Method for estimation and tracking of interfering signals in wi-fi networks and communication device

Abstract

The application provides a method for estimating and tracking interference signals in a Wi-Fi network and a communication device. The method for estimating and tracking interference signals in a Wi-Fi network comprises the following steps: S1, receiving an analog wireless signal to be evaluated; S2, performing analog-to-digital conversion on the analog wireless signal to be evaluated to obtain a digital signal; S3, converting the digital signal into a frequency domain signal; and S4, calculating an interference observation value at a current moment according to the power of each subcarrier in the frequency domain signal.

Description

Technical Field

[0001] This application relates primarily to the field of communication technology, and in particular to a method and communication device for estimating and tracking interference signals in Wi-Fi networks. Background Technology

[0002] Wi-Fi technology, as one of the most widely used local area communication technologies in the current wireless communication field, covers various communication scenarios such as smart homes, smart offices, and mobile IoT. Wi-Fi mainly operates in three frequency bands: 2.4GHz, 5GHz, and 6GHz. Among them, 2.4GHz and 5GHz are public and open frequency bands, which can be used freely without applying for a license from a radio management agency. However, Wi-Fi operating frequency bands are often occupied by other wireless communication devices such as Bluetooth, leading to significant interference. This interference affects the transmission efficiency and stability of Wi-Fi signals, reducing the communication performance of the Wi-Fi system.

[0003] Current mainstream anti-interference solutions mostly rely on fixed interference avoidance rules or preset feature templates for common interference signals (such as Bluetooth and radar). After matching the characteristics of the interference signal at the receiving end, interference cancellation is performed, which is difficult to adapt to the dynamic changes of interference in public open frequency bands. In addition, the time-frequency characteristics of frequency hopping signals such as Bluetooth will dynamically change, which can easily lead to problems such as feature matching failure, misidentification, and missed identification, thus reducing the anti-interference effect.

[0004] Therefore, there is an urgent need in the field for a method and communication device for estimating and tracking interference signals in Wi-Fi networks, which can effectively estimate the interference situation in the Wi-Fi operating frequency band and continuously track changes in the interference situation, providing a reliable basis for interference avoidance and interference elimination, thereby improving the anti-interference performance of Wi-Fi networks. Summary of the Invention

[0005] The technical problem to be solved by this application is to provide a method and communication device for estimating and tracking interference signals in Wi-Fi networks. It can effectively estimate the interference situation in the Wi-Fi operating frequency band and continuously track the changes in the interference situation, providing a reliable decision basis for interference avoidance and interference elimination, thereby improving the anti-interference performance of Wi-Fi networks.

[0006] To address the aforementioned technical problems, this application provides a method for estimating and tracking interference signals in a Wi-Fi network, comprising: S1: receiving an analog wireless signal to be evaluated; S2: performing analog-to-digital conversion on the analog wireless signal to be evaluated to obtain a digital signal; S3: converting the digital signal into a frequency domain signal; S4: calculating the interference observation value at the current moment based on the power of each subcarrier in the frequency domain signal; wherein, S1 to S4 are performed within a frame interval.

[0007] This application also provides a communication device, including: a plurality of modems; a plurality of processors communicatively connected to the plurality of modems; and a plurality of memories communicatively connected to the plurality of processors and storing executable code, wherein when the plurality of processors cooperate with the plurality of modems to execute the executable code, the executable code is configured to execute the estimation and tracking method for interference signals in a Wi-Fi network as described above.

