CN115733591A

CN115733591A - Downlink transmission method and related device based on multi-station cooperation

Info

Publication number: CN115733591A
Application number: CN202111005796.6A
Authority: CN
Inventors: 刘显达
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-08-30
Filing date: 2021-08-30
Publication date: 2023-03-03
Also published as: WO2023030063A1

Abstract

The embodiment of the application discloses a downlink transmission method and a related device based on multi-station cooperation, wherein the method comprises the following steps: the method comprises the steps that terminal equipment receives first indication information sent by network equipment; the first indication information indicates a plurality of reference signals having a quasi-co-located QCL relationship with the first signal, and QCL weights for each of the plurality of reference signals; receiving a first signal according to a first channel large-scale parameter; the first channel large-scale parameter is obtained by synthesizing a plurality of channel large-scale parameters estimated from a plurality of reference signals by using QCL weight of each reference signal in the plurality of reference signals. The first channel large-scale parameter is obtained by synthesizing the plurality of channel large-scale parameters estimated by the plurality of reference signals by using the QCL weight of each reference signal in the plurality of reference signals, so that the first channel large-scale parameter can more accurately reflect the channel state experienced by a subsequent first signal, and the first signal is more accurately received.

Description

Downlink transmission method and related device based on multi-station cooperation

Technical Field

The present application relates to the field of communications, and in particular, to a downlink transmission method and a related apparatus based on multi-station cooperation.

Background

When a network device (e.g., a base station) schedules downlink transmission, it needs to indicate a quasi co-location (QCL) hypothesis of a demodulation reference signal (DMRS) corresponding to the downlink transmission. The QCL is assumed to assist a User Equipment (UE) in receiving the DMRS. For example, the UE may determine a crystal frequency for receiving the DMRS through doppler shift (doppler shift) indication information included in the QCL hypothesis, so as to align the crystal frequency of the network device to avoid inter-carrier interference (ICI) generated by the received signal, and thus, the reception performance is lost. For another example, the UE may determine the receiving time of the DMRS through the average delay (averaging delay) indication information included in the QCL hypothesis, so as to compensate for the transmission delay caused by the propagation path to avoid Inter Symbol Interference (ISI) of the received signal, and thus, the receiving performance is lost. For another example, the UE may further determine, through delay spread (delay spread) and doppler spread (doppler spread) indication information included in the QCL hypothesis, a wiener filter coefficient used for receiving the DMRS to estimate a channel more accurately, so as to demodulate data correctly. Currently, the above indication information is indicated by configuring a QCL relationship between a DMRS and another Reference Signal (RS). The parameters related to the doppler shift and the delay can be estimated in advance through measurement on another RS, and the large-scale characteristics of the channel under the propagation environment of another RS and the propagation environment of the DMRS are assumed to be unchanged, so that the estimated parameters can be applied to DMRS reception.

Multiple transmission reception point (multiple-TRP) cooperative transmission: and the plurality of transmission nodes complete data scheduling and transmission on the same UE in a cooperative scheduling mode. For example, a plurality of transmission nodes may be connected to a central scheduler through optical fibers, so that data transmission of the plurality of transmission nodes may be uniformly scheduled in a cooperative manner. The throughput of the whole network and the rate of UE at the edge of a cell can be improved through the cooperative transmission of multiple transmission receiving points. In a multi-transmission reception point cooperative transmission scenario, a large channel scale experienced by a signal (e.g., DMRS) received by a UE is synthesized by transmission paths of two or more Transmission Reception Points (TRPs). How to accurately receive a signal whose channel large scale is synthesized by transmission paths of two or more transmission reception points TRP is a subject of current research.

Disclosure of Invention

The embodiment of the application discloses a downlink transmission method based on multi-station cooperation and a related device.

In a first aspect, an embodiment of the present application provides a downlink transmission method based on multi-station cooperation, where the method includes: the method comprises the steps that terminal equipment receives first indication information sent by network equipment; the first indication information indicates a plurality of reference signals having a quasi-co-located QCL relationship with a first signal and a QCL weight for each of the plurality of reference signals; receiving the first signal according to a first channel large-scale parameter; the first channel large-scale parameter is obtained using the plurality of reference signals and QCL weights for each of the plurality of reference signals. In this application, QCL relationships may be referred to as QCL assumptions.

In the embodiment of the application, the first signal is received according to the first channel large-scale parameter. Since the first channel large-scale parameter is obtained by using the plurality of reference signals and the QCL weight of each of the plurality of reference signals, the first channel large-scale parameter can more accurately reflect the channel state experienced by the subsequent first signal, thereby more accurately receiving the first signal.

In a possible implementation manner, the first signal is carried on one DMRS port, or the first signal is carried on one PDSCH port, or the first signal is carried on one PDCCH port.

In this implementation, the first signal is carried on one DMRS port, PDSCH port, or PDCCH port. The multiple reference signals are used as QCL hypothesis indications of the first signals loaded on the same DMRS port, PDSCH port or PDCCH port. Therefore, the UE synthesizes the large-scale parameters estimated by the plurality of reference signals to obtain the channel large-scale parameters of the first signal.

In one possible implementation, the plurality of reference signals and the first signal each correspond to a first frequency band and a first transmission layer; or, the plurality of reference signals and the first signal each correspond to a first frequency band and a first data stream; alternatively, the plurality of reference signals and the first signal each correspond to a first transport layer and a first data stream.

Considering that there may be a large difference in power allocation of Transmission Reception Point (TRP) transmission data in each frequency band in cooperative scheduling, the QCL weight may be indicated independently for each frequency band. The granularity of the frequency bands may be: a physical resource block group (PRG) or a PRG group. The PRG group refers to a plurality of PRGs (a group of PRGs). In some embodiments, the ID of the Reference Signal (RS) of the QCL hypothesis may be independently indicated on each frequency band. Still further, considering that there may be a large difference in power allocation of each TRP transmission data in each transport layer in cooperative scheduling, the QCL weight may also be indicated independently for each transport layer. In some embodiments, the ID of the RS of the QCL hypothesis may be indicated independently on each transport layer. Still further, for transmission over a Physical Downlink Shared Channel (PDSCH), multiple codewords (codewords) may exist. One codeword corresponds to a Modulation and Coding Scheme (MCS). Different codewords may correspond to different MCSs. Different codewords may correspond to different transmission layers. The codewords are used to characterize the granularity of the channel coding. In some embodiments, it may also be possible that each codeword (i.e. data stream) indicates QCL assumption independently, taking into account that the MCS difference of different codewords mainly results from the inter-stream power allocation of the TRP.

In this implementation, the plurality of reference signals and the first signal correspond not only to the same frequency band but also to the same transmission layer or data stream. The channel large-scale parameter obtained based on the multiple reference signals can better reflect the channel state experienced by the first signal.

In one possible implementation, the bandwidth occupied by the first signal includes a plurality of second frequency bands, and the QCL relationship between the first signal and the plurality of reference signals includes a QCL relationship between each second frequency band and at least one of the plurality of reference signals.

In this implementation, the QCL relationship between the first signal and the plurality of reference signals includes a QCL relationship between each second frequency band and at least one of the plurality of reference signals. The channel large-scale parameter of each second frequency band can be more accurately estimated according to the QCL relationship between each second frequency band and the reference signal.

In one possible implementation, the first indication information indicates a plurality of reference signals having a QCL relationship with the first signal, and the QCL weight of each of the plurality of reference signals includes: the first indication information indicates a plurality of first Transmission Control Indication (TCI) states, the plurality of first TCI states correspond to the plurality of reference signals one to one, and each of the first TCI states further includes QCL weights of the reference signals corresponding to the first TCI states.

In this implementation, the first indication information indicates the first TCI state with little resource overhead.

In one possible implementation, the first indication information includes a plurality of identifiers and a plurality of QCL weights, the identifiers are identifiers of the reference signals, the identifiers have one-to-one correspondence with the QCL weights, and the QCL weights represent ratios of values of QCL hypothesis parameters generated by the reference signals to values of QCL hypothesis parameters when the QCL hypothesis is synthesized.

In this implementation, the plurality of identities and the plurality of QCL weights included in the first indication information may accurately characterize a ratio of values of QCL hypothesis parameters generated from the plurality of reference signals to values of QCL hypothesis when synthesizing the QCL hypothesis.

In one possible implementation, the plurality of reference signals and the first signal each correspond to a first frequency band, a first transmission layer, and a first data stream.

In this implementation, the first indication information indicates inter-stream, inter-transport layer, and inter-band power allocation so that a power delay spectrum based on the multiple reference signals can better reflect a channel state experienced by the first signal.

In one possible implementation, before receiving the first signal according to a first channel large-scale parameter, the method further includes: receiving the plurality of reference signals; estimating channel large-scale parameters by using the plurality of reference signals respectively to obtain a plurality of channel large-scale parameters; and synthesizing the plurality of channel large-scale parameters by using the QCL weight of each reference signal in the plurality of reference signals to obtain the first channel large-scale parameter.

In the implementation mode, the QCL weight of each reference signal in the multiple reference signals is used for synthesizing the multiple channel large-scale parameters to obtain the first channel large-scale parameter. Because the power distribution among streams, transmission layers and frequency bands is considered, the large-scale parameter of the first channel can accurately reflect the channel state of the first signal, and the performance of receiving the first signal is further improved.

In one possible implementation manner, the first signal is a demodulation reference signal DMRS or a channel state information reference signal CSI-RS, and the plurality of reference signals are different tracking reference signals TRS.

In one possible implementation manner, the method is applied to a downlink transmission scenario of multi-TRP cooperative transmission.

In a second aspect, an embodiment of the present application provides a downlink transmission method based on multi-station cooperation, where the method includes: generating, by a network device, first indication information indicating a plurality of reference signals having a quasi-co-located QCL relationship with a first signal and a QCL weight for each of the plurality of reference signals; sending the first indication information to terminal equipment; the first indication information is used for the terminal equipment to receive the first signal.

In the embodiment of the application, the network device sends the first indication information to the terminal device, so that the terminal device synthesizes the multiple channel large-scale parameters estimated from the multiple reference signals by using the QCL weight of each of the multiple reference signals, and obtains the first channel large-scale parameters capable of accurately reflecting the channel state experienced by the subsequent first signal.

In this implementation, the first signal is carried on one DMRS port, PDSCH port, or PDCCH port. The multiple reference signals are QCL hypothesis indications of a first signal carried on the same DMRS port, PDSCH port or PDCCH port. Therefore, the UE synthesizes the large-scale parameters estimated by the multiple reference signals to obtain the channel large-scale parameter of the first signal.

In this implementation, the QCL relationship between the first signal and the plurality of reference signals includes QCL relationships between each of the second frequency bands and at least one of the plurality of reference signals. The channel large-scale parameter of each second frequency band can be more accurately estimated according to the QCL relationship between each second frequency band and the reference signal.

In this implementation, the first indication information indicates the first TCI status with little resource overhead.

In a third aspect, an embodiment of the present application provides a communication method, where the method includes: receiving a first demodulation reference signal (DMRS) sent by network equipment; receiving a second signal according to the second channel large-scale parameter; the second channel large-scale parameter is obtained based on the channel large-scale parameter of the first DMRS; the second signal is a reference signal having a QCL relationship with the first DMRS.

In the embodiment of the application, a second signal is received according to a second channel large-scale parameter; on the premise of not influencing the data receiving performance, the QCL assumption can be estimated through the DMRS without relying on a Tracking Reference Signal (TRS), and the signaling overhead is reduced.

In one possible implementation manner, the bandwidth of the first DMRS is greater than a bandwidth threshold, or the first DMRS includes K DMRS transmission symbols in one slot and a time interval between any two DMRS transmission symbols is greater than a time threshold, where K is an integer greater than 1.

In this implementation, the bandwidth of the first DMRS is greater than a bandwidth threshold, or the first DMRS includes K DMRS transmission symbols in one slot and a time interval between any two DMRS transmission symbols is greater than a time threshold; it may be guaranteed that performing QCL estimation (i.e., making QCL-assumed estimates) using the first DMRS can meet the processing time requirements of the signal carrying the first DMRS.

In one possible implementation, the first DMRS and the second signal each correspond to a first code division multiplexing, CDM, group. For example, the first DMRS and the second signal both adopt coding schemes corresponding to the first CDN group.

