correspondence between the signal waveform, the sequence, and the pattern, and the first signal waveform and the first sequence. The third correspondence mentioned herein can be a correspondence between the identifier of the signal waveform, the identifier of the sequence, and the identifier of the pattern. The third correspondence can include multiple correspondences, at least including the correspondence between the first signal waveform, the first sequence, and the pattern of the second demodulation reference signal.

[0014] In one possible implementation, the pattern index of the second demodulated reference signal can be used to determine the pattern of the second demodulated reference signal. Therefore, in one example, the first indication information includes the pattern index of the second demodulated reference signal, which indicates the pattern of the second demodulated reference signal.

[0015] In one possible implementation, the pattern of the second demodulated reference signal includes information on both time-domain and frequency-domain resources it occupies. As an example, the first indication information can indicate the time-domain resources occupied by the second demodulated reference signal. As another example, the time-domain resources occupied by the second demodulated reference signal can be indicated by the index of the orthogonal frequency division multiplexing (OFDM) symbols occupied by the second demodulated reference signal. Therefore, the first indication information can include the index of the OFDM symbols occupied by the second demodulated reference signal, which indicates the position of the OFDM symbols occupied by the second demodulated reference signal. As yet another example, the position of the OFDM symbols occupied by the second demodulated reference signal can be determined by the difference between the index of the OFDM symbols occupied by the first demodulated reference signal and the index of the OFDM symbols occupied by the second demodulated reference signal (referred to as the index difference). Therefore, the first indication information can include the index difference, which indicates the position of the OFDM symbols occupied by the second demodulated reference signal.

[0016] In one possible implementation, the frequency domain resources occupied by the second demodulation reference signal can be indicated by the first indication information. Specifically: if the frequency resources corresponding to the second demodulation reference signal are sparsely mapped onto the scheduling bandwidth, the location may include the starting frequency resource location and the sparse density; if the frequency resources corresponding to the second demodulation reference signal occupy at least one resource block on the scheduling bandwidth, the location includes at least two of the following: the starting location, the ending location, and the resource block size for each of the at least one resource block.

[0017] In one possible implementation, if the first signal waveform is a single-carrier waveform, the frequency resources corresponding to the second demodulation reference signal are thinned out and mapped onto the scheduling bandwidth to maintain a low peak-to-average power ratio for the low-carrier waveform. If the first signal waveform is a multi-carrier waveform, the frequency resources corresponding to the second demodulation reference signal occupy at least one resource block on the scheduling bandwidth, or the frequency resources corresponding to the second demodulation reference signal are thinned out and mapped onto the scheduling bandwidth.

[0018] In one possible implementation, if the frequency resources corresponding to the aforementioned second demodulation reference signal occupy at least one resource block on the scheduling bandwidth, then in one example, the at least one resource block can correspond one-to-one with at least one precoded subband precoded by the network device. In this way, when the second communication device evaluates interference from other terminal devices based on the second demodulation reference, it can estimate the interference from other terminal devices on each precoded subband.

[0019] In one possible implementation, the first demodulation reference signal includes: a pre-demodulation reference signal, or a pre-demodulation reference signal and an additional demodulation reference signal. That is, using this scheme, in addition to the pre-demodulation reference signal and the additional demodulation reference signal, a zero-power demodulation reference signal is introduced during channel estimation, thereby effectively improving the accuracy of signal estimation.

[0020] In one possible implementation, the first demodulation reference signal and the second demodulation reference signal need to have a certain degree of isolation, so that the network device can assess interference from other terminal devices based on the second demodulation reference signal. In a specific example, the first demodulation reference signal and the second demodulation reference signal are time-division multiplexed.

[0021] In one possible implementation, the non-demodulation reference signal carrier position on the OFDM symbol where the second demodulation reference signal is located is used to transmit user data, thereby effectively utilizing the resources of the first PUSCH.

[0022] Secondly, this application provides a communication method, which can be applied, for example, to a second communication device. The second communication device is a network device or a component (or apparatus) within a network device. The second communication device can send first indication information to a first communication device, the first indication information indicating a first demodulation reference signal and a second demodulation reference signal, wherein the second demodulation reference signal is a zero-power demodulation reference signal with zero power. The first communication device can be a terminal or a component within a terminal. Further, the second communication device receives a first PUSCH sent by the first communication device according to the first indication information. The first PUSCH carries the aforementioned first and second demodulation reference signals, which are used for channel estimation. In the embodiments of this application, the first PUSCH sent by the first communication device carries not only the first demodulation reference signal but also an additional second demodulation reference signal with zero power, thereby enabling the second communication device to estimate interference from PUSCHs of other terminal devices by combining the second PUSCH, thus improving the accuracy of channel estimation performed by the second communication device.

[0023] In one possible implementation, the first indication information includes: a first signal waveform corresponding to the first PUSCH and / or a first sequence corresponding to the first demodulation reference signal, wherein the first signal waveform and / or the first sequence are used to determine the pattern of the second demodulation reference signal.

[0024] In one possible implementation, the first indication information includes: a pattern index of the second demodulation reference signal, the pattern index of the second demodulation reference signal being used to determine the pattern of the second demodulation reference signal.

[0025] In one possible implementation, the first indication information includes: an index of the orthogonal frequency division multiplexing (OFDM) symbol occupied by the second demodulation reference signal; or, an index difference, the index difference being the difference between the index of the OFDM symbol occupied by the first demodulation reference signal and the index of the OFDM symbol occupied by the second demodulation reference signal, wherein the index of the OFDM symbol or the index difference is used to indicate the pattern of the second demodulation reference signal.

[0026] In one possible implementation, the first indication information includes: the location of the frequency resource corresponding to the second demodulation reference signal, wherein: if the frequency resource corresponding to the second demodulation reference signal is sparsely mapped onto the scheduling bandwidth, the location includes: the starting frequency resource location and the sparse density; or, if the frequency resource corresponding to the second demodulation reference signal occupies at least one resource block on the scheduling bandwidth, the location includes: at least two of the following: the starting position, the ending position, and the size of each resource block in the at least one resource block.

[0027] In one possible implementation, if the first signal waveform is a single-carrier waveform, the frequency resources corresponding to the second demodulation reference signal are sparsely mapped onto the scheduling bandwidth; or, if the first signal waveform is a multi-carrier waveform, the frequency resources corresponding to the second demodulation reference signal occupy at least one resource block on the scheduling bandwidth, or the frequency resources corresponding to the second demodulation reference signal are sparsely mapped onto the scheduling bandwidth.

[0028] In one possible implementation, the at least one resource block corresponds one-to-one with at least one precoded subband that is precoded.

[0029] In one possible implementation, the first demodulation reference signal includes: a pre-demodulation reference signal, or a pre-demodulation reference signal and an additional demodulation reference signal.

[0030] In one possible implementation, the first demodulation reference signal and the second demodulation reference signal are time-division multiplexed.

[0031] In one possible implementation, the non-demodulation reference signal carrier position on the OFDM symbol where the second demodulation reference signal is located is used to transmit user data.

[0032] In one possible implementation, the second communication device may further send second indication information to the third communication device. This second indication information indicates a third demodulation reference signal and a fourth demodulation reference signal, where the fourth demodulation reference signal is a zero-power demodulation reference signal with zero power. The port number used to send the third demodulation reference signal is the same as the port number used to send the first demodulation reference signal. Further, the device receives a second PUSCH sent by the third communication device based on the second indication information. This second PUSCH carries the third and fourth demodulation reference signals, which are used for channel estimation. The third communication device is also a terminal or a component (or device) within a terminal. The first and third communication devices correspond to different terminal devices. To accurately estimate the channel between the network device and each terminal device, the second demodulation reference signal indicated by the second communication device to the first communication device and the fourth demodulation reference signal indicated by the second communication device to the third communication device require different resources. As an example, the fourth demodulation reference signal and the second demodulation reference signal are time-division multiplexed, and / or the fourth demodulation reference signal and the second demodulation reference signal occupy different resource blocks in terms of frequency.

[0033] Thirdly, this application provides a communication device applied to the first communication device described in the first aspect above. The device includes: a receiving unit configured to receive first indication information, the first indication information indicating a first demodulation reference signal and a second demodulation reference signal, the second demodulation reference signal being a zero-power demodulation reference signal with zero power; and a transmitting unit configured to transmit a first physical uplink shared channel (PUSCH) according to the first indication information, the first PUSCH carrying the first demodulation reference signal and the second demodulation reference signal, the first demodulation reference signal and the second demodulation reference signal being used for channel estimation.

[0034] In one possible implementation, the first indication information includes: a first signal waveform corresponding to the first PUSCH and / or a first sequence corresponding to the first demodulation reference signal, the first signal waveform and / or the first sequence being used to determine the pattern of the second demodulation reference signal; the apparatus further includes: a processing unit, used to determine the pattern of the second demodulation reference signal based on the first signal waveform and / or the first sequence before transmitting the first PUSCH.

[0035] In one possible implementation, the processing unit is configured to: determine the pattern of the second demodulation reference signal based on the first signal waveform and a first correspondence between the signal waveform and the pattern, wherein the first correspondence includes at least the correspondence between the first signal waveform and the pattern of the second demodulation reference signal; or, determine the pattern of the second demodulation reference signal based on the first sequence and a second correspondence between the sequence and the pattern, wherein the second correspondence includes at least the correspondence between the first sequence and the pattern of the second demodulation reference signal; or, determine the pattern of the second demodulation reference signal based on the first signal waveform, the first sequence, and a third correspondence between the signal waveform, the sequence, and the pattern, wherein the third correspondence includes at least the correspondence between the first signal waveform, the first sequence, and the pattern of the second demodulation reference signal.

[0036] In one possible implementation, the first indication information includes: a pattern index of the second demodulation reference signal, the pattern index of the second demodulation reference signal being used to determine the pattern of the second demodulation reference signal.

[0037] In one possible implementation, the first indication information includes: an index of the orthogonal frequency division multiplexing (OFDM) symbol occupied by the second demodulation reference signal; or, an index difference, wherein the index difference is the difference between the index of the OFDM symbol occupied by the first demodulation reference signal and the index of the OFDM symbol occupied by the second demodulation reference signal, and the index of the OFDM symbol or the index difference is used to indicate the pattern of the second demodulation reference signal.

[0038] In one possible implementation, the first indication information includes: the location of the frequency resource corresponding to the second demodulation reference signal, wherein: if the frequency resource corresponding to the second demodulation reference signal is sparsely mapped onto the scheduling bandwidth, the location includes: the starting frequency resource location and the sparse density; or, if the frequency resource corresponding to the second demodulation reference signal occupies at least one resource block on the scheduling bandwidth, the location includes: at least two of the following: the starting position, the ending position, and the resource block size of each resource block in the at least one resource block.

[0039] In one possible implementation, if the first signal waveform is a single-carrier waveform, the frequency resources corresponding to the second demodulation reference signal are sparsely mapped onto the scheduling bandwidth; or, if the first signal waveform is a multi-carrier waveform, the frequency resources corresponding to the second demodulation reference signal occupy at least one resource block on the scheduling bandwidth, or the frequency resources corresponding to the second demodulation reference signal are sparsely mapped onto the scheduling bandwidth.

[0040] In one possible implementation, the at least one resource block corresponds one-to-one with at least one precoded subband that is precoded.

[0041] In one possible implementation, the first demodulation reference signal includes: a pre-demodulation reference signal, or a pre-demodulation reference signal and an additional demodulation reference signal.

[0042] In one possible implementation, the first demodulation reference signal and the second demodulation reference signal are time-division multiplexed.

[0043] In one possible implementation, the non-demodulation reference signal carrier position on the OFDM symbol where the second demodulation reference signal is located is used to transmit user data.

[0044] Fourthly, embodiments of this application provide a communication device applied to the second communication device described in the second aspect above. The device includes: a transmitting unit, configured to transmit first indication information, the first indication information being used to indicate a first demodulation reference signal and a second demodulation reference signal, the second demodulation reference signal being a zero-power demodulation reference signal with zero power; and a receiving unit, configured to receive a first physical uplink shared channel (PUSCH) transmitted based on the first indication information, the first PUSCH carrying the first demodulation reference signal and the second demodulation reference signal, the first demodulation reference signal and the second demodulation reference signal being used for channel estimation.