[0008] Compared with the prior art, this application has the following advantages: (1) By receiving the analog wireless signal to be evaluated within the frame interval, the normal transmission of the working signal is avoided, and the working signal is not misidentified as an interference signal, thereby improving the accuracy of interference signal estimation and the transmission stability of Wi-Fi signal. (2) By calculating the interference observation value at the current moment in each frame interval, the interference situation of the channel is continuously tracked, thereby updating the interference estimation result at the current moment in real time and improving the real-time performance and accuracy of the interference signal estimation result. Attached Figure Description

[0009] The accompanying drawings are included to provide a further understanding of this application; they are incorporated into and constitute a part of this application. The drawings illustrate embodiments of this application and, together with this specification, serve to explain the principles of this application. In the drawings: Figure 1 This is the basic timing diagram of the Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA) mechanism; Figure 2 This is a flowchart illustrating a method for estimating and tracking interference signals in a Wi-Fi network according to an embodiment of this application; Figure 3 This is a schematic diagram of the process of simulating wireless signal conversion to be evaluated in one embodiment of this application; Figure 4 This is a schematic diagram of the analog-to-digital conversion process in one embodiment of this application; Figure 5 This is a schematic diagram of the structure of a communication device according to an embodiment of this application.

[0010] Reference numerals: communication device 300, modem 310, processor 320, memory 330, antenna 340. Detailed Implementation

[0011] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some examples or embodiments of this application. For those skilled in the art, these drawings can be applied to other similar scenarios without creative effort. Unless obvious from the context or otherwise specified, the same reference numerals in the drawings represent the same structures or operations.

[0012] As indicated in this application and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" are not specifically singular and may include plural forms. Generally speaking, the terms "comprising" and "including" only indicate the inclusion of explicitly identified steps and elements, which do not constitute an exclusive list, and the method or apparatus may also include other steps or elements.

[0013] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0014] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. In addition, although the terminology used in this application is selected from commonly known and used terms, some terms mentioned in this application's specification may have been chosen by the applicant according to his or her judgment, and their detailed meanings are explained in the relevant sections of this description. Moreover, this application should be understood not only through the actual terms used, but also through the meaning implied by each term.

[0015] It should be understood that when a component is referred to as "on another component," "connected to another component," "coupled to another component," or "in contact with another component," it can be directly on, connected to, coupled to, or in contact with that other component, or there may be an intervening component. In contrast, when a component is referred to as "directly on another component," "directly connected to," "directly coupled to," or "directly in contact with" another component, there is no intervening component. Similarly, when a first component is referred to as "electrically contacting" or "electrically coupled to" a second component, there is an electrical path between the first and second components that allows current to flow. This electrical path may include capacitors, coupled inductors, and / or other components that allow current to flow, even if there is no direct contact between the conductive components.

[0016] Flowcharts are used in this application to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, various steps can be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more steps may be removed from these processes.

[0017] refer to Figure 1 The diagram shown is a basic timing diagram of the Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA) mechanism. This diagram is used to illustrate the technical solution of the method for estimating and tracking interference signals in Wi-Fi networks in this application.

[0018] Carrier Sense Multiple Access (CSMA) / Collision Avoidance (CSAD) mechanisms mitigate channel collisions caused by multiple communication devices simultaneously transmitting signals through channel sensing, frame interval waiting, and backoff window mechanisms. For example... Figure 1 As shown, "media busy" indicates that during this period, communication devices are occupying the channel to send data frames. After other communication devices detect that the channel is idle, they must wait at least one frame interval before they can seize the channel to send the next data frame.

[0019] The Wi-Fi protocol defines three frame intervals: Short Inter-Frame Space (SIFS), Priority Inter-Frame Space (PIFS), and Distributed Coordination Function Inter-Frame Space (DIFS). The Short Inter-Frame Space is the shortest in duration; during it, no communication device is allowed to send data frames. A communication device must wait at least one Short Inter-Frame Space before sending a frame exchange sequence that cannot be interrupted by other devices to ensure the integrity of the communication process. The Priority Inter-Frame Space is longer than the Short Inter-Frame Space; a communication device must wait at least one Priority Inter-Frame Space before sending a contention-free, priority-transmitted data frame. The Distributed Inter-Frame Space is the longest of both the Short and Priority Inter-Frame Spaces; a communication device must wait at least one Distributed Inter-Frame Space before initiating a new, independent data frame transmission.

