CN111835389B

CN111835389B - Channel estimation method, related device and system

Info

Publication number: CN111835389B
Application number: CN201910307411.8A
Authority: CN
Inventors: 徐明慧; 陈磊
Original assignee: Chengdu Huawei Technology Co Ltd
Current assignee: Chengdu Huawei Technology Co Ltd
Priority date: 2019-04-16
Filing date: 2019-04-16
Publication date: 2022-04-29
Anticipated expiration: 2039-04-16
Also published as: CN111835389A

Abstract

The embodiment of the invention discloses a channel estimation method, related equipment and a system, which are applied to the technical field of communication, can ensure that the power of a reference signal is not increased, and simultaneously do not influence the channel estimation performance of a receiving node. Wherein, the method comprises the following steps: the method comprises the steps that a first communication device carries out interference pre-elimination and power adjustment on a first reference signal to obtain a sending signal, wherein when the interference power of the first reference signal is larger than or equal to a first preset threshold, the power adjustment mode is modular; and the first communication equipment sends the sending signal to second communication equipment, and the second communication equipment estimates a channel according to the receiving signal of the first reference signal and the effective sending signal of the first reference signal.

Description

Channel estimation method, related device and system

Technical Field

The present application relates to the field of communications technologies, and in particular, to a channel estimation method, a related device, and a system.

Background

In a downlink multi-user-multiple-input-multiple-output (MU-MIMO) communication system, a transmitting node transmits different data to a plurality of receiving nodes on the same time-frequency domain resource through a spatial multiplexing technique. In this case, the transmitting node needs to adopt a correlation technique to separate the channels of the receiving nodes as much as possible, and eliminate mutual interference between the receiving nodes, thereby maximizing the total throughput of the system. At present, a plurality of MU-MIMO technical schemes exist theoretically, and the methods can be generally divided into two types of nonlinear precoding and linear precoding.

In order to solve the power increase caused by the interference pre-cancellation, there are two power adjustment modes in the prior art, namely, a mode calculation mode and a power backoff mode. The two modes can solve the problem of power rise caused by interference pre-elimination, and when the reference signal is pre-coded, in order to accurately estimate the equivalent channel experienced by the data and ensure the correct demodulation of the receiving node, the power adjustment is performed by adopting a power backspace mode instead of a modulo operation. However, when the interference power is too large, the power backoff adjustment mode is ineffective, that is, the power of the signal after interference pre-cancellation cannot be reduced, so that how to design a channel estimation scheme under this condition can ensure that the power of the reference signal is not raised, and at the same time, the channel estimation performance of the receiving node is not affected, which is a technical problem to be solved at present.

Disclosure of Invention

Embodiments of the present invention provide a channel estimation method, a related device, and a system, which can ensure that the power of a reference signal is not increased, and at the same time, the channel estimation performance of a receiving node is not affected.

In a first aspect, an embodiment of the present invention provides a channel estimation method, which is applied to a first communication device side. The method comprises the following steps: the method comprises the steps that interference pre-elimination and power adjustment are carried out on a first reference signal by first communication equipment to obtain a sending signal, wherein when the interference power of the first reference signal is larger than or equal to a first preset threshold, the power adjustment mode is modular. And the first communication equipment sends the sending signal to second communication equipment. By implementing the embodiment of the invention, when the interference power exceeds the threshold value, the sending end adopts a mode of solving the modulus to adjust the power of the reference signal instead of adopting a power back-off mode, so that the power of the reference signal is not increased, and the problem that the method for adjusting the power of the reference signal by using the power back-off mode in the prior art is invalid when the interference power is more than or equal to 1 is avoided.

In one possible design, when the interference power of the first reference signal is smaller than the first preset threshold, the power adjustment manner is power backoff. By implementing the embodiment of the invention, the power adjustment mode can be flexibly changed according to the relation between the interference power value of the first reference signal and the preset threshold value.

Or, when the interference power of the first reference signal is greater than the first preset threshold, the power adjustment mode is modulo. When the interference power of the first reference signal is less than or equal to the first preset threshold, the power adjustment mode is power backoff.

Or, when the interference power of the first reference signal is greater than or equal to the first preset threshold, the power adjustment mode is modulo. When the interference power of the first reference signal is greater than or equal to a second preset threshold and less than the first preset threshold, the power adjustment mode is to reduce the power of other reference signals interfering with the first reference signal. And when the interference power of the first reference signal is smaller than a second preset threshold, the power adjustment mode is power backoff.

Or, when the interference power of the first reference signal is greater than the first preset threshold, the power adjustment mode is modulo. When the interference power of the first reference signal is greater than a second preset threshold and less than or equal to the first preset threshold, the power adjustment mode is to reduce the power of other reference signals interfering with the first reference signal. And when the interference power of the first reference signal is less than or equal to a second preset threshold, the power adjustment mode is power backoff.

Compared with the prior art that the power backoff mode is adopted to reduce the power rise of the non-linear precoding DMRS caused by pre-interference reduction, the embodiment of the invention selects different DMRS power adjustment modes under different interference powers, on the premise that the power of the DMRS signal does not exceed a specified value, a power backspacing mode can be selected for power adjustment to ensure the channel estimation accuracy, when the interference power is larger than or equal to a specified value, the power of the DMRS signal after the interference is subtracted is ensured not to be increased by a mode of modulus calculation, meanwhile, in order to enable a receiving end to estimate a channel according to the modulated DMRS signal, a power adjustment mode selection threshold value and interference information and/or DMRS sequence information are notified to the receiving end, and a terminal or the receiving end determines an effective DMRS transmission signal according to different DMRS power adjustment modes for channel estimation.

In one possible design, the method further includes:

the first communication device sends the interference information of the first reference signal to the second communication device, wherein the interference information of the first reference signal is used for the second communication device to determine an effective sending signal of the first reference signal, and the effective sending signal is used for the second communication device to estimate a channel.

In one possible design, the method further includes:

the first communication device transmits a sequence of second reference signals to the second communication device, where the sequence of second reference signals is used by the second communication device to determine the valid transmission signal.

In a possible design, if the power adjustment mode is modulo, the interference information includes an interference factor corresponding to the first reference signal; if the power adjustment mode is power backoff, the interference information includes a power backoff factor of the first reference signal.

In one possible design, the method further includes:

the first communication device sends the first preset threshold to the second communication device, and the first preset threshold is used for the second communication device to determine the power adjustment mode;

or, the first communication device sends a power adjustment mode identifier to the second communication device, where the power adjustment mode identifier is used to indicate the power adjustment mode.

Alternatively, the method further comprises:

the first communication device sends the first preset threshold and the second preset threshold to the second communication device, and the first preset threshold and the second preset threshold are used for the second communication device to determine the power adjustment mode;

In a second aspect, an embodiment of the present invention provides a channel estimation method, which is applied to a second communication device side. The method comprises the following steps: the method comprises the steps that a second communication device receives a sending signal sent by a first communication device, wherein the sending signal is obtained after the first communication device carries out interference pre-elimination and power adjustment on a first reference signal, and when the interference power of the first reference signal is larger than or equal to a first preset threshold, the power adjustment mode is modular calculation; the second communication device estimates a channel from the received signal of the first reference signal and the valid transmitted signal of the first reference signal. By implementing the embodiment of the invention, when the interference power exceeds the threshold value, the sending end adopts a mode of solving the modulus to adjust the power of the reference signal instead of adopting a power back-off mode, so that the power of the reference signal is not increased, and the problem that the method for adjusting the power of the reference signal by using the power back-off mode in the prior art is invalid when the interference power is more than or equal to 1 is avoided.

In one possible design, before estimating a channel according to the received signal of the first reference signal and the transmitted signal, the second communication device further includes:

the second communication equipment receives interference information of the first reference signal sent by the first communication equipment;

and the second communication equipment determines the effective sending signal according to the interference information.

the second communication equipment receives a sequence of second reference signals sent by the first communication equipment;

the second communication device determining the effective transmission signal according to the interference information, including:

and the second communication equipment determines the effective sending signal according to the interference information and the sequence of the second reference signal.

In one possible design, the method further includes:

the second communication device receives the first preset threshold sent by the first communication device, wherein the first preset threshold is used for the second communication device to determine the power adjustment mode;

or, the second communication device receives a power adjustment mode identifier sent by the first communication device, where the power adjustment mode identifier is used to indicate the power adjustment mode.

