STAR-RIS assisted CR-NOMA network and interruption performance analysis method thereof

Abstract

The invention belongs to the technical field of wireless communication, and particularly relates to an STAR-RIS assisted CR-NOMA network and an interruption performance analysis method thereof. The method for analyzing the interruption performance of the STAR-RIS assisted CR-NOMA network comprises the following steps: constructing a novel passive STAR-RIS assisted coverage CR-NOMA network communication model, solving a signal to interference plus noise ratio of a received signal, deducing an analytical expression of an interruption probability, determining an asymptotic expression of a high signal to noise ratio region, and analyzing the diversity and order of a user. And the STAR-RIS, the RSMA and the cognitive radio are innovatively combined, so that the spectrum efficiency is enhanced, and the practicability of guiding the deployment of the wireless network system is improved. The disruption performance analysis method of the STAR-RIS assisted CR-NOMA network is used for guiding the deployment of a wireless network system, the problems of small coverage range, low deployment flexibility, high cost and power consumption and the like of the wireless network can be solved, the spectrum utilization rate is improved, the coverage range is expanded, and the disruption probability, the energy consumption and the operation cost of the wireless network system are reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless communications, and in particular relates to a STAR-RIS assisted CR-NOMA network and an interruption performance analysis method thereof. Background Art

[0002] As the superconnector between the physical and digital worlds, the Internet of Things (IoT) connects sensors, devices, and networks to build a fully connected intelligent ecosystem, driving the evolution of social production and life towards greater efficiency and intelligence. Currently, the IoT is widely used in a variety of fields, including smart homes, industrial automation, smart cities, healthcare, agricultural monitoring, and environmental management, demonstrating its potential for disruptive change.

[0003] The widespread adoption of the IoT exacerbates the challenges of high costs, high energy consumption, and complex communication environments faced in the deployment of the 6th Generation Mobile Communication System (6G). To address this issue, the Reconfigurable Intelligent Surface (RIS), with its disruptive properties of passivity, low power consumption, and low cost, has become a key technology supporting green 6G-IoT communications. RIS consists of an array of passive reflective elements constructed from metamaterials. By dynamically adjusting the phase shift of each element's electromagnetic response, it reconfigures wireless channel propagation characteristics, significantly improving signal coverage and spectral efficiency. Compared to traditional active relays that consume energy for signal regeneration and forwarding, RIS achieves intelligent electromagnetic wave manipulation through passive reflection alone, reducing energy consumption by two orders of magnitude.

[0004] However, traditional RIS is limited by its one-way reflection mechanism, requiring the transmitter and receiver to be located in the same half-space on the same side of the RIS. This can easily lead to communication blind spots in complex environments (such as indoor and outdoor penetration scenarios and urban canyons). To address this limitation, the Transmissive-Reflective Smart Surface (STAR-RIS) was developed. Its duplex electromagnetic metasurface design dynamically splits the incident signal energy, achieving 360° full-scene coverage in two independent spatial dimensions: reflection and transmission, completely eliminating the geometrically constrained blind spots of traditional RIS.

[0005] Cognitive Radio (CR) is a disruptive technology that breaks through the bottleneck of spectrum resource scarcity. Its core lies in achieving interference-free sharing of the secondary network (SN) with the primary network (PN) authorized spectrum through dynamic spectrum sensing and intelligent access decision-making, thereby increasing the utilization rate under traditional static spectrum allocation from less than 15% to over 60%.

[0006] At the same time, the large-scale connection problem faced by IoT has made non-orthogonal multiple access (NOMA) an important candidate technology for 6G due to its ability to support massive device connections. This technology enables multiple users to share the same time domain / frequency domain / code domain resources through power multiplexing and ensures fairness among users. Summary of the Invention

[0007] The present invention aims to provide a STAR-RIS assisted CR-NOMA network and an interruption performance analysis method thereof, so as to provide a wireless network architecture that can expand coverage, reduce system interruption probability, energy consumption and operating costs, and can be widely used in scenarios such as smart cities and industrial Internet of Things. By providing a method for performing interruption performance analysis on the STAR-RIS assisted CR-NOMA wireless network communication architecture, the actual deployment of the STAR-RIS assisted CR-NOMA wireless network communication architecture is analyzed and guided.

[0008] By deeply integrating NOMA, cognitive radio (CR), and simultaneous transflective reflective smart surfaces (STAR-RIS), it is expected to simultaneously achieve 360° full wireless communication coverage, low-power operation (60% reduction in energy consumption), flexible deployment (supporting indoor and outdoor penetration scenarios), and millions of device connections per square kilometer, providing an integrated solution for the 6G smart Internet of Things. However, existing research rarely combines the three. Therefore, to fill this gap, this paper proposes a STAR-RIS-assisted CR-NOMA network and its outage performance analysis method. The STAR-RIS-assisted CR-NOMA network deeply integrates NOMA, cognitive radio (CR), and STAR-RIS technologies, uses secondary user transmitters as PN relays to obtain spectrum usage rights, and evaluates reliability by deriving analytical expressions for primary and secondary user OPs. The asymptotic behavior and diversity order at high SNR are analyzed to deeply understand the network characteristics, providing guidance for the actual deployment of the STAR-RIS-assisted CR-NOMA network.

[0009] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0010] A STAR-RIS-assisted CR-NOMA network outage performance analysis method is provided, including:

[0011] A STAR-RIS-assisted overlay CR-NOMA network communication model is constructed, which includes a primary station PS, a secondary station SS, a STAR-RIS equipped with 2L elements, M secondary users SU and a primary user PU, wherein the M secondary users SU include secondary users SU1 to SU2 located in front of the STAR-RIS. N , and the secondary user SU located at the back side of the STAR-RIS N+1 ~Sub-user SU M The primary station PS, secondary station SS, STAR-RIS, M secondary users SU and primary user PU together constitute a network architecture capable of realizing CR-NOMA network communication. In this network communication model, the secondary station SS receives a signal from the primary station PS, and the secondary station SS sends the same superimposed signal to the primary user PU and each of the secondary users SU through the broadcast feature;

[0012] Solving the received signal signal to noise ratio includes solving the message x of the primary user PU decoded at the secondary station SS. p The signal to interference noise ratio of the primary user PU decodes the message x p Signal to Interference and Noise Ratio; Secondary User SU m (N+1≤m≤M) decode the message x p , secondary user SU m Decoding secondary users Message x j1 (m≤j1≤M) and secondary user SU m The signal to interference and noise ratio of decoding its own message; secondary user SU n (1≤n≤N) decode the message x p Signal to Interference and Noise Ratio, secondary user SU n Decoding secondary users information and secondary user SU n Signal-to-interference-and-noise ratio for decoding its own message;

[0013] Derive the analytical expression of the interruption probability and calculate the interruption probability, including the interruption probability of the primary user PU, the secondary user SU m The interruption probability of the secondary user SU m The probability of interruption.

[0014] Furthermore, the method further includes: determining an asymptotic expression of a high signal-to-noise ratio region, performing asymptotic analysis on the high signal-to-noise ratio region, including performing asymptotic analysis on the high signal-to-noise ratio region of the primary user PU, performing asymptotic analysis on the high signal-to-noise ratio region of the secondary user SU mAsymptotic analysis is performed on the high signal-to-noise ratio region of the secondary user SU n Asymptotic analysis is performed in the high signal-to-noise ratio region.

[0015] Furthermore, it also includes: analyzing the diversity order of users, including analyzing the diversity order of the primary user PU, the secondary user SU m The order of diversity, the secondary users The diversity order of the secondary user SU n The diversity order of the, the diversity order of the and the sub-users order of diversity.

[0016] Furthermore, the signal received by the secondary station SS from the primary station PS is expressed as:

[0017]

[0018] Among them, h ss It is represented as the link channel from the primary station PS to the secondary station SS, P s is the transmission power of the primary station PS, x p is the normalized information of the primary user PU, and E(|x p | 2 )=1,d ss and α ss is the distance and path loss index of the link channel from the primary station PS to the secondary station SS, n1 is complex additive Gaussian white noise;

[0019] When the secondary station SS sends the same superposition signal to the primary user PU and the secondary user SU through the broadcast feature, the secondary user SU located in front of the STAR-RIS n (1≤n≤N) The signal received from the secondary station SS and the signal reflected by the STAR-RIS are:

[0020]

[0021] Among them, h sn It is represented as from the secondary station SS to the secondary user SU n The link channel, h sr Denote the link channel from the secondary station SS to the STAR-RIS, h rn It is represented as from the STAR-RIS to the secondary user SU n Link channel, d sn , d sr , d rn and α st , α sr , α rn Represents SS-SU respectivelyn link, SS-STAR-RIS link, and STAR-RIS-SU n The distance and path loss exponent of the link; x p represents the message of the primary user PU; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; x s,i and b i Denotes the message and power allocation parameters of the ith user, subject to n2 is the complex white Gaussian noise, is the reflection phase shift matrix of STAR-RIS, and represent the amplitude and phase shift of the lth element of STAR-RIS respectively;

[0022] The secondary user SU m The signal received from the STAR-RIS is represented by:

[0023]

[0024] Among them, h sr Denote the link channel from the secondary station SS to the STAR-RIS, h rm It is represented as from the STAR-RIS to the secondary user SU m Link channel, d sr , d rm and α sr , α rm Respectively represent SS-STAR-RIS link and STAR-RIS-SU m The distance and path loss exponent of the link; x p represents the message of the primary user PU; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; x s,i and b i Denotes the message and power allocation parameters of the ith user, subject to is the transmission phase shift matrix of STAR-RIS, and represents the amplitude and phase shift of the lth element of STAR-RIS; n3 is the complex additive Gaussian white noise with an average power of N0;

[0025] The signal received by the primary user PU is expressed as:

[0026]

[0027] Among them, h sr Denote the link channel from the secondary station SS to the STAR-RIS, h rp It is represented as the link channel from the STAR-RIS to the primary user PU; d sr , d rp and α sr , α rp Represent the distance and path loss index of SS-STAR-RIS link and STAR-RIS-PU link respectively; x p represents the message of the primary user PU; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; x s,i and b i Denotes the message and power allocation parameters of the ith user, subject to is the transmission phase shift matrix of STAR-RIS, and represents the amplitude and phase shift of the first element of STAR-RIS; n4 is the complex additive Gaussian white noise with an average power of N0.

