Spectrum sensing method, system, storage medium and non-stationary transmission user end

Abstract

The application provides a spectrum sensing method, system, storage medium and non-fixed transmission user terminal, which is applied to the non-fixed transmission user terminal and comprises the following steps: obtaining sensing signals of non-fixed transmission users with higher priority than the non-fixed transmission user on a target frequency band; calculating characteristic peak values of the non-fixed transmission user based on the sensing signals; when the characteristic peak value is less than a detection threshold, determining that the target frequency band is not occupied by the non-fixed transmission users with higher priority than the non-fixed transmission user, and the non-fixed transmission user has the right to use the target frequency band simultaneously with fixed transmission users; otherwise, determining that the target frequency band has been occupied, and the non-fixed transmission user does not have the right to use the target frequency band simultaneously with the fixed transmission users. The spectrum sensing method, system, storage medium and non-fixed transmission user terminal can increase the number of identifiable and perceptible users without affecting the detection performance of the users, and effectively improve the spectrum efficiency of the uplink non-orthogonal transmission system.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a spectrum sensing method, system, storage medium, and non-fixed transmission user terminal. Background Technology

[0002] In recent years, with the development of wireless communication technology and the popularization of smart terminals, the demand for data communication from mobile users has increased significantly, putting enormous pressure on limited spectrum resources. To utilize spectrum resources more effectively, cognitive radio (CR) technology has received widespread attention from academia and industry. A CR network consists of primary users and cognitive users. Cognitive users can identify unused frequency bands by using spectrum sensing technology and utilize these spectrum resources for temporary data transmission. Therefore, in a CR network, the accuracy of spectrum sensing by cognitive users is a major factor affecting its performance.

[0003] Existing technologies include many techniques for identifying and detecting primary users, which mainly fall into the following two categories:

[0004] (1) Energy detection category

[0005] The basic principle of energy detection technology is to use signal energy as an indicator that the primary user is transmitting. Given a specific energy threshold, the cognitive user periodically monitors the signal energy in the target frequency band; if the current signal energy in the target frequency band is higher than the given threshold, it is determined that the primary user is transmitting; otherwise, it is determined that the primary user is not transmitting.

[0006] (2) Feature Detection

[0007] The basic principle of feature detection technology is to assign specific feature tags to the main user in advance, and recognize that the user periodically monitors the signal characteristics on the target frequency band; if the current signal characteristics of the target frequency band meet the requirements, it is determined that the main user is transmitting; otherwise, it is determined that the main user is not transmitting.

[0008] Meanwhile, existing cellular communication systems primarily use orthogonal multiple access (OMA) technology. However, with the rapid increase in the number of user terminals, existing OMA methods are gradually failing to meet the spectral efficiency and large-scale access requirements of future cellular networks. Non-orthogonal multiple access (NOMA) technology improves system capacity by multiplexing time-frequency resources and uses receiver techniques at the receiving end to separate data from different users. With the continuous development of NOMA technology research, various methods for non-orthogonal data transmission have emerged. One method involves multiplexing user signals in the power domain to achieve multiple access. At the transmitting end, signals from different users are superimposed in the power domain, and at the receiving end, serial interference cancellation techniques are used to sequentially separate the signals from each user. Summary of the Invention

[0009] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a spectrum sensing method, system, storage medium, and non-fixed transmission user terminal, which can increase the number of identifiable and sensing users without affecting the user's detection performance, and effectively improve the spectrum efficiency of the uplink non-orthogonal transmission system.

[0010] To achieve the above and other related objectives, this invention provides a spectrum sensing method for uplink non-orthogonal transmission, applied to a non-fixed transmission user terminal, comprising the following steps: acquiring sensing signals of non-fixed transmission users with higher priority on a target frequency band; calculating characteristic peak values ​​of the non-fixed transmission users based on the sensing signals; when the characteristic peak value is less than a detection threshold, determining that the target frequency band is not occupied by a non-fixed transmission user with higher priority, and having the right to use the target frequency band simultaneously with a fixed transmission user; otherwise, determining that the target frequency band has been occupied, and having no right to use the target frequency band simultaneously with the fixed transmission user.

