A method and system for pulse interference identification in satellite navigation receiving equipment

Abstract

The present invention relates to the field of satellite navigation technology, and discloses a method for pulse interference identification in a satellite navigation receiving device, comprising the following steps: step S1. collecting data from a satellite navigation receiving device, and obtaining a data envelope according to the collected data; step S2. determining the maximum and minimum values ​​of the data envelope; step S3. calculating a low threshold and a high threshold according to the maximum and minimum values ​​of the data envelope; step S4. calculating the data proportion between the high and low thresholds of the data envelope; step S5. counting the interference type according to the data proportion between the high and low thresholds to determine whether it is pulse interference. The present invention also discloses a system for pulse interference identification in a satellite navigation receiving device. The present invention has the advantages of low computational complexity and high recognition accuracy, and provides an important basis for satellite navigation receiving devices to select appropriate interference suppression measures.

Description

Technical Field

[0001] The present invention relates to the field of satellite navigation technology, and in particular to a method and system for pulse interference identification in a satellite navigation receiving device, which has the advantages of low computational complexity and high identification accuracy, and provides an important basis for the satellite navigation receiving device to select appropriate interference suppression measures. Background Art

[0002] Satellite navigation systems can provide users with high-precision positioning, navigation and timing services, and have been widely used in all walks of life, creating huge economic value and social benefits. However, the vulnerability of satellite navigation systems is still an unavoidable problem, and satellite navigation receiving equipment is extremely susceptible to electromagnetic interference.

[0003] Electromagnetic interference can be divided into two categories based on time domain characteristics: pulse interference and continuous wave interference. Pulse interference is discontinuous and sometimes appears and sometimes disappears in the time domain, while continuous wave interference exists continuously in the time domain. Different anti-interference methods should be adopted to suppress the two types of interference. For example, for pulse interference, the pulse time domain zeroing method is generally used to suppress it, while for continuous wave interference, adaptive cancellation or frequency domain zeroing method is generally used to suppress it.

[0004] In order to improve the anti-interference ability of satellite navigation receiving equipment, after detecting electromagnetic interference, it is necessary to correctly identify the interference type and determine whether the interference is pulse interference or continuous wave interference, so as to take corresponding measures to suppress the interference. At present, there are many research results on the detection and suppression of electromagnetic interference, but in the identification of pulse interference, there are still problems such as low recognition accuracy, high implementation complexity or low intelligence. The existing technology uses a single threshold to estimate the pulse width and compares the pulse width with the threshold to identify pulse interference, but fails to make full use of the characteristic that the envelope samples of pulse interference are concentrated near the maximum and minimum values ​​of the envelope, and it is easy to misjudge Gaussian interference as pulse interference. Therefore, there is an urgent need for an invention that can complete pulse interference identification without the help of manual intervention and only relies on the device itself. The present invention has the advantages of low computational complexity and high recognition accuracy, and provides an important basis for satellite navigation receiving equipment to select appropriate interference suppression measures. Summary of the invention

[0005] The purpose of the present invention is to provide a method and system for pulse interference identification in a satellite navigation receiving device, which has the advantages of low computational complexity and high identification accuracy, and provides an important basis for the satellite navigation receiving device to select appropriate interference suppression measures.

[0006] The present invention is implemented by the following technical solution: A method for pulse interference identification in a satellite navigation receiving device comprises the following steps:

[0007] Step S1. Collecting data from a satellite navigation receiving device, and obtaining a data envelope based on the collected data;

[0008] Step S2. The digital signal processor in the receiving device determines the maximum and minimum values ​​of the data envelope;

[0009] Step S3. The digital signal processor in the receiving device calculates the lower threshold and the upper threshold according to the maximum value and the minimum value of the data envelope;

[0010] Step S4. The digital signal processor in the receiving device counts the data envelope data ratio between the high and low thresholds;

[0011] Step S5. The digital signal processor in the receiving device counts the interference type as pulse interference based on the data ratio between the high and low thresholds.

[0012] The present invention automatically identifies pulse interference according to the data envelope distribution characteristics, overcoming the shortcomings of the prior art such as low recognition accuracy, high implementation complexity or low intelligence, and can be used to provide an important basis for selecting appropriate interference suppression measures for satellite navigation receiving equipment, especially core equipment.

[0013] In order to better implement the present invention, further, step S1 includes:

[0014] The receiving antenna in the receiving device receives the electromagnetic wave signal transmitted by the navigation satellite and converts the electromagnetic wave signal into a radio frequency analog signal;

[0015] The RF analog signal is transmitted to the RF channel for filtering, frequency conversion and gain control, and converted into an analog intermediate frequency signal; the analog intermediate frequency signal is sampled and quantized, converted into a digital signal, and transmitted to a digital signal processor.