[0020] The Physical Layer Protocol Data Unit (PPDU) is the transmission unit of the Wi-Fi protocol. In Wi-Fi communication standards such as IEEE 802.11ax and IEEE 802.11n MIMO, the PPDU includes a Packet Extension (PE). Upon completion of receiving the PE, the channel is considered to be in an idle state. The PE artificially extends the transmission time of the PPDU to provide sufficient frame processing buffer time for the receiving wireless signal communication device. Both the PE and the frame interval serve to avoid collisions.

[0021] The method for estimating and tracking interference signals in Wi-Fi networks disclosed in this application improves the accuracy of interference signal estimation results by performing interference signal estimation and tracking within frame intervals, thereby avoiding interference with the normal transmission of the working signal and preventing the working signal from being misidentified as an interference signal. The method will now be described using specific embodiments.

[0022] refer to Figure 2 A flowchart illustrating a method for estimating and tracking interference signals in a Wi-Fi network, as shown in one embodiment, and... Figure 3 The illustrated embodiment shows a flowchart of the analog wireless signal conversion process to be evaluated, including methods for estimating and tracking interference signals. Figure 2 Steps S1 to S4 in the process are performed within the frame interval. Next, combined with... Figure 2 and Figure 3 Detailed explanation of steps S1 to S4.

[0023] In step S1, the simulated wireless signal to be evaluated is received.

[0024] In specific implementation, after receiving a frame of data and when the channel is idle, the wireless signal on the channel is collected as the simulated wireless signal to be evaluated. Further, in some embodiments, the physical layer protocol data unit includes a packet extension field; after receiving the packet extension field and when the channel is idle, the wireless signal on the channel is collected as the simulated wireless signal to be evaluated.

[0025] In other embodiments, the simulated wireless signal to be evaluated is received after a preset time elapsed from the start point of the frame interval. Specifically, the start point of the frame interval is the moment when all bits of the previous physical layer protocol data unit have been received, at which point the channel occupancy state switches from "busy state" to "idle state". After the preset time elapsed from the start point of the frame interval, while the channel is still in an idle state, the simulated wireless signal to be evaluated is received, thereby acquiring the simulated wireless signal in the absence of a working signal, thus reducing the influence of the working signal on the simulated wireless signal to be evaluated.

[0026] Furthermore, in some embodiments, the preset duration is less than the length of the frame interval and greater than the fall time of the previous frame of the frame interval.

[0027] Specifically, the frame interval length refers to the time between the completion of receiving all bits of the previous frame and the start of transmitting the first bit of the next frame. A preset duration shorter than the frame interval length ensures that the simulated wireless signal to be evaluated is received when the channel is idle, thus avoiding misidentification of the working signal as interference.

[0028] The fall time of the preceding frame in the frame interval refers to the time it takes for the transmit power of the communication device transmitting that frame to decrease from one percentage (e.g., 90%) of its maximum transmit power to another percentage (e.g., 10%). Setting a fall time longer than the preceding frame's fall time in the frame interval helps reduce the impact of the operating signal on the analog wireless signal being evaluated, thereby improving the accuracy of interference estimation based on the analog wireless signal. It is understood that the fall time is related to the physical layer performance indicators of the communication device and is not limited by the timing position of the frame; the above description is merely an illustrative explanation adapted to the frame interval.

[0029] In step S2, the analog wireless signal to be evaluated is converted from analog to digital to obtain a digital signal.

[0030] Specifically, the analog wireless signal to be evaluated is sampled according to a fixed sampling step size, that is, the instantaneous value of the analog wireless signal to be evaluated is collected once every sampling step size, and a digital signal is obtained through quantization, encoding and reprocessing. Analog-to-digital conversion converts the temporally continuous analog wireless signal to be evaluated into a temporally discrete digital signal, which is used in subsequent steps S3 to S4 for interference signal estimation.

