Method for evaluating outage performance in bistatic backscatter communication in an out-of-date channel

Abstract

The application discloses a kind of over time channel in two-station backscattering communication interruption performance evaluation method, it is related to wireless communication technical field, including: obtaining the estimated channel coefficient of each candidate tag, receiving end noise power and system parameter;According to the carrier frequency in system parameter, tag relative moving speed and the time delay between channel estimation and actual transmission, the correlation coefficient between estimated channel and actual transmission channel is determined;According to estimated channel coefficient, correlation coefficient and system parameter, the signal-to-interference-plus-noise ratio corresponding to each candidate tag is calculated, and according to selection diversity access scheme, target tag is selected from candidate tag for backscattering transmission;According to the signal-to-interference-plus-noise ratio corresponding to each candidate tag, obtain system reliability evaluation result, judge whether the current system configuration meets the preset communication reliability index, when not satisfied, adjust system parameter.The application can reduce the communication interruption risk of mobile multi-tag two-station backscattering communication system, improve system reliable transmission capability.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication technology, and in particular relates to a method for evaluating the interruption performance of bi-station backscatter communication in an outdated channel. Background Technology

[0002] With the surge in the number of IoT devices, the demand for low-power, high-spectral-efficiency wireless communication technologies is becoming increasingly urgent. Backscatter Communication (BackCom) has attracted widespread attention due to its ultra-low power consumption. Specifically, tags transmit information by modulating and reflecting radio frequency signals from the environment, eliminating high-power RF components such as oscillators and digital-to-analog converters, thus achieving microwatt-level power consumption. A review article published by Nguyen et al. in the *IEEE Internet of Things Journal* in 2021, and a survey published by Van Huynh et al. in *IEEE Communications Surveys & Tutorials* in 2018, both comprehensively illustrate the enormous application potential of this technology in IoT and 6G.

[0003] However, due to the two-way fading of the tag's reflected signal, the receiver's signal power is usually low, severely limiting system reliability. To improve performance and avoid multi-tag collisions, existing solutions often deploy multiple candidate tags, with the receiver selecting one based on a preset strategy. Among these, Selection Diversity Access (SDA) has become the mainstream approach in multi-tag systems because it selects the tag with the optimal channel gain each time. For example, Li et al. (2021) analyzed the physical layer security performance of backscatter communication in cognitive environments based on SDA in IEEE Transactions on Green Communications and Networking; Li and Peng et al. (2019) studied the system capacity under tag selection in IEEE Transactions on Vehicular Technology; Liu et al. (2021) derived the confidentiality interruption probability of the SDA scheme in IEEE Wireless Communications Letters; and Wang et al. (2023) discussed the multiple access design of coexisting wireless communication in IEEE Transactions on Wireless Communications. It is worth noting that all of the above studies are based on the assumption of ideal channel state information (CSI), that is, assuming that the channel state at the time of tag selection is completely consistent with the actual data transmission time.

[0004] However, in actual mobile deployments, the relative motion between tags and base stations or receivers can cause Doppler shift. Combined with the unavoidable processing or feedback delays between channel estimation, selection decisions, and actual transmission, the CSI obtained by the receiver during the selection phase often fails to reflect the true channel conditions during transmission. If the system continues to select tags based on this outdated CSI, it is highly likely to select tags whose actual links have deteriorated, resulting in a decrease in the received signal-to-interference-plus-noise ratio (SIR), a sharp increase in the probability of interruption, and even failure to meet preset reliability targets.

[0005] Current research has focused on the performance degradation caused by outdated CSI. Ali and Sharma (2025) examined the impact of RF hardware impairment and outdated CSI on backscatter systems in multi-tag environments in *IEEE Wireless Communications Letters*; Deng et al. (2021) analyzed the interruption performance of tag selection in reciprocal backscatter communication systems in the same journal. Both works confirm that outdated CSI significantly degrades system transmission performance, but they both use the independent and identically distributed Rayleigh channel model for mathematical derivation. This assumption ignores the fact that in real-world mobile scenarios, each link has different path loss and fading statistics due to spatial location differences, and is particularly unsuitable for multi-tag bi-station backscatter communication (BBC) systems—where the distance differences between different tags and the base station and receiver lead to non-uniform channel distribution across links.

