Precoding method and system for preventing environmental perception in device communication state

Abstract

The present application discloses a precoding method and system for preventing environmental perception in a device communication state, and relates to the field of wireless communication technology, including: obtaining the current environmental state; determining an initial codeword vector according to the current environmental state; in the channel estimation stage, precoding an initial pilot matrix based on the initial codeword vector to obtain a coded pilot matrix; sending the coded pilot matrix to a communication device end, so that the communication device end performs channel state estimation when receiving the receiving pilot matrix, obtains the perception probability performance and feeds back; in the data sending stage, determining the communication rate performance based on the channel state feature vector and the initial codeword vector; optimizing the initial codeword vector based on the perception probability performance and the communication rate performance to obtain a target codeword vector; updating the initial codeword vector through the target codeword vector to prevent the communication device end from performing environmental perception, and preventing it from perceiving the environmental situation without damaging the device communication.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a precoding method and system for preventing environmental perception in a device communication state. Background Art

[0002] In recent years, the technology of environmental situational awareness based on communication signals such as WiFi and millimeter waves for indoor dynamic detection of people and posture recognition has received more and more attention. Its basic principle is that human activities directly affect the indoor wireless multipath transmission environment, and the characteristic changes caused by the transmission of wireless signals in the environment reflect the physical environment status, human activities and other information. One of the main reasons why communication-based perception has received attention is the natural integration of perception and communication systems. Specifically, today's communication systems and equipment have perfect channel estimation functions. During the communication process, the system transceiver will continuously estimate the wireless channel state information (CSI) by transmitting and receiving known pilots. CSI reflects the changes in the amplitude and phase of the transmission signal caused by the wireless channel in a given environment. In recent years, more and more studies have shown that CSI can be directly reused to achieve the purpose of perception, and environmental situation information can be obtained by analyzing the static or dynamic change characteristics of the wireless channel. Perception is low-cost and easy to implement. Taking the WiFi system as an example, WiFi is currently the main network form for indoor scenes such as homes, enterprises and businesses. WiFi network equipment has initially become an excellent medium and carrier for indoor perception. Applications such as indoor environment monitoring, human health status and anomaly detection using commercial WiFi system CSI are emerging.

[0003] The development of technology and applications for communication devices to perceive the environment based on wireless channel characteristics has brought new problems in privacy and information security. Any communication device has the ability to obtain CSI. The owner of the communication device can use or disseminate the acquired CSI information for environmental state perception and reasoning, so as to achieve the purpose of detecting the number of people, movement trajectory, posture and gesture in indoor environments and even outdoor walls. This behavior and intention of extracting environmental information with the help of communication CSI is difficult to identify and discover, and it is difficult to know whether the perception information is extracted, maliciously disseminated or improperly used, thus posing a major threat to privacy security that is difficult to defend against. At present, the privacy and security issues caused by CSI for environmental information reasoning have received some research attention, but the response methods are very limited. The existing methods mainly interfere with the CSI estimation of the signal receiving device by adding random noise or randomly changing the signal phase, thereby interfering with perception. However, the existing defense and prevention methods for perception usually ignore the basic communication needs of the device. How to prevent the device from perceiving the environmental situation without damaging the communication is still an unresolved problem. Summary of the invention

[0004] The main purpose of the present application is to provide a precoding method and system for preventing environmental perception in a device communication state, aiming to solve the technical problem of how to prevent the device from perceiving the environmental situation without damaging the device communication.

[0005] To achieve the above object, the present application proposes a precoding method for preventing environmental perception in a device communication state, wherein the precoding method for preventing environmental perception in a device communication state is applied to a signal transmitting end, and the method includes:

[0006] Get the current environment status;

[0007] Determine an initial codeword vector according to the current environment state;

[0008] In the channel estimation stage, the initial pilot matrix is ​​precoded based on the initial codeword vector to obtain a coded pilot matrix;

[0009] The coded pilot matrix is ​​sent to a communication device end, so that the communication device end performs channel state estimation when receiving the received pilot matrix, obtains the perception probability performance and feeds back;

[0010] In the data transmission phase, the communication rate performance is determined based on the channel state feature vector and the initial codeword vector;

[0011] Optimizing the initial codeword vector based on the perception probability performance and the communication rate performance to obtain a target codeword vector;

[0012] The initial codeword vector is updated by using the target codeword vector to prevent the communication device from performing environmental perception.

[0013] In one embodiment, the step of determining the communication rate performance based on the channel state feature vector and the initial codeword vector in the data transmission phase includes:

[0014] In the data transmission phase, an equivalent channel state feature vector is determined based on the channel state feature vector and the initial codeword vector;

[0015] Performing beamforming on the equivalent channel state eigenvector to obtain beamforming code;

[0016] The communication rate performance is determined according to the beamforming code, the equivalent channel state feature vector and the initial codeword vector.