[0045] In one possible implementation, the first indication information includes: a first signal waveform corresponding to the first PUSCH and / or a first sequence corresponding to the first demodulation reference signal, wherein the first signal waveform and / or the first sequence are used to determine the pattern of the second demodulation reference signal.

[0046] In one possible implementation, the first indication information includes: a pattern index of the second demodulation reference signal, the pattern index of the second demodulation reference signal being used to determine the pattern of the second demodulation reference signal.

[0047] In one possible implementation, the first indication information includes: an index of the orthogonal frequency division multiplexing (OFDM) symbol occupied by the second demodulation reference signal; or, an index difference, the index difference being the difference between the index of the OFDM symbol occupied by the first demodulation reference signal and the index of the OFDM symbol occupied by the second demodulation reference signal, wherein the index of the OFDM symbol or the index difference is used to indicate the pattern of the second demodulation reference signal.

[0048] In one possible implementation, the first indication information includes: the location of the frequency resource corresponding to the second demodulation reference signal, wherein: if the frequency resource corresponding to the second demodulation reference signal is sparsely mapped onto the scheduling bandwidth, the location includes: the starting frequency resource location and the sparse density; or, if the frequency resource corresponding to the second demodulation reference signal occupies at least one resource block on the scheduling bandwidth, the location includes: at least two of the following: the starting position, the ending position, and the size of each resource block in the at least one resource block.

[0049] In one possible implementation, if the first signal waveform is a single-carrier waveform, the frequency resources corresponding to the second demodulation reference signal are sparsely mapped onto the scheduling bandwidth; or, if the first signal waveform is a multi-carrier waveform, the frequency resources corresponding to the second demodulation reference signal occupy at least one resource block on the scheduling bandwidth, or the frequency resources corresponding to the second demodulation reference signal are sparsely mapped onto the scheduling bandwidth.

[0050] In one possible implementation, the at least one resource block corresponds one-to-one with at least one precoded subband that is precoded.

[0051] In one possible implementation, the first demodulation reference signal includes: a pre-demodulation reference signal, or a pre-demodulation reference signal and an additional demodulation reference signal.

[0052] In one possible implementation, the first demodulation reference signal and the second demodulation reference signal are time-division multiplexed.

[0053] In one possible implementation, the non-demodulation reference signal carrier position on the OFDM symbol where the second demodulation reference signal is located is used to transmit user data.

[0054] In one possible implementation, the transmitting unit is further configured to: transmit second indication information, the second indication information being used to indicate a third demodulation reference signal and a fourth demodulation reference signal, the fourth demodulation reference signal being a zero-power demodulation reference signal with zero power, wherein: the port number used to transmit the third demodulation reference signal is the same as the port number used to transmit the first demodulation reference signal; the receiving unit is further configured to receive a second PUSCH transmitted based on the second indication information, the second PUSCH carrying the third demodulation reference signal and the fourth demodulation reference signal, the third demodulation reference signal and the fourth demodulation reference signal being used for channel estimation; wherein: the fourth demodulation reference signal and the second demodulation reference signal are time-division multiplexed, and / or, the fourth demodulation reference signal and the second demodulation reference signal occupy different resource blocks in terms of frequency.

[0055] Fifthly, this application provides a communication device including at least one processor coupled to a memory.

[0056] In one example, the processor is configured to execute the method that implements the first aspect or any possible implementation of the first aspect. For example, the memory is configured to store a program or instructions; the at least one processor is configured to execute the program or instructions to cause the apparatus to implement the method that implements the first aspect or any possible implementation of the first aspect.

[0057] In yet another example, the processor is configured to execute the method that implements the second aspect or any possible implementation thereof. For example, the memory is configured to store a program or instructions; the at least one processor is configured to execute the program or instructions to cause the apparatus to implement the method that implements the second aspect or any possible implementation thereof.

[0058] Sixthly, this application provides a communication device including at least one logic circuit and an input / output interface.

[0059] In one example, the logic circuit is used to perform the method described in the first aspect and any of its possible implementations as described above.

[0060] In yet another example, the logic circuit is used to perform the method described in the second aspect described above and any of its possible implementations.

[0061] In a seventh aspect, this application provides a computer-readable storage medium for storing one or more computer-executable instructions, which, when executed by a processor, perform the method as described in any of the possible implementations of any of the first to second aspects described above.

[0062] Eighthly, this application provides a computer program product (or computer program) that, when executed by a processor, performs a method of any possible implementation of any one of the first to second aspects described above.

[0063] Ninthly, this application provides a chip system including at least one processor for supporting a communication device in implementing the functions involved in any possible implementation of any of the first to second aspects described above.

[0064] In one possible design, the chip system may further include a memory for storing program instructions and data necessary for the communication device. The chip system may be composed of chips or may include chips and other discrete devices. Optionally, the chip system may also include interface circuitry that provides program instructions and / or data to the at least one processor.

[0065] In a tenth aspect, this application provides a communication system comprising: a first device for performing the method described in the first aspect and any one of the first aspects above, and a second device for performing the method described in the second aspect and any one of the second aspects above.

[0066] The technical effects of any of the design methods in aspects three through ten can be found in the first and second aspects and their different design methods mentioned above, and will not be repeated here. Attached Figure Description

[0067] Figure 1a is a schematic diagram of an exemplary application scenario provided by an embodiment of this application;

[0068] Figure 1b is a schematic diagram of the architecture of the communication system 1000 used in the embodiments of this application;

[0069] Figure 2a is a schematic diagram of a type 1 DMRS provided in an embodiment of this application;

[0070] Figure 2b is a schematic diagram of a type 2 DMRS provided in an embodiment of this application;

[0071] Figure 2c is a schematic diagram of a downlink MU-MIMO scenario provided in an embodiment of this application;

[0072] Figure 2d is a schematic diagram of an uplink MU-MIMO scenario provided in an embodiment of this application;

[0073] Figure 2e is a schematic diagram of a port corresponding to DMRS provided in an embodiment of this application;

[0074] Figure 2f is a schematic diagram of the layout of an orthogonal port supported by DMRS provided in an embodiment of this application;

[0075] Figure 3 is a flowchart illustrating a communication method provided in an embodiment of this application;

[0076] Figure 4a is a schematic diagram of a pattern of a first demodulation reference signal and a second demodulation reference signal provided in an embodiment of this application;

[0077] Figure 4b is a schematic diagram of another pattern of a first demodulation reference signal and a second demodulation reference signal provided in an embodiment of this application;

[0078] Figure 4c is a schematic diagram of the zero-power demodulation reference signal provided in an embodiment of this application;

[0079] Figure 5 is a schematic diagram of the structure of a communication device provided in an embodiment of this application;

[0080] Figure 6 is a schematic diagram of another communication device provided in an embodiment of this application;

[0081] Figure 7 is a schematic diagram of another communication device provided in an embodiment of this application;

[0082] Figure 8 is a schematic diagram of another communication device provided in an embodiment of this application. Detailed Implementation

[0083] This application provides a communication method that can improve the accuracy of channel estimation.

[0084] Before introducing the solutions provided in the embodiments of this application, the application scenarios of the embodiments of this application will be introduced first.

[0085] Referring to Figure 1a, which is a schematic diagram of an exemplary application scenario provided by an embodiment of this application, the scenario shown in Figure 1a includes a network device and a terminal device. It should be noted that although the scenario shown in Figure 1a involves communication between a network device and a terminal device, the solution of this application can also be applied to scenarios where terminal devices communicate with each other. That is, the network device shown in Figure 1a can also be replaced by a terminal device. In the following examples of this application, communication between a network device and a terminal device will be used as an example for illustration.

[0086] As shown in Figure 1a, the terminal device can send a PUSCH to the network device, and the network device performs channel estimation based on the DMRS grown in the PUSCH.

[0087] In this embodiment, the network device is a device deployed in a radio access network (RAN) to provide wireless communication functions for terminal devices. The network device may include various forms of macro base stations, micro base stations (also called small stations), relay stations, access points, etc. The name of the network device may differ in scenarios employing different wireless access technologies, for example:

[0088] In a Global System for Mobile Communication (GSM) or Code Division Multiple Access (CDMA) network, network equipment can be a base transceiver station (BTS).

[0089] In a wideband code division multiple access (WCDMA) network, network equipment can be a base station (BS) in a node.

[0090] In a long term evolution (LTE) network, network equipment can be an evolved NodeB (eNodeB).

[0091] In a cloud radio access network (CRAN), the network device can be a wireless controller.

[0092] Network equipment can also be base station equipment in 5G networks or future communication systems, or network equipment in future evolved public land mobile networks (PLMNs). Network equipment can also be wearable devices or vehicle-mounted devices. Network equipment can also be a transmission and reception point (TRP).

[0093] In some scenarios, "network device" can be understood as a collective term for all devices (including sites) on the network side; for example, multiple sites can be collectively referred to as network devices. A site refers to a transmission node located at a specific physical location. In other words, network devices can include sites.

[0094] In this application embodiment, the terminal device involved may include various handheld devices, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem with wireless communication capabilities. The terminal may be a mobile station (MS), subscriber unit, cellular phone, smartphone, wireless data card, personal digital assistant (PDA) computer, tablet computer, wireless modem, handset, laptop computer, machine type communication (MTC) terminal, etc.

[0095] The aforementioned wireless access network can be understood with reference to the communication system shown in Figure 1a. Figure 1b is a schematic diagram of the architecture of the communication system 1000 used in the embodiments of this application. As shown in Figure 1b, the communication system 1000 includes a RAN 100 and a core network 200. Optionally, the communication system 1000 may also include an Internet 300. The RAN 100 includes at least one RAN node (as shown in Figure 1b, 110a and 110b, collectively referred to as 110; the aforementioned network devices can correspond to RAN nodes), and may also include at least one terminal (as shown in Figure 1b, 120a-120j, collectively referred to as 120). The RAN 100 may also include other RAN nodes, such as wireless relay devices and / or wireless backhaul devices (not shown in Figure 1b). The terminal 120 is wirelessly connected to the RAN node 110, and the RAN node 110 is wirelessly or wiredly connected to the core network 200. The core network equipment in core network 200 and the RAN node 110 in RAN 100 can be independent physical devices, or they can be the same physical device that integrates the logical functions of the core network equipment and the logical functions of the RAN node. Terminals can be interconnected with each other, and RAN nodes can be interconnected with each other, via wired or wireless means.

[0096] RAN100 can be an evolved universal terrestrial radio access (E-UTRA) system, a new radio (NR) system, or a future radio access system as defined in the 3rd generation partnership project (3GPP). RAN100 can also include two or more of the above-mentioned different radio access systems. RAN100 can also be an open RAN (O-RAN).

[0097] RAN nodes, also known as radio access network devices, RAN entities, or access nodes, are used to help terminals access communication systems wirelessly. In one application scenario, an RAN node can be a base station, an evolved RAN base station, a transmission reception point (TRP), a next-generation NodeB (gNB) in a 5G mobile communication system, a next-generation base station in a 6G mobile communication system, or a base station in a future mobile communication system. RAN nodes can be macro base stations (such as 110a in Figure 1b), micro base stations or indoor stations (such as 110b in Figure 1b), relay nodes, or donor nodes.

[0098] In another application scenario, multiple RAN nodes can collaborate to help terminals achieve wireless access, with different RAN nodes implementing different functions of the base station. For example, a RAN node can be a central unit (CU), a distributed unit (DU), or a radio unit (RU). Here, the CU performs the functions of the base station's Radio Resource Control (RRC) and Packet Data Convergence Protocol (PDCP), and can also perform the functions of the Service Data Adaptation Protocol (SDAP). The DU performs the functions of the base station's Radio Link Control (RANC) and Medium Access Control (MAC) layers, and can also perform some or all of the physical layer functions. For specific descriptions of these protocol layers, refer to the relevant 3GPP technical specifications. The RU can be used to implement radio frequency signal transmission and reception. The CU and DU can be two independent RAN nodes or integrated into the same RAN node, such as within a baseband unit (BBU). The RU can be included in radio frequency equipment, such as in a remote radio unit (RRU) or an active antenna unit (AAU). The CU can be further divided into two types of RAN nodes: CU-control plane and CU-user plane.

[0099] In different systems, RAN nodes may have different names. For example, in an open access network (open RAN, O-RAN, or ORAN) system, a CU can also be called an O-CU (open CU), a DU can also be called an O-DU, a CU-CP can also be called an O-CU-CP, a CU-UP can also be called an O-CU-UP, and a RU can also be called an O-RU. For ease of description, this application uses CU, CU-CP, CU-UP, DU, and RU as examples. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software modules and hardware modules.

