CN114124173A - Method, device and storage medium for acquiring channel information - Google Patents

Abstract

Methods, apparatuses, terminal devices, network devices and media for channel information acquisition are provided. The method comprises the terminal device determining a first estimation result of a first channel arriving at the terminal device via the first network device from the second network device based on a first set of pilot signals received from the first network device. The method further comprises the terminal device sending first information relating to the first estimation result to the second network device. The method further comprises the terminal device determining a second estimation of a second channel between the first network device and the terminal device based on the second set of pilot signals received from the first network device and the first estimation. The method further comprises the terminal device sending second information related to the second estimation result to the second network device. In this way, the overhead of the pilot signal set and the delay of the reflected channel estimation can be reduced.

Description

Method, device and storage medium for acquiring channel information

technical field

The present disclosure relates to the field of communications, and more particularly, to a method, device and storage medium for channel information acquisition.

Background technique

The traditional multiple input and multiple output (MIMO) technology can significantly improve the spectral efficiency and transmission rate by configuring dozens of transceiver channels on the network device side, so it is listed as the fifth generation (5G). It is one of the core technologies of mobile communication new radio (NR). However, larger-scale transceiver channels need to configure more radio frequency chains, and each radio frequency chain includes mixers, digital-to-analog/analog-to-digital converters, etc., resulting in huge power consumption and cost. Therefore, in an actual communication system, the improvement of spectral efficiency by the traditional MIMO technology is approaching a bottleneck.

In order to solve the above-mentioned problems, a promising way is to add a network device with reflection function to the traditional MIMO system to form a new type of MIMO system. Examples of reflective network devices include, but are not limited to, intelligent reflecting surfaces (IRS). The new MIMO system can not only improve network coverage and network capacity, but also further improve spectral efficiency without significantly increasing power consumption and cost. In order to obtain the above advantages, it is necessary to know the complete channel information in the novel MIMO system. However, in the new MIMO system, the existing channel estimation schemes have high delay and overhead.

SUMMARY OF THE INVENTION

Example embodiments of the present disclosure provide solutions for channel information acquisition.

In a first aspect of the present disclosure, a channel information acquisition method implemented at a terminal device is provided. The method includes the terminal device determining a first estimation result of the first channel from the second network device via the first network device to the terminal device based on the first set of pilot signals received from the first network device. The method also includes the terminal device sending first information related to the first estimation result to the second network device. The method further includes the terminal device determining a second estimation result of the second channel between the first network device and the terminal device based on the second set of pilot signals received from the first network device and the first estimation result. The method further includes the terminal device sending second information related to the second estimation result to the second network device. The method can reduce the overhead of pilot signal set and the delay of reflection channel estimation.

In some embodiments, the first estimation result includes a first channel matrix, the second estimation result includes a second channel matrix, the third estimation result of the first channel includes a third channel matrix, and the third channel matrix=second channel matrix× The first channel matrix.

In some embodiments, the dimension of the first channel matrix is N×M, where N is the number of transmit ports or receive ports of the first network device, M is the number of transmit ports of the second network device, and the number of transmit ports of the second channel matrix is The dimension is NxN and is a diagonal matrix, and the dimension of the third channel matrix is NxM.

In some embodiments, the method further includes: the terminal device receiving a first signaling from the second network device, the first signaling indicating the content of the first information to be sent by the terminal device to the second network device; and the terminal device based on the first signaling A signaling to send the first information to the second network device.

In some embodiments, the first signaling further indicates the content of the second information to be sent by the terminal device to the second network device. In such an embodiment, the method further includes the terminal device sending the second information to the second network device based on the first signaling. The signaling overhead can be reduced by notifying the contents of the first information and the second information that indicate that the terminal device will send to the second network device through a single signaling.

In some embodiments, the method further includes: the terminal device receiving a second signaling from the second network device, the second signaling indicating the content of the second information to be sent by the terminal device to the second network device; and the terminal device based on the first The second signaling is to send the second information to the second network device.

In some embodiments, the content of the first information includes at least one of the following: amplitude information of each element in the first channel matrix, phase information of each element in the first channel matrix, and The number information of the multipath, the incident angle information of the multipath, the exit angle information of the multipath, the time delay information of the multipath, the Doppler frequency shift information of the multipath, and the gain information of the multipath.

In some embodiments, the content of the second information includes at least one of amplitude information and phase information of diagonal elements of the second channel matrix.

In some embodiments, the third precoding matrix and the fourth precoding matrix are determined based on the first information and the second information. The third precoding matrix is used by the first network device to precode data transmitted between the second network device and the terminal device. The fourth precoding matrix is used by the second network device to precode the data.

In some embodiments, the method further includes: before receiving the first set of pilot signals and the second set of pilot signals, the terminal device receives a third pilot signal from the first network device; the terminal device detects the third pilot signal and if the terminal device determines that the power is above the threshold power, the terminal device sends indication information to the second network device, the indication information instructs the second network device to send the first set of pilot signals and the second set of pilot signals.

In a second aspect of the present disclosure, a channel information acquisition method implemented at a second network device is provided. The method includes the second network device sending a first set of pilot signals to the first network device. The method also includes the second network device receiving the first information from the terminal device. The first information relates to a first estimation result of the first channel from the second network device via the first network device to the terminal device. The first estimation result is determined based on the first set of pilot signals. The method also includes sending the second set of pilot signals to the first network device by the second network device. The method also includes the second network device receiving second information from the terminal device. The second information is related to a second estimation result of the second channel between the first network device and the terminal device. The second estimation result is determined based on the second set of pilot signals. The method can reduce the overhead of pilot signal set and the delay of reflection channel estimation.

In some embodiments, the first estimation result includes a first channel matrix, the second estimation result includes a second channel matrix, the third estimation result of the first channel includes a third channel matrix, and the third channel matrix=second channel matrix× The first channel matrix.

In some embodiments, the dimension of the first channel matrix is N×M, in some embodiments, N is the number of transmit ports or receive ports of the first network device, M is the number of transmit ports of the second network device, The dimension of the second channel matrix is NxN and is a diagonal matrix, and the dimension of the third channel matrix is NxM.

In some embodiments, the method further includes the second network device sending the first signaling to the terminal device. The first signaling indicates the content of the first information to be sent by the terminal device to the second network device. The first information is sent based on the first signaling.

In some embodiments, the first signaling further indicates the content of the second information to be sent by the terminal device to the second network device, the second information being sent based on the first signaling.

In some embodiments, the method further includes sending the second signaling to the terminal device by the second network device. The second signaling indicates the content of the second information to be sent by the terminal device to the second network device. The second information is sent based on the second signaling.

In some embodiments, the content of the first information includes at least one of the following: amplitude information of each element in the first channel matrix, phase information of each element in the first channel matrix, and The number information of the multipath, the incident angle information of the multipath, the exit angle information of the multipath, the time delay information of the multipath, the Doppler frequency shift information of the multipath, and the gain information of the multipath.

In some embodiments, the content of the second information includes at least one of amplitude information and phase information of diagonal elements of the second channel matrix.

In some embodiments, the method further includes: the second network device sends a third signaling to the first network device, so that the first network device uses the preconfigured first precoding matrix to perform the first signaling based on the third signaling. The set of frequency signals is precoded. Since the first precoding matrix is pre-configured, there is no need for the second network device to send signaling for indicating the first precoding matrix to the first network device, so that signaling overhead can be reduced.

In some embodiments, the method further includes: the second network device sends a fourth signaling to the first network device, so that the first network device uses the first precoding matrix to perform a second pilot signal set based on the fourth signaling precoding. Since the first precoding matrix is pre-configured, there is no need for the second network device to send signaling for indicating the first precoding matrix to the first network device, so that signaling overhead can be reduced.

In some embodiments, the method further includes: the second network device receives the first information from the terminal device to determine the second precoding matrix; the second network device sends a fifth message indicating the second precoding matrix to the first network device and the second network device sends sixth signaling to the first network device, so that the first network device uses the second precoding matrix to precode the second pilot signal set based on the sixth signaling.

In some embodiments, the method further includes: the second network device determining a third precoding matrix and a fourth precoding matrix based on the first information and the second information. The third precoding matrix is used by the first network device to precode data transmitted between the second network device and the terminal device. The fourth precoding matrix is used by the second network device to precode the data. The determination by the second network device of the precoding matrix for precoding the data based on the first information and the second information may reduce the complexity of the terminal device.

In some embodiments, the method further includes: the second network device sending seventh signaling indicating the third precoding matrix to the first network device; and the second network device sending eighth signaling to the first network device such that The first network device precodes the data by using the third precoding matrix based on the eighth signaling.

In some embodiments, the method further comprises: prior to sending the first set of pilot signals and the second set of pilot signals, the second network device sending a third pilot signal to the first network device; and receiving an indication from the terminal device information, the indication information instructs the second network device to send the first pilot signal set and the second pilot signal set, and the indication information is sent in response to the terminal device detecting that the power of the third pilot signal is above the threshold power.

In a third aspect of the present disclosure, a channel information acquisition method implemented at a first network device is provided. The method includes the first network device receiving a first set of pilot signals from the second network device. The method also includes the first network device receiving a second set of pilot signals from the second network device. The method also includes the first network device sending the first set of pilot signals and the second set of pilot signals to the terminal device. The method can reduce the overhead of pilot signal set and the delay of reflection channel estimation.

In some embodiments, the method further includes: the first network device receives a third signaling from the second network device; the first network device uses a preconfigured first precoding matrix to perform the first pilot based on the third signaling The set of signals is precoded; and the first network device sends the precoded first set of pilot signals to the terminal device.

In some embodiments, the method further includes: the first network device receives fourth signaling from the second network device; based on the fourth signaling, the first network device uses the first precoding matrix to perform a second pilot signal set precoding; and the first network device sends the precoded second set of pilot signals to the terminal device.

In some embodiments, the method further includes: the first network device receiving, from the second network device, fifth signaling indicating a second precoding matrix, the second precoding matrix being determined based on the first information, the first information being associated with the second network device The second network device is related to a first estimation result of the first channel that reaches the terminal device via the first network device, and the first estimation result is determined based on the first set of pilot signals; the first network device receives the sixth signal from the second network device. command; the first network device precodes the second pilot signal set using the second precoding matrix based on the sixth signaling; and the first network device sends the precoded second pilot signal set to the terminal device.