[0031] refer to Figure 4 The schematic diagram of the analog-to-digital conversion process in one embodiment shown below further includes steps S21 to S22 in step S2. The following will be combined with... Figure 3 and Figure 4 Detailed explanation of steps S21 to S22.

[0032] In step S21, the analog wireless signal to be evaluated is converted from analog to digital to obtain an initial digital signal.

[0033] In specific implementation, such as Figure 3 As shown, the analog wireless signal to be evaluated is down-frequency processed by a radio frequency (RF) circuit to convert it into a baseband analog signal (also known as a zero-frequency analog signal). Subsequently, the baseband analog signal is sampled by an ADC (Analog to Digital Converter), acquiring instantaneous values ​​of the baseband analog signal at a fixed sampling step size to convert it into an initial digital signal. The ADC sampling rate satisfies the Nyquist criterion, meaning the sampling rate is greater than twice the bandwidth of the baseband analog signal to avoid distortion of the initial digital signal. For the specific implementation details of the RF circuit and ADC sampling, please refer to relevant technologies; they will not be elaborated upon here.

[0034] In step S22, the initial digital signal is downsampled to reduce the sampling rate and obtain a digital signal, wherein the sampling rate of the digital signal is at least twice the operating bandwidth of the analog wireless signal to be evaluated.

[0035] In practice, a digital front-end (DFE) preprocesses and downsamples the initial high-data-rate digital signal to obtain a digital signal for interference signal estimation. When the sampling rate of the digital signal is twice the operating bandwidth of the analog wireless signal being evaluated, in-band interference can be observed through the digital signal; when the sampling rate of the digital signal is twice or more the operating bandwidth of the analog wireless signal being evaluated, out-of-band interference can be observed through the digital signal.

[0036] For example, such as Figure 3As shown, the sampling rate is set to twice the operating bandwidth of the analog wireless signal to be evaluated. A digital signal with twice the operating bandwidth is obtained by DFE downsampling and the digital signal is buffered in the first buffer.

[0037] Continue to refer to Figure 2 In step S3, the digital signal is converted into a frequency domain signal.

[0038] Specifically, time-frequency conversion is performed on the digital signal, decomposing the time-series digital signal into a superposition of sine / cosine components of different frequencies, thereby converting the digital signal into a frequency domain signal composed of discrete frequency points with the same sequence length as the digital signal.

[0039] In some embodiments, step S3 includes performing a Fast Fourier Transform (FFT) on the stored digital signal when the number of points in the stored digital signal reaches a preset number of points, to obtain a frequency domain signal. Here, the number of points in the digital signal refers to the number of sampled values ​​included in the stored digital signal.

[0040] In further embodiments, such as Figure 3 As shown, when the number of points of the digital signal buffered in the first buffer reaches twice the number of Fast Fourier Transform (Nfft) points, the digital signal buffered in the first buffer is subjected to FFT processing to obtain the frequency domain signal.

[0041] In step S4, the interference observation value at the current moment is calculated based on the power of each subcarrier in the frequency domain signal.

[0042] For example, such as Figure 3 As shown, the frequency domain signal buffered in the first buffer is ,in, The frequency points of the frequency domain signal correspond to the subcarriers of the simulated wireless signal being evaluated. The number of frequency points in the frequency domain signal is twice the number of points in the Fast Fourier Transform. By calculating the power of each point in the frequency domain signal, the power of each subcarrier is obtained. The power of each subcarrier is the interference observation value at the current moment.

[0043] As an example, the formula for calculating the power of each point in a frequency domain signal is:

[0044] In the formula, for Interference observations at frequency points For frequency domain signals in In-phase components at frequency points, For frequency domain signals in Orthogonal components of the frequency points. The number of points in the frequency domain signal corresponds to the number of subcarriers of the analog wireless signal being evaluated.