[0100] Communication between access network devices and terminal devices follows a specific protocol layer structure. This protocol layer may include a control plane protocol layer and a user plane protocol layer. The control plane protocol layer may include at least one of the following: radio resource control (RRC) layer, packet data convergence protocol (PDCP) layer, radio link control (RLC) layer, media access control (MAC) layer, or physical (PHY) layer, etc. The user plane protocol layer may include at least one of the following: service data adaptation protocol (SDAP) layer, PDCP layer, RLC layer, MAC layer, or physical layer, etc.

[0101] The correspondence between network elements and their achievable protocol layer functions in the ORAN system can be found in Table 1 below.

[0102] Table 1

[0103] For ease of description, the following text uses a base station as an example of a RAN node.

[0104] A terminal is a device with wireless transceiver capabilities, capable of sending signals to or receiving signals from a base station. Terminals can also be called terminal equipment, user equipment (UE), mobile station, mobile terminal, etc. Terminals can be widely used in various scenarios, such as device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IoT), virtual reality, augmented reality, industrial control, autonomous driving, telemedicine, smart grids, smart furniture, smart offices, smart wearables, smart transportation, smart cities, etc. Terminals can be mobile phones, tablets, computers with wireless transceiver capabilities, wearable devices, vehicles, airplanes, ships, robots, robotic arms, smart home devices, etc. The embodiments of this application do not limit the specific technology or device form used in the terminal.

[0105] Base stations and terminals can be fixed or mobile. They can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on water; and they can be deployed on aircraft, balloons, and satellites. The embodiments of this application do not limit the application scenarios of the base stations and terminals.

[0106] The roles of base stations and terminals can be relative. For example, the helicopter or drone 120i in Figure 1 can be configured as a mobile base station. For terminals 120j that access the wireless access network 100 through 120i, terminal 120i is a base station; however, for base station 110a, 120i is a terminal, meaning that 110a and 120i communicate via a wireless air interface protocol. Of course, 110a and 120i can also communicate via a base station-to-base station interface protocol. In this case, relative to 110a, 120i is also a base station. Therefore, both base stations and terminals can be collectively referred to as communication devices. 110a and 110b in Figure 1 can be called communication devices with base station functions, and 120a-120j in Figure 1 can be called communication devices with terminal functions.

[0107] Communication between base stations and terminals, between base stations, and between terminals can be conducted using licensed spectrum, unlicensed spectrum, or both simultaneously. Communication can be conducted using spectrum below 6 GHz, spectrum above 6 GHz, or both simultaneously. The embodiments of this application do not limit the spectrum resources used for wireless communication.

[0108] In the embodiments of this application, the functions of the base station can be executed by modules (such as chips) within the base station, or by a control subsystem that includes base station functions. This control subsystem, including base station functions, can be a control center in the aforementioned application scenarios such as smart grids, industrial control, intelligent transportation, and smart cities. Similarly, the functions of the terminal can be executed by modules (such as chips or modems) within the terminal, or by a device that includes terminal functions.

[0109] In wireless communication systems (such as the communication system 1000 shown in Figure 1b), MIMO technology, as a key technology in wireless communication, can be used to meet the demand for high-speed transmission. Taking the communication process between network devices and terminal devices as an example, the terminal device can send DMRS to the network device, and the network device can use the DMRS to perform channel estimation to facilitate subsequent communication with the terminal device.

[0110] The demodulation reference signal is mainly used for channel estimation. DMRS includes: DMRS based on the physical downlink shared channel (PDSCH), DMRS based on the physical downlink control channel (PDCCH), DMRS based on the physical uplink shared channel (PUSCH), and DMRS based on the physical uplink control channel (PUCCH).

[0111] Taking DMRS for PDSCH as an example, DMRS includes two types: type 1 and type 2.

[0112] As shown in Figure 2a, Figure 2a is a schematic diagram of a type 1 DMRS provided in an embodiment of this application. In Figure 2a, each small square represents a resource, where the horizontal axis represents time-domain resources and the vertical axis represents frequency-domain resources. Each small square corresponds to one OFDM symbol in the time domain and one frequency-domain resource element (RE) in the frequency domain.

[0113] The DMRS shown on the left in Figure 2a occupies a single orthogonal frequency division multiplexing (OFDM) symbol in the time domain, while the DMRS shown on the right in Figure 2a occupies two OFDM symbols in the time domain.

[0114] Type 1 DMRS has a frequency domain density of 1 / 2. For the DMRS pattern on the left side of Figure 2a, the corresponding antenna port numbers are 1000–1003; for the DMRS pattern on the right side of Figure 2a, the corresponding antenna port numbers are 1000–1007. The shaded squares in Figure 2a are used to distinguish different code division multiplexing (CDM) groups. One shade corresponds to one CDM group. Within the same CDM group, different antenna ports are distinguished by orthogonal cover codes (OCC). For example, for antenna port numbers 1001 and 1001 shown in Figure 2a, the receiver (e.g., network equipment) uses two frequency domain orthogonal cover codes (OCC) of [+1, +1] and [+1, -1] respectively to distinguish the different ports. Similarly, for antenna port numbers 1000, 1001, 1004, and 1005 shown in Figure 2a, the receiver uses four frequency domain OCC codes [+1, +1, +1, +1], [+1, +1, -1, -1], [+1, -1, +1, -1], and [+1, -1, -1, +1] to distinguish different ports, respectively. For ports belonging to different CDM groups, they can be directly distinguished using frequency domain resources and / or time domain resources.

[0115] Referring to Figure 2b, Figure 2b is a schematic diagram of a type 2 DMRS provided in an embodiment of this application.

[0116] The DMRS shown on the left in Figure 2b occupies a single OFDM symbol in the time domain, while the DMRS shown on the right in Figure 2b occupies two OFDM symbols in the time domain.

[0117] The frequency density of type 2 DMRS is 1 / 3. For the DMRS pattern on the left side of Figure 2b, the corresponding antenna port numbers are 1000–1005; for the DMRS pattern on the right side of Figure 2b, the corresponding antenna port numbers are 1000–1011. Type 2 DMRS corresponds to 3 CDM groups. Similar to type 1 DMRS, within the same CDM group, different antenna ports are distinguished by OCC codes. For ports belonging to different CDM groups, they can be directly distinguished by frequency domain resources and / or time domain resources.

[0118] In one example, DMRS for PUSCH can include front-loaded (FL) DMRS and additional DMRS. In other words, PUSCH can carry both front-loaded and additional DMRS. The front-loaded DMRS can be used for channel estimation. In some scenarios, if channel estimation using front-loaded DMRS is ineffective, both front-loaded and additional DMRS can be combined to improve the channel estimation performance.

[0119] The port mentioned above refers to the antenna port. An antenna port can be understood as a transmitting antenna that is identified by the receiving end, or a spatially distinguishable transmitting antenna. An antenna port can be pre-configured for each virtual antenna. Each virtual antenna can be a weighted combination of multiple physical antennas, and each antenna port can correspond to a reference signal (RS). Therefore, each antenna port can be called a port of a reference signal. For example, each antenna port can be called a DMRS port.

[0120] In this context, an antenna port is a logical concept, and there is generally no direct correspondence between an antenna port and a physical antenna. An antenna port is typically associated with a reference signal, and its meaning can be understood as a transmit / receive interface on the channel through which the reference signal passes. For low frequencies, an antenna port may correspond to one or more antenna elements that jointly transmit the reference signal; the receiver can treat them as a whole without distinguishing between individual elements. For high-frequency systems, an antenna port may correspond to a beam; similarly, the receiver needs to treat this beam as an interface without distinguishing between individual elements.

[0121] Referring to Figure 2c, this figure is a schematic diagram of a downlink MU-MIMO scenario provided by an embodiment of this application.

[0122] In the scenario shown in Figure 2c, the network device is the BS and the terminal device is the UE. The BS estimates the downlink channel using the sounding reference signal (SRS) sent by the UE and the reciprocity of the uplink and downlink channels. It then performs transmit-end precoding to eliminate inter-user interference. However, due to non-ideal SRS factors (e.g., interference, path loss) and the precoding granularity, residual interference still exists between signals sent to multiple UEs. Nevertheless, since precoding has eliminated the main energy interference, the orthogonality requirement for the DMRS ports is relatively low. The precoding granularity can be used to indicate the range of frequency resources covered by the precoding. See the description below for details.

[0123] Regarding precoding techniques, it should be noted that:

[0124] The transmitting end can process the signal to be transmitted using a precoding matrix that matches the channel, given the known channel conditions, thus ensuring the precoded signal is compatible with the channel. Therefore, compared to the receiving end receiving an un-precoded signal and eliminating inter-channel interference, the complexity of receiving a precoded signal and eliminating inter-channel interference is reduced. Consequently, by precoding the signal to be transmitted, the quality of the received signal (e.g., signal-to-interference-plus-noise ratio, SINR) is improved. Precoding technology also enables the transmitting end and multiple receiving ends to transmit on the same time-frequency resources, achieving MU-MIMO. The transmitting end can perform precoding at a specific granularity, with the unit being a resource element group (REG). Depending on the granularity, precoding can include sub-band precoding and full-band precoding. Subband precoding refers to precoding at a precoding granularity x, where x is less than the number of resource blocks (RBs) included in the scheduling bandwidth. One RB and one REG each contain 12 REs. Full-band precoding, on the other hand, performs precoding once according to the number of RBs included in the scheduling bandwidth.

[0125] Optionally, the sending end can be a network device and the receiving end can be a terminal device; or, the sending end can be a terminal device and the receiving end can be a terminal device.

[0126] One implementation employs Multiple Input Multiple Output (MIMO) technology to increase system capacity and improve throughput. The mathematical expression is y = Hx + n, where y is the received signal, H is the channel matrix of the MIMO channel, x is the transmitted signal, and n is noise. In communication systems with multiple antennas, signals from multiple transmit antennas can be superimposed on any one receive antenna. Therefore, the method of transmitting signals at the transmitter affects system performance, and recovering the transmitted signal at the receiver is often complex. In this context, precoding is used to reduce system overhead and maximize the system capacity of MIMO, while also reducing the complexity of eliminating inter-channel interference at the receiver. In this case, the mathematical expression is y = HPx + n, where P is the precoding matrix (or vector). To simplify implementation complexity, P can be selected from a predefined set of matrices (or vectors), called the codebook. This method is also known as a codebook-based transmission method. If the sending end can obtain all the information of H, then P can be obtained by the sending end itself. This method is also known as the non-codebook (NCB) sending method.

[0127] It should be understood that the descriptions of precoding techniques are for illustrative purposes only and are not intended to limit the scope of protection of the embodiments of this application. In specific implementations, the transmitting end may also perform precoding in other ways. For example, when channel information (e.g., but not limited to the channel matrix) is unknown, a pre-set precoding matrix or a weighted processing method may be used for precoding. For the sake of brevity, the specific details will not be elaborated upon here.

[0128] See Figure 2d, which is a schematic diagram of an uplink MU-MIMO scenario provided by an embodiment of this application.

[0129] In the scenario shown in Figure 2d, the network device is again the BS (Browser / Server) and the terminal device is the UE (User Equipment). As shown in Figure 2d, since interference suppression cannot be performed between UEs, it relies entirely on the receiving end, i.e., the BS, for processing. That is, when multiple UEs send DMRS to the BS, the DMRS sent by multiple UEs will interfere with each other. To eliminate this interference, the ports used by each UE to send DMRS can be controlled to maintain good orthogonality. In other words, the BS can use orthogonal ports to eliminate interference from other UEs.

[0130] As the number of users (i.e., the number of UEs) increases, for example, in the upper 6G (U6G) frequency band, the number of UEs can reach 64. The port design can then be referenced in Figure 2e, which is a schematic diagram of a port corresponding to a DMRS provided in an embodiment of this application. In Figure 2e, the shaded squares correspond to resources used to carry the DMRS, while the unshaded squares are used to carry user data. As shown in Figure 2e, as the number of ports increases, the resources occupied by the DMRS also increase, and correspondingly, the resources used to carry user data decrease, resulting in lower PUSCH resource utilization. In Figure 2e, the time domain orthogonal cover code (TD-OCC) refers to the number of OFDM symbols occupied by the DMRS in the time domain, and the circular shift (CS) refers to the number of frequency domain CDM ports.