In this implementation, the first DMRS and the second signal both correspond to the first code division multiplexing, CDM group, which may ensure that the first DMRS and the second signal have the same large scale characteristic.

In one possible implementation, the method further includes: the terminal device receives second indication information from the network device, wherein the second indication information indicates a QCL relationship between the second signal and the first DMRS.

In this implementation, second indication information is received from the network device, so as to obtain the QCL relationship between the second signal and the first DMRS using the second indication information.

In one possible implementation, the second indication information indicates a second transmission control indication, TCI, state, the second TCI state including a QCL relationship between the second signal and the first DMRS.

In this implementation, the second indication information indicates a second TCI state with little resource overhead.

In one possible implementation manner, the second signal is a demodulation reference signal or a channel state information reference signal CSI-RS.

In one possible implementation, before receiving the second signal according to the second channel large scale parameter, the method further includes: and performing channel estimation based on the first DMRS to obtain the second channel large-scale parameter.

In one possible implementation, the second indication information indicates a QCL relationship of the second signal with a first port group identity, ID, or a first DMRS port ID of the first DMRS.

In the implementation manner, power allocations corresponding to signals sent by the network device on different DMRS ports or port groups are different, and the second indication information indicates a QCL relationship between the second signal and the first port group identity ID of the first DMRS or the first DMRS port ID, so as to more accurately estimate the large-scale parameter of the second channel.

In a fourth aspect, an embodiment of the present application provides a communication method, where the method includes: the method comprises the steps that network equipment sends a first demodulation reference signal (DMRS) to terminal equipment; sending second indication information to the terminal device, wherein the second indication information indicates a quasi co-located QCL relationship between a second signal and the first DMRS; and sending the second signal to the terminal equipment.

In the embodiment of the application, the network device sends the second indication information to the terminal device, so that the terminal device receives the second signal by using the channel large-scale parameter of the first DMES. Therefore, the terminal equipment can estimate the QCL hypothesis through the DMRS without depending on the tracking reference signal on the premise of not influencing the data receiving performance obviously.

In this implementation, the bandwidth of the first DMRS is greater than a bandwidth threshold, or the first DMRS includes K DMRS transmission symbols in one slot and a time interval between any two DMRS transmission symbols is greater than a time threshold; it may be ensured that performing QCL estimation using the first DMRS can meet the processing time requirements of the signal carrying the first DMRS.

In one possible implementation, the second indication information indicates that a second transmission control indicates a second TCI state, the second TCI state including a QCL relationship between the second signal and the first DMRS.

In the implementation manner, power allocations corresponding to signals sent by the network device on different DMRS ports or port groups are different, and the second indication information indicates a QCL relationship between the second signal and the first port group identity ID of the first DMRS or the first DMRS port ID, so that the second channel large-scale parameter is estimated more accurately.

In a fifth aspect, an embodiment of the present application provides a communication method, where the method includes: the terminal equipment receives a plurality of second demodulation reference signals (DMRS) transmitted by the network equipment, wherein the plurality of second DMRS correspond to a second DMRS port group Identity (ID) or a second DMRS port ID; receiving a third signal according to the third channel large-scale parameter; and the third channel large-scale parameter is obtained by performing time domain filtering on a plurality of channel large-scale parameters obtained by estimating the plurality of second DMRSs.

In the embodiment of the present application, the third signal is received according to the third channel large-scale parameter. The third channel large-scale parameter is obtained by performing time-domain filtering on the plurality of channel large-scale parameters obtained by estimating the plurality of second DMRSs, so that the third channel large-scale parameter is a relatively robust large-scale estimation result, and the channel state experienced by the third signal can be accurately reflected.

In one possible implementation, before receiving the third signal according to the third channel large-scale parameter, the method further includes: the terminal equipment performs channel estimation according to the plurality of second DMRSs received in a preset time window to obtain a plurality of channel large-scale parameters; and performing time domain filtering on the plurality of channel large-scale parameters to obtain the third channel large-scale parameter.

In the implementation mode, time domain filtering is carried out on a plurality of channel large-scale parameters to obtain a third channel large-scale parameter; relatively robust large-scale estimation results (i.e., channel large-scale parameters) can be obtained.

In one possible implementation, a bandwidth of each of the plurality of second DMRS is greater than a bandwidth threshold, or each of the plurality of second DMRS includes K DMRS transmission symbols in one slot and a time interval between any two DMRS transmission symbols is greater than a time threshold, K being an integer greater than 1.

In one possible implementation, the method further includes: and the terminal equipment receives third indication information from the network equipment, wherein the third indication information indicates the QCL relationship between the third signal and the second DMRS port group identity ID, or the third indication information indicates the QCL relationship between the third signal and the second DMRS port ID.

In this implementation, the terminal device receives the third indication information, and may timely obtain a QCL relationship between the third signal and the second DMRS port group ID or a QCL relationship between the third signal and the second DMRS port ID.

In one possible implementation, the third indication information indicates a third transmission control indication, TCI, state, the third TCI state including a QCL relationship between the third signal and the second DMRS port group ID, or the third TCI state including a QCL relationship between the third signal and the second DMRS port ID.

In this implementation, the third indication information indicates a third TCI state, with little resource overhead.

In one possible implementation manner, the third signal is a demodulation reference signal or a channel state information reference signal CSI-RS.

In a sixth aspect, an embodiment of the present application provides a communication method, where the method includes: the method comprises the steps that a network device transmits a plurality of second DMRS to a terminal device, wherein the plurality of second DMRS correspond to a second DMRS port group identity ID or a second DMRS port ID; transmitting third indication information to the terminal device, the third indication information indicating a QCL relationship between a third signal and the second DMRS port group identity representation ID or indicating a QCL relationship between the third signal and the second DMRS port ID; and sending the third signal to the terminal equipment.

In this embodiment, the network device sends the third indication information to the terminal device, so that the terminal device receives the third signal by using the channel large-scale parameters of the plurality of second DMESs. Therefore, the terminal equipment can estimate the QCL assumption through the DMRS without depending on the tracking reference signal on the premise of not influencing the data receiving performance obviously.

In one possible implementation, a bandwidth of each of the plurality of second DMRS is greater than a bandwidth threshold, or each of the plurality of second DMRS includes K DMRS transmission symbols in one slot and a time interval between any two DMRS transmission symbols is greater than a time threshold, where K is an integer greater than 1.

In this implementation, the bandwidth of each second DMRS is greater than a bandwidth threshold, or each second DMRS includes K DMRS transmission symbols in one slot and a time interval between any two DMRS transmission symbols is greater than a time threshold; it may be ensured that performing QCL estimation using the second DMRS may satisfy the processing time requirements of the signal carrying the second DMRS.

In a seventh aspect, an embodiment of the present application provides a terminal device, including: the receiving and sending unit is used for receiving first indication information sent by the network equipment; the first indication information indicates a plurality of reference signals having a quasi-co-located QCL relationship with a first signal and a QCL weight for each of the plurality of reference signals; the processing unit is used for obtaining a first channel large-scale parameter by using the plurality of reference signals and QCL weight processing of each reference signal in the plurality of reference signals; the transceiver unit is further configured to receive the first signal according to the first channel large-scale parameter.

In one possible implementation, the plurality of reference signals and the first signal each correspond to a first frequency band, a first transport layer, and a first data stream.

In a possible implementation manner, the transceiver unit is further configured to receive the plurality of reference signals; the processing unit is further configured to estimate a channel large-scale parameter by using the plurality of reference signals, respectively, to obtain the plurality of channel large-scale parameters; and synthesizing the plurality of channel large-scale parameters by using the QCL weight of each reference signal in the plurality of reference signals to obtain the first channel large-scale parameter.

With regard to technical effects brought about by the seventh aspect or various possible implementations, reference may be made to the introduction of the technical effects of the first aspect or the corresponding implementations.

In an eighth aspect, an embodiment of the present application provides a network device, including: a processing unit for generating first indication information indicating a plurality of reference signals having a quasi-co-located QCL relationship with a first signal and a QCL weight for each of the plurality of reference signals; the receiving and sending unit is used for sending the first indication information to the terminal equipment; the first indication information is used for the terminal equipment to receive the first signal.

In a possible implementation manner, the first signal is a demodulation reference signal DMRS or a channel state information reference signal CSI-RS, and the multiple reference signals are different tracking reference signals TRS.

With regard to the technical effects brought about by the eighth aspect or the various possible implementations, reference may be made to the introduction of the technical effects of the second aspect or the corresponding implementations.

In a ninth aspect, an embodiment of the present application provides a terminal device, including: the device comprises a transceiving unit, a receiving and sending unit and a processing unit, wherein the transceiving unit is used for receiving a first demodulation reference signal (DMRS) sent by network equipment; the processing unit is used for obtaining a second channel large-scale parameter based on the channel large-scale parameter of the first DMRS; the transceiver unit is further configured to receive a second signal according to the second channel large-scale parameter; the second signal is a reference signal having a QCL relationship with the first DMRS.

In one possible implementation, the first DMRS and the second signal each correspond to a first code division multiplexing, CDM, group.

In one possible implementation, the terminal device receives second indication information from the network device, where the second indication information indicates a QCL relationship between the second signal and the first DMRS.

In a possible implementation manner, the processing unit is further configured to estimate a channel large-scale parameter by using the first DMRS, and obtain the second channel large-scale parameter.

With regard to the technical effects brought about by the ninth aspect or various possible implementations, reference may be made to the introduction of the technical effects of the third aspect or the corresponding implementations.

In a tenth aspect, an embodiment of the present application provides a network device, including: a transceiving unit, configured to send a first demodulation reference signal DMRS to a terminal device; sending second indication information to the terminal device, wherein the second indication information indicates a quasi co-located QCL relationship between a second signal and the first DMRS; a processing unit for generating the second signal; the transceiver unit is further configured to send the second signal to the terminal device.

With regard to the technical effects brought about by the tenth aspect or various possible implementations, reference may be made to the introduction to the technical effects of the fourth aspect or the corresponding implementations.

In an eleventh aspect, an embodiment of the present application provides a terminal device, including: a transceiver unit, configured to receive a plurality of second DMRS transmitted by a network device, where the plurality of second DMRS corresponds to a second DMRS port group identity ID or a second DMRS port ID; a processing unit, configured to perform time-domain filtering on the multiple channel large-scale parameters estimated by the multiple second DMRS to obtain a third channel large-scale parameter; the transceiver unit is further configured to receive a third signal according to the third channel large-scale parameter.

In a possible implementation manner, the processing unit is further configured to perform channel estimation according to the plurality of second DMRSs received within a preset time window, so as to obtain the plurality of channel large-scale parameters.

In a possible implementation manner, the transceiver unit is further configured to receive third indication information from the network device, where the third indication information indicates a QCL relationship between the third signal and the second DMRS port group identity ID, or the third indication information indicates a QCL relationship between the third signal and the second DMRS port ID.

With regard to the technical effects brought about by the eleventh aspect or various possible implementations, reference may be made to the introduction to the technical effects of the fifth aspect or the corresponding implementations.

In a twelfth aspect, an embodiment of the present application provides a network device, including: a transceiver unit, configured to transmit a plurality of second DMRS to a terminal device, where the plurality of second DMRS corresponds to a second DMRS port group identity ID or a second DMRS port ID; transmitting third indication information to the terminal device, the third indication information indicating a QCL relationship between a third signal and the second DMRS port group identity representation ID or indicating a QCL relationship between the third signal and the second DMRS port ID; a processing unit for generating the third signal; the transceiver unit is further configured to send the third signal to the terminal device.

With regard to the technical effects brought about by the twelfth aspect or various possible implementations, reference may be made to the introduction of the technical effects of the sixth aspect or the corresponding implementations.

In a thirteenth aspect, an embodiment of the present application provides a communication apparatus, which includes a processor, configured to execute computer-executable instructions stored in a memory, so as to cause the communication apparatus to perform the method of the first aspect, the third aspect, or the fifth aspect, and any possible implementation manner.

In one possible implementation, the memory is located outside the communication device.

In one possible implementation, the memory is located within the communication device described above.

In a possible implementation, the processor and the memory may also be integrated in one device, i.e. the processor and the memory may also be integrated together.

In a possible implementation, the communication device further includes a transceiver, which is configured to receive a message or send a message, and the like.

