# Signal transmission method and device and electronic equipment

## A signal transmission and signal technology, applied in transmission systems, radio transmission systems, electrical components, etc., can solve the problem of low effective signal performance

Active Publication Date: 2020-06-19

BEIJING UNIV OF POSTS & TELECOMM

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## AI-Extracted Technical Summary

### Problems solved by technology

[0005] The purpose of the embodiments of the present invention is to provide a signal transmission method, device, electronic equipment, and storage ...

### Method used

Adopt the method that the embodiment of the present invention provides, through the relational expression that needs to satisfy between the pre-established symbol vector and the disturbance vector, and the disturbance vector that satisfies the relational expression between the symbol vector to be coded, as the target disturbance vector, and then after using the target perturbation vector and precoding matrix to precode the symbol vector to be coded to obtain the signal to be transmitted, the vector to be transmitted can be directly transmitted, that is, the energy of the transmitting end can be used to transmit the effective signal without transmission. artificial noise; further, the receiving end receives the signal sent by the sending end without artificial noise, thereby improving the performance of receiving effective signals at the receiving end. Moreover, by adding the target perturbation vector at the sending end, the equivalent noise intensity at the receiving end can be effectively reduced, thereby further improving the performance of receiving effective signals at the receiving end.

[0119] Adopt the method provided by the embodiment of the present invention, through the relational expression that needs to be satisfied between the pre-established symbol vector and the disturbance vector, and the disturbance vector that satisfies the relational expression between the symbol vector to be encoded, as the target disturbance Vector, and then after using the target disturbance vector to precode the coded symbol vector to obtain the signal to be transmitted, the vector to be transmitted can be directly transmitted, that is, the energy of the transmitting end can be used to transmit the effective signal without transmitting artificial noise that has nothing to do with the effective signal; Furthermore, the signal sent by the sending end no longer contains artificial noise when the receiving end receives it, thereby improving the performance of receiving effective signals at the receiving end. Moreover, by adding the target perturbation vector at the sending end, the equivalent noise intensity at the receiving end can be effectively reduced, thereby improving the performance of receiving effective signals at the receiving end.

[0124] Using the method provided by the embodiment of the present invention, after receiving the signal sent by the sending end device, by using the relationship between the symbol vector and the disturbance vector established based on the spherical decoding parameters and the precoding matrix In the multiple modulo mode, the received signal is subjected to multiple modulo operation to obtain the signal to be demodulated, and further, the signal to be demodulated can be demodulated to obtain the received bit information stream. Since all the energy at the sending end can be used to transmit effective signals, there is no need to transmit artificial noise that has nothing to do with the effective signal; furthermore, the signal sent by the sending end at the receiving end does not contain artificial noise, thereby improving the reception of the receiving end. Effective signal performance. Moreover, the target perturbation vector added by the transmitting end can effectively reduce the equivalent noise intensity of the receiving end, thereby further improving the performance of receiving effective signals at the receiving end.

[0151] Using the method provided ...

## Abstract

The embodiment of the invention provides a signal transmission method and device and electronic equipment, and the method comprises the steps: carrying out the quadrature amplitude modulation of a to-be-transmitted bit information flow, and obtaining a to-be-coded symbol vector; on the basis of a pre-established relational expression needing to be met between a symbol vector and a disturbance vector, the disturbance vector meeting the relational expression with the symbol vector to be coded is determined to serve as a target disturbance vector, and the relational expression is the relational expression between the symbol vector and the disturbance vector established on the basis of the sphere decoding parameters and the precoding matrix; pre-coding the symbol vector to be coded by using the target disturbance vector to obtain a to-be-transmitted signal; and transmitting the to-be-transmitted signal. By adopting the method provided by the embodiment of the invention, the energy of the sending end can be completely used for transmitting effective signals without transmitting artificial noise irrelevant to the effective signals; furthermore, the signals received by the receiving end and sent by the sending end do not contain artificial noise any more, and the performance of receiving effective signals by the receiving end is improved.

Application Domain

Amplitude-modulated carrier systemsRadio transmission

Technology Topic

TelecommunicationsQuadrature amplitude modulation +6

## Image

## Examples

- Experimental program(1)

### Example Embodiment

[0094] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.

[0095] The embodiment of the invention discloses a signal transmission method, which is applied to a sending end device, such as figure 1 As shown, the following steps can be included:

[0096] Step 101: Perform quadrature amplitude modulation on the bit information stream to be transmitted to obtain a symbol vector to be coded.

[0097] Step 102, based on the pre-established relationship between the symbol vector and the disturbance vector that needs to be satisfied, determine the disturbance vector that satisfies the relationship with the symbol vector to be coded, as the target disturbance vector, and the relationship is: based on the sphere decoding parameter The relationship between the symbol vector established by the precoding matrix and the disturbance vector.