[0017] In one embodiment, the step of determining the communication rate performance according to the beamforming code, the equivalent channel state eigenvector and the initial codeword vector comprises:

[0018] Determine concatenated coding according to the beamforming coding and the initial codeword vector;

[0019] Normalizing the cascade code to obtain a normalized cascade code;

[0020] Obtain transmit power and complex Gaussian distribution variance;

[0021] The sum of the maximum achievable communication rates of the communication device under different environmental conditions is calculated according to the transmit power, the complex Gaussian distribution variance, the normalized cascade coding and the equivalent channel state eigenvector to obtain the communication rate performance.

[0022] In one embodiment, in the channel estimation stage, the step of precoding the initial pilot matrix based on the initial codeword vector to obtain the coded pilot matrix includes:

[0023] In the channel estimation stage, several groups of pilot vectors are obtained to obtain an initial pilot matrix;

[0024] Each pilot vector in the initial pilot matrix is ​​precoded by using the initial codeword vector to obtain a coded pilot matrix.

[0025] In one embodiment, the step of optimizing the initial codeword vector based on the perception probability performance and the communication rate performance to obtain a target codeword vector includes:

[0026] Obtain correct perception probability constraint threshold and preset optimization strategy;

[0027] Solving the perception probability performance and the communication rate performance by using the correct perception probability constraint threshold and the preset optimization strategy to obtain a solution result;

[0028] The initial codeword vector is optimized according to the solution result to obtain a target codeword vector.

[0029] In one embodiment, the step of determining the initial codeword vector according to the current environment state includes:

[0030] Determine the environmental state and corresponding channel state characteristics that need to be prevented from being perceived by the communication device end;

[0031] When the current environment state belongs to an environment state that needs to be prevented from being perceived by the communication device end, determining a corresponding target channel state feature;

[0032] An initial codeword vector is determined according to the target channel state characteristic.

[0033] In addition, to achieve the above purpose, the present application also proposes a precoding method for preventing environmental perception in a device communication state, wherein the precoding method for preventing environmental perception in a device communication state is applied to a communication device end, and the method includes:

[0034] When a coded pilot matrix sent by a signal transmitting end is detected, a receiving pilot matrix is ​​received, where the receiving pilot matrix is ​​a matrix to which random noise is added when the coded pilot matrix is ​​transmitted;

[0035] Perform channel state estimation based on the received pilot matrix to obtain perception probability performance;

[0036] The perceived probability performance is sent to the signal transmitting end, so that the signal transmitting end performs precoding based on the perceived probability performance and the determined communication rate performance.

[0037] In one embodiment, the step of performing channel state estimation based on the received pilot matrix to obtain the perception probability performance includes:

[0038] Obtaining an initial pilot matrix;

[0039] Perform channel state estimation based on the received pilot matrix and the initial pilot matrix to determine an estimated current environment state and an estimated equivalent channel state eigenvector;

[0040] A perception probability performance is obtained based on the received pilot matrix, the estimated current environment state and the estimated equivalent channel state eigenvector.

[0041] In one embodiment, the step of obtaining the perception probability performance based on the received pilot matrix, the estimated current environment state, and the estimated equivalent channel state eigenvector includes:

[0042] Determining a correct perception probability according to the received pilot matrix, the estimated current environment state, and the estimated equivalent channel state eigenvector;

[0043] Comparing the correct perception probability with a preset decision threshold to obtain a comparison result;

[0044] The perception probability performance is obtained according to the comparison result.

[0045] In addition, to achieve the above-mentioned purpose, the present application also proposes a precoding system for preventing environmental perception in the device communication state, the system including a signal transmitting end and a communication device end, the signal transmitting end executes the precoding method for preventing environmental perception in the device communication state as described above, and the communication device end executes the precoding method for preventing environmental perception in the device communication state as described above.

[0046] One or more technical solutions proposed in this application, a precoding method for preventing environmental perception in the device communication state is applied to the signal transmitting end, the method includes: obtaining the current environmental state; determining the initial codeword vector according to the current environmental state; in the channel estimation stage, precoding the initial pilot matrix based on the initial codeword vector to obtain the coded pilot matrix; sending the coded pilot matrix to the communication device end, so that the communication device end performs channel state estimation when receiving the receiving pilot matrix, obtains the perception probability performance and feedback; in the data sending stage, determines the communication rate performance based on the channel state feature vector and the initial codeword vector; optimizes the initial codeword vector based on the perception probability performance and the communication rate performance to obtain the target codeword vector; updates the initial codeword vector through the target codeword vector to prevent the communication device end from performing environmental perception. The method of this application can prevent the communication device from using CSI to perceive the environmental situation while supporting device communication, and protect the security of environmental privacy information while communicating. It includes the channel estimation stage, in which the transmitter performs privacy precoding on the pilot signal to resist perception, the estimation and correct probability of the equivalent CSI after encoding by the user communication device, the beamforming based on precoding and equivalent CSI by the transmitter in the data communication stage, and the information rate performance description of the user communication device. It solves the precoding design that supports user device communication while resisting perception, so as to prevent the user device from estimating and parsing environmental information with the help of communication CSI. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0048] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0049] Figure 1 This is a flow chart of a first embodiment of a precoding method for preventing environmental perception in a communication state of a device at a signal transmitting end according to the present application;

[0050] Figure 2 A schematic diagram of the communication system environment for this application;

[0051] Figure 3 A schematic diagram of anti-sensing communication precoding for applying a precoding method for preventing environmental perception in a communication state of a device at a signal transmitting end;

[0052] Figure 4This is a flow chart of a second embodiment of a precoding method for preventing environmental perception in a communication state of a device at a signal transmitting end according to the present application;

[0053] Figure 5 This is a flowchart of a first embodiment of a precoding method for preventing environment perception in a device communication state applied to a communication device end of the present application;

[0054] Figure 6 This is a flow chart of a second embodiment of a precoding method for preventing environment perception in a device communication state applied to a communication device end of the present application.