Alternatively, the method further comprises:

the second communication device receives the first preset threshold and the second preset threshold sent by the first communication device, and the first preset threshold and the second preset threshold are used for the second communication device to determine the power adjustment mode;

In a third aspect, an embodiment of the present invention provides a channel estimation method, which is applied to a first communication device side. The method comprises the following steps: the first communication equipment performs interference pre-elimination and modulus calculation on the first reference signal to obtain a sending signal; and the first communication equipment sends the sending signal to second communication equipment. By implementing the embodiment of the invention, the sending end adopts the mode of solving the modulus to adjust the power of the reference signal instead of adopting the power back-off mode, so that the power of the reference signal is not increased, and the problem that the method for adjusting the power of the reference signal by using the power back-off in the prior art is invalid when the interference power is more than or equal to 1 is avoided.

In one possible design, further comprising:

In one possible design, the interference information includes an interference factor corresponding to the first reference signal.

In a fourth aspect, an embodiment of the present invention provides a channel estimation method, which is applied to a second communication device side. The method comprises the following steps: the method comprises the steps that a second communication device receives a sending signal sent by a first communication device, wherein the sending signal is obtained by the first communication device after interference pre-elimination and modulus calculation are carried out on a reference signal; the second communication device estimates a channel from the received signal of the first reference signal and the valid transmitted signal of the first reference signal. By implementing the embodiment of the invention, the sending end adopts the mode of solving the modulus to adjust the power of the reference signal instead of adopting the power back-off mode, so that the power of the reference signal is not increased, and the problem that the method for adjusting the power of the reference signal by using the power back-off in the prior art is invalid when the interference power is more than or equal to 1 is avoided.

the second communication device determining the transmission signal according to the interference information, including:

In a fifth aspect, an embodiment of the present invention provides a communication device, which is a first communication device, where the first communication device may include a plurality of functional modules or units, and is configured to correspondingly perform the channel estimation method provided in the first aspect, or the channel estimation method provided in any one of possible implementations of the first aspect.

For example, the first communication device includes: a processing unit and a transmitting unit.

The processing unit is configured to perform interference pre-cancellation and power adjustment on a first reference signal to obtain a transmission signal, where when an interference power of the first reference signal is greater than or equal to a first preset threshold, the power adjustment mode is modulo;

and the sending unit is used for sending the sending signal to the second communication equipment.

In a sixth aspect, an embodiment of the present invention provides a communication device, which is a second communication device, where the second communication device may include a plurality of functional modules or units, and is configured to correspondingly execute the channel estimation method provided in the second aspect, or the channel estimation method provided in any one of possible implementations of the second aspect.

For example, the second communication device includes: a receiving unit and a processing unit.

The receiving unit is configured to receive a transmission signal sent by a first communication device, where the transmission signal is obtained by performing interference pre-cancellation and power adjustment on a first reference signal by the first communication device, and when an interference power of the first reference signal is greater than or equal to a first preset threshold, the power adjustment mode is modulo;

and the processing unit is used for estimating a channel according to the received signal of the first reference signal and the effective transmitted signal of the first reference signal.

In a seventh aspect, an embodiment of the present invention provides a communication device, where the communication device is a first communication device, and the first communication device may include a plurality of functional modules or units, which are configured to correspondingly perform the channel estimation method provided in the third aspect, or the channel estimation method provided in any one of possible implementation manners of the third aspect.

The processing unit is used for carrying out interference pre-elimination and modulus calculation on the first reference signal to obtain a sending signal;

In an eighth aspect, an embodiment of the present invention provides a communication device, which is a second communication device, where the second communication device may include a plurality of functional modules or units, and is configured to correspondingly execute the channel estimation method provided in the fourth aspect, or the channel estimation method provided in any one of the possible implementation manners of the fourth aspect.

The receiving unit is configured to receive a transmission signal sent by a first communication device, where the transmission signal is obtained by the first communication device by performing interference pre-cancellation and modulo calculation on the reference signal;

In a ninth aspect, an embodiment of the present invention provides a communication device, configured to perform the channel estimation method described in the first aspect. The communication device is a first communication device, and the first communication device may include: a memory, and a processor, transmitter, receiver coupled with the memory. Wherein the transmitter is configured to support the first communication device to perform the step of sending information by the first communication device in the channel estimation method provided in the first aspect. The receiver is configured to support the first communication device to perform the step of receiving information by the first communication device in the channel estimation method provided by the first aspect. Wherein the transmitter and the receiver may be integrated into a transceiver. The processor is configured to support the first communication device to perform other processing steps of the channel estimation method provided in the first aspect, except that the first communication device sends and receives information. It should be noted that the transmitter and the receiver in the embodiment of the present invention may be integrated together, or may be coupled through a coupler. The memory is configured to store implementation code of the channel estimation method described in the first aspect, and the processor is configured to execute the program code stored in the memory, that is, to execute the channel estimation method provided in the first aspect, or the channel estimation method provided in any of the possible implementations of the first aspect.

In a tenth aspect, an embodiment of the present invention provides another communication device, configured to perform the channel estimation method described in the second aspect. The communication device is a second communication device, and the second communication device may include: a memory, and a processor, transmitter, receiver coupled with the memory. Wherein the transmitter is configured to support the second communication device to perform the step of sending information by the second communication device in the channel estimation method provided by the second aspect. The receiver is configured to support the second communication device to perform the step of receiving information by the second communication device in the channel estimation method provided by the second aspect. Wherein the transmitter and the receiver may be integrated into a transceiver. The processor is configured to support the second communication device to perform other processing steps of the channel estimation method provided by the second aspect, except that the second communication device sends and receives information. It should be noted that the transmitter and the receiver in the embodiment of the present invention may be integrated together, or may be coupled through a coupler. The memory is configured to store implementation code of the channel estimation method described in the second aspect, and the processor is configured to execute the program code stored in the memory, that is, to execute the channel estimation method provided in the second aspect, or the channel estimation method provided in any of the possible implementations of the second aspect. The memory and the processor may be integrated together or may be coupled by a coupler.

In an eleventh aspect, an embodiment of the present invention provides another communication device, configured to perform the channel estimation method described in the third aspect. The communication device is a first communication device, and the first communication device may include: a memory, and a processor, transmitter, receiver coupled with the memory. Wherein the transmitter is configured to support the first communication device to perform the step of the first communication device transmitting information in the channel estimation method provided in the third aspect. The receiver is configured to support the first communication device to perform the step of receiving information by the first communication device in the channel estimation method provided by the third aspect. Wherein the transmitter and the receiver may be integrated into a transceiver. The processor is configured to support the first communication device to perform other processing steps than transmitting information and receiving information by the first communication device in the channel estimation method provided by the third aspect. It should be noted that the transmitter and the receiver in the embodiment of the present invention may be integrated together, or may be coupled through a coupler. The memory is configured to store implementation code for the channel estimation method described in the third aspect, and the processor is configured to execute the program code stored in the memory, that is, to execute the channel estimation method provided by the third aspect, or the channel estimation method provided by any of the possible implementations of the third aspect. The memory and the processor may be integrated together or may be coupled by a coupler.

In a twelfth aspect, an embodiment of the present invention provides a communication device, configured to perform the channel estimation method described in the fourth aspect. The communication device is a second communication device, and the second communication device may include: a memory, and a processor, transmitter, receiver coupled with the memory. Wherein the transmitter is configured to support the second communication device to perform the step of sending information by the second communication device in the channel estimation method provided in the fourth aspect. The receiver is configured to support the second communication device to perform the step of receiving information by the second communication device in the channel estimation method provided by the fourth aspect. Wherein the transmitter and the receiver may be integrated into a transceiver. The processor is configured to support the second communication device to perform other processing steps of the channel estimation method provided in the fourth aspect, except that the second communication device sends and receives information. It should be noted that the transmitter and the receiver in the embodiment of the present invention may be integrated together, or may be coupled through a coupler. The memory is configured to store implementation code of the channel estimation method described in the fourth aspect, and the processor is configured to execute the program code stored in the memory, that is, to execute the channel estimation method provided in the fourth aspect, or the channel estimation method provided in any of the possible implementations of the fourth aspect.

In a thirteenth aspect, an embodiment of the present invention provides a communication system, including a first communication device and a second communication device. Wherein the first communication device may be the first communication device as described in the aforementioned fifth aspect or ninth aspect, and the second communication device may be the second communication device as described in the aforementioned sixth aspect or tenth aspect.