[0006] Therefore, existing methods based on ideal CSI or simple identically distributed models are difficult to accurately assess and configure the reliable transmission capability of actual mobile multi-label BBC systems under outdated CSI conditions, and have obvious application limitations. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides a method for evaluating the performance of bi-station backscatter communication interruptions in obsolete channels. This method employs a Selection Diversity Access (SDA) scheme to determine the target tag for backscatter transmission, and the receiving end obtains the relevant parameters required by the system. Based on this, the impact of obsolete Channel State Information (CSI) on system reliability is evaluated, yielding system reliability assessment results under different parameter configurations.

[0008] This invention provides a method for evaluating the performance of bistation backscatter communication interruption in an outdated channel, comprising: Obtain the estimated channel coefficients, receiver noise power, and system parameters for each candidate label; Based on the carrier frequency, tag relative moving speed and time delay between channel estimation and actual transmission in the system parameters, determine the correlation coefficient between the estimated channel and the actual transmission channel; Based on the estimated channel coefficients, the correlation coefficients, and the system parameters, the signal-to-interference-plus-noise ratio (SINR) of each candidate label is calculated, and a target label is selected from the candidate labels for backscatter transmission according to the selected diversity access scheme. The system reliability assessment result is obtained based on the signal-to-interference-plus-noise ratio corresponding to each candidate tag, and the current system configuration is determined to meet the preset communication reliability index based on the system reliability assessment result. If it does not meet the index, at least one of the system parameters is adjusted.

[0009] Optionally, the estimated channel coefficients, receiver noise power, and system parameters for each candidate label are obtained. The specific process includes: During the channel estimation phase, the receiver obtains the estimated channel coefficients of the base station-to-tag link and the estimated channel coefficients of the tag-to-receiver link for each candidate tag. The receiver estimates the receiver noise power in idle time slots or pilot time slots; The receiving end reads pre-stored system parameters, including carrier frequency, base station transmit power, tag reflection coefficient, path loss parameters, tag relative moving speed, time delay between channel estimation and actual transmission, radio frequency operating frequency, path loss index, antenna gain, reflection efficiency factor, and time difference between channel estimation time and actual information transmission time.

[0010] Optionally, the correlation coefficient between the estimated channel and the actual transmission channel is determined, and the specific process includes: The maximum Doppler shift is calculated based on the carrier frequency and the relative moving speed of the tag. The product of the maximum Doppler frequency shift and the time delay is used as the independent variable of the first type zero-order Bessel function. The value of the first type zero-order Bessel function is calculated, and the calculated function value is used as the correlation coefficient between the estimated channel coefficient and the actual transmission channel coefficient.

[0011] Optionally, the signal-to-interference-plus-noise ratio (SIR) for each candidate label is calculated, and the specific process includes: Substitute the link channel coefficients of the actual transmission stage into the received signal expression, and organize the received signal into useful signal components, additional interference components introduced by outdated channel state information, and noise components. The sampled signal is filtered using matched filtering, and the useful signal power, additional interference power, and noise power after matched filtering are calculated respectively. The signal-to-interference-plus-noise ratio (SIR) for decoding the modulated signal of the tag is calculated based on the useful signal power, the additional interference power, and the noise power after matched filtering.

[0012] Optionally, a target label is selected from the candidate labels for backscatter transmission based on the chosen diversity access scheme. The specific process includes: Based on the estimated channel coefficient, correlation coefficient, transmit power, noise power, tag reflection coefficient, and path loss parameters of each candidate tag, the signal-to-interference-plus-noise ratio (SIR) of each candidate tag in the actual transmission stage is calculated. The candidate tag with the highest signal-to-interference-plus-noise ratio is selected as the target tag for backscatter transmission.

[0013] Optionally, the system reliability assessment result is obtained based on the signal-to-interference-plus-noise ratio (SIR) corresponding to each candidate label. The specific process includes: The interruption probability of each candidate tag is calculated based on the preset interruption threshold and the signal-to-interference-plus-noise ratio of each candidate tag. Under the conditions of outdated channel state information and independent non-co-distributed channels, the outage probability of each candidate tag is substituted into the system outage probability calculation process for selecting diversity access scheme to obtain the system outage probability value, and the system outage probability value is used as the system reliability assessment result.

