Frequency hopping system interference suppression method based on pilot frequency self-adaption

Abstract

The invention discloses a frequency hopping system interference suppression method based on pilot frequency self-adaption. The method comprises the following steps: step 1, performing automatic gain control processing on a received signal; step 2, performing sliding matching on the signal subjected to automatic gain control processing in the step 1 and a local pseudo code sequence; step 3, obtaining and recording the maximum correlation peak position and the corresponding correlation result by comparing the amplitude of the correlation peak value after sliding matching in each pulse in the step 2; 4, intercepting effective data in the pulse from the position of the maximum correlation peak; and step 5, performing conjugation processing on the related result recorded in each pulse to obtain an anti-interference gain value of the current pulse, and multiplying the anti-interference gain value with the effective data in the pulse obtained in the step 4 to obtain effective data after anti-interference gain processing. According to the invention, the interference in the pulse can be effectively suppressed and is prevented from influencing the correct demodulation of the whole frame data.

Description

Technical Field

[0001] The invention belongs to the technical field of anti-interference, and relates to a method for suppressing interference of a frequency hopping system based on pilot frequency adaptation, which is suitable for the frequency hopping system. Background Art

[0002] There are two growing and prominent demands in modern communications: one is reliability under strong interference, which requires improving the system's ability to resist multi-domain strong interference in complex electromagnetic interference environments; the other is security under high-speed data transmission, which ensures that the signal is not intercepted when real-time images, target data, maps and other information need to be transmitted using data links. Based on the above demands, high-speed frequency hopping has become the development direction of wireless communication technology.

[0003] In order to further improve the anti-interference capability of the system, especially the ability to resist partial band suppression interference, it is difficult to significantly improve the performance by relying solely on the anti-interference tolerance of the frequency hopping system. It is still necessary to perform corresponding processing in the signal domain to complete the interference elimination. The traditional signal domain processing method requires interference identification and interference elimination, but there are problems such as cumbersome setting of the interference identification threshold and the inability to adjust adaptively. This often leads to the need to reset the interference detection threshold for different frequency hopping systems, which increases the complexity of implementation. Summary of the invention

[0004] (I) Purpose of the invention

[0005] The purpose of the present invention is to propose a method for suppressing interference in a frequency hopping system based on pilot adaptation, in view of the defect of high complexity of traditional signal domain anti-interference methods when the frequency hopping system is affected by partial frequency band suppression interference.

[0006] (II) Technical solution

[0007] In order to solve the above technical problems, the present invention provides a method for suppressing interference in a frequency hopping system based on pilot adaptation, which specifically comprises the following steps:

[0008] Step 1: Automatic gain control processing is performed on the received signal, as follows:

[0009] Step 1.1 The received signal is divided into pulses to obtain the pulse signal r k (n), the pulse signal is based on each L agc Symbols are divided into N blocks agc data blocks, for each data block L agc The average of the symbols is calculated to obtain the average energy of each data block:

[0010]

[0011] Wherein, k represents the received pulse sequence number, k=0, 1,…, K-1.

[0012] Step 1.2 calculates the inverse of the energy average value of each data block to obtain the automatic gain value corresponding to each data block;

[0013] Step 1.3: Perform automatic gain control on each data block based on the obtained automatic gain value to obtain a pulse signal after automatic gain control.

[0014]

[0015] Step 2: Sliding matching is performed between the signal processed by the automatic gain control in step 1 and the local pseudo code sequence, which can be expressed by formula (3):

[0016]

[0017] Among them, R k (τ) is the result of the kth pulse sliding matching, C(nc) is the local pseudo code sequence, N c is the length of the local pseudo code sequence.

[0018] Step 3: By comparing the correlation peak amplitude after sliding matching in each pulse in step 2, the maximum correlation peak position and the corresponding correlation result are obtained and recorded. The maximum correlation peak position is set to The corresponding results are

[0019] Step 4: Extract the effective data D in the pulse from the maximum correlation peak position k , which can be expressed by formula (4):

[0020]

[0021] Step 5: Correlation results recorded in each pulse Perform conjugate processing to obtain the anti-interference gain value of the current pulse, and compare it with the effective data D in the pulse obtained in step 4 k Multiply them together to get the effective data after anti-interference gain processing, which can be expressed by formula (5):

[0022]

[0023] in, Represents R k (·) is conjugated.

[0024] (III) Beneficial effects

[0025] The interference suppression method for a frequency hopping system based on pilot adaptation provided by the above technical solution can avoid detecting interference in the signal domain, thereby eliminating the adverse effects of the cumbersome setting of the interference detection threshold, compared with the traditional signal domain anti-interference method. The present invention uses automatic gain control to lower the signal amplitude in the interference pulse, and uses the peak detection result obtained by the sliding correlation of the scattered pilot in the pulse to obtain the signal energy in the pulse. Through the positive correlation between the signal energy in the pulse and the anti-interference gain value, the interference in the pulse is effectively suppressed to prevent it from affecting the correct demodulation of the entire frame of data. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a signal structure diagram of "a method for suppressing interference in a frequency hopping system based on pilot adaptation" of the present invention;

[0027] Figure 2 It is a processing flow chart of "a method for suppressing interference in a frequency hopping system based on pilot adaptation" of the present invention;

[0028] Figure 3 , Figure 4 , Figure 5 They are respectively the interference time domain diagram of the received signal, the time domain diagram after automatic gain control and the time domain diagram after anti-interference processing in a single pulse when 20% band interference with a signal-to-interference ratio of 30dB is added to the "interference suppression method of a frequency hopping system based on pilot adaptation" of the present invention. DETAILED DESCRIPTION

[0029] In order to make the purpose, content and advantages of the present invention more clear, the specific implementation methods of the present invention are further described in detail below in conjunction with the drawings and examples.