[0028] Furthermore, in the calculation of the signal-to-interference-and-noise ratio of the received signal, the decoding of the message x at the secondary station SS is calculated based on the signal received by the secondary station SS from the primary station PS. p The signal-to-interference-and-noise ratio is as follows:

[0029]

[0030] Among them, d ss and α ss is the distance and path loss index of the PS-SS link, P s is the transmission power of the primary station PS; N0 is the average power of the additive Gaussian white noise;

[0031] Based on the signal received by the primary user PU, solve the message x decoded by the primary user PU p The signal-to-interference-and-noise ratio is as follows:

[0032]

[0033] Among them, h sr Denote the link channel from the secondary station SS to the STAR-RIS, h rp Denote the link channel from the STAR-RIS to the primary user PU, d sr , d rp and α sr , αrp P represents the distance and path loss index of SS-STAR-RIS link and STAR-RIS-PU link respectively; s is the transmission power of the primary station PS; a1, a2 represent the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; b i represents the power allocation parameter of the ith user, subject to N0 is the average power of the additive Gaussian white noise; is the transmission phase shift matrix of STAR-RIS, and represents the amplitude and phase shift of the lth element of STAR-RIS;

[0034] Based on the secondary user SU m The signal received from the STAR-RIS is used to solve the secondary user SU m Decode the message x of the primary user PU p , the secondary user News And the signal-to-interference-noise ratio of its own message is as follows:

[0035]

[0036] Among them, h sr Denote the link channel from the secondary station SS to the STAR-RIS, h rp Denote the link channel from the STAR-RIS to the primary user PU, h rm It is represented as from the STAR-RIS to the secondary user SU m Link channel, d sr , d rp , d rm and α sr , α rp , α rm Represents SS-STAR-RIS link, STAR-RIS-PU link and STAR-RIS-SU link respectively m Link distance and path loss index; P s is the transmission power of the primary station PS; a1 and a2 represent the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; is the transmission phase shift matrix of STAR-RIS, and represents the amplitude and phase shift of the lth element of STAR-RIS; represents the power allocation parameter of the j1th secondary user; b mrepresents the power allocation parameter of the mth user; N0 is the average power of the complex additive Gaussian white noise; b q represents the power allocation parameter of the qth secondary user;

[0037] Based on the secondary user SU n (1≤n≤N) receives the signal from the secondary station SS and the signal reflected by the STAR-RIS, and solves the secondary user SU n Decode the primary user PU message x p , the secondary user information And the signal-to-interference-noise ratio of its own message is as follows:

[0038]

[0039] Among them, h sn It is represented as from the secondary station SS to the secondary user SU n The link channel, h sr Denote the link channel from the secondary station SS to the STAR-RIS, h rn It is represented as from the STAR-RIS to the secondary user SU n Link channel, d sn and α sn Represents SS-SU respectively n Link distance and path loss index; P s is the transmission power of the primary station PS; a1 and a2 represent the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; b1<...b n <...b N N+1 <...b m M ; is the reflection phase shift matrix of STAR-RIS, and are the amplitude and phase shift of the first element of STAR-RIS; b i represents the power allocation parameter of the ith user, subject to N0 is the average power of the additive Gaussian white noise; b q represents the power allocation parameter of the qth secondary user.

[0040] Further, based on decoding the message x at the secondary station SS p The signal to interference noise ratio and the primary user PU decoding the message x p ​​The interruption probability of the primary user PU is derived from the signal to interference noise ratio, and in the derivation of the interruption probability of the primary user PU, the secondary station SS and the primary user PU are both able to successfully decode the message x. p When , the primary user PU will not be in an interrupted state. The specific derivation formula is as follows:

[0041]

[0042] in, and

[0043] m ss represents the Nakagami-m fading severity parameter, where m is the mth secondary user number; To detect message x p The target SNR is: N0 is the average power of the additive Gaussian white noise; Ω ss Expressed as the average power of Nakagami-m; d ss and α ss P is the distance and path loss index of the link channel from the primary station PS to the secondary station SS; p is the transmission power of the secondary station SS; d sr , d rp and α sr , α rp denote the distance and path loss index of the SS-STAR-RIS link and the STAR-RIS-PU link respectively; a1, a2 denote the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; P s is the transmission power of the primary station PS; Γ is represented by the gamma function; K p and θ p They represent the shape parameter and scale parameter of the SS-RIS-PU composite link after it is approximated to the Gamma distribution;

[0044] Based on decoding the message x at the secondary station SS p The signal to interference and noise ratio, and the secondary user SU m Decode the message x of the primary user PU p , the secondary user News and the signal to interference noise ratio of its own message to derive the secondary user SU m The interruption probability of the secondary user SU is derived m The interruption probability of the secondary user SU is only when the following conditions are met. m The secondary station SS can successfully decode the message x p ; 2) the secondary user SUm Successfully decode the message x of the primary user PU p ; 3) the secondary user SU m Successfully decoded the secondary user News 4) The secondary user SU m Successfully decoded its own message; details are as follows:

[0045]

[0046] in, and d sr , d rm and α sr , α rm Respectively represent SS-STAR-RIS link and STAR-RIS-SU m Link distance and path loss index; P s is the transmission power of the primary station PS; Γ represents the gamma function; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; To detect message x p Target SNR; To detect messages The target SNR is: N0 is the average power of the additive Gaussian white noise; K x and θ x Represents SS-RIS-SU respectively m The shape and scale parameters of the composite link are approximated to the Gamma distribution;

[0047] Based on decoding the message x at the secondary station SS p The signal to interference and noise ratio, and the secondary user SU n Decode the primary user PU message x p , the secondary user information and the signal to interference noise ratio of its own message to derive the secondary user SU n The interruption probability of the secondary user SU is derived n When the interruption probability is less than 0, the following conditions need to be met: 1) The secondary station SS can successfully decode the message x of the primary user PU p ; 2) SU n Successfully decoded message x p ; 3) the secondary user SU n Successfully decoded the secondary user News 4) The secondary user SU nSuccessfully decoded its own message; details are as follows:

[0048]

[0049] in,

[0050] φ n 、 are all expressed as a mathematical operation, expressed as γ represents the lower half of the incomplete gamma function; h sr Denote the link channel from the secondary station SS to the STAR-RIS, h rn It is represented as from the STAR-RIS to the secondary user SU n Link channel; m sr Expressed as the Nakagami-m fade severity parameter from the secondary station SS to STAR-RIS; m rn From STAR-RIS to secondary user SU n Nakagami-m fading severity parameter; d sn and α sn Represents SS-SU respectively n Link distance and path loss index; P s is the transmission power of the primary station PS; Γ represents the gamma function; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; To detect message x p Target SNR; To detect messages The target SNR is: N0 is the average power of the complex additive Gaussian white noise; K1 is the index of the variable in the finite summation, ranging from 0< <K1<<m ss -1;m ss represents the Nakagami-m fade severity parameter; represents the power allocation parameter of the j2th secondary user; b i represents the power allocation parameter of the ith user, subject to

[0051] Furthermore, in the asymptotic analysis of the high signal-to-noise ratio region, based on the derived interruption probability of the primary user PU, an asymptotic expression of the high signal-to-noise ratio region is determined for analysis, wherein the asymptotic expression of the high signal-to-noise ratio region of the primary user PU is specifically as follows:

[0052]

[0053] in, d sr , d rp and α sr , α rp denote the distance and path loss index of the SS-STAR-RIS link and the STAR-RIS-PU link, respectively; a1 and a2 denote the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1 ≥ a2, a1 + a2 = 1; To detect message x p Target SNR; K p and θ p They represent the shape parameter and scale parameter of the SS-RIS-PU composite link after it is approximated to the Gamma distribution;

[0054] Based on the derived secondary user SU m The interruption probability of the secondary user SU m The asymptotic expression of the high signal-to-noise ratio region is as follows:

[0055]

[0056] in, and d sr , d rm and α sr , α rm Respectively represent SS-STAR-RIS link and STAR-RIS-SU m Link distance and path loss index; a1, a2 represent the power allocation parameters for messages from the primary user PU and the secondary user, satisfying a1≥a2, a1+a2=1; To detect message x p Target SNR; K x and θ x Represents SS-RIS-SU respectively m The shape and scale parameters of the composite link are approximated to the Gamma distribution;

[0057] Based on the derived secondary user SU n The interruption probability of the secondary user SU n The asymptotic expression of the high signal-to-noise ratio region is as follows:

[0058]

[0059] in,

[0060] m ss represents the Nakagami-m fading severity parameter, where m is the mth secondary user number; γ represents the lower half of the incomplete gamma function; k1; d sn and α sn Represents SS-SU respectively n Link distance and path loss index; P s is the transmission power of the primary station PS; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; To detect message x p Target SNR; b i represents the power allocation parameter of the ith user, subject to To detect messages Target SNR; represents the power allocation parameter of the j2th secondary user.

