NFC simulation card automatic switching method, mobile terminal, program product and controller

Abstract

The invention provides an NFC simulation card automatic switching method, a mobile terminal, a program product and a controller. The provided NFC simulation card automatic switching method comprises the steps that when card equipment enters a radio frequency field of card reading equipment, channel fingerprint features of the card reading equipment are extracted; inputting the channel fingerprint features into a classification model; determining an application scene according to the output of the classification model; and selecting a target card corresponding to the determined application scene from the NFC simulation card.

Description

Technical Field

[0001] The present application relates to near field communication technology, and more specifically, to NFC analog card automatic switching technology. Background Art

[0002] Near Field Communication (NFC) is an emerging technology that allows devices (such as mobile terminals) using NFC to exchange data when they are close to each other.

[0003] Based on the convenience of NFC technology, a mobile terminal is usually equipped with multiple simulated card information that can communicate with trusted devices. In different scenarios, it is necessary to switch to the corresponding simulated card to complete NFC communication. The recognition of scenes is currently mainly through geographic location, screen status, somatosensory information, historical behavior data, etc. These methods have low accuracy in identifying target scenes, and are particularly difficult to deal with complex scenes or scenes with unstable geographic locations.

[0004] In addition, the above application layer-based identification is closer in time to the application selection stage in the protocol. Executing the relevant judgment logic at this time often requires changing the existing communication process, such as requiring users to wait for the judgment results, which has a certain impact on the user experience. Summary of the invention

[0005] According to some embodiments of the present application, an NFC simulated card automatic switching method is provided to solve at least one of the above problems.

[0006] The provided NFC simulated card automatic switching method includes extracting the channel fingerprint feature of the card reader device when the card device enters the radio frequency field of the card reader device; inputting the channel fingerprint feature into a classification model; determining an application scenario according to the output of the classification model; and selecting a target card corresponding to the determined application scenario from the simulated card.

[0007] According to the NFC simulated card automatic switching method of the embodiment of the present application, optionally, extracting the channel fingerprint characteristics of the card reader device includes: receiving a pilot signal sent by the card reader device; calculating the radio frequency channel characteristics of the card reader device according to the pilot signal; extracting the amplitude and phase of the channel characteristics from the radio frequency channel characteristics; and using the extracted amplitude and phase as the channel fingerprint characteristics of the card reader device.

[0008] According to the NFC analog card automatic switching method of the embodiment of the present application, optionally, calculating the radio frequency channel characteristic information of the card reader device according to the pilot signal includes calculating the radio frequency channel characteristic of the card reader device by the following formula:

[0009] Y=S*H

[0010] Wherein, Y represents the signal sent by the card reader device and received by the card device; S represents the leading signal; and H represents the channel characteristics of the transmission channel between the card reader device and the card device.

[0011] Extracting the amplitude and phase of the channel characteristic from the radio frequency channel characteristic includes determining the amplitude and phase of the channel characteristic according to the following formula:

[0012]

[0013] Among them, h2 represents the channel characteristics of the card device; h0 represents the channel characteristics of the card reader device; A0 represents the amplitude of the radio frequency channel characteristics; θ0 represents the phase of the radio frequency channel characteristics.

[0014] According to the NFC simulated card automatic switching method of the embodiment of the present application, optionally, the classification label of the classification model is set based on the production factors of the card reading device.

[0015] According to the NFC simulated card automatic switching method of the embodiment of the present application, optionally, a target card corresponding to the determined application scenario is selected from the NFC simulated card, including obtaining the current application scenario of the NFC simulated card of the card device by the NFC management application of the card device; comparing the determined application scenario with the acquired current application scenario; when the comparison results are consistent, no switching is required; when the comparison results are inconsistent, switching from the current simulated card used for the current application scenario to the target card; wherein the current application scenario is the application scenario of the card device when it was swiped the card last time or is a set default application scenario.

