Broadcast signal broadband sorting method and system

Abstract

The invention provides a broadcast signal broadband sorting method, which comprises the following steps of: S1, collecting signal spectrum data in a preset filtering range for multiple times, and setting a self-adaptive threshold; s2, de-noising the signals according to the self-adaptive threshold, and dividing the de-noised signals into signals containing carrier waves and signals not containing carrier waves; s3, analog broadcast signal sorting is carried out on the signals containing the carriers, and analog broadcast signals are output; and S4, carrying out digital amplitude modulation broadcast signal sorting on the signal without the carrier, and outputting a digital broadcast signal. According to actual electromagnetic environment conditions, broadcast signal features are combined, the broadcast signal sorting process is simplified, and the broadcast signal sorting rate is improved under the condition that the recognition rate is not reduced.

Description

Technical Field

[0001] The present invention relates to the field of electronic information technology, and in particular to a method and system for broadband sorting of broadcast signals. Background Art

[0002] The signal monitoring system uses antennas and monitoring equipment to receive electromagnetic environment data in the air, and uses digital signal processing to implement sampling, mixing, digital filtering and other processing to obtain the original IQ data within the monitoring bandwidth. Based on the original IQ data, various subsequent statistical, analytical and other operations can be performed to obtain the final monitoring target.

[0003] Broadcast signal monitoring is an automatic monitoring method for the broadcasting of broadcast signals in the medium and short wave bands, and it helps to understand the usage of broadcast signals in the medium and short wave bands. Currently, broadcast signals in the medium and short wave bands include both analog signals and digital signals. The analog broadcast signals in the medium and short wave bands use amplitude modulation (AM), and the digital broadcast signals are digital radio mondiale (DRM), which uses OFDM (Orthogonal Frequency Division Multiplexing) modulation to combat signal fading. Since the medium and short wave bands have the characteristics of long propagation distance, there are a large number of military and civilian signals in the bands, resulting in an extremely complex electromagnetic environment.

[0004] When low-cost, miniaturized equipment is used, the equipment generally does not have multi-channel DDC capabilities, and broadcast signal monitoring will use a combination of broadband monitoring and sorting and narrowband time-sharing identification. This time-sharing monitoring and identification method is very inefficient and cannot meet the timeliness requirements of automatic monitoring of broadcast signals.

[0005] like Figure 3 As shown, the general process of the broadcast signal monitoring method is a method of combining broadband detection with multi-channel narrowband monitoring and identification. First, the broadband monitoring data is used to sort the signals to obtain a signal table, including the center frequency and bandwidth of each signal; then, the signals are allocated in sequence according to the number of multi-channel DDCs of the monitoring equipment to achieve narrowband measurement of the signals in the signal table and identify analog broadcast and digital amplitude modulation signals.

[0006] At present, the commonly used broadcast signal monitoring method is a method of combining broadband detection with multi-channel narrowband monitoring and identification. Among them, the broadband detection method generally adopts broadband statistical spectrum and adaptive threshold comparison method. The sampling points that are continuously higher than the threshold are merged into one signal, and the center position of the continuous sampling points is taken as the signal center frequency, and the width of the continuous sampling points is taken as the signal bandwidth, such as CN201910494434 A real-time threshold signal detection method and CN201910285265 Ultra-short wave full-band signal sorting method; the narrowband monitoring and identification method of broadcast signals includes two types: analog broadcast identification and DRM signal identification, AM modulation Signal recognition methods mostly use statistical instantaneous feature recognition, including the instantaneous amplitude sequence, frequency sequence, instantaneous amplitude peak and peak-to-average ratio, instantaneous frequency peak and peak-to-average ratio of the signal, and then use decision trees for recognition, such as CN202011284064, a method for identifying analog signals in the air based on instantaneous features; DRM signals generally use autocorrelation to detect the cyclic prefix of OFDM, and then compare the length of the cyclic prefix in different modes specified by the DRM protocol for recognition, such as CN202111509471, a method for identifying DRM signals in non-ideal channels based on autocorrelation. Due to the complex electromagnetic environment of the medium and short wave frequency bands, many signals are sorted out. The combination of wide and narrow bands requires high computing power for the monitoring equipment. When low-cost, miniaturized equipment is used, the efficiency of automatic monitoring of broadcast signals is very low.