[0131] In addition, when sending PUSCH to network devices, terminal devices can send different signals. For example, they can send cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) signals, or discrete fourier transformation spreading OFDM (DFT-s-OFDM) signals.

[0132] When a terminal device sends a PUSCH carrying a CP-OFDM signal to a network device, the DMRS carried by the PUSCH is generated from a gold sequence. When a terminal device sends a PUSCH carrying a DFT-s-OFDM signal to a network device, the DMRS carried by the PUSCH is generated from a Zadoff-Chu (ZC) sequence, or from a gold sequence mapped to a pi / 2 binary phase shift keying (BPSK) sequence. Because different sequences are generated using different orthogonal basis functions, frequency-domain CDM and / or time-domain CDM cannot be performed between CP-OFDM signals and DFT-s-OFDM signals.

[0133] In one example, orthogonal ports are required between different terminal devices transmitting a certain signal (e.g., CP-OFDM or DFT-s-OFDM). This can be understood in conjunction with Figure 2f, which is a schematic diagram of the layout of orthogonal ports supported by DMRS according to an embodiment of this application.

[0134] As shown in Figure 2f, DMRS supports 8 quadrature ports for CP-OFDM signals and 8 quadrature ports for DFT-s-OFDM signals. In the left-hand section of Figure 2f, the solid-lined area in the attached diagram "(a) Equalization Combination" represents 8 terminal devices. These 8 terminal devices can use the aforementioned 8 quadrature ports supporting CP-OFDM signals to send DMRS to the network device. The dashed-lined area in the left-hand attached diagram (a) of Figure 2f also represents 8 terminal devices. These 8 terminal devices can use the aforementioned 8 quadrature ports supporting DFT-s-OFDM to send DMRS to the network device.

[0135] In this scenario, when the number of terminal devices transmitting CP-OFDM signals is the same as the number of terminal devices transmitting DFT-s-OFDM signals, for example, both reaching 8, the multiplexing capability of the aforementioned 16 ports is maximized (corresponding to the situation shown in Figure 2f, left side appendix (a)). When the number of terminal devices transmitting CP-OFDM signals is different from the number of terminal devices transmitting DFT-s-OFDM signals, the multiplexing capability of the aforementioned 16 ports is poor. For example, when the number of terminal devices transmitting CP-OFDM signals is 12 and the number of terminal devices transmitting DFT-s-OFDM signals is 4 (corresponding to the situation shown in Figure 2f, right side appendix "(b) Uneven Combination"), although there are still 4 orthogonal ports available for transmitting DFT-s-OFDM signals that are idle, these 4 idle ports are not suitable for transmitting CP-OFDM signals. This is because if these 4 idle ports are used to transmit CP-OFDM signals, the transmitted CP-OFDM signals will be interfered with by signals transmitted by other terminal devices, thus preventing the network devices from accurately performing channel estimation.

[0136] In view of this, embodiments of this application provide a communication method that enables accurate channel estimation even without the need for the terminal device to transmit DMRS using orthogonal ports. Because the terminal device does not need to use orthogonal ports to transmit DMRS, the resource utilization of the PUSCH can be guaranteed even with an increasing number of users (meaning more PUSCH resources can be used to transmit user data).

[0137] Next, referring to Figure 3, taking the communication between network devices and terminal devices as an example, we will introduce the communication method provided in the embodiments of this application.

[0138] Figure 3 is a flowchart illustrating a communication method provided in an embodiment of this application. The method shown in Figure 3 includes the following steps S101-S104.

[0139] S101: The network device sends a first indication information to the first terminal device. The first indication information is used to indicate a first demodulation reference signal and a second demodulation reference signal. The second demodulation reference signal is a zero-power demodulation reference signal with zero power.

[0140] In one example, the first demodulation reference signal may be a pre-demodulation reference signal. In this scenario, the first indication information can be used to indicate both the pre-demodulation reference signal and a zero-power demodulation reference signal with zero power. The zero-power demodulation reference signal with zero power can also be understood as a demodulation reference signal with an amplitude of zero.

[0141] In yet another example, the first demodulation reference signal may include a pre-demodulation reference signal and an additional demodulation reference signal. In this scenario, the first indication information can be used to indicate the pre-demodulation reference signal, the additional demodulation reference signal, and a zero-power demodulation reference signal with zero power.

[0142] In this embodiment, the first indication information indicates the second demodulation reference signal, and may be a pattern indicating the second demodulation reference signal. This embodiment does not specifically limit the manner in which the first indication information indicates the pattern of the second demodulation reference signal; several possible methods are described below.

[0143] As a specific example, the pattern of the second demodulation reference signal can be related to the first signal waveform corresponding to the first PUSCH. Therefore, in one example, the first indication information may include the first signal waveform, which indicates the pattern of the second demodulation reference signal. The first indication information includes the first signal waveform; for example, it may include an identifier of the first signal waveform. This application does not specifically limit the first signal waveform; the first signal waveform may be one of CP-OFDM, DFT-s-OFDM, and filter subcarrier quadrature amplitude modulation (Filter SC-QAM).

[0144] As another concrete example, the pattern of the second demodulated reference signal can be associated with a first sequence corresponding to the first demodulated reference signal (e.g., a pre-demodulation reference signal). Therefore, in one example, the first indication information may include the first sequence, which indicates the pattern of the second demodulated reference signal. The first indication information includes the first sequence, for example, it may include an identifier of the first sequence. This application does not specifically limit the first sequence; the first sequence can be determined according to actual conditions. For example, the first sequence may be one of sequences such as ZC sequence, gold sequence, pi / 2BPSK sequence, and golay.

[0145] As another specific example, the pattern of the second demodulation reference signal may be related to both the aforementioned first signal waveform and the first sequence. In this case, the first indication information may include the first signal waveform and the first sequence, and the pattern of the second demodulation reference signal may be indicated by the first signal waveform and the first sequence.

[0146] As another concrete example, the pattern index of the second demodulated reference signal can be used to determine the pattern of the second demodulated reference signal. Therefore, in one example, the first indication information includes the pattern index of the second demodulated reference signal, which indicates the pattern of the second demodulated reference signal. The pattern index of the second demodulated reference signal may, for example, correspond to a number.

[0147] As another specific example, considering that the pattern of the second demodulated reference signal includes information on both the time-domain and frequency-domain resources it occupies, the first indication information can be used to indicate the time-domain resources occupied by the second demodulated reference signal and / or the frequency-domain resources occupied by the second demodulated reference signal.

[0148] In one example, the time-domain resources occupied by the second demodulation reference signal refer to the location of the OFDM symbol occupied by the second demodulation reference signal. As an example, the location of the OFDM symbol occupied by the second demodulation reference signal can be indicated by the index of the OFDM symbol occupied by the second demodulation reference signal. Therefore, the first indication information may include the index of the OFDM symbol occupied by the second demodulation reference signal, using this index to indicate the location of the OFDM symbol occupied by the second demodulation reference signal. As yet another example, the location of the OFDM symbol occupied by the second demodulation reference signal can be determined by the difference between the index of the OFDM symbol occupied by the first demodulation reference signal and the index of the OFDM symbol occupied by the second demodulation reference signal (referred to as the index difference). Therefore, the first indication information may include the index difference, using this index difference to indicate the location of the OFDM symbol occupied by the second demodulation reference signal.

[0149] In yet another example, the first indication information may include the location of the frequency domain resources corresponding to the second demodulation reference signal, so as to indicate the location of the frequency domain resources occupied by the second demodulation reference signal.

[0150] In one example, the frequency domain resources corresponding to the second demodulation reference signal can be sparsely mapped onto the scheduling bandwidth. This sparse mapping of frequency resources onto the scheduling bandwidth can be understood as uniform mapping of frequency resources onto the scheduling bandwidth. For example, when the aforementioned first signal waveform is a single-carrier waveform, such as a DFT-s-OFDM signal waveform, in order to maintain the low peak-to-average power ratio (PAPR) of the low-carrier waveform, the frequency domain resources corresponding to the second demodulation reference signal are preferably sparsely mapped onto the scheduling bandwidth. Of course, when the aforementioned first signal waveform is a dual-carrier waveform, such as a CP-OFDM signal waveform, the frequency domain resources corresponding to the second demodulation reference signal can be sparsely mapped onto the scheduling bandwidth.

[0151] In another example, the frequency domain resources corresponding to the second demodulation reference signal can also occupy at least one resource block on the scheduling bandwidth. For example, when the first signal waveform is a single-carrier waveform or a dual-carrier waveform, the frequency domain resources corresponding to the second demodulation reference signal can also occupy at least one resource block on the scheduling bandwidth.

[0152] In this embodiment, if the frequency resource corresponding to the second demodulation reference signal is sparsely mapped onto the scheduling bandwidth, the location of the frequency resource corresponding to the second demodulation reference signal can include the starting frequency resource location and sparse density of the frequency domain resource corresponding to the second demodulation reference signal. Based on the starting frequency resource location and sparse density, the location of the frequency domain resource corresponding to the second demodulation reference signal can be determined. The sparse density can be understood as the ratio of the frequency resource corresponding to the second demodulation reference signal to the frequency resources included in the entire scheduling bandwidth. For example, a sparse density of 0.5 indicates that the frequency resource corresponding to the second demodulation reference signal accounts for half of the frequency resources included in the entire scheduling bandwidth; that is, in the frequency resource corresponding to the second demodulation reference signal, any two adjacent frequency resources are separated by one frequency resource. Assuming the starting frequency resource location is 0 and the sparse density is 0.5, the location of the frequency domain resource corresponding to the second demodulation reference signal can be determined to include several frequency domain resources (e.g., resource elements) numbered 0, 2, 4…2n.

[0153] In this embodiment, if the frequency resource corresponding to the second demodulation reference signal occupies at least one resource block on the scheduling bandwidth, the location of the frequency resource corresponding to the second demodulation reference signal may include the location of the at least one resource block. That is, the location of the frequency domain resource corresponding to the second demodulation reference signal is indicated by indicating the location of the at least one resource block. For each resource block in the at least one resource block, the location of the resource block may include at least two of the following: the start position of the resource block, the end position of the resource block, and the resource block size. For example, for any resource block, the location of the resource block may be the start position and the resource block size. Alternatively, for any resource block, the location of the resource block may be the start position and the end position of the resource block. Yet another example is that for any resource block, the location of the resource block may be the resource block size and the end position. The resource block size may, for example, be the number of resource elements included in the resource block.

[0154] In one example, if the frequency resource corresponding to the aforementioned second demodulation reference signal occupies at least one resource block on the scheduling bandwidth, then in one example, the at least one resource block can correspond one-to-one with at least one precoding sub-band precoded by the network device. In this way, after the network device executes S104, when evaluating interference from other terminal devices based on the second demodulation reference, it can estimate the interference from other terminal devices on each precoding sub-band.

[0155] In this embodiment, the first demodulation reference signal and the second demodulation reference signal need to have a certain degree of isolation, so that the network device can assess interference from other terminal devices based on the second demodulation reference signal. In a specific example, the first demodulation reference signal and the second demodulation reference signal are time-division multiplexed, that is, the first demodulation reference signal and the second demodulation reference signal can occupy different OFDM symbols in the time domain. Specifically, the second demodulation reference signal can occupy one OFDM symbol or multiple OFDM symbols in the time domain; this embodiment does not impose a specific limitation.

[0156] In this embodiment, the second demodulation reference signal is a newly introduced demodulation reference signal. The resources (time domain resources and frequency domain resources) occupied by the second demodulation reference signal were originally used to carry user data. In this embodiment, the non-demodulation reference signal carrier positions on the OFDM symbol where the second demodulation reference signal is located are still used to transmit user data, thereby effectively utilizing the resources of the first PUSCH. Here, the OFDM symbol where the second demodulation reference signal is located refers to the OFDM symbol occupied by the second demodulation reference signal. In some scenarios, the OFDM symbol occupied by the second demodulation reference signal can also be described as the OFDM symbol corresponding to the second demodulation reference signal.

