Payment Data Interaction and Transmission Method for Smart Terminals

Abstract

The present invention relates to the technical field of signal transmission, and specifically relates to a method for interactive transmission of payment data for intelligent terminals. The method includes: obtaining the peaks in the spectrogram corresponding to the test signals received by the NFC payment ring, and screening out the high peaks, and then judging whether there is Bluetooth signal interference according to the peak discreteness; if there is Bluetooth signal interference, setting an initial filtering threshold for band-pass filtering; obtaining the isolation effect and the continuity factor, and then obtaining the signal integrity; screening the high peaks to obtain the sudden peaks; obtaining the degree of noise existence by using the number and abruptness of the sudden peaks within the initial filtering threshold; obtaining the filtering effect of the initial filtering threshold according to the signal integrity and the degree of noise existence; updating the initial filtering threshold to obtain an updated filtering threshold; and selecting the updated filtering threshold with the maximum filtering effect for filtering. This application can reduce the interference suffered when the NFC ring and the NFC terminal interact with payment signals.

Description

Technical Field

[0001] The present invention relates to the technical field of signal transmission, and particularly to a method for interactive transmission of payment data for intelligent terminals. Background Art

[0002] The NFC payment ring is a smart wearable device with a built-in Near Field Communication (NFC) chip and can be used for contactless payment. It is similar to the mobile payment function of an NFC payment card or a smart phone and can perform quick payment on an NFC-enabled POS machine (NFC terminal) without taking out the mobile phone or bank card. Most traditional NFC payment rings directly write payment information such as card numbers and passwords through the NFC chip. With the development of technology, data can be written into the NFC payment ring by installing an MCU chip in the payment ring to achieve data writing from a mobile phone intelligent terminal to the NFC payment ring.

[0003] The data transmission and interaction between the MCU chip and the mobile phone terminal are realized through Bluetooth. However, the short-range Bluetooth data transmission will affect the data transmission and interaction of the NFC chip, and a filter is often required to filter and clean the transmission data. The transmission signal of NFC is around 13.56 MHz, and existing algorithms usually can use band-pass filtering to filter out frequency signals outside the fixed filtering threshold around 13.56 MHz.

[0004] However, the filtering effect of the band-pass filtering with a fixed filtering threshold in the prior art is unstable. The band-pass filtering with a higher threshold may introduce too many interference signals, and the band-pass filtering with a lower threshold may filter out the original NFC payment signal. Therefore, the band-pass filtering with a fixed filtering threshold has poor adaptability to NFC payment signal transmission in different scenarios, and there is an urgent need for a stable and highly adaptable filtering method. Summary of the Invention

[0005] In order to solve the above technical problems, the purpose of the present invention is to provide a method for interactive transmission of payment data for intelligent terminals, and the specific technical solution adopted is as follows:

[0006] An embodiment of the present invention provides a method for interactive transmission of payment data for intelligent terminals, and the method includes:

[0007] Convert the test signal received by the NFC payment ring into a spectrogram; obtain the peaks in the spectrogram, and screen out the high peaks, and obtain the peak discreteness according to the distance between each high peak and the two adjacent high peaks on the left and right;

[0008] Judge whether there is Bluetooth signal interference according to the peak discreteness; if there is Bluetooth signal interference, set the initial filtering threshold of the band-pass filtering for filtering;

[0009] Obtain the isolation effect based on the distance between the left and right adjacent peaks of the left and right thresholds in the initial filtering threshold; obtain the continuity degree factor based on the peak value difference between every two adjacent peaks inside and outside the initial filtering threshold; multiply the isolation effect and the continuity degree factor to obtain the signal integrity;

[0010] Screen the peaks according to the peak value difference between each peak and its adjacent peak to obtain the prominent peaks; obtain the noise existence degree by using the number and prominence degree of the prominent peaks within the initial filtering threshold; obtain the filtering effect of the initial filtering threshold according to the signal integrity and the noise existence degree;

[0011] Update the initial filtering threshold to obtain the updated filtering threshold; select the updated filtering threshold with the maximum filtering effect for filtering.

