Narrowband interference suppression method and system for direct sequence spread spectrum system

Abstract

The invention provides a narrow-band interference suppression method and system for a direct sequence spread spectrum system, and relates to the technical field of satellite communication anti-interference. The method comprises the following steps: determining the noise power of an obtained receiving signal, wherein the receiving signal is a frequency domain signal; determining an interference threshold according to the noise power of the received signal; determining an interference signal and an interference parameter thereof according to the interference threshold; and according to the interference parameter, performing interference filtering on the received signal through a high-pass filter to obtain a signal after interference suppression. According to the method, interference parameters can be accurately estimated in a frequency domain, the most matched high-pass filter is determined according to the determined interference parameters, interference is filtered through the high-pass filter to obtain the signal after interference suppression, the suppression capability of the direct sequence spread spectrum system on strong narrow-band interference can be remarkably improved, the complexity of the mode is greatly reduced, and the method is suitable for large-scale popularization and application. And the practicability is higher.

Description

Technical Field

[0001] The present invention relates to the field of satellite communication anti-interference technology, and more specifically, to a method and system for suppressing narrowband interference in a direct sequence spread spectrum system. Background Art

[0002] In wireless communication systems, narrowband interference is a common problem that affects the quality of signal transmission. Direct sequence spread spectrum (DSSS for short) technology multiplies the original information signal with a pseudo-random sequence to broaden the signal spectrum to a frequency band wider than the original signal bandwidth, thereby effectively improving the signal's anti-interference ability. DSSS technology uses the expanded spectrum to reduce the impact of interference, allowing signals to be transmitted more stably and reliably in complex wireless environments. DSSS systems have significant advantages in resisting narrowband interference. At the receiving end, despreading technology can restore the expanded signal to the original signal, while evenly dispersing the power of the interference signal throughout the spectrum, significantly reducing its impact on communication. This makes DSSS widely used in wireless communication scenarios to combat various forms of narrowband interference.

[0003] However, in practical applications, DSSS systems still face the challenge of strong narrowband interference. When the power of narrowband interference is much higher than the signal power, even spread spectrum systems may be seriously affected, resulting in system performance degradation or even collapse. In this case, relying solely on the spectrum broadening characteristics of DSSS is not enough to ensure the reliability of communication.

[0004] At present, the commonly used elimination methods in direct sequence spread spectrum systems are time domain adaptive filtering algorithms such as the least mean square error (LMS), recursive least squares algorithm (RLS), and the continuous mean excision (CME) algorithm in the transform domain. Among them, the main disadvantages of the LMS algorithm are slow convergence speed and poor adaptability to interference. Although the algorithm performance of RLS is better than that of LMS, its implementation complexity is higher and it also has higher requirements for numerical stability; however, the CME algorithm can suppress interference because it operates in the transform domain, but its implementation complexity is higher. Summary of the invention

[0005] The purpose of this specification is to provide a method for suppressing narrowband interference in a direct sequence spread spectrum system, which can solve the above-mentioned problems existing in traditional narrowband interference suppression methods.

[0006] The embodiments of this specification are implemented as follows:

[0007] On the one hand, this specification provides a method for suppressing narrowband interference in a direct sequence spread spectrum system, which mainly includes:

[0008] Determining the noise power of the acquired received signal, wherein the received signal is a frequency domain signal;

[0009] Determining an interference threshold according to the noise power of the received signal;

[0010] Determining an interference signal and its interference parameters according to the interference threshold;

[0011] According to the interference parameter, the received signal is filtered out through a high-pass filter to obtain an interference-suppressed signal.

[0012] On the other hand, the present specification provides a direct sequence spread spectrum system narrowband interference suppression system, mainly comprising:

[0013] An acquisition module, used to determine the noise power of an acquired received signal, wherein the received signal is a frequency domain signal;

[0014] A threshold determination module, which determines an interference threshold according to the noise power of the received signal;

[0015] An interference determination module, used to determine an interference signal and its interference parameters according to the interference threshold;

[0016] The filtering module is used to filter the received signal through a high-pass filter according to the interference parameter to obtain an interference-suppressed signal.