In a fourteenth aspect, an embodiment of the present invention provides a communication system, which includes a first communication device and a second communication device. Wherein the first communication device may be the first communication device as described in the aforementioned seventh aspect or eleventh aspect, and the second communication device may be the second communication device as described in the aforementioned eighth aspect or twelfth aspect.

In a fifteenth aspect, an embodiment of the present invention provides a computer-readable storage medium, which stores instructions that, when executed on a computer, cause the computer to perform the channel estimation method described in any one of the above aspects.

In a sixteenth aspect, an embodiment of the present invention provides a computer program product containing instructions which, when run on a computer, cause the computer to perform the channel assessment method described in any of the above aspects.

In a seventeenth aspect, an embodiment of the present invention provides a communication chip, where the communication chip may include: a processor, and one or more interfaces coupled to the processor. The processor may be configured to call an implementation program of the channel estimation method provided in any one of the foregoing aspects from the memory, and execute instructions included in the program. The interface may be used to output a processing result of the processor.

Drawings

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

Fig. 1 is a schematic diagram of a wireless communication system according to an embodiment of the present invention;

fig. 2 is a schematic diagram of a hardware structure of a terminal according to an embodiment of the present invention;

fig. 3 is a schematic hardware structure diagram of a network device according to an embodiment of the present invention;

FIG. 4 is a functional block diagram of a communication transport flow involved in the practice of the present invention;

FIG. 5 is a schematic diagram of two power adjustment approaches according to an embodiment of the present invention;

fig. 6 is a flowchart illustrating a channel estimation method according to an embodiment of the present invention;

fig. 7 is a flowchart illustrating another channel estimation method according to an embodiment of the present invention;

fig. 8 is a schematic diagram of a DMRS pilot pattern on a single OFDM symbol provided by an embodiment of the present invention;

fig. 9 is a flowchart illustrating another channel estimation method according to an embodiment of the present invention;

fig. 10 is a flowchart illustrating another channel estimation method according to an embodiment of the present invention;

fig. 11 is a schematic logical structure diagram of a wireless communication system, a first communication device, and a second communication device according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of a communication chip according to an embodiment of the present invention.

Detailed Description

The terminology used in the description of the embodiments section of the present application is for the purpose of describing particular embodiments of the present application only and is not intended to be limiting of the present application.

Fig. 1 shows a wireless communication system to which the present application relates. The wireless communication system includes, but is not limited to, a Long Term Evolution (LTE) system, a future evolution fifth Generation mobile communication (5G) system, a New Radio (NR) system, and the like. As shown in fig. 1, the wireless communication system 100 may include: one or more network devices 101 (fig. 1 takes 1 network device as an example), one or more terminals 103, and a core network (not shown). Wherein:

the network device 101 may be a base station, and the base station may be configured to communicate with one or more terminals, and may also be configured to communicate with one or more base stations having partial terminal functions (e.g., communication between a macro base station and a micro base station, such as an access point). The base station may be an evolved Node B (eNB or eNodeB) in an LTE system, and a next-generation Node B (gNB) in a 5G system, a new-air-interface (NR) system, and so on. A base station may also be an Access Point (AP), a transmission point (TRP), a Central Unit (CU), or other network entity, and may include some or all of the functionality of the above network entities. The wireless communication system 100 may include several different types of network devices 101, such as macro base stations (macro base stations), micro base stations (micro base stations), and so on. Network device 101 may apply different radio technologies, such as a cell radio access technology, or a WLAN radio access technology.

The terminals 103 may be distributed throughout the wireless communication system 100 and may be stationary or mobile. In some embodiments of the present application, the terminal 103 may be a mobile device (including but not limited to a cell phone), a wearable device (including but not limited to a bracelet), a home appliance, a car mounted device, a mobile station (mobile station), a mobile unit (mobile unit), a machine-to-machine (M2M) terminal, a wireless unit, a remote unit, a terminal agent, a mobile client, and so forth. The terminal 103 may also be a User Equipment (UE), a user terminal, or the like.

In the present application, the wireless communication system 100 may be a Multiple Input Multiple Output (MIMO) communication system. Wherein: the network device 101 may be configured with a large-scale antenna array and utilize beamforming techniques to steer the antenna array to form beams of different orientations. In order to cover the entire cell 107, the network device 101 needs to use a plurality of differently directed beams. For example, in the downlink process, the network device 101 may transmit a wireless signal (such as a downlink Reference Signal (RS)) using beams of different orientations in sequence. Meanwhile, the terminal 103 measures the transmission beam and determines the signal quality of the transmission beam that can be received by the terminal 103. Wherein RS may include, but is not limited to: a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), or a demodulation reference signal (de-modulation reference signal (DMRS).

In future communication systems, the terminal 103 may be configured with an antenna array, or may convert different beams to transmit and receive signals. That is, in the wireless communication system 100, both the network device 101 and the terminal 103 may communicate using multiple beams.

The first communication device mentioned in the following embodiments may be the network device 101 in the embodiment shown in fig. 1, and the second communication device may be the terminal 103 in the embodiment shown in fig. 1.

It should be noted that the terms "system" and "network" in the embodiments of the present application may be used interchangeably. The "plurality" means two or more, and in view of this, the "plurality" may also be understood as "at least two" in the embodiments of the present application. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" generally indicates that the preceding and following related objects are in an "or" relationship, unless otherwise specified.

Referring to fig. 2, fig. 2 illustrates a terminal 200 provided by some embodiments of the present application. As shown in fig. 2, the terminal 200 may include: one or more terminal processors 201, memory 202, receiver 205, transmitter 206, coupler 207, antenna 208, terminal interface 202, and input-output modules (including audio input-output module 210, key input module 211, and display 212, etc.). These components may be connected by a bus 204 or otherwise, as illustrated in FIG. 2 by a bus connection. Wherein:

transmitter 206 may be configured to perform transmit processing on signals output by terminal processor 201, such as directional transmission via beamforming. Receiver 205 may be configured to perform receive processing, e.g., directional reception via beamforming, on mobile communication signals received by antenna 208. In some embodiments of the present application, the transmitter 305/receiver 306 may include a beamforming controller for multiplying the transmit/receive signals by the weight vectors W1, … …, Wm to control the directional transmission/reception of the signals.

In some embodiments of the present application, the transmitter 206 and the receiver 205 may be considered as one wireless modem. In the terminal 200, the number of the transmitters 206 and the receivers 205 may be one or more. The antenna 208 may be used to convert electromagnetic energy in the transmission line to electromagnetic energy in free space, or vice versa. The coupler 207 is used to divide the mobile communication signal received by the antenna 208 into a plurality of paths and distribute the plurality of paths to the plurality of receivers 205.

In addition to the transmitter 206 and receiver 205 shown in fig. 2, the terminal 200 may also include other communication components, such as a GPS module, a Bluetooth (Bluetooth) module, a wireless fidelity (Wi-Fi) module, and so forth. Not limited to the above-expressed wireless communication signals, the terminal 200 may also support other wireless communication signals, such as satellite signals, short-wave signals, and so forth.

The input and output module may be used to realize interaction between the terminal 200 and the terminal/external environment, and may mainly include an audio input and output module 210, a key input module 211, a display 212, and the like. Specifically, the input/output module may further include: cameras, touch screens, sensors, and the like. The input and output modules communicate with the terminal processor 201 through the terminal interface 209.

Memory 202 is coupled to terminal processor 201 for storing various software programs and/or sets of instructions. In particular, the memory 202 may include high speed random access memory, and may also include non-volatile memory, such as one or more magnetic disk storage devices, flash memory devices, or other non-volatile solid state storage devices. The memory 202 may store an operating system (hereinafter referred to simply as a system), such as an embedded operating system like ANDROID, IOS, WINDOWS, or LINUX. The memory 202 may also store a network communication program that may be used to communicate with one or more additional devices, one or more terminal devices, one or more network devices. The memory 202 may further store a terminal interface program, which may vividly display the content of the application program through a graphical operation interface, and receive a control operation of the terminal on the application program through input controls such as menus, dialog boxes, and buttons.

In some embodiments of the present application, the memory 202 may be used to store an implementation program of the channel estimation method provided in one or more embodiments of the present application on the terminal 200 side. For the implementation of the channel estimation method provided in one or more embodiments of the present application, please refer to the following embodiments.

The terminal processor 201 is operable to read and execute computer readable instructions. Specifically, the terminal processor 201 may be configured to invoke a program stored in the memory 212, for example, a program implemented on the terminal 200 side by the channel estimation method provided in one or more embodiments of the present application, and execute instructions contained in the program.

