A method for predicting performance of RFID system in linear tag distribution scenario

Abstract

The application discloses a kind of label linear distribution situation under RFID system performance prediction method, and method steps are as follows: S1: linear array distribution of RFID label, and the quantity of label is recorded n And interval;S2: record label operating wavelength λ And the wavelength number of label interval d λ ;S3: according to the quantity of label n And wavelength number d λ Mathematical model of solving label linear array distribution RFID system performance obtains the performance attenuation of the most obvious position of system performance attenuation;S4: the transmission power promotion multiple needed by activating all labels is determined by performance attenuation amount.The performance prediction method of the application has the advantages of small amount of calculation, fast calculation speed and general adaptability.

Description

Technical Field

[0001] The present invention relates to the technical field of radio frequency identification electronic tags, and in particular to a method for predicting RFID system performance under a linearly distributed tag situation. Background Art

[0002] Radio frequency identification (RFID) technology enables contactless communication between readers and tags. Due to its advantages, such as long read range, fast read speed, and long service life, it is widely used in various fields of socioeconomic development, such as logistics, transportation, collections, and production. However, in these practical applications, tags are often densely distributed, several wavelengths apart. Each tag is susceptible to interference from backlink scattered signals from other tags, disrupting the impedance matching between the chip and the tag antenna, significantly degrading the performance of the tag and RFID system. Therefore, it is necessary to use appropriate models to examine this effect, thereby providing a theoretical basis for the future application of small, passive, densely distributed RFID tags.

[0003] Existing technologies often use electromagnetic simulation software to simulate the working conditions of target tags under interference tags to analyze the impact of mutual coupling effects on RFID system links. However, the following problems still exist:

[0004] (1) There is a lack of research on the impact relationship between the overall distribution status of the RFID system and system performance.

[0005] (2) The simulation calculation is large and time-consuming. When the type of analysis label needs to be changed, the modeling workload is large. Summary of the Invention

[0006] Based on the technical problems existing in the background technology, the present invention proposes a method for predicting RFID system performance under the condition of linear distribution of tags, which has the advantages of small calculation amount, fast calculation speed and universal adaptability.

[0007] The present invention proposes a method for predicting RFID system performance under the condition of linear tag distribution, and the method steps are as follows:

[0008] S1: Distribute the RFID tags in a linear array and record the number n and spacing d of the tags;

[0009] S2: Record the tag working wavelength λ and calculate the number of wavelengths d between tags λ ;

[0010] S3: According to the number of tags n and the number of wavelengths d λ Solve the mathematical model of the RFID system performance based on the linear array of tags to obtain the performance degradation at the most obvious location.

[0011] S4: Determine the transmit power increase ratio required to activate all tags based on the performance degradation.

[0012] Preferably, the number of wavelengths d in S2 λ The calculation method is:

[0013]

[0014] Among them, d λ >0.16.

[0015] Preferably, the mathematical model of the performance of the RFID system with linear array distribution of tags in S3 is as follows:

[0016]

[0017] A2=1.45-25.98e -1.56n

[0018] Among them, τ min n,d λ Indicates the power transmission coefficient at the location where the tag group system performance degradation is most obvious.

[0019] Preferably, the calculation method of the performance degradation amount Δη at the position where the system performance degradation is most obvious is:

[0020] Δη(%)=1-τ min n,d λ .

[0021] Preferably, the calculation method of the transmission power increase ratio ΔP* in S4 is:

[0022]

[0023] Beneficial technical effects of the present invention:

[0024] The present invention proposes a method for predicting RFID system performance under the condition of linear tag distribution. The method uses the power transmission coefficient as an indicator for RFID system performance prediction and constructs a transmission model for the power transmission coefficient. Through this model, the location where the system performance degradation of the tag group is most obvious and the attenuation at this location can be determined. In addition, the transmission power increase factor required for the reader to activate all tags while considering the performance degradation caused by the mutual coupling effect can be determined. This performance prediction method has the advantages of low computational complexity, high calculation speed, and strong adaptability. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a flow chart of a method for predicting RFID system performance under the condition of linear tag distribution proposed by the present invention.

[0026] Figure 2This is a schematic diagram of the applicable scenarios of the RFID system performance prediction method under the condition of linear tag distribution proposed by the present invention. DETAILED DESCRIPTION

[0027] The present invention will be further explained below with reference to specific embodiments.

[0028] Reference Figure 1 and Figure 2 The performance prediction method of the linear array distributed RFID system proposed in the present invention has the following steps:

[0029] S1: Place six items with ALN-9662 RFID tags on a flat surface in a linear array with a spacing of 10 cm between tags.

[0030] S2: The wavelength of the system working is 32.8 cm according to the working status of the reader / writer, and the number of wavelengths of the tag spacing is calculated.

[0031] Wavelength d λ The calculation method is:

[0032]

[0033] According to calculation, the wavelength of the label spacing in this embodiment is 0.305.

[0034] S3: Substitute the number of tags obtained in S1 and the number of wavelengths obtained in S2 into the mathematical model of the linear array distributed RFID system performance to obtain the performance degradation at the location where the system performance degradation is most obvious.

[0035] The mathematical model of the linear array distributed RFID system performance is as follows:

[0036]

[0037] A2=1.45-25.98e -1.56n

[0038] Among them, τ min n,d λ The power transmission coefficient at the location where the performance of the tag group system is most significantly degraded is calculated as: min 6,0.305≈0.6638.

[0039] The performance degradation at the most obvious location of system performance degradation can be expressed as:

[0040] Δη(%)=1 min -τ min n,d λ .

[0041] Substitute τ min6,0.305 to obtain Δη(%)=1-τ min 6,0.305≈33.62%, that is, the performance of the tag at the location where the system performance decayed most significantly decayed by 33.62%.

[0042] S4: The performance degradation in S3 can be used to determine the transmission power increase factor ΔP* required for the reader to activate all tags while taking into account the performance degradation caused by the mutual coupling effect.

[0043]

[0044] Substitute τ min 6,0.305 is obtained

[0045] The present invention proposes a method for predicting RFID system performance under the condition of linear tag distribution. The method uses the power transmission coefficient as an indicator for RFID system performance prediction and constructs a transmission model for the power transmission coefficient. Through this model, the location where the system performance degradation of the tag group is most obvious and the attenuation at this location can be determined. In addition, the transmission power increase factor required for the reader to activate all tags while considering the performance degradation caused by the mutual coupling effect can be determined. This performance prediction method has the advantages of low computational complexity, high calculation speed, and strong adaptability.

Claims

1. A method for predicting RFID system performance under linear tag distribution, characterized in that: The steps are as follows: S1: Distribute the RFID tags in a linear array and record the number n and spacing d of the tags; S2: Record the tag working wavelength λ and calculate the number of wavelengths d between tags λ ; S3: According to the number of tags n and the number of wavelengths d λ Solve the mathematical model of the RFID system performance based on the linear array of tags to obtain the performance degradation at the most obvious location. The mathematical model of the performance of the RFID system with linear array distribution of tags in S3 is as follows: ； ； ； in, Indicates the power transmission coefficient at the location where the tag group system performance degradation is most obvious; The performance degradation at the location where the system performance degradation is most obvious The calculation method is: ； S4: Determine the transmit power increase ratio required to activate all tags based on the performance degradation. S4 transmission power increase ratio The calculation method is: 。 2. The method for predicting RFID system performance under linear tag distribution according to claim 1, characterized in that: The number of wavelengths d in S2 λ The calculation method is: ； Among them, d λ >0.16.

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