[0014] Optionally, based on the system reliability assessment results, it is determined whether the current system configuration meets the preset communication reliability indicators. If it does not meet the indicators, at least one of the system parameters is adjusted. The specific process includes: Compare the calculated system outage probability value with the outage probability threshold corresponding to the preset communication reliability index; When the system interruption probability value is lower than or equal to the interruption probability threshold, it is determined that the current system configuration meets the preset communication reliability index. When the system interruption probability value is higher than the interruption probability threshold, it is determined that the current system configuration does not meet the preset communication reliability index. If the conditions are not met, adjust at least one of the following: base station transmit power, target data rate, number of candidate tags, tag deployment radius, or tag movement speed.

[0015] Optionally, at least one of the following can be adjusted: base station transmit power, target data rate, number of candidate tags, tag deployment radius, or tag movement speed. The specific process includes: When the system outage probability reaches the level of the outage, the reliable transmission capability of the system can be improved by shortening the time interval between channel estimation and actual transmission, reducing the target data rate, reducing the tag deployment radius, or limiting the tag movement speed. Alternatively, the risk of system outage can be reduced by increasing the number of candidate tags.

[0016] On the other hand, the present invention also provides an electronic device including a memory, a processor, and a computing program stored in the memory and executable on the processor, wherein the processor implements the method when executing the computing program.

[0017] On the other hand, the present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method.

[0018] Compared with the prior art, the present invention has the following advantages and technical effects: This invention addresses the technical deficiency in mobile multi-tag bi-station backscatter communication systems, where the time interval between channel estimation and actual data transmission leads to the receiver selecting tags based on outdated channel state information that are not actually optimal for the link. The invention provides an interruption performance evaluation method based on outdated channel state information. This method first obtains the estimated channel coefficients, receiver noise power, and system parameters for each candidate tag. Then, based on the carrier frequency, tag relative speed, and the time delay between channel estimation and actual transmission, it determines the correlation coefficient between the estimated channel and the actual transmission channel, thereby quantifying the degree of mismatch caused by channel changes over time, providing a foundation for accurate calculation of the signal-to-interference-plus-noise ratio (SIR). Based on this, the method calculates the actual SIR for each candidate tag according to the estimated channel coefficients, correlation coefficients, and system parameters. Finally, it employs a selection diversity access scheme to select target tags for backscatter transmission, allowing the tag selection process to consider the impact of channel aging and overcoming the link quality degradation problem caused by directly selecting tags based on outdated channel state information in existing technologies.

[0019] This method further obtains the system outage probability value based on the signal-to-interference-plus-noise ratio (SINR) of each candidate tag as a reliability assessment result. Based on this assessment result, it determines whether the current system configuration meets preset communication reliability indicators. If not, it adjusts at least one parameter among the base station transmit power, target data rate, number of candidate tags, tag deployment radius, or tag movement speed. This allows engineers to optimize the system configuration in a targeted manner based on the reliability assessment results. Through this method, the present invention achieves accurate assessment of the outage performance of a mobile multi-tag bi-station backscatter communication system under outdated channel state information conditions. It solves the technical problem that existing technologies, due to the assumption of ideal channel state information or independent and identically distributed channel models, cannot effectively guide the actual system configuration, thus effectively reducing the risk of communication outages and improving the system's reliable transmission capability. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of a mobile multi-tag bi-station backscatter communication system provided in an embodiment of the present invention; Figure 2 Simulation results of the impact of different channel correlation coefficients, candidate tag numbers, and transmit power on system outage performance provided for embodiments of the present invention; Figure 3 The simulation results are shown in the figure, which illustrates the impact of different tag deployment area radii on system outage performance in an embodiment of the present invention. Detailed Implementation