It is to be appreciated that the terminal 200 can be the terminal 103 in the wireless communication system 100 shown in fig. 1 and can be implemented as a mobile device, a mobile station (mobile station), a mobile unit (mobile unit), a wireless unit, a remote unit, a terminal agent, a mobile client, a Customer Premises Equipment (CPE), and so on.

It should be noted that the terminal 200 shown in fig. 2 is only one implementation manner of the embodiment of the present application, and in practical applications, the terminal 200 may further include more or less components, which is not limited herein.

Referring to fig. 3, fig. 3 illustrates a network device 300 provided by some embodiments of the present application. As shown in fig. 3, the network device 300 may include: one or more network device processors 301, memory 302, transmitter 305, receiver 306, coupler 307, and antenna 308. These components may be connected by a bus 304, or otherwise, as illustrated in FIG. 3 by way of example. Wherein:

optionally, the network device 300 may also include a wired interface, which may be used for the network device 300 to communicate with other communication devices, such as other network devices.

The transmitter 305 may be configured to transmit the signal output by the network device processor 301, for example, by beamforming for directional transmission. Receiver 306 may be used for receive processing of mobile communication signals received by antenna 308, e.g., directional reception via beamforming. In some embodiments of the present application, the transmitter 305/receiver 306 may include a beamforming controller for multiplying the transmit/receive signals by the weight vectors W '1, … …, W'm to control the directional transmission/reception of the signals.

In some embodiments of the present application, the transmitter 305 and the receiver 306 may be considered as one wireless modem. In the network device 300, the number of the transmitters 305 and the receivers 306 may be one or more. The antenna 308 may be used to convert electromagnetic energy in the transmission line to electromagnetic energy in free space or vice versa. Coupler 307 may be used to multiplex the mobile communications signal to a plurality of receivers 306.

Memory 302 is coupled to network device processor 301 for storing various software programs and/or sets of instructions. In particular, the memory 302 may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory 302 may store an operating system (hereinafter, referred to as a system), such as an embedded operating system like uCOS, VxWorks, RTLinux, etc. The memory 302 may also store a network communication program that may be used to communicate with one or more additional devices, one or more terminal devices, one or more network devices.

The network device processor 301 may be configured to perform radio channel management, implement call and communication link setup and teardown, provide cell switching control for terminals within the control area, and the like.

In embodiments of the present application, the network device processor 301 may be configured to read and execute computer readable instructions. Specifically, the network device processor 301 may be configured to invoke a program stored in the memory 302, for example, an implementation program of the channel estimation method provided in one or more embodiments of the present application, on the network device 300 side, and execute instructions contained in the program.

It is understood that the network device 300 may be the network device 101 in the wireless communication system 100 shown in fig. 1, and may be implemented as a base transceiver station, a wireless transceiver, a Basic Service Set (BSS), an Extended Service Set (ESS), a NodeB, an eNodeB, an access point or a TRP, etc.

It should be noted that the network device 300 shown in fig. 3 is only one implementation manner of the embodiment of the present application, and in practical applications, the network device 300 may further include more or less components, which is not limited herein.

The method can be applied to but not limited to a MIMO system, wherein a precoding technology is a very important step of MIMO, before precoding, the system firstly maps data information to be sent to different layers through layer mapping so that the data information is distributed to different layers in a certain mode, then maps the data information distributed to the layers to a physical antenna through the precoding technology, and part of necessary signal processing processes which are difficult to implement at a receiving end are transferred to a transmitting end for carrying out, so that the signal performance of a transmission process is ensured. Fig. 4 is a schematic diagram of functional modules of a communication transmission flow according to the present invention. The sending end carries out coding, symbol modulation, mapping and precoding on a data bit stream to be sent aiming at data, carries out mapping and precoding on a DMRS (demodulation reference signal), and combines and sends out a coded data signal and the DMRS through a channel. The receiving end receives signals from a channel, performs signal demapping, separates the received signals into data receiving signals and DMRS receiving signals, performs channel estimation by using the DMRS receiving signals, and performs data equalization and demodulation based on the channel estimation, that is, for the data receiving signals, the receiving end performs equalization, symbol demodulation and decoding, and finally recovers data bit streams.

Since the reference signal and the data may adopt different precoding manners, the functional block flows of the reference signal and the data are separately described in fig. 4 (the solid line represents the functional block and the flow of the data, and the dotted line represents the functional block and the flow of the DMRS), and the use of the same precoding block by the reference signal and the data is not limited. It should be noted that the functional module shown in fig. 4 is only an example, and in practical applications, at least one of the functional modules may further include a digital-to-analog converter (DAC), a Power Amplifier (PA), a Low Noise Amplifier (LNA), an analog-to-digital converter (ADC), and the like.

Typical precoding schemes can be classified into linear precoding and nonlinear precoding, and each precoding scheme has a suitable working scenario. The linear precoding complexity is low, and the method is suitable for scenes with small interference among UE; the nonlinear precoding complexity is high, the influence of interference on performance is reduced by a preprocessing mode at a transmitting end, and the method is suitable for scenes with high interference among UE.

And the flow of the nonlinear precoding introduces an interference elimination matrix or a feedback matrix B to eliminate the interference in advance. The feedback matrix B and the channel matrix H satisfy the following relation:

H^H＝QR＝QL^H

G＝diag(1/r₁₁,1/r₂₂,...,1/r_NN)＝diag(1/l₁₁,1/l₂₂,...,1/l_NN)

B＝GR^H＝GLF＝Q

namely, the nonlinear precoding firstly carries out QR decomposition on a channel matrix H to obtain a Q matrix and a lower triangular matrix L. QR decomposition is a decomposition mode of the matrix, one matrix is decomposed into a product of a semi-orthogonal matrix Q and an upper triangular matrix R, and the upper triangular matrix R is transposed and conjugated to obtain a lower triangular matrix L. The lower triangular matrix L can be represented as:

wherein, the k row and the j column (k is not equal to j) are provided with an element l_kjAnd represents the interference of the j-th layer signal to the k-th layer signal. The interference is caused by the characteristics of the channel, and in the nonlinear precoding, the transmitting end can perform interference cancellation on the signal to be transmitted in advance, namely, the interference is cancelled in advance.

Because the interference is not related to the original signal, the overall power of the signal after the interference is eliminated in advance is increased, and for the problem, there are generally two ways to adjust the power of the signal after the power is increased:

the first method comprises the following steps: module calculation, as shown in (a) of fig. 5, mapping the signal after interference pre-cancellation back to the constellation range to which the original Quadrature Amplitude Modulation (QAM) signal belongs, that is, the middle solid line frame shown in (a) of fig. 5, where, for example, a is the original QAM signal, B is the signal after interference pre-cancellation, C is the signal after module calculation, the solid line frame is the original constellation range, the dashed line frame is the extended constellation, and the relative position of B in the extended constellation (the dashed line frame in (a) of fig. 5) is the same as the phase position of C in the original constellation (the middle solid line frame in (a) of fig. 5).

And the second method comprises the following steps: power backoff, as shown in (B) of fig. 5, multiplying the original QAM signal by a certain power backoff factor λ ∈ (0,1), to ensure that the signal power after interference cancellation in advance is 1 (average power of multiple transmitted signals), where a in (B) of fig. 5 is the original QAM signal, B is the signal obtained after interference cancellation in advance of the original signal, first multiplying the original signal by the power backoff factor to obtain λ a, subtracting the interference in advance to obtain a signal C, and the difference between C and λ a is the same as the difference between B and a; the power back-off factor is determined by the interference power, the lower the interference power, the higher the power back-off factor, the higher the interference power, and the lower the power back-off factor, that is, the power back-off factor of the k layer and the interference power on the k layer satisfy the following formula one:

wherein, |_kiL is a pair_kiModulus, l_kiIs a plurality of numbers. Lambda [ alpha ]_kI.e. the power back-off factor of the k-th layer,

i.e. the interference power on the k-th layer.

In summary, assume that the original QAM signal at the k-th layer is d_kThe signal after interference pre-cancellation is

The signal after power adjustment, i.e. the signal before multiplying the pre-coding matrix, is

According to the nonlinear precoding process, the following formula two and formula three are satisfied:

wherein M is_enA modulus flag in the case of non-linear precoding is shown, a 1 indicates the power of the signal adjusted by the modulus method, and a 0 indicates the work of adjusting the signal by the power back-off methodAnd (4) rate. a is the signal increment introduced during the modulus calculation, which is called modulus calculation for short, and the modulus calculation is related to the modulation mode of the original signal.