In some embodiments, the method further includes: the first network device receiving from the second network device seventh signaling indicating a third precoding matrix, the third precoding matrix being determined based on the first information and the second information, the first information related to a first estimation result of the first channel from the second network device to the terminal device via the first network device, the first estimation result is determined based on the first set of pilot signals, the second information is related to the first network device and the A second estimation result of the second channel between the terminal devices is related, and the second estimation result is determined based on the second pilot signal set and the first estimation result; the first network device receives eighth signaling from the second network device; and The first network device uses the third precoding matrix to precode the data transmitted between the second network device and the terminal device based on the eighth signaling.

In a fourth aspect of the present disclosure, a terminal device is provided. The terminal device includes a processor and a memory. Computer program instructions are stored. The memory and computer program instructions are configured, with the processor, to cause the terminal device to perform the method according to the first aspect of the present disclosure.

In a fifth aspect of the present disclosure, a second network device is provided. The second network device includes a processor and a memory. Computer program instructions are stored. The memory and computer program instructions are configured, with the processor, to cause the second network device to perform the method according to the second aspect of the present disclosure.

In a sixth aspect of the present disclosure, a first network device is provided. The first network device includes a processor and a memory. Computer program instructions are stored. The memory and computer program instructions are configured, with the processor, to cause the first network device to perform the method according to the third aspect of the present disclosure.

In a seventh aspect of the present disclosure, a computer-readable medium is provided. The computer-readable medium stores machine-executable instructions. The machine-executable instructions, when executed by the terminal device, cause the terminal device to perform the method according to the first aspect of the present disclosure.

In an eighth aspect of the present disclosure, a computer-readable medium is provided. The computer-readable medium stores machine-executable instructions. The machine-executable instructions, when executed by the terminal device, cause the terminal device to perform the method according to the second aspect of the present disclosure.

In a ninth aspect of the present disclosure, a computer-readable medium is provided. The computer-readable medium stores machine-executable instructions. The machine-executable instructions, when executed by the terminal device, cause the terminal device to perform the method according to the third aspect of the present disclosure.

Description of drawings

The features, advantages, and other aspects of various implementations of the present disclosure will become more apparent when taken in conjunction with the accompanying drawings and with reference to the following detailed description. Several implementations of the present disclosure are shown herein by way of example and not by way of limitation, in the accompanying drawings:

1 shows a schematic block diagram of a MIMO system in which embodiments of the present disclosure may be implemented;

FIG. 2 illustrates an example architecture of an IRS according to some embodiments of the present disclosure;

Fig. 3 shows the conventional scheme of reflection channel estimation;

4 shows a signaling interaction diagram of a channel information acquisition process according to some embodiments of the present disclosure;

5 illustrates a transformation process of a precoded first set of pilot signals according to some embodiments of the present disclosure;

6 shows a flowchart of a method for acquiring channel information according to some embodiments of the present disclosure;

FIG. 7 shows a flowchart of a method for acquiring channel information according to other embodiments of the present disclosure;

FIG. 8 shows a flowchart of a method for acquiring channel information according to further embodiments of the present disclosure; and

9 shows a block diagram of an example electronic device according to some embodiments of the present disclosure.

In the various figures, the same or similar reference numbers refer to the same or similar elements.

Detailed ways

Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While certain embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be construed as limited to the embodiments set forth herein, but rather are provided for the purpose of A more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes, and are not intended to limit the protection scope of the present disclosure.

In the description of embodiments of the present disclosure, the term "comprising" and the like should be understood as open-ended inclusion, ie, "including but not limited to". The term "based on" should be understood as "based at least in part on". The terms "one embodiment" or "the embodiment" should be understood to mean "at least one embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

Embodiments of the present disclosure may be implemented in accordance with any suitable communication protocol, including, but not limited to, cellular communication protocols such as fourth generation (4G) and fifth generation (5G), protocols such as Institute of Electrical and Electronics Engineers (IEEE) 802.11, and the like. Wireless local area network communication protocol, and/or any other protocol currently known or developed in the future. The technical solutions of the embodiments of the present disclosure are applicable to any suitable communication system, such as: General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, Frequency Division Duplex (FDD) system, Time Division Duplex (TDD), general Mobile communication system (UMTS), Narrowband Internet of Things (NB-IoT) communication system, future fifth generation (5G) system or New Radio (NR), etc.

For illustrative purposes, embodiments of the present disclosure are described below in the context of the 3rd Generation Partnership Project (3GPP) communication system for 5G. However, it should be understood that the embodiments of the present disclosure are not limited to being applied to the 3GPP communication system of 5G, but may be applied to any communication system having similar problems, such as a wireless local area network (WLAN), a wired communication system, or a future development other communication systems, etc.

The specific embodiments of the present disclosure are mainly implemented in a MIMO system. Before introducing specific embodiments of the present disclosure, for ease of understanding, an example architecture of a MIMO system is first described.

Figure 1 shows a schematic block diagram of a MIMO system 100 in which embodiments of the present disclosure may be implemented. As shown in the figure, the MIMO system 100 includes a first network device 110 , a second network device 120 and a terminal device 130 .

The first network device 110 receives signals or data from the second network device 120 . In some embodiments, the first network device 110 may reflect the received signal or data to the terminal device 130 . In some embodiments, the first network device 110 may precode the received signal or data, and transmit the precoded signal or data to the terminal device 130 . In some embodiments, the first network device 110 may receive signals or data transmitted in the form of electromagnetic waves from the second network device 120, and adjust at least one of the amplitude and phase of the received electromagnetic waves at the radio frequency side to adjust the received electromagnetic waves. The received signal or data is precoded. Further, the first network device 110 may transmit the precoded signal or data to the terminal device 130 by radiating electromagnetic waves whose amplitude and phase are adjusted to the terminal device 130 .

In some embodiments, the first network device 110 may be an IRS. An example architecture of the IRS will be described below in particular in conjunction with FIG. 2 . It should be understood that the architecture of the IRS shown in Figure 2 is only an example. As shown in FIG. 2 , the IRS 200 includes an outer layer 210 , a middle layer 220 , an inner layer 230 , and a controller 240 . In some embodiments, the outer layer 210 may include a plurality of array elements 212 composed of electromagnetic metamaterials. For example, the outer layer 210 may include hundreds or thousands of array elements 212 . It will be appreciated that the number of array elements 212 is merely an example and is not intended to suggest any limitation. According to actual needs, the outer layer 210 may include any appropriate number of array elements 212 .

A PIN diode (not shown) may be embedded in each array element. The intermediate layer 220 may include a copper plate for avoiding leakage of signal energy. The inner layer 230 may include a control circuit board. The control circuit board may be coupled to PIN diodes in outer layer 210 . The bias voltage of the PIN diode can be controlled by the control circuit board, so that the PIN diode is switched between an on state and an off state, so as to adjust at least one of the amplitude and the phase of the incident signal.

The controller 240 is coupled with the inner layer 230 . In some embodiments, the controller 240 may be implemented by a field programmable gate array (FPGA). The controller 240 may communicate with the second network device 120 through a wireless link or a wired link. For example, the controller 240 may receive a control signal from the second network device 120 shown in FIG. 1 to trigger the control circuit board of the inner layer 230 to control the bias voltage of the PIN diode.

It should be understood that the IRS is only an example of the first network device 110 . In some other embodiments, the first network device 110 may be a radio frequency repeater. A radio frequency repeater refers to a relay enhancement device that uses wireless means to receive, amplify and transmit signals. It should be understood that the IRS and the radio frequency repeater are only examples of the first network device 110, and the protection scope of the present disclosure is not limited thereto.

Continue to refer to Figure 1 . The second network device 120 is an entity or node that can communicate with the first network device 110 and the terminal device 130 . The second network device 120 may be, for example, a radio access network (RAN) device. As an example, the second network device 120 may include a macro base station, a micro base station, a pico base station, a femto base station, a relay station, an access point, a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), etc. Wait.

The second network device 120 may communicate with the terminal device 130 through the channel 122 between it and the terminal device 130 . Hereinafter, the channel 122 between the second network device 120 and the terminal device 130 is also referred to as a direct channel 122 . Furthermore, the second network device 120 may communicate with the terminal device 130 through a channel from the second network device 120 to the terminal device 130 via the first network device 110 . In the following, the channel from the second network device 120 to the terminal device 130 via the first network device 110 is also referred to as a reflection channel 124 (also referred to as a first channel). As shown in FIG. 1 , the reflection channel 124 includes two channels, namely the channel 124-1 between the second network device 120 and the first network device 110 and the channel 124-2 between the first network device 110 and the terminal device 130 (also known as the second channel). In some embodiments, in order to improve spectral efficiency and transmission rate, the second network device 120 may precode the signal or data to be transmitted.

Terminal device 130 may sometimes be referred to as user equipment (UE). The terminal device 130 may be any type of mobile terminal, fixed terminal or portable terminal. By way of example, terminal device 130 may include a mobile handset, site, unit, device, mobile terminal (MT), subscribing station (SS), portable subscribing station (PSS), internet node, communicator, desktop computer, laptop computer, Notebook computers, tablet computers, personal communication system (PCS) devices, personal navigation devices, personal digital assistants (PDAs), positioning devices, radio receivers, e-book devices, gaming devices, Internet of Things (IoT) devices, in-vehicle devices, aircraft, virtual reality (VR) devices, augmented reality (AR) devices, wearable devices, terminal devices in 5G networks or any terminal device in the future evolved public land mobile network (PLMN), other devices that can be used for communication, or any combination of the above. The embodiments of the present disclosure do not limit this.

The terminal device 130 can not only communicate with the second network device 120 via the reflection channel 124 , but also communicate with the second network device 120 via the direct transmission channel 122 . For example, the terminal device 130 may not only receive data precoded by the second network device 120 via the direct channel 122 but also receive data precoded by the first network device 110 via the reflected channel 124 . In order to perform joint precoding between the second network device 120 and the first network device 110, the second network device 120 needs to obtain the information of the direct channel 122 between the second network device 120 and the terminal device 130, and also need to obtain the information from the direct channel 122 between the second network device 120 and the terminal device 130. The second network device 120 reaches the information of the reflection channel 124 of the terminal device 130 via the first network device 110 .