In a fourteenth aspect, an embodiment of the present application provides a communication apparatus, which includes a processor, and the processor is configured to execute computer-executable instructions stored in a memory, so as to cause the communication apparatus to perform the method of the second aspect, the fourth aspect, or the sixth aspect, and any possible implementation manner.

In a fifteenth aspect, an embodiment of the present application provides a communication device, which includes a logic circuit and an interface, where the interface is used to obtain data or output data; the logic circuit is configured to perform a corresponding method as shown in the first aspect, the third aspect or the fifth aspect and any possible implementation manner.

In a sixteenth aspect, an embodiment of the present application provides a communication device, including a logic circuit and an interface, where the interface is used to obtain data or output data; the logic circuit is configured to perform a corresponding method as shown in the second aspect, the fourth aspect or the sixth aspect and any possible implementation.

In a seventeenth aspect, the present application provides a computer-readable storage medium for storing a computer program which, when run on a computer, causes the method illustrated in any possible implementation of the above first to sixth aspects or first to sixth aspects to be performed.

In an eighteenth aspect, the present application provides a computer program product comprising a computer program or computer code which, when run on a processor, causes the method shown in any of the possible implementations of the first to sixth aspects or the first to sixth aspects described above to be performed.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the background art of the present application, the drawings required to be used in the embodiments or the background art of the present application will be described below.

FIG. 1 is an example of a Multi-TRP scenario provided by an embodiment of the present application;

fig. 2A is a schematic diagram illustrating a manner in which a UE measures TRS under multiple TRP coordination according to an embodiment of the present application;

fig. 2B is a schematic diagram illustrating another way of measuring TRS by a UE under multiple TRP coordination according to an embodiment of the present application;

fig. 3A and fig. 3B are schematic diagrams illustrating a power delay spectrum synthesis provided by an embodiment of the present application;

fig. 4 is an example of QCL hypothesis indication provided in an embodiment of the present application;

fig. 5 is a flowchart of a downlink transmission method based on multi-station cooperation according to an embodiment of the present application;

fig. 6 is a flowchart of another downlink transmission method based on multi-station cooperation according to an embodiment of the present application;

fig. 7 is a flowchart of a communication method according to an embodiment of the present application;

fig. 8 is a flowchart of another communication method provided in the embodiments of the present application;

fig. 9 is a flowchart of another communication method provided in an embodiment of the present application;

fig. 10 is a flowchart of another communication method provided in the embodiments of the present application;

fig. 11 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 12 is a schematic structural diagram of a communication device according to an embodiment of the present application;

fig. 13 is a schematic structural diagram of another communication device according to an embodiment of the present application;

fig. 14 is a schematic structural diagram of another communication device 140 according to an embodiment of the present disclosure.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more clear, the present application will be further described with reference to the accompanying drawings.

The terms "first" and "second," and the like in the description, claims, and drawings of the present application are used solely to distinguish between different objects and not to describe a particular order. Furthermore, the terms "comprising" and "having," as well as any variations thereof, are intended to cover non-exclusive inclusions. Such as a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus. The term "plurality" means two or more. The symbol "/" denotes "or". For example, A/B represents A or B.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those skilled in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

As described in the background art, how to accurately receive a signal whose channel large scale is synthesized by two or more transmission paths transmitting reception points TRP is a subject of current research. One currently employed scheme of receiving a signal synthesized by a transmission path of two or more TRPs is as follows: estimating large-scale information (for example, large-scale information of superimposed signals of multiple TRSs) of multiple reference signals jointly (cooperatively) transmitted by two or more than two TRPs, and directly configuring the large-scale information (for example, channel large-scale parameters) to a DMRS/channel state information reference signal (CSI-RS) as a QCL hypothesis; then, the DMRS/CSI-RS is received according to the QCL hypothesis of the DMRS/CSI-RS. Accurately estimating the large-scale information of multiple reference signals jointly (cooperatively) transmitted by two or more TRPs is a key step in the above scheme. The downlink transmission method based on multi-station cooperation can accurately estimate the large-scale information of a plurality of reference signals jointly (cooperatively) sent by two or more TRPs, and further accurately receive the signals of which the channel large-scale is synthesized by the transmission paths of two or more transmission receiving points TRP. Since the present application relates to QCL assumptions and associated knowledge of channel estimation for DMRS, the associated knowledge and terminology to which the present application relates is introduced below.

QCL hypothesis

QCL of signal assumes: the large-scale characteristic of the channel experienced by the signal when the signal is transmitted by a transmitting end and experiences the channel to a receiving end is characterized. The large scale characteristics include at least: doppler shift, doppler spread, delay spread, average delay, and spatial receive parameters (spatialrx parameter).

Doppler shift (doppler shift): the doppler shift is generated due to the angle between the moving direction of the receiving end and the arrival direction of the signal. For example, the frequency of the signal is fc, and the frequency of the received signal is fc +/-fd due to the movement of the receiving end, and fd is doppler shift.

Doppler spread (doppler spread): the signal propagation experiences a scattering path, which causes the frequency band of the signal transmission to diffuse out of band at the receiving end, resulting in doppler spread.

Delay spread (delay spread): a pulse signal sent by a sending end not only contains the signal itself, but also contains signals at various time delay points in a signal received by a receiving end, which can cause the time width of the signal to expand.

Average delay (average delay): the average time delay of the signal after the signal passes through the multipath channel and reaches the receiving end.

Spatial receive parameter (spatialrx parameter): a digital weighted sum (beamforming) scheme is adopted for a transmission signal at a transmitting end, so that the transmission signal has a characteristic of directional transmission in space. The receiving end may use a beamforming scheme corresponding to the transmission beamforming to improve the performance of the received signal, where the received beamforming information is spatial reception parameter information.

Port: describing the physical resource corresponding to the signal sent by the sending end/the signal received by the receiving end. The physical resources include: time domain resources, frequency domain resources, space domain resources, code domain resources, antenna resources, and the like.

The QCL assumption for the DMRS port is indicated by configuring a QCL relationship between the DMRS port and another RS. For example, parameters related to doppler and delay can be estimated in advance through measurement on another RS, and the estimated parameters can be applied to DMRS reception on the assumption that the propagation environment of the RS and the large-scale characteristics of the channel under the propagation environment of the DMRS are not changed (that is, the channel large-scale parameters of the DMRS are substantially the same as the channel large-scale parameters of the RS). The signaling for indicating the QCL parameters, which may include one or more RS IDs, may be configured in practical applications. One possible way is as follows:

the QCL is configured in a transmission control indication state (TCI) state (state) assuming that the QCL type is to be configured. QCL types in 4 are currently defined as follows:

-'QCL-TypeA':{doppler shift,doppler spread,average delay,delay spread}

-'QCL-TypeB':{doppler shift,doppler spread}

-'QCL-TypeC':{doppler shift,average delay}

-'QCL-TypeD':{spatial Rx parameter}

for example, when the QCL TypeA relationship exists between the DMRS port and the CSI-RS port, the received doppler shift, doppler spread, average delay, and delay spread adopted by the DMRS port are obtained based on the measurement of the CSI-RS port. That is, doppler shift, doppler spread, average delay, and delay spread of the CSI-RS port may be used as doppler shift, doppler spread, average delay, and delay spread of the DMRS port.

For another example, when the DMRS port, the CSI-RS port 1, and the CSI-RS port 2 have a QCL TypeA and a QCL TypeD relationship, respectively, doppler shift, average delay, and delay used for receiving the DMRS port are obtained based on the CSI-RS port 1, and spatial Rx parameters (i.e., spatial Rx parameters) used for receiving the DMRS port are obtained based on the CSI-RS port 2. In addition, reference signals are currently specified that may be used to indicate different QCL types, such as QCL indication for DMRS:

both 'QCL-TypeA' and 'QCL-TypeD' configure the same TRS, or,

- 'QCL-TypeA' configuration TRS, 'QCL-TypeD' configuration CSI-RS, or,

QCL-TypeA 'and QCL-TypeD' both configure the same CSI-RS

As QCL indication for CSI-RS:

both 'QCL-TypeA' and 'QCL-TypeD' configure the same TRS, or,

- 'QCL-TypeA' configuration TRS, 'QCL-TypeD' configuration SS/PBCH block, or,

-QCL-TypeA ' configuration TRS, ' QCL-TypeD ' configuration CSI-RS, or,

QCL-TypeB' configuration TRS

A DMRS, which is a reference signal used for channel estimation when receiving a PDSCH/Physical Downlink Control Channel (PDCCH). The receiving end knows that the DMRS sequence can acquire a signal transmission channel through the DMRS, and if the channel is a channel experienced during PDSCH/PDCCH transmission, the channel estimation of the PDSCH/PDCCH can be completed through the DMRS. That is, the DMRS sequence transmitted by the transmitting end is known by the receiving end, and the receiving end can estimate a channel through which the DMRS has gone by using the known DMRS sequence and the received DMRS. In new radio access technology (NR), a port of DMRS (alternatively referred to as DMRS port) and a port of PDSCH/PDCCH experience the same channel. That is, the DMRS and PDSCH/PDCCH are transmitted in the same manner (transmission antenna and precoding operation). In NR, the definition of DMRS port is: each DMRS port corresponds to a specific time-frequency code resource, and the time-frequency code resources occupied by different DMRS ports are orthogonal. When the time frequency resources corresponding to a plurality of DMRS ports are the same, the plurality of DMRS ports depend on code division multiplexing, and each group of DMRS ports occupying the same time frequency resources corresponds to one Code Division Multiplexing (CDM) group.

The CSI-RS is used for measuring and reporting Channel State Information (CSI).

The TRS is configured to perform time-frequency tracking, normally occupies two consecutive slots (slots) in a time domain, occupies two Orthogonal Frequency Division Multiplexing (OFDM) symbols in each slot, and has a spacing of 3 OFDM symbols between the two OFDM symbols, so that the accuracy of estimating doppler shift and averagedelay can be improved by such a configuration. The TRS has a certain requirement on a minimum bandwidth in a frequency domain, for example, the bandwidth cannot be smaller than 10M, so as to accurately estimate the delay path information to obtain doppler spread and delay spread information. A certain number of Resource Elements (REs) are required in each Resource Block (RB) to ensure the balance between accuracy and overhead. For example, in NR, a TRS within one RB occupies 3 REs.

Indication mechanism of QCL hypothesis for measurement reference signals:

the notification method of QCL assumption is: a network device (e.g., a base station) indicates the TCIstate used by the currently scheduled PDSCH through Downlink Control Information (DCI). For example, a TCI indication field including 3-bit in DCI is used to indicate TCI state, see table 1.

TABLE 1

State value of TCI indication field	Corresponding meaning
		000	TCI state 1
001	TCI state 2
		…	…
111	TCI state 7

Each TCI state includes a QCL relationship (QCL relationship) between a DMRS port (referred to as target RS) and one or more reference signal ports (referred to as reference RS). Based on this QCL relationship, the QCL hypothesis determination procedure for the DMRS port may be as follows: the network equipment issues one or more reference signal ports (reference RSs) in advance; the UE determines QCL hypothesis information through one or more reference signal ports; and the UE receives a DMRS port (target RS) through the determined QCL hypothesis information.

The following describes a scenario in which the downlink transmission method based on multi-station cooperation provided by the present application is applicable. The downlink transmission method based on multi-station cooperation is suitable for a downlink transmission scene of multi-station cooperation transmission. The downlink transmission method based on multi-station cooperation is suitable for both homogeneous network scenes and heterogeneous network scenes. Meanwhile, there is no limitation on the transmission receiving point, and the transmission receiving point may be multi-point cooperative transmission between the macro base station and the macro base station, between the micro base station and the micro base station, and between the macro base station and the micro base station, and is applicable to both Frequency Division Duplexing (FDD)/Time Division Duplexing (TDD) systems. The downlink transmission method based on the multi-station cooperation is suitable for a low-frequency scene (sub 6G) and is also suitable for a high-frequency scene (more than 6G). The downlink transmission method based on the multi-station cooperation is suitable for a 4G,5G or future mobile communication system. The downlink transmission method based on the Multi-station cooperation is suitable for a plurality of panels or Multi-TRP scenes under Single-TRP and any derivative scene of the panels or the Multi-TRP scenes.