[0045] The method for estimating and tracking interference signals in Wi-Fi networks disclosed in this application continuously tracks channel interference by calculating the current interference observation value within each frame interval. This is particularly useful for devices employing frequency-hopping transmission technology, such as Bluetooth, where obtaining short-term channel interference data makes it difficult to identify Bluetooth interference signals. By continuously tracking channel interference over multiple frame intervals, the accuracy of interference estimation results for devices using frequency-hopping transmission technology can be improved.

[0046] As another embodiment of the method for estimating and tracking interference signals in Wi-Fi networks according to this application, in addition to steps S1 to S4 described above, step S5 is also included.

[0047] In step S5, based on the current interference observation value and the stored interference estimation result from the previous time, the interference is recursively estimated by filtering to obtain the interference estimation result for the current time.

[0048] In some embodiments, such as Figure 3 As shown, Kalman filtering is applied to the current interference observation and the previous interference estimation result stored in the second buffer to obtain the interference estimation result at the current time.

[0049] Thus, by using Kalman filtering to form a recursive estimate of the interference, the interference estimation result at each time step is obtained by combining the interference observation value at the current time step with the interference estimation result at the previous time step, thereby improving the real-time performance and accuracy of the interference estimation result.

[0050] Furthermore, in some embodiments, the interference estimation result obtained by filtering at the current moment is stored in a second buffer, so that the interference estimation value of the previous moment stored in the second buffer is updated to the interference estimation value of the current moment.

[0051] As an example, the Kalman filter formula is:

[0052] In the formula, for The interference estimate for the current frequency point. for The current interference observation value at the frequency point. for Interference estimate of the frequency point at the previous moment, These are the filter coefficients. For example, the filter coefficients are determined based on the specific circumstances, for instance, Take 0.1.

[0053] In some embodiments, steps S1 to S4 of the method for estimating and tracking interference signals in a Wi-Fi network according to this application are performed within a short frame interval (SIFS). During the SIFS, no communication device is allowed to transmit data frames, thus reducing the influence of the operating signal on the interference observation at the current moment, thereby improving the accuracy of the interference signal estimation. Furthermore, in other embodiments, other steps in the estimation and tracking method are also performed within the SIFS.

[0054] In other embodiments, after obtaining the interference estimation result at the current moment, the anti-interference capability of the Wi-Fi network is improved by applying interference avoidance algorithms or interference cancellation algorithms. For example, it is determined whether the power of each subcarrier is greater than a threshold. If the power is greater than the threshold, then there is an interference signal on that subcarrier. The subcarrier transmitting the Wi-Fi signal is switched using an interference avoidance algorithm, or the Wi-Fi signal on that subcarrier is obtained using an interference cancellation algorithm, so as to improve the transmission stability of the Wi-Fi signal.

[0055] This application also proposes a communication device, see reference. Figure 5 A schematic diagram of the communication device in one embodiment is shown. Figure 5 As shown, the communication device 300 includes a plurality of modems 310, a plurality of processors 320 communicatively connected to the plurality of modems 310, and a plurality of memories 330 communicatively connected to the plurality of processors 320 and storing executable code. Figure 5 Only one modem 310, one processor 320 and one memory 330 are shown for illustration purposes. It can be understood that the communication device 300 may include multiple of the above-mentioned components.

[0056] like Figure 5 As shown, the communication device 300 also includes an antenna 340 electrically connected to the modem. During the frame interval, when the communication device 300 detects that the channel is idle, the antenna 340 receives the analog wireless signal to be evaluated. When the processor 320, in conjunction with the modem 310, executes executable code, the executable code is configured to: execute as follows... Figure 2 The steps S1 to S4 shown are for estimating and tracking the interference signal. The executable code can also be configured to perform other method steps described above, excluding steps S1 to S4.