[0055] The purpose, features and advantages of this application will be further described in conjunction with the embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0056] It should be understood that the specific embodiments described herein are only used to explain the technical solutions of the present application and are not used to limit the present application.

[0057] In order to better understand the technical solution of the present application, a detailed description will be given below in conjunction with the accompanying drawings and specific implementation methods.

[0058] The main solution of the embodiment of the present application is: a precoding method for preventing environmental perception in the communication state of the device is applied to the signal transmitting end, and the method includes: obtaining the current environmental state; determining an initial codeword vector according to the current environmental state; in the channel estimation stage, precoding the initial pilot matrix based on the initial codeword vector to obtain a coded pilot matrix; sending the coded pilot matrix to the communication device end, so that the communication device end performs channel state estimation when receiving the receiving pilot matrix, obtains the perception probability performance and feeds back; in the data sending stage, determining the communication rate performance based on the channel state feature vector and the initial codeword vector; optimizing the initial codeword vector based on the perception probability performance and the communication rate performance to obtain a target codeword vector; updating the initial codeword vector by the target codeword vector to prevent the communication device end from performing environmental perception.

[0059] The existing technology mainly interferes with the CSI estimation of the signal receiving device by adding random noise or randomly changing the signal phase, thereby interfering with the perception. However, it ignores the basic communication requirements of the equipment, resulting in poor communication effect.

[0060] This application provides a solution for the environmental situation information that the communication network service deployer (SP, service provider) needs to protect. The signal transmitting end, such as the network access point (AP, access point) device such as base station, WiFi and hotspot, adds precoding processing to the pilot signal and data transmission in the two stages of communication system channel estimation and data transmission. Among them, in the channel estimation stage, the transmitting end manually controls and changes the CSI result of the channel estimation of the receiving device by encoding the pilot, reducing the ability of the receiving device to obtain CSI for perception and reasoning of environmental situation information; in the data transmission stage, the transmitting end performs traditional coding processing on the data based on the pilot precoding, thereby supporting device communication while preventing the device from using CSI to perceive environmental information.

[0061] It should be noted that the execution subject of this embodiment may be a computing service device with data processing, network communication and program running functions, such as a tablet computer, a personal computer, a mobile phone, etc., or an electronic device, a signal transmitter or a communication device that can realize the above functions. The following takes the signal transmitter or the communication device as an example to illustrate this embodiment and the following embodiments.

[0062] Based on this, the embodiment of the present application provides a precoding method for preventing environmental perception in a device communication state, referring to Figure 1 , Figure 1 This is a flow chart of a first embodiment of a precoding method for preventing environmental perception in a communication state of a device at a signal transmitting end according to the present application.

[0063] In this embodiment, the precoding method for preventing environment perception in a communication state of a device at a signal transmitting end includes steps S10 to S70:

[0064] Step S10: Get the current environment status.

[0065] It should be noted that the current environment state may be the environment state of the system, which may include a manned state or an unmanned state, such as Figure 2 As shown, Figure 2 This is a schematic diagram of the communication system environment. The presence of a person at a certain position in the system environment, the movement and posture of the person in the environment, etc. directly affect the amplitude, phase and other characteristics of the wireless channel, namely, the CSI characteristics. The signal will undergo diffraction, reflection, scattering, etc.; the implementation of the communication process includes two stages: channel estimation and data communication. In the channel estimation stage, the transmitter transmits a known pilot signal, and the user communication device (UD) obtains the CSI characteristics based on the reception of the pilot. The user communication device performs symbol detection for traditional communications and environmental detection for perception multiplexing.

[0066] Step S20: Determine an initial codeword vector according to the current environment state.

[0067] In a specific implementation, in order to prevent the user communication device from using the communication channel state characteristic vector to perceive the environment, the signal transmitting end may first determine the environmental situation to be protected and the corresponding channel state characteristic information.

[0068] It should be noted that after the corresponding channel state characteristic information is determined, the corresponding codeword vector can be selected according to the channel state characteristic information to obtain an initial codeword vector.

[0069] The initial codeword vector is a coding vector for precoding a publicly known pilot signal. In the channel estimation phase, the signal transmitter precodes the publicly known pilot signal and changes the CSI estimation result of the user communication device by changing the pilot amplitude and phase. The precoded codeword is private to the signal transmitter.

[0070] In a feasible implementation, step S20 may include steps A11 to A13:

[0071] Step A11: Determine the environmental state and corresponding channel state characteristics that need to be prevented from being perceived by the communication device.