[0061] Furthermore, in analyzing the diversity order of users, the diversity order of users is first analyzed by defining an equation as shown below:

[0062]

[0063] in, P s is the transmission power of the primary station PS; N0 is the average power of the additive white Gaussian noise; Shown is the asymptotic expression for the high signal-to-noise ratio region;

[0064] Then the diversity order of the primary user PU is analyzed, and the secondary user SU m The diversity order of the secondary users The diversity order of the secondary user SU n The order of diversity and the secondary users The diversity order of is expressed as follows:

[0065]

[0066] Among them, d PU It is represented as the diversity order of the primary user PU, Denoted as the secondary user SU m The order of diversity, Denoted as the secondary user SU n The order of diversity, Denoted as the secondary user SUj2 order of diversity.

[0067] The present invention also provides a STAR-RIS assisted CR-NOMA network, which includes a primary station PS, a secondary station SS, a STAR-RIS equipped with 2L elements, M secondary users SU and a primary user PU, wherein the M secondary users SU include secondary users SU1 to SU2 located in front of the STAR-RIS. N , and the secondary user SU located at the back side of the STAR-RIS N+1 ~Sub-user SU M The primary station PS, secondary station SS, STAR-RIS, M secondary users SU and primary user PU together constitute a network architecture capable of realizing CR-NOMA network communication. In the STAR-RIS assisted CR-NOMA network, the secondary station SS receives a signal from the primary station PS, and the secondary station SS sends the same superimposed signal to the primary user PU and each of the secondary users SU through the broadcast characteristics; the STAR-RIS assisted CR-NOMA network is deployed based on the analysis method of the interruption performance analysis of the STAR-RIS assisted CR-NOMA network described in any of the preceding items.

[0068] Compared with the prior art, the beneficial effects of the present invention are as follows: the interruption performance analysis method of the STAR-RIS-assisted CR-NOMA network includes constructing a new passive STAR-RIS-assisted coverage CR-NOMA network communication model, solving the received signal signal to noise ratio, deriving an analytical expression for the interruption probability, determining the asymptotic expression of the high signal to noise ratio area, and analyzing the user's diversity order. It innovatively combines STAR-RIS, RSMA and cognitive radio to enhance spectrum efficiency, communicates with users with the help of passive STAR-RIS, and derives the user's interruption probability under the Nakagami-mm fading channel, analyzes the asymptotic behavior of the high signal to noise ratio area, and thus improves the practicality of guiding the deployment of wireless network systems. By guiding the deployment of wireless network systems through the interruption performance analysis method of the STAR-RIS-assisted CR-NOMA network, it can solve the problems of small wireless network coverage, low deployment flexibility, high cost and power consumption, improve spectrum utilization, expand coverage, reduce the interruption probability, energy consumption and operating cost of the wireless network system, and can be widely used in scenarios such as smart cities and industrial Internet of Things to meet the urgent demand for low-cost and low-power communication. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] The present invention is explained in detail below based on the accompanying drawings. It should be noted that the accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention, but they cannot create any limitation on the feasibility of the present invention.

[0070] In the attached figure:

[0071] Figure 1 Flowchart of an embodiment of a method for analyzing outage performance of a STAR-RIS-assisted CR-NOMA network according to the present invention.

[0072] Figure 2 This is an architectural diagram of a new passive STAR-RIS-assisted overlay CR-NOMA network communication model constructed in an embodiment of the STAR-RIS-assisted CR-NOMA network interruption performance analysis method of the present invention.

[0073] Figure 3 The interruption probability of different users and the transmission power P of the primary station PS in the first embodiment of the interruption performance analysis method of the STAR-RIS assisted CR-NOMA network of the present invention are shown in FIG. s relationship diagram.

[0074] Figure 4 This is a comparison chart of the impact of the number of STAR-RIS components on system reliability in an embodiment of the STAR-RIS-assisted CR-NOMA network interruption performance analysis method of the present invention. DETAILED DESCRIPTION

[0075] The following will be combined with the accompanying drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the embodiments described are only part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0076] In addition, as shown in the present disclosure and claims, unless the context clearly indicates an exception, the words "a", "an", "an kind" and / or "the" do not specifically refer to the singular, but also include the plural. The "first", "second" and similar words used in the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. The directions or positional relationships indicated by the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present application.

[0077] In one embodiment, a method for analyzing the interruption performance of a STAR-RIS-assisted CR-NOMA network is provided, such as Figure 1 As shown, the STAR-RIS-assisted CR-NOMA network outage performance analysis method includes:

[0078] Step S100: Constructing a new passive STAR-RIS-assisted coverage CR-NOMA network communication model

[0079] In the steps of constructing the STAR-RIS-assisted overlay CR-NOMA network communication model, Figure 2 As shown, the network communication model includes a primary station PS110, a secondary station SS120, a STAR-RIS130 equipped with 2L elements, M secondary users SU and a primary user PU 150. The M secondary users SU include a front-side user 140a and a back-side user 140b. The front-side user 140a is a secondary user SU1 located at the front side of the STAR-RIS. N , the backside user 140b is a secondary user SU located at the backside of STAR-RIS N+1 ~Sub-user SU M The primary station PS110, the secondary station SS120, the STAR-RIS130, the M secondary users SU and the primary user PU150 together constitute a network architecture that can realize CR-NOMA network communication. In this network communication model, the secondary station SS120 receives the signal from the primary station PS110, and the secondary station SS120 sends the same superimposed signal to the primary user PU 150 and each secondary user SU through the broadcast feature.

[0080] In this network communication model, overlay CR-NOMA network communication utilizes spectrum holes. Secondary stations SS120 act as relays in the primary network, where primary station PS110 resides, in exchange for spectrum usage rights and information forwarding. This improves the performance of the primary network where primary station PS110 resides while enabling parallel transmission between the primary and secondary networks constructed by secondary station SS120. As long as the authorized spectrum of primary station PS110 is unoccupied, secondary station SS120 can access communications. STAR-RIS130 (equipped with 2L elements) is a transflective smart surface designed to improve spectrum efficiency and enhance network system performance. The 2L elements of STAR-RIS130 are divided into two equal parts: L for reflection and the remaining L for transmission. Primary user PU150 is a user with authorized spectrum usage rights and communication priority. Secondary users SU are unauthorized users and need to dynamically monitor the spectrum status of primary user PU150. They adjust their own parameters (such as transmit power and modulation mode) to communicate only when the spectrum is idle. They must actively exit the spectrum when the primary user reoccupies the spectrum. The secondary station SS120 transmits the same superposition signal to the primary user PU 150 and each secondary user SU through the broadcast feature. The superposition signal refers to the signal broadcast by the secondary station SS, which is the superposition of the message of the primary user PU and the message of the i-th secondary user. For example, for the signal y broadcast by the secondary station SS ss , the signal y ss At the secondary station SS, it is the message x of the primary user PU. p and the message x of the i-th secondary user i of superposition.

[0081] Step S200: Calculate the signal-to-interference-and-noise ratio of the received signal

[0082] The step of solving the signal-to-interference-and-noise ratio of the received signal includes solving the message x of the primary user PU decoded at the secondary station SS. p Signal to Interference and Noise Ratio; Primary user PU decodes message x p Signal to Interference and Noise Ratio; Secondary User SU m (N+1≤m≤M) decode message x p , secondary user SU m Decoding secondary users News and secondary user SU m The signal to interference and noise ratio of decoding its own message; secondary user SU n (1≤n≤N) decode message x p Signal to Interference and Noise Ratio, secondary user SU n Decoding secondary users information and secondary user SU n The signal-to-interference-and-noise ratio for decoding its own message.

[0083] Here the message x of the primary user PU p Refers to the normalized information of the primary user PU, which is E(|x p | 2 ) = 1. The normalized information of the primary user PU refers to the primary user signal characteristics after normalization. The normalization operation adjusts the minimum signal value to the lower limit of the interval (such as 0 or -1), the maximum value to the upper limit of the interval (such as 1), and other values ​​are scaled proportionally. This has the advantages of facilitating comparison and simplifying processing during performance analysis. It is a common processing method in the communications field.

[0084] Step S300: Derive the analytical expression of the outage probability

[0085] By deriving the analytical expression of the outage probability, the outage probability is calculated, including the outage probability of the primary user PU, the outage probability of the secondary user SU m The interruption probability and secondary user SU m The probability of interruption.