[0016] In order to better implement the present invention, further, step S1 also includes:

[0017] By collecting data, N data are obtained and set as x1, x2, x3, ..., xN;

[0018] According to the preset N data, the formula for obtaining the data packet is y k =[x k *conj(x k )] 1 / 2 ,k=1,2,...,N, where y k is the data envelope, function conj(·) is the conjugate function, and N is the data length, which is a positive integer.

[0019] According to the preset N data, the formula for obtaining the data packet has low computational complexity. Low computational complexity can be understood as that the subsequent steps only require maximum values, minimum values ​​and simple operations.

[0020] In order to better implement the present invention, further, step S2 includes:

[0021] Data Envelopment k The formula for the maximum value of y is max =max(y k ), k = 1, 2, ..., N;

[0022] Data Envelopment k The formula for the minimum value of y is min =min(y k ), k = 1, 2, ..., N;

[0023] Among them, the function max(·) represents the maximum value, and the function min(·) represents the minimum value.

[0024] In this technical solution, the data envelope y k The maximum and minimum values ​​range from 0 to 2 b-1 , b is the bit width (number of bits) of the data.

[0025] In order to better implement the present invention, further, step S3 includes:

[0026] The formula for the lower threshold is z L =y min +0.2(y max -y min );

[0027] The formula for the high threshold is z H =y max -0.2(y max -y min ).

[0028] In this technical solution, the high threshold and the low threshold are used to collect the statistical data envelope y k How many are greater than the lower threshold and less than the upper threshold.

[0029] In order to better implement the present invention, further, step S4 includes:

[0030] Statistical data envelope k Satisfy L <y k <z H The number of data is K;

[0031] The formula for the data ratio r between high and low thresholds is:

[0032] In this technical solution, compared with the traditional single threshold decision method, the method of the present invention adopts high and low dual threshold decisions, making full use of the characteristic that the envelope samples of pulse interference are concentrated near the maximum and minimum values ​​of the envelope, further improving the recognition accuracy.

[0033] In order to better implement the present invention, further, step S5 includes:

[0034] A data threshold between the high and low thresholds is preset to determine whether the data ratio r between the high and low thresholds is less than or equal to the threshold. If so, it is determined that the interference type received in the satellite navigation receiving device is pulse interference. If not, the interference type received in the satellite navigation receiving device is not pulse interference.

[0035] In this technical solution, it can be seen that the computational complexity of the entire pulse interference identification process is very low, and only a small amount of calculation and judgment is required.

[0036] In order to better implement the present invention, further, the present invention also provides a system for pulse interference identification in a satellite navigation receiving device, including a receiving device, a radio frequency channel, an AD converter and a digital signal processor, wherein:

[0037] A receiving device, wherein the receiving antenna in the receiving device is used to collect data, and is used to convert the electromagnetic wave signal transmitted by the navigation satellite received into a voltage or current signal for the radio frequency channel of the receiving device to acquire and process, and is used to obtain a data envelope according to the collected data;

[0038] The RF channel is located between the receiving antenna and the AD converter and is used to filter, convert and gain-control the received RF analog signal and convert it into an analog intermediate frequency signal suitable for acquisition by the AD converter.

[0039] AD converter, used to sample and quantize the analog intermediate frequency signal and convert it into a digital signal suitable for processing by a digital signal processor;

[0040] Digital signal processor, used to determine the maximum and minimum values ​​of the data envelope, used to calculate the low threshold and high threshold based on the maximum and minimum values ​​of the data envelope, used to count the data ratio between the high and low thresholds of the data envelope, used to count the interference type according to the data ratio between the high and low thresholds. Is it pulse interference?

[0041] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0042] (1) The judgment step of the present invention only requires the maximum value, the minimum value and simple calculations, and the calculation is simple.

[0043] (2) The present invention adopts high and low dual threshold judgment, making full use of the characteristic that the envelope samples of pulse interference are concentrated near the maximum and minimum values ​​of the envelope, further improving the recognition accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The present invention is further described in conjunction with the following drawings and embodiments, and all the concepts and innovations of the present invention should be regarded as the disclosed contents and the protection scope of the present invention.

[0045] Figure 1 The present invention discloses a flow chart of a method for pulse interference identification in a satellite navigation receiving device.

[0046] Figure 2 The present invention is a schematic structural diagram of a system for pulse interference identification in a satellite navigation receiving device disclosed in the present invention. DETAILED DESCRIPTION

[0047] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be understood that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, and therefore should not be regarded as limiting the scope of protection. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technical personnel in this field without making creative work are within the scope of protection of the present invention.