[0021] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0022] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0023] Example 1 This embodiment provides a method for evaluating the performance of bi-station backscatter communication interruption in an outdated channel, the method comprising the following steps: Step 1: The receiver obtains the estimated channel coefficients of each candidate tag and estimates the receiver noise power. At the same time, the receiver reads the system parameters that are pre-stored or set by engineers. The system parameters include carrier frequency, base station transmit power, tag reflection coefficient, path loss parameters, tag relative moving speed, and time delay between channel estimation and actual transmission. Step 2: Using the system parameters obtained in Step 1, determine the correlation coefficient between the estimated channel and the actual transmission channel according to the Jakes model; Step 3: Based on the system parameters obtained in Step 1 and Step 2, calculate the system signal-to-interference-plus-noise ratio corresponding to each candidate label, and select the target label from the candidate labels for backscatter transmission according to the Selective Diversity Access (SDA) scheme. Step four involves evaluating the impact of outdated Channel State Information (CSI) on system reliability and obtaining system reliability assessment results under different parameter configurations. Subsequently, it is determined whether the current system configuration meets the preset communication reliability indicators. If the determination result indicates that the current configuration cannot meet the reliability requirements, engineers can adjust at least one of the following: base station transmit power, target data rate, number of candidate tags, tag deployment radius, or tag movement speed, to make the system meet the preset communication reliability indicators again.

[0024] As a feasible implementation method, the specific steps include: like Figure 1 As shown, the BBC system of this invention includes a base station (BS), a receiver (R), and N candidate backscatter tags. Each candidate tag can be randomly distributed within a circular area with BS as the center and radius r. To evaluate system reliability, let... and Representing links respectively and The actual channel coefficients at the moment of information transmission. In the model under consideration, all channel coefficients follow a Rayleigh distribution, i.e.: and ,in The distribution is represented by a complex Gaussian distribution. Each link is independent and remains quasi-static within a single transmission time slot, while considering both large-scale path loss and small-scale fading. Therefore, the channel gain of the link can be expressed as... and ,That Indicates the radio frequency operating frequency. Represents the speed of light. and They represent BS to and Distance to R and These represent the path loss indices for the corresponding links. , and These represent the antenna gains at BS, tag, and R, respectively.

[0025] Outdated CSI model: In the considered model, the positions of BS and R remain fixed, while the candidate tag is in a moving state. During the channel estimation phase, R acquires and stores the estimated channel coefficients for the BS-to-tag link and the tag-to-R link; simultaneously, R records the channel estimation time, data transmission time, and the relative moving speed between the tag and BS / R. Since there is a time interval between tag selection or channel estimation and actual information transmission, the estimated channel coefficients may not match the actual transmission channel. Therefore, to closely approximate actual system performance, this invention establishes a correlation between the estimated channel coefficients and the channel coefficients during the actual transmission phase based on the Jakes model: (1) (2) In equations (1) and (2), and These represent the channel error terms introduced by the CSI becoming outdated; and Let represent the correlation coefficients between the estimated channel coefficients and the actual transmission channel coefficients in the BS-tag link and the tag-R link, respectively. The closer the correlation coefficient is to 1, the closer the estimated channel is to the actual transmission channel; the smaller the correlation coefficient is, the more obvious the link mismatch caused by tag movement and transmission delay is. The receiver can calculate the maximum Doppler shift based on the carrier frequency, the relative movement speed of the tag, and the time delay between the channel estimation and the actual transmission, and determine the channel correlation coefficient according to equation (3).

[0026] (3) In equation (3), Desirable or , This indicates the maximum Doppler frequency shift of the corresponding link. This represents the time delay between the channel estimate and the actual information transmission in the corresponding link. This represents the zeroth-order Bessel function of the first kind. The maximum Doppler shift can be calculated from the relative velocity and carrier frequency; the time delay is determined by the time difference between the channel estimation time and the actual information transmission time; the value of the zeroth-order Bessel function of the first kind can be obtained by R through a preset calculation program, or by calling a pre-stored function table. Therefore, R can obtain the specific value of the channel correlation coefficient.

[0027] Received signal processing and signal-to-interference-plus-noise ratio: During the current transmission time slot, if R selects a certain tag for information transmission based on the access decision, the base station sends a radio frequency excitation signal, and the tag modulates the information to be transmitted onto the reflected signal and reflects it to R. The received signal at R can be expressed as equation (4).

[0028] (4) The parameters in equation (4) all correspond to configurable or measurable physical quantities in actual communication equipment, including BS transmit power, BS transmit RF excitation signal, tag reflection modulation signal, noise power at R, tag fixed reflection coefficient, and reflection efficiency factor. Among them, transmit power and reflection coefficient can be directly set to specific values, and noise power can be estimated by R in idle time slots or pilot time slots.