[0072] It should be understood that the environmental state that needs to be prevented from being perceived by the communication device, that is, the environmental situation that needs to be protected, can be the environmental state of sensing whether there is someone in a special location in the environment. The corresponding channel state characteristics are different under different environmental states.

[0073] The signal transmitter can obtain the channel state characteristics of the scenario to be protected in advance through pre-training, machine learning, ray tracing channel simulation, etc.

[0074] Step A12: When the current environment state is an environment state that needs to be prevented from being perceived by the communication device, a corresponding target channel state feature is determined.

[0075] In a specific implementation, it can be determined whether the current environmental state belongs to an environmental scenario that requires privacy protection. If the current environmental state belongs to an environmental scenario that requires privacy protection, that is, it is an environmental state that needs to be prevented from being perceived by the communication device, then the target channel state characteristics corresponding to the current environmental state can be determined.

[0076] For example, if there is no one in a special location in the environment, it is marked as state 0 to indicate that the AP The complex-valued channel CSI eigenvector from the root transmit antenna to UD is ; The special location of the environment is recorded as state 1, Indicates that AP The complex-valued channel CSI eigenvector from the root transmit antenna to UD is .

[0077] Step A13: Determine an initial codeword vector according to the target channel state characteristics.

[0078] It should be noted that after determining the target channel state characteristics, the corresponding initial codeword vector can be determined. For example, the target channel state characteristics are , then the corresponding initial codeword vector is .

[0079] When the environment is in state 0: the signal transmitter uses a complex-valued codeword vector right The amplitude and phase of the signal transmitted by the root antenna are controlled. represents the transpose, where It is a plural number, indicating the environment state 0. Amplitude and phase control of the root antenna signal.

[0080] When the environment is in state 1: the signal transmitter uses a complex-valued codeword vector right The amplitude and phase of the signal sent by the root antenna are controlled. Indicates the environment state 1 Amplitude and phase control of the root antenna signal.

[0081] Step S30: In the channel estimation stage, the initial pilot matrix is ​​precoded based on the initial codeword vector to obtain a coded pilot matrix.

[0082] It can be understood that after the initial codeword vector is determined, the initial pilot matrix can be precoded by the initial codeword vector in the channel estimation stage to obtain a coded pilot matrix. Only the AP knows. Without loss of generality, when the environment state is conditions, .

[0083] In traditional AP-UD communication, the signal transmitter periodically sends a pilot signal known to both parties, and the communication device receives the CSI feature based on the pilot signal. Continuously estimate and perform channel equalization and data symbol decision detection based on this information. In order to prevent the communication device from distinguishing the channel state feature vector and The signal sending end uses the following method to infer the presence and absence of people in the environment: Figure 3 The precoding shown in FIG. 1 performs the same privacy coding process on the pilot and data in the channel estimation and data communication stages, respectively. Figure 3As shown in the figure, in the channel estimation stage, the transmitter (AP) adds anti-UD perception precoding, which is private to the signal transmitter AP. After encoding the channel state eigenvector, it is sent to the user communication device (UD). The user communication device receives a receiving pilot matrix with added noise. At this time, the user communication device estimates the channel state eigenvector based on the receiving pilot matrix. In the data communication stage, the signal transmitter (AP) implements spatial diversity multiplexing through beamforming coding and anti-UD perception precoding to support the communication of user devices.

[0084] In a feasible implementation, step S30 may include steps A21-A22:

[0085] Step A21: In the channel estimation stage, several groups of pilot vectors are obtained to obtain an initial pilot matrix.

[0086] It should be noted that in the channel estimation stage, the signal transmitter will send N groups of coded pilots. Therefore, N groups of pilot vectors can be obtained, using the matrix Represents, that is, the initial pilot matrix, yes dimensional complex-valued matrix, where yes The row is a complex-valued column vector, representing the Group The pilot vector transmitted by the root antenna; the pilot matrix It is known to the signal transmitting end and the communication device end.

[0087] Step A22: pre-encode each pilot vector in the initial pilot matrix using the initial codeword vector to obtain a coded pilot matrix.

[0088] In a specific implementation, when the AP uses the initial codeword vector Precode the pilot to get the coded pilot matrix, which is the pilot matrix actually sent. .

[0089] In the channel estimation phase, the signal transmitter precodes the publicly known pilot signal and changes the CSI estimation result of the UD by changing the pilot amplitude and phase. The precoding codeword is private to the AP. In the data transmission phase, the AP performs traditional data transmission beamforming based on the changed CSI while retaining the pilot precoding to achieve spatial diversity multiplexing and support the communication of user equipment.

[0090] Step S40: sending the coded pilot matrix to the communication device end, so that the communication device end performs channel state estimation when receiving the received pilot matrix, obtains the perception probability performance and feeds back.

[0091] In a specific implementation, random noise is added during the process of sending the coded pilot matrix to the communication device end, so the communication device end receives the received pilot matrix. Indicates UD status in different environments In the case of the received pilot signal, It is expressed as:

[0092]

[0093] in, is the Hadamard product, is a Gaussian white noise sample with the following characteristics: ,use Represents noise sampling The mean is 0 and the variance is The complex Gaussian distribution refers to a Gaussian distribution with a real part and an imaginary part, and is often used to describe the probability distribution of random variables with complex values.