[0011] In one embodiment of the present invention, calculating the characteristic peak value of the non-fixed transmission user based on the sensing signal includes the following steps:

[0012] The sensing signal is cyclically shifted and conjugate processed, where the number of cyclic shifts is a characteristic value of the non-fixed transmission user.

[0013] An autocorrelation operation is performed on the sensed signal and the conjugate signal after cyclic shifting to obtain the autocorrelation value;

[0014] The autocorrelation value is used as the characteristic peak value.

[0015] In one embodiment of the present invention, the feature values ​​of the non-fixed transmission users are recorded in a feature value table for non-fixed transmission users; the feature values ​​are fixed values ​​preset by humans or dynamic values ​​that change according to predetermined rules.

[0016] In one embodiment of the present invention, the feature values ​​of different non-fixed transmission users at the same time must be different, while the feature values ​​of different non-fixed transmission users at different times can be the same.

[0017] In one embodiment of the present invention, the detection threshold is determined based on the false alarm probability; the false alarm probability refers to the probability that the characteristic peak formed by the sum of noise and the signal of the fixed transmission user on the target frequency band is greater than a preset threshold.

[0018] In one embodiment of the present invention, the detection thresholds used for different non-fixed transmission users with higher priorities than themselves may be the same or different.

[0019] In one embodiment of the present invention, when the non-fixed transmission user and the fixed transmission user use the target frequency band simultaneously, an uplink non-orthogonal merging transmission method is adopted.

[0020] This invention provides a spectrum sensing system for uplink non-orthogonal transmission, applied to non-fixed transmission user terminals, including a signal acquisition module, a calculation module, and a judgment module;

[0021] The signal acquisition module is used to acquire the sensing signals of non-fixed transmission users with higher priority than itself on the target frequency band;

[0022] The calculation module is used to calculate the characteristic peak values ​​of the non-fixed transmission user based on the sensing signal;

[0023] The judgment module is used to determine that when the feature peak value is less than the detection threshold, the target frequency band is not occupied by a non-fixed transmission user with a higher priority, and the user has the right to use the target frequency band at the same time as a fixed transmission user; otherwise, it determines that the target frequency band has been occupied, and the user does not have the right to use the target frequency band at the same time as the fixed transmission user.

[0024] The present invention provides a storage medium storing a computer program thereon, which, when executed by a processor, implements the above-described spectrum sensing method for uplink non-orthogonal transmission.

[0025] This invention provides a non-fixed transmission user terminal, comprising: a processor and a memory;

[0026] The memory is used to store computer programs;

[0027] The processor is used to execute the computer program stored in the memory to enable the non-fixed transmission user terminal to perform the above-described uplink non-orthogonal transmission spectrum sensing method.

[0028] As described above, the spectrum sensing method, system, storage medium, and non-fixed transmission user terminal of the present invention have the following beneficial effects:

[0029] (1) It can provide sensing users in uplink non-orthogonal transmission systems with a strategy to sense the transmission status of high-priority users and appropriately occupy the spectrum, so as to utilize the originally idle spectrum without affecting the data transmission of high-priority users as much as possible.

[0030] (2) Significantly improved sensing accuracy and significantly improved spectrum efficiency by jointly sensing the spectrum of multiple users;

[0031] (3) Enable more users to participate in spectrum sensing and allocation in the same frequency band, and enable related spectrum sensing applications to match the next generation of mobile communication systems;

[0032] (4) It is easy to implement, requires no modification to the existing system's hardware structure, and is convenient for practical promotion and application. Attached Figure Description

[0033] Figure 1 The flowchart shown is a representation of one embodiment of the spectrum sensing method for uplink non-orthogonal transmission of the present invention;

[0034] Figure 2 The diagram shows a framework schematic of the uplink non-orthogonal transmission spectrum sensing method of the present invention in one embodiment;

[0035] Figure 3 The flowchart shown illustrates a user-sent signal in one embodiment of the present invention.