[0017] The embodiments of this specification have at least the following advantages or beneficial effects:

[0018] This narrowband interference suppression method can accurately estimate interference parameters in the frequency domain, determine the most matching high-pass filter according to the determined interference parameters, and obtain the interference-suppressed signal by filtering out interference through the high-pass filter. It can significantly improve the direct sequence spread spectrum system's ability to suppress strong narrowband interference, and the complexity of the above method is greatly reduced, making it more practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of this specification, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present specification and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 A flowchart of a method for suppressing narrowband interference in a direct sequence spread spectrum system provided in this specification;

[0021] Figure 2Another schematic diagram of a flow chart of a method for suppressing narrowband interference in a direct sequence spread spectrum system provided in this specification;

[0022] Figure 3 A schematic diagram of simulation results of a method for suppressing narrowband interference in a direct sequence spread spectrum system provided in this specification;

[0023] Figure 4 This is a schematic diagram of a narrowband interference suppression system for a direct sequence spread spectrum system provided in this specification. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of this specification more clear, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are part of the embodiments of this specification, not all of the embodiments. Generally, the components of the embodiments of this specification described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Please refer to Figure 1 and Figure 2 An embodiment of the present specification provides a method for suppressing narrowband interference in a direct sequence spread spectrum system, which mainly includes:

[0026] Step 102: determining the noise power of the acquired received signal, where the received signal is a frequency domain signal;

[0027] Step 104: determining an interference threshold according to the noise power of the received signal;

[0028] Step 106: Determine the interference signal and its interference parameters according to the interference threshold;

[0029] Step 108: According to the interference parameter, the received signal is filtered out through a high-pass filter to obtain an interference-suppressed signal.

[0030] In this embodiment, before step 102, the received signal is low-pass filtered to remove out-of-band interference.

[0031] In this embodiment, after low-pass filtering, the above-mentioned received signal (which is a time domain signal) is multiplied by the Hanning window, windowing processing is performed, and then the received signal after the windowing processing is Fourier transformed to obtain a frequency domain signal. The above-mentioned windowing processing method can effectively reduce spectrum leakage, and the accuracy of interference detection and suppression can be further improved.

[0032] Specifically, the above method can accurately estimate the interference parameters in the frequency domain, determine the most matching high-pass filter according to the determined interference parameters, and obtain the interference suppressed signal by filtering out the interference through the high-pass filter. This can significantly improve the direct sequence spread spectrum system's ability to suppress strong narrowband interference, and the complexity of the above method is greatly reduced, making it more practical.

[0033] In this embodiment, the specific implementation of step 102 is:

[0034] Step 112: grouping the received signals according to the number of points to obtain a plurality of signal groups;

[0035] Step 114, calculating the average power of each signal group in the frequency domain;

[0036] Step 116, determining two signal groups with the largest average power;

[0037] Step 118: Determine the noise power of the received signal according to the average power of other signal groups after excluding the two signal groups with the largest average power.

[0038] In this embodiment, each of the above signal groups is a received signal that has been subjected to windowing processing and Fourier transformation.

[0039] In this embodiment, by eliminating the two signal groups with the largest average power (ie, the two signal groups with the largest and second largest average power), the noise power can be accurately determined, thereby determining the above interference threshold.

[0040] In this embodiment, the average power P between the other signal groups is calculated based on the average power of the other signal groups after removing the two signal groups with the largest average power. mean , which is the noise power, then the above interference threshold Th is:

[0041] Th=σP mean

[0042] Among them, σ is the simulation value and can be taken as 10.

[0043] In this embodiment, the interference threshold determined in the above manner can accurately find the position of the interference signal in the received signal.

[0044] In this embodiment, the specific implementation of step 106 is:

[0045] Step 122, determining whether the two signal groups with the largest average power are adjacent groups;

[0046] Step 124: If yes, determine the interference signal in the two signal groups with the largest average power;

[0047] Step 126: If not, determine the interference signal in the signal group with the largest average power.