[0157] Regarding the patterns of the first demodulation reference signal and the second demodulation reference signal, the following explanation will be given with reference to Figures 4a and 4b, taking the first demodulation reference signal as an example. Figure 4a is a schematic diagram of the patterns of the first demodulation reference signal and the second demodulation reference signal provided in an embodiment of this application. Figure 4b is a schematic diagram of the patterns of the first demodulation reference signal and the second demodulation reference signal provided in another embodiment of this application.

[0158] As shown in Figure 4a, the pattern of the pre-demodulation reference signal corresponds to 401 in the figure. In the time domain, it occupies the 3rd and 4th OFDM symbols, and its frequency RBs are numbered 1, 3, 5, ... 2n+1. The pattern of the zero-power demodulation reference signal corresponds to 402 in the figure. In Figure 4a, the zero-power demodulation reference signal occupies the first OFDM symbol in the time domain, and it is time-division multiplexed with the pre-demodulation reference signal 401. The pattern of the zero-power demodulation reference signal is sparsely mapped on the scheduling bandwidth. Specifically, its frequency RBs are numbered 0, 2, 4, ... 2n.

[0159] As shown in Figure 4b, the pattern of the pre-demodulation reference signal corresponds to 403 in the figure. In the time domain, it occupies the 3rd and 4th OFDM symbols, and its frequency RBs are numbered 1, 3, 5, ..., 2m+1. The pattern of the zero-power demodulation reference signal corresponds to 404 in the figure. In Figure 4b, the zero-power demodulation reference signal occupies the first OFDM symbol in the time domain, and it is time-division multiplexed with the pre-demodulation reference signal 403. The pattern of the zero-power demodulation reference signal occupies one resource block on the scheduling bandwidth. The size of this resource block is two frequency domain resource elements.

[0160] In Figures 4a and 4b, the pre-demodulation reference signal and the zero-power demodulation reference signal occupy different OFDM symbols in the time domain. The pre-demodulation reference signal occupies two OFDM symbols in the time domain, while the zero-power demodulation reference signal occupies one OFDM symbol in the time domain.

[0161] In this embodiment of the application, the aforementioned first indication information may further include the time-domain resources of the first demodulation reference signal, the frequency-domain resources of the first demodulation reference signal, and the port number corresponding to the first demodulation reference signal. Wherein:

[0162] The time-domain resources of the first demodulation reference signal include at least one of the following parameters: system frame number, transmission timeslot, OFDM symbol start position, and number of time-domain OFDM symbols. In one example, the network device may indicate the time-domain resources of the first demodulation reference signal through the start and length indicator value (SLIV) field in the downlink control information (DCI).

[0163] The frequency domain resources of the aforementioned first demodulation reference signal include at least one parameter such as: the number of physical resource blocks (PRBs), bandwidth part (BWP), frequency band, serving cell ID, center frequency, and subcarrier spacing (SCS). In one example, the network device can indicate the frequency domain resources of the first demodulation reference signal via DCI or radio resource control (RRC) signaling.

[0164] The pattern of the demodulation reference signal carried by the PUSCH is similar to that carried by the PDSCH, and may also include type 1 and type 2. Therefore, the pattern of the first demodulation reference signal can be seen in Figures 2a and 2b, and it may also be type 1 or type 2.

[0165] If the pattern of the first demodulation reference signal corresponds to type 1 and it occupies a single OFDM symbol in the time domain, then the port number corresponding to the first demodulation reference signal can be one of 1000, 1001, 1002 and 1003.

[0166] If the pattern of the first demodulation reference signal corresponds to type 1 and it occupies two OFDM symbols in the time domain, then the port number corresponding to the first demodulation reference signal can be one of 1000, 1001, 1002, 1003, 1004, 1005, 1006 and 1007.

[0167] If the pattern of the first demodulation reference signal corresponds to type 2 and it occupies a single OFDM symbol in the time domain, then the port number corresponding to the first demodulation reference signal can be one of 1000, 1001, 1002, 1003, 1004, and 1005.

[0168] If the pattern of the first demodulation reference signal corresponds to type 2 and occupies two OFDM symbols in the time domain, then the port number corresponding to the first demodulation reference signal can be one of 1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007, 1008, 1009, 1010, and 1011. Wherein, if the aforementioned first signal waveform is a single-carrier waveform, then the pattern of the first demodulation reference signal preferably corresponds to type 1 to ensure the low PAPR characteristic of the single carrier.

[0169] It should be noted that, in this embodiment of the application, the network device can send the first indication information to the network device through one or more signaling messages. For example, the network device can carry all the information in the aforementioned first indication information through a single signaling message, or it can divide the aforementioned information into several parts, with each part carried through a different signaling message. This embodiment of the application does not impose any specific limitations.

[0170] S102: The first terminal device receives the first instruction information sent by the network device.

[0171] S103: The first terminal device sends a first PUSCH to the network device according to the first instruction information. The first PUSCH carries the first demodulation reference signal and the second demodulation reference signal.

[0172] After the network device sends the first instruction information to the first terminal device, the first terminal device can receive the first instruction information sent by the network device. After receiving the first instruction information, the first terminal device can determine the pattern of the first demodulation reference signal and the pattern of the second demodulation reference signal based on the first instruction information, and further generate the first demodulation reference signal and the second demodulation reference signal based on the patterns of the first demodulation reference signal and the second demodulation reference signal, so as to send the first PUSCH to the network device.

[0173] In one example, if the first indication information includes a first signal waveform used to indicate the pattern of a second demodulation reference signal, then the first terminal device can determine the pattern of the second demodulation reference signal based on a first correspondence between the signal waveform and the pattern, and the first signal waveform. The first correspondence mentioned herein can be a correspondence between an identifier of a signal waveform and a pattern identifier (e.g., a pattern index). The first correspondence can include multiple correspondences, at least including the correspondence between the first signal waveform and the pattern of the second demodulation reference signal.

[0174] This first correspondence can be understood in conjunction with Table 2 below. Each row in Table 2 represents a correspondence within the first correspondence.

[0175] Table 2

[0176] For example, if the first signal waveform included in the first indication information is CP-OFDM, then based on the correspondence shown in Table 2, the pattern of the second demodulation reference signal can be determined to be Pattern 1. As another example, if the first signal waveform included in the first indication information is DFT-s-OFDM, then based on the correspondence shown in Table 2, the pattern of the second demodulation reference signal can be determined to be Pattern 2. Furthermore, if the first signal waveform included in the first indication information is Filter SC-QAM, then based on the correspondence shown in Table 2, the pattern of the second demodulation reference signal can be determined to be Pattern 3.

[0177] In another example, if the first indication information includes a first sequence indicating the pattern of the second demodulation reference signal, the first terminal device can determine the pattern of the second demodulation reference signal based on a second correspondence between the sequence and the pattern and the first sequence. The second correspondence mentioned herein can be a correspondence between a sequence identifier and a pattern identifier (e.g., a pattern index). The second correspondence can include multiple correspondences, at least including the correspondence between the first sequence and the pattern of the second demodulation reference signal.

[0178] This second correspondence can be understood in conjunction with Table 3 below. Each row in Table 3 represents one of the correspondences in the second correspondence.

[0179] Table 3

[0180] For example, if the first sequence included in the first indication information is sequence 1, then based on the correspondence shown in Table 3, the pattern of the second demodulation reference signal can be determined to be pattern 1'. Similarly, if the first sequence included in the first indication information is sequence 2, then based on the correspondence shown in Table 3, the pattern of the second demodulation reference signal can be determined to be pattern 2'. And again, if the first sequence included in the first indication information is sequence 3, then based on the correspondence shown in Table 3, the pattern of the second demodulation reference signal can be determined to be pattern 3'.

[0181] Regarding Tables 2 and 3, it should be noted that:

[0182] For any pattern in Table 2 (e.g., pattern 1), it may be different from all the patterns shown in Table 3, or it may be the same as a certain pattern shown in Table 3 (e.g., pattern 1'). The embodiments of this application do not make specific limitations.

[0183] Regarding any two sequences from Sequence 1 to Sequence 3, these two sequences can be of the same type, such as a gold sequence, a ZC sequence, a golay sequence, or a pi / 2BPSK sequence, but with different specific sequence parameters. These two sequences can also be of different types; for example, one sequence may be a gold sequence and the other a ZC sequence, etc., which will not be listed here.

[0184] In another example, if the first indication information includes a first signal waveform and a first sequence, which are used to indicate the pattern of the second demodulation reference signal, then the first terminal device can determine the pattern of the second demodulation reference signal based on a third correspondence between the signal waveform, the sequence, and the pattern, and the first signal waveform and the first sequence. The third correspondence mentioned here can be a correspondence between the identifier of the signal waveform, the identifier of the sequence, and the identifier of the pattern. The third correspondence can include multiple correspondences, at least including the correspondence between the first signal waveform, the first sequence, and the pattern of the second demodulation reference signal.

[0185] This third correspondence can be understood in conjunction with Table 4 below. Each row in Table 4 represents one of the correspondences in the third correspondence.

[0186] Table 4

[0187] For example, if the first signal waveform included in the first indication information is CP-OFDM and the first sequence is sequence 1, then based on the correspondence shown in Table 4, the pattern of the second demodulation reference signal can be determined to be pattern 1. As another example, if the first signal waveform included in the first indication information is DFT-s-OFDM and the first sequence is sequence 2, then based on the correspondence shown in Table 4, the pattern of the second demodulation reference signal can be determined to be pattern 2. Furthermore, if the first signal waveform included in the first indication information is Filter SC-QAM and the first sequence is sequence 3, then based on the correspondence shown in Table 4, the pattern of the second demodulation reference signal can be determined to be pattern 3.

[0188] Regarding Tables 2, 3, and 4, the following should be noted:

[0189] For any pattern in Table 2 (e.g., pattern 1), it may be different from all the patterns shown in Table 4, or it may be the same as a certain pattern shown in Table 4 (e.g., pattern 1”). This application embodiment does not make specific limitations.

[0190] Similarly, any pattern in Table 3 (e.g., pattern 1') may be different from all the patterns shown in Table 4, or it may be the same as a certain pattern shown in Table 4 (e.g., pattern 1"). This application embodiment does not make specific limitations.

[0191] In one example, the first terminal device can determine the pattern of the first demodulation reference signal based on the port number of the aforementioned first demodulation reference signal.

[0192] Additionally, the first terminal device can generate the aforementioned first sequence. This sequence is then combined with the pattern of the first demodulation reference signal to generate a first demodulation reference signal. Based on the pattern of the second demodulation reference signal, the zero-power signal is mapped onto the resource indicated by the pattern of the second demodulation reference signal to obtain a second demodulation reference signal. This second demodulation reference signal is then sent to the network device via a first PUSCH carrying both the first and second demodulation reference signals. It should be noted that the first PUSCH carries user data in addition to the first and second demodulation reference signals.

[0193] The embodiments of this application do not specifically limit the specific implementation of the first terminal device generating the first sequence. The generation method of the first sequence can, for example, follow traditional technology, and will not be described in detail here.

[0194] S104: The network device receives the first PUSCH sent by the first terminal device.

[0195] After receiving the first PUSCH sent by the first terminal device, the network device can perform channel estimation based on the first demodulation reference signal and the second demodulation reference signal. In a specific example, the network device can estimate interference from other network devices based on the second demodulation reference signal. Specifically, since the second demodulation reference signal is a zero-power demodulation reference signal, the signals received by the network device on the frequency domain resources corresponding to the second demodulation reference signal are all interference from other terminal devices. That is, the network device can evaluate the interference from other terminal devices based on the signals received on the frequency domain resources corresponding to the second demodulation reference signal. This can be understood in conjunction with the following formula (1):

[0196] r B [k]=∑ m∈B H m [k]x m [k]+n[k] Formula (1)

[0197] In formula (1):

[0198] k represents the frequency domain resource location corresponding to the second demodulation reference signal;

[0199] B is a collection of other terminal devices;

[0200] r B [k] represents interference from other terminal devices.

[0201] Determine r B After [k], network devices can further base their systems on r. B [k] and the first demodulated reference signal are used to perform channel estimation. Since interference from other terminal devices has been confirmed during channel estimation, the network device can accurately perform channel estimation. That is, this scheme can guarantee the accuracy of channel estimation.

[0202] In this embodiment, the network device and any terminal device can interact in the manner shown in Figure 3 to perform channel estimation. In other words, the network device can also send second indication information to the second network device. This second indication information indicates a third demodulation reference signal and a fourth demodulation reference signal, where the fourth demodulation reference signal is a zero-power demodulation reference signal with zero power. Correspondingly, the second terminal device can send a second PUSCH to the network device based on the second indication information. This second PUSCH carries the third and fourth demodulation reference signals.