[0029] Substituting the actual transmission stage link channel coefficients given in equations (1) and (2) into equation (4), and reorganizing the received signal into useful signal components, additional interference components introduced by CSI obsolescence, and noise components, the signal received by R is expressed as equation (5).

[0030] (5) In equation (5), The first term represents the useful signal component received by R, while the remaining terms represent additional interference components introduced by outdated CSI. R utilizes... Perform matched filtering on the sampled signal, where, and They represent and The complex conjugate of the signal is then calculated. Next, the useful signal power, the additional interference power, and the noise power after matched filtering are calculated respectively. Finally, by combining the above power terms, the signal-to-interference-plus-noise ratio (SIR) for decoding the tag modulation signal is obtained, as shown in equation (6).

[0031] (6) In equation (6), the input signal-to-noise ratio The signal-to-interference-plus-noise ratio (SNR) is determined by both the transmit power at BS and the noise power at R. Under high SNR conditions, the SNR expression in equation (6) can be approximated as equation (7): (7) Tag access and reliability assessment: To improve the reliable transmission capability of multi-tag BBC systems in mobile scenarios, this invention adopts an SDA access scheme. Specifically, based on the aforementioned estimated channel coefficients, channel correlation coefficients, transmit power, noise power, tag reflection coefficients, and path loss parameters, the signal-to-interference-plus-noise ratio (SIR) of each candidate tag in the actual transmission stage is calculated, and the tag with the higher SIR is selected as the target tag for backscatter transmission. Let the tag index corresponding to the selected backscatter tag be i. Then it can be expressed as equation (8).

[0032] (8) To facilitate interruption probability calculation at the receiving end, the following intermediate calculation variables are pre-set: , , , , , , The statistical distribution parameters of the relevant link gain are stored in R. R calculates the system outage probability value under the SDA scheme according to the preset outage threshold and the signal-to-interference-plus-noise ratio of each candidate tag, according to Equation (9).

[0033] (9) When performing the calculation shown in equation (9), the receiving end can select the corresponding calculation branch according to the values ​​of the relevant intermediate variables in order to obtain the specific value of the system interruption probability.

[0034] (10) (11) (12) (13) (14) When R executes this calculation process, Equation (12) can be equivalently processed by variable substitution and preset Bessel function calculation module to reduce the complexity of the interruption probability numerical calculation and obtain the calculation results shown in Equations (13) and (14).

[0035] The receiver can obtain the interruption probability value corresponding to any candidate tag by following the preset calculation process shown in equations (9) to (14), as shown in equation (15).

[0036] (15) In equation (15), the threshold signal-to-noise ratio Determined by the target data rate.

[0037] In the SDA scheme, tags with a high signal-to-interference-plus-noise ratio (SIR) are selected for transmission. If the selected tag is still in an interrupted state, it indicates that all candidate links have failed to meet the reliable transmission requirements. Therefore, under the conditions of outdated CSI and independent non-co-distributed channels, the interruption probability of the multi-tag bi-station backscatter communication system can be calculated by equation (16) and used as a basis for engineers to judge whether the current system configuration meets the preset reliability requirements.

[0038] (16) Under high signal-to-noise ratio conditions At this point, the expression for the probability of interruption of any link is... No longer contains Therefore, the system outage probability forms an outage plane in the high signal-to-noise ratio region. At this point, engineers can improve the system's reliable transmission capability by increasing the number of candidate tags, shortening the time interval between channel estimation and actual transmission, reducing the target data rate, decreasing the tag deployment radius, or limiting tag movement speed. Furthermore, since the system outage probability corresponding to the SDA scheme is jointly determined by the outage probabilities of all candidate links, increasing the number of candidate tags usually helps reduce the risk of system outage.

[0039] R can also obtain the correspondence between the number of candidate tags and the reliability gain according to equations (17) to (20), which can be used as a reference for engineers to determine the number of candidate tags to deploy.