[0012] Preferably, obtain the peaks in the spectrogram and screen out the prominent peaks, including:

[0013] Use the AMPD peak search algorithm to obtain all the peaks in the spectrogram; normalize the peak values of all the peaks to obtain the peak values of the normalized peaks; set a screening threshold. When the threshold of the normalized peak is less than or equal to the screening threshold, the peak is a low peak. When the threshold of the normalized peak is greater than the screening threshold, the peak is a prominent peak.

[0014] Preferably, obtain the peak discreteness degree according to the distance between each prominent peak and its two adjacent prominent peaks on the left and right, including:

[0015] Obtain the distances between each prominent peak in the spectrogram and its two adjacent prominent peaks on the left and right, and form a distance set; calculate the variance of the distance set as the peak discreteness degree.

[0016] Preferably, judge whether there is Bluetooth signal interference according to the peak discreteness degree, including:

[0017] Normalize the peak discreteness degree, set a first threshold. If the normalized peak discreteness degree is greater than or equal to the first threshold, there is Bluetooth signal interference.

[0018] Preferably, obtain the isolation effect, including:

[0019] Obtain the sum of the distance between the two adjacent peaks on the left and right of the left threshold in the initial filtering threshold and the distance between the two adjacent peaks on the left and right of the right threshold, and record it as the isolation effect.

[0020] Preferably, obtain the continuity degree factor according to the peak value difference between every two adjacent peaks inside and outside the initial filtering threshold, including:

[0021] Obtain the average of the absolute values of the peak differences between every two adjacent peaks within the initial filtering threshold and take the reciprocal to obtain the continuity degree within the threshold; obtain the average of the absolute values of the peak differences between every two adjacent peaks outside the initial filtering threshold and take the reciprocal to obtain the continuity degree outside the threshold; the ratio of the continuity degree within the threshold to the continuity degree outside the threshold is the continuity degree factor.

[0022] Preferably, screen the peaks to obtain prominent peaks according to the peak differences between each peak and its adjacent peaks, including:

[0023] Respectively calculate the sum of the absolute values of the differences between the peak of a peak and the peaks of its two adjacent peaks on the left and right, normalize the result after summation to obtain the neighborhood distribution eigenvalue of the peak; if the neighborhood distribution eigenvalue of the peak is greater than the segmentation threshold, then the peak is a prominent peak.

[0024] Preferably, obtain the noise presence degree based on the number and prominence degree of prominent peaks within the initial filtering threshold, including:

[0025] Calculate the sum of the absolute values of the differences between the peak of a prominent peak and the peaks of its two adjacent peaks on the left and right, which is denoted as the adjacent difference of the prominent peak; obtain the sum of the adjacent differences of all prominent peaks within the initial filtering threshold, which is denoted as the prominence degree; multiply the number of prominent peaks within the initial filtering threshold by the prominence degree to obtain the noise presence degree.

[0026] Preferably, obtain the filtering effect of the initial filtering threshold according to the signal integrity and the noise presence degree, including:

[0027] Normalize the reciprocal of the noise presence degree and the signal integrity respectively and then sum them to obtain the filtering effect of the initial filtering threshold.

[0028] Preferably, update the initial filtering threshold to obtain an updated filtering threshold, including:

[0029] Set an update amplitude, and synchronously update the left threshold and the right threshold in the initial filtering threshold using the update amplitude to obtain the updated filtering threshold; each update includes increasing the left threshold and decreasing the right threshold, and the increasing or decreasing amplitude is the update amplitude.

[0030] The embodiments of the present invention have at least the following beneficial effects: Before the NFC payment ring transmits the payment signal to the NFC terminal, the present application first transmits a test signal, and then converts the test signal received by the NFC payment ring into a spectrogram. By analyzing the peaks in the spectrogram, it is determined whether filtering processing is required. For normal transmissions that do not require filtering processing, the transmission efficiency can be improved; further, for those that are interfered by Bluetooth signals and require filtering processing, based on the characteristic differences between the NFC modulation signal and the Bluetooth interference signal, the signal integrity after filtering is obtained according to the peaks within the filtering threshold and the peaks at the boundaries of the filtering threshold (left threshold and right threshold) in the spectrogram of the test signal to ensure the integrity of the NFC modulation signal after filtering. Then, the spike peaks among the peaks are obtained, and the degree of remaining noise after filtering is obtained according to the spike peaks. Furthermore, by combining the two aspects, the advantages and disadvantages of the filtering threshold are evaluated from the two aspects of signal integrity and the remaining situation of noise after filtering. Finally, the initial filtering threshold is updated, and based on the filtering effect corresponding to the filtering threshold after each update, the optimal filtering threshold is selected, so as to obtain a relatively accurate band-pass filtering threshold during the transmission of the payment signal, and improve the integrity and accuracy of the payment signal in the interactive transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following-described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0032] Figure 1 It is a flowchart of a method for payment data interactive transmission for a smart terminal provided by an embodiment of the present invention;

