CN115102564B - A kind of AGC control method based on spectrum scanning data - Google Patents

Abstract

The present invention discloses an AGC control method based on spectrum scanning data, which inputs spectrum scanning data and parameters, segments the spectrum scanning data, calculates the energy and the maximum value of each segment, compares the maximum value with the threshold value, and determines whether the maximum value is greater than the threshold value. If it is less than the threshold value, save this frame of data for subsequent calculations, and repeat the above steps; if it is greater than the threshold value, discard the current frame of data, and control the attenuator to increase one gear, and repeat the above steps; if the attenuation value is stable, maintain the value for x minutes to perform spectrum scanning and save the data, then reset the attenuator to 0, and repeat the above steps. The present invention adopts a software control method, and for a receiver without an AGC function, there is no need to change the hardware, the structure is simple and easy to implement, and the operation efficiency is high. In a complex electromagnetic environment, it can quickly adapt to the environment, ensure the correctness of the spectrum scanning data under large signal interference, and provide support for subsequent data calculation and analysis.

Description

A kind of AGC control method based on spectrum scanning data

Technical Field

The present invention relates to the field of radio monitoring technology, and in particular to an AGC control method based on spectrum scanning data.

Background Art

With the development of communication technology, communication services are increasing and the electromagnetic environment is becoming more and more complex. Monitoring equipment usually uses digital broadband receivers with limited dynamic range, which are easily saturated by large signal interference in complex environments. For broadband receivers without AGC function, the collected data may be incorrect in complex environments, resulting in subsequent analysis and decision errors. Therefore, being able to control AGC with software based on spectrum scanning data is of great significance to radio monitoring.

Summary of the invention

The object of the present invention is to provide a software AGC control method based on spectrum scanning data, which is used to solve the problem that a broadband receiver without AGC function cannot work normally under large signal interference.

The present invention achieves the above-mentioned purpose through the following technical solutions:

An AGC control method based on spectrum scanning data comprises the following steps:

Step S1: Collect spectrum scanning data and obtain scanning parameters, including intermediate frequency bandwidth IFBw, starting frequency startF, cutoff frequency stopF and scanning step stepF; intermediate frequency bandwidth (IFBW) refers to the bandwidth of the intermediate frequency filter inside the network analyzer receiver. Setting IFBW generally requires balancing the two factors of dynamic range and measurement speed. The wider the IFBW is set, the more noise enters the receiver, the higher the noise floor, the smaller the dynamic range (the difference between the maximum port output power and the noise floor), and the greater the trace noise; setting a narrower IFBW can improve the noise floor, dynamic range and trace noise, but the scanning speed will also be slower. This is because the narrower the filter bandwidth, the higher the order required to achieve it, the more sampling points, and the slower the speed.

Step S2: Segment the spectrum scanning data according to the intermediate frequency bandwidth, namely:

Step S3: For each segment of the spectrum scanning data, calculate the energy sum, which is recorded as:

Wherein, _Levi is the level value of the ith spectrum scanning data in the segment, in dBuv; M is the number of spectrum scanning data contained in each segment;

Step S4: Find the data segment with the maximum energy sum, denoted as P _max ;

Step S5: estimating an energy threshold P _threshold according to the intermediate frequency bandwidth IFBw and the scanning step stepF;

Step S6: Determine whether P _max is greater than an energy threshold P _threshold ;

Step S7: When the attenuation value is stable, maintain the value for x minutes (x is adjustable, x=1 by default), then reset the attenuator to 0, and repeat steps S1 to S7.

A further solution is that in step S5, the energy threshold P _threshold is calculated as follows:

Step S51: Calculate the maximum value of IQ data according to the number of A/D bits k of the receiver:

IQ _max = 2 ^k -1

Step S52: Calculate the number of points nFFT used for FFT calculation according to the intermediate frequency bandwidth IFBw and the scanning step stepF. nFFT needs to satisfy:

nFFT>n1,nFFT＝2 ^m

Where n1 = IFBW/stepF;

Step S53: construct intermediate frequency data X:

Idata＝[I ₀ ,I ₁ ,…,I _nFFT-1 ], I ₀ ＝I ₁ ＝…＝I _nFFT-1 ＝IQ _max

X = hilbert(Idata)

Step S54: Perform Fourier transform on the intermediate frequency data X, which is expressed as:

Step S55: Calculate the Ss band energy and _Ps :

Wherein, cutN＝(nFFT-n1)/2;

Step S56: Calculate the energy threshold P _threshold =0.9*P _s .

A further solution is that in step S6, the step of determining whether P _max is greater than an energy threshold P _threshold is as follows:

Step S61: If P _max <P _threshold , save this frame of data for subsequent calculations, and repeat steps S1 to S6;

Step S62: If P _max ≥ P _threshold , discard the data of the current frame, control the attenuator to increase by one level, and repeat steps S1 to S6.

The beneficial effects of the present invention are:

The AGC control method based on spectrum scanning data of the present invention adopts software control mode. For a receiver without AGC function, there is no need to change the hardware. The structure is simple and easy to implement, and the operation efficiency is high. In a complex electromagnetic environment, the method can quickly adapt to the environment, ensure the correctness of the spectrum scanning data under large signal interference, and provide support for subsequent data calculation and analysis.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

Fig. 1 is a flow chart of the present invention.