[0098] Step 103: Precoding the symbol vector to be coded using the target disturbance vector and the precoding matrix to obtain the signal to be sent.

[0099] Step 104: Send the signal to be sent.

[0100] Using the method provided by the embodiment of the present invention, the pre-established relational expression between the symbol vector and the disturbance vector that needs to be satisfied, and the disturbance vector satisfying the relational expression between the symbol vector to be encoded, are used as the target disturbance vector, and then After using the target perturbation vector and precoding matrix to precode the symbol vector to be coded to obtain the signal to be sent, the vector to be sent can be sent directly, that is, the energy of the sending end can be used to transmit the effective signal without the need to transmit artificial noise that is not related to the effective signal. Further, the signal sent by the sending end received by the receiving end no longer contains artificial noise, thereby improving the performance of the receiving end to receive effective signals. Moreover, by adding a target disturbance vector at the transmitting end, the equivalent noise intensity of the receiving end can be effectively reduced, thereby further improving the performance of the receiving end to receive effective signals.

[0101] The method and device provided by the present invention will be described in detail below with specific embodiments in conjunction with the accompanying drawings.

[0102] In an embodiment of the present invention, such as figure 2 As shown, the signal transmission method applied to the sending end device provided by the embodiment of the present invention may include the following steps:

[0103] Step 201: Perform quadrature amplitude modulation on the bit information stream to be transmitted to obtain a symbol vector to be coded.

[0104] Step 202: Use the following formula to determine a complex integer vector satisfying the following formula as the target complex integer vector l:

[0105]

[0106] Among them, the target complex integer vector l≠0, l'represents the complex integer vector, u represents the symbol vector to be encoded, and the disturbance vector l i With u i The directions of are not exactly the same, i represents the i-th dimension of the vector, W represents the precoding matrix, τ s = 2(c max +Δ/2)+δ τ , Τ S Indicates the ball decoding parameter, c max Represents the maximum amplitude value of the modulation constellation point, Δ represents the distance between the modulation constellation points, δ τ Indicates additional offset, δ τ Meet the range limit: ||M τ (δ τ GWl)|| 2(Δ/2) 2 , G represents the channel impulse response matrix of eavesdropping users.

[0107] Step 203: Use the following formula to multiply the target complex integer vector by the sphere decoding parameter to obtain the target disturbance vector:

[0108] p=τ s l

[0109] Among them, p represents the target disturbance vector.

[0110] In the embodiment of the present invention, an improved ball decoding algorithm can be obtained based on the standard ball decoding algorithm, and further, the target disturbance vector can be determined based on the improved ball decoding algorithm.

[0111] Step 204: Precoding the symbol vector to be coded using the target disturbance vector to obtain the signal to be transmitted.

[0112] In the embodiment of the present invention, precoding the symbol vector to be coded may specifically be:

[0113] Precoding matrix in the form of ZF (Zero-forcing precoding) is used to pre-encode the coded symbol vector; or precoding matrix in the form of RZF (Regularized Zero-forcing precoding) is used to treat The encoding symbol vector is pre-encoded.

[0114] In this step, if there are K legal user terminals in the communication system, take ZF precoding as an example. When a precoding matrix in the form of ZF precoding is used, the precoding matrix is the pseudo-inverse matrix of the channel matrix of the legal user terminal. When the symbol vector to be encoded and the target disturbance vector are superimposed, the signal to be transmitted can be expressed as:

[0115]

[0116] Where p=τ s l represents the target disturbance vector, τ s = 2(c max +Δ/2)+δ τ , Τ S Indicates the ball decoding parameter, c max Represents the maximum amplitude value of the modulation constellation point, Δ represents the distance between the modulation constellation points, δ τ Indicates additional offset, δ τ Meet the range limit: ||M τ (δ τ GWl)|| 2(Δ/2) 2 , L represents the K-dimensional target complex integer vector, W represents the precoding matrix, u represents the symbol vector to be coded, Represents the pseudo-inverse matrix of the channel matrix of the legal user terminal, β represents the power normalization constant,

[0117] Step 205: Send the signal to be sent.

[0118] In the embodiment of the present invention, the signal to be transmitted may be mapped to the corresponding antenna for transmission.

[0119] Using the method provided by the embodiment of the present invention, the pre-established relational expression between the symbol vector and the disturbance vector that needs to be satisfied, and the disturbance vector satisfying the relational expression between the symbol vector to be encoded, are used as the target disturbance vector, and then After using the target perturbation vector to pre-encode the symbol vector to be coded to obtain the signal to be transmitted, the vector to be transmitted can be directly transmitted, that is, the energy of the transmitting end can be used to transmit the effective signal without transmitting artificial noise that is not related to the effective signal; further, The signal received by the receiving end and the signal sent by the transmitting end no longer contains artificial noise, thereby improving the performance of the receiving end to receive effective signals. Moreover, by adding a target disturbance vector at the transmitting end, the equivalent noise intensity of the receiving end can be effectively reduced, thereby improving the performance of the receiving end to receive effective signals.