[0007] Therefore, a method for broadband sorting of broadcast signals with simple structure and high efficiency is needed. Summary of the invention

[0008] In view of the defects in the prior art, an object of the present invention is to provide a method and system for broadband sorting of broadcast signals.

[0009] A method for broadband sorting of broadcast signals provided by the present invention comprises:

[0010] Step S1: Collect signal spectrum data within a preset filtering range multiple times and set an adaptive threshold;

[0011] Step S2: De-noising the signal according to the adaptive threshold, and dividing the de-noised signal into a signal containing a carrier and a signal without a carrier;

[0012] Step S3: sorting the signal containing the carrier into analog broadcast signals, and outputting the analog broadcast signals;

[0013] Step S4: sorting the digital AM broadcast signal from the signal without carrier wave, and outputting the digital broadcast signal.

[0014] Preferably, the step S1 comprises:

[0015] Step S1.1: Collect signal spectrum data within a preset filtering range N times;

[0016] Step S1.2: Calculate the mean spectrum value meanSpec of the i-th frequency point i , maximum spectrum value maxSpec i and the minimum spectrum value minSpec i ;

[0017]

[0018] maxSpeci i =MAX(spec j,i )

[0019] minSpec i =MIN(spec j,i )

[0020] spec j,i Indicates the value of the i-th frequency point of the j-th spectrum acquisition;

[0021] Step S1.3: Obtain a basic threshold BasicTh by performing windowed median filtering on the minimum spectrum value;

[0022] Step S1.4: Set the floating threshold addTh. Specifically, the average change between the maximum spectrum value and the minimum spectrum value is used as the floating threshold:

[0023]

[0024] Wherein, M represents the number of frequency points in a full-band spectrum frame;

[0025] Step S1.5: Set the adaptive threshold FinalTh to:

[0026] FinalTh=BasicTh+addTh.

[0027] Preferably, the step S2 comprises:

[0028] Step S2.1: De-noise the collected signal; specifically, by using the mean spectrum value meanSpec i Compared with the adaptive threshold, the mean spectrum value meanSpec i The frequency points that are greater than the adaptive threshold are marked as signal frequencies, otherwise they are marked as noise frequencies and removed;

[0029] Step S2.2: When two or more consecutive frequency points are marked as signal frequency points, the consecutive frequency points are recorded as a basic signal, and the nth basic signal is BS. n, the starting frequency of the basic signal BS n1 and cutoff frequency BS n2 ;

[0030] Step S2.3: According to a preset rule, the basic signal is classified into a signal containing a carrier and a signal without a carrier.

[0031] Preferably, the step S2.3 comprises:

[0032] Step S2.3.1: In BS n1 to BS n2 The minimum value of the mean spectrum value is minV, and the basic signal is preprocessed to obtain the preprocessed basic signal set

[0033] Representative from BS n1 to BS n2 The set of mean spectrum values ​​of ;

[0034] Step S2.3.2: BS n The maximum value in Proc is recorded as MaxS, the maximum value position is MaxIndex, and the second largest value is MaxS2;

[0035] Step S2.3.3: When MaxS is greater than 2 times of MaxS2 or greater than (MaxS2+10dB), it contains a carrier, and the corresponding signal is a signal containing a carrier; otherwise, it does not contain a carrier, and the corresponding signal is a signal without a carrier.

[0036] Preferably, step S3 comprises:

[0037] Step S3.1: The signal containing the carrier is judged for spectrum symmetry. If it is symmetrical, it is marked as an analog broadcast signal and the process goes to step S3.2. If it is asymmetrical, other signals are directly output.