[0203] Regarding the third demodulation reference signal, please refer to the previous section describing the first demodulation reference signal. Regarding the fourth demodulation reference signal, please refer to the previous section describing the second demodulation reference signal; it will not be repeated here.

[0204] It should be noted here that, in order to accurately estimate the channel between the network device and each terminal device, the second demodulation reference signal indicated by the network device to each first terminal device and the fourth demodulation reference signal indicated by the network device to the second terminal device require different resources.

[0205] As an example, the fourth demodulation reference signal and the second demodulation reference signal are time-division multiplexed. This can be understood by referring to Figures (a) and (c) in Figure 4c, which is a schematic diagram of a zero-power demodulation reference signal provided in an embodiment of this application. Figure (a) in Figure 4c shows pattern 405, which can be the pattern corresponding to the second demodulation reference signal. Pattern 405 occupies the first OFDM symbol in the time domain, and its frequency RBs are numbered 0, 2, 4, ... 2p. Figure (c) in Figure 4c shows pattern 407, which can be the pattern corresponding to the fourth demodulation reference signal. Pattern 407 occupies the second OFDM symbol in the time domain, and its frequency RBs are numbered 0, 2, 4, ... 2k.

[0206] As another example, the fourth demodulation reference signal and the second demodulation reference signal occupy different resource blocks in terms of frequency. This can be understood by referring to Figures (a) and (b) in Figure 4c. Figure (a) in Figure 4c shows pattern 405, which can be the pattern corresponding to the second demodulation reference signal. Figure (b) in Figure 4c shows pattern 406, which can be the pattern corresponding to the fourth demodulation reference signal. Both patterns 405 and 406 occupy the first OFDM symbol in the time domain, but the RB numbers occupied by pattern 405 in terms of frequency are 0, 2, 4, ... 2p, while the RB numbers occupied by pattern 406 in terms of frequency are 1, 3, 5, ... 2p+1.

[0207] As another example, the fourth demodulation reference signal and the second demodulation reference signal are not only time-division multiplexed, but also occupy different resource blocks in terms of frequency. Refer to Figures (b) and (c) in Figure 4c for further understanding. In this scenario, as an example, pattern 406 shown in Figure 4c(b) can be the pattern of the second demodulation reference signal. Pattern 407 shown in Figure 4c(c) can be the pattern of the fourth demodulation reference signal. Regarding patterns 406 and 407, please refer to the relevant descriptions above; they will not be repeated here.

[0208] Furthermore, the port number used by the first terminal device to transmit the first demodulation reference signal and the port number used by the second terminal device to transmit the third demodulation reference signal can be the same. In other words, the port used by the first terminal device to transmit the first demodulation reference signal and the port used by the second terminal device to transmit the third demodulation reference signal can be non-orthogonal. That is, using the solution of this application embodiment, by introducing an additional zero-power demodulation reference signal to evaluate interference from other network devices, the ports used by different terminal devices to transmit the pre-demodulation reference signal do not need to be orthogonal.

[0209] Based on the communication methods provided in the above embodiments, this application also provides a corresponding communication device, which will be described below with reference to the accompanying drawings.

[0210] Referring to Figure 5, this application embodiment provides a communication device 500, which includes a processing unit 501 and a transceiver unit 502. The transceiver unit 502 includes a receiving unit for receiving data and a transmitting unit for sending data.

[0211] The communication device 500 can realize the functions of the terminal device (or network device) in the above method embodiments, and therefore can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device 500 can be a terminal device (or network device), or it can be an integrated circuit or component inside the terminal device (or network device), such as a chip. The following embodiments use a terminal device or network device as an example for description.

[0212] In some embodiments, the apparatus 500 is used to perform the method executed by the terminal device (e.g., the first terminal device) in the foregoing embodiments. In this case:

[0213] The receiving unit is configured to receive first indication information, the first indication information being used to indicate a first demodulation reference signal and a second demodulation reference signal, the second demodulation reference signal being a zero-power demodulation reference signal with zero power;

[0214] The transmitting unit is configured to transmit a first physical uplink shared channel (PUSCH) according to the first indication information. The first PUSCH carries the first demodulation reference signal and the second demodulation reference signal, which are used for channel estimation.

[0215] In one possible implementation, the first indication information includes: a first signal waveform corresponding to the first PUSCH and / or a first sequence corresponding to the first demodulation reference signal, wherein the first signal waveform and / or the first sequence are used to determine the pattern of the second demodulation reference signal; the processing unit 501 is used to determine the pattern of the second demodulation reference signal based on the first signal waveform and / or the first sequence before transmitting the first PUSCH.

[0216] In one possible implementation, the processing unit 501 is configured to:

[0217] Based on the first signal waveform and the first correspondence between the signal waveform and the pattern, the pattern of the second demodulation reference signal is determined, wherein the first correspondence includes at least the correspondence between the first signal waveform and the pattern of the second demodulation reference signal; or,

[0218] Based on the first sequence and the second correspondence between the sequence and the pattern, the pattern of the second demodulated reference signal is determined, wherein the second correspondence includes at least the correspondence between the first sequence and the pattern of the second demodulated reference signal; or,

[0219] The pattern of the second demodulation reference signal is determined based on the first signal waveform, the first sequence, and the third correspondence between the signal waveform, the sequence, and the pattern. The third correspondence includes at least the correspondence between the first signal waveform, the first sequence, and the pattern of the second demodulation reference signal.

[0220] In one possible implementation, the first indication information includes: a pattern index of the second demodulation reference signal, the pattern index of the second demodulation reference signal being used to determine the pattern of the second demodulation reference signal.

[0221] In one possible implementation, the first indication information includes: an index of the orthogonal frequency division multiplexing (OFDM) symbol occupied by the second demodulation reference signal; or, an index difference, wherein the index difference is the difference between the index of the OFDM symbol occupied by the first demodulation reference signal and the index of the OFDM symbol occupied by the second demodulation reference signal, and the index of the OFDM symbol or the index difference is used to indicate the pattern of the second demodulation reference signal.

[0222] In one possible implementation, the first indication information includes: the location of the frequency resource corresponding to the second demodulation reference signal, wherein: if the frequency resource corresponding to the second demodulation reference signal is sparsely mapped onto the scheduling bandwidth, the location includes: the starting frequency resource location and the sparse density; or, if the frequency resource corresponding to the second demodulation reference signal occupies at least one resource block on the scheduling bandwidth, the location includes: at least two of the following: the starting position, the ending position, and the resource block size of each resource block in the at least one resource block.

[0223] In one possible implementation, if the first signal waveform is a single-carrier waveform, the frequency resources corresponding to the second demodulation reference signal are sparsely mapped onto the scheduling bandwidth; or, if the first signal waveform is a multi-carrier waveform, the frequency resources corresponding to the second demodulation reference signal occupy at least one resource block on the scheduling bandwidth, or the frequency resources corresponding to the second demodulation reference signal are sparsely mapped onto the scheduling bandwidth.

[0224] In one possible implementation, the at least one resource block corresponds one-to-one with at least one precoded subband that is precoded.

[0225] In one possible implementation, the first demodulation reference signal includes: a pre-demodulation reference signal, or a pre-demodulation reference signal and an additional demodulation reference signal.

[0226] In one possible implementation, the first demodulation reference signal and the second demodulation reference signal are time-division multiplexed.

[0227] In one possible implementation, the non-demodulation reference signal carrier position on the OFDM symbol where the second demodulation reference signal is located is used to transmit user data.

[0228] In other embodiments, the device 500 is used to perform the methods executed by the network device in the foregoing embodiments, in which case:

[0229] The transmitting unit is used to transmit first indication information, the first indication information being used to indicate a first demodulation reference signal and a second demodulation reference signal, the second demodulation reference signal being a zero-power demodulation reference signal with zero power;

[0230] The receiving unit is configured to receive a first physical uplink shared channel (PUSCH) sent based on the first indication information. The first PUSCH carries the first demodulation reference signal and the second demodulation reference signal, which are used for channel estimation.

[0231] In one possible implementation, the first indication information includes: a first signal waveform corresponding to the first PUSCH and / or a first sequence corresponding to the first demodulation reference signal, wherein the first signal waveform and / or the first sequence are used to determine the pattern of the second demodulation reference signal.

[0232] In one possible implementation, the first indication information includes: a pattern index of the second demodulation reference signal, the pattern index of the second demodulation reference signal being used to determine the pattern of the second demodulation reference signal.

[0233] In one possible implementation, the first indication information includes: an index of the orthogonal frequency division multiplexing (OFDM) symbol occupied by the second demodulation reference signal; or, an index difference, the index difference being the difference between the index of the OFDM symbol occupied by the first demodulation reference signal and the index of the OFDM symbol occupied by the second demodulation reference signal, wherein the index of the OFDM symbol or the index difference is used to indicate the pattern of the second demodulation reference signal.

[0234] In one possible implementation, the first indication information includes: the location of the frequency resource corresponding to the second demodulation reference signal, wherein: if the frequency resource corresponding to the second demodulation reference signal is sparsely mapped onto the scheduling bandwidth, the location includes: the starting frequency resource location and the sparse density; or, if the frequency resource corresponding to the second demodulation reference signal occupies at least one resource block on the scheduling bandwidth, the location includes: at least two of the following: the starting position, the ending position, and the size of each resource block in the at least one resource block.

[0235] In one possible implementation, if the first signal waveform is a single-carrier waveform, the frequency resources corresponding to the second demodulation reference signal are sparsely mapped onto the scheduling bandwidth; or, if the first signal waveform is a multi-carrier waveform, the frequency resources corresponding to the second demodulation reference signal occupy at least one resource block on the scheduling bandwidth, or the frequency resources corresponding to the second demodulation reference signal are sparsely mapped onto the scheduling bandwidth.

[0236] In one possible implementation, the at least one resource block corresponds one-to-one with at least one precoded subband that is precoded.

[0237] In one possible implementation, the first demodulation reference signal includes: a pre-demodulation reference signal, or a pre-demodulation reference signal and an additional demodulation reference signal.

[0238] In one possible implementation, the first demodulation reference signal and the second demodulation reference signal are time-division multiplexed.

[0239] In one possible implementation, the non-demodulation reference signal carrier position on the OFDM symbol where the second demodulation reference signal is located is used to transmit user data.

[0240] In one possible implementation, the transmitting unit is further configured to: transmit second indication information, the second indication information being used to indicate a third demodulation reference signal and a fourth demodulation reference signal, the fourth demodulation reference signal being a zero-power demodulation reference signal with zero power, wherein: the port number used to transmit the third demodulation reference signal is the same as the port number used to transmit the first demodulation reference signal; the receiving unit is further configured to receive a second PUSCH transmitted based on the second indication information, the second PUSCH carrying the third demodulation reference signal and the fourth demodulation reference signal, the third demodulation reference signal and the fourth demodulation reference signal being used for channel estimation; wherein: the fourth demodulation reference signal and the second demodulation reference signal are time-division multiplexed, and / or, the fourth demodulation reference signal and the second demodulation reference signal occupy different resource blocks in terms of frequency.

[0241] It should be noted that the information execution process of the unit of the above-mentioned communication device 500 can be specifically described in the method embodiment shown above in this application, and will not be repeated here.

[0242] Please refer to Figure 6, which is a schematic diagram of another communication device provided in this application. The communication device 600 includes a logic circuit 601 and an input / output interface 602. The communication device 600 can be a chip or an integrated circuit.

[0243] The communication device 600 can realize the functions of the terminal device (or network device) in the above method embodiments, and therefore can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device 600 can be a terminal device (or network device), or it can be an integrated circuit or component inside the terminal device (or network device), such as a chip. The following embodiments use a terminal device or network device as an example for description.

[0244] In Figure 5, the transceiver unit 502 can be a communication interface, which can be the input / output interface 602 in Figure 6, and the input / output interface 602 can include an input interface and an output interface. Alternatively, the communication interface can also be a transceiver circuit, which can include an input interface circuit and an output interface circuit.