[0094] Because the codeword used by AP The user equipment is unknown, and the UD can only Therefore, the communication device can estimate the channel state, thereby obtaining the perception probability performance and feeding it back to the signal sending end.

[0095] Perception probability performance estimates the environment state for the communication device When the corresponding estimated equivalent channel state eigenvector is The probability of perception includes the UD’s perception of the environment state. The probability of correct perception or incorrect perception.

[0096] Step S50: During the data transmission phase, the communication rate performance is determined based on the channel state feature vector and the initial codeword vector.

[0097] It should be noted that during the data transmission phase, the signal transmitter will retain the precoding Traditional data encoding is performed on this basis, also known as beamforming, so beamforming can be performed according to the channel state feature vector and the initial codeword vector to determine the communication rate performance.

[0098] The communication rate performance is the sum of the maximum achievable communication rates of the communication device end UD under different environmental conditions.

[0099] Step S60: Optimizing the initial codeword vector based on the perception probability performance and the communication rate performance to obtain a target codeword vector.

[0100] It should be noted that the AP anti-sensing precoding can be constructed based on the perception probability performance and communication rate performance of the communication device end. The optimization problem is solved to find the precoding codeword with the maximum communication rate under the condition of correct perception probability of the communication device end, so as to obtain the target codeword vector.

[0101] In a feasible implementation, step S60 may include steps A31 to A33:

[0102] Step A31: Obtain the correct perception probability constraint threshold and preset optimization strategy.

[0103] It should be noted that the correct perception probability constraint threshold does not exceed a threshold value The preset optimization strategy may be an optimization theory method such as alternating optimization (AO) or Lagrange multiplier method, or other optimization methods.

[0104] Step A32: Solving the perception probability performance and the communication rate performance by using the correct perception probability constraint threshold and the preset optimization strategy to obtain a solution result.

[0105] In a specific implementation, the optimized precoding design problem can be constructed according to the correct perception probability constraint threshold, as follows:

[0106]

[0107]

[0108] in, For the communication rate performance, In order to perceive the probability performance, the above formula can be solved by using a preset optimization strategy to obtain the solution result, which is the optimal .

[0109] Step A33: Optimize the initial codeword vector according to the solution result to obtain a target codeword vector.

[0110] In a specific implementation, an optimal codeword vector may be obtained according to the solution result, and thus the initial codeword vector may be optimized based on the solution result to obtain a target codeword vector.

[0111] Step S70: updating the initial codeword vector by using the target codeword vector to prevent the communication device from performing environment perception.

[0112] In a specific implementation, the initial codeword vector may be updated to a target codeword vector, so that the target codeword vector may be used for re-precoding, thereby preventing the communication device from sensing the communication environment.

[0113] This embodiment provides a precoding method for preventing environmental perception in the communication state of a device, which is applied to the signal transmitting end, and the method includes: obtaining the current environmental state; determining the initial codeword vector according to the current environmental state; in the channel estimation stage, precoding the initial pilot matrix based on the initial codeword vector to obtain the coding pilot matrix; sending the coding pilot matrix to the communication device end, so that the communication device end performs channel state estimation when receiving the receiving pilot matrix, obtains the perception probability performance and feedback; in the data sending stage, determines the communication rate performance based on the channel state feature vector and the initial codeword vector; optimizes the initial codeword vector based on the perception probability performance and the communication rate performance to obtain the target codeword vector; updates the initial codeword vector through the target codeword vector to prevent the communication device end from performing environmental perception. The method of the present application can prevent the device from using CSI to perceive the environmental situation while supporting device communication, and protect the security of environmental privacy information while communicating. It includes the channel estimation stage, in which the transmitter performs privacy precoding on the pilot signal to resist perception, the estimation and correct probability of the equivalent CSI after encoding by the user communication device, the beamforming based on precoding and equivalent CSI by the transmitter in the data communication stage, and the information rate performance description of the user communication device. It solves the precoding design that supports user device communication while resisting perception, so as to prevent the user device from estimating and parsing environmental information with the help of communication CSI.

[0114] Based on the first embodiment of the present application applied to the signal transmitting end, in the second embodiment of the present application applied to the signal transmitting end, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction, and will not be repeated in the following. Figure 4 , step S50 includes steps S501 to S503:

[0115] Step S501: In the data transmission phase, an equivalent channel state characteristic vector is determined based on the channel state characteristic vector and the initial codeword vector.

[0116] It should be noted that, in the data transmission phase, the channel state feature vector and the initial codeword vector Determine the equivalent channel state eigenvector. Equivalent channel state eigenvector .

[0117] Step S502: performing beamforming on the equivalent channel state eigenvector to obtain beamforming code.

[0118] In a specific implementation, the signal transmitter will retain the precoding in the data transmission stage. Traditional data encoding is performed based on the equivalent channel state eigenvector, also known as beamforming. , thereby achieving spatial diversity multiplexing.