[0120] Based on the same inventive concept, the embodiment of the present invention also discloses a signal transmission method, which is applied to the receiving end device, such as image 3 As shown, the following steps can be included:

[0121] Step 301: Receive the signal sent by the sending end device. The signal is obtained by precoding the symbol vector to be coded by the sending end device using the target disturbance vector. The symbol vector to be coded and the target disturbance vector satisfy a pre-established relational expression, which is : The relationship between the symbol vector and the disturbance vector established based on the sphere decoding parameters and the precoding matrix.

[0122] Step 302: Using a complex modulo mode corresponding to the relational expression, perform a complex modulo operation on the received signal to obtain a signal to be demodulated.

[0123] Step 303: Demodulate the signal to be demodulated to obtain a received bit information stream.

[0124] By adopting the method provided by the embodiment of the present invention, after receiving the signal sent by the transmitting end device, by using the multiple retrieval corresponding to the relationship between the symbol vector and the disturbance vector established based on the sphere decoding parameter and the precoding matrix In the modulus mode, a complex modulo operation is performed on the received signal to obtain the signal to be demodulated. Further, the signal to be demodulated can be demodulated to obtain the received bit information stream. Since the energy of the transmitting end can be used to transmit effective signals, there is no need to transmit artificial noise that has nothing to do with the effective signal; further, the signal sent by the transmitting end received by the receiving end does not contain artificial noise, thereby improving the reception of the receiving end. Effective signal performance. In addition, the target disturbance vector added by the transmitting end can effectively reduce the equivalent noise intensity of the receiving end, thereby further improving the performance of the receiving end to receive effective signals.

[0125] In an embodiment of the present invention, such as Figure 4 As shown, the signal transmission method applied to the receiving end device provided by the embodiment of the present invention may include the following steps:

[0126] Step 401: Receive a signal sent by a sending end device.

[0127] In the embodiment of the present invention, such as Figure 5 As shown, if the point-to-point MIMO (Multiple-Input Multiple-Output) transmission model using quadrature amplitude modulation technology is used, the transmitter Alice has N A A transmitting antenna, the legal user terminal Bob has N B Root receiving antenna, eavesdropping user terminal Eve has N E A receiving antenna, where the signal vector received by Bob can be expressed as:

[0128] z=Hx+n B

[0129] The signal vector received by Eve can be expressed as:

[0130] y=Gx+n E

[0131] among them, Is a complex Gaussian noise vector whose element distribution satisfies and Represents the channel matrix at Bob, Represents the channel matrix at Eve, and x represents the signal sent by the transmitter.

[0132] Step 402: Determine the signal to be demodulated.

[0133] In the embodiment of the present invention, the target disturbance vector is calculated by using the following formula:

[0134] p=τ s l

[0135] Among them, l represents the target complex integer vector, and l≠0, p represents the target disturbance vector, τ s = 2(c max +Δ/2)+δ τ , Τ S Indicates the ball decoding parameter, c max Represents the maximum amplitude value of the modulation constellation point, Δ represents the distance between the modulation constellation points, δ τ Indicates additional offset, δ τ Meet the range limit: ||M τ (δ τ GWl)|| 2(Δ/2) 2 , G represents the channel impulse response matrix of eavesdropping users;

[0136] Among them, the target complex integer vector is calculated using the following formula:

[0137]

[0138] Among them, l'represents a vector of complex integers, u represents a vector of symbols to be encoded, and a disturbance vector l i With u i The directions of are not exactly the same, i represents the i-th dimension of the vector, and W represents the precoding matrix.

[0139] In the embodiment of the present invention, the received signal can be complex modulo, and then the obtained signal is determined as the signal to be demodulated. The specific ones can be:

[0140] For legal user terminals, the following formula can be used to modulate the received signal:

[0141]

[0142] among them, Represents the signal to be demodulated, β represents the power normalization constant, z represents the signal received by the receiving end device, Is the real part of (βz), Is the imaginary part of (βz), Λ represents the constellation area corresponding to the modulated signal, τ S Indicates the ball decoding parameter, τ indicates the standard parameter, τ=2(c max +Δ/2), and τ S Meets with τ: τ s =τ+δ τ ,δ τ Represents the additional offset, j is the imaginary unit, u represents the received bit information stream, Is a complex Gaussian noise vector whose element distribution satisfies

[0143] Among them, the constellation area corresponding to modulation can be specifically expressed as:

[0144]

[0145] Among them, c represents the constellation area corresponding to the modulation, and C represents the constellation area. From the result of the multiple modulus of the received signal by the legal user terminal, it can be known that the legitimate user terminal has eliminated the interference of the target disturbance vector in the to-be-demodulated signal obtained after performing the multiple modulus.