[0033] Figure 2 It is a schematic diagram of a spectrogram of a method for payment data interactive transmission for a smart terminal provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] In order to further elaborate on the technical means and effects adopted by the present invention to achieve the intended invention purpose, the following, in combination with the accompanying drawings and preferred embodiments, details the specific embodiments, structures, features, and effects of a method for payment data interactive transmission for a smart terminal proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. In addition, the specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs.

[0036] The following specifically describes the specific solution of a payment data interaction and transmission method for a smart terminal provided by the present invention in conjunction with the accompanying drawings. Embodiment

[0037] The main application scenario of the present invention is:

[0038] During the interaction payment process between the NFC payment ring and the NFC terminal, if the smart terminal is used to adjust the payment data of the NFC payment ring, the NFC payment signal may be interfered by Bluetooth data, resulting in inaccurate transmission of payment data. A filter is required for filtering. The fixed threshold of the existing band-pass filtering algorithm has an unstable filtering effect on Bluetooth interference, and the threshold needs to be adjusted according to the real-time situation of Bluetooth interference noise in the delivery scenario.

[0039] Please refer to Figure 1 , which shows a flowchart of a method for payment data interaction and transmission for a smart terminal provided by an embodiment of the present invention. The method includes the following steps:

[0040] Step S1, convert the test signal received by the NFC payment ring into a spectrogram; obtain the peaks in the spectrogram, and screen out the high peaks, and obtain the peak discreteness according to the distance between each high peak and the two adjacent high peaks on the left and right.

[0041] Before the NFC payment ring transmits the formal payment signal to the NFC terminal, it needs to transmit multiple groups of test signals, and the content of the test signals is the same as the content of the payment signal.

[0042] After receiving the test signal, the NFC terminal sends a reply signal to the NFC payment ring, and the signal content is the same as the test signal. After receiving the test reply signal, the NFC payment ring performs subsequent analysis to detect the noise interference situation in the transmission channel.

[0043] The transmission signal during the process is mainly a modulation signal in the range near 13.56 MHz, and the format is time-series data. Each data point is the signal intensity corresponding to the moment. For the test signal received by the NFC payment ring, the Fourier transform is used to convert the time-series data into a spectrogram, where the horizontal axis of the spectrogram is the frequency and the vertical axis is the signal intensity.

[0044] Before sending the payment signal in NFC, a test signal is sent first to test the channel. If there is no channel anomaly, the signal transmission is directly carried out; otherwise, if there is a channel anomaly, the filtering threshold corresponding to the adaptive band-pass filter is obtained according to the anomaly characteristics. In the spectrogram of the test signal, it usually contains NFC modulation signal, white noise, and Bluetooth interference signal in the current scenario, such as Figure 2 shown. The NFC modulation signal is usually concentrated near the carrier frequency of 13.56 MHz. The main energy is distributed near the carrier frequency and its sidebands, and it has the strongest signal intensity at 13.56 MHz. The signal intensity of the modulation frequency signal gradually decreases on both sides in turn. In addition to the modulation signal, there are many white noises with relatively small signal intensities distributed in the spectrum, evenly distributed in the frequency domain. The Bluetooth interference signal also has a relatively strong signal intensity. Unlike white noise, it is not evenly distributed but locally concentrated, usually having multiple concentrated frequency points.

[0045] Furthermore, the AMPD peak search algorithm is used to obtain all the peaks in the spectrogram. Most of the peaks in the spectrogram are white noise peaks, which are lower than the peaks caused by the modulation signal and Bluetooth interference signal. Therefore, the peaks of all the peaks are normalized to obtain the peaks of the normalized peaks. After normalization, the low peaks of white noise and the high peaks caused by NFC modulation signal or suspected Bluetooth transmission can be obtained at both ends respectively. Then, a screening threshold is set. When the threshold of the normalized peak is less than or equal to the screening threshold, the peak is a low peak; when the threshold of the normalized peak is greater than the screening threshold, the peak is a high peak. The reference value of the screening threshold is 0.5, and the implementer can adjust it according to the actual situation. For example, a Rayleigh distribution test is performed on the low peaks, and the threshold is adjusted according to the test results.