[0038] Step S3.2: Output an analog broadcast signal, wherein the center frequency of the signal is the frequency corresponding to the MaxIndex position, and the bandwidth is 2 times Max (MaxIndex-BS n1 , B.S. n1 -MaxIndex).

[0039] Preferably, the step S3.1 comprises:

[0040] Step S3.1.1: Calculate BS n Proc based on MaxIndex spectrum symmetry value P:

[0041]

[0042] x represents the spectrum position;

[0043] Where B = 2*min(MaxIndex-BS n1 , B.S. n2 -MaxIndex);

[0044] Step S3.1.2: When P ≥ 0.85, the spectrum is a symmetrical spectrum, otherwise it is an asymmetrical spectrum.

[0045] Preferably, step S4 comprises:

[0046] Step S4.1: In a signal without a carrier, the bandwidth when the peak value of the spectrum drops to the preset spectrum minimum value is BW min , when the peak value of the spectrum drops to the preset maximum value of the spectrum, the bandwidth is BW max ;

[0047] Step S4.2: Setting the rectangular coefficient RectCoef of the basic signal spectrum;

[0048]

[0049] Step S4.3: If the rectangular coefficient RectCoef is greater than 0.85, the corresponding signal is a digital modulation signal;

[0050] Step S4.4: Determine the BW corresponding to the digital modulation signal max Whether the preset bandwidth standard is met, if so, it is marked as a digital AM broadcast signal and the process goes to step S4.5; if not, other signals are directly output;

[0051] Step S4.5: Output digital broadcast signal, the center frequency of the signal is BW max The frequency corresponding to the middle position, the bandwidth is BW max .

[0052] A broadcast signal broadband sorting system provided according to the present invention comprises:

[0053] Module M1: collects signal spectrum data within a preset filtering range multiple times and sets an adaptive threshold;

[0054] Module M2: denoises the signal according to the adaptive threshold, and divides the denoised signal into a signal containing a carrier and a signal without a carrier;

[0055] Module M3: sorting analog broadcast signals from signals containing carrier waves and outputting analog broadcast signals;

[0056] Module M4: sorts digital AM broadcast signals from signals without carrier waves and outputs digital broadcast signals.

[0057] Preferably, the module M1 comprises:

[0058] Module M1.1: collects signal spectrum data within a preset filtering range N times;

[0059] Module M1.2: Calculate the mean spectrum value meanSpec of the i-th frequency point i , maximum spectrum value maxSpec i and the minimum spectrum value minSpec i ;

[0060]

[0061] maxSpec i =MAX(spec j,i )

[0062] minSpec i =MIN(spec j,i )

[0063] spec j,i Indicates the value of the i-th frequency point of the j-th spectrum acquisition;

[0064] Module M1.3: Obtain the basic threshold BasicTh by performing windowed median filtering on the minimum spectrum value;

[0065] Module M1.4: Set the floating threshold addTh. Specifically, the average change between the maximum spectrum value and the minimum spectrum value is used as the floating threshold:

[0066]

[0067] Wherein, M represents the number of frequency points in a full-band spectrum frame;

[0068] Module M1.5: Set the adaptive threshold FinalTh to:

[0069] FinalTh=BasicTh+addTh;

[0070] The module M2 comprises:

[0071] Module M2.1: De-noise the collected signal; specifically, through the mean spectrum value meanSpec i Compared with the adaptive threshold, the mean spectrum value meanSpec i The frequency points that are greater than the adaptive threshold are marked as signal frequencies, otherwise they are marked as noise frequencies and removed;

[0072] Module M2.2: When two or more consecutive frequencies are marked as signal frequencies, the consecutive frequencies are recorded as a basic signal, and the nth basic signal is BS. n , the starting frequency of the basic signal BS n1 and cutoff frequency BS n2 ;

[0073] Module M2.3: Classify the basic signals into signals with carriers and signals without carriers according to preset rules;

[0074] The module M2.3 includes:

[0075] Module M2.3.1: In BS n1 to BS n2 The minimum value of the mean spectrum value is minV, and the basic signal is preprocessed to obtain the preprocessed basic signal set

[0076] Representative from BS n1 to BS n2 The set of mean spectrum values ​​of ;

[0077] Module M2.3.2: BS n The maximum value in Proc is recorded as MaxS, the maximum value position is MaxIndex, and the second largest value is MaxS2;

[0078] Module M2.3.3: When MaxS is greater than 2 times of MaxS2 or greater than (MaxS2+10dB), it contains a carrier and the corresponding signal is a signal containing a carrier; otherwise, it does not contain a carrier and the corresponding signal is a signal without a carrier.