[0048] In this embodiment, the specific implementation of step 122 is:

[0049] Step 132: The two signal groups with the largest average power are P x and P y ;

[0050] Step 134: Determine whether the condition xy∈{±1,±m} is satisfied, where m is the difference between the maximum sequence number of the group and the minimum sequence number of the group.

[0051] In this embodiment, x and y are serial numbers of the signal groups, and whether the two signal groups with the largest average power are adjacent groups is determined by processing the serial numbers.

[0052] In this embodiment, the specific implementation of step 106 is:

[0053] Step 142: Use the two signal groups with the largest average power or the signal group with the largest average power as the signal group to be tested;

[0054] Step 144, determining the first signals greater than the interference threshold at both ends of the signal group to be tested, and obtaining the position of the first signal point and the position of the second signal point;

[0055] Step 146: Determine the position of the interference center according to the position of the first signal point and the position of the second signal point;

[0056] Step 148: Determine the interference center frequency according to the sampling rate of the received signal, the number of signal points and the position of the interference center;

[0057] Step 150: Determine the bandwidth of the interference signal according to the sampling rate of the received signal, the number of signal points, and the position of the first signal point and the position of the second signal point. In this embodiment, the position of the interference signal and its corresponding center frequency and bandwidth can be accurately determined in the above manner.

[0058] In this embodiment, the specific implementation of step 144 is as follows:

[0059] Step 152: The signal group to be tested is D=d1d2, ...d i , ..., d N , where d i is the i-th signal point of the signal group to be tested, and N is the number of signal points of the signal group to be tested;

[0060] Step 154: Find the first signal point greater than the interference threshold from one end of the signal group D to be tested, and determine the position of the first signal point;

[0061] Step 156: Find the first signal point greater than the interference threshold from the other end of the signal group D to be measured, and determine the position of the second signal point.

[0062] Specifically, move from the leftmost side of D to the right and find the first signal point that is greater than the above interference threshold, and record the index as z1. If all values ​​in D are less than the threshold Th, it is considered that there is no interference, and the anti-interference process ends, and the signal is passed directly. Move from the rightmost side of D to the left and find the first point that is greater than the threshold, and record the index as z2. According to z1, z2, P x , P y Determine the position of the narrowband interference in the above received signal, recorded as z3, and the calculation method is as follows:

[0063]

[0064]

[0065] Wherein, N0 is the length of the data of the signal group, N fft is the number of Fourier transform points.

[0066] In this embodiment, the interference center position can be accurately determined through the above method, and the narrowband interference center frequency and bandwidth can be determined.

[0067] In this embodiment, the specific implementation of step 108 is:

[0068] Step 162: Determine a high-pass filter coefficient adapted to the received signal according to the bandwidth of the interference signal.

[0069] Step 164: Generate a first sine-cosine signal and a second sine-cosine signal according to the interference center frequency;

[0070] Step 166: Convert the received signal to baseband using the first sine and cosine signals;

[0071] Step 168: filtering out interference of the received signal converted to the baseband according to a high-pass filter coefficient adapted to the received signal, to obtain a signal without interference;

[0072] Step 170: Obtain the interference-suppressed signal according to the second sine and cosine signals and the signal from which interference is filtered out.

[0073] In this embodiment, the frequency of the first sine-cosine signal is opposite to the interference center frequency; the frequency of the second sine-cosine signal is the same as the interference center frequency.

[0074] In this embodiment, a direct digital frequency synthesizer (DDS) can be used to generate a sine and cosine signal with the same center frequency as the above-mentioned interference. The first sine and cosine signal can be multiplied with the above-mentioned received signal to convert the narrowband interference of the received signal to the baseband. The narrowband interference of the baseband is filtered out by a high-pass filter with a high-pass filter coefficient adapted to the received signal. Then, a sine and cosine signal with the opposite center frequency of the above-mentioned interference generated by the DDS is used to multiply the second sine and cosine signal with the signal from which the interference is filtered out, thereby eliminating the influence of the first sine and cosine signal on the received signal.