Fig. 1 is an example of a Multi-TRP scenario provided in an embodiment of the present application. As shown in fig. 1, a Multi-TRP scenario includes: two or more network devices (only two shown in fig. 1), one or more UEs (only one shown in fig. 1). In a Multi-TRP scene, two or more network devices complete data scheduling and transmission for the same UE in a cooperative scheduling mode. As shown in fig. 1, serving cells of the UE are TRP1 and TRP2, TRP1 and TRP2 configure TRS resources for the UE, TRP1 and TRP2 transmit TRS simultaneously (i.e. TRP1 transmits TRS1, TRP2 transmits TRS 2), and the UE can directly estimate channel large scale information on its own TRS resources. In fig. 1, the channel experienced by the TRS1 for TRP1 transmission and the channel experienced by the PDSCH1 for its transmission are substantially unchanged, and the channel experienced by the TRS2 for TRP2 transmission and the channel experienced by the PDSCH2 for its transmission are substantially unchanged. It should be understood that it may be assumed that the large-scale characteristics of the channel under the propagation environment of the TRS1 and the propagation environment of the PDSCH1 are not changed, and the large-scale characteristics of the channel under the propagation environment of the TRS2 and the propagation environment of the PDSCH2 are not changed. In this way, the TRS received by the UE is actually a signal superposition of TRSs jointly transmitted by a plurality of TRPs (e.g., TRP1 and TRP 2).

In coherent transmission of a Multi-TRP scene, each data stream and a corresponding DMRS port are issued by a plurality of cooperative base stations with multiple antennas in a coherent transmission mode. Specifically, a transmission precoding matrix (including inter-antenna amplitude and phase information) of each cooperative base station in the multiple cooperative base stations is determined not only based on a channel from the UE to the station, but also based on channels from the UE to other cooperative stations, so that signals transmitted by the multiple cooperative stations to the UE end are coherently superposed as much as possible, thereby improving transmission performance. In one mode, the precoding matrix of the cooperative base station is obtained by Singular Value Decomposition (SVD) decomposition of a composite channel formed by splicing the channels of each base station in the antenna dimension. One scheme for the UE to estimate the large scale information of the TRS jointly transmitted by multiple TRPs is as follows: configuring a TRS for each TRP (such as a base station), and respectively estimating the TRS of each TRP by the UE to obtain a plurality of estimated values (namely channel large-scale parameters); determining a composite estimate based on the plurality of estimates; channel estimation of DMRS is made based on the synthesized estimate as a QCL hypothesis.

Optionally, the QCL hypothesis indicated by each TRS is of the same type. Aiming at the same QCL hypothesis type, the UE respectively estimates the TRS of each TRP to obtain a plurality of estimation values (namely channel large-scale parameters); determining a composite estimate based on the plurality of estimates; channel estimation of DMRS is made based on the synthesized estimate as a QCL hypothesis.

Since the TRS resources (i.e., physical resources of the TRS) are cell-level, that is, each cell can be configured with a specific TRS resource, UEs in the cell can measure the TRS configured in the cell. The TRSs of neighboring cells occupy orthogonal resources as much as possible to avoid strong interference with each other, but the cells with less interference may be configured with the same TRS resources. At this time, different cells use different scrambling codes, so that the correlation of the TRS signals among different cells is reduced to reduce the cell interference received by the receiving end.

On the basis, for a certain UE cooperatively served by a plurality of TRPs, the TRS resource corresponding to each cooperative TRP may be allocated to the UE. And the UE respectively estimates the channel large-scale parameters based on all TRS resources and performs time domain filtering. Fig. 2A is a schematic diagram of a manner in which a UE measures a TRS under multiple TRP coordination according to an embodiment of the present application. As shown in fig. 2A, the cooperative cell of the UE is 2 TRPs, two TRPs issue TRS1 and TRS2 respectively, the two TRSs may occupy orthogonal resources, the UE acquires two sets of channel large scale parameters according to TRS1 and TRS2 respectively, and the estimation result is accurate for a single station (i.e., a single TRP). In fig. 2A, the channel experienced by the TRS1 for TRP1 transmission and the channel experienced by the PDSCH1 for its transmission are substantially unchanged, and the channel experienced by the TRS2 for TRP2 transmission and the channel experienced by the PDSCH2 for its transmission are substantially unchanged. In fig. 2A (case one), the received power (P) of TRS1 _TRS1 ) And the received power (P) of TRS2 _TRS2 ) The ratio of the received power is 1:2, the ratio of the received power represents the conditions of the path loss from TRP1 and TRP2 to the UE and the transmission power from TRS, the UE can directly determine the RSRP value of TRS according to the TRS measurement so as to acquire the information, and the base station can report the information according to the measurement of the UE or acquire the information through the measurement of uplink signals by utilizing the uplink-downlink mutual anisotropy; transmission power P of one PDSCH/DMRS port is transmitted by TRP1 and TRP2 at the same time _PDSCH1 And P _PDSCH2 Is 1:1. Fig. 2B is a schematic diagram of another method for a UE to measure a TRS under multi-TRP cooperation according to an embodiment of the present application. In another example of FIG. 2A, the transmit power (P ') of TRS 1' _TRS1 ) And TRS2 transmission power (P' _TRS2 ) Is 1, TRP1 and TRP2 simultaneously transmit the transmission power P 'of one PDSCH/DMRS port' _PDSCH1 And P' _PDSCH2 Is 1:2. In the subsequent PDSCH transmission, if the two TRPs will transmit the same data stream at the same time, the data stream experiences a channel overlapping the two TRPs to the UE from the UE reception perspective. For example, the base station at this timeThe QCL, which would indicate the DMRS for this PDSCH, assumes TypeA to be TRS1+ TRS2, indicating that the channel large scale experienced by the DMRS is synthesized by two TRP transmission paths. After receiving the QCL hypothesis indication information, the UE estimates a synthesized channel large-scale parameter (i.e., a channel large-scale parameter synthesized from the channel large-scale parameter obtained by estimating the TRS1 and the channel large-scale parameter obtained by estimating the TRS 2) based on the TRS1 and the TRS2, and receives the DMRS using the synthesized channel large-scale parameter.

However, the synthesized QCL parameters (i.e. synthesized channel large-scale parameters) estimated by the UE based on TRS1 and TRS2 cannot be directly used for the subsequent PDSCH/DMRS/CSI-RS jointly transmitted by TRP1 and TRP 2. For example, the UE may obtain one power delay spectrum according to the TRS1 and the TRS2, estimate a delay spread according to the two power delay spectrums, and generate a wiener filter coefficient according to the delay spread. The wiener filter coefficients can be used for channel estimation based on DMRS/CSI-RS, and the UE obtains the channel on the non-pilot RE through the channel on the RE occupied by the pilot based on the difference value of the wiener filter. For DMRS, the UE may further receive PDSCH by obtaining channel estimation results (i.e., channel large-scale parameters of DMRS). For CSI-RS, the UE may feedback CSI by obtaining a channel estimation result (i.e., a channel large-scale parameter of DMRS). However, the UE cannot directly reflect the power distribution of each tap (spatial transmission path) in the delay domain actually received by the DMRS/CSI-RS in the delay domain, in the power distribution of each tap in the delay domain received by the TRS1 and TRS 2. This is because when the TRP terminal(s) actually issues the DMRS/CSI-RS, the TRP terminal performs joint precoding and also performs inter-stream (corresponding to a data stream or a modulation and coding scheme)/inter-transport layer/inter-RB (corresponding to a frequency band) power allocation, and the UE does not consider the case where the TRP terminal performs inter-stream/inter-transport layer/inter-RB (corresponding to a frequency band) power allocation but defaults to have the same inter-stream/inter-transport layer/inter-RB power. For example, after obtaining the power delay spectrum of the TRS1 and the power delay spectrum of the TRS2, the UE directly synthesizes the power delay spectrum of the TRS1 and the power delay spectrum of the TRS2 (i.e., directly superimposes the power delay spectrum of the RS1 and the power delay spectrum of the TRS 2), and uses the synthesized power delay spectrum as the power delay spectrum of the subsequent PDSCH/DMRS/CSI-RS. It should be understood that the power delay spectrum obtained by the UE based on the TRS1 and TRS2 does not accurately reflect the channel state experienced by the subsequent PDSCH/DMRS/CSI-RS, and therefore, the UE cannot accurately estimate the channel on the DMRS/CSI-RS based on the determined QCL assumption.

Fig. 3A and fig. 3B are schematic diagrams illustrating power time-delay spectrum synthesis provided in the embodiment of the present application. Fig. 3A shows a power delay profile of the TRS1 (transmitted by the TRP 1), a power delay profile of the TRS2 (transmitted by the TRP 2), and a power delay profile synthesized by the power delay profiles of the TRS1 and TRS2 obtained by the UE. Fig. 3B shows the power delay spectrum of the DMRS transmitted by the TRP1, the power delay spectrum of the DMRS transmitted by the TRP2, and a power delay spectrum synthesized by the power delay spectrum of the DMRS transmitted by the TRP1 and the power delay spectrum of the DMRS transmitted by the TRP2, which are obtained by the UE. In fig. 3A, TRS1 and TRS2 are TRS1 and TRS2 in fig. 2A, and the power ratio of TRS1 and TRS2 is 1:2 (i.e., the received power of TRS 1: the received power of TRS 2). In fig. 3B, DMRS for TRP1 transmission is carried on signal 1 for TRP1 transmission by PDSCH in fig. 2A, DMRS for TRP2 transmission is carried on signal 2 for TRP2 transmission by PDSCH in fig. 2A, and the power ratio of signal 1 for TRP1 transmission by PDSCH and signal 2 for TRP2 transmission by PDSCH is 1:1 (power of signal 1: power of signal 2). The channel state experienced by the DMRS transmitted by the TRP1 in fig. 3B may be regarded as the same as the channel state experienced by the TRS1 in fig. 3A, and the channel state experienced by the DMRS transmitted by the TRP2 in fig. 3B may be regarded as the same as the channel state experienced by the TRS2 in fig. 3A. Since the power ratio of the signal 1 transmitted by the PDSCH of the TRP1 to the signal 2 transmitted by the PDSCH of the TRP2 is different from the power ratio of the TRS1 to the TRS2, the power delay spectrum synthesized by the power delay spectrum of the TRS1 and the power delay spectrum of the TRS2 and the power delay spectrum synthesized by the power delay spectrum of the DMRS transmitted by the TRP1 and the power delay spectrum of the TRP2 are different from each other. Similarly, when the power proportion of each TRS (or CSI-RS) is not considered, the channel large-scale parameter obtained by the UE based on each TRS (e.g., TRS1 and TRS 2) (i.e., the channel large-scale parameter synthesized based on the channel large-scale parameters of each TRS) is greatly different from the channel large-scale parameters of the multiple DMRSs. That is, the power allocation of the DMRS affects the matching degree of the channel large-scale parameter synthesized based on the channel large-scale parameters of multiple TRSs (or CSI-RSs) and the channel large-scale parameter actually issued by the network device, thereby causing performance degradation. In addition, the power allocation when the network device (base station) transmits the DMRS is completely transparent to the UE (i.e., the UE does not know the power allocation of the DMRS), and the UE cannot acquire synthesized channel characteristics (corresponding to channel large-scale parameters) based on multiple TRSs/CSI-RSs according to the power allocation when the network device (base station) transmits the DMRS.

In order to accurately estimate large-scale information of a plurality of reference signals jointly (cooperatively) transmitted by two or more TRPs, the application provides a downlink transmission method based on multi-station cooperation. This method can be considered as a method of accurately indicating QCL assumptions. The main principle of the method is as follows: the QCL of a network device (such as a base station) for configuring a specific DMRS port (or CSI-RS port) is assumed to be a plurality of TRS/CSI-RSs, and QCL weights among the plurality of TRS/CSI-RSs are configured. The QCL weights between the plurality of TRS/CSI-RSs are used to instruct the UE how to acquire the synthesized channel characteristics based on the plurality of TRS/CSI-RSs.