Traditionally, in order to obtain the information of the reflected channel, the terminal equipment needs to measure the pilot signal sent by the network equipment in a time-division manner. In the following, the conventional scheme of reflection channel estimation will be described in detail with reference to FIG. 3 . As shown in FIG. 3 , first, the network device informs the IRS 300 to turn off all array elements, and sends a pilot signal. The terminal device determines the estimation result of the direct transmission channel between the network device and the terminal device. After that, the network device informs the IRS 300 to turn on each array element one by one, and sends a pilot signal to the IRS 300 in a time-division manner. The terminal device determines, based on the pilot signal reflected by each array element, the estimation result of the channel between the corresponding array element and the terminal device when each array element is turned on. For example, the network device may first notify the IRS 300 to turn on the array element 310, and send a pilot signal to the IRS 300. The terminal device estimates the channel between the array element 310 and the terminal device when the array element 310 is turned on based on the pilot signal reflected by the array element 310 . In a similar manner, the terminal device can determine the estimation results of the channel between the remaining array elements on the IRS 300 and the terminal device. Further, the terminal device combines the obtained estimation results of the channel between each array element and the terminal device. Then, the terminal device can obtain the estimation result of the reflected channel by subtracting the estimation result of the direct transmission channel obtained previously from the estimation result of the combined channel.

It can be seen that the traditional solution needs to open the array elements of the IRS one by one to estimate the corresponding channel. Assuming that the number of array elements of the IRS is N (N is a positive integer), the pilot signal overhead of the conventional scheme is N+1 times that of the MIMO system without IRS. In a practical configuration, the number of elements of the IRS can be between 256 and 1024. This means that the pilot signal overhead for downlink channel estimation of a MIMO system with IRS is hundreds of times that of a MIMO system without IRS. In addition, sending the pilot signal to the IRS 300 by the network device in a time-division manner also increases the delay of the reflection channel estimation.

At least for the above problems and potential other related problems, the embodiments of the present disclosure propose a solution for acquiring channel information. According to this scheme, the acquisition of channel information is divided into two stages. In the first stage, the terminal device determines a first estimation result of the feedback channel from the second network device via the first network device to the terminal device based on the first set of pilot signals received from the first network device (eg IRS), And the first information related to the first estimation result is sent to the second network device. In the second stage, the terminal device determines, based on the second pilot signal set received from the first network device and the channel estimation result of the first stage (ie, the first estimation result of the feedback channel), that the first network device and the terminal are set up. The second estimation result of the channel between them is sent, and the second information related to the second estimation result is sent to the second network device. Thus, the second network device may determine, based on the received first information and the second information, to be respectively used by the first network device and the second network device to precode the data transmitted between the second network device and the terminal device the precoding matrix. This scheme can effectively reduce the overhead of pilot signals and the delay of reflection channel estimation. Embodiments of the present disclosure will be described in detail below with reference to FIGS. 4 to 8 .

4 illustrates a signaling interaction diagram of an example process 400 for channel information acquisition according to an embodiment of the present disclosure. For discussion purposes, the example process 400 will be described with reference to various elements shown in FIGS. 1 and 2 . However, it should be understood that the example process 400 may also be performed between a network device and an end device in any other communication scenario.

As shown in FIG. 4 , the second network device 120 sends ( 411 ) a first set of pilot signals to the first network device 110 . Accordingly, the first network device 110 receives ( 412 ) the first set of pilot signals from the second network device 120 . In some embodiments, the first set of pilot signals may include a set of channel state information reference signals (CSI-RS). In some other embodiments, the first set of pilot signals may include any suitable set of pilot signals that may be used for channel estimation.

In some embodiments, after receiving the first set of pilot signals, the first network device 110 reflects the received first set of pilot signals to the terminal device 130 without precoding the received first set of pilot signals .

In other embodiments, after receiving the first set of pilot signals, optionally, the first network device 110 may precode (413) the first set of received pilot signals to generate a precoded set of pilot signals. The first set of pilot signals. In the following, description will be given by taking the first network device 110 precoding the first pilot signal set and sending the generated precoded first pilot signal set to the terminal device 130 as an example. However, it should be understood that the solution of the present disclosure is also applicable to the scenario in which the first network device 110 reflects the received first pilot signal set to the terminal device 130 .

In some embodiments, the first network device 110 may use the first precoding matrix to precode the first set of pilot signals. Details about the first precoding matrix will be described in detail in the section "Example Implementation of Reflection Channel Estimation" below.

In some embodiments, the first precoding matrix may be preconfigured. For example, the first precoding matrix may be pre-stored in the controller 240 as shown in FIG. 2 . Optionally, the second network device 120 may send ( 401 ) signaling (also referred to as “third signaling” hereinafter) to the first network device 110 to notify the first network device 110 to use the preconfigured first The precoding matrix precodes the first set of pilot signals. Accordingly, the first network device 110 receives ( 402 ) the third signaling from the second network device 120 . Then, the first network device 110 uses the preconfigured first precoding matrix to precode the first pilot signal set based on the third signaling. Since the first precoding matrix is pre-configured, it is unnecessary for the second network device 120 to send signaling for indicating the first precoding matrix to the first network device 110, so that signaling overhead can be reduced.

In some embodiments, the third signaling may include one of: Radio Resource Control (RRC) signaling, Medium Access Control (MAC) Control Information Element (CE), and Downlink Control Information (DCI).

In other embodiments, the first precoding matrix may be determined by the terminal device 130 according to a previous channel estimation result and fed back to the second network device 120 . In such an embodiment, the second network device 120 may send signaling to the first network device 110 to indicate the first precoding matrix.

After generating the precoded first set of pilot signals, the first network device 110 transmits ( 414 ) the precoded first set of pilot signals to the terminal device 130 . Accordingly, the terminal device 130 receives ( 415 ) the precoded first set of pilot signals from the first network device 110 .

In some embodiments, optionally, before sending the first set of pilot signals, the second network device 120 may send ( 403 ) signaling to the terminal device 130 to instruct the terminal device 130 to start receiving the precoded first set of signals. A set of pilot signals. In the following, this signaling is also referred to as "first signaling". Accordingly, the terminal device 130 receives ( 404 ) the first signaling from the second network device 120 .

In some embodiments, the first signaling may include one of the following: RRC signaling, MAC CE, and DCI.

In some embodiments, the first signaling may indicate a time-frequency location of the first set of pilot signals. Further, the terminal device 130 may receive the precoded first set of pilot signals from the first network device 110 based on the first signaling.

After receiving the precoded first set of pilot signals, terminal device 130 determines ( 416 ) an estimation result (also referred to as a first estimation result) of feedback channel 124 based on the precoded first set of pilot signals . In some embodiments, the estimation result of the feedback channel 124 includes the first channel matrix. Details on how the terminal device 130 determines the estimation result of the feedback channel 124 will be described in detail in the "Example Implementation of Reflection Channel Estimation" section below.

After determining the estimation result of the feedback channel 124 , the terminal device 130 sends ( 417 ) information (also referred to as first information) related to the estimation result of the feedback channel 124 to the second network device 120 . Accordingly, the second network device 120 receives (418) the first information.

In some embodiments, the first signaling further indicates the content of the first information to be sent by the terminal device 130 to the second network device 120 . Further, the terminal device 130 may send the first information to the second network device 120 based on the first signaling.

In some embodiments, the content of the first information may include at least one of the following: amplitude information of each element in the first channel matrix and phase information of each element in the first channel matrix. In other embodiments, the content of the first information may further include at least one of the following: information on the number of multipaths of the reflection channel 124 , information on the incidence angles of the multipaths, information on the exit angles of the multipaths, and time information on the multipaths. delay information, Doppler shift information of multipath and gain information of multipath.

It should be understood that the above descriptions are only some examples of the first information related to the estimation result of the reflected channel 124, and the scope of the present disclosure is not limited in this regard. Depending on the specific application scenario or configuration, the terminal device 130 may determine any appropriate information related to the estimation result of the reflected channel 124 and send it to the second network device 120 .

After sending the first set of pilot signals, the second network device 120 sends ( 431 ) the second set of pilot signals to the first network device 110 . Accordingly, the first network device 110 receives ( 432 ) a second set of pilot signals from the second network device 120 . In some embodiments, the second set of pilot signals may comprise a set of channel state information reference signals (CSI-RS). In some other embodiments, the second set of pilot signals may include any suitable set of pilot signals that may be used for channel estimation.

After receiving the second pilot signal set, optionally, the first network device 110 may precode the received second pilot signal set (433) to generate a precoded second pilot signal set. In the following, description will be given by taking the first network device 110 precoding the second pilot signal set and sending the generated precoded second pilot signal set to the terminal device 130 as an example. However, it should be understood that the solution of the present disclosure is also applicable to the scenario in which the first network device 110 reflects the received second pilot signal set to the terminal device 130 .

In some embodiments, the first network device 110 may use the aforementioned first precoding matrix to precode the second set of pilot signals. In such an embodiment, optionally, the second network device 120 may send (421) signaling (hereinafter also referred to as "fourth signaling") to the first network device 110 to instruct the first network device 110 Precode the second set of pilot signals using the aforementioned first precoding matrix. Accordingly, the first network device 110 receives ( 422 ) the fourth signaling from the second network device 120 . Then, the first network device 110 uses the aforementioned first precoding matrix to precode the second pilot signal set based on the fourth signaling. That is, the first network device 110 uses the same precoding matrix to precode the first pilot signal set and the second pilot signal set. Therefore, the second network device 120 does not need to send signaling to the first network device 110 to indicate a precoding matrix for precoding the second pilot signal set, so that signaling overhead can be reduced.

In some embodiments, the first network device 110 may use a second precoding matrix different from the aforementioned first precoding matrix to precode the second set of pilot signals. In some embodiments, the second precoding matrix may be determined by terminal device 130 based on the precoded first set of pilot signals. Details about the second precoding matrix will be described in detail in the "Example Implementation of Reflection Channel Estimation" section below. In such an embodiment, terminal device 130 may determine a precoding matrix indication (PMI) associated with the second precoding matrix based on the precoded first set of pilot signals. In the following, the precoding matrix indication associated with the second precoding matrix is also referred to as "first precoding matrix indication". After determining the first precoding matrix indication, the terminal device 130 may send the first precoding matrix indication to the second network device 120 .

In some embodiments, the second network device 120 may indicate in the first signaling that the terminal device 130 will send the first precoding matrix indication to the second network device 120 . Thus, the terminal device 130 may send the first precoding matrix indication to the second network device 120 based on the first signaling.

In the embodiment employing the second precoding matrix, before sending the second set of pilot signals, the second network device 120 may send signaling (not shown) to the first network device 110 indicating the second precoding matrix. This signaling is also referred to as "fifth signaling" in the following. Further, the second network device 120 sends signaling (not shown) to the first network device 110 to instruct the first network device 110 to precode the second set of pilot signals using the second precoding matrix. This signaling is also referred to as "sixth signaling" in the following. Thus, the first network device 110 may use the second precoding matrix to precode the second pilot signal set based on the sixth signaling.

