A secure communication method for eavesdropping on NOMA networks based on artificial noise
By combining and interfering with signals at relay nodes, and by integrating relay selection, artificial noise, and one-time pad techniques, the problem of eavesdropping attacks on relay cooperative NOMA networks is solved, thereby improving the physical layer security and reliability of the network.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-12
- Publication Date
- 2026-03-10
AI Technical Summary
While providing wider coverage and services to more users, relay-cooperative NOMA networks face security challenges from external eavesdropping attacks, and existing technologies are insufficient to effectively enhance physical layer security.
By combining relay selection, artificial noise, and one-time password technology, a physical layer secure communication scheme is designed. By combining and interfering with signals at relay nodes, the attack capability of eavesdropping users is weakened.
It significantly improves the physical layer security of cooperative NOMA networks, reduces the opportunity for eavesdropping users to directly obtain legitimate user information, and enhances the security-reliability balance performance of the system.
Smart Images
Figure CN120075792B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a physical layer secure communication scheme for resisting eavesdropping attacks in cooperative non-orthogonal multiple access (NOMA) networks, belonging to the field of wireless communication physical layer security technology, and particularly to combining artificial noise technology and traditional one-time pad technology to resist external eavesdropping attacks on relay cooperative NOMA networks. Background Technology
[0002] Advances in network and wireless communication technologies have enabled a wide variety of terminal devices to connect to networks. The emergence and rise of the Internet of Things (IoT) have further accelerated this trend, leading to an explosive growth in network data transmission and making spectrum resources even scarcer. Cooperative relay technology can expand signal coverage, allowing more users to connect to the communication network and improving data transmission efficiency. No-Multiple-User Aspects (NOMA) technology can serve multiple users simultaneously, alleviating the current spectrum shortage. Therefore, the combination of relay cooperation technology and NOMA technology can allow the network to provide better services to more users. However, while providing services to more users, relay cooperation NOMA networks also allow more users to connect to the network, giving more users the opportunity to obtain legitimate user information, which poses greater challenges to current network communication security. Currently, traditional cryptographic techniques rely on mathematically difficult problems to build secure communication schemes. Summary of the Invention
[0003] Purpose of the Invention: The purpose of this invention is to provide a secure communication method for NOMA networks used for eavesdropping based on artificial noise. In situations where a relay-cooperative NOMA network is attacked by external eavesdropping users, this invention proposes a physical layer secure communication scheme. The secure communication scheme designed in this invention, based on relay selection, artificial noise, and one-time pad technology, can efficiently achieve secure communication between near and far users. Moreover, the security-reliability balance performance of this invention's secure communication scheme has a significant advantage over existing secure communication schemes.
[0004] Technical Solution: This invention provides a secure communication method for eavesdropping on NOMA networks based on artificial noise. This method is applied to communication scenarios where a cooperative non-orthogonal multiple access (NOMA) network with multiple relay nodes is subjected to eavesdropping attacks. The system includes a source user, several relay nodes equipped with two antennas, a single-antenna near-user, a single-antenna far-user, and a single-antenna eavesdropping user. The secure communication method includes the following steps:
[0005] Step 1: In the first time slot, the source uses NOMA technology to linearly combine the near user message x1 and the far user message x2 to obtain a mixed signal. Where α1 and α2 represent the power allocation coefficients of x1 and x2, respectively, α2 > α1 > 0 and α1 + α2 = 1; then, the source sends the NOMA signal to the relay node selected based on the maximum-minimum relay selection scheme. This relay node uses full-duplex technology, where one antenna receives the NOMA signal while the other antenna transmits the artificial noise signal x. J Interference with user E; relay nodes, near users, far users, and eavesdropping users calculate the corresponding signal-to-noise ratio and signal-to-interference-plus-noise ratio based on the received signals;
[0006] Step 2: In the second time slot, the selected relay node decodes signals x1 and x2, and then... J Looking at the bit string, connect x1 and x2 with x respectively. J XOR addition yields the signal. and The NOMA signal is obtained again using the NOMA technique. The selected relay node transmits signal x r The signal source acts as an interference node, simultaneously emitting artificial noise signal x. J1 To mitigate eavesdropping attacks; finally, the near user, the far user, and the eavesdropping user calculate the signal-to-interference-plus-noise ratio and signal-to-noise ratio of the relevant signals based on their respective received signals; considering the worst case, the eavesdropping user is assumed to be a strong eavesdropper, thus the eavesdropping user ignores the serial interference between NOMA signals;
[0007] Step 3: Near-user, far-user, and eavesdropping user calculate the corresponding interruption probability and eavesdropping probability based on the obtained signal-to-interference-plus-noise ratio and signal-to-noise ratio.