[0086] By calculating the interruption probability of different users, the reliability of the network communication model can be reflected. By reducing the interruption probability, the reliability and stability of the network system can be improved to meet the needs of various application scenarios.

[0087] Step S400: Determine the asymptotic expression for high signal-to-noise ratio regions

[0088] The step of determining the asymptotic expression of the high signal-to-noise ratio region is to perform asymptotic analysis on the high signal-to-noise ratio region, including performing asymptotic analysis on the high signal-to-noise ratio region of the primary user PU and performing asymptotic analysis on the high signal-to-noise ratio region of the secondary user SU. m Asymptotic analysis of the high signal-to-noise ratio region and the secondary user SU n Asymptotic analysis is performed in the high signal-to-noise ratio region.

[0089] In step S300, the outage probabilities for primary and secondary users are derived by deriving analytical expressions for the outage probability, enabling network outage performance analysis. However, in complex communication scenarios (such as CR-NOMA), closed-form expressions cannot be obtained due to the coupling of multi-user interference and non-ideal factors, hindering accurate performance analysis and theoretical verification of communication performance. Therefore, step S300 is applicable to simplified scenarios. While the asymptotic analysis of the high signal-to-noise ratio (SNR) region in step S400 does not cover the full SNR (signal-to-noise ratio) range, it can reveal the essential characteristics of the system with low complexity and guide practical deployment. The asymptotic analysis of the high SNR region in step S400 has the following advantages: First, it can ignore complex interference terms at low SNRs, extract the dominant factors, and provide simple rules for system design. Second, the asymptotic results are generally insensitive to specific parameter settings, making them more widely applicable. Third, high SNRs correspond to scenarios where the base station is close to users or has high transmit power, providing guidance for practical deployment and resolving issues in actual network deployment.

[0090] Step S500: Analyze the user's diversity order

[0091] The step of analyzing the user's diversity order includes analyzing the diversity order of the primary user PU, the secondary user SU m Diversity order, secondary users Diversity order, secondary user SU n The diversity order of the, the diversity order of the and the secondary users order of diversity.

[0092] In step S500, the purpose of analyzing the diversity order of users is to analyze the robustness of the network system model against channel fading. Under high signal-to-noise ratio, the diversity order determines whether the system can support higher-order modulation (such as 256-QAM) while maintaining a low error probability, thereby improving spectrum efficiency. At the same time, the network communication model constructed by this method involves a lower diversity order, which is more suitable for scenarios with good channel conditions and limited complexity. In wireless communication systems, the diversity order is a key indicator to measure the system's ability to resist channel fading, and directly affects the reliability of communication. Its physical meaning is: the diversity order d means that when the SNR increases by 10dB, the interruption probability decreases by 10d times. For example, if d = 2, the interruption probability decreases by about 100 times for every 10dB increase in SNR.

[0093] This STAR-RIS-assisted CR-NOMA network outage performance analysis method involves constructing a new passive STAR-RIS-assisted coverage CR-NOMA network communication model, solving the received signal-to-interference-and-noise ratio (SINR), deriving an analytical expression for the outage probability, determining the asymptotic expression for the high SNR region, and analyzing the user diversity order. This method innovatively combines STAR-RIS, RSMA, and cognitive radio to enhance spectrum efficiency. By leveraging passive STAR-RIS to communicate with users, the method derives the user outage probability under a Nakagami-mm fading channel and analyzes the asymptotic behavior in the high SNR region, thereby enhancing the practicality of guidance for wireless network system deployment. Using this STAR-RIS-assisted CR-NOMA network outage performance analysis method to guide wireless network system deployment can address issues such as limited wireless network coverage, low deployment flexibility, and high cost and power consumption. It improves spectrum utilization, expands coverage, and reduces the outage probability, energy consumption, and operating costs of wireless network systems. This method is widely applicable in scenarios such as smart cities and the Industrial Internet of Things, meeting the urgent need for low-cost, low-power communications.

[0094] Furthermore, in the previous step S100 of the STAR-RIS assisted CR-NOMA network outage performance analysis method, the signal received by the secondary station SS from the primary station PS is represented as:

[0095]

[0096] Among them, h ss It is represented as the link channel from the primary station PS to the secondary station SS, P s is the transmission power of the primary station PS, x p is the normalized information of the primary user PU, and E(|x p | 2 )=1,d ss and α ss is the distance and path loss index of the link channel from the primary station PS to the secondary station SS, and n1 is the additive white Gaussian noise (AWGN).

[0097] When the secondary station SS sends the same superposition signal to the primary user PU and the secondary user SU through the broadcast feature, the secondary user SU located in front of the STAR-RIS n (1≤n≤N) The signal received from the secondary station SS and the signal reflected by STAR-RIS are:

[0098]

[0099] Among them, h sn Represented as from the secondary station SS to the secondary user SUn The link channel, h sr Denote the link channel from the secondary station SS to STAR-RIS, h rn Represented as from STAR-RIS to secondary user SU n Link channel, d sn , d sr , d rn and α st , α sr , α rn Represents SS-SU respectively n link, SS-STAR-RIS link, and STAR-RIS-SU n The distance and path loss exponent of the link; x p represents the message of the primary user PU; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; x s,i and b i Denotes the message and power allocation parameters of the ith user, subject to n2 is the complex white Gaussian noise, is the reflection phase shift matrix of STAR-RIS, and They represent the amplitude and phase shift of the first element of STAR-RIS respectively.

[0100] In the reflection phase shift matrix here, the number of STAR-RIS elements is 2L, of which L elements are used for reflection and the remaining L elements are used for transmission. The L in the reflection phase shift matrix represents the elements of the L elements used for reflection.

[0101] Secondary User SU m The signal received from STAR-RIS is represented by:

[0102]

[0103] Among them, h sr Denote the link channel from the secondary station SS to STAR-RIS, h rm Represented as from STAR-RIS to secondary user SU m Link channel, d sr , d rm and α sr , α rm Respectively represent SS-STAR-RIS link and STAR-RIS-SU m The distance and path loss exponent of the link; x prepresents the message of the primary user PU; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; x s,i and b i Denotes the message and power allocation parameters of the ith user, subject to is the transmission phase shift matrix of STAR-RIS, and represents the amplitude and phase shift of the lth element of STAR-RIS; n3 is the complex additive Gaussian white noise with an average power of N0;

[0104] In the transmission phase shift matrix here, the number of STAR-RIS elements is 2L, of which L elements are used for reflection and the remaining L elements are used for transmission. The L in the transmission phase shift matrix represents the elements of the L elements used for transmission.

[0105] The signal received by the primary user PU is expressed as:

[0106]

[0107] Among them, h sr Denote the link channel from the secondary station SS to STAR-RIS, h rp It is represented as the link channel from STAR-RIS to the primary user PU; d sr , d rp and α sr , α rp Represent the distance and path loss index of SS-STAR-RIS link and STAR-RIS-PU link respectively; x p represents the message of the primary user PU; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; x s,i and b i Denotes the message and power allocation parameters of the ith user, subject to is the transmission phase shift matrix of STAR-RIS, and represents the amplitude and phase shift of the first element of STAR-RIS; n4 is the complex additive Gaussian white noise with an average power of N0.

[0108] For the above parameters n1, n2, n3, n4, n1 represents the complex white Gaussian noise at the secondary station SS; n2 represents the secondary user SU n The complex additive Gaussian white noise at n3 represents the secondary user SU mn4 represents the complex Gaussian white noise at the receiving end of the primary user PU. When each user receives the signal sent by the previous stage, it will receive additional interference signals, collectively referred to as complex Gaussian white noise.

[0109] Through steps (1)-(4), the signal received by the secondary station SS from the primary station PS and the secondary user SU are obtained. n (1≤n≤N) receives the signal from the secondary station SS and the signal reflected by STAR-RIS, the secondary user SU m The signals received from STAR-RIS and the primary user PU provide basic data for subsequent steps.

[0110] Furthermore, in step S200 of the STAR-RIS assisted CR-NOMA network outage performance analysis method, in solving the received signal signal to interference and noise ratio, based on the signal received by the secondary station SS from the primary station PS, the decoded message x at the secondary station SS is solved. p The signal-to-interference-and-noise ratio is as follows:

[0111]

[0112] Among them, d ss and α ss is the distance and path loss index of the PS-SS link, P s is the transmission power of the primary station PS; N0 is the average power of the additive Gaussian white noise.

[0113] Here, the signal-to-interference-and-noise ratio is: SINR = S / (I+N), where signal power S refers to the average power of the target signal at the receiving end, which is usually related to factors such as transmit power, channel gain, and path loss; interference power I is the interference power from other non-target signal sources (such as signals generated by other users in the same frequency band, adjacent base stations, or devices); and noise power N is the thermal noise inside the system or in the environment (such as Gaussian white noise), which is usually related to receiver performance and bandwidth. This formula (5) represents the solution for the decoded message x at the secondary station SS. p The result of the signal to interference and noise ratio of formula (5) is obtained by calculating the signal received by the secondary station SS from the primary station PS in formula (1). The specific method is to use the square of the norm (the conventional method for calculating the signal to interference and noise ratio in the communication field. Because the calculation process is general knowledge, the result of the solution is directly retained here without giving the specific calculation process).