[0146] Step 403: Demodulate the signal to be demodulated to obtain a received bit information stream.

[0147] In the embodiment of the present invention, the legal user terminal may specifically demodulate the signal to be demodulated as follows:

[0148] Based on the relationship between the signal to be demodulated and the bit information stream, the following formula is used to demodulate the signal to be demodulated to obtain the received bit information stream:

[0149]

[0150] Among them, u represents the received bit information stream.

[0151] By adopting the method provided by the embodiment of the present invention, after receiving the signal sent by the transmitting end device, by using the multiple retrieval corresponding to the relationship between the symbol vector and the disturbance vector established based on the sphere decoding parameter and the precoding matrix In the modulo mode, a complex modulo operation is performed on the received signal to obtain the signal to be demodulated. Further, the signal to be demodulated can be demodulated to obtain the received bit information stream. Since the energy of the transmitting end can be used to transmit effective signals, there is no need to transmit artificial noise that has nothing to do with the effective signal; further, the signal sent by the transmitting end received by the receiving end does not contain artificial noise, thereby improving the reception of the receiving end. Effective signal performance. In addition, the target disturbance vector added by the transmitting end can effectively reduce the equivalent noise intensity of the receiving end, thereby improving the performance of the receiving end to receive effective signals.

[0152] In a possible implementation manner, the transmitting end can use a precoding matrix to eliminate interference between legal user terminals after passing through the channel. The commonly used precoding matrix can be among them Represents the pseudo-inverse matrix of H. In the standard vector perturbation precoding algorithm, the standard parameter τ=2(c max +Δ/2), where c max Is the maximum amplitude value of the constellation points, and Δ is the distance between the constellation points. In the embodiment of the present invention, the standard parameter τ plus an additional offset δ τ Can form the ball decoding parameter τ S : Τ s =τ+δ τ = 2(c max +Δ/2)+δ τ In the embodiment of the present invention, the disturbance vector can be obtained by using a sphere decoding algorithm.

[0153] Such as Figure 5 As shown, if the point-to-point MIMO transmission model using quadrature amplitude modulation technology is used, the transmitter Alice has N A A transmitting antenna, the legal user terminal Bob has N B Root receiving antenna, eavesdropping user terminal Eve has N E Root receiving antenna.

[0154] Such as Figure 5 As shown, the signal received by Bob can be expressed as:

[0155] z=Hx+n B

[0156] among them, Further, the signal received by Bob can be expressed as:

[0157]

[0158] Further, Bob can perform complex modulo of the received signal:

[0159]

[0160] It can be obtained that after the complex modulo operation, Bob can completely eliminate the interference introduced by the target disturbance vector p.

[0161] among them, Λ represents the constellation area corresponding to the modulated signal, which can be specifically expressed as:

[0162]

[0163] Further, Bob can demodulate the signal to be demodulated to obtain the received bit information stream:

[0164]

[0165] Such as Figure 5 As shown, the signal vector received by Eve can be expressed as:

[0166] y=Gx+n E

[0167] Among them, due to Further, the signal received by Eve can be expressed as:

[0168]

[0169] Among them, since p=τ s 1. The signal received by Eve can be further expressed as:

[0170]

[0171] It can be seen from the eavesdropping on the signal received by the user terminal that, in the embodiment of the present invention, if the worst security situation for the legitimate user terminal is considered: it can be assumed that the eavesdropping user terminal can obtain the channel matrix H and the channel matrix G, and the power normalization Constant β and modulation order, and can calculate the standard parameter τ=2(c max +Δ/2), but due to δ τ The sender agrees with the legal user terminal in advance, and the user terminal cannot get the actual used parameter τ by eavesdropping. s. Further, suppose the noise of eavesdropping on the user terminal is infinitely small, namely At this time, the signal received by the eavesdropping user terminal can be divided into two parts: the useful signal to be demodulated And interference

[0172] Further, the signal recovered by the eavesdropping user terminal using the power normalization constant β can be expressed as:

[0173]

[0174] Further, after performing the modulo operation on the recovered signal, it can be predicted that the signal obtained by eavesdropping on the user terminal is:

[0175]

[0176] Among them, M τ (r E ) Means eavesdropping on the recovered signal r E Perform multiple modulo.

[0177] In the embodiment of the present invention, consider the complex number lattice constructed by matrix GP According to the lattice theory, judge The key to whether it can be correctly demodulated into a secret signal u is to determine whether it falls in the Voronoi region (V graph area) of the target grid point GWu. Within, the security leakage probability can be defined as the probability that the eavesdropping user terminal can make a correct judgment:

[0178] In the embodiment of the present invention, to ensure that the signal is safely transmitted at the physical layer in the signal transmission system, the signal sent by the sending end meets the following two constraints:

[0179] Constraint 1: The necessary condition to ensure the safe transmission of signals at the physical layer is: l≠0.