[0119] Beamforming coding uses complex-valued vectors Represents the state of the environment In this case, the signal transmitting antenna beamforming vector, taking the classic maximum ratio transmission (MRT) beamforming as an example, when the equivalent channel state eigenvector is When , the beamforming vector that maximizes the Shannon information rate is , represents the conjugate transpose.

[0120] Step S503: Determine the communication rate performance according to the beamforming coding, the equivalent channel state eigenvector and the initial codeword vector.

[0121] In a specific implementation, the beamforming coding may be used , the equivalent channel state feature vector And the initial codeword vector Determines communication rate performance.

[0122] In a feasible implementation, step S503 may include: determining the cascade code based on the beamforming code and the initial codeword vector; normalizing the cascade code to obtain a normalized cascade code; obtaining the transmit power and the complex Gaussian distribution variance; calculating the sum of the maximum achievable communication rates of the communication device under different environmental states based on the transmit power, the complex Gaussian distribution variance, the normalized cascade code and the equivalent channel state eigenvector to obtain the communication rate performance.

[0123] It should be noted that the encoding effect of AP on data transmission is , that is, cascade coding, which can be obtained by beamforming coding and initial codeword vector calculation.

[0124] In the specific implementation, since the AP transmission power is limited, the given transmission power is In the case of , the cascade code can be normalized, that is, , and obtain the normalized cascade code.

[0125] It should be noted that the transmission power P , complex Gaussian distribution variance , Normalized Cascade Coding and the equivalent channel state eigenvector Calculate the sum of the maximum achievable communication rates of the communication device under different environmental conditions, and use It represents the sum of the maximum achievable communication rates of UD under the above two environmental conditions. According to Shannon's theorem, It can be calculated as:

[0126]

[0127] in, represents the Euclidean norm.

[0128] In the data transmission stage, this embodiment determines an equivalent channel state characteristic vector based on the channel state characteristic vector and the initial codeword vector; combines the acquired channel state characteristic vector with the initial codeword vector to determine an equivalent channel state characteristic vector. This can better adapt to the current channel conditions and provide an accurate reference for subsequent beamforming; beamforming is performed on the equivalent channel state characteristic vector to obtain beamforming coding. Through beamforming, the signal is transmitted to the target user in a direction, reducing the scattering and interference of the signal in other directions, thereby improving the signal strength; the communication rate performance is determined based on the beamforming coding, the equivalent channel state characteristic vector and the initial codeword vector. Beamforming reduces the waste of signal energy and reduces interference, so that the signal strength at the target user is higher, thereby improving the data transmission rate.

[0129] Based on this, the embodiment of the present application provides a precoding method for preventing environmental perception in a device communication state, referring to Figure 5 , Figure 5 This is a flow chart of a first embodiment of a precoding method for preventing environment perception in a device communication state applied to a communication device end of the present application.

[0130] In this embodiment, the precoding method for preventing environment perception in a device communication state applied to a communication device includes steps S41 to S43:

[0131] Step S41: when the coded pilot matrix sent by the signal transmitting end is detected, a receiving pilot matrix is ​​received, where the receiving pilot matrix is ​​a matrix to which random noise is added when the coded pilot matrix is ​​transmitted.

[0132] It should be noted that since the coded pilot matrix is , and the signal transmitter sends Afterwards, random noise will be added during the signal transmission process. Therefore, the pilot matrix received by the communication device is a received pilot matrix, that is, a coded pilot matrix with random noise added. The random noise can be Gaussian white noise or other noise, which is not limited in this embodiment.

[0133] Step S42: performing channel state estimation based on the received pilot matrix to obtain perception probability performance.

[0134] It should be noted that due to the signal receiving end using The user equipment is unknown, and the signal receiving end can only To estimate, use Indicates the environment status after AP precoding The equivalent CSI in this case is obtained, thereby obtaining the perceived probability performance.

[0135] Step S43: Send the perception probability performance to the signal transmitting end, so that the signal transmitting end performs precoding based on the perception probability performance and the determined communication rate performance.

[0136] In a specific implementation, the perception probability performance may be sent to the signal transmitting end, so that the signal transmitting end performs precoding through the perception probability performance and the determined communication rate performance, thereby preventing the communication device end from performing environmental perception.

[0137] In this embodiment, when the coded pilot matrix sent by the signal transmitting end is detected, a receiving pilot matrix is ​​received, and the receiving pilot matrix is ​​a matrix to which random noise is added when the coded pilot matrix is ​​transmitted; channel state estimation is performed based on the receiving pilot matrix to obtain perception probability performance; the perception probability performance is sent to the signal transmitting end so that the signal transmitting end performs precoding based on the perception probability performance and the determined communication rate performance. The receiving end performs channel state estimation based on the received pilot matrix to obtain the perception probability performance. Channel state estimation is achieved by comparing the known pilot signal sent and the received signal. The perception probability performance reflects the accurate perception degree of the receiving end to the channel state, including information such as channel attenuation and phase offset. By processing and analyzing the receiving pilot matrix, the channel state can be estimated more accurately. Accurate channel state estimation is crucial for subsequent signal processing and optimization, and can provide more reliable information for the signal transmitting end for more efficient signal transmission. After the perception probability performance is sent to the signal transmitting end, the transmitting end can perform precoding based on this information and the determined communication rate performance. Precoding is a technology that processes signals at the transmitting end. It adjusts the phase and amplitude of the signal so that the signal can be better decoded at the receiving end. Precoding can optimize the signal transmission method based on the channel state and perception probability performance, so that the signal-to-noise ratio at the receiving end is higher, thereby improving the communication rate performance.