[0057] The basic concepts have been described above. Obviously, for those skilled in the art, the above disclosure is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application, and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0058] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0059] Similarly, it should be noted that, in order to simplify the description of the present application and thus aid in the understanding of one or more embodiments, the foregoing description of the embodiments of the present application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of the present application requires more features than those mentioned in the claims. In fact, the embodiments contain fewer features than all the features of the single embodiments disclosed above.

[0060] In some embodiments, numbers describing the quantity of components and attributes are used. It should be understood that such numbers used in the description of embodiments are modified in some examples with the terms "approximately," "approximately," or "generally." Unless otherwise stated, "approximately," "approximately," or "generally" indicates that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are approximate values, which may be changed depending on the characteristics required by individual embodiments. In some embodiments, numerical parameters should take into account specified significant digits and employ a general method of digit reservation. Although the numerical ranges and parameters used to confirm their breadth of scope in some embodiments of this application are approximate values, in specific embodiments, such values ​​are set as precisely as feasible.

[0061] Although this application has been described with reference to specific embodiments, those skilled in the art should recognize that the above embodiments are only used to illustrate this application, and various equivalent changes or substitutions can be made without departing from the spirit of this application. Therefore, any changes or modifications to the above embodiments within the essential spirit of this application will fall within the scope of the claims of this application.

Claims

1. A method for estimating and tracking interference signals in a Wi-Fi network, characterized in that, include: S1: Receive the analog wireless signal to be evaluated; S2: Perform analog-to-digital conversion on the analog wireless signal to be evaluated to obtain a digital signal; S3: Convert the digital signal into a frequency domain signal; S4: Calculate the interference observation value at the current moment based on the power of each subcarrier in the frequency domain signal; Specifically, S1 to S4 are executed within the frame interval.

2. The method for estimating and tracking interference signals in a Wi-Fi network as described in claim 1, characterized in that, After a preset time elapsed from the start point of the frame interval, the simulated wireless signal to be evaluated is received.

3. The method for estimating and tracking interference signals in a Wi-Fi network as described in claim 2, characterized in that, The preset duration is less than the length of the frame interval and greater than the fall time of the previous frame of the frame interval.

4. The method for estimating and tracking interference signals in a Wi-Fi network as described in claim 1, characterized in that, S2 includes: S21: Perform analog-to-digital conversion on the analog wireless signal to be evaluated to obtain an initial digital signal; S22: The initial digital signal is downsampled to reduce the sampling rate, thereby obtaining the digital signal, wherein the sampling rate of the digital signal is at least twice the operating bandwidth of the analog wireless signal to be evaluated.

5. The method for estimating and tracking interference signals in a Wi-Fi network as described in claim 4, characterized in that, S3 includes: When the number of stored digital signal points reaches a preset number, a fast Fourier transform is performed on the stored digital signal to obtain the frequency domain signal.

6. The method for estimating and tracking interference signals in a Wi-Fi network as described in claim 5, characterized in that, The preset number of points is twice the number of points in the Fast Fourier Transform.

7. The method for estimating and tracking interference signals in a Wi-Fi network as described in claim 1, characterized in that, Also includes: S5: Based on the current interference observation value and the stored interference estimation result from the previous moment, the interference is recursively estimated through filtering to obtain the interference estimation result at the current moment.

8. The method for estimating and tracking interference signals in a Wi-Fi network as described in claim 7, characterized in that, The interference estimate from the previous moment is updated to the interference estimate from the current moment.

9. The method for estimating and tracking interference signals in a Wi-Fi network as described in claim 1, characterized in that, The frame interval includes the short frame interval (SIFS).

10. A communication device, characterized in that, include: Several modems; Several processors that are communicatively connected to the aforementioned several modems; as well as A plurality of memories communicatively connected to the plurality of processors and storing executable code, wherein when the plurality of processors cooperate with the plurality of modems to execute the executable code, the executable code is configured to: perform the method for estimating and tracking interference signals in a Wi-Fi network as described in any one of claims 1-9.

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