[0180] If the vector l=0, then That is, the eavesdropping user terminal can be completely and correctly demodulated, and the safety of signal transmission cannot be guaranteed at this time. Therefore, constraint one can be obtained: the necessary condition to ensure the safe transmission of the signal at the physical layer is: l≠0.

[0181] Assuming target disturbance vector p=τ s l, all of which satisfy l≠0. At the eavesdropper, the signal obtained by eavesdropping on the user terminal is only subject to interference M τ (δ τ GWl), at the same time, such as Image 6 Shown, you can see that the interference term is Strictly aligned, which is in the plural The magnitude of the upper projection is determined by δ τ Decide with l. Such as Image 6 The projection shown on the complex number lattice of N B Meet l i For the decision area of the i-th layer of orthogonal amplitude modulation with ≠0, the constellation points can be divided into two categories according to whether the decision space is closed: the constellation point set X with closed decision space and the remaining constellation point set with half open decision space Z. For the constellation points in the set X, since the direction of the interference item is always in line with the complex number Strict alignment, when the distance between adjacent constellation points is Δ, in order to ensure that the user terminal's signal is intercepted Need to select the appropriate offset δ τ , To meet the amplitude limit in the following formula:

[0182]

[0183] For the constellation points in the set Z, because they have a half-open decision interval, only the interference term M that satisfies the amplitude limit τ (δ τ GWl) Since l i With u i May be in the same direction, the signal Voronoi may still fall on the target grid point GWu At this time, the safety of the signal transmission system cannot be guaranteed.

[0184] Based on this, constraint two can be obtained: For the constellation points in the set Z, the vector l needs to be satisfied i With u i The directions are not exactly the same. When the vector l i With u i Can only be guaranteed when the directions are not exactly the same Use mathematical notation to express the following formula:

[0185]

[0186] In the embodiment of the present invention, the safety of the signal transmission of the signal transmission system can be ensured to a greater extent through the conditions satisfied by the vector l in the constraint condition 1 and the constraint condition 2. Moreover, when the vector l completely satisfies the constraint condition one and the constraint condition two, the signal transmission security of the signal transmission system can be fully guaranteed.

[0187] In the embodiment of the present invention, an improved sphere decoding algorithm can be used to ensure that the target disturbance vector that satisfies the constraint condition 1 and constraint condition 2 is obtained, and the safety leakage probability P can be obtained. L =0. Such as Figure 7 As shown, Figure 7 Compare other solutions with the solutions provided in the embodiments of the present invention in N A =N B =N E =8, using 16-QAM modulation, the SNR (signal-to-noise ratio) at Bob is 25dB, at the offset δ τ Probability P of security leakage at the eavesdropping user terminal Eve under changes L Compared with the BER performance of the legitimate user terminal Bob. Among them, the bit error rate means: in the digital communication system, within the bit interval T, the sender sends out a binary symbol s, and after transmission, the binary symbol output by the receiver is not the probability of s.

[0188] Such as Figure 7 Shown, P L standard (standard) represents the security leakage probability of VP (Vector Perturbation precoding, vector perturbation precoding), P L Proposed (proposal) represents the security leakage probability of the solution provided by the embodiment of the present invention, Figure 7 The abscissa indicates the offset δ τ , The ordinate on the left represents the probability of security leakage, and the ordinate on the right represents the bit error rate BER at the legal user terminal Bob. Such as Figure 7 As shown, the abscissa axis is [-0.5×10 -6 , 0.5×10 -6 ], the probability of safety leakage is 1, and the equivalent transmission power of the transmitting end is the smallest. From Figure 7 It can be seen that the offset δτ satisfies When the security leakage of the VP algorithm and the solution provided by the embodiment of the present invention L =1, at the offset δ τ Satisfy VP always has a greater probability of safety leakage, and with the offset δ τ The security leakage probability of the solution provided by the embodiment of the present invention always exists P L =0. From Figure 7 As you can see in the offset δ τ =0 near the VP algorithm and the scheme provided by the embodiment of the present invention, Bob’s bit error rate is the lowest, and the performance of the signal transmission system is the best; τ <0, because the receiving end will introduce a large number of constellation point overlaps after re-modulation, resulting in BER increasing with δ τ The decrease in the transmission rate increases exponentially, so it is usually selected when designing a secure transmission scheme

[0189] Such as Figure 8 As shown, Figure 8 Shows that the number of antennas is N A = 6, N B =N E = 4, and the offset δ τ When =0.51Δ, the signal transmission system performance of the solution provided by the embodiment of the present invention is compared with the classical VP algorithm and the two artificial noise solutions.