[0046] For the obtained high peaks, according to the global distribution characteristics of the high peaks, if all the high peaks are concentrated in the global distribution of the spectrogram, it means that all the high peak waves are concentrated near the main carrier frequency, and there is no anomaly in the current channel; if there is a certain degree of discrete distribution of the high peaks, the degree of global high peak distribution aggregation is low, indicating that there is suspected Bluetooth interference in the current signal, and filtering processing is required.

[0047] Obtain the distance between each high peak in the spectrogram and the two adjacent high peaks on the left and right to form a distance set. The distance is also the horizontal axis distance between two high peaks. Calculate the variance of the distance set as the peak discrete degree. The greater the peak discrete degree, the more discrete the high peak distribution in the current signal spectrogram, indicating that there is suspected Bluetooth signal interference in the channel.

[0048] Step S2, judge whether there is Bluetooth signal interference according to the peak discrete degree; if there is Bluetooth signal interference, set the initial filtering threshold of the band-pass filter for filtering.

[0049] Since when the channel is normal, the signal frequency distribution of NFC in the spectrogram is concentrated, and the variance of the interval distance between peaks is extremely low compared to the variance of the interval distance of the Bluetooth noise signal; further, the degree of peak discreteness is normalized, and a first threshold is set to separate the case of normal channel from the case of Bluetooth signal interference in the channel. If the normalized degree of peak discreteness is greater than or equal to the first threshold, there is Bluetooth signal interference. The reference value of the first threshold is 0.5, and the implementer can adjust it according to the actual situation.

[0050] Since when the channel is normal, the signal frequency distribution of NFC in the spectrogram is concentrated, and the variance of the interval distance between peaks is extremely low compared to the variance of the interval distance of the Bluetooth noise signal, after normalization, the degree of peak discreteness of the Bluetooth noise signal and the suspected abnormality degree distribution without Bluetooth signal show a two-level differentiation trend. Therefore, the first threshold is set to the midpoint 0.5 here, which can basically separate the normal channel from the abnormal situation in the channel. When the normalized value of the peak discreteness of the channel is greater than or equal to 0.5, it is considered that there is Bluetooth interference abnormality in the current transmission channel.

[0051] If there is interference from Bluetooth signals, filtering processing needs to be performed using a band-pass filter. Therefore, an initial filtering threshold is set, and band-pass filtering is performed based on the initial filtering threshold. There are two thresholds for the filtering threshold of band-pass filtering. In actual signal data filtering, they are usually two centrally symmetric filtering thresholds. The frequency waves outside the filtering threshold are filtered out, and the frequency wave signals within the two filtering thresholds are retained. The two thresholds of the initial filtering threshold are divided into a left threshold and a right threshold.

[0052] Step S3, obtain the isolation effect according to the distance between the left and right adjacent peaks of the left threshold and the right threshold in the initial filtering threshold; obtain the continuity factor according to the peak difference between every two adjacent peaks within and outside the initial filtering threshold; multiply the isolation effect and the continuity factor to obtain the signal integrity.

[0053] After filtering, the generally desired result is to filter out the noise signals brought by Bluetooth interference as much as possible while retaining the complete NFC data as much as possible. Therefore, an evaluation model is constructed here through two indicators of the data distribution characteristics in the frequency domain. One is to test the integrity of the NFC modulation signal in the signal. The more complete the NFC modulation signal within the filtering threshold, the lower the loss degree of the original transmission information by the filtering, and the more complete the retained information; the other is the existence degree of the noise signal. The lower the existence degree of the noise signal within the band-pass threshold, the better the noise filtering effect corresponding to this threshold, so as to evaluate the filtering effect of the band-pass filter.