Because the modulus is related to interference and an original signal at the same time, the modulus is unknown or random, that is, when the data adopts a nonlinear precoding scheme, if the DMRS also uses nonlinear precoding, the DMRS can eliminate interference in advance to increase the signal power, and in order to accurately estimate a channel by using the DMRS, the transmit-receive signal needs to be known.

As can be known from the relational expression between the power backoff factor and the interference (i.e., the first expression), when the interference power is greater than 1, the power backoff method is invalid, that is, the average power of the DMRS on each Resource Element (RE) is greater than 1, and in NR, the DMRS and data are not generally multiplexed on the same Orthogonal Frequency Division Multiplexing (OFDM) symbol, and at this time, the peak-to-average power ratio (PAPR) of the symbol on which the DMRS is mapped is increased, which affects the system performance. When the interference power is equal to 1, the power backoff factor is 0, that is, the effective transmit signal power of the DMRS is 0, and the corresponding received signal is invalid and cannot be used for channel estimation.

Aiming at the scene that both data and DMRS use nonlinear precoding, the channel estimation method is designed, the power of the DMRS can be ensured not to be raised under any condition (any value of interference power), the channel estimation performance is not influenced, and the problem that the method for adjusting the power of the DMRS by using power backoff in the prior art is invalid when the interference power is more than or equal to 1 is solved.

Based on the foregoing embodiments corresponding to the wireless communication system 100, the terminal 200, and the network device 300, respectively, the present embodiment provides a channel estimation method. Referring to fig. 6, a flow chart of a channel estimation method provided in the present application is schematically shown. As shown in fig. 6, the method includes the following steps.

S601: the first communication device performs interference pre-cancellation and power adjustment on the first reference signal to obtain a sending signal, wherein when the interference power of the first reference signal is greater than or equal to a first preset threshold, the power adjustment mode is modulo.

S602: the first communication device transmits the transmission signal to the second communication device, and the second communication device receives the transmission signal transmitted by the first communication device.

S603: the second communication device estimates a channel from the effective transmitted signal and the received signal of the first reference signal.

The reference signal in the embodiment of the present invention includes, but is not limited to, DMRS. The following examples illustrate DMRS. The first preset threshold may be a preset value or equal to 1 (assuming that the average power of the multiple transmitted signals is 1).

Optionally, the first communication device may be a network device (e.g., a base station), and the second communication device may be a terminal, and the following description takes the first communication device as the base station and the second communication device as the terminal as an example.

By implementing the embodiment of the invention, when the interference power exceeds the threshold value, the sending end adopts a mode of solving the modulus to adjust the power of the reference signal instead of adopting a power back-off mode, so that the power of the reference signal is not increased, and the problem that the method for adjusting the power of the reference signal by using the power back-off mode in the prior art is invalid when the interference power is more than or equal to 1 is avoided.

Optionally, in order to enable the receiving end to recover the transmitted signal of the first reference signal and further perform channel estimation by using the transmitted signal and the received signal of the first reference signal, the transmitting end needs to notify the receiving end of the interference information of the first reference signal and the original sequence of the second reference signal, and the receiving end can obtain the effective transmitted signal of the first reference signal according to the interference information of the first reference signal and the original sequence information of the second reference signal, so as to estimate a channel and demodulate data based on the effective transmitted signal. Wherein the second reference signal is a signal interfering with the first reference signal. The process can be specifically referred to the first embodiment shown in fig. 7. Wherein the content of the first and second substances,

s701: the base station sends a first preset threshold to the terminal or the base station and the terminal agree on the first preset threshold in advance.

S702: the base station acquires a channel and acquires interference information of each layer according to the channel.

S703: and the base station confirms the interference information of each layer of DMRS by combining the current DMRS configuration information.

S704: the base station sends the interference information of the DMRS and/or the DMRS sequence information of other layers or other terminals to the terminal, and the terminal receives the interference information of the DMRS sent by the base station and/or the DMRS sequence information of other layers or other terminals.

S705: and the base station performs nonlinear precoding on the data and the DMRS, wherein when the interference power of the DMRS is greater than or equal to a first preset threshold, the base station performs power adjustment on the DMRS in a mode of solving the mode.

S706: and the base station sends the nonlinear precoded data and the DMRS to the terminal, and the terminal receives the nonlinear precoded data and the DMRS sent by the base station.

S707: the terminal determines the power adjustment mode of the DMRS according to the received first preset threshold and the interference information of the DMRS, determines effective sending signals of the DMRS according to the interference information of the DMRS and/or DMRS sequence information of other layers or other terminals, estimates channels by combining the receiving signals of the DMRS, balances data and completes data demodulation.

The base station end or the transmitting end needs to acquire a channel, determines the interference information of the DMRS according to the channel, transmits the interference information and the DMRS sequence information of other layers or other UEs to the terminal or the receiving end, and simultaneously performs nonlinear precoding on data and the DMRS, wherein the power adjustment scheme of the DMRS is determined by the base station or the transmitting end according to the interference power and transmits the data after the nonlinear precoding and the DMRS, and the terminal or the receiving end determines the effective transmission signal of the DMRS according to the received information and completes channel estimation for data equalization and demodulation by combining the receiving signal of the DMRS.

Optionally, if the power adjustment is modulo, the interference information includes an interference factor (or referred to as an interference coefficient) corresponding to the first reference signal. As shown in the above formula, the interference factor may be

The corresponding numerical value may also be one or more

The corresponding numerical value can also be l_kkAnd one or more of_ki(i<k) The respective corresponding numerical values.

Taking 5G NR as an example, considering that when DMRS in 5G NR only occupies one Orthogonal Frequency Division Multiplexing (OFDM) symbol, the number of DMRS ports occupying the same subcarrier (which may interfere with each other) on the symbol is 2, as shown in fig. 8, when DMRS is configured as type 1, port 0/1 occupies the same subcarrier, which is considered as a Code Division Multiplexing (CDM) group, port 2/3 occupies the same subcarrier, which is considered as another CDM group, and CDM is orthogonal to frequency division between groups, where the lower triangular matrix when DMRS is non-linearly precoded can be simplified as follows:

that is, DMRSs between CDM groups do not interfere with each other, and DMRSs on a layer ranked further back in a CDM group are interfered by DMRSs on a layer ranked further front. When there are only two DMRS ports in the CDM group, the DMRS in the first layer in the group has no interference signal, and the DMRS in the second layer in the group is only interfered by the DMRS in the first layer, and as described above, the signals obtained by subtracting the interference from each layer in the CDM group are:

when the number of DMRS ports in a CDM group or the number of DMRS ports occupying the same subcarrier is 4, similar to the above case, the signals obtained by subtracting interference from each layer in the CDM group are:

wherein

And

are respectively as

And

and (4) carrying out power adjustment to obtain a signal.

As described above, when the number of DMRS ports within a CDM group is 2 or 4, interference factors determined by channels are respectively 2 or 4

Or

Corresponding interference power is respectively

Or

The channel estimation procedure of the second communication device is described by taking the number of DMRS within the CDM group as 2 as an example as follows:

assume that the DMRS original sequence or original QAM signal within a CDM group is d₁And d₂The DMRS of the first layer is not affected by any interference and does not need to be subjected to power adjustment, namely the DMRS of the first layer transmits a signal d₁The receiving end does not need to perform additional processing, and does not need to describe in detail, and the interference factor or interference coefficient received by the DMRS of the second layer is l₂₁/l₂₂Then the interference is subtracted and the modulo signal is:

wherein a is modulus, and when the modulation mode of the DMRS is QPSK (quadrature phase shift keying), a needs to satisfy:

wherein real () and imag () denote real and imaginary parts of ". cndot.", respectively, m and n are integers, and m and n are unique.

After passing through the channel, the superimposed interference and the interference term subtracted in advance cancel each other out, that is, the DMRS received signal of the second layer is:

r₂＝l₂₂(d₂+a)+n₂

wherein n is₂Representing noise on the second layer DMRS.

As can be seen from the above equation, the effective transmission signal of the DMRS in the second layer in the CDM group is d₂+ a. When the interference factor and the DMRS sequence of the first layer are notified to the receiving end, the receiving end can determine the only modulus a according to the information, and further determine the effective sending signald₂+ a, combined with the received signal of DMRS, the effective channel l experienced by the data can be estimated₂₂The method is used for data equalization demodulation.