In some embodiments, the fifth signaling and the sixth signaling may be the same signaling. That is, the second network device 120 indicates the second precoding matrix and instructs the first network device 110 to precode the second set of pilot signals using the second precoding matrix in a single signaling. Thereby, signaling overhead can be reduced.

After generating the precoded second set of pilot signals, the first network device 110 transmits ( 434 ) the precoded second set of pilot signals to the terminal device 130 . Accordingly, the terminal device 130 receives ( 435 ) the precoded second set of pilot signals from the first network device 110 .

In some embodiments, the first signaling sent by the second network device 120 to the terminal device 130 before sending the first set of pilot signals may indicate a predetermined time interval to instruct the terminal device 130 to start the A network device 110 receives the precoded second set of pilot signals. Thereby, the terminal device 130 may receive the precoded second set of pilot signals from the first network device 110 after the predetermined time interval based on the first signaling.

In other embodiments, the first signaling may indicate the time-frequency location of the second pilot signal set. In turn, the terminal device 130 may receive the precoded second set of pilot signals from the first network device 110 based on the first signaling.

Since the terminal device 130 can receive both the precoded first set of pilot signals and the precoded second set of pilot signals from the first network device 110 based on a single signaling (ie, the first signaling), it can Reduce signaling overhead.

In still other embodiments, optionally, before sending the second set of pilot signals, the second network device 120 may send ( 423 ) additional signaling to the terminal device 130 to instruct the terminal device 130 to start receiving the preset A set of encoded second pilot signals. In the following, this additional signaling is also referred to as "second signaling". Accordingly, the terminal device 130 receives ( 424 ) the second signaling from the second network device 120 .

In some embodiments, the second signaling may indicate the time-frequency location of the second set of pilot signals. In turn, the terminal device 130 may receive the precoded second set of pilot signals from the first network device 110 based on the second signaling.

In an embodiment in which the second network device 120 sends both the first signaling and the second signaling, the first signaling and the second signaling may each include an indicator to distinguish the first signaling and the second signaling. signaling. For example, the second network device 120 may set the indicator to 0 to indicate that the sent signaling is the first signaling; and set the indicator to 1 to indicate that the sent signaling is the second signaling. Of course, the second network device 120 may set this indicator to any suitable value to differentiate the first signaling from the second signaling.

Continue to refer to FIG. 4 . After receiving the precoded second set of pilot signals, the terminal device 130 determines ( 436 ) the first network device 110 and the terminal device based on the precoded second set of pilot signals and the estimation result of the channel 124 - 1 The estimation result (also referred to as the second estimation result) of the channel 124-2 between 130. In some embodiments, the second estimation result includes a second channel matrix. Details on how the terminal device 130 determines the estimation result of the channel 124-2 will be described in detail in the section "Example Implementation of Reflected Channel Estimation" below.

As mentioned above, the terminal device 130 can not only communicate with the second network device 120 via the reflection channel 124 , but also communicate with the second network device 120 via the direct transmission channel 122 . In other words, when the second network device 120 sends the first set of pilot signals, the terminal device 130 can not only receive the precoded first set of pilot signals from the first network device 110 via the reflection channel 124, but also can receive the precoded first set of pilot signals via the direct channel 124. The transmission channel 122 receives the first set of pilot signals from the second network device 120 . That is, what the terminal device 130 receives is the precoded first pilot signal set and the superimposed signal of the first pilot signal set (hereinafter also referred to as "first superimposed signal"). Similarly, when the second network device 120 sends the second pilot signal set, the terminal device 130 receives the precoded second pilot signal set and the superimposed signal of the second pilot signal set (in the following Also referred to herein as the "second superimposed signal"). Therefore, in order to determine the estimation result of the reflected channel 124 based on the precoded first set of pilot signals and the precoded second set of pilot signals, the terminal device 130 needs to obtain the estimation result of the reflected channel 124 from the first superimposed signal and the second superimposed signal, respectively. The first set of pilot signals and the second set of pilot signals are removed to obtain a first set of precoded pilot signals and a second set of precoded pilot signals. Terminal device 130 may employ any method known or developed in the future to remove the first set of pilot signals and the second set of pilot signals from the first superimposed signal and the second superimposed signal, and the scope of the present disclosure is not limited in this regard. limit.

In some embodiments, after determining the estimation result of the channel 124-2, the terminal device 130 may send (437) to the second network device 120 information related to the estimation result of the channel 124-2 (also referred to as the second network device 120). information). Accordingly, the second network device 120 receives (438) information related to the estimation result of the channel 124-2. In some embodiments, in order for the terminal device 130 to send the information related to the estimation result of the reflection channel 124 to the second network device 120, the second network device 120 may indicate in the first signaling or the second signaling.

In some embodiments, the first signaling or the second signaling may indicate the content of the second information to be sent by the terminal device 130 to the second network device 120 . Further, the terminal device 130 may send the second information to the second network device 120 based on the first signaling or the second signaling.

In some embodiments, the content of the second information may include at least one of amplitude information and phase information of diagonal elements of the second channel matrix. It should be understood that the above descriptions are only some examples of the second information, and the scope of the present disclosure is not limited in this regard. Depending on the specific application scenario or configuration, the terminal device 130 may determine any appropriate information related to the estimation result of the channel 124 - 2 and send it to the second network device 120 .

In some embodiments, after receiving the first information and the second information, optionally, the second network device 120 may determine (439) the third precoding matrix and the fourth precoding matrix based on the first information and the second information. encoding matrix. The third precoding matrix is used by the first network device 110 to precode data transmitted between the second network device 120 and the terminal device 130 . The fourth precoding matrix is used by the second network device 120 to precode data transmitted between the second network device 120 and the terminal device 130 . Details about the third precoding matrix and the fourth precoding matrix will be described in detail in the "Example Implementation of Data Transmission Phase" section below.

It should be understood that the use of the first information and the second information to determine the third precoding matrix and the fourth precoding matrix is only one example of the use of the first information and the second information. According to specific application scenarios or configurations, the second network device 120 may use the first information and the second information for other purposes, and the scope of the present disclosure is not limited in this respect.

In some embodiments, after the third precoding matrix is determined, the second network device 120 may send signaling (hereinafter also referred to as "seventh signaling") indicating the third precoding matrix to the first network device 110 ”). Correspondingly, the first network device 110 receives the seventh signaling indicating the third precoding matrix. The second network device 120 may send the eighth signaling to the first network device 110, so that the first network device 110 uses the third precoding matrix to precode the data transmitted between the second network device 120 and the terminal device 130. Correspondingly, the first network device 110 receives the eighth signaling. Furthermore, during subsequent data transmission, the first network device 110 may precode the data transmitted between the second network device 120 and the terminal device 130 using the third precoding matrix based on the eighth signaling.

In some embodiments, the seventh signaling and the eighth signaling may be the same signaling. That is, the second network device 120 indicates the third precoding matrix and instructs the first network device 110 to precode the data using the third precoding matrix in a single signaling. Thereby, signaling overhead can be reduced.

Example Implementation of Reflection Channel Estimation

In the following, a specific example will be used to describe how the terminal device 130 determines the estimation result of the reflected channel 124 based on the precoded first set of pilot signals and the precoded second set of pilot signals.

As described above with reference to FIG. 1 , the reflection channel 124 includes two segments of the channel, namely the channel 124 - 1 between the second network device 120 and the first network device 110 and the channel between the first network device 110 and the terminal device 130 124-2.

The location of the second network device 120 and the first network device 110 are usually deployed at a higher position from the ground. Therefore, in the airspace, the number of propagation paths in the channel 124 - 1 between the location of the second network device 120 and the first network device 110 is small, eg, the number of propagation paths and the number of antenna ports of the second network device 120 The ratio is below the threshold ratio. In addition, the location of the second network device 120 and the location of the first network device 110 are static. Therefore, in the time domain, the channel 124-1 is typically slowly varying, eg, the rate of change of channel strength with respect to time is below a threshold rate of change. In addition, the location of the second network device 120 and the location of the first network device 110 make the channel 124-1 less variable with respect to frequency in the frequency domain (corresponding to fewer propagation paths in the delay domain and less delay spread) . The above-mentioned characteristics of the channel 124-1 in the spatial, time and frequency domains make the channel 124-1 sparse in the spatial, time and frequency domains.

In some embodiments, in order to ensure that embodiments of the present disclosure are employed to determine the estimation result of the reflected channel when the channel 124-1 has the aforementioned sparsity, before transmitting the first set of pilot signals and the second set of pilot signals , the second network device 120 may send a third pilot signal (not shown) to the first network device 110 . After receiving the third pilot signal, the first network device 110 reflects the third pilot signal to the terminal device 130 . After receiving the third pilot signal, the terminal device 130 detects the power of the third pilot signal. If the terminal device 130 determines that the power is above the threshold power, it means that the channel 124-1 between the second network device 120 and the first network device 110 has the above-mentioned sparsity. Further, the terminal device 130 may send the indication information to the second network device 120 . The indication information instructs the second network device 120 to send the first set of pilot signals and the second set of pilot signals. Thus, the terminal device 130 can use the embodiments of the present disclosure to determine the estimation result of the reflected channel.

On the other hand, if the terminal device 130 determines that the power of the third pilot signal is below the threshold power, it means that the channel 124-1 between the second network device 120 and the first network device 110 does not have the above-mentioned sparsity. Further, the terminal device 130 may send additional indication information to the second network device 120 . The additional indication information indicates that the second network device 120 does not send the first set of pilot signals and the second set of pilot signals. Thus, the terminal device 130 can use the conventional scheme to determine the estimation result of the reflected channel.

In addition, end devices 130 are mobile and often in complex scattering environments. Therefore, the channel 124-2 between the first network device 110 and the terminal device 130 does not have sparsity in the space, time and frequency domains like the channel 124-1. For example, in the airspace, the number of propagation paths in the channel 124-2 between the first network device 110 and the terminal device 130 is relatively large; the channel 124-2 is usually time-varying, for example, the rate of change of the channel strength with respect to time is at a threshold and in the frequency domain, the channel 124-2 has a large change with respect to frequency (corresponding to a large number of propagation paths in the delay domain and a large delay spread).

Therefore, in some embodiments, terminal device 130 may determine the estimation result of reflected channel 124 in two stages using the above-described characteristics of channels 124-1 and 124-2, respectively. In other words, the terminal device 130 can divide the estimation process of the reflected channel 124 into the following two stages.