[0075] In this embodiment, the above method is described in detail through the following examples:

[0076] The received signal is obtained and low-pass filtered to remove out-of-band interference; 4096 points of the time domain signal (i.e. the received signal) are intercepted and multiplied with the Hanning window to complete the windowing operation, and then a Fourier operation is performed.

[0077] The 4096 frequency domain data points are divided into 16 consecutive signal groups, each containing 256 signal points. The average power in each group is calculated and recorded as P1P2…P 15 P 16 , remove the two largest values, denoted as P x and P y , calculate the average power between the remaining 14 groups, denoted as P mean , take the threshold as Th = σP mean , after simulation, σ is taken as 10.

[0078] If P x and P y The corresponding index has the following relationship xy∈{±1,±15}, which indicates that interference may exist in adjacent groups and needs to be within the maximum value P x and the submaximum P y The corresponding adjacent groups are searched for narrowband interference. Where ±15 means that the indexes of x and y are 1 and 16.

[0079] like Then at the maximum value P x Look for narrowband interference within the corresponding group.

[0080] The two signal groups with the largest average power or the signal group with the largest average power are used as the signal group to be tested. The above signal group to be tested is D=d1d2 ， ..., d N , if xy∈{±1,±15}, then N=512, otherwise N=256.

[0081] Move from the leftmost side of D to the right, and find the first point that is greater than the threshold. Record the index as z1. If all values ​​in D are less than the threshold Th, there is no interference. If z1 is found, record z1.

[0082] Move from the rightmost side of D to the left, find the first point whose value is greater than the threshold, and record its index as z2.

[0083] According to z1, z2, P x , P y It is easy to get the position of narrowband interference corresponding to the 4096-point FFT, recorded as z3, which is:

[0084]

[0085]

[0086] Then the narrowband interference center frequency is:

[0087] f c =f s / 4096×z3

[0088] The narrowband interference bandwidth is:

[0089] B i =f s / 4096×(z2-z1)

[0090] where f s Indicates the sampling rate.

[0091] The first sine and cosine signals are generated by DDS and converted to baseband by multiplying the received signal.

[0092] Through narrow-band interference bandwidth B i Select appropriate high-pass filter coefficients to filter out baseband narrowband interference.

[0093] A second sine and cosine signal is then generated by DDS and multiplied with the received signal to eliminate the influence of the first sine and cosine signal on the received signal.

[0094] In this embodiment, the simulation results of the above method are specifically referred to Figure 3 ,It can be seen that the interference can be effectively suppressed by the above interference suppression method.

[0095] Please refer to Figure 4 Another embodiment of the present specification provides a direct sequence spread spectrum system narrowband interference suppression system, mainly comprising:

[0096] An acquisition module 202 is used to determine the noise power of the acquired received signal, where the received signal is a frequency domain signal;

[0097] A threshold determination module 204 determines an interference threshold according to the noise power of the received signal;

[0098] An interference determination module 206, configured to determine an interference signal and its interference parameters according to the interference threshold;

[0099] The filtering module 208 is used to filter the received signal for interference according to the interference parameter through a high-pass filter to obtain an interference-suppressed signal.

[0100] The narrowband interference suppression system can accurately estimate interference parameters in the frequency domain, determine the most matching high-pass filter according to the determined interference parameters, and obtain the interference-suppressed signal by filtering out interference through the high-pass filter. It can significantly improve the direct sequence spread spectrum system's ability to suppress strong narrowband interference, and the complexity of the above method is greatly reduced, making it more practical.

[0101] In this embodiment, the acquisition module 202 is used to group the received signal by the number of points to obtain multiple signal groups; calculate the average power of each signal group in the frequency domain; determine the two signal groups with the largest average power; and determine the noise power of the received signal according to the average power of other signal groups after eliminating the two signal groups with the largest average power. By eliminating the two signal groups with the largest average power (i.e., the two signal groups with the largest and second largest average power), the noise power can be accurately determined, thereby determining the above-mentioned interference threshold.