[0016] According to some other embodiments of the present application, a mobile terminal is provided, which includes a memory for storing instructions and a processor for executing the instructions and implementing any one of the NFC simulated card automatic switching methods described herein when executing the instructions.

[0017] According to some other embodiments of the present application, a program product is provided, wherein the program product includes instructions, and when the instructions are executed, any one of the NFC simulated card automatic switching methods described herein is implemented.

[0018] According to some other embodiments of the present application, a non-transitory storage medium is provided, on which instructions are stored, and when the instructions are executed, any one of the NFC simulated card automatic switching methods described herein is implemented.

[0019] According to some further embodiments of the present application, an NFC controller is provided, wherein the controller is configured to execute program instructions for implementing any one of the NFC emulated card automatic switching methods described herein.

[0020] In the above examples, the mobile terminal is, for example, a mobile phone, a tablet, a smart wearable device, a laptop computer, etc., wherein the smart wearable device is, for example, a smart bracelet, a smart watch, smart glasses, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The following will describe the embodiments of the present application in detail with reference to the accompanying drawings so that the present application can be more fully understood, wherein:

[0022] Figure 1 is an exemplary diagram of an NFC emulated card application environment diagram;

[0023] Figure 2 is a flowchart of an NFC simulated card automatic switching method according to some embodiments of the present application;

[0024] Figure 3 is a flowchart of an NFC simulated card automatic switching method according to some other embodiments of the present application;

[0025] Figure 4 is a schematic diagram of a signal transmission path according to some embodiments of the present application;

[0026] Figure 5 It is a schematic diagram of the structure of the mobile terminal 5 according to some embodiments of the present application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the following will be combined with the accompanying drawings to describe the implementation methods of the present application more clearly and completely. It should be noted that the described implementation methods are only partial implementation methods of the technical solutions of the present application, not all. All other implementation methods obtained by ordinary technicians in this field based on the implementation methods recorded in the application documents without paying creative work are covered by the protection scope of the present application.

[0028] Figure 1 is an exemplary diagram of an application environment diagram of an NFC emulated card. Figure 1 As shown, when the mobile terminal 20 provided with an NFC simulated card is in the radio frequency field of the card reader 10, it communicates with the card reader 10 to select a card suitable for the current application scenario from multiple NFC simulated cards set in the mobile terminal 20 and swipe the card.

[0029] Application scenarios include access control card swiping, public transportation card swiping, life service card swiping (such as water, electricity, gas cards), etc. Different application scenarios correspond to different NFC analog cards.

[0030] Figure 2 This is a flowchart of an NFC simulated card automatic switching method according to some embodiments of the present application. Figure 2 The method of the illustrated example includes step S200 , step S202 , step S204 , and step S206 .

[0031] In step S200, when the card device enters the radio frequency field of the card reader device, the channel fingerprint feature of the card reader device is extracted.

[0032] Examples of card devices include, but are not limited to, mobile terminals. Mobile terminals include, for example, mobile phones, tablets, smart wearable devices, laptops, etc., wherein smart wearable devices include, for example, smart bracelets, smart watches, smart glasses, etc. Card devices can be various electronic devices that are equipped with NFC analog cards and can interact with NFC card readers. The card devices listed in the examples of this application are only examples and are not exhaustive.

[0033] During the manufacturing process of NFC card reader devices, affected by factors such as material properties, processing technology, and assembly errors, the signal behavior of each manufactured NFC card reader device at the physical layer has unique channel characteristics. This channel characteristic appears after the hardware processing of the NFC card reader device is completed, and does not change significantly over time, that is, this channel characteristic is relatively constant. The embodiments of the present application use this characteristic of the radio frequency signal to identify different NFC devices, and then identify the usage scenario of the NFC device.