[0030] In order to overcome the problem of complex implementation of traditional interference detection and elimination methods when a frequency hopping system faces partial frequency band suppression interference, the present invention proposes a frequency hopping system interference suppression method based on pilot adaptation, which uses the pilot in the frequency hopping pulse for correlation detection, adaptively obtains the anti-interference gain value in the pulse, and uses the anti-interference gain value to adjust the signal gain in the pulse, suppresses the energy of the interference pulse, and achieves effective resistance to partial frequency band suppression interference.

[0031] Reference Figure 1 and Figure 2 As shown, the interference suppression method of the frequency hopping system based on pilot adaptation in this embodiment specifically includes the following steps:

[0032] Step 1: Automatic gain control processing is performed on the received signal, as follows:

[0033] Step 1.1 The received signal is divided into pulses to obtain the pulse signal r k (n), the pulse signal is based on each L agcSymbols are divided into N blocks agc data blocks, for each data block L agc The average of the symbols is calculated to obtain the average energy of each data block:

[0034]

[0035] Wherein, k represents the received pulse sequence number, k=0, 1,…, K-1.

[0036] Step 1.2 calculates the inverse of the energy average value of each data block to obtain the automatic gain value corresponding to each data block;

[0037] Step 1.3: Perform automatic gain control on each data block based on the obtained automatic gain value to obtain a pulse signal after automatic gain control.

[0038]

[0039] Step 2: Sliding matching is performed between the signal processed by the automatic gain control in step 1 and the local pseudo code sequence, which can be expressed by formula (3):

[0040]

[0041] Among them, R k (τ) is the result of the kth pulse sliding matching, C(nc) is the local pseudo code sequence, N c is the length of the local pseudo code sequence.

[0042] Step 3: By comparing the correlation peak amplitude after sliding matching in each pulse in step 2, the maximum correlation peak position and the corresponding correlation result are obtained and recorded. The maximum correlation peak position is set to The corresponding results are

[0043] Step 4: Extract the effective data D in the pulse from the maximum correlation peak position k , which can be expressed by formula (4):

[0044]

[0045] Step 5: Correlation results recorded in each pulse Perform conjugate processing to obtain the anti-interference gain value of the current pulse, and compare it with the effective data D in the pulse obtained in step 4 k Multiply them together to get the effective data after anti-interference gain processing, which can be expressed by formula (5):

[0046]

[0047] in, Represents R k (·) is conjugated.

[0048] So far, the interference suppression of the frequency hopping system based on pilot adaptation has been completed from step one to step five.

[0049] go through Figure 3 , Figure 4 , Figure 5 By comparison, it can be seen that after being processed by the interference suppression method of the present invention, the interference existing in the received signal is successfully suppressed.

[0050] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for suppressing interference in a frequency hopping system based on pilot adaptation, characterized in that: The following steps are involved: Step 1, performing automatic gain control processing on the received signal; Step 2: Sliding matching is performed between the signal processed by the automatic gain control in step 1 and the local pseudo code sequence; Step 3: By comparing the correlation peak amplitude after sliding matching in each pulse in step 2, the maximum correlation peak position and the corresponding correlation result are obtained and recorded; Step 4: extract valid data in the pulse from the position of the maximum correlation peak; Step 5: Perform conjugate processing on the correlation results recorded in each pulse to obtain the anti-interference gain value of the current pulse, and multiply it with the effective data in the pulse obtained in step 4 to obtain the effective data after anti-interference gain processing.

2. The method for suppressing interference in a frequency hopping system based on pilot adaptation as claimed in claim 1, characterized in that: Step 1 includes the following sub-steps: Step 1.1 The received signal is divided into pulses to obtain the pulse signal r k (n), the pulse signal is based on each L agc Symbols are divided into N blocks agc data blocks, for each data block L agc The symbols are averaged to obtain the average energy value of each data block; Step 1.2 calculates the inverse of the energy average value of each data block to obtain the automatic gain value corresponding to each data block; Step 1.3: Perform automatic gain control on each data block based on the obtained automatic gain value to obtain a pulse signal after automatic gain control.

3. The method for suppressing interference in a frequency hopping system based on pilot adaptation as claimed in claim 2, characterized in that: In step 1.1, Wherein, k represents the received pulse sequence number, K represents the number of received pulses, k=0,1,…,K-1.

4. The method for suppressing interference in a frequency hopping system based on pilot adaptation as claimed in claim 3, characterized in that: In step 1.3, 5. The method for suppressing interference in a frequency hopping system based on pilot adaptation as claimed in claim 4, characterized in that: In step 2, sliding matching is expressed by formula (3): Among them, R k (τ) is the result of the kth pulse sliding matching, C(nc) is the local pseudo code sequence, N c is the length of the local pseudo code sequence.

6. The method for suppressing interference in a frequency hopping system based on pilot adaptation as claimed in claim 5, characterized in that: In step 3, the maximum correlation peak position is set to The corresponding results are 7. The method for suppressing interference in a frequency hopping system based on pilot adaptation as claimed in claim 6, characterized in that: In step 4, the valid data D k It is expressed by formula (4):

8. The method for suppressing interference in a frequency hopping system based on pilot adaptation as claimed in claim 7, characterized in that: In step 5, the effective data after anti-interference gain processing is expressed by formula (5): in, Represents R k (·) is conjugated.

9. Application of the method for interference suppression of a frequency hopping system based on pilot adaptation as claimed in claim 8 in interference suppression of a frequency hopping system.

10. Application of the interference suppression method of a frequency hopping system based on pilot adaptation as claimed in claim 8 in the field of anti-interference technology.

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