First-stage reflection channel estimation

In the first stage, the terminal device 130 may determine a first estimation result of the reflected channel 124 based on the precoded first set of pilot signals received from the first network device 110 . In the following, how the terminal device 130 determines the first estimation result of the reflected channel 124 will be described by way of a specific example.

表示第二网络设备120与第一网络设备110之间的信道124-1，

表示第一网络设备110与终端设备130之间的信道124-2，

表示第二网络设备120发送的第p个第一导频信号(p为正整数并且p∈[1,P])，

表示第一网络设备110对第p个导频信号的预编码向量，

表示第一网络设备110的第一预编码矩阵，则终端设备130在第一阶段接收到的信号

(其中

表示复数域)可以表示为：In this example, it is assumed that the second network device 120 is configured with M transmit ports (M is a positive integer), the first network device 110 is configured with N array elements (N is a positive integer), and the terminal device 130 is configured with 1 receiving port port. assumed

represents the channel 124-1 between the second network device 120 and the first network device 110,

represents the channel 124-2 between the first network device 110 and the terminal device 130,

represents the p-th first pilot signal sent by the second network device 120 (p is a positive integer and p∈[1,P]),

represents the precoding vector of the p-th pilot signal by the first network device 110,

represents the first precoding matrix of the first network device 110, the signal received by the terminal device 130 in the first stage

(in

represents the complex number field) can be expressed as:

表示复高斯白噪声，σ²表示噪声功率。in,

represents white complex Gaussian noise, and σ ² represents the noise power.

(其中vec表示向量化运算符，A、B和C表示矩阵)，式(1)可以等价表示为：According to the formula

(where vec represents a vectorization operator, and A, B, and C represent matrices), Equation (1) can be equivalently expressed as:

Assuming that the terminal device 130 has received a total of P precoded pilot signals (P is a positive integer), that is, the precoded first pilot signal set received by the terminal device 130 includes P pilot signals, then The encoded first set of pilot signals can be expressed as:

It should be appreciated that although the precoded first set of pilot signals is described in this example as including P precoded pilot signals, the scope of the present disclosure is not so limited. In other examples, the precoded first set of pilot signals may include more or fewer precoded pilot signals.

Since the number of propagation paths in the channel 124-1 between the second network device 120 and the first network device 110 is small, rank(F)≤min(M,N). Furthermore, since rank(AB)≤min(rank(A),rank(B)), rank(diag(h)F)≤min(M,N). Thus, the equivalent channel vector vec(diag(h)F) of the reflection channel 124 can be decomposed into vec(diag(h)F)=As _x , where As represents the spatial basis and _x represents the projection coefficient. In the compressed sensing theory, the spatial domain basis is also called a perception matrix, for example, it can be an oversampled discrete Fourier transform (DFT) matrix, and the like. Furthermore, since diag(h)F is a low-rank matrix, x is a sparse vector, as shown in Figure 5.

If D is defined as follows:

Then formula (3) can be equivalently expressed as:

y=DAs _x +n (5)

FIG. 5 schematically shows the transformation process of the precoded first pilot signal set y from the above formula (3) to the above formula (5) based on the above-mentioned compressed sensing theory. According to equation (3) above, the precoded first set of pilot signals y 510 can be represented as a product of matrix D 520 and an equivalent channel vector vec(diag(h)F) 530 . For simplicity of description, the matrix n representing noise is not shown in FIG. 5 . According to the above description, based on the compressed sensing theory, the equivalent channel vector vec(diag(h)F) of the reflection channel 124 in the above formula (3) can be decomposed into the _projection on the spatial base As ₅₄₀ and the spatial base As Product of coefficients x 550.

Since x is a sparse vector, estimating x given y, D, and A _s can be regarded as a standard sparse signal reconstruction problem, so for example, classical algorithms such as Orthogonal Matching Pursuit (OMP) can be used to solve it. According to the compressed sensing theory, the smaller the column correlation of the DA _s matrix, the higher the estimation accuracy of x. The column correlation of a matrix refers to the largest value after taking the inner product modulo between any two columns of the matrix. Therefore, the first precoding matrix (ie, θ ₁ , . . . θ _P ) can be designed to minimize the column correlation of the DA _s matrix.

It should be pointed out that, according to the above formula (4) and the above formula (5), the design of the first precoding matrix only depends on the spatial base _As and the pilot signal W _{p sp} . Therefore, the first precoding matrix can be designed in advance without the need for the second network device 120 to inform the first network device 110 . Therefore, when the second network device 120 notifies the first network device 110 to perform the first-stage channel estimation, the first network device 110 can directly configure the first precoding matrix. For example, as described above with reference to FIG. 4 , the first precoding matrix may be pre-stored in the controller 240 as shown in FIG. 2 . The second network device 120 may send a third signaling to the first network device 110 to notify the first network device 110 to precode the first set of pilot signals using the preconfigured first precoding matrix. Since the first precoding matrix is pre-configured, there is no need for the second network device 120 to send signaling for indicating the first precoding matrix to the first network device 110, so signaling overhead can be reduced.

After receiving the third signaling, the first network device 110 configures the first precoding matrix. Then, the second network device 120 may send the first set of pilot signals to the first network device 110 . Further, the first network device 110 precodes the first set of pilot signals using the first precoding matrix, and sends the precoded first set of pilot signals to the terminal device 130 . Then, the terminal device 130 may perform the first-stage channel estimation based on the above equation (5). In some embodiments, the terminal device 130 may use a classical algorithm such as OMP to recover the projection coefficient _x on the spatial base As. Then, the terminal device 130 may reconstruct the first estimation result diag(h)F of the reflected channel 124 based on vec(diag(h)F)=As _x . Further, the terminal device 130 may send information (ie, first information) related to the first estimation result diag(h)F of the reflected channel 124 to the second network device 120 . For example, the terminal device 130 may transmit to the second network device 120 at least one of amplitude information and phase information of each element in diag(h)F.

In this paper, diag(h)F is also referred to as the first channel matrix. From the above description, the dimension of the first channel matrix is N×M, where N is the number of sending ports or receiving ports of the first network device 110 , and M is the number of sending ports of the second network device 120 .

It should be understood that the process of determining the first estimation result of the reflected channel 124 is described above by taking the terminal device 130 configured with one receiving port as an example. In the case where the terminal device 130 is configured with multiple receiving ports, a similar process may be used to determine the first estimation result of the reflected channel 124, and thus will not be repeated here. It should also be understood that the above description is only one specific example of the process of determining the first estimation result of the reflected channel 124 . The terminal device 130 may use other methods currently known or developed in the future to determine the first estimation result of the reflected channel 124 .

Second-stage reflection channel estimation

In the second stage, terminal device 130 may determine a second estimation result for channel 124 - 2 based on the precoded second set of pilot signals received from first network device 110 and the first estimation result for reflected channel 124 . Further, the second network device 120 may be based on the information received from the terminal device 130 about the first estimation result of the reflected channel 124 (ie the first information) and the information about the second estimation result of the channel 124-2 (ie the first information) 2 information) to determine the final estimation result of the reflected channel 124. . In the following, how the terminal device 130 determines the second estimation result of the channel 124-2 is described still in conjunction with the specific example described in the first stage.

As mentioned above, since the terminal device 130 is mobile and usually in a complex scattering environment, the channel 124-2 between the first network device 110 and the terminal device 130 has a large number of propagation paths in the air domain and the frequency domain. and is usually time-varying. Therefore, in the second stage, the method of the reflection channel estimation in the first stage cannot be used. However, since the channel 124-1 between the second network device 120 and the first network device 110 is usually slowly varying, the time-varying reflection channel 124 can be represented as follows:

表示时变的反射信道124-2相对于信道124-1的增量部分(即待确定的信道124-2的第二估计结果)。由此可知，在第二阶段中仅需估计Δ_t即可。where G _t represents the final estimation result of the reflection channel 124 to be determined, diag(h ^H )F represents the first estimation result of the reflection channel 124 that has been determined in the first stage,

Represents the incremental portion of the time-varying reflected channel 124-2 relative to the channel 124-1 (ie, the second estimate of the channel 124-2 to be determined). It can be seen from this that only _Δt needs to be estimated in the second stage.

也被称作第二信道矩阵。通过以上描述可知，第二信道矩阵为对角矩阵，并且维度为N×N。反射信道124的最终估计结果Gt也被称作第三信道矩阵，其维度为N×M。in the text,

Also referred to as the second channel matrix. It can be known from the above description that the second channel matrix is a diagonal matrix and has a dimension of N×N. The final estimation result Gt of the reflection channel 124 is also called a third channel matrix, and its dimension is N×M.

It should be understood that diag(h ^H )F in the above formula (6) is a modification of the first estimation result diag(h)F described above. In some embodiments, diag(h ^H )F in the above formula (6) can also be replaced by diag(h)F.

可以表示为：Following the parameters described in the first stage, the signal received by the terminal device 130 in the second stage

It can be expressed as:

次经预编码的导频信号，即终端设备130接收到的经预编码的第二导频信号集合包括

个导频信号，则经预编码的第二导频信号集合可以表示为Assume that the terminal device 130 receives a total of

The second precoded pilot signal, ie the second set of precoded pilot signals received by the terminal device 130 includes

pilot signals, the precoded second set of pilot signals can be expressed as

表示第一网络设备110的第二预编码矩阵，

表示第二网络设备120发送的第p个第二导频信号(p为正整数并且

)。在给定Λ和

的情况下估计Δ_t是经典的信号检测问题，因而终端设备130可以采用例如最小二乘法、最小均方误差法等算法对Δ_t进行求解。in

represents the second precoding matrix of the first network device 110,

represents the p-th second pilot signal sent by the second network device 120 (p is a positive integer and

). at a given Λ and

Estimating Δ _t in the case of , is a classic signal detection problem, so the terminal device 130 can solve Δ _t using algorithms such as the least squares method, the least mean square error method, and the like.

有关的信息(即第二信息)。例如，终端设备130可以向第二网络设备120发送

的对角线元素的幅值信息和相位信息中的至少一项。进而，第二网络设备120可以基于从终端设备130接收的第一信息和第二信息，确定反射信道124的最终估计结果G_t。例如，第二网络设备120可以基于上式(6)重构出反射信道124的最终估计结果G_t。After solving for _Δt , the terminal device 130 may send the second estimation result of the channel 124-2 to the second network device 120

related information (ie, second information). For example, the terminal device 130 may send to the second network device 120

At least one of amplitude information and phase information of the diagonal elements of . Further, the second network device 120 may determine the final estimation result G _t of the reflected channel 124 based on the first information and the second information received from the terminal device 130 . For example, the second network device 120 may reconstruct the final estimation result G _t of the reflected channel 124 based on the above formula (6).