In the above example, the base station transmits the interference factor l suffered by the DMRS of the second layer to the receiving terminal corresponding to the second layer in the CDM group₂₁/l₂₂And original sequence d of DMRS of the first layer₁And the receiving terminal corresponding to the second layer can obtain the signal with the second layer DMRS power adjusted according to the fourth calculation formula

Due to the fact that

d₁、d₂If the unique solution of a can be obtained according to the formula four after the known, then the effective transmission signal d of the second layer DMRS can be further obtained₂+a。

Optionally, if a base station schedules DMRS ports of one CDM group to the same terminal, and since a DMRS sequence is generally scrambled by DL-DMRS-Scrambling-ID, when DL-DMRS-Scrambling-ID is configured as UE-ID (including but not limited to cell-radio network temporary identifier (C-RNTI), random access radio network response temporary identifier (RA-RNTI), temporary C-RNTI, and transmission power control radio network temporary identifier (transmit power control radio network temporary identifier, TPC-RNTI)), no additional signaling is needed to notify the DMRS original sequence. Similarly, if DMRS sequences in the same CDM group are assigned with the same scrambling value and the DMRS sequences in the CDM group are informed of the same scrambling value by pre-agreement or higher layer signaling (e.g., RRC, MAC-CE), no additional signaling is required to inform the DMRS original sequences. At this time, only the interference factor may be notified to the terminal.

Optionally, if the first preset threshold is defined by a protocol, no additional signaling is needed to notify the first preset threshold. At this time, only the interference factor may be notified to the terminal.

Optionally, interference when the first reference signal is interferedAnd when the power is smaller than a first preset threshold, the power adjustment mode of the DMRS is power backoff. Or when the interference power of the DMRS is greater than a first preset threshold, the power adjustment mode of the DMRS is modular, and when the interference power of the DMRS is less than or equal to the first preset threshold, the power adjustment mode of the DMRS is power backoff. See table 1 below for details. When the power adjustment mode is power backoff, the effective transmission signal of the DMRS is lambda_kd_k。

TABLE 1 interference power and DMRS power adjustment mode relationship schematic

The influence of a power adjustment factor introduced by adjusting the power on the original QAM signal is small, and the power of the DMRS useful signal used for estimating the channel is lambda_k ²The reduction is limited, the influence on the channel estimation performance is small, therefore, the power of the DMRS can be adjusted by a power backoff mode at the moment, compared with the mode calculation, the channel estimation accuracy is sacrificed a little, but the cost for informing interference information (the interference factors) and/or DMRS sequences of each layer in a CDM group is saved, especially when 4 DMRS ports are in the CDM group, or the channel change speed is fast, or the change on the channel frequency domain is large

Fast with frequency point change), the gain resulting from saving this signaling overhead will be higher than the performance degradation due to reduced channel estimation accuracy.

Due to power backoff, the effective transmission signal of the second layer DMRS in CDM group is lambda₂d₂Therefore, the receiving end only needs to know λ₂That is, the transmitting end may inform only the interference power λ at this time₂ ²Or directly informs of the power back-off factor lambda₂Instead of the interference factor notified in the modulo state and/or the DMRS sequence within the CDM group, the signaling overhead may be further reduced.

For the first layer DMRS within CDM group, it is transmitted since it is not affected by any interferenceThe signal and the effective transmission signal are both d₁。

By implementing the embodiment of the invention, the power adjustment mode can be flexibly changed according to the relation between the interference power value of the first reference signal and the preset threshold value.

It should be noted that in the embodiment shown in fig. 7, both the transmitting end and the receiving end need to compare the interference power with a preset threshold to determine the current power adjustment mode. Therefore, the threshold value needs to be notified to the terminal by the base station or the threshold value is predetermined, the threshold value can be obtained by simulation or theoretical analysis (for example, the signal-to-noise ratio of the effective transmission signal in the two modes of comparing the mode and the power backoff, the threshold is the interference power with the same signal-to-noise ratio in the two modes), and if the threshold value needs to be notified, the signaling is not limited and can be Radio Resource Control (RRC) signaling, media access control-control element (MAC-CE) signaling or Downlink Control Information (DCI) signaling.

The notification of the interference information (interference factor or interference coefficient or interference power or power backoff factor) and/or the DMRS sequence and the non-linear precoding, and the transmission of the data and the DMRS are only exemplary, and the present invention is not limited thereto, for example, the data and the DMRS may be subjected to non-linear precoding first, and then the interference information (interference factor or interference coefficient or interference power or power backoff factor), the DMRS sequence, and the precoded data and the DMRS may be transmitted to the terminal at the same time. Like the notification threshold, the notification signaling of the sequence of the interference information (interference factor or interference coefficient or interference power or power backoff factor) and/or the DMRS may be at least one of RRC, MAC-CE, DCI.

Optionally, in addition to the foregoing two power adjustment manners of modulo and power backoff, other manners of adjusting power may be introduced during non-linear precoding, such as reducing DMRS power of a first k-1 layer in a CDM group to reduce interference of the first k-1 layer on a kth layer, thereby increasing a signal power backoff factor of the kth layer, improving DMRS effective signal power of the kth layer, and improving channel estimation performance. In this case, at least two thresholds may be defined, and if the interference powers are in different intervals, different power adjustment manners are selected, for example, when the interference power of the DMRS is greater than or equal to a first preset threshold, the power adjustment manner of the DMRS is modulo, when the interference power of the DMRS is greater than or equal to a second preset threshold and less than the first preset threshold, the power adjustment manner of the DMRS on the kth layer is to reduce the power of the DMRS on the first k-1 layer, and when the interference power of the DMRS is less than the second preset threshold, the power adjustment manner of the DMRS is power backoff. Or when the interference power of the DMRS is greater than a first preset threshold, the power adjustment mode of the DMRS is modular, when the interference power of the DMRS is greater than a second preset threshold and is less than or equal to the first preset threshold, the power adjustment mode of the DMRS at the k-th layer is to reduce the power of the DMRS at the front k-1 layer, and when the interference power of the DMRS is less than or equal to the second preset threshold, the power adjustment mode of the DMRS is power backoff. See table 2 below for details:

table 2 interference power and DMRS power adjustment mode relation schematic

The purpose of selecting in the partial power adjustment mode can be realized by configuring or appointing that the threshold value on the left side of the equation is larger than or equal to the threshold value on the right side of the equation, or configuring the threshold value 1<0, or configuring the threshold value 2 as positive infinity to invalidate the corresponding row in the table. Table 2 is merely an example, in an actual application, the threshold may be more (the number of rows may be more), and the corresponding relationship between the adjustment manner and the threshold may also be interchanged.

Aiming at the power adjustment mode of reducing the DMRS power of the front k-1 layer, because the DMRS transmitting signal power of the front k-1 layer is reduced, the interference power of the signal of the k-th layer DMRS is reduced, and in order to ensure that the power of the k-th layer transmitting signal is not more than 1, a power back-off factor lambda can be introduced_kAnd satisfies the following formula:

where ρ is_iWork of DMRS for first k-1A rate back-off factor. Therefore, for a terminal or a receiving end corresponding to the kth layer DMRS, threshold information (or a power adjustment mode identifier) and a power backoff factor λ need to be notified_k. And respectively informing the power back-off factors of each layer to the terminal or the receiving end corresponding to the front k-1 layer DMRS so that the terminal corresponding to the front k-1 layer DMRS can recover the effective transmission signal of the DMRS, and carrying out channel estimation based on the effective transmission signal. It should be noted that the power back-off factor of k-1 is different from the power back-off factor of formula three or the power back-off factor mentioned above, such as ρ in formula five_iShown (wherein M is_enWhere 0 denotes power backoff adjustment of DMRS transmission signal power of k-th layer, M_enWhere 1 denotes adjusting DMRS transmission signal power of the k-th layer before adjusting DMRS transmission signal power of the k-1 layer, M _en2 denotes modulo adjustment of DMRS transmission signal power of the k-th layer), is performed on

Signal ensemble multiplied by power back-off factor ρ_iAnd acquire

The way of adjusting the power before the signal is irrelevant, i.e. to

Multiplication by a power back-off factor p_iPreviously, can be passed through the pair d_iPerform power back-off or pair

Obtaining by modulo

In the embodiment shown in fig. 7, compared with the prior art that the power backoff method is used to reduce the power increase introduced by the non-linear precoding DMRS due to pre-interference reduction, in the embodiment of the present invention, different DMRS power adjustment methods are selected under different interference powers, on the premise that the power of the DMRS signal does not exceed a specified value, a power backspacing mode can be selected for power adjustment to ensure the channel estimation accuracy, when the interference power is larger than or equal to a specified value, the power of the DMRS signal after the interference is subtracted is ensured not to be increased by a mode of modulus calculation, meanwhile, in order to enable a receiving end to estimate a channel according to the modulated DMRS signal, a power adjustment mode selection threshold value and interference information and/or DMRS sequence information are notified to the receiving end, and a terminal or the receiving end determines an effective DMRS transmission signal according to different DMRS power adjustment modes for channel estimation.