[0036] Figure 4 The diagram shown is a structural schematic of the uplink non-orthogonal transmission spectrum sensing system of the present invention in one embodiment.

[0037] Figure 5 The diagram shown is a structural schematic of a non-fixed transmission user terminal according to one embodiment of the present invention.

[0038] Component designation explanation

[0039] 41 Signal Acquisition Module

[0040] 42 Calculation Module

[0041] 43 Judgment Module

[0042] 51 processor

[0043] 52 Memory Detailed Implementation

[0044] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0045] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0046] The spectrum sensing method, system, storage medium, and non-fixed transmission user terminal of the present invention can provide low-priority non-fixed transmission users in uplink non-orthogonal transmission systems with a strategy to sense the transmission status of high-priority non-fixed transmission users and appropriately occupy the spectrum. While minimizing impact on the data transmission of high-priority non-fixed transmission users, it utilizes previously idle spectrum, thereby increasing the number of identifiable and senseable users without affecting user detection performance. This effectively improves the spectrum efficiency of uplink non-orthogonal transmission systems and is highly practical.

[0047] like Figure 1 and Figure 2 As shown, in one embodiment, the spectrum sensing method for uplink non-orthogonal transmission of the present invention includes the following steps:

[0048] Step S1: Obtain the sensing signals of non-fixed transmission users with higher priority than itself on the target frequency band.

[0049] Specifically, in an uplink non-orthogonal transmission system, multiple users act as transmitters. Some users are fixed to transmit information and are called fixed transmission users; others are qualified to transmit and are called non-fixed transmission users. Non-fixed transmission users can choose when to transmit information according to their needs and merge their transmissions with those of the fixed transmission users in an uplink non-orthogonal manner. Each non-fixed transmission user has a different priority. For a non-fixed transmission user with priority k, if it wants to occupy a target frequency band to transmit information, it needs to sequentially detect the signal transmission status of k-1 non-fixed transmission users with priorities 1, 2…(k-1) on the target frequency band. If none of the first k-1 non-fixed transmission users are currently transmitting signals on the target frequency band, then the k-th non-fixed transmission user can share the target frequency band with the fixed users for signal transmission. Therefore, it is necessary to first obtain the sensing signals of non-fixed transmission users with higher priorities on the target frequency band.

[0050] The system has M non-fixed transmission users and N fixed transmission users. k∈[1,M], i∈[1,k-1], j∈[M+1,M+N]. Before transmitting, the non-fixed transmission user (sensing subject) with priority k needs to detect the transmission status of the non-fixed transmission user with priority i (i∈[1,k-1]). Let the original signal of the non-fixed transmission user with priority i be x. i The transmission power is α i , where ∑ i α i +∑ j α j =1 and α i a j >0. Without loss of generality, such as Figure 3 As shown, each non-fixed transmission user uses two transmitting antennas to transmit signals. The signals are encoded and modulated, and then emitted from antenna 1 in a non-orthogonal form. The signal is then cyclically shifted by a distance d. i And it is emitted from antenna 2. Taking user i as an example, i.e., t i1 (n)=α i x i (n) and t i2 (n)=α i x i (n+d i The channel coefficient between antenna 1 of user i and sensing user k is h. ik1 The channel coefficient between antenna 2 and sensing user k is h. ik2 Then the perceived signal received by user k is the sum of the dual-antenna signals of all other users through their corresponding channels, plus the noise signal, i.e., r. ik (n)=h ik ti (n)+∑ j h jk t j (n)+w ik (n), where h ik and t i (n) represent the channel coefficients from the dual antennas of the i-th priority non-fixed transmission user to the k-th priority non-fixed transmission user (sensing subject) and the transmit signal matrix of the i-th priority non-fixed transmission user, respectively, i.e., h ik =[h ik1 h ik2 ], t i (n)=[t i1 , t i2 ] T h jk =[h jk1 h jk2 ] and t j (n) represent the channel coefficients from the dual antennas of the j-th fixed transmission user to the k-th non-fixed transmission user (sensing subject) and the transmitted signal matrix of the j-th non-fixed transmission user, respectively; w ik (n) is additive white Gaussian noise (AWGN) with a specific power.