[0138] Based on the first embodiment of the present application applied to the communication device side, in the second embodiment of the present application applied to the communication device side, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction, and will not be repeated in the following. Figure 6 , step S42 includes steps S421 to S423:

[0139] Step S421: Acquire an initial pilot matrix.

[0140] In a specific implementation, the initial pilot matrix is .

[0141] Step S422: performing channel state estimation based on the received pilot matrix and the initial pilot matrix, and determining an estimated current environment state and an estimated equivalent channel state eigenvector.

[0142] It can be understood that the received pilot matrix And the initial pilot matrix X is used to estimate the channel state. Considering UD, the classical least squares method is used for channel estimation. The result is When UD receives the pilot vector When the estimated equivalent channel state feature vector under different environmental conditions is Calculated as:

[0143]

[0144] Consider that UD continuously estimates CSI and successfully distinguishes and . Then when UD receives a new set of pilot vector, it can perform hypothesis testing on the current state of the environment. Indicates the environmental status Corresponding CSI estimation When UD receives the pilot signal vector The probability of , which is a Gaussian distribution, is expressed as ,in represents the Euclidean norm.

[0145] Step S423: obtaining the perception probability performance based on the received pilot matrix, the estimated current environment state and the estimated equivalent channel state eigenvector.

[0146] It should be noted that the current environment state can be estimated based on the received pilot matrix y And the estimated equivalent channel state eigenvector Get the perceived probability performance.

[0147] In a feasible implementation, step S423 may include:

[0148] Determining a correct perception probability according to the received pilot matrix, the estimated current environment state, and the estimated equivalent channel state eigenvector;

[0149] Comparing the correct perception probability with a preset decision threshold to obtain a comparison result;

[0150] The perception probability performance is obtained according to the comparison result.

[0151] It should be noted that according to the maximum likelihood estimation and Neyman-Pearson detection theory, the perception mathematical model is:

[0152]

[0153] in is the decision threshold. If the maximum likelihood ratio is greater than the threshold, UD determines the current environment state as , otherwise, the current environment state is considered to be .

[0154] Taking the logarithm operation of the above decision expression, the perception decision is simplified to be based on the following statistical variables The equivalent decision is:

[0155]

[0156] in Based on The decision threshold of exist and Under the environmental state, the degrees of freedom are The noncentrality parameter of F distribution of UD perception environment state The probability of correct perception is expressed as :

[0157]

[0158]

[0159] UD perceives the state of the environment The probability of false perception is expressed as , defined as UD determines the decision threshold according to the principle of minimum error probability , the threshold value to be set can be solved as Correspondingly, the correct perception probability of UD can be quantitatively calculated as:

[0160]

[0161] in Degree of freedom The noncentral parameters are The complementary cumulative distribution function of the F-distributed random variable can be calculated by the above description to obtain the UD perception probability performance .

[0162] This embodiment obtains an initial pilot matrix; performs channel state estimation based on the received pilot matrix and the initial pilot matrix, determines an estimated current environment state and an estimated equivalent channel state eigenvector; obtains the perception probability performance based on the received pilot matrix, the estimated current environment state and the estimated equivalent channel state eigenvector, and through accurate channel state estimation and perception probability performance calculation, the bit error rate of the signal during transmission can be reduced, and through real-time channel state estimation and perception probability performance calculation, the channel change can be quickly responded to, so that the communication system can maintain stable performance in a complex dynamic channel environment.

[0163] It should be noted that the above examples are only used to understand the present application and do not constitute a limitation on the precoding method for preventing environmental perception in the communication state of the device of the present application. More forms of simple transformations based on this technical concept are all within the scope of protection of the present application.

[0164] The present application also provides a precoding system for preventing environmental perception in a device communication state, the precoding system for preventing environmental perception in a device communication state comprises a signal transmitting end and a communication device end, the signal transmitting end executes the precoding method for preventing environmental perception in a device communication state as described above, and the communication device end executes the precoding method for preventing environmental perception in a device communication state as described above.

[0165] The precoding system for preventing environmental perception in the device communication state provided by the present application adopts the precoding method for preventing environmental perception in the device communication state in the above-mentioned embodiment, which can solve the technical problem of how to prevent the device from perceiving the environmental situation without damaging the device communication. Compared with the prior art, the beneficial effects of the precoding system for preventing environmental perception in the device communication state provided by the present application are the same as the beneficial effects of the precoding method for preventing environmental perception in the device communication state provided by the above-mentioned embodiment, and the other technical features of the precoding system for preventing environmental perception in the device communication state are the same as the features disclosed in the above-mentioned embodiment method, which will not be repeated here.