QCL weights are used to characterize: and when the synthesis QCL hypothesis is generated, taking the ratio of the values of QCL hypothesis parameters generated by the TRS/CSI-RS in the synthesis QCL hypothesis. For example, for the Delay spread in the QCL hypothesis, the Delay spread determined by TRS1 is X1 and the QCL weight is D1, and the Delay spread determined by TRS2 is X2 and the QCL weight is D2, then the Delay spread in the synthesized QCL hypothesis takes on the value of X1 × D1+ X2 × D2. Or, when the synthesized QCL hypothesis is generated, determining the PDP (i.e., the synthesized PDP) of the synthesized QCL hypothesis according to the ratio of the power-Delay profile (PDP) generated by each TRS/CSI-RS in the synthesized PDP, and further determining the synthesized Delay spread according to the synthesized PDP. For example, the quantized PDP determined from TRS1 is [ a1, …, ak, … an ], where k =1, … n is a DFT point, a1, …, an is a power value at each DFT point, and the QCL weight is D1, the quantized PDP determined from TRS2 is [ b1, …, bk, … bn ], and the QCL weight is D2, the PDP assumed by the synthetic QCL is [ D1 xa 1+ D2 xx b1, …, D1 xx an + D2 x bn ]. Taking fig. 2A as an example, the weight D1=1 of QCL type 1 corresponding to TRS1, and the weight D2=2 of QCL type 1 corresponding to TRSs 2, then the PDP spectral power determined based on TRS2 needs to be doubled in the process of synthesizing QCLs.

Further, QCL weights may be understood as absolute power weights of the respective TRS/CSI-RS signals when the UE generates the synthesized QCL weights from the respective TRS/CSI-RS signals. Specifically, the QCL weight of TRS1 is configured to be 0dB, and the QCL weight of TRS2 is configured to be-3 dB, so that the UE directly assumes that the QCL weight corresponding to TRS1 is 3dB greater than the QCL weight of TRS2 when synthesizing the QCL weights. Taking fig. 2A as an example, the weight D1=0dB for QCL type 1 corresponding to TRS1, and the weight D2=3dB for QCL type 1 corresponding to TRS2, then 3dB of improvement is required for the PDP spectral power determined based on TRS2 in the process of synthesizing QCLs.

QCL weights may also be understood as the power weight increase of each TRS/CSI-RS signal when the UE generates the composite QCL weights from each TRS/CSI-RS signal. Specifically, the QCL weight of TRS1 is configured to be 0dB, and the QCL weight of TRS2 is configured to be-3 dB, when the QCL weights are synthesized, the UE determines the RSRP of the received power of TRS1 and TRS2, and then determines the QCL weights of TRS1 and TRS2 according to the RSRP and the QCL weights, and the UE assumes that the QCL weight corresponding to TRS1 is the RSRP of TRS1, and the QCL weight of TRS2 is 3dB less than the RSRP of TRS 2.

One possible way to configure QCL weights is as follows:

one of the RSs is preset as a reference RS, and it can be exemplarily understood that the RS corresponds to a QCL weight of 1/K, where K is the number of the RSs. Each of the other RSs corresponds to a QCL weight indication, which may be in the form of a percentage or a dB value. The value indicated by each QCL weight characterizes the QCL weight of the corresponding RS relative to the reference RS. For example, the QCL weight value is configured to be L dB, characterizing 10log (m/n) = L, where m is the QCL weight of the respective RS and n is the QCL weight of the reference RS.

Alternatively, the value of QCL weight configuration is only negative. The reason is that the reference RS set in the scheme may be an RS corresponding to a main serving cell of the UE, and usually in a multi-TRP jointly transmitted signal, a power occupation ratio of a signal of the main serving cell is the highest, and other RSs correspond to a cooperative cell of the UE, and usually the power occupation ratio is smaller than that of the main serving cell. The QCL weight of the primary serving cell should therefore be highest for this jointly transmitted signal, which may save the signalling overhead of configuring the QCL hypothesis.

Optionally, when synthesizing a large-scale parameter of a channel, combining operation is performed on power information (without normalization) carried by a delay tap estimated on each RS. During the combining operation, the amplitude value of the delay tap on each RS is determined according to the QCL weight configuration. Specifically, for example, the amplitude value of a certain time delay tap estimated on one RS is X, and the QCL weight obtained according to QCL weight configuration is m, so that the amplitude value of the time delay tap in the synthesized PDP is m × X.

Another possible way to configure QCL weights is as follows:

and directly configuring the QCL weight corresponding to each RS in the multiple RSs, wherein the QCL weight corresponding to each RS can be a percentage or a dB value. For example, QCL weights may take the values: -3dB, -6dB, -9dB,0dB,3dB,6dB,9dB and the like. And combining the PDP spectrum estimated on each RS in the multiple RSs according to the value of the QCL weight corresponding to each RS in the multiple RSs to obtain a synthesized PDP spectrum. Specifically, in synthesizing the PDP spectrum, the power dBm value of the PDP spectrum acquired at each RS is subtracted by the QCL weight value, and then the synthesis is performed.

In some embodiments, QCL weights may be configured in the TCI state. RS IDs under a certain QCL type can be configured in one TCI state, for example, QCL type a corresponds to multiple RS IDs, and each RS ID further corresponds to one QCL weight.

Further, considering that there may be a large difference in power allocation of the TRP transmission PDSCH in each frequency band in the cooperative scheduling, the QCL weight may be indicated independently for each frequency band. The granularity of the frequency bands may be: PRG or PRG group. The scheduling strategy described above may result in a relatively small power allocation on certain frequency bands for a certain TRP, the effect of which TRP is negligible when the UE determines the large scale characteristics on that frequency band. In the embodiment of the present application, RS IDs of QCL hypotheses may be independently indicated on each frequency band.

Still further, considering that there may be a large difference in power allocation of each TRP transmission PDSCH in each transport layer in cooperative scheduling, the QCL weight may also be indicated independently for each transport layer. The above scheduling strategy may result in a relatively small power allocation on certain transport layers for a certain TRP, whose impact is negligible when the UE determines large scale characteristics on these transport layers. In the embodiment of the present application, RS IDs of QCL hypotheses may be independently indicated on each transport layer. Fig. 4 is an example of a QCL hypothesis indication provided in an embodiment of the present application. As shown in fig. 4, the UE simultaneously estimates TRS of three TRPs (i.e., TRP1, TRP2, and TRP 3) within the cooperation set, which are simultaneously used for transmitting PDSCH. Assuming that the number of transmission layers of the PDSCH is 2, as shown in the right side of fig. 4, in the QCL hypothesis indication, an RS ID may be independently indicated for each PRG and/or transmission layer, so as to characterize the large-scale characteristics of the channel on the PRG and/or transmission layer.

Still further, for PDSCH transmissions, there may be multiple codewords (codewords). One codeword corresponds to one Modulation Coding Scheme (MCS). Different codewords may correspond to different MCSs and different codewords may correspond to different transmission layers. The codewords are used to characterize the granularity of the channel coding. In the embodiment of the present application, it is also possible that each codeword (i.e. data stream) independently indicates the QCL assumption, which is to consider that the MCS difference of different codewords mainly results from the inter-stream power allocation of the TRP.

Still further, it is considered that the transmission paths experienced by the UE to the respective cooperative TRPs may have large differences. Some TRPs with rich scattering conditions or TRPs with a long physical distance may have a long delay to the channel of the UE, and this delay caused by the transmission path may be referred to as an air interface delay. The large air interface delay may cause severe frequency selective fading of the transmission signal, and even the possibility of exceeding a Cyclic Prefix (CP) may seriously affect the transmission performance of the signal. Therefore, the network device side can know air interface time delay in advance through some measurement reporting mechanisms, and perform pre-delay compensation during subsequent downlink transmission, so that the signal actually received by the UE becomes flatter in the frequency domain. This delay compensation operation may affect the large scale characteristics of PDSCH transmission and is transparent to the UE, i.e., the UE cannot obtain the delay compensated information from the TRS estimation. Thus, in the multiple TRSs indicated in the embodiment of the present application, there may be a partial TRS indicating QCL type a (uncompensated) and a partial TRS indicating QCL type B (after compensation, the TRS does not provide the delay domain channel characteristic indication).

The following describes a downlink transmission method based on multi-station cooperation with reference to the accompanying drawings. Fig. 5 is a flowchart of a downlink transmission method based on multi-station cooperation according to an embodiment of the present application. As shown in fig. 5, the method includes:

501. the terminal equipment receives first indication information sent by the network equipment.

The above-mentioned first indication information (i.e., QCL hypothesis indication) indicates a plurality of reference signals having a QCL relationship with the first signal, and a QCL weight for each of the plurality of reference signals. In this application, the terminal device refers to a UE. The transmission path of the first signal may be considered to be synthesized by the transmission paths of the plurality of reference signals. In some embodiments, the first signal comprises a plurality of reference signals, for example comprising a plurality of DMRSs or CSI-RSs. The first signal includes a plurality of reference signals (or data signals) in one-to-one correspondence with a plurality of reference signals having a QCL relationship with the first signal. The first indication information may be DCI or other downlink control information. The network device may be any one of a plurality of TRPs that jointly transmit signals to the terminal device. For example, the network device is a network device corresponding to a main serving cell accessed by the terminal device.

The transmission power of a plurality of signals comprised by the first signal, and the transmission power of a plurality of reference signals having a QCL relationship with the first signal are known to the network device. That is, the network device knows the transmission power of a plurality of signals included in the first signal and the transmission power of a plurality of reference signals having a QCL relationship with the first signal. In some embodiments, the network device may determine a QCL weight for each of a plurality of reference signals having a QCL relationship with the first signal based on the transmit power of the plurality of signals comprised by the first signal and the transmit power of the plurality of reference signals having the QCL relationship with the first signal. The network device may determine the QCL weight for each of a plurality of reference signals having a QCL relationship with the first signal in any manner, which is not limited in this application.

In a possible implementation manner, the first signal is carried on one DMRS port, or the first signal is carried on one PDSCH port, or the first signal is carried on one PDCCH port. The multiple reference signals are used as QCL hypothesis indications of the first signals loaded on the same DMRS port, PDSCH port or PDCCH port. Therefore, the UE synthesizes the large-scale parameters estimated by the multiple reference signals to obtain the channel large-scale parameters of the first signal.

In one possible implementation, the plurality of reference signals and the first signal each correspond to a first frequency band and a first transmission layer; or, the plurality of reference signals and the first signal each correspond to a first frequency band and a first data stream; alternatively, the plurality of reference signals and the first signal may correspond to a first transport layer and a first data stream. The first indication information corresponds to the first frequency band and the first transmission layer, for example, the first indication information includes an identifier of the first frequency band and an identifier of the first transmission layer. Alternatively, the first indication information corresponds to the first frequency band and the first data stream, for example, the first indication information includes an identifier of the first frequency band and an identifier of the first data stream. Alternatively, the first indication information corresponds to the first transport layer and the first data stream, for example, the first indication information includes an identifier of the first transport layer and an identifier of the first data stream. The QCL hypothesis indication (e.g., the first indication information) may indicate, in combination of any two of the frequency band, the transport layer, and the data stream, an RS ID for characterizing a large-scale characteristic of a channel on the combination of the any two. In this implementation, the plurality of reference signals and the first signal correspond not only to the same frequency band but also to the same transmission layer or data stream. The channel large-scale parameter obtained based on the multiple reference signals can better reflect the channel state experienced by the first signal.

In one possible implementation, the bandwidth occupied by the first signal includes a plurality of second frequency bands, and the QCL relationship between the first signal and the plurality of reference signals includes a QCL relationship between each second frequency band and at least one of the plurality of reference signals. In this implementation, the QCL relationship between the first signal and the plurality of reference signals includes a QCL relationship between each second frequency band and at least one of the plurality of reference signals. The channel large-scale parameter of each second frequency band can be more accurately estimated according to the QCL relationship between each second frequency band and the reference signal. It should be understood that the terminal device may estimate the channel large-scale parameter of the signal occupying the second frequency band according to the QCL relationship between the signal occupying the same second frequency band among the plurality of signals included in the first signal and the reference signal. That is, the first signal may correspond to one channel large-scale parameter at each second frequency band.

In one possible implementation, the first indication information indicates a plurality of reference signals having a QCL relationship with the first signal, and the QCL weight of each of the plurality of reference signals includes: the first indication information indicates a plurality of first Transmission Control Indication (TCI) states, the plurality of first TCI states correspond to the plurality of reference signals one to one, and each of the first TCI states further includes QCL weights of the reference signals corresponding to the first TCI states. In this implementation, the first indication information indicates the first TCI state with little resource overhead.