[0114] Based on the signal received by the primary user PU, solve the primary user PU decoding message x p The signal-to-interference-and-noise ratio is as follows:

[0115]

[0116] Among them, h sr Denote the link channel from the secondary station SS to STAR-RIS, h rp Denote the link channel from STAR-RIS to the primary user PU, d sr , d rp and α sr , α rp P represents the distance and path loss index of SS-STAR-RIS link and STAR-RIS-PU link respectively; s is the transmission power of the primary station PS; a1, a2 represent the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; b i represents the power allocation parameter of the ith user, subject to N0 is the average power of the additive Gaussian white noise; is the transmission phase shift matrix of STAR-RIS, and Represents the amplitude and phase shift of the lth element of STAR-RIS.

[0117] Similarly, formula (6) represents the solution of the primary user PU decoding message x p The result of the signal to interference and noise ratio of formula (6) is obtained by calculating the signal received by the primary user PU in formula (4), and the specific method is to use the square of the norm.

[0118] Based on secondary user SU m The signal received from STAR-RIS is used to solve the secondary user SU m Decode the message x of the primary user PU p , secondary users News And the signal-to-interference-noise ratio of its own message is as follows:

[0119]

[0120] Among them, h sr Denote the link channel from the secondary station SS to STAR-RIS, h rp Denote the link channel from STAR-RIS to the primary user PU, h rm Represented as from STAR-RIS to secondary user SU m Link channel, d sr , d rp , d rm and α sr , α rp , α rmRepresents SS-STAR-RIS link, STAR-RIS-PU link and STAR-RIS-SU link respectively m Link distance and path loss index; P s is the transmission power of the primary station PS; a1 and a2 represent the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; is the transmission phase shift matrix of STAR-RIS, and represents the amplitude and phase shift of the lth element of STAR-RIS; represents the power allocation parameter of the j1th secondary user; b m represents the power allocation parameter of the mth user; N0 is the average power of the complex additive Gaussian white noise; b q represents the power allocation parameter of the qth secondary user;

[0121] The formulas (7)-(9) respectively represent the solutions for the secondary user SU m Decode the message x of the primary user PU p , secondary users News and the signal-to-interference-noise ratio of its own message, the results of formulas (7)-(9) are obtained by calculating the secondary user SU in formula (3) m Calculated from the signal received by STAR-RIS.

[0122] Based on secondary user SU n (1≤n≤N) receives the signal from the secondary station SS and the signal reflected by STAR-RIS, and solves the secondary user SU n Decode the primary user PU message x p , secondary user information And the signal-to-interference-noise ratio of its own message is as follows:

[0123]

[0124] Among them, h sn Represented as from the secondary station SS to the secondary user SU n The link channel, h sr Denote the link channel from the secondary station SS to STAR-RIS, h rn Represented as from STAR-RIS to secondary user SU n Link channel, d sn and α sn Represents SS-SU respectively n Link distance and path loss index; P sis the transmission power of the primary station PS; a1 and a2 represent the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; b1<...b n <...b N N+1 <...b m M ; is the reflection phase shift matrix of STAR-RIS, and are the amplitude and phase shift of the first element of STAR-RIS; b i represents the power allocation parameter of the ith user, subject to N0 is the average power of the additive Gaussian white noise; b q represents the power allocation parameter of the qth secondary user.

[0125] The formulas (10)-(12) respectively represent the solutions for the secondary user SU n Decode the primary user PU message x p , secondary user information and the signal-to-interference-noise ratio of its own message, the results of formulas (10)-(12) are obtained by calculating the secondary user SU in formula (2) n (1≤n≤N) is calculated by receiving the signal from the secondary station SS and the signal reflected by STAR-RIS.

[0126] Furthermore, in the above step S300 of the STAR-RIS assisted CR-NOMA network outage performance analysis method, based on the decoding message x at the secondary station SS, p The signal-to-interference-noise ratio and the primary user PU decoding message x p The interruption probability of the primary user PU is derived from the signal-to-interference-noise ratio. In the derivation of the interruption probability of the primary user PU, only when both the secondary station SS and the primary user PU successfully decode the message x p When the primary user PU is not in an interrupted state, the specific derivation formula is as follows:

[0127]

[0128] in, and

[0129] m ss represents the Nakagami-m fading severity parameter, where m is the mth secondary user number; To detect message x p The target SNR is: N0 is the average power of the additive Gaussian white noise; Ω​​ss Expressed as the average power of Nakagami-m; d ss and α ss is the distance and path loss index of the link channel from the primary station PS to the secondary station SS; P p is the transmission power of the secondary station SS; d sr , d rp and α sr , α rp denote the distance and path loss index of the SS-STAR-RIS link and the STAR-RIS-PU link respectively; a1, a2 denote the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; P s is the transmission power of the primary station PS; Γ is represented by the gamma function; K p and θ p They represent the shape parameter and scale parameter of the SS-RIS-PU composite link after it is approximated to the Gamma distribution.

[0130] parameter Is the detection message x p The target SNR is, where In order to detect the preset transmission rate of the message, this method can be used to verify the Set to 0.009.

[0131] Formula (13) here is the result of the derived interruption probability of the primary user PU. In the calculation, the interruption probability of the primary user PU is expressed as:

[0132]

[0133] in, Decode message x at secondary station SS p The signal-to-interference-noise ratio is (5). Is the detection message x p The target SNR of this method is Set to 0.009; γ pu Decode message x for the primary user PU p signal-to-interference-noise ratio.

[0134] The process of deriving the interruption probability of the primary user PU is as follows:

[0135] First, the channel statistics are obtained by moment matching method to analyze the interruption probability of the primary user PU. The distribution of Y can be approximated as Y~Γ(K Y ,θ Y), the PDF (probability density function) of Y can be expressed as:

[0136]

[0137] in,

[0138] In particular, the channel statistics of the primary user PU and the secondary user SU m same.

[0139] Secondly, the series form of Laguerre polynomials is used to obtain channel statistics, and the results are used to discuss the outage probability of users, as follows:

[0140] 1) Let X = h sr ||h rn |, the PDF of the concatenated channel X can be expressed as:

[0141]

[0142] 2) Further, suppose

[0143] 3) Since it is difficult to obtain the PDF (probability density function) of S from the above formula, the PDF of S is obtained through the series form of Laguerre polynomials, as follows:

[0144]

[0145] in,

[0146] The parameter Y above is represented by h sr The norm of the link channel from the secondary station SS to STAR-RIS is related to h rm (From STAR-RIS to secondary user SU m The accumulation of the product of the link channel) norm; S is represented by h sr The norm of the link channel from the secondary station SS to STAR-RIS is related to h rn (From STAR-RIS to secondary user SU n The accumulation of the products of the link channel) norms.

[0147] Next, the interruption probability of the primary user PU is derived as follows:

[0148] 1) Only when both the secondary station SS and the primary user PU successfully decode the message x p When the primary user PU is not in an interrupted state, the interruption probability of the primary user PU is:

[0149]

[0150] 2) Decode the message x at the secondary station SS p The signal-to-interference-noise ratio and the primary user PU decoding message x p By bringing the signal-to-interference-and-noise ratio into the above formula, the outage probability of the primary user PU can be further expressed as:

[0151]

[0152] 3) Channel |h ss | 2 The PDF can be expressed as:

[0153]

[0154] Among them, m ss represents the Nakagami-m fading severity parameter, Ω ss Expressed as the average power of Nakagami-m.

[0155] 4) Set channel|h ss | 2 The PDF of is then brought back into the interruption probability of the primary user PU, which is further expressed as:

[0156]

[0157] in, and

[0158] Based on the decoded message x at the secondary station SS p Signal to Interference and Noise Ratio, and secondary user SU m Decode the message x of the primary user PU p , secondary users News and the signal-to-interference-noise ratio of its own message to derive the secondary user SU m The interruption probability of the secondary user SU is derived m The interruption probability of the secondary user SU is only when the following conditions are met. m The interruption is not in shutdown state: 1) The secondary station SS can successfully decode the message x p ; 2) Secondary user SU m Successfully decoded the message x of the primary user PU p ; 3) Secondary user SU m Successfully decoded secondary user News 4) Secondary User SU m Successfully decoded its own message; details are as follows:

[0159]

[0160] in, and d sr , d rm and α sr , α rm Respectively represent SS-STAR-RIS link and STAR-RIS-SU m Link distance and path loss index; P s is the transmit power of the primary station PS; Γ is represented by the gamma function; a1 and a2 represent the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; To detect message x p Target SNR; To detect messages The target SNR is: N0 is the average power of the additive Gaussian white noise; K x and θ x Represents SS-RIS-SU respectively m The shape and scale parameters of the composite link are approximated as Gamma distribution.

[0161] Here we derive the secondary user SU m The interruption probability is also derived based on the previous calculation results.