[0245] In one possible implementation, when the device 600 is used to perform the method executed by the terminal device (e.g., the first terminal device) in the foregoing embodiments: the input / output interface 602 is used to receive first indication information, the first indication information being used to indicate a first demodulation reference signal and a second demodulation reference signal, the second demodulation reference signal being a zero-power demodulation reference signal with zero power; according to the first indication information, a first physical uplink shared channel (PUSCH) is transmitted, the first PUSCH carrying the first demodulation reference signal and the second demodulation reference signal, the first demodulation reference signal and the second demodulation reference signal being used for channel estimation; in one example, the logic circuit 601 is used to determine the pattern of the second demodulation reference signal based on the first signal waveform and / or the first sequence before transmitting the first PUSCH.

[0246] The logic circuit 601 and the input / output interface 602 can also perform other steps executed by the terminal device in the aforementioned embodiments and achieve corresponding beneficial effects, which will not be elaborated here.

[0247] In one possible implementation, when the device 600 is used to perform the method executed by the network device in the foregoing embodiments: the input / output interface 602 is used to send first indication information, the first indication information being used to indicate a first demodulation reference signal and a second demodulation reference signal, the second demodulation reference signal being a zero-power demodulation reference signal with zero power; and to receive a first Physical Uplink Shared Channel (PUSCH) sent based on the first indication information, the first PUSCH carrying the first demodulation reference signal and the second demodulation reference signal, the first demodulation reference signal and the second demodulation reference signal being used for channel estimation. In one example, the logic circuit 601 is used to perform channel estimation based on the first demodulation reference signal and the second demodulation reference signal.

[0248] The logic circuit 601 and the input / output interface 602 can also perform other steps executed by the network device in the aforementioned embodiments and achieve corresponding beneficial effects, which will not be elaborated here.

[0249] In one possible implementation, the processing unit 501 shown in FIG5 can be the logic circuit 601 in FIG6.

[0250] Optionally, the logic circuit 601 can be a processing device, the functions of which can be partially or entirely implemented in software.

[0251] Optionally, the processing apparatus may include a memory and a processor, wherein the memory is used to store a computer program, and the processor reads and executes the computer program stored in the memory to perform the corresponding processing and / or steps in any of the method embodiments.

[0252] Optionally, the processing device may consist of only a processor. A memory for storing computer programs is located outside the processing device, and the processor is connected to the memory via circuitry / wires to read and execute the computer programs stored in the memory. The memory and processor may be integrated together or physically independent of each other.

[0253] Optionally, the processing device may be one or more chips, or one or more integrated circuits. For example, the processing device may be one or more field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), system-on-chips (SoCs), central processing units (CPUs), network processors (NPs), digital signal processors (DSPs), microcontroller units (MCUs), programmable logic devices (PLDs), or other integrated chips, or any combination of the above chips or processors.

[0254] Please refer to Figure 7, which shows the communication device 700 involved in the above embodiments provided in the embodiments of this application. The communication device 700 may include, but is not limited to, at least one processor 701 and a communication port 702.

[0255] Further optionally, the device may also include at least one of a memory 703 and a bus 704. In the embodiments of this application, the at least one processor 701 is used to control the operation of the communication device 700.

[0256] Furthermore, the processor 701 can be a central processing unit, a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field-programmable gate array, or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processor can also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a digital signal processor and a microprocessor, etc. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0257] The communication device 700 can implement the functions of the terminal device (or network device) in the above method embodiments. In the embodiments of this application, the communication device 700 can be a terminal device (or network device), or it can be an integrated circuit or component inside the terminal device (or network device), such as a chip. The specific implementation of the communication device shown in FIG7 can be referred to the description in the foregoing method embodiments, and will not be repeated here.

[0258] Please refer to Figure 8, which is a schematic diagram of the structure of the communication device 800 involved in the above embodiments provided in this application.

[0259] The communication device 800 can realize the functions of the terminal device (or network device) in the above method embodiments, and therefore can also achieve the beneficial effects of the above method embodiments. In the embodiments of this application, the communication device 800 can be a terminal device (or network device), or it can be an integrated circuit or component inside the terminal device (or network device), such as a chip.

[0260] The communication device 800 includes at least one processor 811 and at least one network interface 814. Optionally, the communication device further includes at least one memory 812, at least one transceiver 813, and one or more antennas 815. The processor 811, memory 812, transceiver 813, and network interface 814 are connected, for example, via a bus. In this embodiment, the connection may include various interfaces, transmission lines, or buses, etc., and this embodiment is not limited thereto. The antenna 815 is connected to the transceiver 813. The network interface 814 enables the communication device to communicate with other communication devices through a communication link. For example, the network interface 814 may include a network interface between the communication device and core network equipment, such as an S1 interface, or a network interface between the communication device and other communication devices (e.g., other network devices or core network equipment), such as an X2 or Xn interface.

[0261] The processor 811 is primarily used to process communication protocols and communication data, control the entire communication device, execute software programs, and process data from these programs, for example, to support the actions described in the embodiments of the communication device. The communication device may include a baseband processor and a central processing unit (CPU). The baseband processor is primarily used to process communication protocols and communication data, while the CPU is primarily used to control the entire terminal device, execute software programs, and process data from these programs. The processor 811 in Figure 8 can integrate the functions of both a baseband processor and a CPU. Those skilled in the art will understand that the baseband processor and CPU can also be independent processors interconnected via technologies such as buses. Those skilled in the art will understand that a terminal device may include multiple baseband processors to adapt to different network standards, and multiple CPUs to enhance its processing capabilities. The various components of the terminal device can be connected via various buses. The baseband processor can also be described as a baseband processing circuit or a baseband processing chip. The CPU can also be described as a central processing circuit or a central processing chip. The function of processing communication protocols and communication data can be built into the processor or stored in memory as a software program, which is then executed by the processor to implement the baseband processing function.

[0262] The memory is primarily used to store software programs and data. The memory 812 can exist independently or be connected to the processor 811. Optionally, the memory 812 can be integrated with the processor 811, for example, integrated into a single chip. The memory 812 can store program code that executes the technical solutions of the embodiments of this application, and its execution is controlled by the processor 811. The various types of computer program code being executed can also be considered as drivers for the processor 811.

[0263] Figure 8 shows only one memory and one processor. In actual terminal devices, there may be multiple processors and multiple memories. Memory can also be called storage medium or storage device, etc. Memory can be a storage element on the same chip as the processor, i.e., an on-chip storage element, or it can be a separate storage element; this application does not limit this.

[0264] Transceiver 813 can be used to support the reception or transmission of radio frequency (RF) signals between a communication device and a terminal. Transceiver 813 can be connected to antenna 815. Transceiver 813 includes a transmitter Tx and a receiver Rx. Specifically, one or more antennas 815 can receive RF signals. The receiver Rx of transceiver 813 receives the RF signals from the antennas, converts the RF signals into digital baseband signals or digital intermediate frequency (IF) signals, and provides the digital baseband signals or IF signals to processor 811 so that processor 811 can perform further processing on the digital baseband signals or IF signals, such as demodulation and decoding. Furthermore, the transmitter Tx in transceiver 813 is also used to receive modulated digital baseband signals or IF signals from processor 811, convert the modulated digital baseband signals or IF signals into RF signals, and transmit the RF signals through one or more antennas 815. Specifically, the receiver Rx can selectively perform one or more stages of downmixing and analog-to-digital conversion on the radio frequency signal to obtain a digital baseband signal or a digital intermediate frequency (IF) signal. The order of these downmixing and IF conversion processes is adjustable. The transmitter Tx can selectively perform one or more stages of upmixing and digital-to-analog conversion on the modulated digital baseband signal or digital IF signal to obtain a radio frequency signal. The order of these upmixing and IF conversion processes is also adjustable. The digital baseband signal and the digital IF signal can be collectively referred to as digital signals.

[0265] The transceiver 813 can also be called a transceiver unit, transceiver, transceiver device, etc. Optionally, the device in the transceiver unit that performs the receiving function can be regarded as the receiving unit, and the device in the transceiver unit that performs the transmitting function can be regarded as the transmitting unit. That is, the transceiver unit includes a receiving unit and a transmitting unit. The receiving unit can also be called a receiver, input port, receiving circuit, etc., and the transmitting unit can be called a transmitter, transmitter, or transmitting circuit, etc.

[0266] It should be noted that the communication device 800 shown in Figure 8 can be used to implement the steps implemented by the terminal device (or network device) in the aforementioned method embodiments, and to achieve the technical effects corresponding to the network device. The specific implementation of the communication device 800 shown in Figure 8 can be referred to the description in the aforementioned method embodiments, and will not be repeated here.

[0267] This application also provides a computer-readable storage medium for storing one or more computer-executable instructions. When the computer-executable instructions are executed by a processor, the processor performs the method described in the possible implementation of the communication device (e.g., a first terminal device or a network device) as described in the foregoing embodiments.

[0268] This application also provides a computer program product (or computer program) that, when executed by a processor, allows the processor to execute a method that may implement the aforementioned communication device (e.g., a first terminal device or network device).

[0269] This application also provides a chip system including at least one processor for supporting a communication device in implementing the functions involved in the possible implementations of the communication device described above. Optionally, the chip system further includes an interface circuit that provides program instructions and / or data to the at least one processor. In one possible design, the chip system may also include a memory for storing the program instructions and data necessary for the communication device. The chip system may be composed of chips or may include chips and other discrete devices, wherein the communication device may specifically be a terminal device or a network device as described in the foregoing method embodiments.

[0270] This application also provides a communication system, the network system architecture of which includes terminal devices (e.g., a first terminal device and / or a second terminal device) and network devices as described in any of the above embodiments.

[0271] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0272] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0273] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

