An adaptive frequency hopping system interference suppression method based on pilot signals

Abstract

This invention discloses an adaptive frequency hopping system interference suppression method based on pilot signals, comprising the following steps: Step 1, performing automatic gain control processing on the received signal; Step 2, performing sliding matching between the signal processed by automatic gain control in Step 1 and the local pseudocode sequence; Step 3, obtaining and recording the position of the maximum correlation peak and the corresponding correlation result by comparing the magnitude of the correlation peak amplitude after sliding matching within each pulse in Step 2; Step 4, extracting the effective data within the pulse from the position of the maximum correlation peak; Step 5, performing conjugate processing on the correlation result recorded within each pulse to obtain the anti-interference gain value of the current pulse, and multiplying it with the effective data within the pulse obtained in Step 4 to obtain the effective data after anti-interference gain processing. This invention can effectively suppress intra-pulse interference and prevent it from affecting the correct demodulation of the entire frame data.

Description

Technical Field

[0001] This invention belongs to the field of anti-interference technology and relates to an adaptive frequency hopping system interference suppression method based on pilot signals, which is applicable to frequency hopping systems. Background Technology

[0002] Modern military communications face two growing and prominent demands: first, reliability under strong interference, requiring improved system resistance to multi-domain strong interference in complex electromagnetic interference environments; and second, security under high-speed data transmission, ensuring signals are not intercepted by the enemy when transmitting real-time images, target data, and battlefield maps via data links. Based on these demands, high-speed frequency hopping has become the development direction of wireless communication technology.

[0003] To further improve the system's anti-interference capability, especially its ability to resist partial frequency band suppression interference, relying solely on the interference tolerance of the frequency hopping system is insufficient to achieve a significant performance improvement. Corresponding processing in the signal domain is still necessary to complete interference cancellation. Traditional signal domain processing methods require interference identification and cancellation, but suffer from cumbersome interference identification threshold settings and a lack of adaptive adjustment. This often necessitates resetting the interference detection threshold for different frequency hopping systems, increasing implementation complexity. Summary of the Invention

[0004] (I) Purpose of the Invention

[0005] The purpose of this invention is to address the high complexity of traditional signal domain anti-interference methods for frequency hopping systems under partial band suppression interference, and to propose an adaptive frequency hopping system interference suppression method based on pilot signals.

[0006] (II) Technical Solution

[0007] To address the aforementioned technical problems, this invention provides an adaptive frequency hopping system interference suppression method based on pilot signals, specifically comprising the following steps:

[0008] Step 1: Perform automatic gain control processing 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 according to every L agc Each symbol is used to divide a data block into N. agc Each data block contains L. agc The average of the symbols is calculated to obtain the average energy of each data block:

[0010]

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

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

[0013] Step 1.3 Based on the obtained automatic gain value, perform automatic gain control on each data block to obtain the pulse signal after automatic gain control.

[0014]

[0015] Step 2: Perform sliding matching between the signal processed by automatic gain control in Step 1 and the local pseudocode sequence, which can be expressed by formula (3):

[0016]

[0017] Among them, R k (τ) represents the result after sliding matching for the k-th pulse, C(n) c ) represents the local pseudocode sequence, N c The length of the local pseudocode sequence.

[0018] Step 3: By comparing the magnitude of the correlation peak after sliding matching within each pulse in Step 2, obtain and record the position of the maximum correlation peak and the corresponding correlation result. Let the position of the maximum correlation peak be... The corresponding results are:

[0019] Step 4: Extract the effective data D within the pulse from the position of the maximum correlation peak. k It can be expressed by formula (4):

[0020]

[0021] Step 5: Record the relevant results within each pulse. Perform conjugate processing to obtain the anti-interference gain value of the current pulse, and compare it with the effective intra-pulse data D obtained in step four. k Multiplying these results yields the effective data after anti-interference gain processing, which can be expressed by formula (5):

[0022]

[0023] in, R represents k The conjugate of (·) is taken.

[0024] (III) Beneficial Effects

[0025] The pilot-based adaptive frequency hopping system interference suppression method provided by the above technical solution avoids detecting interference in the signal domain compared with traditional signal domain anti-interference methods, thereby eliminating the disadvantage of cumbersome interference detection threshold settings. This invention uses automatic gain control to suppress the signal amplitude within the interference pulse, and uses the peak detection result obtained by the sliding correlation of dispersed pilots within the pulse to obtain the signal energy within the pulse. Through the positive correlation between the signal energy within the pulse and the anti-interference gain value, it effectively suppresses interference within the pulse and avoids it affecting the correct demodulation of the entire frame data. Attached Figure Description

[0026] Figure 1 This is a signal structure diagram of the present invention, "An Adaptive Frequency Hopping System Interference Suppression Method Based on Pilots";

[0027] Figure 2 This is a flowchart of the processing of the present invention, "An Adaptive Frequency Hopping System Interference Suppression Method Based on Pilots";

[0028] Figure 3 , Figure 4 , Figure 5 The figures are time-domain diagrams of the received signal with interference, time-domain diagram after automatic gain control, and time-domain diagram after anti-interference processing within a single pulse, respectively, when 20% band interference with an interference ratio of 30dB is added to the present invention "An Adaptive Frequency Hopping System Interference Suppression Method Based on Pilot". Detailed Implementation

[0029] To make the objectives, contents, and advantages of the present invention clearer, the specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples.