[0048] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0049] Embodiment 1:

[0050] A flowchart of a method for pulse interference identification in a satellite navigation receiving device according to this embodiment is shown in FIG. Figure 1As shown, the computational complexity of the entire pulse interference identification process is very low, and only a small amount of calculation and judgment is required. Moreover, the entire pulse interference identification process is completely completed by the device independently, without the need for any human intervention. Compared with the traditional single threshold judgment method, the method of the present invention adopts high and low dual threshold judgments, making full use of the characteristics that the envelope samples of pulse interference are concentrated near the maximum and minimum values ​​of the envelope, further improving the recognition accuracy. The present invention automatically identifies pulse interference based on the data envelope distribution characteristics, overcoming the shortcomings of the prior art such as low recognition accuracy, high implementation complexity or low intelligence, and can be used to provide an important basis for selecting appropriate interference suppression measures for satellite navigation receiving equipment, especially core equipment.

[0051] Embodiment 2:

[0052] This embodiment is further optimized on the basis of Embodiment 1. In this embodiment, the receiving antenna is the first component of the satellite navigation receiving device, which is used to convert the electromagnetic wave signal transmitted by the navigation satellite into a voltage or current signal for the RF channel of the receiving device to capture and process. The RF channel is located between the receiving antenna and the AD converter, and is used to filter, convert and gain control the received RF analog signal, and convert it into an analog intermediate frequency signal suitable for acquisition by the AD converter. The AD converter is used to sample and quantize the analog intermediate frequency signal, and convert it into a digital signal suitable for processing by a digital signal processor. The other parts of this embodiment are the same as Embodiment 1, so they will not be repeated.

[0053] Embodiment 3:

[0054] This embodiment is further optimized on the basis of embodiment 1, and the conjugate function in this embodiment can be replaced, which is a common function in the art and has low computational complexity. The rest of this embodiment is the same as embodiment 1, so it will not be described again.

[0055] Embodiment 4:

[0056] This embodiment is further optimized on the basis of embodiment 1. k The maximum and minimum values ​​range from 0 to 2 b-1In addition, in this embodiment, the quantization word length of the ADC of the navigation receiving device is 10 bits, the sampling rate of the ADC is 16.25MHz, the input signal contains satellite navigation signals, receiver thermal noise and pulse interference, the pulse interference repetition period is 20us, the duty cycle is 30%, and the pulse interference power is 10dB greater than the thermal noise power. The data length N used for pulse interference identification is 1625 (i.e., 0.1ms data). Through the method of the present invention, the maximum value of the data envelope is 285, the minimum value is 1, and then the low threshold is 57, the high threshold is 228, the number of data between the high and low thresholds K is 142, and the data proportion r is 8.72%, which is less than 20%, so it is correctly identified as pulse interference.

[0057] The other parts of this embodiment are the same as those of Embodiment 1, and thus will not be described in detail.

[0058] Embodiment 5:

[0059] This embodiment is further optimized on the basis of embodiment 1. The use of the high threshold and the low threshold is to collect the statistical data envelope y. k How many are greater than the lower threshold and less than the upper threshold.

[0060] The other parts of this embodiment are the same as those of Embodiment 1, and thus will not be described in detail.

[0061] Embodiment 6:

[0062] This embodiment is further optimized on the basis of the embodiment 1. In this embodiment, the data ratio r between the high and low thresholds is used to determine whether it is a pulse signal.

[0063] The other parts of this embodiment are the same as those of Embodiment 1, and thus will not be described in detail.

[0064] Embodiment 7:

[0065] This embodiment is further optimized on the basis of embodiment 1. In this embodiment, the input signal includes satellite navigation signal, receiver thermal noise and narrowband interference. The narrowband interference bandwidth is 0.5MHz, the center frequency deviates from the center frequency of the satellite navigation signal by 0.2MHz, and the interference power is 10dB greater than the thermal noise power. Through the method of the present invention, the maximum value of the data envelope is 486, the minimum value is 1, and then the low threshold is 97, the high threshold is 388, the number of data K between the high and low thresholds is 1051, and the data proportion r is 64.68%, which is much greater than 20%, so it is correctly identified as non-pulse interference. For comparison, 1000 repeated experiments were carried out, and the pulse interference was identified by the method of the present invention and the method disclosed in the document "A satellite navigation interference type identification method based on SVM multi-classification algorithm". The method of the present invention only misjudged the above narrowband Gaussian interference as pulse interference twice in 1000 experiments, and the recognition accuracy was 99.8%. The comparison method misjudged the above narrowband Gaussian interference as pulse interference 577 times, and the recognition accuracy was only 42.3%. It is verified that the method of the present invention has a higher recognition accuracy rate than the prior art.