Fig. 9 is a schematic flow chart of a channel estimation method according to a second embodiment of the present invention. Wherein the content of the first and second substances,

s901: the base station acquires a channel and acquires interference information of each layer according to the channel.

S902: and the base station confirms the interference information of each layer of DMRS by combining the current DMRS configuration information.

S903: the base station sends the power adjustment identification of the DMRS and the interference information of the DMRS and/or the DMRS sequence information of other layers or other terminals to the terminal, and the terminal receives the interference information of the DMRS and/or the DMRS sequence information of other layers or other terminals sent by the base station.

S904: and the base station performs nonlinear precoding on the data and the DMRS, wherein when the interference power of the DMRS is greater than or equal to a first preset threshold, the base station performs power adjustment on the DMRS in a mode of solving the mode.

S905: and the base station sends the nonlinear precoded data and the DMRS to the terminal, and the terminal receives the nonlinear precoded data and the DMRS sent by the base station.

S906: the terminal determines the power adjustment mode of the DMRS according to the received power adjustment identifier, determines an effective sending signal of the DMRS according to the interference information of the DMRS and/or DMRS sequence information of other layers or other terminals, estimates a channel by combining the receiving signal of the DMRS, balances data and completes data demodulation.

The difference between the second embodiment shown in fig. 9 and the first embodiment shown in fig. 7 is that the DMRS power adjustment threshold is not notified or agreed. And selecting a DMRS power adjustment mode according to the interference power, executing the DMRS power adjustment mode only at a base station end or a transmitting end, directly informing and transmitting the DMRS power adjustment mode to a terminal or a receiving end, determining the currently used power adjustment mode by the receiving end according to the received information, and carrying out corresponding processing on the DMRS so as to correctly estimate a channel.

If DMRS modulo identity is defined, when the receiving end determines that the current precoding is non-linear precoding, the modulo identity may be defined as follows:

and the modulus identifier is 0: and adjusting the power of the DMRS in a power backoff mode.

And (3) the modulus identifier is 1: and adjusting the power of the DMRS in a mode of solving the mode.

Or other manners of adjusting the DMRS power may also be introduced, such as reducing the DMRS power of the first k-1 layer in the CDM group to reduce the interference of the first k-1 layer to the kth layer, where the modulo identity may be defined as:

And (3) the modulus identifier is 1: and adjusting the power of the DMRS in a mode of reducing the power of the front k-1 layer DMRS.

And the modulus identifier is 2: and adjusting the power of the DMRS in a mode of solving the mode.

In addition, the joint indication can be performed in combination with the current precoding mode:

and the modulus identifier is 0: and linear precoding.

And (3) the modulus identifier is 1: and carrying out nonlinear precoding and adjusting the power of the DMRS in a power backoff mode.

And the modulus identifier is 2: and nonlinear precoding and adjusting the power of the DMRS in a mode of modulus calculation.

And (3) the modulus identifier: and adjusting the power of the DMRS in a mode of nonlinear precoding and reducing the power of the front k-1 layer DMRS.

In addition, because different power adjustment modes need to notify different interference information, such as modulo interference factor notification, and power backoff only needs to notify the interference power or the power backoff factor, the power adjustment modes can also implicitly indicate through transmission of the interference information. For example, if the receiving end receives one or more complex signals, it determines that the current power adjustment mode is modulo, and if the receiving end receives one or more real signals, it determines that the current power adjustment mode is power backoff, and to ensure the accuracy of the determination, it may further compare whether the number of the received interference information matches the DMRS configuration information, that is, whether the number of the received interference information matches the number of the interference information corresponding to 2 and 4 DMRS ports in the CDM group.

It should be noted that the above definition of the modulo mark is only an example, and the specific value and meaning can be changed arbitrarily.

Compared with the first embodiment shown in fig. 7, the second embodiment shown in fig. 9 omits the notification of the threshold, and changes to explicitly or implicitly notify the DMRS power adjustment manner, so that the complexity of the receiving end can be reduced, and when the DMRS power adjustment manner is implicitly indicated, the signaling overhead is further reduced.

Compared with the prior art that the power backoff method is adopted to reduce the power increase of the non-linear precoding DMRS due to pre-interference reduction, in the second embodiment shown in fig. 9, in the present embodiment, the base station or the transmitting end selects the optimal DMRS power adjustment method by determining the interference power, and notifies the optimal DMRS power adjustment method to the terminal or the receiving end, and the terminal or the receiving end determines an effective DMRS transmission signal according to different DMRS power adjustment methods for channel estimation.

Optionally, since the DMRS is a known signal, when the power of the DMRS is adjusted by modulo, the following two points are different from each other: the DMRS does not need to perform inverse modulo operation at a receiving end to recover the original QAM signal; the DMRS is a QPSK signal, and the introduced module does not reduce the power of the effective transmission signal of the DMRS. Therefore, when the DMRS adopts the nonlinear precoding, the power can be adjusted modulo the DMRS configuration without considering the interference power. In the embodiment of the invention, when the data and the DMRS both adopt nonlinear precoding, the DMRS adopts modular power adjustment. Therefore, the transmitting end/base station may not need to transmit the threshold, the power adjustment identifier, and the like to the receiving end/terminal. Compared with the first embodiment and the second embodiment shown above, the power adjustment mode of the DMRS with the fixed nonlinear precoding is used as a modulus, so that the notification of a threshold or a power adjustment mode is omitted, and the signaling overhead is further reduced. Reference may be made specifically to the third embodiment shown in fig. 10. Wherein the content of the first and second substances,

s1001: the base station acquires a channel and acquires interference information of each layer according to the channel.

S1002: and the base station confirms the interference information of each layer of DMRS by combining the current DMRS configuration information.

S1003: the base station sends the interference information of the DMRS and/or the DMRS sequence information of other layers or other terminals to the terminal, and the terminal receives the interference information of the DMRS sent by the base station and/or the DMRS sequence information of other layers or other terminals.

S1004: and the base station performs nonlinear precoding on the data and the DMRS, wherein the DMRS is subjected to power adjustment in a mode of solving the modes.

S1005: and the base station sends the nonlinear precoded data and the DMRS to the terminal, and the terminal receives the nonlinear precoded data and the DMRS sent by the base station.

S1006: and the terminal determines an effective sending signal of the DMRS according to the interference information of the DMRS and/or DMRS sequence information of other layers or other terminals, estimates a channel by combining a receiving signal of the DMRS, balances data and completes data demodulation.

Compared with the prior art that the power backoff mode is adopted to reduce the power increase of the non-linear precoding DMRS due to the pre-interference subtraction, the third embodiment shown in fig. 10 reduces the power increase of the DMRS due to the pre-interference subtraction by the mode of power backoff, so that the transmission power of the DMRS can be effectively controlled when the interference power is too large, and a terminal or a receiving end determines an effective transmission signal according to the interference information and the like sent by the base station or the transmitting end, so as to be used for channel estimation. Compared with the embodiments shown in fig. 7 and fig. 9, the embodiment shown in fig. 10 omits the notification of the threshold or the power adjustment manner, thereby further reducing the signaling overhead.

Fig. 11 is a schematic diagram illustrating a possible logical structure of the wireless communication system, the first communication device, and the second communication device according to the embodiment of the present application. Wherein the first communication device 1100 comprises: a processing unit 1101 and a transmitting unit 1102. The second communication apparatus 1200 includes: a receiving unit 1201 and a processing unit 1202.

In a first implementation manner of the embodiment of the present invention, the processing unit 1101 is configured to perform interference pre-cancellation and power adjustment on a first reference signal to obtain a transmission signal, where when an interference power of the first reference signal is greater than or equal to a first preset threshold, the power adjustment manner is modulo; a sending unit 1102, configured to send the sending signal to the second communication device.