[0162] Secondary User SU m The derivation process of the interruption probability is as follows:

[0163] 1) Secondary User SU m The interruption probability is:

[0164]

[0165] in, and E ss,p and E sm,p Represents the secondary station SS and the secondary user SU m Successfully decoded the message x of the primary user PU p . E sm,j1 Indicates secondary user SU m Successfully decoded the secondary user The message xj1, represents the target signal-to-noise ratio for detecting message xj1.

[0166] 2) In Nakagami-m fading channel, the next user SU m The analytical expression of the outage probability is expressed as:

[0167]

[0168] in, and

[0169] Based on the decoded message x at the secondary station SS p Signal to Interference and Noise Ratio, and secondary user SU n Decode the primary user PU message x p , secondary user information and the signal-to-interference-noise ratio of its own message to derive the secondary user SU n The interruption probability of the secondary user SU is derived n When the interruption probability is high, the following conditions need to be met: 1) The secondary station SS can successfully decode the message x of the primary user PU p ; 2) SU n Successfully decoded message x p ; 3) Secondary user SU n Successfully decoded the secondary user News 4) Secondary User SU n Successfully decoded its own message; details are as follows:

[0170]

[0171] in,

[0172] φ n 、 are expressed as a mathematical operation, expressed as γ represents the lower half of the incomplete gamma function; h sr Denote the link channel from the secondary station SS to STAR-RIS, h rn Represented as from STAR-RIS to secondary user SU n Link channel; m sr Expressed as the Nakagami-m fade severity parameter from the secondary station SS to STAR-RIS; m rn From STAR-RIS to secondary user SU n Nakagami-m fading severity parameter; d sn and α sn Represents SS-SU respectively n Link distance and path loss index; P s is the transmit power of the primary station PS; Γ is represented by the gamma function; a1 and a2 represent the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; To detect message x p Target SNR; To detect messages The target SNR is: N0 is the average power of the complex additive Gaussian white noise; K1 is the index of the variable in the finite summation, ranging from 0 << K1 << m ss -1;m ss represents the Nakagami-m fade severity parameter; represents the power allocation parameter of the j2th secondary user; b i represents the power allocation parameter of the ith user, subject to

[0173] Here we derive the secondary user SU n The interruption probability is also derived based on the previous calculation results. Among them, the previous formulas (1)-(4) are for signal transmission of the constructed communication model and are the basis of all calculations; the quality of the transmitted signal is calculated through formulas (5)-(11), that is, the signal-to-interference-and-noise ratio of the signal transmission is solved, which is also the premise for calculating the interruption probability; then the signal-to-interference-and-noise ratio is used to solve the interruption probability of formulas (12)-(15).

[0174] Secondary User SU n The outage probability is calculated as follows:

[0175]

[0176] in, E sn,p Indicates SU n Successfully decoded the message x of the primary user PU p , and E sn,j2 Indicates SU n Successful decoding Message x j2 , Represents a user Detection message x j2 target signal-to-noise ratio.

[0177] 2) Channel h sn The PDF can be expressed as:

[0178]

[0179] 3) Assume that Z = (|h sn |+S) 2 , the PDF expression of Z can be expressed as:

[0180]

[0181] The parameter Z here is represented by hsn (From the secondary station SS to the secondary user SU n The link channel) norm and the square of S are commonly used methods to solve the interruption probability in the field of communications.

[0182] 4) According to the PDF expression of S, h sn The PDF expression of , the PDF expression of Z can be obtained as follows: n The analytical expression of the interruption probability is as follows:

[0183]

[0184] Furthermore, in step S400 of the STAR-RIS assisted CR-NOMA network outage performance analysis method, an asymptotic analysis is performed on the high signal-to-noise ratio region. Based on the derived outage probability of the primary user PU, an asymptotic expression of the high signal-to-noise ratio region is determined for analysis. The asymptotic expression of the high signal-to-noise ratio region of the primary user PU is specifically as follows:

[0185]

[0186] in, d sr , d rp and α sr , α rp denote the distance and path loss index of the SS-STAR-RIS link and the STAR-RIS-PU link, respectively; a1 and a2 denote the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1 ≥ a2, a1 + a2 = 1; To detect message x p Target SNR; K p and θ p They represent the shape parameter and scale parameter of the SS-RIS-PU composite link after it is approximated to the Gamma distribution;

[0187] The asymptotic expression for analyzing the high SNR region of the primary user PU in formula (16) is calculated based on the results obtained from the previous formula. In complex communication scenarios (such as CR-NOMA), due to the coupling of multi-user interference and non-ideal factors, a closed-form expression cannot be obtained, which will affect the accurate performance analysis and theoretical verification of communication performance. It is only applicable to simplified scenarios. Therefore, asymptotic analysis of the high SNR region has become an important alternative. Although it cannot cover the entire SNR range, it can reveal the essential characteristics of the system with low complexity and guide actual deployment. Therefore, the outage probability is used here to solve the asymptotic expression of the high SNR region.

[0188] Based on the derived secondary user SUm The interruption probability of the secondary user SU m The asymptotic expression of the high signal-to-noise ratio region is as follows:

[0189]

[0190] in, and d sr , d rm and α sr , α rm Respectively represent SS-STAR-RIS link and STAR-RIS-SU m Link distance and path loss index; a1, a2 represent the power allocation parameters for messages from the primary user PU and the secondary user, satisfying a1≥a2, a1+a2=1; To detect message x p Target SNR; K x and θ x Represents SS-RIS-SU respectively m The shape and scale parameters of the composite link are approximated as Gamma distribution.

[0191] Similarly, the formula (17) calculates the secondary user SU m The asymptotic expression of the high signal-to-noise ratio region is also calculated based on the results obtained from the previous formula.

[0192] Based on the derived secondary user SU n The interruption probability of the secondary user SU n The asymptotic expression of the high signal-to-noise ratio region is as follows:

[0193]

[0194] in,

[0195] m ss represents the Nakagami-m fading severity parameter, where m is the mth secondary user number; γ represents the lower half of the incomplete gamma function; k1; d sn and α sn Represents SS-SU respectively n Link distance and path loss index; P s is the transmission power of the primary station PS; a1 and a2 represent the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; To detect message x p Target SNR; b i represents the power allocation parameter of the ith user, subject to To detect messages Target SNR; represents the power allocation parameter of the j2th secondary user.

[0196] Similarly, the formula (18) calculates the secondary user SU n The asymptotic expression of the high signal-to-noise ratio region is also calculated based on the results obtained from the previous formula.

[0197] Furthermore, in step S500 of the STAR-RIS assisted CR-NOMA network outage performance analysis method, the diversity order of the user is analyzed by first defining an equation, as shown below:

[0198]

[0199] in, P s is the transmission power of the primary station PS; N0 is the average power of the additive Gaussian white noise; Shown are the asymptotic expressions for the high signal-to-noise ratio region.

[0200] Formula (19) here gives a specific formula for analyzing the user diversity order. To solve the user diversity order, it is necessary to calculate it based on the asymptotic expression of the high signal-to-noise ratio region calculated previously.

[0201] Then analyze the diversity order of primary user PU, secondary user SU m Diversity order, secondary users The diversity order of the secondary user SU n Diversity order and secondary users The diversity order of is expressed as follows:

[0202]

[0203] Among them, d PU Indicates the diversity order of the primary user PU, Represented as secondary user SU m The order of diversity, Represented as secondary user SU n The order of diversity, Represented as secondary user SU j2 order of diversity.

[0204] Formula (19) is a specific formula for analyzing the user diversity order, and formula (20) is calculated using formula (19), where is expressed as an asymptotic expression in the high signal-to-noise ratio region, so After substituting into formula (19), the diversity order of each user can be solved.

[0205] Among them, the asymptotic expression of the interruption probability of the primary user PU in the high signal-to-noise ratio area is analyzed. After substituting it into the above formula, the diversity order of the primary user PU is obtained as d PU = 0. Analysis of secondary user SU m The asymptotic expression of the outage probability in the high SNR area is substituted into the above formula to obtain the secondary user SU m The diversity order is

[0206] Finally, analyze the secondary user SU n The asymptotic expression of the outage probability in the high SNR region is substituted into the above expression to obtain the user SU n The diversity order is

[0207] Combine Figure 3 and Figure 4 As shown in the figure, the Simulation (simulation) is the operation process of the communication system constructed by computer modeling and numerical experimental simulation to generate statistical samples to evaluate performance indicators. The Monte Carlo method is commonly used to approximate the actual performance through a large number of repeated experiments. Analytical (analysis) is based on mathematical derivation to directly derive the analytical solution of the performance indicator to provide a rapid evaluation, and its effectiveness is verified by simulation. The Analytical (analysis) here verifies the performance of the analysis system by deriving the analytical expression of the interruption probability through computer simulation. The performance behavior of the constructed system by Asymptotic (asymptotic) when the parameters tend to a certain limit (such as high signal-to-noise ratio, infinite number of antennas, and extremely large number of users). The Asymptotic (asymptotic) here verifies the performance of the analysis system in the high signal-to-noise ratio area by using the asymptotic expression of the high signal-to-noise ratio area through computer simulation. Through analysis, it can be seen that the interruption probability increases with the transmission power P of the main station PS. s The reliability decreases with the increase of , and gradually increases, and finally approaches a constant in the high signal-to-noise ratio region; and the increase in the number of STAR-RIS elements has a positive impact on the reliability of the STAR-RIS-assisted CR-NOMA network.