[0054] The integrity of the NFC modulation signal in the test signal is mainly to detect and avoid the situation where the filtering threshold is located within the NFC modulation signal region, cutting off the NFC modulation signal and resulting in an incomplete signal. The integrity of the NFC modulation signal is obtained by the ratio of the continuity of the high peaks within the threshold to the continuity of the high peaks outside the threshold and the continuity at the threshold. The high peaks correspond to the NFC modulation signal. In the case of continuous high peaks at the filtering threshold, it indicates that the filtering threshold may cut off the NFC adjustment signal. If continuous modulation signals are distributed on both sides of the filtering threshold, the integrity of the NFC modulation signal is weaker. When there are more and more continuous high peaks within the filtering threshold compared to outside the filtering threshold, it means that there are more and more continuous modulation signal distributions within the filtering threshold, corresponding to a higher integrity of the NFC signal within the filtering threshold. Until there are no continuous high peaks outside the filtering threshold, the signal integrity within the threshold filtering reaches the highest.

[0055] Furthermore, the closer the distance between the left and right two high peaks closest to the left threshold and the distance between the left and right two high peaks closest to the right threshold are, the more likely it is that the initial filtering threshold is within the continuous signal segment, cutting off the NFC modulation signal, and the worse the integrity of the NFC modulation signal.

[0056] The blocking effect is obtained based on the distance between the left and right adjacent high peaks of the left threshold and the right threshold in the initial filtering threshold. Specifically, the sum of the distance between the two adjacent high peaks of the left threshold in the initial filtering threshold and the distance between the two adjacent high peaks of the right threshold is recorded as the blocking effect. The greater the blocking effect, the stronger the integrity of the NFC modulation signal. The smaller it is, the more likely there is a continuous high peak distribution in the initial filtering threshold, and the more likely the initial filtering threshold is to cut off the NFC modulation signal, and the worse the integrity of the cut-off NFC modulation signal.

[0057] Next, the continuity within the initial filtering threshold and outside the initial filtering threshold is analyzed. The range within the initial filtering threshold refers to the range between the left threshold and the right threshold. The continuity factor is obtained based on the peak difference between every two adjacent high peaks within the initial filtering threshold and outside the initial filtering threshold. Specifically, the average value of the absolute value of the peak difference between every two adjacent high peaks within the initial filtering threshold is obtained and inverted to get the continuity within the threshold; the average value of the absolute value of the peak difference between every two adjacent high peaks outside the initial filtering threshold is obtained and inverted to get the continuity outside the threshold; the ratio of the continuity within the threshold to the continuity outside the threshold is the continuity factor.

[0058] The specific calculation models for the continuity within the threshold and the continuity outside the threshold are as follows:

[0059] ,

[0060] ,

[0061] Among them, and respectively represent the degree of continuity within the threshold and the degree of continuity outside the threshold; and respectively represent the number of peaks within the initial filtering threshold and outside the initial filtering threshold. is the peak value (i.e., the signal intensity value) of the i-th peak in the horizontal axis direction within the initial filtering threshold. is the peak value of the peak after the i-th peak. represents the absolute value of the difference in peak values between two peaks. The smaller this value is, the lower the degree of change between the two peaks, the higher the degree of continuity, and the more gradual the continuity.

[0062] is the mean value of the cumulative sum of the differences in peak values of all peaks within the initial filtering threshold. The smaller this cumulative mean value is, the higher the degree of continuity of all peaks within the initial filtering threshold. Therefore, an inverse form is used ; is the mean value of the cumulative sum of the differences in peak values between peaks outside the initial filtering threshold. The larger this cumulative sum mean value is, the higher the degree of continuity of all peaks outside the initial filtering threshold. An inverse form is used ; is the ratio of the degree of continuity of peaks inside and outside the initial filtering threshold, that is, the continuity factor. The larger this ratio is, the stronger the degree of continuity of peaks within the initial filtering threshold compared to outside the initial filtering threshold. This value will reach the maximum when the initial filtering threshold blocks between the continuous NFC modulation signal and the discontinuous abnormal signal. At this time, the ratio is the largest.

[0063] Finally, by comprehensively considering the blocking effect and the continuity factor, the signal integrity of the NFC modulation signal when filtering using the initial filtering threshold can be obtained. The product of the blocking effect and the continuity factor is the signal integrity. The larger the signal integrity is, the better the filtering effect and the more complete the retained NFC modulation signal.