In one possible implementation, the first indication information includes a plurality of identifiers and a plurality of QCL weights, the identifiers are identifiers of the reference signals, the identifiers have one-to-one correspondence with the QCL weights, and the QCL weights represent ratios of values of QCL hypothesis parameters generated by the reference signals to values of QCL hypothesis parameters when the QCL hypothesis is synthesized. In this implementation, the plurality of identities and the plurality of QCL weights included in the first indication information may accurately characterize a ratio of values of QCL hypothesis parameters generated from the plurality of reference signals to values of QCL hypothesis when synthesizing the QCL hypothesis.

502. And the terminal equipment receives the first signal according to the first channel large-scale parameter.

The first channel large-scale parameter is obtained using the plurality of reference signals and QCL weights for each of the plurality of reference signals. The first signal is from a network device.

In a possible implementation manner, before performing step 502, the terminal device may perform the following operations: receiving the plurality of reference signals; estimating channel large-scale parameters by using the plurality of reference signals respectively to obtain the plurality of channel large-scale parameters; and synthesizing the plurality of channel large-scale parameters by using the QCL weight of each reference signal in the plurality of reference signals to obtain the first channel large-scale parameter.

In a possible implementation manner, the first signal is a demodulation reference signal DMRS or a channel state information reference signal CSI-RS, and the plurality of reference signals are different tracking reference signals TRS.

In some embodiments, the terminal device performs channel estimation on each reference signal received by the terminal device to obtain a channel large-scale parameter of each reference signal; after receiving the first indication information, parsing the first indication information to learn a plurality of reference signals having a QCL relationship with the first signal and a QCL weight of each of the plurality of reference signals; synthesizing a plurality of channel large-scale parameters estimated from the plurality of reference signals by using the QCL weight of each of the plurality of reference signals to obtain first channel large-scale parameters (QCL hypothesis information corresponding to the first signal); a first signal is received according to a first channel large-scale parameter.

In some embodiments, the plurality of reference signals and the first signal each correspond to a first frequency band and a first transmission layer, and the first indication information includes an identification of the first transmission layer and an identification of the first frequency band; the terminal equipment carries out channel estimation on each reference signal received by the terminal equipment to obtain a channel large-scale parameter of each reference signal; after receiving the first indication information, parsing the first indication information to learn a plurality of reference signals (corresponding to a first transport layer) having a QCL relationship with a first signal (corresponding to the first transport layer), and QCL weights for each of the plurality of reference signals; synthesizing a plurality of channel large-scale parameters estimated from the plurality of reference signals by using the QCL weight of each of the plurality of reference signals to obtain a first channel large-scale parameter (QCL hypothesis information corresponding to the first signal); a first signal is received according to a first channel large-scale parameter. For example, the network device transmits, to the terminal device, indication information 1 indicating a plurality of reference signals (to be transmitted through the transport layer 1) having a QCL relationship with a signal 3 (to be transmitted through the transport layer 1) and a QCL weight of each of the plurality of reference signals; the network device transmits, to the terminal device, indication information 2 indicating a plurality of reference signals (to be transmitted through the transport layer 2) having a QCL relationship with a signal 4 (to be transmitted through the transport layer 2) and a QCL weight of each of the plurality of reference signals. It should be appreciated that in these embodiments, the network device may independently indicate the RS ID of the QCL hypothesis for the first signal on each transport layer. Likewise, the network device may independently indicate the RS ID of the QCL hypothesis for the first signal over the frequency band (or code sub).

In some embodiments, after receiving the first indication information, the terminal device may perform channel estimation on a plurality of reference signals having QCL relationships with the first signal to obtain a channel large-scale parameter of each reference signal; synthesizing a plurality of channel large-scale parameters estimated from the plurality of reference signals by using the QCL weight of each of the plurality of reference signals to obtain first channel large-scale parameters (QCL hypothesis information corresponding to the first signal); a first signal is received according to a first channel large-scale parameter.

In the embodiment of the application, the first signal is received according to the first channel large-scale parameter. The first channel large-scale parameter is obtained by synthesizing the plurality of channel large-scale parameters estimated by the plurality of reference signals by using the QCL weight of each reference signal in the plurality of reference signals, so that the first channel large-scale parameter can more accurately reflect the channel state experienced by a subsequent first signal, and the first signal is more accurately received.

Fig. 5 mainly describes, from the terminal device side, a downlink transmission method based on multi-station cooperation provided in the present application. The downlink transmission method based on multi-station cooperation provided by the present application is described below from a network device side. Fig. 6 is a flowchart of another downlink transmission method based on multi-station cooperation according to an embodiment of the present application. As shown in fig. 6, the method includes:

601. the network device generates first indication information.

The first indication information indicates a plurality of reference signals having a quasi-co-located QCL relationship with the first signal, and a QCL weight for each of the plurality of reference signals. In some embodiments, the first signal comprises a plurality of reference signals, for example comprising a plurality of DMRSs or CSI-RSs. In some embodiments, the first signal includes a plurality of reference signals (or data signals) and a plurality of reference signals having a QCL relationship with the first signal in a one-to-one correspondence.

In some embodiments, the network device may determine QCL weights for each of a plurality of reference signals having a QCL relationship with the first signal according to transmission powers of the plurality of signals included in the first signal and transmission powers of the plurality of reference signals having the QCL relationship with the first signal, thereby generating the first indication information.

602. The network equipment sends the first indication information to the terminal equipment.

The first indication information is used for the terminal equipment to receive the first signal.

In a possible implementation manner, the first signal is carried on one DMRS port, or the first signal is carried on one PDSCH port, or the first signal is carried on one PDCCH port. In this implementation, the first signal is carried on one DMRS port, PDSCH port, or PDCCH port. The multiple reference signals are QCL hypothesis indications of a first signal carried on the same DMRS port, PDSCH port or PDCCH port. Therefore, the UE synthesizes the large-scale parameters estimated by the multiple reference signals to obtain the channel large-scale parameter of the first signal.

In one possible implementation, the plurality of reference signals and the first signal each correspond to a first frequency band and a first transmission layer; or, the plurality of reference signals and the first signal each correspond to a first frequency band and a first data stream; alternatively, the plurality of reference signals and the first signal may correspond to a first transport layer and a first data stream. The first indication information corresponds to the first frequency band and the first transmission layer, for example, the first indication information includes an identifier of the first frequency band and an identifier of the first transmission layer. Alternatively, the first indication information corresponds to the first frequency band and the first data stream, for example, the first indication information includes an identifier of the first frequency band and an identifier of the first data stream. Alternatively, the first indication information corresponds to the first transport layer and the first data stream, for example, the first indication information includes an identifier of the first transport layer and an identifier of the first data stream. The QCL hypothesis indication (e.g., the first indication information) may indicate, in combination of any two of the frequency band, the transport layer, and the data stream, an RS ID for characterizing a large-scale characteristic of a channel on the combination of the any two.

The foregoing describes a scheme of indicating QCL weights for each of a plurality of reference signals through a QCL hypothesis indication (i.e., first indication information). The UE can improve the accuracy of channel estimation according to the QCL weight of each of the plurality of reference signals. The scheme for determining QCL hypothesis information through DMRS provided in the present application is described below. By adopting the scheme for determining the QCL hypothesis information through the DMRS, the UE can estimate the QCL hypothesis through the DMRS without depending on TRS on the premise of not influencing the data receiving performance obviously, and signaling overhead is reduced.

Currently, UE makes estimation of QCL hypothesis through non-DMRS (i.e. determines information of QCL hypothesis through non-DMRS), and the present application provides a scheme for determining information of QCL hypothesis through DMRS. In the scheme for determining the QCL hypothesis information through the DMRSs, a DMRS port is included in a QCL indicator (reference RS type configured in TCI) of the DMRSs. For example, a port having a QCL type a relationship with a DMRS port or CSI-RS port may be a certain CDM group of DMRS port/DMRS port number/DMRS. Illustratively, the DMRS of the PDSCH or the doppler and delay related channel large-scale parameters of the CSI-RS may be indicated by the DMRS port. Compared with the method that the QCL hypothesis is indicated by adopting the TRS/CSI-RS, the estimation accuracy of the large-scale parameters of the channel can be improved by adopting the QCL hypothesis indicated by the DMRS. The reason is that the TRS is usually an RS transmitted at a cell level, and the network device does not transmit a directional beam in a beamforming manner when transmitting so that as many UEs in the cell as possible can receive the TRS. However, the DMRS may be directed to a specific UE by using a directional beam, so as to improve the signal-to-noise ratio of the signal and improve the estimation accuracy, and in this way, the DMRS may naturally support the network device side to perform time delay domain pre-compensation and is completely transparent to the UE. The DMRS may be a DMRS of a PDSCH, or a DMRS of a PDCCH. In addition, for a UE located at the cell edge, it is possible that the network dynamically performs cell switching on the UE (preferentially selects the serving cell of the UE according to signal quality), for example, at time n the UE is served by TRP1, and at time n +1 the UE is served by TRP2, if the UE performs QCL estimation based on TRS, the UE needs to simultaneously track two TRSs (TRP 1 and TRP 2), and requires a higher ratio for the UE, and if the UE performs QCL estimation based on DMRS, the UE may not need to track two TRSs.

Estimating QCL hypothesis information based on DMRS requires additional processing time compared to making channel estimates based on DMRS alone. At present, if the UE performs channel estimation only according to the DMRS, the operation flow is as follows: receiving signals of DMRS pilot point positions; performing least-squares (LS) channel estimation on the signal of the pilot point according to the known DMRS sequence to obtain a channel of the pilot point; the channels on the rest of the REs except the pilot bits are derived according to an interpolation algorithm (at this time, the interpolation is performed using the known QCL hypothesis information). In the embodiment of the application, before performing channel estimation based on the DMRS, the UE needs to estimate QCL hypothesis information, and the estimation of the QCL hypothesis information needs to collect signals of more DMRS pilot point locations. For example, the UE may perform channel estimation according to the DMRS only according to the pilot point position signal located on the first OFDM symbol position in the PDSCH channel time domain, but to estimate the QCL hypothesis information, the QCL estimation may be completed according to the DMRS signals located on the first OFDM symbol in the PDSCH signal time domain and the pilot point position on the OFDM symbol located at the tail of the PDSCH time domain. It can be seen that whether the UE performs QCL estimation affects the execution speed of UE channel estimation, that is, the processing speed of PDSCH reception. Therefore, in the embodiment of the present application, the characteristics of the DMRS for performing QCL estimation need to be specified, so as to determine which PDSCHs correspond to shorter processing time (corresponding to channel estimation based on the DMRS only) and which PDSCHs correspond to longer processing time (corresponding to QCL estimation and channel estimation based on the DMRS).

Based on the above considerations, the effective DMRS is defined in the present application, and the UE estimates QCL information only according to the effective DMRS. For PDSCH (or PDCCH), the effective DMRS thereof needs to satisfy the following condition: the transmission bandwidth is greater than a M, or b DMRS transmission symbols are included in one slot and a certain time interval exists between the b DMRS transmission symbols (e.g., 3 OFDM symbols are in line). Wherein, a can be 5, 6, 10, etc., to ensure a certain time domain resolution to improve the time domain large scale parameter estimation accuracy. b can be 2 or 4, etc., to ensure the frequency offset estimation precision. In the embodiment of the present application, the DMRS may be only used to estimate time delay domain large scale information, that is: only for indicating delay spread and average delay in QCL. Therefore, certain large-scale information can be obtained through the DMRS, and excessive requirements and influences on the transmission of the DMRS can be avoided. In this case, when the DMRS of a certain PDSCH transmission satisfies the definition of the effective DMRS, the processing time required by the UE is t1, and when the DMRS does not satisfy the definition of the effective DMRS, the processing time required by the UE is t2, and t1> t2.

Further, the present application may pre-agree on the behavior of the UE to estimate the large-scale characteristics (i.e., the large-scale parameters of the channel) on the DMRS. Specifically, DMRSs are grouped in advance, DMRS ports within one DMRS group may be used to estimate one set of large-scale parameters, and multiple DMRS groups are used to estimate multiple sets of large-scale parameters. This is to consider that, power allocations corresponding to signals transmitted on different DMRS ports on the network device side are different, that is, different large scale characteristics may occur. When the UE side performs time domain filtering, the estimation results on the same DMRS port transmitted at different times can be subjected to time domain filtering to form a relatively robust large-scale estimation result. Different DMRS ports may be independently time-domain filtered. Upon subsequent indication of a QCL hypothesis for the CSI-RS/DMRS, a specific DMRS port group ID/DMRS port ID may be indicated.