[0102] The interference determination module 206 is used to determine whether the two signal groups with the largest average power are adjacent groups; if so, determine the interference signal in the two signal groups with the largest average power; if not, determine the interference signal in the signal group with the largest average power. x and P y ; Determine whether the condition xy∈{±1, ±m} is satisfied, where m is the difference between the maximum group number and the minimum group number. Take the two signal groups with the largest average power or the signal group with the largest average power as the signal group to be tested; from the two ends of the signal group to be tested, respectively determine the first signal greater than the interference threshold at both ends of the signal group to be tested, and obtain the position of the first signal point and the position of the second signal point; determine the position of the interference center according to the position of the first signal point and the position of the second signal point; determine the interference center frequency according to the sampling rate of the received signal, the number of signal points and the position of the interference center; determine the bandwidth of the interference signal according to the sampling rate of the received signal, the number of signal points and the position of the first signal point and the position of the second signal point. Take the signal group to be tested as D=d1d2,..d i , .., d N , where d iis the ith signal point of the signal group to be tested, and N is the number of signal points of the signal group to be tested; from one end of the signal group D to be tested, find the first signal point greater than the interference threshold, and determine the position of the first signal point; from the other end of the signal group D to be tested, find the first signal point greater than the interference threshold, and determine the position of the second signal point. The position of the interference signal and its corresponding center frequency and bandwidth can be accurately determined in the above manner.

[0103] In this embodiment, the filtering module 208 is used to determine the high-pass filter coefficient adapted to the received signal according to the bandwidth of the interference signal. According to the interference center frequency, a first sine-cosine signal and a second sine-cosine signal are generated; the received signal is converted to baseband through the first sine-cosine signal; according to the high-pass filter coefficient adapted to the received signal, the interference of the received signal converted to baseband is filtered out to obtain a signal filtered out of interference; according to the second sine-cosine signal and the signal filtered out of interference, the signal after interference suppression is obtained. A sine-cosine signal with a center frequency opposite to the above-mentioned interference can be generated by DDS, and the first sine-cosine signal is multiplied with the above-mentioned received signal to convert the narrowband interference of the received signal to baseband, and the narrowband interference of the baseband is filtered out through the high-pass filter with the high-pass filter coefficient adapted to the received signal, and then the second sine-cosine signal is multiplied with the signal filtered out of interference through the sine-cosine signal with the same center frequency of the above-mentioned interference generated by DDS, so as to eliminate the influence of the first sine-cosine signal on the received signal.

[0104] Based on the same invention, another embodiment of the present specification further provides a computer-readable storage medium, wherein the computer-readable storage medium stores one or more programs, and when the one or more programs are executed by an electronic device including multiple application programs, the electronic device executes Figure 1 The corresponding embodiment provides a method for suppressing narrowband interference in a direct sequence spread spectrum system.

[0105] In this specification, each embodiment is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0106] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. 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.

[0107] Those skilled in the art will appreciate that the embodiments of this specification may be provided as methods, systems, or computer program products. Therefore, this specification may be in the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, this specification may be in the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0108] This specification is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of this specification. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that has the function specified in a box.

[0109] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0110] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0111] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0112] The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0113] The above is only an embodiment of the present application and is not intended to limit this specification. For those skilled in the art, this specification may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this specification should be included in the scope of the claims of this specification.

Claims

1. A method for suppressing narrowband interference in a direct sequence spread spectrum system, characterized in that: include: Determining the noise power of the acquired received signal, wherein the received signal is a frequency domain signal; Determining an interference threshold according to the noise power of the received signal; Determining an interference signal and its interference parameters according to the interference threshold; According to the interference parameter, the received signal is filtered out through a high-pass filter to obtain an interference-suppressed signal.