[0008] Furthermore, in step 1, the relay node R selected in the first time slot i Based on the received signal x, the signal-to-interference-plus-noise ratios (SIRs) of the decoded signals x2 and x1 can be calculated as follows:
[0009]
[0010] Among them, P s1 The source signal transmission power, relay node R i The power of the additive white Gaussian noise at the location is h si This represents the instantaneous channel state information from the source to the selected relay node, where I is the residual self-interference signal-to-noise ratio of the selected relay node. If the eavesdropping user is strongly eavesdropping, then the signal-to-interference-to-noise ratio of the eavesdropping user with respect to signals x2 and x1 is:
[0011]
[0012] Among them, h se and h ie P represents the instantaneous channel state information from the source and the selected relay node to the eavesdropping user, respectively.r1 The signal transmission power of the selected relay node is [value], and the additive white Gaussian noise power at the eavesdropping user is [value]. Because the relay node uses XOR operation, the two NOMA users and the eavesdropping user need to decode the artificial noise signal x. J Thus, the signal x is relevant to both near and far users. J The signal-to-noise ratio and the decoded signal of the eavesdropping user x J The signal-to-interference-plus-noise ratios are as follows:
[0013]
[0014] in, and P represents the instantaneous channel state information from the selected relay node to the near user and the far user, respectively. r1 The power of the artificial noise signal transmitted by the selected relay node in the first time slot. and These represent the Gaussian white noise power at the near user and the far user locations, respectively.
[0015] Furthermore, in step 1, the signal-to-interference-plus-noise ratio (SIR) of the relay nodes selected in the first time slot decoding signals x1 and x2, and the artificial noise signal x decoded by NOMA users and eavesdropping users are further analyzed. J The signal-to-interference-plus-noise ratio (SIR) or SIR calculation process is as follows: First, from the relay node set... Select a relay node from the list. The relay selection rules are as follows:
[0016]
[0017] While receiving the NOMA signal from the source, the relay node also needs to send an artificial noise signal x. J When interfering with eavesdropping users, the signal received by the relay node is:
[0018]
[0019] Where, n i h represents the additive white Gaussian noise at the relay node. ii The residual self-interference after signal cancellation at the relay node; the relay node calculates the signal-to-interference-to-noise ratios (SNRs) of signals x1 and x2 based on the received signals. and The received signals for near users, far users, and eavesdropping users are as follows:
[0020]
[0021] in, and n eLet $\mathbf{R}$ represent the additive white Gaussian noise at the near user, far user, and eavesdropping user, respectively. Based on the received signals, the signal-to-noise ratio (SNR) and signal-to-interference-plus-noise ratio (SINNR) of the near user, far user, and eavesdropping user are calculated as follows: and
[0022] Furthermore, in step 2, the second time slot near the user decoding signal and The signal-to-interference-plus-noise ratio (SINR) and signal-to-noise ratio (SNR) are respectively:
[0023]
[0024] Among them, P r2 Indicates the transmit power of the second time slot signal of the selected relay node; remote user decoded signal The signal-to-interference-plus-noise ratio is:
[0025]
[0026] Based on the eavesdropping user's strong eavesdropping ability, information about the signal can be obtained from the eavesdropping user. and The signal-to-interference-plus-noise ratio is:
[0027]
[0028] Among them, P s2 This indicates the power of the artificial noise transmitted by the source user in the second time slot.