[0066] In this embodiment, if the proportion r of data between the high and low thresholds is less than 20%, it is determined that the interference type received in the satellite navigation receiving device is pulse interference, otherwise it is determined that the interference type is not pulse interference.

[0067] The other parts of this embodiment are the same as those of Embodiment 1, and thus will not be described in detail.

[0068] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for pulse interference identification in a satellite navigation receiving device, characterized in that: The following steps are involved: Step S1. Collecting data from a satellite navigation receiving device, and obtaining a data envelope based on the collected data; Step S2. A digital signal processor in the receiving device determines the maximum and minimum values ​​of the data envelope; Step S3. The digital signal processor in the receiving device calculates the low threshold and the high threshold according to the maximum and minimum values ​​of the data envelope; Step S4. The digital signal processor in the receiving device calculates the proportion of data between the high and low thresholds of the data envelope; Step S5. The digital signal processor in the receiving device counts the interference type as pulse interference according to the data ratio between the high and low thresholds; The step S4 comprises: Statistical data envelope y k Satisfied z L < y k < z H The number of data is recorded as K ; Data ratio between high and low thresholds r The formula is r = K / N ; in, z L is the low threshold, z H is the high threshold, N The number of collected data.

2. A method for pulse interference identification in a satellite navigation receiving device according to claim 1, characterized in that , the step S1 includes: receiving the electromagnetic wave signal transmitted by the navigation satellite according to the receiving antenna in the receiving device, and converting the electromagnetic wave signal into a radio frequency analog signal; transmitting the radio frequency analog signal to the radio frequency channel for filtering, frequency conversion and gain control, and converting it into an analog intermediate frequency signal; sampling and quantizing the analog intermediate frequency signal, converting it into a digital signal, and transmitting it to a digital signal processor.

3. The method for pulse interference identification in a satellite navigation receiving device according to claim 1, characterized in that , the step S1 also includes: by collecting data, obtaining N data, and setting them as x1, x2, x3, ..., xN; according to the preset N data, the formula for obtaining the data packet is: ； in, y k is the data envelope, function conj(·) is the conjugate function, N is the number of collected data, which is a positive integer.

4. The method for pulse interference identification in a satellite navigation receiving device according to claim 1, characterized in that: The step S2 includes: Data envelope y k The formula for the maximum value of is , k=1,2,..., N ; Data Envelope y k The formula for the minimum value of is , k=1,2,...,N; wherein the function max(·) represents the maximum value, and the function min(·) represents the minimum value.

5. The method for pulse interference identification in a satellite navigation receiving device according to claim 4, characterized in that: The step S3 includes: The formula of the lower threshold is: ; The formula for the high threshold is .

6. The method for pulse interference identification in a satellite navigation receiving device according to claim 1, characterized in that: The step S5 includes: presetting a data threshold between the upper and lower thresholds, determining whether the data ratio between the upper and lower thresholds is less than or equal to the threshold, if so, determining that the interference type received in the satellite navigation receiving device is pulse interference, if not, determining that the interference type received in the satellite navigation receiving device is not pulse interference.

7. A system for pulse interference identification in a satellite navigation receiving device, characterized in that: It includes a receiving device, a radio frequency channel, an AD converter and a digital signal processor, wherein: the receiving device, the receiving antenna in the receiving device is used to collect data, and is used to convert the electromagnetic wave signal transmitted by the navigation satellite received into a voltage or current signal for the radio frequency channel of the receiving device to collect and process, and is used to obtain a data envelope according to the collected data; The RF channel is located between the receiving antenna and the AD converter and is used to filter, convert and gain-control the received RF analog signal and convert it into an analog intermediate frequency signal suitable for acquisition by the AD converter. The AD converter is used to sample and quantize the analog intermediate frequency signal and convert it into a digital signal suitable for processing by a digital signal processor; the digital signal processor is used to determine the maximum and minimum values ​​of the data envelope, to calculate the low threshold and the high threshold according to the maximum and minimum values ​​of the data envelope, to calculate the data ratio between the high and low thresholds of the data envelope, and to count the interference type according to the data ratio between the high and low thresholds to determine whether it is pulse interference; Statistical data envelope y k Satisfied z L < y k < z H The number of data is recorded as K ; Data ratio between high and low thresholds r The formula is r = K / N ; in, z L is the low threshold, z H is the high threshold, N The number of collected data.

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