[0030] To overcome the complexity of traditional interference detection and elimination methods when frequency hopping systems face partial-band suppression interference, this invention proposes an adaptive frequency hopping system interference suppression method based on pilot signals. By using pilot signals within the frequency hopping pulse for correlation detection, the anti-interference gain value within the pulse is adaptively obtained. The anti-interference gain value is then used to adjust the signal gain within the pulse, suppressing the energy of the interfering pulse and achieving effective resistance to partial-band suppression interference.

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

[0032] Step 1: Perform automatic gain control processing 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 according to every Lagc Each symbol is used to divide a data block into N. agc Each data block contains L. agc The average of the symbols is calculated to obtain the average energy of each data block:

[0034]

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

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

[0037] Step 1.3 Based on the obtained automatic gain value, perform automatic gain control on each data block to obtain the pulse signal after automatic gain control.

[0038]

[0039] Step 2: Perform sliding matching between the signal processed by automatic gain control in Step 1 and the local pseudocode sequence, which can be expressed by formula (3):

[0040]

[0041] Among them, R k (τ) represents the result after sliding matching for the k-th pulse, C(n) c ) represents the local pseudocode sequence, N c The length of the local pseudocode sequence.

[0042] Step 3: By comparing the magnitude of the correlation peak after sliding matching within each pulse in Step 2, obtain and record the position of the maximum correlation peak and the corresponding correlation result. Let the position of the maximum correlation peak be... The corresponding results are:

[0043] Step 4: Extract the effective data D within the pulse from the position of the maximum correlation peak. k It can be expressed by formula (4):

[0044]

[0045] Step 5: Record the relevant results within each pulse. Perform conjugate processing to obtain the anti-interference gain value of the current pulse, and compare it with the effective intra-pulse data D obtained in step four. k Multiplying these results yields the effective data after anti-interference gain processing, which can be expressed by formula (5):

[0046]

[0047] in, R represents k The conjugate of (·) is taken.

[0048] Thus, steps one through five complete the interference suppression of the frequency hopping system based on pilot adaptation.

[0049] go through Figure 3 , Figure 4 , Figure 5 As can be seen from the comparison, the interference present in the received signal is successfully suppressed after processing by the interference suppression method of the present invention.

[0050] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A pilot-based adaptive frequency hopping system interference suppression method, characterized in that, Includes the following steps: Step 1: Perform automatic gain control processing on the received signal; Step 2: Perform sliding matching between the signal processed by automatic gain control in Step 1 and the local pseudocode sequence; Step 3: By comparing the magnitude of the correlation peak after sliding matching within each pulse in Step 2, obtain the position of the maximum correlation peak and the corresponding correlation result, and record them; Step 4: Extract the valid data within the pulse from the position of the maximum correlation peak; Step 5: Perform conjugate processing on the relevant 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 pilot-based adaptive frequency hopping system interference suppression method as described in claim 1, characterized in that, Step one 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 according to every L agc Each symbol is used to divide a data block into N. agc Each data block contains L. agc The average of the symbols is calculated to obtain the average energy of each data block; Step 1.2 Calculate the reciprocal of the average energy of each data block to obtain the automatic gain value corresponding to each data block; Step 1.3 Based on the obtained automatic gain value, perform automatic gain control on each data block to obtain the pulse signal after automatic gain control.

3. The pilot-based adaptive frequency hopping system interference suppression method as described in claim 2, characterized in that, In step 1.1, Where k represents the received pulse number, K represents the number of received pulses, and k = 0, 1, ..., K-1.

4. The pilot-based adaptive frequency hopping system interference suppression method as described in claim 3, characterized in that, In step 1.3, 5. The pilot-based adaptive frequency hopping system interference suppression method as described in claim 4, characterized in that, In step two, sliding matching is represented by formula (3): Among them, R k (τ) represents the result after sliding matching for the k-th pulse, C(n) c ) represents the local pseudocode sequence, N c The length of the local pseudocode sequence.

6. The pilot-based adaptive frequency hopping system interference suppression method as described in claim 5, characterized in that, In step three, the position of the maximum correlation peak is set as... The corresponding results are 7. The pilot-based adaptive frequency hopping system interference suppression method as described in claim 6, characterized in that, In step four, the valid data D k This can be expressed by formula (4):

8. The pilot-based adaptive frequency hopping system interference suppression method as described in claim 7, characterized in that, In step five, the effective data after anti-interference gain processing is represented by formula (5): in, R represents k The conjugate treatment of (·).

9. The application of the pilot-based adaptive frequency hopping system interference suppression method as described in claim 8 in frequency hopping system interference suppression.

10. The application of the pilot-based adaptive frequency hopping system interference suppression method as described in claim 8 in the field of anti-interference technology.

Images