[0029] Furthermore, in step 2, in the second time slot, the process of calculating the signal-to-interference-plus-noise ratio (SINR) and signal-to-noise ratio (SNR) of the relevant signals is as follows: the relay node combines the decoded signals x1 and x2 with the artificial noise signal x sent in the first time slot. J XOR addition, followed by NOMA technique, yields a mixed signal. The signal is then sent to the NOMA user, while the source simultaneously sends artificial noise x. J1 Weakening the eavesdropping user; thus, the received signals of the near user, the far user, and the eavesdropping user are respectively:
[0030]
[0031]
[0032] Combining NOMA mechanism, near-user decoding and The signal-to-interference-plus-noise ratios are respectively and Remote user decoding The signal-to-interference-plus-noise ratio is The eavesdropping user has strong eavesdropping capabilities; their decoded signals... and The signal-to-interference-plus-noise ratios are respectively and
[0033] Furthermore, in step 3, the interruption probability calculation process is as follows: According to the NOMA mechanism and relay cooperation strategy, after the first time slot data transmission ends, the selected relay node needs to decode signals x2 and x1, as long as... and Recently, a user successfully decoded x. J The conditions are In the second time slot, according to the NOMA mechanism, as long as Users can successfully decode Based on this analysis, the probability of interruption near the user is:
[0034]
[0035] For a remote user to decode x2, the relay node needs to successfully decode x2 and x1 in the first time slot, and the remote user also needs to decode the artificial noise signal x in the first time slot. J Second time slot signal Therefore, the remote user interruption probability is:
[0036]
[0037] Furthermore, in step 3, the eavesdropping probability calculation process is as follows: There are two scenarios where signal x1 is eavesdropped on: one is that the eavesdropper directly intercepts the source message x1; the other is that the eavesdropping user cannot directly obtain x1, and the user needs to decode x1. J and Then, using the properties of the XOR operation, we obtain x1. Therefore, the probability that the user near us is being eavesdropped on is:
[0038]
[0039] The probability that a remote user is being eavesdropped on is:
[0040]
[0041] The present invention also discloses a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method of the present invention.
[0042] The present invention also discloses a computer-readable storage medium having a computer program / instructions stored thereon, which, when executed by a processor, implements the steps of the method of the present invention.
[0043] The present invention also discloses a computer program product, including a computer program / instructions that, when executed by a processor, implement the steps of the method of the present invention.
[0044] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages:
[0045] 1. This invention combines cooperative relay and NOMA technology, which can expand the coverage of wireless signals and increase the utilization of spectrum resources, thus providing services to more users;
[0046] 2. This invention combines relay selection strategy, artificial noise technology and one-time pad encryption technology to construct a secure communication scheme. Compared with traditional secure communication schemes, the eavesdropping user of this invention has only one chance to directly intercept the source message, while the eavesdropping user of existing secure communication schemes has two chances to directly obtain the source message. Thus, the secure communication scheme proposed in this invention can effectively enhance the physical layer security of the system.
[0047] 3. Unlike traditional cryptographic techniques, physical layer security only requires utilizing the randomness of wireless channels or signals to achieve perfectly confidential data transmission. This invention combines artificial noise technology and relay cooperation strategies from physical layer security techniques with one-time pad technology to construct a secure communication scheme for cooperative NOMA networks. Existing physical layer secure communication schemes applied to cooperative NOMA networks give eavesdropping users two opportunities to directly obtain legitimate user information. In contrast, the scheme of this invention gives eavesdropping users only one opportunity to directly intercept legitimate user information, thereby effectively enhancing the physical layer security of cooperative NOMA networks subjected to eavesdropping attacks. Attached Figure Description
[0048] Figure 1 This is a system model diagram of a secure communication scheme for eavesdropping on NOMA networks based on artificial noise, according to the present invention.
[0049] Figure 2 This is a flowchart of a secure communication scheme for eavesdropping on NOMA networks based on artificial noise, according to the present invention.
[0050] Figure 3 This is a comparison chart of the safety-reliability balance performance of the present invention and the comparative scheme for two NOMA users. Detailed Implementation
[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to system model diagrams, flowcharts, and experimental simulation results.
[0052] like Figure 1As shown, the relay cooperative NOMA communication system model includes one source user, three relay nodes with two antennas each, one near-user with a single antenna, one far-user with a single antenna, and one eavesdropping user with a single antenna.