[0064] Step S4: Screen the peaks according to the peak value difference between each peak and its adjacent peak to obtain prominent peaks; obtain the degree of noise presence based on the number and prominence of prominent peaks within the initial filtering threshold; obtain the filtering effect of the initial filtering threshold based on the signal integrity and the degree of noise presence.

[0065] After analyzing the filtered signal completely, it is necessary to analyze the existence degree of the filtered noise. First, the signal peaks corresponding to Bluetooth signal interference are obtained according to the neighborhood distribution characteristics of the peaks. The neighborhood adjacent differences of all peaks are obtained. Since the NFC modulation signal is distributed in clusters and changes continuously and slowly, its peaks and adjacent data may both be peaks, and the adjacent differences are small. While the Bluetooth interference signal is discretely distributed and appears suddenly, and the differences between its peaks and adjacent data are large. Therefore, the differences between the two types of peaks are large. After linear normalization, two types of data can be obtained at both ends of the value range. Here, the median 0.5 can be taken as the segmentation threshold, and the peaks are divided according to the neighborhood distribution characteristic values. When the neighborhood distribution characteristic value is greater than the segmentation threshold, the peak is considered to be a peak with the characteristics of Bluetooth signal interference.

[0066] The peaks are screened according to the peak differences between each peak and the adjacent peaks to obtain the signal peaks. Specifically, the absolute values of the differences between the peak of a peak and the peaks of the two adjacent peaks on the left and right are calculated and summed respectively, and the result after summing is normalized to obtain the neighborhood distribution characteristic value of the peak. If the neighborhood distribution characteristic value of the peak is greater than the segmentation threshold, the peak is a signal peak. The calculation model of the neighborhood distribution characteristic value is:

[0067] ,

[0068] where, is the neighborhood distribution characteristic value of the p-th peak, is the peak value of the p-th peak, is the peak value of the peak before the p-th peak, is the peak value of the peak after the p-th peak, is the peak difference before and after the p-th peak. The greater this difference is, the greater the difference between the p-th peak and the adjacent peaks, and the more likely it is to be a signal peak. is the linear normalization. Thus, the signal peaks with neighborhood distribution characteristic values greater than 0.5 are obtained.

[0069] The existence degree of the noise signal is obtained from the difference degree between the signal peaks within the threshold and other peaks. Generally, the NFC main frequency signal occupies the main peak at 13.56 MHz. When the Bluetooth interference signal exists inside the continuous modulation signal of NFC, the Bluetooth interference signal will exist at the edges of the continuous NFC signals extending from the main peak to both sides. Therefore, the more signal peaks within the initial filtering threshold compared with other peaks and the greater the peak differences between the signal peaks and the adjacent peaks, it indicates that there are more signal peaks with the characteristics of Bluetooth interference signals within the threshold, and the more prominent the signal peaks represent the stronger the interference degree of the Bluetooth interference signal, then the more abnormal the data within the threshold is.

[0070] Obtain the degree of noise existence by using the number and prominence degree of spiky peaks within the initial filtering threshold. Specifically, calculate the sum of the absolute values of the differences between the peak value of a spiky peak and the peak values of the two adjacent peaks on the left and right, and denote it as the adjacent difference of this spiky peak; obtain the sum of the adjacent differences of all spiky peaks within the initial filtering threshold, and denote it as the prominence degree; multiply the number of spiky peaks within the initial filtering threshold by the prominence degree to obtain the degree of noise existence.

[0071] The calculation model of the degree of noise existence is specifically:

[0072] ,

[0073] where C represents the degree of noise existence corresponding to the initial filtering threshold, represents the number of spiky peaks within the initial filtering threshold. The more this number is, the stronger the degree of noise existence within the threshold; is the peak value of the i-th spiky peak among them, is the peak value difference between the i-th spiky peak and the adjacent peaks before and after, that is, the adjacent difference. The larger this adjacent difference is, the stronger the prominence degree of the corresponding i-th spiky peak. Relative to the adjacent NFC signal, the signal strength of this spiky peak is stronger, and the degree of interference to the NFC signal is stronger. Comprehensively accumulate the adjacent differences of all spiky peaks. The larger the cumulative sum is, the stronger the prominence degree of the spiky peaks within the threshold, and the stronger the degree of noise existence within the threshold.