[0034] According to this example, when the card device enters the radio frequency field of the card reader device, the card device receives the leading signal sent by the card reader device. The card device calculates the radio frequency channel characteristics of the card reader device based on the information carried by the leading signal. For example, the card device extracts the amplitude and phase information of the radio frequency channel characteristics, and uses the two as the channel fingerprint characteristics of the card reader device. It should be noted that in some other examples, one of the amplitude and phase information of the extracted radio frequency channel characteristics can be considered as the channel fingerprint characteristics of the card reader device. In other examples, other parameters other than the amplitude and phase information of the radio frequency channel characteristics can also be considered as channel fingerprint characteristics.

[0035] In step S202, the channel fingerprint feature is input into the classification model.

[0036] The classification model is a model that is pre-trained and set in the card device. According to this embodiment, the classification model is pre-trained. During the training process, data indicating the manufacturer of the card reader device, the production batch of the card reader device, the usage scenario of the card reader device, etc. can be used as training data for the classification model. Specifically, these data are used as category labels to classify the channel fingerprint features of the card reader device. The classification model can be based on algorithms such as support vector machines (SVM).

[0037] In step S204, the application scenario is determined according to the output of the classification model.

[0038] After receiving the input channel fingerprint feature, the classification model determines the category information of the channel fingerprint feature, and determines the application scenario of the card reading device according to the category information.

[0039] In step S206, a target card corresponding to the determined application scenario is selected from a plurality of NFC simulation cards arranged in the card device, that is, a card suitable for the determined application scenario is selected.

[0040] In this embodiment, the card device selects a target card corresponding to the determined application scenario from the NFC simulated card according to the determined application scenario information, thereby realizing automatic card switching and completing card swiping with the switched card. For example, if the determined application scenario is access control, the card device calls the identification card for the access control from the NFC simulated card to complete access control card swiping identification.

[0041] Compared with the situation when users need to manually select a card suitable for a specific application scenario on the card device when swiping an NFC simulated card, according to the method of the example of this application, the card device can determine the application scenario where the card reader device is located based on the channel fingerprint characteristics, and select a simulated card for the application scenario from multiple NFC simulated cards. In this process, users do not need to manually select a suitable card from multiple simulated cards, but the card device automatically selects the NFC simulated card, which improves the user experience, and because the entire process eliminates the need for manual selection and other operations, it also saves time and improves the efficiency of card swiping.

[0042] Figure 3 is a flow chart of an NFC simulated card automatic switching method according to some other embodiments of the present application. By way of example and not limitation, Figure 3 The method shown in Figure 1 The following description is given in the application environment shown in the figure.

[0043] In step S300 , when the mobile terminal 20 enters the radio frequency field of the card reader 10 , it receives a leading signal sent by the card reader 10 .

[0044] According to the basic principle of communication, assuming that the leading signal sent by the transmitter is S and the signal received by the receiver is Y, the signal transmission process can be expressed by formula (1):

[0045] Y=S*H (1)

[0046] Among them, H represents the channel characteristics of the transmission channel, the pilot signal S is a pilot signal used for synchronization in the existing communication protocol, and the value of S is known in advance between the signal transmitter and the signal receiver based on the protocol. As an example, Y, S and H are all vector data.

[0047] like Figure 4As shown, according to the signal propagation path, the transmission channel in this embodiment can be further decomposed into three parts: radio frequency (RF) signal transmitting end, intermediate transmission and RF signal receiving end. Therefore, H can be further refined and expressed as formula (2):

[0048] H=h0*h1*h2 (2)

[0049] in, j is 0 or 1 or 2, h0, h1 and h2 are the channel characteristics of the RF signal transmitting end, the RF signal intermediate transmission and the RF signal receiving end respectively; wherein, h0 is determined by the RF characteristics of the transmitting device as the signal transmitting end, and h2 is determined by the RF characteristics of the receiving device as the signal receiving end. Here, the RF characteristics of each device can be obtained by channel correction or equivalent channel method. In this embodiment, the signal transmitting device can be a card reading device 10, and the receiving device can be a mobile terminal 20 carrying an NFC simulated card. Due to the short-range characteristics of NFC, when swiping the card, the terminal 20 is often required to be attached to the card reading device 10, so the signal is less affected and the changes produced during the intermediate transmission process are small, h1 can be approximated to 1, so H can be approximately expressed as formula (3):