[0208] In one embodiment, a STAR-RIS assisted CR-NOMA network is provided, wherein the STAR-RIS assisted CR-NOMA network includes a primary station PS, a secondary station SS, a STAR-RIS equipped with 2L elements, M secondary users SU and a primary user PU, wherein the M secondary users SU include secondary users SU1 to SU2 located at the front side of the STAR-RIS. N , and the secondary user SU located at the rear of STAR-RIS N+1 ~Sub-user SU M , the primary station PS, the secondary station SS, STAR-RIS, M secondary users SU and the primary user PU together constitute a network architecture that can realize CR-NOMA network communication. In the STAR-RIS assisted CR-NOMA network, the secondary station SS receives the signal from the primary station PS, and the secondary station SS sends the same superimposed signal to the primary user PU and each secondary user SU through the broadcast feature; the STAR-RIS assisted CR-NOMA network is based on the interruption performance analysis method of the STAR-RIS assisted CR-NOMA network of any one of claims 1-8.

[0209] Simulation results show that the STAR-RIS-assisted CR-NOMA network can achieve full spatial coverage, flexible deployment and low-cost expansion, significantly reduce energy consumption and improve the reliability of the network system.

[0210] It should be noted that, unless otherwise defined, all terms used in this document have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs, and those terms defined in common dictionaries herein should be interpreted as having meanings consistent with their meanings in the context of the relevant technology. It should also be understood that the above is an illustration of the present disclosure and should not be considered as a limitation thereof. Although several exemplary embodiments of the present disclosure have been described, it will be readily understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and therefore, all such modifications are intended to be included within the scope of the present disclosure as defined in the claims and will not be described in detail herein.

Claims

1. A method for analyzing the outage performance of a STAR-RIS-assisted CR-NOMA network, characterized in that: include: A STAR-RIS-assisted overlay CR-NOMA network communication model is constructed, which includes a primary station PS, a secondary station SS, a STAR-RIS equipped with 2L elements, M secondary users SU and a primary user PU, wherein the M secondary users SU include secondary users SU1 to SU2 located in front of the STAR-RIS. N , and the secondary user SU located at the back side of the STAR-RIS N+1 ~Sub-user SU M The primary station PS, secondary station SS, STAR-RIS, M secondary users SU and primary user PU together constitute a network architecture capable of realizing CR-NOMA network communication. In this network communication model, the secondary station SS receives a signal from the primary station PS, and the secondary station SS sends the same superimposed signal to the primary user PU and each of the secondary users SU through the broadcast feature; Solving the received signal signal to noise ratio includes solving the message x of the primary user PU decoded at the secondary station SS. p The signal to interference noise ratio of the primary user PU decodes the message x p Signal to Interference and Noise Ratio; Secondary User SU m (N+1≤m≤M) decode the message x p , secondary user SU m Decoding secondary users News (m≤j1≤M) and secondary user SU m The signal to interference and noise ratio of decoding its own message; secondary user SU n (1≤n≤N) decode the message x p Signal to Interference and Noise Ratio, secondary user SU n Decoding secondary users information and secondary user SU n Signal-to-interference-and-noise ratio for decoding its own message; Derive the analytical expression of the interruption probability and calculate the interruption probability, including the interruption probability of the primary user PU, the secondary user SU m The interruption probability of the secondary user SU m The probability of interruption.

2. The interruption performance analysis method of the STAR-RIS assisted CR-NOMA network according to claim 1 is characterized in that: Also includes: Determine the asymptotic expression of the high signal-to-noise ratio area, perform asymptotic analysis on the high signal-to-noise ratio area, including performing asymptotic analysis on the high signal-to-noise ratio area of ​​the primary user PU, performing asymptotic analysis on the high signal-to-noise ratio area of ​​the secondary user SU m Asymptotic analysis is performed on the high signal-to-noise ratio region of the secondary user SU n Asymptotic analysis is performed in the high signal-to-noise ratio region.

3. The interruption performance analysis method of the STAR-RIS assisted CR-NOMA network according to claim 2, characterized in that: The method also includes: analyzing the user's diversity order, including analyzing the diversity order of the primary user PU, the secondary user SU m The order of diversity, the secondary users The diversity order of the secondary user SU n The diversity order of the, the diversity order of the and the sub-users order of diversity.