[0040] (17) (18) (19) (20) Implementation effect verification: To verify the effectiveness of the method of the present invention, in an example scenario, the base station (BS) and the receiver (R) are deployed at preset coordinate positions, and N candidate tags are randomly distributed within a circular area centered on the BS. The receiver collects and configures the following physical parameters: antenna gain at the BS, tags, and R; BS RF operating frequency; path loss index of the link from the BS to the tag and the link from the tag to R; reflection efficiency factor; tag reflection coefficient; target data rate; and noise power at R. Based on these parameters, the receiver calculates the outage probability under different transmit powers, different channel correlation coefficients, different numbers of candidate tags, and different tag deployment radii, and outputs the corresponding system reliability assessment results to verify the effectiveness of the method of the present invention in mobile multi-tag BBC scenarios.

[0041] Depend on Figure 2 It is evident that when the channel correlation coefficient is low, the system is more prone to outages caused by outdated CSIs, indicating that simply increasing the transmit power cannot continuously reduce the outage probability. Furthermore, as the number of candidate tags increases, the number of selectable candidate links increases, and the outage probability decreases accordingly, demonstrating that the method of this invention can improve reliable transmission capabilities by configuring the number of candidate tags. Therefore, both the channel correlation coefficient and the number of candidate tags can serve as important bases for improving system reliability.

[0042] Depend on Figure 3 It is known that, with a fixed channel correlation coefficient and number of candidate tags, as the radius of the tag deployment area increases, the distance between some tags and the BS increases, the first-hop link path loss increases, the incident RF signal received by the tags weakens, and the backscattered signal power decreases accordingly, thus increasing the probability of outage. Therefore, when the system configuration does not meet the preset communication reliability indicators, engineers can improve system reliability by reducing the tag deployment radius, increasing the BS transmission power, or reducing the target data rate, based on the reliability assessment results. Figure 3 It also shows that the higher the target data rate, the higher the link quality required for the system to meet the conditions for successful transmission; therefore, when the link conditions are insufficient, the system reliability can be improved by reducing the target data rate.

[0043] In summary, the proposed method for evaluating the performance of bi-station backscatter communication interruption in outdated channels introduces a channel correlation coefficient based on the Jakes model to quantify the channel mismatch caused by outdated channel state information. It also provides a numerical calculation process for the system interruption probability under independent non-co-distributed channel conditions by combining a diversity access scheme, thus achieving an accurate evaluation of the reliability of mobile multi-tag bi-station backscatter communication systems. Figure 2 and Figure 3The experimental results shown verify the effectiveness of the method of this invention from different perspectives, demonstrating that the method can accurately reflect the impact of factors such as channel correlation coefficient, number of candidate tags, transmit power, and tag deployment radius on system outage performance. Engineers can flexibly adjust system parameters such as base station transmit power, target data rate, number of candidate tags, tag deployment radius, or tag movement speed based on these evaluation results to ensure the system meets preset communication reliability indicators. This invention effectively reduces the risk of communication outages caused by outdated channel state information, significantly improves the reliable transmission capability of mobile multi-tag bi-station backscatter communication systems, and provides a reliable theoretical basis and configuration guidance for practical engineering deployment.

[0044] On the other hand, this embodiment also provides an electronic device, including a memory, a processor, and a computing program stored in the memory and executable on the processor, wherein the processor implements the method when executing the computing program.

[0045] On the other hand, this embodiment also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method.

[0046] The above are merely preferred embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for evaluating the performance of bistation backscatter communication interruption in an outdated channel, characterized in that, include: Obtain the estimated channel coefficients, receiver noise power, and system parameters for each candidate label; Based on the carrier frequency, tag relative moving speed and time delay between channel estimation and actual transmission in the system parameters, determine the correlation coefficient between the estimated channel and the actual transmission channel; Based on the estimated channel coefficients, the correlation coefficients, and the system parameters, the signal-to-interference-plus-noise ratio (SINR) of each candidate label is calculated, and a target label is selected from the candidate labels for backscatter transmission according to the selected diversity access scheme. The system reliability assessment result is obtained based on the signal-to-interference-plus-noise ratio corresponding to each candidate tag, and the current system configuration is determined to meet the preset communication reliability index based on the system reliability assessment result. If it does not meet the index, at least one of the system parameters is adjusted.