[0166] The above descriptions are only some embodiments of the present application, and are not intended to limit the patent scope of the present application. All equivalent structural changes made using the contents of the present application specification and drawings under the technical concept of the present application, or direct / indirect applications in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A precoding method for preventing environmental perception in a device communication state, characterized in that: The precoding method for preventing environment perception in a device communication state is applied to a signal transmitting end, and the method includes: Get the current environment status; Determine an initial codeword vector according to the current environment state; In the channel estimation stage, the initial pilot matrix is ​​precoded based on the initial codeword vector to obtain a coded pilot matrix; The coded pilot matrix is ​​sent to the communication device end, so that the communication device end performs channel state estimation when receiving the receiving pilot matrix, obtains the perception probability performance and feeds back the performance, wherein the perception probability performance is the probability of the communication device receiving the pilot signal vector when the communication device end estimates the estimated equivalent channel state feature vector corresponding to the environmental state, and the perception probability performance includes the correct perception probability or the incorrect perception probability of the communication device perceiving the environmental state; In the data transmission phase, an equivalent channel state feature vector is determined based on the channel state feature vector and the initial codeword vector; Performing beamforming on the equivalent channel state eigenvector to obtain beamforming code; Determining communication rate performance according to the beamforming code, the equivalent channel state eigenvector and the initial codeword vector; Obtain correct perception probability constraint threshold and preset optimization strategy; Solving the perception probability performance and the communication rate performance by using the correct perception probability constraint threshold and the preset optimization strategy to obtain a solution result; Optimizing the initial codeword vector according to the solution result to obtain a target codeword vector; The initial codeword vector is updated by using the target codeword vector to prevent the communication device from performing environmental perception.

2. The method according to claim 1, characterized in that The step of determining the communication rate performance according to the beamforming code, the equivalent channel state eigenvector and the initial codeword vector comprises: Determine concatenated coding according to the beamforming coding and the initial codeword vector; Normalizing the cascade code to obtain a normalized cascade code; Obtain transmit power and complex Gaussian distribution variance; The sum of the maximum achievable communication rates of the communication device under different environmental conditions is calculated according to the transmit power, the complex Gaussian distribution variance, the normalized cascade coding and the equivalent channel state eigenvector to obtain the communication rate performance.

3. The method according to claim 1, characterized in that The step of precoding the initial pilot matrix based on the initial codeword vector to obtain the coded pilot matrix in the channel estimation stage includes: In the channel estimation stage, several groups of pilot vectors are obtained to obtain an initial pilot matrix; Each pilot vector in the initial pilot matrix is ​​precoded by using the initial codeword vector to obtain a coded pilot matrix.

4. The method according to claim 1, characterized in that The step of determining the initial codeword vector according to the current environment state comprises: Determine the environmental state and corresponding channel state characteristics that need to be prevented from being perceived by the communication device end; When the current environment state belongs to an environment state that needs to be prevented from being perceived by the communication device end, determining a corresponding target channel state feature; An initial codeword vector is determined according to the target channel state characteristic.

5. A precoding method for preventing environmental perception in a device communication state, characterized in that: The precoding method for preventing environment perception in a device communication state is applied to a communication device end, and the method includes: When a coded pilot matrix sent by a signal transmitting end is detected, a receiving pilot matrix is ​​received, where the receiving pilot matrix is ​​a matrix to which random noise is added when the coded pilot matrix is ​​transmitted; Perform channel state estimation based on the received pilot matrix to obtain perception probability performance, where the perception probability performance is the probability that the communication device receives the pilot signal vector when the communication device estimates the equivalent channel state feature vector corresponding to the environmental state, and the perception probability performance includes the correct perception probability or the incorrect perception probability of the communication device perceiving the environmental state; The perception probability performance is sent to the signal transmitting end so that the signal transmitting end performs precoding based on the perception probability performance and the determined communication rate performance, and the communication rate performance is the sum of the maximum achievable communication rates of the communication device end under different environmental conditions.

6. The method according to claim 5, characterized in that The step of performing channel state estimation based on the received pilot matrix to obtain the perception probability performance comprises: Obtaining an initial pilot matrix; Perform channel state estimation based on the received pilot matrix and the initial pilot matrix to determine an estimated current environment state and an estimated equivalent channel state eigenvector; A perception probability performance is obtained based on the received pilot matrix, the estimated current environment state and the estimated equivalent channel state eigenvector.

7. The method according to claim 6, characterized in that The step of obtaining the perception probability performance based on the received pilot matrix, the estimated current environment state and the estimated equivalent channel state eigenvector comprises: Determining a correct perception probability according to the received pilot matrix, the estimated current environment state, and the estimated equivalent channel state eigenvector; Comparing the correct perception probability with a preset decision threshold to obtain a comparison result; The perception probability performance is obtained according to the comparison result.

8. A precoding system for preventing environmental perception in a device communication state, characterized in that: The system includes a signal transmitting end and a communication device end, wherein the signal transmitting end executes a precoding method for preventing environmental perception in a device communication state as described in any one of claims 1 to 4, and the communication device end executes a precoding method for preventing environmental perception in a device communication state as described in any one of claims 5 to 7.

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