[0074] Thus, comprehensively considering the above two evaluation features (signal integrity and degree of noise existence), the stronger the signal integrity of the NFC modulation signal and the lower the degree of noise existence, the better the filtering effect corresponding to the initial filtering threshold. Obtain the filtering effect of the initial filtering threshold according to the signal integrity and the degree of noise existence. Specifically, normalize the reciprocal of the degree of noise existence and the signal integrity respectively and then sum them to obtain the filtering effect of the initial filtering threshold. The purpose of normalization is to unify the magnitudes of the two evaluation features. Thus, an index for evaluating the filtering quality when performing band-pass filtering with different filtering thresholds can be obtained.

[0075] Step S5, update the initial filtering threshold to obtain an updated filtering threshold; select the updated filtering threshold with the maximum filtering effect for filtering.

[0076] In actual filtering, usually 2MHz around 13.56MHz can be taken as the maximum upper and lower thresholds. Thus, the initial filtering threshold is set to 13.56 ± 2MHz. Further, the initial filtering threshold is updated. Specifically, the update amplitude is set, and the left threshold and the right threshold in the initial filtering threshold are synchronously updated using the update amplitude to obtain the updated filtering threshold. Each update includes increasing the left threshold and decreasing the right threshold, and the increasing or decreasing amplitude is the update amplitude, and the update amplitude is 0.1MHz. The implementer can adjust according to the actual effect. After each update, the updated filtering threshold is used to filter the test signal and obtain the filtering effect. The updated filtering threshold with the maximum filtering effect is selected to filter the payment signal. Corresponding to this filtering threshold, the integrity of the NFC modulation signal is the strongest and the noise level is the lowest during the payment data interaction and transmission process. It can filter out the Bluetooth interference signal to the greatest extent while retaining the integrity of the NFC modulation signal.

[0077] In summary, traditional filtering usually uses a fixed filtering threshold to filter out the signals other than the NFC modulation signal in the payment signal. However, there will also be interference from Bluetooth signals at the inner edge of the continuous modulation signal of NFC. The traditional fixed threshold cannot filter out such interference. In this application, an evaluation model is constructed to evaluate the optimal threshold. The obtained filtering threshold comprehensively considers the signal integrity within the threshold and the severity of noise interference within the threshold. When the Bluetooth interference noise is strong within the NFC modulation signal, the obtained filtering threshold can contract inward for filtering. When the Bluetooth interference noise is weak within the NFC modulation signal, it can increase the threshold width to ensure the integrity of the NFC modulation signal.

[0078] When using the NFC payment ring to perform data interaction and transmission with the NFC terminal, the filtering threshold of the band-pass filter obtained in real time through the test signal is used to filter the transmitted payment signal, and the filtered payment signal is obtained as the actual transmitted data. It prevents the noise interference of the payment data transmission channel under the influence of the Bluetooth environment of the NFC payment ring, and better realizes the noise removal and the retention of the integrity of the original data during the payment signal transmission process.

[0079] It should be noted that: the above sequence of the embodiments of the present invention is only for description and does not represent the advantages or disadvantages of the embodiments. And the above specific embodiments of this specification have been described. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0080] Each embodiment in this specification is described in a progressive manner. The same or similar parts between each embodiment can be referred to each other, and the key points of each embodiment are the differences from other embodiments.

[0081] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A payment data interaction and transmission method for a smart terminal, characterized in that, The method includes: Converting the test signal received by the NFC payment ring into a spectrogram; obtaining the wave peaks in the spectrogram, screening out the high peaks, and obtaining the peak discreteness according to the distance between each high peak and the two adjacent high peaks on the left and right; Judging whether there is Bluetooth signal interference according to the peak discreteness; if there is Bluetooth signal interference, setting an initial filtering threshold for band-pass filtering; Obtaining the isolation effect according to the distance between the two adjacent high peaks on the left and right of the left threshold and the right threshold in the initial filtering threshold; obtaining the continuity factor according to the peak difference between every two adjacent high peaks within and outside the initial filtering threshold; multiplying the isolation effect and the continuity factor to obtain the signal integrity; Screening the high peaks according to the peak difference between each high peak and the adjacent high peaks to obtain the prominent peaks; obtaining the noise existence degree by using the number and prominence degree of the prominent peaks within the initial filtering threshold; obtaining the filtering effect of the initial filtering threshold according to the signal integrity and the noise existence degree; Updating the initial filtering threshold to obtain an updated filtering threshold; selecting the updated filtering threshold with the maximum filtering effect for filtering.