[0053] The process of this invention is as follows Figure 2 As shown,
[0054] Step 1: The source user uses the NOMA mechanism to construct the signal. The signal x is then sent to the relay node selected according to the maximum and minimum relay selection scheme. The selected relay node operates in full-duplex mode, receiving the signal while simultaneously transmitting artificial noise signal x. J Interfering with or eavesdropping on users;
[0055] Step 2: The selected relay node receives the signal as follows: Therefore, the signal-to-interference-plus-noise ratio can be calculated. and The received signals for near users, far users, and eavesdropping users are respectively and Therefore, the signal-to-noise ratio (SNR) and signal-to-interference-plus-noise ratio (SINNR) of the signals corresponding to the near user, far user, and eavesdropping user can be calculated as follows: and
[0056] Step 3: If the selected relay node can decode signals x1 and x2, then transmit x1, x2, and x... J Viewed as a bit sequence, we can obtain and Next, the NOMA mechanism is used to obtain the mixed signal. Finally, x r Send to NOMA user; if the selected relay node cannot correctly decode source signals x1 and x2, proceed to step 5;
[0057] Step 4: The signals received by the near user, the far user, and the eavesdropping user are respectively and The corresponding signal-to-noise ratios for near users, far users, and eavesdropping users can be calculated as follows: and
[0058] Step 5: The interruption probabilities for near and far users are calculated based on the obtained signal-to-interference-plus-noise ratio (SIR) and signal-to-noise ratio (SNR), respectively:
[0059]
[0060] and
[0061]
[0062] The probabilities of being eavesdropped on for nearby users and distant users are as follows:
[0063]
[0064] and
[0065]
[0066] The following is a Matlab numerical simulation experiment to realize the interruption probability of near and far users, as well as the eavesdropping probability of them. In the simulation experiment, after the user distance is normalized, the coordinates of the source user are (-1,0)(-1,0), the coordinates of the near user and the far user are (1,0) and (1,1) respectively, and the position of the eavesdropping user is (0,-1). The relay nodes are distributed on a circle with a center of (0,0) and a radius of 0.05. Relay node R i The coordinates are Where N = 3, i = 1, 2, 3. In this cooperative NOMA network, all channels are Rayleigh fading. The additive Gaussian noise power of each user in the network is equal, and is σ. 2 The power of the signals transmitted by each node in the system is P, resulting in a transmission signal-to-noise ratio of P. The residual self-interference signal-to-noise ratio is a constant I = 1, the power allocation coefficients are α1 = 0.1, α2 = 0.9, and the correlation thresholds are γ1 = 7, γ2 = 3, γ e =2. The following uses the Security-Reliability Tradeoff (SRT) to characterize the security of NOMA users.
[0067] Figure 3 This is a comparison chart of the reliability-balanced performance curves of the present invention, the non-artificial noise secure communication scheme, and the traditional artificial noise secure communication scheme applied to a cooperative NOMA network under eavesdropping attacks. Figure 3 As can be seen, the security-reliability balance performance of the present invention for both near and far users is significantly better than that of the non-artificial noise secure communication scheme and the traditional artificial noise secure communication scheme for the corresponding users.
Claims
1. A secure communication method for eavesdropping on NOMA networks based on artificial noise, applied to a communication scenario where a cooperative non-orthogonal multiple access (NOMA) network with multiple relay nodes is subjected to eavesdropping attacks, characterized in that... The system comprises a source user, several relay nodes with two antennas, a near user with a single antenna, a far user with a single antenna and an eavesdropping user with a single antenna, and the secure communication method comprises the following steps: Step 1, in the first time slot, the source uses NOMA technology to linearly combine the near user message and the far user message to obtain a mixed signal , wherein and respectively represent the power allocation coefficients of and , , ; then, the source sends the NOMA signal to the relay node selected based on the maximum minimum relay selection scheme, and the relay node uses full duplex technology, that is, one antenna receives the NOMA signal and the other antenna sends an artificial noise signal to interfere with the eavesdropping user ; the relay node, the near user, the far user and the eavesdropping user calculate the corresponding signal-to-noise ratio and signal-to-interference ratio according to the received signal; In step 1, the first time slot selected relay node According to the received signal , the signal-to-noise ratio of the decoded signal and is respectively ； ； wherein, is the source signal transmit power, the relay node is the additive white Gaussian noise power at the relay node , represents the instantaneous channel state information from the source to the selected relay node, is the residual self-interference signal-to-noise ratio of the selected relay node; the eavesdropping user is strongly eavesdropping, then the eavesdropping user's signal-to-noise ratio with respect to the signal and is: ； wherein, and respectively denote the instantaneous channel state information of the source and the selected relay node to the eavesdropping user, is the signal transmit power of the selected relay node, and the additive white Gaussian noise power at the eavesdropping user is ; because the relay node adopts the XOR operation, the two NOMA users and the eavesdropping user need to decode the artificial noise signal , so that the near user, the far user and the eavesdropping user decode the signal , the signal-to-noise ratio of the near user, the far user and the eavesdropping user decoding the signal is respectively: ； ； ； wherein, and H1and H2denote the instantaneous channel state information of the selected relay node to the near user and the far user, respectively, P1is the power of the artificial noise signal transmitted by the selected relay node in the first time slot, and and Step 2: In the second time slot, the selected relay node decodes the signal. and ,Bundle , and Looking at the bit string, and respectively with XOR addition yields the signal. and The NOMA signal is obtained again using the NOMA technique. The selected relay node transmits signals. The signal source acts as an interference node, simultaneously emitting artificial noise signals. To mitigate eavesdropping attacks; finally, the near user, the far user, and the eavesdropping user calculate the signal-to-interference-plus-noise ratio and signal-to-noise ratio of the relevant signals based on their respective received signals; considering the worst case, the eavesdropping user is assumed to be a strong eavesdropper, thus the eavesdropping user ignores the serial interference between NOMA signals; Step 2, second time slot near user decodes signal and The signal to interference and noise ratio and the signal to noise ratio for the second time slot near user are respectively: ； ； wherein represents the selected relay node second time slot signal transmit power; the far user decodes the signal with a signal to interference and noise ratio of: ； Based on the strong eavesdropping ability of the eavesdropping user, the signal-to-interference-and-noise ratio of the eavesdropping user with respect to the signal and may be obtained as: ； wherein, P2 represents the power at which the second time slot source users transmit artificial noise; Step 3, the near user, the far user and the eavesdropping user calculate the corresponding outage probability and eavesdropping probability according to the obtained signal-to-interference-and-noise ratio and signal-to-noise ratio.