2. The method for suppressing narrowband interference in a direct sequence spread spectrum system according to claim 1, characterized in that: The step of determining the noise power of the received signal includes: Grouping the received signals according to the number of points to obtain a plurality of signal groups; Calculate the average power of each signal group in the frequency domain; Determine the two signal groups with the largest average power; The noise power of the received signal is determined according to the average power of other signal groups after excluding the two signal groups with the largest average power.

3. The method for suppressing narrowband interference in a direct sequence spread spectrum system according to claim 2, characterized in that: The determining, according to the interference threshold, an interference signal and its interference parameter comprises: Determine whether the two signal groups with the largest average power are adjacent groups; If so, the interference signal is determined in the two signal groups with the largest average power; If not, the interfering signal is determined in the signal group with the largest average power.

4. The method for suppressing narrowband interference in a direct sequence spread spectrum system according to claim 3, characterized in that: The step of determining whether the two signal groups with the largest average power are adjacent groups comprises: The two signal groups with the largest average power are P x and P y ; Determine whether the condition xy∈{±1,±m} is satisfied, where m is the difference between the maximum sequence number of the group and the minimum sequence number of the group.

5. The method for suppressing narrowband interference in a direct sequence spread spectrum system according to claim 3 or 4, characterized in that: The determining, according to the interference threshold, an interference signal and its interference parameter comprises: The two signal groups with the largest average power or the signal group with the largest average power are used as the signal group to be tested; From both ends of the signal group to be tested, respectively determine the first signals at both ends of the signal group to be tested that are greater than the interference threshold, and obtain the position of the first signal point and the position of the second signal point; Determining a position of an interference center according to a position of the first signal point and a position of the second signal point; Determine the interference center frequency according to the sampling rate of the received signal, the number of signal points and the position of the interference center; The bandwidth of the interference signal is determined according to the sampling rate of the received signal, the number of signal points, and the position of the first signal point and the position of the second signal point.

6. The method for suppressing narrowband interference in a direct sequence spread spectrum system according to claim 5, characterized in that: The step of respectively determining, from both ends of the signal group to be tested, first signals greater than the interference threshold at both ends of the signal group to be tested, and obtaining the position of the first signal point and the position of the second signal point comprises: The signal group to be tested is D=d1d2, ...d i , ..., d N , where d i is the i-th signal point of the signal group to be tested, and N is the number of signal points of the signal group to be tested; Finding a first signal point greater than the interference threshold from one end of the signal group D to be tested, and determining the position of the first signal point; From the other end of the signal group D to be measured, find the first signal point that is greater than the interference threshold, and determine the position of the second signal point.

7. The method for suppressing narrowband interference in a direct sequence spread spectrum system according to claim 5, characterized in that: The filtering out interference from the received signal according to the interference parameter to obtain an interference suppressed signal includes: According to the bandwidth of the interference signal, a high-pass filter coefficient adapted to the received signal is determined.

8. The method for suppressing narrowband interference in a direct sequence spread spectrum system according to claim 7, characterized in that: After determining the high-pass filter coefficient adapted to the received signal according to the bandwidth of the interference signal, the method further includes: Generating a first sine-cosine signal and a second sine-cosine signal according to the interference center frequency; converting the received signal to baseband by using the first sine and cosine signals; filtering out interference of the received signal converted to baseband according to a high-pass filter coefficient adapted to the received signal, to obtain a signal without interference; The interference suppressed signal is obtained according to the second sine and cosine signals and the signal from which interference is filtered out.

9. The method for suppressing narrowband interference in a direct sequence spread spectrum system according to claim 8, characterized in that: The frequency of the first sine-cosine signal is opposite to the interference center frequency; the frequency of the second sine-cosine signal is the same as the interference center frequency.

10. A direct sequence spread spectrum system narrowband interference suppression system, characterized in that: include: An acquisition module, used to determine the noise power of an acquired received signal, wherein the received signal is a frequency domain signal; A threshold determination module, which determines an interference threshold according to the noise power of the received signal; An interference determination module, used to determine an interference signal and its interference parameters according to the interference threshold; The filtering module is used to filter the received signal through a high-pass filter according to the interference parameter to obtain an interference-suppressed signal.

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