2. The payment data interaction and transmission method for an intelligent terminal according to claim 1, wherein The obtaining of the wave peaks in the spectrogram and screening out the high peaks includes: Using the AMPD peak search algorithm to obtain all the wave peaks in the spectrogram; normalizing the peak values of all the wave peaks to obtain the peak values of the normalized wave peaks; setting a screening threshold, when the threshold of the normalized wave peak is less than or equal to the screening threshold, the wave peak is a low peak, and when the threshold of the normalized wave peak is greater than the screening threshold, the wave peak is a high peak.

3. A payment data interaction and transmission method for a smart terminal according to claim 1, wherein, The obtaining of the peak discreteness according to the distance between each high peak and the two adjacent high peaks on the left and right includes: Obtaining the distances between each high peak in the spectrogram and the two adjacent high peaks on the left and right to form a distance set; calculating the variance of the distance set as the peak discreteness.

4. A payment data interaction and transmission method for a smart terminal according to claim 1, characterized in that, The judging whether there is Bluetooth signal interference according to the peak discreteness includes: Normalizing the peak discreteness, setting a first threshold, if the normalized peak discreteness is greater than or equal to the first threshold, there is Bluetooth signal interference.

5. A payment data interaction and transmission method for a smart terminal according to claim 1, characterized in that, The obtaining of the isolation effect includes: Obtaining the sum of the distances between the two adjacent high peaks on the left and right of the left threshold and the distances between the two adjacent high peaks on the left and right of the right threshold in the initial filtering threshold, denoted as the isolation effect.

6. The payment data interaction and transmission method for a smart terminal according to claim 1, characterized in that, The obtaining of the continuity factor according to the peak difference between every two adjacent high peaks within and outside the initial filtering threshold includes: Obtaining the average value of the absolute values of the peak differences between every two adjacent high peaks within the initial filtering threshold and taking the reciprocal to obtain the in-threshold continuity; obtaining the average value of the absolute values of the peak differences between every two adjacent high peaks outside the initial filtering threshold and taking the reciprocal to obtain the out-of-threshold continuity; the ratio of the in-threshold continuity to the out-of-threshold continuity is the continuity factor.

7. A payment data interaction and transmission method for a smart terminal according to claim 1, characterized in that, The screening of the high peaks according to the peak difference between each high peak and the adjacent high peaks to obtain the prominent peaks includes: Respectively calculating the sum of the absolute values of the differences between the peak of a high peak and the peaks of the two adjacent high peaks on the left and right, and normalizing the result after summation to obtain the neighborhood distribution characteristic value of the high peak; if the neighborhood distribution characteristic value of the high peak is greater than the segmentation threshold, the high peak is a prominent peak.

8. A payment data interaction and transmission method for a smart terminal according to claim 1, characterized in that, The obtaining of the noise existence degree by using the number and prominence degree of the internal peaks within the initial filtering threshold includes: Calculating the sum of the absolute values of the differences between the peak value of a peak and the peak values of the two adjacent peaks on the left and right, which is denoted as the adjacent difference of the peak; obtaining the sum of the adjacent differences of all the peaks within the initial filtering threshold, which is denoted as the prominence degree; multiplying the number of the peaks within the initial filtering threshold by the prominence degree to obtain the noise existence degree.

9. A payment data interaction and transmission method for a smart terminal according to claim 1, characterized in that, The obtaining of the filtering effect of the initial filtering threshold according to the signal integrity and the noise existence degree includes: Normalizing the reciprocal of the noise existence degree and the signal integrity respectively and then summing them to obtain the filtering effect of the initial filtering threshold.

10. A payment data interaction and transmission method for a smart terminal according to claim 1, characterized in that, The updating of the initial filtering threshold to obtain the updated filtering threshold includes: Setting an update amplitude, and synchronously updating the left threshold and the right threshold in the initial filtering threshold by using the update amplitude to obtain the updated filtering threshold; each update includes increasing the left threshold and decreasing the right threshold, and the increasing or decreasing amplitude is the update amplitude.

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