DETAILED DESCRIPTION

To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

In any embodiment, as shown in FIG1 , an AGC control method based on spectrum scanning data of the present invention comprises the following steps:

Step S1: Collect spectrum scanning data and obtain scanning parameters, including intermediate frequency bandwidth IFBw, starting frequency startF, cutoff frequency stopF and scanning step stepF;

Step S2: Segment the spectrum scanning data according to the intermediate frequency bandwidth, namely:

Step S3: For each segment of the spectrum scanning data, calculate the energy sum, which is recorded as:

Wherein, _Levi is the level value of the ith spectrum scanning data in the segment, in dBuv; M is the number of spectrum scanning data contained in each segment;

Step S4: Find the data segment with the maximum energy sum, denoted as P _max ;

Step S5: Estimate the energy threshold P _threshold according to the intermediate frequency bandwidth IFBw and the scanning step stepF:

Step S51: Calculate the maximum value of IQ data according to the number of A/D bits k of the receiver:

IQ _max = 2 ^k -1

Step S52: Calculate the number of points nFFT used for FFT calculation according to the intermediate frequency bandwidth IFBw and the scanning step stepF. nFFT needs to satisfy:

nFFT>n1,nFFT＝2 ^m

Where n1 = IFBW/stepF;

Step S53: construct intermediate frequency data X:

Idata＝[I ₀ ,I ₁ ,…,I _nFFT-1 ], I ₀ ＝I ₁ ＝…＝I _nFFT-1 ＝IQ _max

X = hilbert(Idata)

Step S54: Perform Fourier transform on the intermediate frequency data X, which is expressed as:

Step S55: Calculate the Ss band energy and _Ps :

Wherein, cutN＝(nFFT-n1)/2;

Step S56: Calculate the threshold value P _threshold =0.9*P _s ;

Step S6: Determine whether P _max is greater than a threshold:

Step S61: If P _max <P _threshold , save this frame of data for subsequent calculations, and repeat steps S1 to S6;

Step S62: if P _max ≥ P _threshold , discard the current frame data, control the attenuator to increase one level, and repeat steps S1 to S6;

Step S7: When the attenuation value is stable, maintain the value for x minutes (x is adjustable, x=1 by default), then reset the attenuator to 0, and repeat steps S1 to S7.

In a specific embodiment, as shown in FIG1 , an AGC control method based on spectrum scanning data of the present invention comprises the following steps:

1. The receiver collects spectrum scanning data and obtains scanning parameters, specifically, IFBw = 40MHz, startF = 1GHz, stopF = 3GHz, stepF = 25kHz;

2. Segment the spectrum scan data, segN=50;

3. Calculate the energy and of each segment of the spectrum scanning data;

4. Find the data segment with the maximum energy sum, recorded as P _max ;

5. Estimate the energy threshold P _threshold . For a 14-bit A/D, IQ _max = 16383, nFFT = 2048. After constructing the intermediate frequency IQ data, perform Fourier transform, calculate the in-band energy sum, and take 90% of it as the threshold.

6. Determine whether P _max is greater than the threshold. If it is less than the threshold, save this frame of data for subsequent calculations and repeat the above steps. If it is greater than the threshold, discard this frame of data and control the attenuator to increase one gear and repeat the above steps.

7. If the attenuation value is stable, maintain the value for 1 minute to perform spectrum scanning and save the data, then reset the attenuator to 0 and repeat the above steps.

The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further explain various possible combinations. In addition, the various different embodiments of the present invention can also be combined arbitrarily, as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims (1)

1. An AGC control method based on spectrum scanning data, characterized in that it comprises the following steps: Step S1: Collect spectrum scanning data and obtain scanning parameters, including intermediate frequency bandwidth IFBw, starting frequency startF, cutoff frequency stopF and scanning step stepF; Step S2: Segment the spectrum scanning data according to the intermediate frequency bandwidth, namely: Step S3: For each segment of the spectrum scanning data, calculate the energy sum, which is recorded as: Wherein, _Levi is the level value of the ith spectrum scanning data in the segment, in dBuv; M is the number of spectrum scanning data contained in each segment; Step S4: Find the data segment with the maximum energy sum, denoted as P _max ; Step S5: estimating an energy threshold P _threshold according to the intermediate frequency bandwidth IFBw and the scanning step stepF; In step S5, the energy threshold P _threshold is calculated as follows: Step S51: Calculate the maximum value of IQ data according to the number of A/D bits k of the receiver: IQ _max = 2 ^k -1 Step S52: Calculate the number of points nFFT used for FFT calculation according to the intermediate frequency bandwidth IFBw and the scanning step stepF. nFFT needs to satisfy: nFFT＞n1，nFFT＝2 ^m Where n1 = IFBW/stepF; Step S53: construct intermediate frequency data X: Idata=[I ₀ , I ₁ ,..., _InFFT-1 ], I ₀ =I ₁ =...= _InFFT-1 =IQ _max X = hilbert(Idata) Step S54: Perform Fourier transform on the intermediate frequency data X, which is expressed as: Step S55: Calculate the Ss band energy and _Ps : Wherein, cutN＝(nFFT-n1)/2; Step S56: Calculate the energy threshold P _rhreshold =0.9*P _s ; Step S6: Determine whether P _max is greater than an energy threshold P _threshold ; In step S6, the steps of judging whether P _max is greater than the energy threshold P _threshold are as follows: Step S61: if P _max < P _threshold , save this frame of data for subsequent calculations, and repeat steps S1 to S6; Step S62: if P _max ≥ P _threshold , discard the current frame data, control the attenuator to increase one level, and repeat steps S1 to S6; Step S7: When the attenuation value is stable, maintain the value for x minutes, reset the attenuator to 0, and repeat steps S1 to S7.