A communication method characterized by comprising: The method comprises: receiving first indication information, the first indication information being used for indicating a first demodulation reference signal and a second demodulation reference signal, the second demodulation reference signal being a zero-power demodulation reference signal with a power of 0; according to the first indication information, transmitting a first physical uplink shared channel (PUSCH), the first PUSCH carrying the first demodulation reference signal and the second demodulation reference signal, the first demodulation reference signal and the second demodulation reference signal being used for channel estimation. The method of claim 1, wherein The first indication information comprises: a first signal waveform corresponding to the first PUSCH and / or a first sequence corresponding to the first demodulation reference signal, the first signal waveform and / or the first sequence being used for determining a pattern of the second demodulation reference signal; Before transmitting the first PUSCH, the method further comprises: determining the pattern of the second demodulation reference signal according to the first signal waveform and / or the first sequence. The method according to claim 2, characterized in that The determining the pattern of the second demodulation reference signal according to the first signal waveform and / or the first sequence comprises: determining the pattern of the second demodulation reference signal according to the first signal waveform and a first correspondence relationship between a signal waveform and a pattern, the first correspondence relationship at least comprising a correspondence relationship between the first signal waveform and the pattern of the second demodulation reference signal; or determining the pattern of the second demodulation reference signal according to the first sequence and a second correspondence relationship between a sequence and a pattern, the second correspondence relationship at least comprising a correspondence relationship between the first sequence and the pattern of the second demodulation reference signal; or determining the pattern of the second demodulation reference signal according to the first signal waveform, the first sequence, and a third correspondence relationship among a signal waveform, a sequence, and a pattern, the third correspondence relationship at least comprising a correspondence relationship among the first signal waveform, the first sequence, and the pattern of the second demodulation reference signal. The method of claim 1, wherein The first indication information comprises: a pattern index of the second demodulation reference signal, the pattern index of the second demodulation reference signal being used for determining the pattern of the second demodulation reference signal. The method of claim 1, wherein The first indication information comprises: an index of an orthogonal frequency division multiplexing (OFDM) symbol occupied by the second demodulation reference signal; or an index difference, the index difference being a difference between an index of an OFDM symbol occupied by the first demodulation reference signal and an index of an OFDM symbol occupied by the second demodulation reference signal, the index of the OFDM symbol or the index difference being used for indicating the pattern of the second demodulation reference signal. The method according to claim 1 or 5, characterized in that The first indication information comprises: a location of a frequency resource corresponding to the second demodulation reference signal, wherein: if frequency resources corresponding to the second demodulation reference signal are sparsely mapped on a scheduling bandwidth, the location comprises: a starting frequency resource location and a sparsity density; or If the frequency resource corresponding to the second demodulation reference signal occupies at least one resource block on the scheduling bandwidth, the position comprises at least two of a starting position, an ending position and a resource block size of each of the at least one resource block. The method of claim 6, wherein, If the first signal waveform is a single-carrier waveform, the frequency resource corresponding to the second demodulation reference signal is sparsely mapped on the scheduling bandwidth; or, If the first signal waveform is a multi-carrier waveform, the frequency resource corresponding to the second demodulation reference signal occupies at least one resource block on the scheduling bandwidth, or the frequency resource corresponding to the second demodulation reference signal is sparsely mapped on the scheduling bandwidth. The method according to claim 6 or 7, characterized in that The at least one resource block corresponds to at least one precoding sub-band on a one-to-one basis. The method according to any one of claims 1 to 8, characterized in that The first demodulation reference signal comprises a front-loaded demodulation reference signal, or a front-loaded demodulation reference signal and an additional demodulation reference signal. The method according to any one of claims 1 to 9, characterized in that The first demodulation reference signal and the second demodulation reference signal are time-division. The method according to any one of claims 1 to 10, characterized in that A non-demodulation reference signal carrier position on an OFDM symbol where the second demodulation reference signal is located is used to transmit user data. A communication method characterized by comprising: The method comprises: sending first indication information, the first indication information being used to indicate a first demodulation reference signal and a second demodulation reference signal, the second demodulation reference signal being a zero-power demodulation reference signal with a power of 0; receiving a first physical uplink shared channel (PUSCH) sent based on the first indication information, the first PUSCH carrying the first demodulation reference signal and the second demodulation reference signal, the first demodulation reference signal and the second demodulation reference signal being used for channel estimation. The method of claim 12, wherein The first indication information comprises: a first signal waveform corresponding to the first PUSCH and / or a first sequence corresponding to the first demodulation reference signal, the first signal waveform and / or the first sequence being used to determine a pattern of the second demodulation reference signal. The method according to claim 12, characterized in that, The first indication information comprises: a pattern index of the second demodulation reference signal, the pattern index of the second demodulation reference signal being used to determine a pattern of the second demodulation reference signal. The method of claim 12, wherein The first indication information comprises: an index of an orthogonal frequency division multiplexing (OFDM) symbol occupied by the second demodulation reference signal, or an index difference between an index of an OFDM symbol occupied by the first demodulation reference signal and an index of an OFDM symbol occupied by the second demodulation reference signal, the index of the OFDM symbol or the index difference being used to indicate the pattern of the second demodulation reference signal. The method according to claim 12 or 15, characterized in that The first indication information comprises: a position of a frequency resource corresponding to the second demodulation reference signal, wherein: if the frequency resource corresponding to the second demodulation reference signal is sparsely mapped on the scheduling bandwidth, the position comprises a starting frequency resource position and a sparsity density; or, If the frequency resource corresponding to the second demodulation reference signal occupies at least one resource block on the scheduling bandwidth, the position comprises at least two of a starting position, an ending position and a size of each of the at least one resource block. The method of claim 16, wherein, If the first signal waveform is a single-carrier waveform, the frequency resource corresponding to the second demodulation reference signal is sparsely mapped on the scheduling bandwidth; or, If the first signal waveform is a multi-carrier waveform, the frequency resource corresponding to the second demodulation reference signal occupies at least one resource block on the scheduling bandwidth, or the frequency resource corresponding to the second demodulation reference signal is sparsely mapped on the scheduling bandwidth. The method according to claim 16 or 17, characterized in that The at least one resource block corresponds to at least one precoding sub-band on a one-to-one basis. The method according to any one of claims 12-18, characterized in that The first demodulation reference signal comprises a front-loaded demodulation reference signal, or a front-loaded demodulation reference signal and an additional demodulation reference signal. The method according to any one of claims 12-19, characterized in that The first demodulation reference signal and the second demodulation reference signal are time-division. The method according to any one of claims 12-20, characterized in that A non-demodulation reference signal carrier position on an OFDM symbol where the second demodulation reference signal is located is used to transmit user data. The method according to any one of claims 12-21, characterized in that The method further comprises: sending second indication information, the second indication information being used to indicate a third demodulation reference signal and a fourth demodulation reference signal, the fourth demodulation reference signal being a zero-power demodulation reference signal with a power of 0, wherein a port number used to send the third demodulation reference signal is the same as a port number used to send the first demodulation reference signal; receiving a second PUSCH sent based on the second indication information, the second PUSCH carrying the third demodulation reference signal and the fourth demodulation reference signal, the third demodulation reference signal and the fourth demodulation reference signal being used for channel estimation; wherein: The fourth demodulation reference signal and the second demodulation reference signal are time-division, and / or the fourth demodulation reference signal and the second demodulation reference signal occupy different resource blocks in frequency. A communication device, characterized by A module for performing the method of any one of claims 1 to 22. A communication device, characterized by At least one processor coupled with a memory, the at least one processor being configured to perform the method of any one of claims 1 to 22. A readable storage medium characterized in that, The storage medium has stored therein a computer program or instructions, which, when executed by a communication device, cause the communication device to implement the method of any one of claims 1 to 22. A computer program product, characterized in that The computer program product contains instructions or a computer program, which, when run on a computer, cause the computer to perform the method of any one of claims 1 to 22. A communication device, characterized by The apparatus comprises: a receiving unit configured to receive first indication information, the first indication information being used to indicate a first demodulation reference signal and a second demodulation reference signal, the second demodulation reference signal being a zero-power demodulation reference signal with a power of 0; The sending unit is configured to send a first physical uplink shared channel (PUSCH) according to the first indication information, the first PUSCH carrying the first demodulation reference signal and the second demodulation reference signal, and the first demodulation reference signal and the second demodulation reference signal being used for channel estimation. The apparatus of claim 27, wherein The first indication information comprises: The first signal waveform corresponding to the first PUSCH and / or the first sequence corresponding to the first demodulation reference signal are used for determining the pattern of the second demodulation reference signal. The apparatus further comprises a processing unit configured to determine the pattern of the second demodulation reference signal according to the first signal waveform and / or the first sequence before sending the first PUSCH. The apparatus of claim 28, wherein The processing unit is configured to: determine the pattern of the second demodulation reference signal according to the first signal waveform and a first correspondence relationship between a signal waveform and a pattern, the first correspondence relationship at least comprising a correspondence relationship between the first signal waveform and the pattern of the second demodulation reference signal; or, determine the pattern of the second demodulation reference signal according to the first sequence and a second correspondence relationship between a sequence and a pattern, the second correspondence relationship at least comprising a correspondence relationship between the first sequence and the pattern of the second demodulation reference signal; or, determine the pattern of the second demodulation reference signal according to the first signal waveform, the first sequence, and a third correspondence relationship between a signal waveform, a sequence, and a pattern, the third correspondence relationship at least comprising a correspondence relationship between the first signal waveform, the first sequence, and the pattern of the second demodulation reference signal. The apparatus of claim 27, wherein The first indication information comprises: a pattern index of the second demodulation reference signal, the pattern index of the second demodulation reference signal being used for determining the pattern of the second demodulation reference signal. The apparatus of claim 27, wherein The first indication information comprises: an index of an orthogonal frequency division multiplexing (OFDM) symbol occupied by the second demodulation reference signal, or an index difference value, the index difference value being a difference value between an index of an OFDM symbol occupied by the first demodulation reference signal and an index of an OFDM symbol occupied by the second demodulation reference signal, the index of the OFDM symbol or the index difference value being used for indicating the pattern of the second demodulation reference signal. The apparatus of claim 27 or 31, wherein The first indication information comprises: a location of a frequency resource corresponding to the second demodulation reference signal, wherein: if frequency resources corresponding to the second demodulation reference signal are sparsely mapped on a scheduling bandwidth, the location comprises a starting frequency resource location and a sparsity density; or, if the frequency resources corresponding to the second demodulation reference signal occupy at least one resource block on the scheduling bandwidth, the location comprises at least two of a starting location, an ending location, and a resource block size of each resource block in the at least one resource block. The apparatus according to claim 32, wherein: if the first signal waveform is a single-carrier waveform, the frequency resources corresponding to the second demodulation reference signal are sparsely mapped on a scheduling bandwidth; or, If the first signal waveform is a multi-carrier waveform, the frequency resource corresponding to the second demodulation reference signal occupies at least one resource block on the scheduling bandwidth, or the frequency resource corresponding to the second demodulation reference signal is sparsely mapped on the scheduling bandwidth. The apparatus of claim 32 or 33, wherein The at least one resource block corresponds to at least one precoding sub-band for precoding in a one-to-one manner. The apparatus of any of claims 27-34, wherein The first demodulation reference signal includes a front demodulation reference signal or a front demodulation reference signal and an additional demodulation reference signal. The apparatus of any of claims 27-35, wherein The first demodulation reference signal and the second demodulation reference signal are time-division. The apparatus of any of claims 27-36, wherein The non-demodulation reference signal carrier position on the OFDM symbol where the second demodulation reference signal is located is used to transmit user data. A communication device, characterized by The apparatus comprises: A sending unit configured to send first indication information, the first indication information being used to indicate a first demodulation reference signal and a second demodulation reference signal, the second demodulation reference signal being a zero-power demodulation reference signal with a power of 0; A receiving unit configured to receive a first physical uplink shared channel (PUSCH) sent based on the first indication information, the first PUSCH carrying the first demodulation reference signal and the second demodulation reference signal, the first demodulation reference signal and the second demodulation reference signal being used for channel estimation. The apparatus of claim 38, wherein The first indication information includes: A first signal waveform corresponding to the first PUSCH and / or a first sequence corresponding to the first demodulation reference signal, the first signal waveform and / or the first sequence being used to determine a pattern of the second demodulation reference signal. The apparatus of claim 38, wherein The first indication information includes: A pattern index of the second demodulation reference signal, the pattern index of the second demodulation reference signal being used to determine a pattern of the second demodulation reference signal. The apparatus of claim 38, wherein The first indication information includes: An index of an orthogonal frequency division multiplexing (OFDM) symbol occupied by the second demodulation reference signal, or an index difference between an index of an OFDM symbol occupied by the first demodulation reference signal and an index of an OFDM symbol occupied by the second demodulation reference signal, the index or the index difference being used to indicate a pattern of the second demodulation reference signal. The apparatus of claim 38 or 41, wherein The first indication information includes: A position of a frequency resource corresponding to the second demodulation reference signal, wherein: If the frequency resource corresponding to the second demodulation reference signal is sparsely mapped on the scheduling bandwidth, the position includes a starting frequency resource position and a sparsity density; or If the frequency resource corresponding to the second demodulation reference signal occupies at least one resource block on the scheduling bandwidth, the position includes at least two of a starting position, an ending position, and a size of each resource block in the at least one resource block. The apparatus according to claim 42, wherein: If the first signal waveform is a single-carrier waveform, the frequency resource corresponding to the second demodulation reference signal is sparsely mapped on the scheduling bandwidth; or If the first signal waveform is a multi-carrier waveform, the frequency resource corresponding to the second demodulation reference signal occupies at least one resource block on the scheduling bandwidth, or the frequency resource corresponding to the second demodulation reference signal is sparsely mapped on the scheduling bandwidth. The apparatus of claim 42 or 43, wherein The at least one resource block corresponds to at least one precoding sub-band for precoding in a one-to-one manner. The apparatus of any one of claims 38-44, wherein The first demodulation reference signal comprises a front demodulation reference signal or a front demodulation reference signal and an additional demodulation reference signal. The apparatus of any of claims 38-45, wherein The first demodulation reference signal and the second demodulation reference signal are time-division. The apparatus of any of claims 38-46, wherein The non-demodulation reference signal carrier position on the OFDM symbol where the second demodulation reference signal is located is used to transmit user data. The apparatus according to any one of claims 38-47, characterized in that, The sending unit is further configured to send second indication information, the second indication information being used to indicate a third demodulation reference signal and a fourth demodulation reference signal, the fourth demodulation reference signal being a zero-power demodulation reference signal with a power of 0, wherein a port number used to send the third demodulation reference signal is the same as a port number used to send the first demodulation reference signal. The receiving unit is further configured to receive a second PUSCH sent based on the second indication information, the second PUSCH carrying the third demodulation reference signal and the fourth demodulation reference signal, the third demodulation reference signal and the fourth demodulation reference signal being used to perform channel estimation; wherein: The fourth demodulation reference signal and the second demodulation reference signal are time-division, and / or the fourth demodulation reference signal and the second demodulation reference signal occupy different resource blocks in frequency.

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