[0190] Figure 8 Where proposedVP represents the solution provided by the embodiment of the present invention, standardVP represents the solution based on the standard VP algorithm, and AN-ZF and ANVP represent two other artificial noise solutions that are different from the embodiment of the present invention. Figure 8 Among them, the abscissa represents the signal-to-noise ratio at the legal user terminal Bob, and the ordinate on the left represents the security leakage probability P L , The ordinate on the right represents the bit error rate BER at the legal user terminal Bob.

[0191] Figure 8 The solid line is the safety performance comparison of different schemes. It can be seen that the standard VP algorithm has the largest safety leakage probability, which is about 3×10- on average. 1 Around, the security leakage probability of the AN-ZF solution averages about 10- 4 The probability of security leakage based on the ANVP scheme is about 10- 5 However, the security leakage probability of the solution provided by the embodiment of the present invention is zero. From Figure 8 We can also see that the standard VP algorithm can achieve the lowest bit error rate, that is, the optimal diversity gain. The solution provided by the embodiment of the invention takes into account system security, compared to the AN-ZF and ANVP artificial noise solutions. It has a lower bit error rate, that is, the performance of the signal transmission system is better.

[0192] In the embodiment of the present invention, the target disturbance vector can be determined based on the improved ball decoding algorithm in the following manner:

[0193] Step A1: Convert the symbol vector to be encoded into an equivalent real number vector

[0194] Step A2, determine the real number form of the target vector of the ball decoding algorithm Where u t Represents the target vector of the ball decoding algorithm;

[0195] Step A3, calculate τ s And the linear real matrix corresponding to W;

[0196] In this step, the corresponding linear real matrix can be expressed as:

[0197]

[0198] Where H t Represents the corresponding linear real matrix;

[0199] Step A4, calculate matrix H t Corresponding QR decomposition and diagonal matrix.

[0200] Among them, QR decomposition can be expressed as:

[0201] [Q t , R t ]=QR(H t )

[0202] The diagonal matrix can be expressed as:

[0203] D=diag(sign(diag(R t )));

[0204] Step A5: Based on the target vector, QR decomposition and diagonal matrix of the sphere decoding algorithm, calculate the disturbance vector that satisfies the constraint condition 1 and the preset constraint condition 2 and has the minimum distance as the target disturbance vector.

[0205] In the artificial noise scheme, in order to achieve the effect that the artificial noise vector only causes interference to the eavesdropping user terminal, the selection of the noise vector must be carried out in the null space of the legal user terminal channel, so the channel of the legal user terminal must have a non-zero zero Space, that is, the number of legal user terminal antennas must be less than the number of antennas at the transmitting end. However, in the embodiment of the present invention, there is no need to meet the limit on the number of antennas, that is, the number of antennas of the legal user terminal may not be less than the number of antennas at the transmitting end, which increases the spatial freedom of signal transmission compared with the prior art, and the solution provided by the embodiment of the present invention Only need to meet the unknown offset δ of the eavesdropping user terminal τ In this case, the security of signal transmission can be ensured, and the security leakage of the transmission signal caused by artificial noise schemes in a scenario with a small number of antennas and a low modulation order is avoided.

[0206] Based on the same inventive concept, according to the signal transmission method provided by the above-mentioned embodiment of the present invention, correspondingly, another embodiment of the present invention also provides a signal transmission device, which is applied to the transmitting end device, and its structure diagram is as Picture 9 As shown, specifically including:

[0207] The modulation module 901 is configured to perform quadrature amplitude modulation on the bit information stream to be transmitted to obtain a symbol vector to be coded;

[0208] The determining module 902 is configured to determine the disturbance vector satisfying the relationship with the symbol vector to be coded based on the relationship that needs to be satisfied between the pre-established symbol vector and the disturbance vector, as the target disturbance vector, the relationship is: based on ball translation The relationship between the symbol vector established by the code parameter and the precoding matrix and the disturbance vector;

[0209] The precoding module 903 is configured to precode the symbol vector to be coded using the target disturbance vector and the precoding matrix to obtain the signal to be sent;

[0210] The signal sending module 904 is used to send the signal to be sent.

[0211] It can be seen that using the device provided in the embodiment of the present invention, the pre-established relationship between the symbol vector and the perturbation vector and the perturbation vector satisfying the relationship with the symbol vector to be encoded are used as the target perturbation vector , And then after using the target disturbance vector to pre-code the symbol vector to be coded to obtain the signal to be sent, the vector to be sent can be directly sent, that is, the energy of the sending end can be used to transmit the effective signal without the need to transmit artificial noise that is not related to the effective signal; further Yes, the signal received by the receiving end from the transmitting end no longer contains artificial noise, thereby improving the performance of the receiving end to receive effective signals. Moreover, by adding the target disturbance vector at the transmitting end, the equivalent noise intensity of the receiving end can be effectively reduced, thereby further improving the performance of the receiving end to receive effective signals.