Still further, in the embodiment of the present application, a time window of the time domain filtering may be preset. Within a time window, the UE may filter based on the large scale information estimated by the DMRSs received at different times. When the time window is exceeded, the UE needs to re-estimate.

The scheme for determining QCL hypothesis information through DMRS provided in the present application is described below with reference to the accompanying drawings. Fig. 7 is a flowchart of a communication method according to an embodiment of the present application. As shown in fig. 7, the method includes:

701. and the terminal equipment receives the first DMRS sent by the network equipment.

The first DMRS is carried in a signal transmitted by the network device through the PDSCH or the PDCCH.

In a possible implementation manner, a bandwidth of the first DMRS is greater than a bandwidth threshold, or the first DMRS includes K DMRS transmission symbols in one slot, and a time interval between any two DMRS transmission symbols is greater than a time threshold, where K is an integer greater than 1. The bandwidth threshold may be 5M, 6M, 10M, etc., and the application is not limited thereto. The time threshold may be 2 OFDM symbols, 3 OFDM symbols, 4 OFDM symbols, etc., and the present application is not limited thereto. K can be 2, 4, etc., and the application is not limited. In this implementation, the bandwidth of the first DMRS is greater than a bandwidth threshold, or the first DMRS includes K DMRS transmission symbols in one slot and a time interval between any two DMRS transmission symbols is greater than a time threshold; it may be ensured that performing QCL estimation using the first DMRS can meet the processing time requirements of the signal carrying the first DMRS.

702. And receiving a second signal according to the second channel large-scale parameter.

And the second channel large-scale parameter is obtained based on the channel large-scale parameter of the first DMRS. For example, the second channel large-scale parameter is a channel large-scale parameter obtained based on measurement (or estimation) of the first DMRS. In some embodiments, the terminal device may derive the second channel large-scale parameter based on a measurement of the first DMRS. The second signal is a reference signal having a QCL relationship with the first DMRS. For example, the second signal has a QCL type relationship with the first DMRS. As another example, the second signal has a QCL type relationship with the first DMRS, for example. The second signal is from a network device.

In a possible implementation manner, the second signal is a demodulation reference signal or a channel state information reference signal CSI-RS.

Fig. 8 is a flowchart of another communication method according to an embodiment of the present application. The method flow in fig. 8 is one possible implementation of the method flow in fig. 7. As shown in fig. 8, the method includes:

801. the terminal equipment receives second indication information from the network equipment.

The second indication information indicates a QCL relationship between the second signal and the first DMRS.

In a possible implementation manner, the second indication information indicates a second transmission control indication TCI status, and the second TCI status includes a QCL relationship between the second signal and the first DMRS. In this implementation, the second indication information indicates a second TCI state with little resource overhead.

In one possible implementation manner, the first indication information includes an identifier of the second signal and an identifier of the first DMRS.

802. And the terminal equipment receives the first DMRS sent by the network equipment.

803. And the terminal equipment estimates the channel large-scale parameters of the first DMRS to obtain the second channel large-scale parameters.

One possible implementation of step 803 is as follows: after receiving the second indication information, the terminal device determines a QCL relationship between the second signal and the first DMRS according to the second indication information; and estimating the channel large-scale parameter of the first DMRS to obtain a second channel large-scale parameter.

One possible implementation of step 803 is as follows: and the terminal equipment estimates the channel large-scale parameter of the first DMRS to obtain a second channel large-scale parameter under the condition that the bandwidth of the first DMRS is greater than a bandwidth threshold value or the first DMRS comprises K DMRS transmission symbols in one time slot and the time interval between any two DMRS transmission symbols is greater than a time threshold value. That is, if the bandwidth of the first DMRS is less than or equal to a bandwidth threshold, or the number of DMRS transmission symbols included in one slot of the first DMRS is less than K, or a time interval between any two DMRS transmission symbols in the first DMRS is less than or equal to a time threshold, the terminal device does not estimate the channel large-scale parameter of the first DMRS.

804. And receiving a second signal according to the second channel large-scale parameter.

Fig. 7 and 8 mainly describe, from the terminal device side, the scheme for determining QCL hypothesis information through DMRS provided in the present application. The following describes a scheme for determining QCL hypothesis information through DMRS provided by the present application from a network device side. Fig. 9 is a flowchart of another communication method according to an embodiment of the present application. As shown in fig. 9, the method includes:

901. and the network equipment transmits the first DMRS to the terminal equipment.

In a possible implementation manner, a bandwidth of the first DMRS is greater than a bandwidth threshold, or the first DMRS includes K DMRS transmission symbols in one slot, and a time interval between any two DMRS transmission symbols is greater than a time threshold, where K is an integer greater than 1.

902. And sending the second indication information to the terminal equipment.

The second indication information indicates a quasi co-located QCL relationship between the second signal and the first DMRS. The sequence of the step 902 and the step 901 executed by the network device is not limited. The second indication information may be DCI or other downlink control information.

In a possible implementation manner, the second indication information indicates that a second transmission control indicates a second TCI state, and the second TCI state includes a QCL relationship between the second signal and the first DMRS.

In a possible implementation manner, the second indication information includes an identifier of the first DMRS and an identifier of the second signal.

In a possible implementation manner, the second indication information indicates a QCL relationship between the second signal and the first port group identity ID of the first DMRS or the first DMRS port ID. In the implementation manner, power allocations corresponding to signals sent by the network device on different DMRS ports or port groups are different, and the second indication information indicates a QCL relationship between the second signal and the first port group identity ID of the first DMRS or the first DMRS port ID, so as to more accurately estimate the large-scale parameter of the second channel. In some embodiments, a network device may pre-group DMRS, DMRS ports within one DMRS group may be used to estimate one set of large-scale parameters, and multiple DMRS groups are used to estimate multiple sets of large-scale parameters. This is to consider that, power allocations corresponding to signals transmitted on different DMRS ports on the network device side are different, that is, different large scale characteristics may occur. When the UE side performs time domain filtering, the estimation results on the same DMRS port transmitted at different times can be subjected to time domain filtering to form a relatively robust large-scale estimation result. And different DMRS ports independently perform time domain filtering. Upon subsequent indication of a QCL hypothesis for the CSI-RS/DMRS, a specific DMRS port group ID/DMRS port ID may be indicated.

903. And transmitting the second signal to the terminal equipment.

The foregoing describes a scheme for determining QCL hypothesis information through DMRS. The following introduces a scheme of performing time-domain filtering on the channel large-scale parameters transmitted at different times on the same DMRS port to form relatively robust channel large-scale parameters.

Fig. 10 is a flowchart of another communication method according to an embodiment of the present application. As shown in fig. 10, the method includes:

1001. and the terminal equipment receives the plurality of second DMRSs transmitted by the network equipment.

The plurality of second DMRS corresponds to a second DMRS port group identity, ID, or a second DMRS port ID. The plurality of second DMRSs refers to a plurality of different second DMRSs, e.g., a plurality of second DMRSs transmitted at different time instants.

In a possible implementation manner, a bandwidth of each of the plurality of second DMRS is greater than a bandwidth threshold, or each of the plurality of second DMRS includes K DMRS transmission symbols in one slot, and a time interval between any two DMRS transmission symbols is greater than a time threshold, where K is an integer greater than 1.

1002. The terminal equipment receives the third indication information from the network equipment.

The third indication information indicates a QCL relationship between the third signal and the second DMRS port group identity ID, or the third indication information indicates a QCL relationship between the third signal and the second DMRS port ID. And the terminal equipment receives the third indication information, and can timely acquire the QCL relationship between the third signal and the second DMRS port group ID or the QCL relationship between the third signal and the second DMRS port ID. The third indication information may be DCI or other downlink control information.

In some embodiments, after the terminal device receives the third indication information, it may learn a QCL relationship between the third signal and the second DMRS port group ID or a QCL relationship between the third signal and the second DMRS port ID, and further obtain a channel large-scale parameter of the third signal based on measurement of the plurality of second DMRS.

In a possible implementation manner, the third indication information indicates a third transmission control indication TCI status, where the third TCI status includes a QCL relationship between the third signal and the second DMRS port group ID, or the third TCI status includes a QCL relationship between the third signal and the second DMRS port ID. In this implementation, the third indication information indicates a third TCI state, with little resource overhead.

In one possible implementation manner, the third indication information includes the second DMRS port group ID or the second DMRS port ID.

1003. And receiving a third signal according to the third channel large-scale parameter.

And the third channel large-scale parameter is obtained by performing time-domain filtering on a plurality of channel large-scale parameters obtained by estimating the plurality of second DMRSs. The third signal is from a network device.

In a possible implementation manner, the third signal is a demodulation reference signal or a channel state information reference signal CSI-RS.

In one possible implementation, before receiving the third signal according to the third channel large-scale parameter, the terminal device performs the following operations: the terminal equipment performs channel estimation according to the plurality of second DMRSs received in a preset time window to obtain a plurality of channel large-scale parameters; and performing time domain filtering on the plurality of channel large-scale parameters to obtain the third channel large-scale parameter. The preset time window may be a time window set according to actual requirements, for example, 3ms, 5ms, 10ms, and the like. In the implementation mode, time domain filtering is carried out on a plurality of channel large-scale parameters to obtain a third channel large-scale parameter; a relatively robust large scale estimation result can be obtained.

Fig. 11 is a schematic structural diagram of a communication device according to an embodiment of the present application. The communication apparatus in fig. 11 is a terminal device or is included in a terminal device. As shown in fig. 11, the communication apparatus 1100 includes:

a transceiving unit 1101, configured to receive first indication information sent by a network device; the first indication information indicates a plurality of reference signals having a quasi-co-located QCL relationship with a first signal and a QCL weight for each of the plurality of reference signals;

a processing unit 1102, configured to obtain a first channel large-scale parameter by using the multiple reference signals and QCL weight processing of each of the multiple reference signals;

the transceiver 1101 is further configured to receive the first signal according to the first channel large-scale parameter.

In a possible implementation manner, the transceiver 1101 is further configured to receive the plurality of reference signals;

the processing unit 1102 is further configured to estimate a channel large-scale parameter by using the multiple reference signals, respectively, to obtain the multiple channel large-scale parameters;

the processing unit 1102 is specifically configured to perform synthesis processing on the multiple channel large-scale parameters by using the QCL weight of each of the multiple reference signals to obtain the first channel large-scale parameter.

Fig. 12 is a schematic structural diagram of a communication device according to an embodiment of the present application. The communication apparatus in fig. 12 is a network device or is included in a network device. As shown in fig. 12, the communication apparatus 1200 includes:

a processing unit 1201, configured to generate first indication information indicating a plurality of reference signals having a quasi-co-located QCL relationship with a first signal and a QCL weight for each of the plurality of reference signals;

a transceiving unit 1202, configured to send the first indication information to a terminal device; the first indication information is used for the terminal equipment to receive the first signal.

Referring to fig. 11, in one possible implementation, the communication device 1100 includes a transceiving unit 1101 and a processing unit 1102.

A transceiving unit 1101, configured to receive a first DMRS sent by a network device;

a processing unit 1102, configured to obtain a second channel large-scale parameter based on the channel large-scale parameter of the first DMRS;

the transceiver 1101 is further configured to receive a second signal according to the second channel large-scale parameter; the second signal is a reference signal having a QCL relationship with the first DMRS.

In a possible implementation manner, the processing unit 1102 is further configured to estimate a channel large-scale parameter by using the first DMRS, and obtain the second channel large-scale parameter.

Referring to fig. 12 again, in one possible implementation, the communication apparatus 1200 includes a processing unit 1201 and a transceiving unit 1202.

A transceiving unit 1202, configured to transmit a first DMRS to a terminal device; sending second indication information to the terminal device, wherein the second indication information indicates a quasi co-located QCL relationship between a second signal and the first DMRS;

a processing unit 1201 for generating the second signal;

the transceiver 1202 is further configured to transmit the second signal to the terminal device.

Referring again to fig. 11, in one possible implementation, the communication device 1100 includes a transceiving unit 1101 and a processing unit 1102.