个经预编码的导频信号，但是本公开的范围并不局限于此。在其他示例中，经预编码的第二导频信号集合可以包括更多或更少的经预编码的导频信号。It should be appreciated that although the precoded second set of pilot signals is described in this example as comprising

precoded pilot signals, but the scope of the present disclosure is not so limited. In other examples, the precoded second set of pilot signals may include more or fewer precoded pilot signals.

It should also be understood that the least squares method and the least mean squared error method described above are only examples, and the terminal device 130 may solve for _Δt by any algorithm currently known or developed in the future, and the scope of the present disclosure is not limited in this respect. limit.

)设计为使得Λ尽可能接近单位阵，即However, the above algorithms all have the problem of noise amplification. To solve this problem, the second precoding matrix (ie

) is designed to make Λ as close as possible to the identity matrix, i.e.

It should be noted that the design of the second precoding matrix only depends on the pilot signal and the modified form diag(h ^H )F of the first estimation result of the reflected channel 124 determined in the first stage. Since diag(h ^H )F changes slowly again, after the terminal device 130 determines the second precoding matrix, it does not need to notify the second network device 120 frequently, and only needs to notify the second network device 120 at a longer period. For example, the terminal device 130 may notify the second network device 120 of the second precoding matrix at a cycle of several hundreds of milliseconds. It should be understood that the period of several hundred milliseconds is merely an example and is not intended to suggest any limitation. According to actual needs or configurations, the terminal device 130 may notify the second precoding matrix with a period of any suitable length.

It should be understood that the determination of the final estimation result of the reflected channel 124 in two stages is described in the above example implementation. However, the scope of the present disclosure is not limited thereto. In some other implementations, such as in embodiments where the second precoding matrix and the first precoding matrix are the same, the terminal device 130 may receive the precoded first set of pilot signals and the precoded second The reflection channel 124 is collectively estimated after the pilot signal set.

Example implementation of the data transfer phase

之后，终端设备130可以向第二网络设备120发送与信道124-2的第二估计结果

有关的信息(即第二信息)。进而，第二网络设备120可以基于从终端设备130接收的第一信息和第二信息，确定反射信道124的最终估计结果G_t。As described above, after the first estimation result diag(h)F of the reflected channel 124 is determined, information related to the first estimation result diag(h)F of the reflected channel 124 may be sent to the second network device 120 (ie, first information). After determining the second estimation result of the channel 124-2

Afterwards, the terminal device 130 may send the second estimation result of the channel 124-2 to the second network device 120

related information (ie, second information). Further, the second network device 120 may determine the final estimation result G _t of the reflected channel 124 based on the first information and the second information received from the terminal device 130 .

In the embodiment in which the second network device 120 serves multiple terminal devices, each terminal device may send the estimation result of its reflected channel and the estimation of the channel between the first network device and the terminal device to the second network device 120 result. Further, the second network device 120 may jointly optimize the precoding matrix used by the first network device 110 to precode the data transmitted between the second network device 120 and the corresponding terminal device according to the estimation results sent by the respective terminal devices , and a precoding matrix used by the second network device 120 to precode the data. Hereinafter, description will be given by way of specific examples.

In this example, assuming that the second network device 120 serves a total of K user equipments (K is a positive integer), the joint optimization problem can be expressed as:

表示数据传输阶段由第二网络设备120使用的预编码矩阵，P_max表示数据传输阶段第二网络设备120的最大发射功率，而γ_k表示第k个用户设备的信干噪比，即：where θ represents the precoding matrix used by the first network device 110 in the data transmission stage, η represents the reflection efficiency of the array element of the first network device 110,

represents the precoding matrix used by the second network device 120 in the data transmission phase, _Pmax represents the maximum transmit power of the second network device 120 in the data transmission phase, and _γk represents the signal-to-interference-noise ratio of the kth user equipment, namely:

表示数据传输阶段第k个用户设备段的噪声能量，

表示第二网络设备120与第k个用户设备之间的直传信道。该直传信道可以通过目前已知的信道估计方案来获得，因而不再赘述。in

represents the noise energy of the kth user equipment segment in the data transmission stage,

Indicates the direct transmission channel between the second network device 120 and the kth user equipment. The direct transmission channel can be obtained by a currently known channel estimation scheme, and thus will not be repeated here.

可以将由式(10)表示的优化问题转换为以下优化问题：The optimization problem represented by equation (10) can be solved in a variety of ways, and an example solution method will be described below. Specifically, by introducing auxiliary optimization variables

The optimization problem represented by equation (10) can be transformed into the following optimization problem:

和θ给定时，α_k最优取值为γ_k。当

给定时，由式(12)表示的优化问题P1等价为以下优化问题：when

When and θ are given, the optimal value of α _k is γ _k . when

When given, the optimization problem P1 expressed by Eq. (12) is equivalent to the following optimization problem:

可以定义等效信道

并利用分数规划算法，由式(13)表示的优化问题P2可转换为以下优化问题：First, solve by fixing Θ

Equivalent channel can be defined

And using the fractional programming algorithm, the optimization problem P2 represented by equation (13) can be transformed into the following optimization problem:

将由式(14)表示的优化问题P3中的目标函数关于β_k求偏导，并令其等于0可得：if given

Taking the partial derivative of the objective function in the optimization problem P3 expressed by Eq. (14) with respect to β _k and making it equal to 0, we can obtain:

则利用拉格朗日乘子法可得：if given

Then, using the Lagrange multiplier method, we can get:

The optimal Lagrangian multiplier λ can be obtained by binary search.

来求解Θ。可以定义辅助变量

θ＝[θ₁,θ₂,…,θ_N]^T＝diag(Θ)，并利用分数规划算法，将由式(14)表示的优化问题P3转换为以下优化问题：Then, by fixing

to solve Θ. Auxiliary variables can be defined

θ=[θ ₁ ,θ ₂ ,...,θ _N ] ^T =diag(Θ), and using the fractional programming algorithm, the optimization problem P3 represented by equation (14) is transformed into the following optimization problem:

If Θ is given, take the partial derivative of the objective function in the optimization problem P4 expressed by Eq. (18) with respect to β _k and set it equal to 0 to obtain:

将其值代入式(18)，并定义辅助变量

和

则由式(18)表示的优化问题P4等价为：if given

Substitute its value into equation (18) and define auxiliary variables

and

Then the optimization problem P4 expressed by equation (18) is equivalent to:

相位在[0,2π]随机均匀分布)，可通过下述迭代方式更新θ：The above problem P5 can be solved iteratively by an optimization minimization (Majorization-Minimization) method, that is, given an initial θ (for example, the magnitude of θ is fixed as

The phase is randomly and uniformly distributed at [0,2π]), and θ can be updated iteratively as follows:

q ^t =(λ _max IU)θ ^t +v (21)

where _λmax is the largest eigenvalue of U.

After optimizing the precoding matrix to be used by the second network device 120 and the precoding matrix to be used by the first network device 110, the second network device 120 informs the first network device 110 of the precoding matrix used by the first network device 110 . After that, the second network device 120 sends the downlink data, which is reflected by the first network device 110 and then reaches the terminal device 130 to complete the downlink data transmission.

It should be understood that the algorithms for determining the precoding matrix used by the first network device 110 and the precoding matrix used by the second network device 120 described in the above example implementations are merely examples. The second network device 120 or the terminal device 130 may use other methods currently known or developed in the future to determine the above-mentioned precoding matrix based on the final estimation result of the feedback channel 124 .

FIG. 6 shows a flowchart of an example method 600 for channel estimation according to an embodiment of the present disclosure. In some embodiments, example method 600 may be implemented by terminal device 130 in example MIMO system 100, eg, by a processor or processing unit of terminal device 130 in conjunction with other components (eg, transceivers). In other embodiments, the example method 600 may also be implemented by other communication devices independent of the example MIMO system 100 . For ease of illustration, the example method 600 will be described with reference to FIG. 1 .

At block 610 , the terminal device 130 determines a first estimation result of the first channel from the second network device 120 to the terminal device 130 via the first network device 110 based on the first set of pilot signals received from the first network device 110 . At block 620 , the terminal device 130 sends first information related to the first estimation result to the second network device 120 . At block 630, the terminal device 130 determines a second estimation result of the second channel between the first network device 110 and the terminal device 130 based on the second set of pilot signals received from the first network device 110 and the first estimation result . At block 640 , the terminal device 130 sends second information related to the second estimation result to the second network device 120 . The example method 600 can reduce the overhead of pilot signals and the delay of reflected channel estimation.

In some embodiments, the first estimation result includes a first channel matrix, the second estimation result includes a second channel matrix, the third estimation result of the first channel includes a third channel matrix, and the third channel matrix=second channel matrix× The first channel matrix.

In some embodiments, the dimension of the first channel matrix is N×M, where N is the number of transmit ports or receive ports of the first network device 110 , M is the number of transmit ports of the second network device 120 , and the second channel The dimension of the matrix is NxN and is a diagonal matrix, and the dimension of the third channel matrix is NxM.

In some embodiments, the method 600 further comprises: the terminal device 130 receiving a first signaling from the second network device 120, the first signaling indicating the content of the first information to be sent by the terminal device 130 to the second network device 120; and The terminal device 130 sends the first information to the second network device 120 based on the first signaling.

In some embodiments, the first signaling further indicates the content of the second information to be sent by the terminal device 130 to the second network device 120 . The method 600 further includes: the terminal device 130 sends the second information to the second network device 120 based on the first signaling.

In some embodiments, the method 600 further comprises: the terminal device 130 receiving a second signaling from the second network device 120, the second signaling indicating the content of the second information to be sent by the terminal device 130 to the second network device 120; and The terminal device 130 sends the second information to the second network device 120 based on the second signaling.

In some embodiments, the content of the first information includes at least one of the following: amplitude information of each element in the first channel matrix, phase information of each element in the first channel matrix, and Multipath number information, multipath incident angle information, multipath exit angle information, multipath time delay information, multipath Doppler frequency shift information, and multipath gain information.

In some embodiments, the content of the second information includes at least one of amplitude information and phase information of diagonal elements of the second channel matrix.

In some embodiments, the third precoding matrix and the fourth precoding matrix are determined based on the first information and the second information, and the third precoding matrix is used by the first network device 110 to provide information between the second network device 120 and the terminal. The data transmitted between the devices 130 is precoded, and the fourth precoding matrix is used by the second network device 120 to precode the data.