[0212] Further, the determining module 902 is specifically configured to use the following formula to determine a complex integer vector satisfying the following formula as the target complex integer vector l:

[0213]

[0214] The determining module 902 is specifically further configured to use the following formula to multiply the target complex integer vector by the sphere decoding parameter to obtain the target disturbance vector:

[0215] p=τ s l

[0216] Among them, the target complex integer vector l≠0, p represents the target perturbation vector, l'represents the complex integer vector, u represents the symbol vector to be encoded, and the perturbation vector l i With u i The directions of are not exactly the same, i represents the i-th dimension of the vector, W represents the precoding matrix, τ s = 2(c max +Δ/2)+δ τ , Τ S Indicates the ball decoding parameter, c max Represents the maximum amplitude value of the modulation constellation point, Δ represents the distance between the modulation constellation points, δ τ Indicates additional offset, δ τ Meet the range limit: ||M τ (δ τ GWl)|| 2(Δ/2) 2 , G represents the channel impulse response matrix of eavesdropping users.

[0217] Further, the precoding module 1003 is specifically configured to use the following formula to precode the symbol vector to be coded by using the target disturbance vector and the precoding matrix to obtain the signal to be sent:

[0218]

[0219] Among them, β represents the power normalization constant, x represents the signal to be sent.

[0220] Another embodiment of the present invention also provides a signal transmission device, which is applied to the receiving end equipment, and its structure diagram is as Picture 10 As shown, specifically including:

[0221] The signal receiving module 1001 is used to receive the signal sent by the sending end device. The signal is obtained by the sending end device using the target disturbance vector and precoding matrix to pre-encode the symbol vector to be coded. The established relational expression is: the relational expression between the symbol vector and the disturbance vector established based on the sphere decoding parameters and the precoding matrix;

[0222] The complex modulus module 1002 is configured to adopt a complex modulus method corresponding to the relational expression to perform a complex modulus operation on the received signal to obtain a signal to be demodulated;

[0223] The demodulation module 1003 is used to demodulate the signal to be demodulated to obtain the received bit information stream.

[0224] It can be seen that using the device provided by the embodiment of the present invention, after receiving the signal sent by the transmitting end device, it adopts the formula corresponding to the relationship between the symbol vector and the disturbance vector established based on the sphere decoding parameter and the precoding matrix. The multiple modulus mode is to perform multiple modulus operations on the received signal to obtain the signal to be demodulated. Further, the signal to be demodulated can be demodulated to obtain the received bit information stream. Since the energy of the transmitting end can be used to transmit effective signals, there is no need to transmit artificial noise that has nothing to do with the effective signal; further, the signal sent by the transmitting end received by the receiving end does not contain artificial noise, thereby improving the reception of the receiving end. Effective signal performance. Moreover, by adding the target disturbance vector at the transmitting end, the equivalent noise intensity of the receiving end can be effectively reduced, thereby further improving the performance of the receiving end to receive effective signals.

[0225] Further, the target disturbance vector is calculated using the following formula:

[0226] p=τ s l

[0227] Among them, l represents the target complex integer vector, and l≠0, p represents the target disturbance vector, τ s = 2(c max +Δ/2)+δ τ , Τ S Indicates the ball decoding parameter, c max Represents the maximum amplitude value of the modulation constellation point, Δ represents the distance between the modulation constellation points, δ τ Indicates additional offset, δ τ Meet the range limit: ||M τ (δ τ GWl)|| 2(Δ/2) 2 , G represents the channel impulse response matrix of eavesdropping users;

[0228] The target complex integer vector is calculated using the following formula:

[0229]

[0230] Among them, l'represents a vector of complex integers, u represents a vector of symbols to be encoded, and a disturbance vector l i With u i The directions of are not completely the same, i represents the i-th dimension of the vector, and W represents the precoding matrix;

[0231] The complex modulus module 1002 is specifically used to determine the signal to be demodulated by using the following formula:

[0232]

[0233] among them, Represents the signal to be demodulated, β represents the power normalization constant, z represents the signal received by the receiving device, Is the real part of (βz), Is the imaginary part of (βz), Λ represents the constellation area corresponding to the modulated signal, τ S Represents the ball decoding parameter, τ represents the standard parameter, and τ S Meets with τ: τ s =τ+δ τ ,δ τ Represents the extra offset, j is the imaginary unit.