2. The method according to claim 1, characterized in that, The process of obtaining the estimated channel coefficients, receiver noise power, and system parameters for each candidate label includes: During the channel estimation phase, the receiver obtains the estimated channel coefficients of the base station-to-tag link and the estimated channel coefficients of the tag-to-receiver link for each candidate tag. The receiver estimates the receiver noise power in idle time slots or pilot time slots; The receiving end reads pre-stored system parameters, including carrier frequency, base station transmit power, tag reflection coefficient, path loss parameters, tag relative moving speed, time delay between channel estimation and actual transmission, radio frequency operating frequency, path loss index, antenna gain, reflection efficiency factor, and time difference between channel estimation time and actual information transmission time.

3. The method according to claim 1, characterized in that, The process of determining the correlation coefficient between the estimated channel and the actual transmission channel includes: The maximum Doppler shift is calculated based on the carrier frequency and the relative moving speed of the tag. The product of the maximum Doppler frequency shift and the time delay is used as the independent variable of the first type zero-order Bessel function. The value of the first type zero-order Bessel function is calculated, and the calculated function value is used as the correlation coefficient between the estimated channel coefficient and the actual transmission channel coefficient.

4. The method according to claim 1, characterized in that, The specific process for calculating the signal-to-interference-plus-noise ratio (SIR) for each candidate label includes: Substitute the link channel coefficients of the actual transmission stage into the received signal expression, and organize the received signal into useful signal components, additional interference components introduced by outdated channel state information, and noise components. The sampled signal is filtered using matched filtering, and the useful signal power, additional interference power, and noise power after matched filtering are calculated respectively. The signal-to-interference-plus-noise ratio (SIR) for decoding the modulated signal of the tag is calculated based on the useful signal power, the additional interference power, and the noise power after matched filtering.

5. The method according to claim 1, characterized in that, Based on the selected diversity access scheme, a target label is selected from the candidate labels for backscatter transmission. The specific process includes: Based on the estimated channel coefficient, correlation coefficient, transmit power, noise power, tag reflection coefficient, and path loss parameters of each candidate tag, the signal-to-interference-plus-noise ratio (SIR) of each candidate tag in the actual transmission stage is calculated. The candidate tag with the highest signal-to-interference-plus-noise ratio is selected as the target tag for backscatter transmission.

6. The method according to claim 1, characterized in that, The system reliability assessment result is obtained based on the signal-to-interference-plus-noise ratio (SIR) corresponding to each candidate label. The specific process includes: The interruption probability of each candidate tag is calculated based on the preset interruption threshold and the signal-to-interference-plus-noise ratio of each candidate tag. Under the conditions of outdated channel state information and independent non-co-distributed channels, the outage probability of each candidate tag is substituted into the system outage probability calculation process for selecting diversity access scheme to obtain the system outage probability value, and the system outage probability value is used as the system reliability assessment result.

7. The method according to claim 1, characterized in that, Based on the system reliability assessment results, determine whether the current system configuration meets the preset communication reliability indicators. If not, adjust at least one of the system parameters. The specific process includes: Compare the calculated system outage probability value with the outage probability threshold corresponding to the preset communication reliability index; When the system interruption probability value is lower than or equal to the interruption probability threshold, it is determined that the current system configuration meets the preset communication reliability index. When the system interruption probability value is higher than the interruption probability threshold, it is determined that the current system configuration does not meet the preset communication reliability index. If the conditions are not met, adjust at least one of the following: base station transmit power, target data rate, number of candidate tags, tag deployment radius, or tag movement speed.

8. The method according to claim 7, characterized in that, Adjusting at least one of the following: base station transmit power, target data rate, number of candidate tags, tag deployment radius, or tag movement speed, the specific process includes: When the system outage probability reaches the level of the outage, the reliable transmission capability of the system can be improved by shortening the time interval between channel estimation and actual transmission, reducing the target data rate, reducing the tag deployment radius, or limiting the tag movement speed. Alternatively, the risk of system outage can be reduced by increasing the number of candidate tags.

9. An electronic device comprising a memory, a processor, and a computing program stored in the memory and executable on the processor, characterized in that, When the processor executes the computing program, it implements the method of any one of claims 1-8.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by a processor, it implements the method of any one of claims 1-8.

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