[0051] Step S2: Calculate the characteristic peak value of the non-fixed transmission user based on the sensing signal.

[0052] Specifically, the present invention employs cyclic delay diversity (CDD) technology to utilize the diversity gain of multiple antennas to obtain the characteristic peak values ​​of non-fixed transmission users.

[0053] In one embodiment of the present invention, calculating the characteristic peak value of the non-fixed transmission user based on the sensing signal includes the following steps:

[0054] 21) The sensing signal is cyclically shifted and conjugate processed, wherein the number of cyclic shifts is the characteristic value of the non-fixed transmission user.

[0055] Among them, the non-fixed transmission user with priority k performs a cyclic shift and conjugate processing on the sensing signal, that is, the sensing signal r ik Circularly shift δ data points and conjugate them to obtain r. ik *(n+δ). Where δ is the number of cyclic shifts, and is the characteristic value of the non-fixed transmission user sending the sensing signal. In this invention, each non-fixed transmission user maintains its own characteristic value table; the characteristic values ​​in the characteristic value table are used to mark and distinguish the signals sent by different non-fixed transmission users. The characteristic values ​​are obtained in any of the following ways: (1) fixed values ​​preset by humans; (2) dynamic values ​​that change according to predetermined rules. It should be noted that the characteristic values ​​of different non-fixed transmission users must be different at the same time, while the characteristic values ​​of different non-fixed transmission users can be the same at different times.

[0056] 22) Perform an autocorrelation operation on the sensed signal and the conjugate signal after cyclic shift to obtain an autocorrelation value; use the autocorrelation value as the characteristic peak value.

[0057] Specifically, regarding the sensing signal r ik and the conjugate signal r after cyclic shift ik * Autocorrelation is performed on (n+δ) to obtain an accumulated and averaged autocorrelation value. Among them, S ik This is the length of the sensed signal. Since the autocorrelation value reaches a maximum peak when the number of cyclic shifts is the characteristic value, therefore R... ik (δ) represents the characteristic peak value of the non-fixed transmission user with priority i.

[0058] Step S3: When the characteristic peak value is less than the detection threshold, it is determined that the target frequency band is not occupied by a non-fixed transmission user with a higher priority, and the user has the right to use the target frequency band at the same time as a fixed transmission user; otherwise, it is determined that the target frequency band has been occupied, and the user has no right to use the target frequency band at the same time as the fixed transmission user.

[0059] Specifically, determining whether the target frequency band is occupied by a non-fixed transmission user with a higher priority is a binary decision process. The state where, at the time of perception, there is actually no characteristic peak corresponding to a non-fixed transmission user with priority i on the target frequency band is defined as H. ik0 The state of the characteristic peak corresponding to the non-fixed transmission user with priority k at the time of perception and the actual existence of the non-fixed transmission user with priority i in the target frequency band is H. ik1 Then the sensing signal acquired in the target frequency band can be expressed as Therefore, the decision-making criterion is Where λ ik It is the threshold for determining the characteristic peak of a non-fixed transmission user with priority k for a non-fixed transmission user with priority i on the target frequency band, i.e., the detection threshold. and The results correspond to the state judgment results of non-fixed transmission users with priority k, determining whether the target frequency band contains or does not contain the characteristic peak corresponding to non-fixed transmission users with priority i.

[0060] The detection threshold of this invention is often limited by the false alarm probability. The false alarm probability (Pf) refers to the probability that the characteristic peak value formed by noise on the target frequency band exceeds a preset threshold; that is, the probability that the sensing user mistakenly judges that the target user is occupying the target frequency band resources when the target user is not actually occupying them. Since this invention is designed for uplink non-orthogonal transmission systems, the non-orthogonal signals of users typically have their own transmission states, some fixed and some non-fixed. Therefore, the false alarm probability is equivalent to the probability that the characteristic peak value formed by the sum of noise and signals from fixed-transmission users at the target sensing location exceeds a preset threshold, which can be expressed mathematically as follows: Therefore, the detection threshold λ can be obtained by reverse calculation using the above expression based on the false alarm probability value defined in the actual scenario. ik In one embodiment of the present invention, the detection thresholds used for different non-fixed transmission users with higher priorities than themselves may be the same or different.