[0234] Further, the demodulation module 1003 is specifically configured to use the following formula to demodulate the signal to be demodulated based on the relationship between the signal to be demodulated and the bit information stream to obtain the received bit information stream:

[0235]

[0236] Among them, u represents the received bit information stream, Is a complex Gaussian noise vector whose element distribution satisfies

[0237] Based on the same inventive concept, according to the risk identification method provided by the above-mentioned embodiment of the present invention, correspondingly, another embodiment of the present invention also provides an electronic device, see Picture 11 The electronic device in the embodiment of the present invention includes a processor 1101, a communication interface 1102, a memory 1103, and a communication bus 1104. The processor 1101, the communication interface 1102, and the memory 1103 communicate with each other through the communication bus 1104.

[0238] The memory 1103 is used to store computer programs;

[0239] The processor 1101 is configured to execute the program stored in the memory 1103 and implement the following steps:

[0240] Perform quadrature amplitude modulation on the bit information stream to be transmitted to obtain the symbol vector to be coded;

[0241] Based on the pre-established relationship between the symbol vector and the disturbance vector, the disturbance vector that satisfies the relationship with the symbol vector to be encoded is determined as the target disturbance vector, and the relationship is: based on ball translation The relationship between the symbol vector established by the code parameter and the precoding matrix and the disturbance vector;

[0242] Precoding the symbol vector to be coded using the target disturbance vector to obtain the signal to be transmitted;

[0243] Sending the signal to be sent.

[0244] Based on the same inventive concept, according to the risk identification method provided by the above-mentioned embodiment of the present invention, correspondingly, another embodiment of the present invention also provides an electronic device, see Picture 12 The electronic device of the embodiment of the present invention includes a processor 1201, a communication interface 1202, a memory 1203, and a communication bus 1204. The processor 1201, the communication interface 1202, and the memory 1203 communicate with each other through the communication bus 1204.

[0245] The memory 1203 is used to store computer programs;

[0246] The processor 1201 is configured to execute the program stored in the memory 1203 to implement the following steps:

[0247] Receive a signal sent by a sending end device, where the signal is obtained by precoding a symbol vector to be coded by the sending end device using a target disturbance vector, and the symbol vector to be coded and the target disturbance vector satisfy a pre-established relationship Formula, the relationship is: the relationship between the symbol vector and the disturbance vector established based on the sphere decoding parameter and the precoding matrix;

[0248] Adopting the complex modulus mode corresponding to the relational expression to perform complex modulo operation on the received signal to obtain the signal to be demodulated;

[0249] Demodulate the signal to be demodulated to obtain a received bit information stream.

[0250] The communication bus mentioned in the above electronic device may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus. The communication bus can be divided into address bus, data bus, control bus and so on. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0251] The communication interface is used for communication between the aforementioned electronic device and other devices.

[0252] The memory may include random access memory (Random Access Memory, RAM), and may also include non-volatile memory (Non-Volatile Memory, NVM), such as at least one disk memory. Optionally, the memory may also be at least one storage device located far away from the foregoing processor.

[0253] The foregoing processor may be a general-purpose processor, including a central processing unit (Central Processing Unit, CPU), a network processor (Network Processor, NP), etc.; it may also be a digital signal processor (Digital Signal Processing, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), Field-Programmable Gate Array (FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components.

[0254] In yet another embodiment provided by the present invention, a computer-readable storage medium is also provided. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the application to the sending-end device is realized. Of any method of signal transmission.

[0255] In another embodiment provided by the present invention, there is also provided a computer program product containing instructions, which when run on a computer, causes the computer to execute any of the above-mentioned signal transmission methods applied to the sending end device.

[0256] In yet another embodiment provided by the present invention, a computer-readable storage medium is also provided. The computer-readable storage medium stores a computer program. When the computer program is executed by a processor, the application to the receiving end device is realized. Of any method of signal transmission.

[0257] In another embodiment provided by the present invention, there is also provided a computer program product containing instructions, which when running on a computer, causes the computer to execute any of the above-mentioned signal transmission methods applied to the receiving end device.

[0258] In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in the form of a computer program product in whole or in part. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on the computer, the processes or functions described in the embodiments of the present invention are generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center. Transmission to another website site, computer, server or data center via wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server or a data center integrated with one or more available media. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, and a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid state disk (SSD)).

[0259] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply one of these entities or operations. There is any such actual relationship or order between. Moreover, the terms "include", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also includes Other elements of, or also include elements inherent to this process, method, article or equipment. If there are no more restrictions, the element defined by the sentence "including a..." does not exclude the existence of other same elements in the process, method, article, or equipment including the element.

[0260] Each embodiment in this specification is described in a related manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the difference from other embodiments. In particular, for the device, electronic equipment, and storage medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and for related parts, please refer to the part of the description of the method embodiments.

[0261] The foregoing descriptions are only preferred embodiments of the present invention, and are not used to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are all included in the protection scope of the present invention.

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## Description & Claims & Application Information

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