[0050]

[0051] The mobile terminal 20 as the signal receiving end knows its channel characteristic h2. Based on this, the mobile terminal 20 can obtain the channel characteristic h0 of the card reader device as the RF signal transmitting end through formula (3). As mentioned above, h0 is determined by the hardware of the signal transmitting end. When the device as the signal transmitting end is manufactured, the channel characteristic is determined, so it is called the channel fingerprint here.

[0052] In step S302, the mobile terminal 20 calculates the radio frequency channel characteristics of the card reader device 10 according to the pilot signal. Specifically, the channel characteristics of the transmission channel between the card reader device and the card device can be calculated by formula (1), that is, the mobile terminal 20 calculates the channel characteristics H of the transmission channel between the card reader device 10 and the mobile terminal 20 according to the pilot signal S sent by the card reader device 10.

[0053] In step S304, the mobile terminal 20 extracts the amplitude and phase of the channel characteristics from the RF channel characteristics. Specifically, the mobile terminal 20 calculates the channel characteristics of the card device according to formula (3). It can be understood that for the mobile terminal 20 as a card reader, h2 representing the channel characteristics of the card reader is known. Therefore, when the channel characteristics H is calculated according to formula (1) and h2 is known, h0 can be calculated by formula (3). Then, the amplitude A0 representing the RF channel characteristics and the phase θ0 representing the RF channel characteristics are determined according to the following formula (4):

[0054]

[0055] For example, when h0 is equivalent to a complex number, the real part of h0 can be taken as the amplitude A0 and the imaginary part can be taken as the phase θ0.

[0056] In step S306, the mobile terminal 20 uses the determined amplitude A0 and phase θ0 as the channel fingerprint characteristics of the card reader 10, thereby identifying the application scenario of the card reader 10. For example, the mobile terminal 20 identifies the card reader 10 as a subway gate according to the channel fingerprint characteristics.

[0057] In step S308, the NFC management application of the mobile terminal 20 obtains the current application scenario of the NFC simulated card in the mobile terminal 20. The current application scenario refers to the application scenario corresponding to the card currently presented in the NFC simulated card of the mobile terminal 20. As an example, the currently presented card may be the card used by the mobile terminal 20 when swiping the card last time. For example, the card currently presented by the mobile terminal is a subway card, and the current application scenario of the mobile terminal 20 is a subway gate. Alternatively, the currently presented card may be a default card set, and the current application scenario is also the default setting.

[0058] In step S310, the mobile terminal 20 compares the determined application scenario with the acquired current application scenario. If the comparison result is consistent, the process proceeds to step S312, otherwise, the process proceeds to step S314.

[0059] In step S312, no switching is required. That is, the current application scenario of the NFC simulated card of the mobile terminal 20 is consistent with the determined one, and the current card in the NFC simulated card of the mobile terminal 20 can be directly used to interact with the card reader to complete the card swiping operation.

[0060] In step S314, the current application scenario of the NFC simulated card of the mobile terminal 20 is inconsistent with the determined application scenario. Therefore, the mobile terminal 20 switches the current card in the NFC simulated card to the target card to adapt to the determined application scenario, thereby completing the card swiping operation.

[0061] Figure 5 1 is a schematic diagram of the structure of a mobile terminal 5 according to an example of the present application. The mobile terminal 5 includes a memory 50 and a processor 52. The memory 50 stores instructions, and the processor 52 executes the instructions and implements any one of the NFC simulated card automatic switching methods described above when executing the instructions. The mobile terminal 5 can be implemented as the mobile terminal 20 described above in conjunction with the accompanying drawings, for example.