2. The secure communication method for a passive eavesdropping NOMA network based on artificial noise according to claim 1, characterized in that, In step 1, the selected relay node in the first time slot decodes the signal and The signal-to-interference-plus-noise ratio of the NOMA users and the eavesdropping users decoding the artificial noise signal The signal-to-interference-plus-noise ratio or signal-to-noise ratio calculation process is as follows: first, a relay node is selected from the relay node set The relay selection rule here is that ； The relay node receives the NOMA signal from the source and transmits an artificial noise signal The relay node receives the NOMA signal from the source and transmits an artificial noise signal ； wherein, denotes the additive white Gaussian noise at the relay node, is the residual self-interference after self-interference signal cancellation at the relay node; the relay node calculates the signal and from the received signal and ; the received signals of the near user, the far user and the eavesdropping user are respectively ； ； ； wherein, , and represent the additive white Gaussian noise at the near user, the far user and the eavesdropping user, respectively; the near user, the far user and the eavesdropping user calculate the signal-to-noise ratio and the signal-to-interference noise ratio of the corresponding signal based on the received signal, respectively as , and .
3. The method of claim 1, wherein, In step 2, during the second time slot, the process of calculating the signal-to-interference-plus-noise ratio (SINR) and signal-to-noise ratio (SNR) of the relevant signals is as follows: the relay node decodes the obtained signal... and Artificial noise signal transmitted in its first time slot XOR addition, followed by NOMA technique, yields a mixed signal. The signal is then sent to NOMA users, while the source simultaneously transmits artificial noise. Weakening the eavesdropping user; thus, the received signals of the near user, the far user, and the eavesdropping user are respectively: ； ； ； Combining NOMA mechanism, near user decodes and with signal-to-interference-and-noise ratio and , far user decodes with signal-to-interference-and-noise ratio ; the eavesdropping user has strong eavesdropping ability, and decodes signals and with signal-to-interference-and-noise ratio and .
4. The secure communication method for a passive eavesdropping NOMA network based on artificial noise according to claim 1, characterized in that, In step 3, the outage probability calculation process is as follows: according to the NOMA mechanism and the relay cooperation strategy, the first time slot data transmission ends, and the selected relay node decodes the signal and , as long as and , the near user successfully decodes , the condition is ; The second time slot, according to the NOMA mechanism, only if and , the near user can successfully decode ; based on this analysis, the near user outage probability is: ； The far user needs to decode the first time slot successfully and the far user also needs to decode the artificial noise signal in the first time slot and the signal in the second time slot Therefore, the outage probability of the far user is 。 5. The secure communication method for eavesdropping NOMA network based on artificial noise of claim 1, wherein, In step 3, the eavesdropping probability calculation process is as follows: signal There are two cases of eavesdropping, one is that the eavesdropper directly obtains the source message ; the other is that the eavesdropping user cannot directly obtain , the near user needs to decode and , and then obtains Therefore, the probability of eavesdropping of the near user is: ； The probability of the far user suffering from eavesdropping is: 。 6. A computer apparatus comprising a memory, a processor, and a computer program stored on the memory, wherein the computer program, when executed by the processor, causes the processor to perform the method of any one of claims 1 to 5. The processor executes the computer program to realize the steps of the method in claim 1.
7. A computer readable storage medium having stored thereon a computer program or instructions, characterized in that, The computer program or instruction is executed by the processor to realize the steps of the method in claim 1.
8. A computer program product comprising computer programs or instructions, characterized in that, The computer program or instruction is executed by the processor to realize the steps of the method in claim 1. The computer program or instruction is executed by the processor to realize the steps of the method in claim 1.