[0061] When the feature peak value of all non-fixed transmission users i (i∈[1, k-1]) with higher priority than itself is less than the detection threshold, the non-fixed transmission user with priority k determines that all non-fixed transmission users i with higher priority are not currently occupying the target frequency band resources. Therefore, it has the right to use the target frequency band simultaneously with the fixed transmission user and can send information to the corresponding target user terminal based on whether it has a transmission requirement. Otherwise, it determines that the target frequency band is occupied and has no right to use the target frequency band simultaneously with the fixed transmission user. In one embodiment of the present invention, when the non-fixed transmission user and the fixed transmission user use the target frequency band simultaneously, an uplink non-orthogonal merging transmission method is adopted.

[0062] The spectrum sensing method for uplink non-orthogonal transmission of the present invention will be further illustrated below through specific embodiments.

[0063] In this embodiment, in the uplink non-orthogonal scenario, a feature detection-based spectrum sensing technology is used as the basis for decision-making, and the differences in the sensing results of multiple antennas at the receiving end are used as the basis. Assume the system has M non-fixed transmission users, N fixed transmission users, and one base station. Without loss of generality, consider a system where M=2 and N=1, i.e., user 3 is fixed in transmitting information, user 1's transmission status is not fixed, and user 2's transmission status is sensed based on this.

[0064] Each transmitting user is configured with two antennas, using Non-Orthogonal Multiple Access (NOMA) technology to transmit signals, and using Cyclic Delay Diversity (CDD) technology to embed the user's characteristic value δ into the transmitted NOMA signal stream. User 1 transmits signal t on the first antenna. 11 (n), and on the second antenna, t 11 (n) After cyclic shift δ, the signal is transmitted, i.e., the transmitted signal t on the second antenna. 12 (n)=t 11 (n+δ), where the cyclic shift δ is the user's unique feature.

[0065] The specific steps are as follows:

[0066] 1) First, generate the NOMA signal. Consider two users in a non-orthogonal transmission system using Low-Dity Parity-Check (LDPC) coding and Quadrature Phase Shift Keying (QPSK) modulation. Each data block is 4096 bits long. Taking user 1 as an example, the data transmitted by the first antenna is t. 11 (n) = α1x1(n), and the data transmitted by the second antenna is t. 12 (n) = α1x1(n+d1).

[0067] 2) User 2 receives the signals from User 1 and User 3 after passing through the Rayleigh channel, along with noise. The signal expression is r. 12 (n)=h 12 t1(n)+h 32 t3(n)+w 12 (n), where h 12 =[h 121 h 122 ], h 32 =[h 321 h 322 ], t1(n)=[t 11 (n), t 12 (n)] T t3(n)=[t 31 (n), t 32 (n)] T w(n) is additive white Gaussian noise with a specific power. 121 and h 122 These are the channel parameters between User 1's two antennas and User 2, and the signal-to-noise ratio difference between them is fixed. The same applies to User 3.

[0068] 3) After collecting r(n) for user 2, perform an autocorrelation operation with its own cyclically shifted signal r(n+δ) to obtain the feature placement R for each user. The autocorrelation operation includes, but is not limited to, the following methods: Where S 12 It is the length of the received signal.

[0069] 4) Each receiving antenna will calculate its own characteristic peak value |R 12 The detection threshold λ is compared with a pre-defined detection threshold λ. The false alarm probability is fixed, and the detection threshold λ is calculated based on the distribution of the noise using the distribution principle and the law of large numbers. The comparison methods include, but are not limited to: if |R| 12 |<λ 12 If the antenna determines that user 1 is not transmitting, then if |R 12 |>λ 12 If so, the antenna determines that user 1 is currently transmitting.

[0070] 5) If user 2 detects that user 1 is not transmitting, then user 2 will transmit information in NOMA form together with N users who are transmitting in a fixed manner; otherwise, user 2 will not send information.