A transceiver unit 1101, configured to receive a plurality of second demodulation reference signals DMRS transmitted by a network device, where the plurality of second DMRS correspond to a second DMRS port group identity ID or a second DMRS port ID;

a processing unit 1102, configured to perform time-domain filtering on the multiple channel large-scale parameters estimated by the multiple second DMRS to obtain a third channel large-scale parameter;

the transceiving unit 1101 is further configured to receive a third signal according to the third channel large-scale parameter.

In a possible implementation manner, the processing unit 1102 is further configured to perform channel estimation according to the plurality of second DMRSs received within a preset time window, so as to obtain the plurality of channel large-scale parameters.

In a possible implementation manner, the transceiver unit 1101 is further configured to receive third indication information from the network device, where the third indication information indicates a QCL relationship between the third signal and the second DMRS port group identity ID, or the third indication information indicates a QCL relationship between the third signal and the second DMRS port ID.

A transceiver unit 1202, configured to transmit a plurality of second DMRS to a terminal device, where the plurality of second DMRS corresponds to a second DMRS port group identity ID or a second DMRS port ID; transmitting third indication information to the terminal device, the third indication information indicating a QCL relationship between a third signal and the second DMRS port group identity representation ID or indicating a QCL relationship between the third signal and the second DMRS port ID;

a processing unit 1201 for generating the third signal;

the transceiver 1202 is further configured to transmit the third signal to the terminal device.

Fig. 13 is a schematic structural diagram of another communication device according to an embodiment of the present application. The communication device in fig. 13 may be the terminal device or the network device.

As shown in fig. 13. The communication apparatus 130 includes at least one processor 1320, configured to implement the function of the terminal device in the method provided in the embodiment of the present application; or, the method is used for implementing the network device function in the method provided by the embodiment of the application. The communication device 130 may also include a transceiver 1310. The transceiver 1310 is used to communicate with other devices/apparatuses over a transmission medium. The processor 1320 utilizes the transceiver 1310 to transceive data and/or signaling and is used to implement the methods in the above-described method embodiments.

Optionally, the communication device 130 may also include at least one memory 1330 for storing program instructions and/or data. A memory 1330 is coupled to the processor 1320. The coupling in the embodiments of the present application is an indirect coupling or a communication connection between devices, units or modules, and may be an electrical, mechanical or other form for information interaction between the devices, units or modules. The processor 1320 may operate in conjunction with the memory 1330. Processor 1320 may execute program instructions stored in memory 1330. At least one of the at least one memory may be included in the processor.

The embodiment of the present application does not limit the specific connection medium among the transceiver 1310, the processor 1320, and the memory 1330. In fig. 13, the memory 1330, the processor 1320, and the transceiver 1310 are connected by a bus 1340, which is indicated by a thick line in fig. 13, and the connection manner among other components is only for illustrative purposes and is not limited thereto. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 13, but this is not intended to represent only one bus or type of bus.

In the embodiments of the present application, the processor may be a general-purpose processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logic blocks disclosed in the embodiments of the present application. The general purpose processor may be a microprocessor or any conventional processor or the like. The steps of a method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in a processor.

It is understood that when the communication apparatus 130 is a terminal device, the transceiver 1310 implements the function of the transceiving unit 1101. Alternatively, when the communication apparatus 130 is a network device, the transceiver 1310 implements the function of the transceiving unit 1201. When the communication apparatus 130 is a terminal device, the processor 1320 realizes the function of the processing unit 1102. When the communication apparatus 130 is a network device, the processor 1320 realizes the functions of the processing unit 1202.

Fig. 14 is a schematic structural diagram of another communication device 140 according to an embodiment of the present disclosure. The communication device in fig. 14 may be the terminal device or the network device. As shown in fig. 14, the communication apparatus shown in fig. 14 includes a logic circuit 1401 and an interface 1402. The logic 1401 may be a chip, a processing circuit, an integrated circuit, or a system on chip (SoC) chip, and the interface 1402 may be a communication interface, an input/output interface, or the like. The interface 1402 is used to enable transmission and reception of data or signaling. In the embodiments of the present application, the logic circuit and the interface may also be coupled to each other. The embodiments of the present application are not limited to the specific connection manner of the logic circuit and the interface. In some embodiments of the present application, the logic and interfaces may be used to perform the functions or operations performed by the communication device described above, and the like.

The present application also provides a computer-readable storage medium having stored therein computer code which, when run on a computer, causes the computer to perform the method of the above-described embodiment.

The present application also provides a computer program product comprising computer code or a computer program which, when run on a computer, causes the method of the above embodiments to be performed.

The above description is only for the specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present application, and shall be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the above claims.

Claims

1. A downlink transmission method based on multi-station cooperation is characterized by comprising the following steps:

the method comprises the steps that terminal equipment receives first indication information sent by network equipment; the first indication information indicates a plurality of reference signals having a quasi-co-located QCL relationship with a first signal and QCL weights for each of the plurality of reference signals;

receiving the first signal according to a first channel large-scale parameter; the first channel large-scale parameter is obtained using the plurality of reference signals and QCL weights for each of the plurality of reference signals.

2. The method of claim 1, wherein the first signal is carried on a demodulation reference signal (DMRS) port, or wherein the first signal is carried on a Physical Downlink Shared Channel (PDSCH) port, or wherein the first signal is carried on a Physical Downlink Control Channel (PDCCH) port.

3. The method of claim 1, wherein the plurality of reference signals and the first signal each correspond to a first frequency band and a first transmission layer; or, the plurality of reference signals and the first signal each correspond to a first frequency band and a first data stream; alternatively, the plurality of reference signals and the first signal each correspond to a first transport layer and a first data stream.

4. The method of claim 1, wherein the bandwidth occupied by the first signal comprises a plurality of second frequency bands, and wherein the QCL relationships between the first signal and the plurality of reference signals comprise a QCL relationship between each second frequency band and at least one of the plurality of reference signals.

5. The method of any of claims 1 to 4, wherein the first indication information indicates a plurality of reference signals having a QCL relationship with the first signal, and wherein the QCL weights for each of the plurality of reference signals comprise: the first indication information indicates a plurality of first Transmission Control Indication (TCI) states, the plurality of first TCI states correspond to the plurality of reference signals one to one, and each of the first TCI states further includes QCL weights of the reference signals corresponding to the first TCI states.

6. A downlink transmission method based on multi-station cooperation is characterized in that the method is applied to a multi-station cooperation scene, and comprises the following steps:

generating, by a network device, first indication information indicating a plurality of reference signals having a quasi-co-located QCL relationship with a first signal and a QCL weight for each of the plurality of reference signals;

sending the first indication information to terminal equipment; the first indication information is used for the terminal equipment to receive the first signal.

7. The method of claim 6, wherein the first signal is carried on a demodulation reference signal (DMRS) port, or wherein the first signal is carried on a Physical Downlink Shared Channel (PDSCH) port, or wherein the first signal is carried on a Physical Downlink Control Channel (PDCCH) port.

8. The method of claim 6, wherein the plurality of reference signals and the first signal each correspond to a first frequency band and a first transmission layer; or, the plurality of reference signals and the first signal each correspond to a first frequency band and a first data stream; alternatively, the plurality of reference signals and the first signal each correspond to a first transport layer and a first data stream.

9. The method of claim 6, wherein the bandwidth occupied by the first signal comprises a plurality of second frequency bands, wherein the QCL relationships between the first signal and the plurality of reference signals are QCL relationships between the plurality of second frequency bands and the plurality of reference signals, and wherein the plurality of second frequency bands correspond one-to-one to the plurality of reference signals.

10. The method of any of claims 6 to 9, wherein the first indication information indicates a plurality of reference signals having a QCL relationship with the first signal, and wherein the QCL weight for each of the plurality of reference signals comprises: the first indication information indicates a plurality of first Transmission Control Indication (TCI) states, the plurality of first TCI states correspond to the plurality of reference signals one to one, and each of the first TCI states further includes QCL weights of the reference signals corresponding to the first TCI states.

11. The method of any of claims 6 to 10, wherein the first indication information comprises a plurality of identifiers and a plurality of QCL weights, the plurality of identifiers being identifiers of the plurality of reference signals, the plurality of identifiers having a one-to-one correspondence with the plurality of QCL weights, and wherein the plurality of QCL weights characterize a ratio of QCL hypothesis parameter values generated by the plurality of reference signals in synthesizing a QCL hypothesis.

12. A terminal device, comprising:

the receiving and sending unit is used for receiving first indication information sent by the network equipment; the first indication information indicates a plurality of reference signals having a quasi-co-located QCL relationship with a first signal and a QCL weight for each of the plurality of reference signals;

a processing unit, configured to obtain a first channel large-scale parameter by using the multiple reference signals and QCL weight processing of each of the multiple reference signals;

the transceiver unit is further configured to receive the first signal according to the first channel large-scale parameter.

13. The method of claim 12, wherein the first signal is carried on a demodulation reference signal (DMRS) port, or wherein the first signal is carried on a Physical Downlink Shared Channel (PDSCH) port, or wherein the first signal is carried on a Physical Downlink Control Channel (PDCCH) port.

14. The method of claim 12, wherein the plurality of reference signals and the first signal each correspond to a first frequency band and a first transmission layer; or, the plurality of reference signals and the first signal each correspond to a first frequency band and a first data stream; alternatively, the plurality of reference signals and the first signal each correspond to a first transport layer and a first data stream.

15. The method of claim 12, wherein the bandwidth occupied by the first signal comprises a plurality of second frequency bands, and wherein the QCL relationship between the first signal and the plurality of reference signals comprises a QCL relationship between each second frequency band and at least one of the plurality of reference signals.

16. The method of any of claims 12 to 15, wherein the first indication information indicates a plurality of reference signals having a QCL relationship with the first signal, and wherein the QCL weight for each of the plurality of reference signals comprises: the first indication information indicates a plurality of first Transmission Control Indication (TCI) states, the plurality of first TCI states correspond to the plurality of reference signals one to one, and each of the first TCI states further includes QCL weights of the reference signals corresponding to the first TCI states.

17. A network device, comprising:

a processing unit for generating first indication information indicating a plurality of reference signals having a quasi-co-located QCL relationship with a first signal and a QCL weight for each of the plurality of reference signals;

the receiving and sending unit is used for sending the first indication information to the terminal equipment; the first indication information is used for the terminal equipment to receive the first signal.

18. The method of claim 17, wherein the first signal is carried on a demodulation reference signal (DMRS) port, or wherein the first signal is carried on a Physical Downlink Shared Channel (PDSCH) port, or wherein the first signal is carried on a Physical Downlink Control Channel (PDCCH) port.

19. The method of claim 17, wherein the plurality of reference signals and the first signal each correspond to a first frequency band and a first transmission layer; or, the plurality of reference signals and the first signal each correspond to a first frequency band and a first data stream; alternatively, the plurality of reference signals and the first signal each correspond to a first transport layer and a first data stream.

20. The method of claim 17, wherein the bandwidth occupied by the first signal comprises a plurality of second frequency bands, wherein the QCL relationship between the first signal and the plurality of reference signals is a QCL relationship between the plurality of second frequency bands and the plurality of reference signals, and wherein the plurality of second frequency bands correspond one-to-one to the plurality of reference signals.

21. The method of any of claims 17 to 20, wherein the first indication information indicates a plurality of reference signals having a QCL relationship with the first signal, and wherein the QCL weight for each of the plurality of reference signals comprises: the first indication information indicates a plurality of first Transmission Control Indication (TCI) states, the plurality of first TCI states correspond to the plurality of reference signals one to one, and each of the first TCI states further includes QCL weights of the reference signals corresponding to the first TCI states.

22. The method of any of claims 17 to 20, wherein the first indication information comprises a plurality of identifiers and a plurality of QCL weights, the plurality of identifiers being identifiers of the plurality of reference signals, the plurality of identifiers having a one-to-one correspondence with the plurality of QCL weights, and wherein the plurality of QCL weights characterize a ratio of QCL hypothesis parameter values generated from the plurality of reference signals when synthesizing the QCL hypothesis.

23. A communications apparatus, comprising: a processor and a transceiver;

the transceiver is used for receiving signals or sending signals; the processor to execute computer-executable instructions stored by the memory to cause the communication device to perform the method of any of claims 1-5 or 6-11.

24. A computer-readable storage medium, for storing a computer program which, when run on a computer, causes the method of any one of claims 1-5 or 6-11 to be implemented.