4. The method for analyzing the interruption performance of a STAR-RIS-assisted CR-NOMA network according to claim 3, characterized in that: The signal received by the secondary station SS from the primary station PS is represented as: Among them, h ss It is represented as the link channel from the primary station PS to the secondary station SS, P s is the transmission power of the primary station PS, x p is the normalized information of the primary user PU, and E(|x p | 2 )=1,d ss and α ss is the distance and path loss index of the link channel from the primary station PS to the secondary station SS, n1 is complex additive Gaussian white noise; When the secondary station SS sends the same superposition signal to the primary user PU and the secondary user SU through the broadcast feature, the secondary user SU located in front of the STAR-RIS n (1≤n≤N) The signal received from the secondary station SS and the signal reflected by the STAR-RIS are: Among them, h sn It is represented as from the secondary station SS to the secondary user SU n Link channel, h sr Denote the link channel from the secondary station SS to the STAR-RIS, h rn It is represented as from the STAR-RIS to the secondary user SU n Link channel, d sn , d sr , d rn and α st , α sr , α rn Represents SS-SU respectively n link, SS-STAR-RIS link, and STAR-RIS-SU n The distance and path loss exponent of the link; x p represents the message of the primary user PU; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; x s,i and b i Denotes the message and power allocation parameters of the ith user, subject to b1<...b n <...b N N+1 <...b m M ; n2 is the complex white Gaussian noise, is the reflection phase shift matrix of STAR-RIS, and represent the amplitude and phase shift of the lth element of STAR-RIS respectively;​​ The secondary user SU m The signal received from the STAR-RIS is represented by: Among them, h sr Denote the link channel from the secondary station SS to the STAR-RIS, h rm It is represented as from the STAR-RIS to the secondary user SU m Link channel, d sr , d rm and α sr , α rm Respectively represent SS-STAR-RIS link and STAR-RIS-SU m The distance and path loss exponent of the link; x p represents the message of the primary user PU; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; x s,i and b i Denotes the message and power allocation parameters of the ith user, subject to b1<...b n <...b N N+1 <...b m M ; is the transmission phase shift matrix of STAR-RIS, and represents the amplitude and phase shift of the lth element of STAR-RIS; n3 is the complex additive Gaussian white noise with an average power of N0;​​ The signal received by the primary user PU is expressed as: Among them, h sr Denote the link channel from the secondary station SS to the STAR-RIS, h rp It is represented as the link channel from the STAR-RIS to the primary user PU; d sr , d rp and α sr , α rp Represent the distance and path loss index of SS-STAR-RIS link and STAR-RIS-PU link respectively; x p represents the message of the primary user PU; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; x s,i and b i Denotes the message and power allocation parameters of the ith user, subject to b1<...b n <...b N N+1 <...b m M ; is the transmission phase shift matrix of STAR-RIS, and represents the amplitude and phase shift of the first element of STAR-RIS; n4 is the complex additive Gaussian white noise with an average power of N0.​​ 5. The method for analyzing the interruption performance of a STAR-RIS-assisted CR-NOMA network according to claim 4, characterized in that: In the calculation of the signal-to-interference-and-noise ratio of the received signal, the decoding of the message x at the secondary station SS is calculated based on the signal received by the secondary station SS from the primary station PS. p The signal-to-interference-and-noise ratio is as follows: Among them, d ss and α ss is the distance and path loss index of the PS-SS link, P s is the transmission power of the primary station PS; N0 is the average power of the additive Gaussian white noise; Based on the signal received by the primary user PU, solve the message x decoded by the primary user PU p The signal-to-interference-and-noise ratio is as follows: Among them, h sr Denote the link channel from the secondary station SS to the STAR-RIS, h rp Denote the link channel from the STAR-RIS to the primary user PU, d sr , d rp and α sr , α rp P represents the distance and path loss index of SS-STAR-RIS link and STAR-RIS-PU link respectively; s is the transmission power of the primary station PS; a1, a2 represent the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; b i represents the power allocation parameter of the ith user, subject to b1<...b n <...b N N+1 <...b m M ; N0 is the average power of additive Gaussian white noise; is the transmission phase shift matrix of STAR-RIS, and represents the amplitude and phase shift of the lth element of STAR-RIS;​​ Based on the secondary user SU m The signal received from the STAR-RIS is used to solve the secondary user SU m Decode the message x of the primary user PU p , the secondary user News And the signal-to-interference-noise ratio of its own message is as follows: Among them, h sr Denote the link channel from the secondary station SS to the STAR-RIS, h rp Denote the link channel from the STAR-RIS to the primary user PU, h rm It is represented as from the STAR-RIS to the secondary user SU m Link channel, d sr , d rp , d rm and α sr , α rp , α rm Represents SS-STAR-RIS link, STAR-RIS-PU link and STAR-RIS-SU link respectively m Link distance and path loss index; P s is the transmission power of the primary station PS; a1, a2 represent the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; Φ T = is the transmission phase shift matrix of STAR-RIS, and represents the amplitude and phase shift of the lth element of STAR-RIS; represents the power allocation parameter of the j1th secondary user; b m represents the power allocation parameter of the mth user; N0 is the average power of the complex additive Gaussian white noise; b q represents the power allocation parameter of the qth secondary user; Based on the secondary user SU n (1≤n≤N) receives the signal from the secondary station SS and the signal reflected by the STAR-RIS, and solves the secondary user SU n Decode the primary user PU message x p , the secondary user information And the signal-to-interference-noise ratio of its own message is as follows: Among them, h sn It is represented as from the secondary station SS to the secondary user SU n Link channel, h sr Denote the link channel from the secondary station SS to the STAR-RIS, h rn It is represented as from the STAR-RIS to the secondary user SU n Link channel, d sn and α sn Represents SS-SU respectively n Link distance and path loss index; P s is the transmission power of the primary station PS; a1 and a2 represent the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; b1<...b n <...b N N+1 <...b m M ; is the reflection phase shift matrix of STAR-RIS, and are the amplitude and phase shift of the first element of STAR-RIS; b i represents the power allocation parameter of the ith user, subject to b1<...b n <...b N N+1 <...b m M ; N0 is the average power of additive Gaussian white noise; b q represents the power allocation parameter of the qth secondary user.​​​​ 6. The method for analyzing the interruption performance of a STAR-RIS-assisted CR-NOMA network according to claim 5, characterized in that: Based on decoding the message x at the secondary station SS p The signal to interference noise ratio and the primary user PU decoding the message x p The interruption probability of the primary user PU is derived from the signal to interference noise ratio, and in the derivation of the interruption probability of the primary user PU, the interruption probability of the primary user PU is obtained only when the secondary station SS and the primary user PU both successfully decode the message x p When , the primary user PU will not be in an interrupted state. The specific derivation formula is as follows: in, and m ss represents the Nakagami-m fading severity parameter, where m is the mth secondary user number; To detect message x p The target SNR is: N0 is the average power of the additive Gaussian white noise; Ω ss Expressed as the average power of Nakagami-m; d ss and α ss P is the distance and path loss index of the link channel from the primary station PS to the secondary station SS; p is the transmission power of the secondary station SS; d sr , d rp and α sr , α rp denote the distance and path loss index of the SS-STAR-RIS link and the STAR-RIS-PU link respectively; a1, a2 denote the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1≥a2, a1+a2=1; P s is the transmission power of the primary station PS; Γ is represented by the gamma function; K p and θ p They represent the shape parameter and scale parameter of the SS-RIS-PU composite link after it is approximated to the Gamma distribution; Based on decoding the message x at the secondary station SS p The signal to interference and noise ratio, and the secondary user SU m Decode the message x of the primary user PU p , the secondary user News and the signal to interference noise ratio of its own message to derive the secondary user SU m The interruption probability of the secondary user SU is derived m The interruption probability of the secondary user SU is only when the following conditions are met. m The secondary station SS can successfully decode the message x p ; 2) the secondary user SU m Successfully decode the message x of the primary user PU p ; 3) the secondary user SU m Successfully decoded the secondary user News 4) The secondary user SU m Successfully decoded its own message; details are as follows: in, and d sr , d rm and α sr , α rm Respectively represent SS-STAR-RIS link and STAR-RIS-SU m Link distance and path loss index; P s is the transmission power of the primary station PS; Γ represents the gamma function; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; To detect message x p Target SNR; To detect messages The target SNR is: N0 is the average power of the additive Gaussian white noise; K x and θ x Represents SS-RIS-SU respectively m The shape and scale parameters of the composite link are approximated to the Gamma distribution; Based on decoding the message x at the secondary station SS p The signal to interference and noise ratio, and the secondary user SU n Decode the primary user PU message x p , the secondary user information and the signal to interference noise ratio of its own message to derive the secondary user SU n The interruption probability of the secondary user SU is derived n When the interruption probability is less than 0, the following conditions need to be met: 1) The secondary station SS can successfully decode the message x of the primary user PU p ; 2) SU n Successfully decoded message x p ; 3) the secondary user SU n Successfully decoded the secondary user News 4) The secondary user SU n Successfully decoded its own message; details are as follows: in, φ n 、 are all expressed as a mathematical operation, expressed as γ represents the lower half of the incomplete gamma function; h sr Denote the link channel from the secondary station SS to the STAR-RIS, h rn It is represented as from the STAR-RIS to the secondary user SU n Link channel; m sr Expressed as the Nakagami-m fade severity parameter from the secondary station SS to STAR-RIS; m rn From STAR-RIS to secondary user SU n Nakagami-m fading severity parameter; d sn and α sn Represents SS-SU respectively n Link distance and path loss index; P s is the transmission power of the primary station PS; Γ represents the gamma function; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; To detect message x p Target SNR; To detect messages The target SNR is: N0 is the average power of the additive Gaussian white noise; K1 is the index of the variable in the finite summation, ranging from 0<<K1<<m ss -1;m ss represents the Nakagami-m fade severity parameter; represents the power allocation parameter of the j2th secondary user; b i represents the power allocation parameter of the ith user, subject to b1<...b n <...b N N+1 <...b m M .​​ 7. The method for analyzing the interruption performance of a STAR-RIS-assisted CR-NOMA network according to claim 6, characterized in that: In the asymptotic analysis of the high signal-to-noise ratio region, based on the derived interruption probability of the primary user PU, the analysis is performed by determining an asymptotic expression for the high signal-to-noise ratio region. The asymptotic expression for the high signal-to-noise ratio region of the primary user PU is specifically as follows: in, d sr , d rp and α sr , α rp denote the distance and path loss index of the SS-STAR-RIS link and the STAR-RIS-PU link, respectively; a1 and a2 denote the power allocation parameters of the primary user PU message and the secondary user message, satisfying a1 ≥ a2, a1 + a2 = 1; To detect message x p Target SNR; K p and θ p They represent the shape parameter and scale parameter of the SS-RIS-PU composite link after it is approximated to the Gamma distribution; Based on the derived secondary user SU m The interruption probability of the secondary user SU m The asymptotic expression of the high signal-to-noise ratio region is as follows: in, and d sr , d rm and α sr , α rm Respectively represent SS-STAR-RIS link and STAR-RIS-SU m Link distance and path loss index; a1, a2 represent the power allocation parameters for messages from the primary user PU and the secondary user, satisfying a1≥a2, a1+a2=1; To detect message x p Target SNR; K x and θ x Represents SS-RIS-SU respectively m The shape and scale parameters of the composite link are approximated to the Gamma distribution; Based on the derived secondary user SU n The interruption probability of the secondary user SU n The asymptotic expression of the high signal-to-noise ratio region is as follows: in, m ss represents the Nakagami-m fading severity parameter, where m is the mth secondary user number; γ represents the lower half of the incomplete gamma function; k1; d sn and α sn Represents SS-SU respectively n Link distance and path loss index; P s is the transmission power of the primary station PS; a1, a2 represent the power allocation parameters of the message of the primary user PU and the message of the secondary user, satisfying a1≥a2, a1+a2=1; To detect message x p Target SNR; b i represents the power allocation parameter of the ith user, subject to b1<...b n <...b N N+1 <...b m M ; To detect messages Target SNR; represents the power allocation parameter of the j2th secondary user.​​ 8. The method for analyzing the interruption performance of a STAR-RIS-assisted CR-NOMA network according to claim 7, characterized in that: In analyzing the diversity order of users, the diversity order of users is first analyzed by defining an equation as follows: in, P s is the transmission power of the primary station PS; N0 is the average power of the additive white Gaussian noise; Shown is the asymptotic expression for the high signal-to-noise ratio region; Then the diversity order of the primary user PU is analyzed, and the secondary user SU m The diversity order of the secondary users The diversity order of the secondary user SU n The order of diversity and the secondary users The diversity order of is expressed as follows: Among them, d PU It is represented as the diversity order of the primary user PU, Denoted as the secondary user SU m The order of diversity, Denoted as the secondary user SU n The order of diversity, Denoted as the secondary user SU j2 order of diversity.

9. A STAR-RIS assisted CR-NOMA network, characterized in that: The STAR-RIS assisted CR-NOMA network includes a primary station PS, a secondary station SS, a STAR-RIS equipped with 2L elements, M secondary users SU and a primary user PU, wherein the M secondary users SU include secondary users SU1 to SU2 located at the front side of the STAR-RIS. N , and the secondary user SU located at the back side of the STAR-RIS N+1 ~Sub-user SU M The primary station PS, secondary station SS, STAR-RIS, M secondary users SU and primary user PU together constitute a network architecture capable of realizing CR-NOMA network communication. In the STAR-RIS assisted CR-NOMA network, the secondary station SS receives a signal from the primary station PS, and the secondary station SS sends the same superimposed signal to the primary user PU and each of the secondary users SU through the broadcast characteristics; the STAR-RIS assisted CR-NOMA network is deployed based on the analysis method for the interruption performance analysis of the STAR-RIS assisted CR-NOMA network according to any one of claims 1 to 8.

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