[0071] like Figure 4 As shown, in one embodiment, the uplink non-orthogonal transmission spectrum sensing system of the present invention includes a signal acquisition module 41, a calculation module 42, and a judgment module 43.

[0072] The signal acquisition module 41 is used to acquire the perception signal of a non-fixed transmission user with a higher priority than itself on the target frequency band.

[0073] The calculation module 42 is connected to the signal acquisition module 41 and is used to calculate the characteristic peak value of the non-fixed transmission user based on the sensing signal.

[0074] The judgment module 43 is connected to the calculation module 42 and is used to determine that when the feature peak value is less than the detection threshold, the target frequency band is not occupied by a non-fixed transmission user with a higher priority and has the right to use the target frequency band at the same time as a fixed transmission user; otherwise, it is determined that the target frequency band has been occupied and has no right to use the target frequency band at the same time as the fixed transmission user.

[0075] The structure and principle of the signal acquisition module 41, the calculation module 42 and the judgment module 43 correspond one-to-one with the steps in the above-mentioned uplink non-orthogonal transmission spectrum sensing method, so they will not be described again here.

[0076] It should be noted that the division of the various modules in the above device is merely a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. Furthermore, these modules can be implemented entirely in software via processing element calls, entirely in hardware, or partially in software calls via processing elements and partially in hardware. For example, module x can be a separate processing element or integrated into a chip within the device. Additionally, module x can be stored as program code in the device's memory, invoked and executed by a processing element. The implementation of other modules is similar. These modules can be fully or partially integrated together or implemented independently. The processing element mentioned here can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each of the above modules can be completed through integrated logic circuits in the hardware of the processor element or through software instructions. These modules can be one or more integrated circuits configured to implement the above methods, such as one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Field Programmable Gate Arrays (FPGAs), etc. When a module is implemented through processing element scheduler code, the processing element can be a general-purpose processor, such as a Central Processing Unit (CPU) or other processor capable of calling program code. These modules can be integrated together to implement a System-on-a-Chip (SOC).

[0077] The storage medium of the present invention stores a computer program, which, when executed by a processor, implements the aforementioned spectrum sensing method for uplink non-orthogonal transmission. Preferably, the storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disk, USB flash drive, memory card, or optical disk.

[0078] like Figure 5 As shown, in one embodiment, the non-fixed transmission user terminal of the present invention includes a processor 51 and a memory 52.

[0079] The memory 52 is used to store computer programs. The memory 52 includes various media capable of storing program code, such as ROM, RAM, magnetic disk, USB flash drive, memory card, or optical disk.

[0080] The processor 51 is connected to the memory 52 and is used to execute the computer program stored in the memory so that the non-fixed transmission user terminal performs the above-described uplink non-orthogonal transmission spectrum sensing method.

[0081] Preferably, the processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0082] In summary, the spectrum sensing method, system, storage medium, and non-fixed transmission user terminal of the present invention can provide sensing users in uplink non-orthogonal transmission systems with a strategy to sense the transmission status of high-priority users and appropriately occupy the spectrum. This utilizes previously idle spectrum while minimizing impact on high-priority users' data transmission. It significantly improves sensing accuracy and, by jointly sensing the spectrum of multiple non-fixed transmission users, significantly improves spectrum efficiency. It supports more users participating in spectrum sensing and allocation within the same frequency band and enables related spectrum sensing applications to be compatible with next-generation mobile communication systems. It is easy to implement, requiring no modification to the existing system's hardware structure, and is convenient for practical promotion and application. Therefore, the present invention effectively overcomes the various shortcomings of the prior art and has high industrial applicability.