Optionally, when the interference power of the first reference signal is smaller than the first preset threshold, the power adjustment mode is power backoff.

Optionally, the sending unit 1102 is further configured to send the interference information of the first reference signal to the second communication device, where the interference information of the first reference signal is used by the second communication device to determine an effective sending signal of the first reference signal, and the effective sending signal is used by the second communication device to estimate a channel.

Optionally, the sending unit 1102 is further configured to send a sequence of a second reference signal to the second communication device, where the sequence of the second reference signal is used by the second communication device to determine the effective sending signal.

Optionally, if the power adjustment mode is modulo, the interference information includes an interference factor corresponding to the first reference signal; if the power adjustment mode is power backoff, the interference information includes a power backoff factor of the first reference signal.

Optionally, the sending unit 1102 is further configured to send the first preset threshold to the second communication device, where the first preset threshold is used by the second communication device to determine the power adjustment mode; or, sending a power adjustment mode identifier to the second communication device, where the power adjustment mode identifier is used to indicate the power adjustment mode.

A receiving unit 1201, configured to receive a transmission signal sent by a first communication device, where the transmission signal is obtained by the first communication device performing interference pre-cancellation and power adjustment on a first reference signal, and when an interference power of the first reference signal is greater than or equal to a first preset threshold, the power adjustment mode is modulo. A processing unit 1202, configured to estimate a channel according to a received signal of the first reference signal and an effective transmitted signal of the first reference signal.

Optionally, the receiving unit 1201 is further configured to receive, before the processing unit 1202 estimates a channel according to the received signal of the first reference signal and the transmitted signal, interference information of the first reference signal transmitted by the first communication device;

the processing unit 1202 is further configured to determine the effective transmission signal according to the interference information.

Optionally, the receiving unit 1201 is further configured to receive a sequence of a second reference signal sent by the first communication device before the processing unit 1202 estimates a channel according to the received signal of the first reference signal and the sent signal;

the processing unit 1202, configured to determine the effective transmission signal according to the interference information, includes:

and determining the effective sending signal according to the interference information and the sequence of the second reference signal.

Optionally, the receiving unit 1201 is further configured to receive the first preset threshold sent by the first communication device, where the first preset threshold is used by the second communication device to determine the power adjustment mode; or receiving a power adjustment mode identifier sent by the first communication device, where the power adjustment mode identifier is used to indicate the power adjustment mode.

In a second implementation manner of the embodiment of the present invention, the processing unit 1101 is configured to perform interference pre-cancellation and modulo calculation on a first reference signal to obtain a sending signal; a sending unit 1102, configured to send the sending signal to the second communication device.

Optionally, the interference information includes an interference factor corresponding to the first reference signal.

The second communication apparatus 1200 includes: a receiving unit 1201 and a processing unit 1202.

A receiving unit 1201, configured to receive a transmission signal sent by a first communication device, where the transmission signal is obtained by the first communication device performing interference pre-cancellation and modulo calculation on a first reference signal. A processing unit 1202, configured to estimate a channel according to a received signal of the first reference signal and an effective transmitted signal of the first reference signal.

Optionally, the first communication device may be a network device, and the second communication device may be a terminal.

It should be noted that for specific implementation of each unit in the first communication device 1100 and the second communication device 1200, reference may be made to the related description in the channel estimation method embodiments shown in fig. 6 to fig. 10, which is not repeated herein.

Referring to fig. 12, fig. 12 is a schematic diagram illustrating a structure of a communication chip provided in the present application. As shown in fig. 12, the communication chip 1300 may include: a processor 1301, and one or more interfaces 1302 coupled to the processor 1301. Wherein:

processor 1301 may be used to read and execute computer readable instructions. In particular, processor 1301 may include a controller, an operator, and a register. The controller is mainly responsible for instruction decoding and sending out control signals for operations corresponding to the instructions. The arithmetic unit is mainly responsible for executing fixed-point or floating-point arithmetic operation, shift operation, logic operation and the like, and can also execute address operation and conversion. The register is mainly responsible for storing register operands, intermediate operation results and the like temporarily stored in the instruction execution process. In a specific implementation, the hardware architecture of the processor 1301 may be an Application Specific Integrated Circuit (ASIC) architecture, a microprocessor without interlocked pipeline stage architecture (MIPS) architecture, an advanced reduced instruction set machine (ARM) architecture, or an NP architecture. Processor 1301 may be single core or multicore.

The interface 1302 may be used to input data to be processed to the processor 1301, and may output a processing result of the processor 1301 to the outside. In a specific implementation, the interface 1302 may be a general purpose input/output (GPIO) interface, and may be connected to a plurality of peripheral devices (e.g., a display (LCD), a camera (camara), a Radio Frequency (RF) module, etc.). The interface 1302 is connected to the processor 1301 via a bus 1303.

In this application, the processor 1301 may be configured to invoke, from the memory, an implementation program of the channel estimation method provided in one or more embodiments of the present application on the communication device side, and execute instructions included in the implementation program. The memory may be integrated with the processor 1301 or may be coupled to the communication chip 130 via the interface 1302. The interface 1302 may be used to output the results of the execution by the processor 1301. In this application, the interface 1302 may be specifically configured to output the decoding result of the processor 1301. For the channel estimation method provided in one or more embodiments of the present application, reference may be made to the foregoing embodiments, and details are not repeated here.

It should be noted that the functions corresponding to the processor 1301 and the interface 1302 may be implemented by hardware design, software design, or a combination of hardware and software, which is not limited herein.

The terms "first," "second," "third," and "fourth," etc. in the description and claims of this application and in the accompanying drawings are used for distinguishing between different objects and not for describing a particular order. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to only those steps or elements listed, but may alternatively include other steps or elements not listed, or inherent to such process, method, article, or apparatus.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above can be implemented by a computer program, which can be stored in a computer-readable storage medium, and when executed, can include the processes of the embodiments of the methods described above. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), a Random Access Memory (RAM), or the like.

The above embodiments are only intended to be illustrative of the embodiments of the present invention, and should not be construed as limiting the scope of the embodiments of the present invention, and any modifications, equivalent substitutions, improvements and the like made on the basis of the technical solutions of the embodiments of the present invention should be included in the scope of the embodiments of the present invention.

Claims

1. A method of channel estimation, comprising:

a first communication device performs interference pre-cancellation and power adjustment on a first reference signal to obtain a sending signal, wherein when the interference power of the first reference signal is greater than or equal to a first preset threshold, the power adjustment mode is modular, and when the interference power of the first reference signal is less than the first preset threshold, the power adjustment mode is power backoff;

the first communication device sends the sending signal to a second communication device; further comprising:

2. The method of claim 1, further comprising:

3. The method of claim 1, wherein if the power adjustment is modulo, the interference information comprises an interference factor corresponding to the first reference signal; if the power adjustment mode is power backoff, the interference information includes a power backoff factor of the first reference signal.

4. The method of any of claims 1 to 3, further comprising:

5. A method of channel estimation, comprising:

the method comprises the steps that a second communication device receives a sending signal sent by a first communication device, wherein the sending signal is obtained after the first communication device carries out interference pre-elimination and power adjustment on a first reference signal, when the interference power of the first reference signal is larger than or equal to a first preset threshold, the power adjustment mode is mode calculation, and when the interference power of the first reference signal is smaller than the first preset threshold, the power adjustment mode is power backoff;

the second communication device estimates a channel according to a received signal of the first reference signal and an effective transmitted signal of the first reference signal, wherein the effective transmitted signal is used for the second communication device to estimate the channel;

before estimating a channel according to the received signal of the first reference signal and the effective transmitted signal of the first reference signal, the second communication device further includes:

6. The method of claim 5, wherein before the second communication device estimates the channel according to the received signal of the first reference signal and the valid transmitted signal of the first reference signal, further comprising:

7. The method of claim 5, wherein if the power adjustment is modulo, the interference information comprises an interference factor corresponding to the first reference signal; if the power adjustment mode is power backoff, the interference information includes a power backoff factor of the first reference signal.

8. The method of any of claims 5 to 7, further comprising:

9. A communication device, characterized in that the communication device is a first communication device comprising means or a unit for performing the channel estimation method of any of claims 1 to 4.

10. A communication device, characterized in that the communication device is a second communication device comprising means or a unit for performing the channel estimation method of any of claims 5 to 8.

11. A communication system comprising a first communication device and a second communication device, the first communication device being the first communication device of claim 9, the second communication device being the second communication device of claim 10.