[0062] According to an example of the present application, a controller is also provided, which is configured to execute any one of the NFC analog card automatic switching methods described above. The controller may be, for example, a processor, and any one of the NFC analog card automatic switching methods described above may be implemented by setting executable program instructions in the processor. The controller may be, for example, set in the mobile terminal 20 or the mobile terminal 5.

[0063] According to an example of the present application, a non-transitory storage medium is also provided, on which instructions are stored, and when the instructions are executed, any one of the NFC simulated card automatic switching methods described above is implemented.

[0064] According to an example of the present application, a program product is also provided, the program product comprising instructions, the instructions implementing any one of the NFC simulated card automatic switching methods described above when executed. The program product is, for example, an NFC management program.

[0065] Although specific embodiments of the present application have been shown and described in detail to illustrate the principles of the present application, it should be understood that the present application may be implemented in other ways without departing from such principles, for example, the technical features of the various embodiments / examples / examples of the present application may be combined with each other to form new implementation methods.

Claims

1. A method for automatically switching NFC simulated cards, characterized in that: The method comprises: When the card device enters the radio frequency field of the card reader device, extracting the channel fingerprint feature of the card reader device; Inputting the channel fingerprint feature into a classification model; Determining an application scenario based on the output of the classification model; A target card corresponding to the determined application scenario is selected from the NFC simulated cards.

2. The method according to claim 1, characterized in that: Extracting the channel fingerprint feature of the card reader device includes: Receiving a leading signal sent by the card reading device; Calculate the radio frequency channel characteristics of the card reader device according to the pilot signal; Extracting the amplitude and phase of a channel characteristic from the radio frequency channel characteristic; The extracted amplitude and phase are used as channel fingerprint features of the card reading device.

3. The method according to claim 2, characterized in that Calculating the radio frequency channel characteristic information of the card reader device according to the pilot signal includes: The radio frequency channel characteristics of the card reader are calculated by the following formula: Y=S*H Wherein, Y represents the signal sent by the card reader device and received by the card device; S represents the pilot signal; and H represents the radio frequency channel characteristics of the transmission channel between the card reader device and the card device.

4. The method according to claim 3, characterized in that Extracting the amplitude and phase of the channel characteristic from the radio frequency channel characteristic, comprising: The amplitude and phase of the channel characteristic are determined according to the following formula: Among them, h2 represents the channel characteristics of the card device; h0 represents the channel characteristics of the card reader device; A0 represents the amplitude of the radio frequency channel characteristics; θ0 represents the phase of the radio frequency channel characteristics.

5. The method according to claim 1, characterized in that The classification labels of the classification model are set based on production factors of the card reading device.

6. The method according to claim 1, characterized in that Selecting a target card corresponding to the determined application scenario from the NFC simulated cards includes: The NFC management application of the card device obtains the current application scenario of the NFC simulated card in the card device; comparing the determined application scenario with the acquired current application scenario; If the comparison results are consistent, there is no need to switch; If the comparison results are inconsistent, switching from the current simulation card used for the current application scenario to the target card; The current application scenario is the application scenario of the card device when the card was swiped last time or is a set default application scenario.

7. The method according to any one of claims 1 to 6, characterized in that The card device is a mobile terminal.

8. A mobile terminal, characterized in that: The mobile terminal comprises: A memory for storing instructions; A processor is used to execute the instruction and implement the NFC simulated card automatic switching method according to any one of claims 1 to claim 6 when executing the instruction.

9. A program product, characterized in that The program product includes instructions, which, when executed, implement the NFC simulated card automatic switching method according to any one of claims 1 to 6.

10. An NFC controller, characterized in that: The controller is configured to execute program instructions for implementing the NFC emulation card automatic switching method according to any one of claims 1 to 6.

11. A non-transitory storage medium, characterized in that: The storage medium stores instructions, which, when executed, implement the NFC simulated card automatic switching method according to any one of claims 1 to 6.

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