In some embodiments, the method 600 further includes: before receiving the first set of pilot signals and the second set of pilot signals, the terminal device 130 receives a third pilot signal from the first network device 110; the terminal device 130 detects the third the power of the pilot signal; and if the terminal device 130 determines that the power is above the threshold power, the terminal device 130 sends indication information to the second network device 120 that instructs the second network device 120 to send the first set of pilot signals and the second pilot signal collection of frequency signals.

7 shows a flow diagram of an example method 700 for channel estimation in accordance with an embodiment of the present disclosure. In some embodiments, the example method 700 may be implemented by the second network device 120 in the example MIMO system 100, for example, by a processor or processing unit of the second network device 120 in conjunction with other components (eg, transceivers) . In other embodiments, the example method 700 may also be implemented by other communication devices independent of the example MIMO system 100 . For ease of illustration, the example method 700 will be described with reference to FIG. 1 .

At block 710 , the second network device 120 sends the first set of pilot signals to the first network device 110 . At block 720 , the second network device 120 receives the first information from the terminal device 130 . The first information relates to a first estimation result of the first channel from the second network device 120 via the first network device 110 to the terminal device 130 . The first estimation result is determined based on the first set of pilot signals. At block 730 , the second network device 120 sends a second set of pilot signals to the first network device 110 . At block 740 , the second network device 120 receives second information from the terminal device 130 . The second information relates to a second estimation result of the second channel between the first network device 110 and the terminal device 130, the second estimation result being determined based on the second set of pilot signals. The example method 700 can reduce the overhead of pilot signals and the delay of reflected channel estimation.

In some embodiments, the first estimation result includes a first channel matrix, the second estimation result includes a second channel matrix, the third estimation result of the first channel includes a third channel matrix, and the third channel matrix=second channel matrix× The first channel matrix.

In some embodiments, the dimension of the first channel matrix is N×M, where N is the number of transmit ports or receive ports of the first network device 110 , M is the number of transmit ports of the second network device 120 , and the second channel The dimension of the matrix is NxN and is a diagonal matrix, and the dimension of the third channel matrix is NxM.

In some embodiments, the method 700 further includes: the second network device 120 sends a first signaling to the terminal device 130, the first signaling indicates the content of the first information to be sent to the second network device 120 by the terminal device 130, the first signaling A message is sent based on the first signaling.

In some embodiments, the first signaling further indicates the content of the second information to be sent by the terminal device 130 to the second network device 120, the second information being sent based on the first signaling.

In some embodiments, the method 700 further includes: the second network device 120 sends a second signaling to the terminal device 130, the second signaling indicates the content of the second information to be sent to the second network device 120 by the terminal device 130, the first The second information is sent based on the second signaling.

In some embodiments, the content of the first information includes at least one of the following: amplitude information of each element in the first channel matrix, phase information of each element in the first channel matrix, and Multipath number information, multipath incident angle information, multipath exit angle information, multipath time delay information, multipath Doppler frequency shift information, and multipath gain information.

In some embodiments, the content of the second information includes at least one of amplitude information and phase information of diagonal elements of the second channel matrix.

In some embodiments, the method 700 further includes: the second network device 120 sends a third signaling to the first network device 110, so that the first network device 110 uses a preconfigured first precoding matrix pair based on the third signaling The first set of pilot signals is precoded.

In some embodiments, the method 700 further includes: the second network device 120 sends a fourth signaling to the first network device 110, so that the first network device 110 uses the first precoding matrix to perform the second signaling based on the fourth signaling. The set of frequency signals is precoded.

In some embodiments, the method 700 further includes: the second network device 120 receives the first information from the terminal device 130 and determines the second precoding matrix; the second network device 120 sends an indication of the second precoding matrix to the first network device 110 and the second network device 120 sends the sixth signaling to the first network device 110, so that the first network device 110 uses the second precoding matrix to perform the second pilot signal set precoding.

In some embodiments, the method 700 further includes: the second network device 120 determining a third precoding matrix and a fourth precoding matrix based on the first information and the second information, the third precoding matrix being used by the first network device 110 In order to precode the data transmitted between the second network device 120 and the terminal device 130, the fourth precoding matrix is used by the second network device 120 to precode the data.

In some embodiments, the method 700 further comprises: the second network device 120 sending seventh signaling to the first network device 110 indicating the third precoding matrix; and the second network device 120 sending the eighth signaling to the first network device 110 signaling, so that the first network device 110 uses the third precoding matrix to precode the data based on the eighth signaling.

In some embodiments, the method 700 further comprises: before transmitting the first set of pilot signals and the second set of pilot signals, the second network device 120 sending a third pilot signal to the first network device 110; and from the terminal device 130 receives indication information, the indication information instructs the second network device 120 to send the first set of pilot signals and the second set of pilot signals, and the indication information is used in response to the terminal device 130 detecting that the power of the third pilot signal is above the threshold power. send.

8 shows a flow diagram of an example method 800 for channel estimation in accordance with an embodiment of the present disclosure. In some embodiments, the example method 800 may be implemented by the first network device 110 in the example MIMO system 100, for example, by a processor or processing unit of the first network device 110 in conjunction with other components (eg, transceivers) . In other embodiments, the example method 800 may also be implemented by other communication devices independent of the example MIMO system 100 . For ease of illustration, the example method 800 will be described with reference to FIG. 1 .

At block 810 , the first network device 110 receives a first set of pilot signals from the second network device 120 . At block 820 , the first network device 110 receives a second set of pilot signals from the second network device 120 . At block 830 , the first network device 110 transmits the first set of pilot signals and the second set of pilot signals to the terminal device 130 .

In some embodiments, the method 800 further includes: the first network device 110 receives third signaling from the second network device 120; the first network device 110 uses the preconfigured first precoding matrix to A set of pilot signals is precoded; and the first network device 110 sends the precoded first set of pilot signals to the terminal device 130 .

In some embodiments, the method 800 further includes: the first network device 110 receives fourth signaling from the second network device 120; The set of signals is precoded; and the first network device 110 sends the precoded second set of pilot signals to the terminal device 130 .

In some embodiments, the method 800 further comprises: the first network device 110 receiving fifth signaling from the second network device 120 indicating a second precoding matrix, the second precoding matrix being determined based on the first information, the first information Related to the first estimation result of the first channel from the second network device 120 to the terminal device 130 via the first network device 110, the first estimation result is determined based on the first set of pilot signals; The network device 120 receives the sixth signaling; the first network device 110 uses the second precoding matrix to precode the second pilot signal set based on the sixth signaling; A set of encoded second pilot signals.

In some embodiments, the method 800 further includes the first network device 110 receiving from the second network device 120 seventh signaling indicative of a third precoding matrix determined based on the first information and the second information , the first information is related to the first estimation result of the first channel from the second network device 120 to the terminal device 130 via the first network device 110, the first estimation result is determined based on the first set of pilot signals, and the second information is related to The second estimation result of the second channel between the first network device 110 and the terminal device 130 is related, and the second estimation result is determined based on the second pilot signal set and the first estimation result; the first network device 110 receives data from the second network The device 120 receives the eighth signaling; and the first network device 110 precodes the data transmitted between the second network device 120 and the terminal device 130 using the third precoding matrix based on the eighth signaling.

9 shows a block diagram of an example electronic device 900 according to an embodiment of the present disclosure. The example electronic device 900 may be used to implement communication devices, such as the network devices 110 and 120 and the terminal device 130 in FIG. 1 , and the like. Accordingly, example electronic device 900 may also be referred to as example communication device 900 herein. As shown in FIG. 9 , an example communication device 900 may include a processor 910 and a memory 920 coupled to the processor 910 . Computer program instructions 925 are stored in memory 920 . Additionally, the example communication device 900 can also include a communication module 930 coupled to the processor 910 . The communication module 930 may be used for two-way communication, and may have at least one cable, fiber optic cable, wireless interface, etc., for facilitating communication. A communication interface can represent any interface used to communicate with other devices.

Processor 910 may be of any type suitable for the local technical environment, and may include, by way of non-limiting example, one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs), and multicore-based processors architecture of the processor. The example communication device 900 may have multiple processors, such as application specific integrated circuit chips that are slaved in time with a clock that is synchronized with the master processor. Memory 920 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memory include, but are not limited to, read only memory (ROM), electrically erasable programmable read only memory (EPROM), flash memory, hard disks, compact disks (CDs), digital versatile disks (DVDs), and Other magnetic storage devices and/or optical storage devices. Examples of volatile memory include, but are not limited to, random memory access memory (RAM) or other volatile memory that does not persist during power down. Computer program instructions 925 may include computer-executable instructions executable by the associated processor 910 . In some embodiments, computer program instructions 925 may be stored in ROM of memory 920 . The processor 910 may perform various suitable actions and processes by loading the memory 920 into the RAM of the memory 920 . Embodiments of the present disclosure may be implemented by computer program instructions 925 to cause the example communication device 900 to perform any method or process of the present disclosure as discussed above with reference to Figures 4 and 6-8. Of course, the embodiments of the present disclosure can also be implemented by hardware or a combination of software and hardware.

In some embodiments, the computer program instructions 925 may be tangibly embodied on a computer readable medium. Such computer-readable media may be included in example communication device 900 (eg, memory 920 ) or in other storage devices accessible by example communication device 900 . The example communication device 900 may read computer program instructions 925 from a computer-readable medium to the RAM of the memory 920 for execution. Computer-readable media may include various tangible non-volatile storage devices such as ROM, EPROM, flash memory, hard disks, CDs, DVDs, and the like.

In general, the various example embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic, or any combination thereof. Certain aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor or other computing device. For example, in some embodiments, various examples of the present disclosure (eg, methods, apparatus, or devices) may be implemented in part or in whole on a computer-readable medium. While aspects of the embodiments of the present disclosure are illustrated or described as block diagrams, flowcharts, or using some other graphical representation, it is to be understood that the blocks, apparatus, systems, techniques, or methods described herein may be taken as non-limiting Examples are implemented in hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controllers or other computing devices, or some combination thereof.

The present disclosure also provides at least one computer program product stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions, such as program modules included in a device executed on a target's physical or virtual processor, to perform the examples described above with respect to FIGS. 4 and 6-8 Methods or example processes 400 , 600 , 700 and 800 . Generally, program modules may include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data structures. In various embodiments, the functionality of the program modules may be combined or divided among the described program modules. Computer-executable instructions for program modules may be executed in local or distributed devices. In a distributed facility, program modules may be located in both local and remote storage media.