[0083] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A spectrum sensing method for uplink non-orthogonal transmission, applied to non-fixed transmission user terminals, characterized in that: Includes the following steps: Acquire the sensed signals of non-fixed transmission users with higher priority than itself on the target frequency band; Calculate the characteristic peak values ​​of the non-fixed transmission user based on the sensed signal; When the characteristic peak value is less than the detection threshold, it is determined that the target frequency band is not occupied by a non-fixed transmission user with a higher priority, and the user has the right to use the target frequency band simultaneously with a fixed transmission user; otherwise, it is determined that the target frequency band has been occupied, and the user does not have the right to use the target frequency band simultaneously with the fixed transmission user. The non-fixed transmission user is a user who is qualified to transmit information and can select the information to be transmitted according to their own needs, and is merged with the fixed transmission user in an uplink non-orthogonal form for transmission; the fixed transmission user is a user who transmits fixed information. Calculating the characteristic peak values ​​of the non-fixed transmission user based on the sensed signal includes the following steps: The sensing signal is cyclically shifted and conjugate processed, where the number of cyclic shifts is a characteristic value of the non-fixed transmission user. An autocorrelation operation is performed on the sensed signal and the conjugate signal after cyclic shifting to obtain the autocorrelation value; The autocorrelation value is used as the characteristic peak value.

2. The spectrum sensing method for uplink non-orthogonal transmission according to claim 1, characterized in that: The characteristic values ​​of the non-fixed transmission users are recorded in the characteristic value table of non-fixed transmission users; The feature value is either a fixed value preset by humans or a dynamic value that changes according to predetermined rules.

3. The spectrum sensing method for uplink non-orthogonal transmission according to claim 1, characterized in that: The characteristic values ​​of different non-fixed transmission users must be different at the same time, while the characteristic values ​​of different non-fixed transmission users can be the same at different times.

4. The spectrum sensing method for uplink non-orthogonal transmission according to claim 1, characterized in that: The detection threshold is determined based on the false alarm probability; the false alarm probability refers to the probability that the characteristic peak formed by the sum of noise and the signal of the fixed transmission user on the target frequency band is greater than a preset threshold.

5. The spectrum sensing method for uplink non-orthogonal transmission according to claim 1, characterized in that: The detection thresholds used may be the same or different for different non-fixed transmission users with higher priority than themselves.

6. The spectrum sensing method for uplink non-orthogonal transmission according to claim 1, characterized in that: When the non-fixed transmission user and the fixed transmission user use the target frequency band simultaneously, an uplink non-orthogonal merging transmission method is adopted.

7. A spectrum sensing system for uplink non-orthogonal transmission, applied to a non-fixed transmission user terminal, characterized in that: It includes a signal acquisition module, a calculation module, and a judgment module; The signal acquisition module is used to acquire the sensing signals of non-fixed transmission users with higher priority than itself on the target frequency band; The calculation module is used to calculate the characteristic peak values ​​of the non-fixed transmission user based on the sensing signal; The judgment module is used to determine that when the feature peak value is less than the detection threshold, the target frequency band is not occupied by a non-fixed transmission user with a higher priority, and the user has the right to use the target frequency band at the same time as a fixed transmission user; otherwise, it determines that the target frequency band has been occupied, and the user does not have the right to use the target frequency band at the same time as the fixed transmission user. The non-fixed transmission user is a user who is qualified to transmit information and can select the information to be transmitted according to their own needs, and is merged with the fixed transmission user in an uplink non-orthogonal form for transmission; the fixed transmission user is a user who transmits fixed information. Calculating the characteristic peak values ​​of the non-fixed transmission user based on the sensed signal includes the following steps: The sensing signal is cyclically shifted and conjugate processed, where the number of cyclic shifts is a characteristic value of the non-fixed transmission user. An autocorrelation operation is performed on the sensed signal and the conjugate signal after cyclic shifting to obtain the autocorrelation value; The autocorrelation value is used as the characteristic peak value.

8. A storage medium having a computer program stored thereon, characterized in that, When executed by the processor, the program implements the spectrum sensing method for uplink non-orthogonal transmission as described in any one of claims 1 to 6.

9. A non-fixed transmission user terminal, characterized in that, include: Processor and memory; The memory is used to store computer programs; The processor is used to execute the computer program stored in the memory to cause the non-fixed transmission user terminal to perform the uplink non-orthogonal transmission spectrum sensing method according to any one of claims 1 to 6.

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