Program code for implementing the methods of the present disclosure may be written in one or more programming languages. Such computer program code may be provided to a processor of a general purpose computer, special purpose computer or other programmable data processing apparatus, such that the program code, when executed by the computer or other programmable data processing apparatus, causes the flowcharts and/or block diagrams The functions/operations specified in are implemented. The program code may execute entirely on the computer, partly on the computer, as a stand-alone software package, partly on the computer and partly on a remote computer or entirely on the remote computer or server. In the context of the present disclosure, computer program code or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform the various processes and operations described above. Examples of carriers include signals, computer-readable media, and the like.

The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. Computer-readable media may include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or devices, or any suitable combination thereof. More detailed examples of machine-readable storage media include electrical connections with one or more wires, portable computer disks, hard disks, random access memory (RAM), read only memory (ROM), erasable programmable read only Memory (EPROM or flash memory), fiber optics, portable compact disk read only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

Additionally, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in a sequential order, or that all illustrated operations be performed to obtain desired results. In some cases, multitasking or parallel processing can be beneficial. Likewise, although the above discussion contains certain specific implementation details, these should not be construed as limiting the scope of any invention or claims, but rather as descriptions of particular embodiments that may be directed to particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims (35)

1. A method for acquiring channel information, comprising: The terminal device determines, based on the first set of pilot signals received from the first network device, a first estimation result of the first channel from the second network device to the terminal device via the first network device; sending, by the terminal device, first information related to the first estimation result to the second network device; the terminal device determines a second estimate of a second channel between the first network device and the terminal device based on the second set of pilot signals received from the first network device and the first estimation result results; and The terminal device sends second information related to the second estimation result to the second network device. 2. The method of claim 1, wherein the first estimation result comprises a first channel matrix, the second estimation result comprises a second channel matrix, and the third estimation result of the first channel comprises a third channel matrix, the third channel matrix=the second channel matrix×the first channel matrix. 3. The method according to claim 2, wherein the dimension of the first channel matrix is N×M, where N is the number of transmit ports or receive ports of the first network device, and M is the second network The number of transmission ports of the device, the dimension of the second channel matrix is N×N and is a diagonal matrix, and the dimension of the third channel matrix is N×M. 4. The method of any one of claims 1-3, further comprising: the terminal device receives first signaling from the second network device, the first signaling indicating the content of the first information to be sent by the terminal device to the second network device; and The terminal device sends the first information to the second network device based on the first signaling. 5. The method according to claim 4, wherein the first signaling further indicates the content of the second information to be sent by the terminal device to the second network device; The method further includes: The terminal device sends the second information to the second network device based on the first signaling. 6. The method of any one of claims 1-4, further comprising: the terminal device receives second signaling from the second network device, the second signaling indicating the content of the second information to be sent by the terminal device to the second network device; and The terminal device sends the second information to the second network device based on the second signaling. 7. The method of claim 4, wherein the content of the first information comprises at least one of the following: amplitude information of each element in the first channel matrix, the phase information of each element in the first channel matrix, information on the number of multipaths of the first channel, the incident angle information of the multipath, the exit angle information of the multipath, the multipath delay information, the Doppler shift information of the multipath, Gain information of the multipath. 8. The method of claim 5 or 6, wherein the content of the second information includes at least one of amplitude information and phase information of diagonal elements of the second channel matrix. 9. The method of any of claims 1-8, wherein a third precoding matrix and a fourth precoding matrix are determined based on the first information and the second information, the third precoding matrix A coding matrix is used by the first network device to precode data transmitted between the second network device and the terminal device, and the fourth precoding matrix is used by the second network device to The data is precoded. 10. The method of any one of claims 1-9, further comprising: before receiving the first set of pilot signals and the second set of pilot signals, the terminal device receives a third pilot signal from the first network device; the terminal device detects the power of the third pilot signal; and If the terminal device determines that the power is above a threshold power, the terminal device sends indication information to the second network device, where the indication information instructs the second network device to send the first pilot signal set and the second set of pilot signals. 11. A method for acquiring channel information, comprising: The second network device sends the first set of pilot signals to the first network device; the second network device receives first information from a terminal device, the first information being related to a first estimation result of a first channel from the second network device via the first network device to the terminal device, the first estimation result is determined based on the first set of pilot signals; sending, by the second network device, a second set of pilot signals to the first network device; and The second network device receives second information from the terminal device, the second information is related to a second estimation result of a second channel between the first network device and the terminal device, the second The estimation result is determined based on the second set of pilot signals. 12. The method of claim 11, wherein the first estimation result includes a first channel matrix, the second estimation result includes a second channel matrix, and the third estimation result for the first channel includes a third channel matrix, the third channel matrix=the second channel matrix×the first channel matrix. 13. The method of claim 12, wherein the dimension of the first channel matrix is N×M, where N is the number of transmit ports or receive ports of the first network device, and M is the second network The number of transmission ports of the device, the dimension of the second channel matrix is N×N and is a diagonal matrix, and the dimension of the third channel matrix is N×M. 14. The method of any of claims 11-13, further comprising: The second network device sends first signaling to the terminal device, where the first signaling indicates the content of the first information to be sent by the terminal device to the second network device, the first signaling Information is sent based on the first signaling. 15. The method of claim 14, wherein the first signaling further indicates the content of the second information to be sent by the terminal device to the second network device, the second information based on the The first signaling is sent. 16. The method of any of claims 11-14, further comprising: The second network device sends a second signaling to the terminal device, the second signaling indicates the content of the second information to be sent by the terminal device to the second network device, the second Information is sent based on the second signaling. 17. The method of claim 14, wherein the content of the first information comprises at least one of the following: amplitude information of each element in the first channel matrix, the phase information of each element in the first channel matrix, information on the number of multipaths of the first channel, the incident angle information of the multipath, the exit angle information of the multipath, the multipath delay information, the Doppler shift information of the multipath, Gain information of the multipath. 18. The method of claim 15 or 16, wherein the content of the second information includes at least one of magnitude information and phase information of diagonal elements of the second channel matrix. 19. The method of any one of claims 11-18, further comprising: The second network device sends a third signaling to the first network device, so that the first network device uses a preconfigured first precoding matrix for the first pilot based on the third signaling The set of signals is precoded. 20. The method of claim 19, further comprising: Sending, by the second network device, fourth signaling to the first network device, so that the first network device uses the first precoding matrix for the second pilot signal based on the fourth signaling set for precoding. 21. The method of any one of claims 11-19, further comprising: The second network device receives the first information from the terminal device, and determines a second precoding matrix; sending, by the second network device, fifth signaling indicating the second precoding matrix to the first network device; and Sending, by the second network device, sixth signaling to the first network device, so that the first network device uses the second precoding matrix for the second pilot signal based on the sixth signaling set for precoding. 22. The method of any one of claims 11-21, further comprising: The second network device determines a third precoding matrix and a fourth precoding matrix based on the first information and the second information, and the third precoding matrix is used by the first network device to The data transmitted between the second network device and the terminal device is precoded, and the fourth precoding matrix is used by the second network device to precode the data. 23. The method of claim 22, further comprising: sending, by the second network device, seventh signaling indicating the third precoding matrix to the first network device; and The second network device sends an eighth signaling to the first network device, so that the first network device uses the third precoding matrix to precode the data based on the eighth signaling. 24. The method of any one of claims 11-23, further comprising: The second network device sends a third pilot signal to the first network device before sending the first set of pilot signals and the second set of pilot signals; and Receive indication information from the terminal device, the indication information instructing the second network device to send the first set of pilot signals and the second set of pilot signals, the indication information is in response to the terminal device detecting The power to the third pilot signal is above a threshold power and is transmitted. 25. A method for acquiring channel information, comprising: the first network device receives the first set of pilot signals from the second network device; the first network device receives a second set of pilot signals from the second network device; and The first network device sends the first pilot signal set and the second pilot signal set to the terminal device. 26. The method of claim 25, further comprising: receiving, by the first network device, third signaling from the second network device; The first network device precodes the first set of pilot signals using a preconfigured first precoding matrix based on the third signaling; and The first network device sends the precoded first set of pilot signals to the terminal device. 27. The method of claim 26, further comprising: receiving, by the first network device, fourth signaling from the second network device; the first network device precoding the second set of pilot signals using the first precoding matrix based on the fourth signaling; and The first network device sends the precoded second set of pilot signals to the terminal device. 28. The method of claim 25 or 26, further comprising: The first network device receives fifth signaling from the second network device indicating a second precoding matrix, the second precoding matrix is determined based on first information, the first information and the Two network devices are related to a first estimation result of a first channel that reaches the terminal device via the first network device, and the first estimation result is determined based on the first pilot signal set; receiving, by the first network device, sixth signaling from the second network device; the first network device precoding the second set of pilot signals using the second precoding matrix based on the sixth signaling; and The first network device sends the precoded second set of pilot signals to the terminal device. 29. The method of any one of claims 25 to 28, further comprising: The first network device receives seventh signaling indicating a third precoding matrix from the second network device, the third precoding matrix is determined based on the first information and the second information, the first information and the related to a first estimation result of a first channel from the second network device to the terminal device via the first network device, the first estimation result being determined based on the first set of pilot signals, the The second information is related to a second estimation result of the second channel between the first network device and the terminal device, the second estimation result is based on the second pilot signal set and the first estimation result It is determined; the first network device receives eighth signaling from the second network device; and The first network device uses the third precoding matrix to precode the data transmitted between the second network device and the terminal device based on the eighth signaling. 30. A terminal device, comprising: processor; and A memory storing computer program instructions, the memory and the computer program instructions being configured, together with the processor, to cause the terminal device to perform the method according to any one of claims 1-10. 31. A second network device comprising: processor; and a memory storing computer program instructions, the memory and the computer program instructions being configured to, with the processor, cause the second network device to perform the method of any of claims 11-24 . 32. A first network device, comprising: processor; and a memory storing computer program instructions, the memory and the computer program instructions being configured, with the processor, to cause the first network device to perform the method of any of claims 25-29 . 33. A computer-readable medium storing machine-executable instructions that, when executed by a terminal device, cause the terminal device to perform the method of any of claims 1-10. 34. A computer-readable medium storing machine-executable instructions that, when executed by a network device, cause the network device to perform the method of any of claims 11-24. 35. A computer-readable medium storing machine-executable instructions that, when executed by a network device, cause the network device to perform the method of any of claims 25-29.

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