[0079] Preferably, the module M3 includes:

[0080] Module M3.1: The signal containing the carrier is judged for spectrum symmetry. If it is symmetrical, it is marked as an analog broadcast signal and enters module M3.2; if it is asymmetrical, other signals are directly output;

[0081] Module M3.2: Output analog broadcast signal, where the center frequency of the signal is the frequency corresponding to the MaxIndex position, and the bandwidth is 2 times Max (MaxIndex-BS n1 , B.S. n1 -MaxIndex).

[0082] The module M3.1 includes:

[0083] Module M3.1.1: Computing BS n Proc based on MaxIndex spectrum symmetry value P:

[0084]

[0085] x represents the spectrum position;

[0086] Where B = 2*min(MaxIndex-BS n1 , B.S. n2 -MaxIndex);

[0087] Module M3.1.2: When P ≥ 0.85, the spectrum is a symmetrical spectrum, otherwise it is an asymmetrical spectrum;

[0088] The module M4 comprises:

[0089] Module M4.1: In a signal without a carrier, the bandwidth when the peak value of the spectrum drops to the preset spectrum minimum value is BW min , when the peak value of the spectrum drops to the preset maximum value of the spectrum, the bandwidth is BW max ;

[0090] Module M4.2: Set the rectangular coefficient RectCoef of the basic signal spectrum;

[0091]

[0092] Module M4.3: If the rectangular coefficient RectCoef is greater than 0.85, the corresponding signal is a digital modulation signal;

[0093] Module M4.4: Determine the BW corresponding to the digital modulation signal max Whether the preset bandwidth standard is met, if so, it is marked as a digital AM broadcast signal and enters module M4.5; if not, other signals are directly output;

[0094] Module M4.5: Output digital broadcast signal, the center frequency of the signal is BW max The frequency corresponding to the middle position, the bandwidth is BW max .

[0095] Compared with the prior art, the present invention has the following beneficial effects:

[0096] 1. The present invention can reduce the computational requirements for broadcast signal monitoring equipment, and only needs to have a broadband monitoring function, and does not require a multi-channel digital down-conversion function, so that the sorting effect can still be achieved while simplifying the equipment structure;

[0097] 2. The present invention simplifies the broadcast signal sorting process according to the actual electromagnetic environment and combines the broadcast signal characteristics, and improves the broadcast signal sorting rate without reducing the recognition rate;

[0098] 3. The present invention obtains a shortwave adaptive noise threshold based on the median filtering of the broadband spectrum and the statistical method of the spectrum fluctuation range, realizes fully automatic noise threshold estimation, can adapt to a variety of application scenarios, and improves the accuracy of signal sorting;

[0099] 4. The present invention realizes rapid identification of shortwave frequency band analog and digital broadcast signals by using a statistical algorithm of broadcast signal frequency domain characteristics based on spectrum data and a carrier detection algorithm and a rectangular coefficient statistical algorithm. BRIEF DESCRIPTION OF THE DRAWINGS

[0100] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0101] Figure 1 It is a flow chart of the method for broadband sorting of broadcast signals of the present invention;

[0102] Figure 2 This is a flow chart of a broadband sorting algorithm for broadcast signals according to Embodiment 2 of the present invention;

[0103] Figure 3 The figure is a flow chart of a broadband sorting method for broadcast signals in the background technology. DETAILED DESCRIPTION

[0104] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0105] Example 1

[0106] A method for broadband sorting of broadcast signals, comprising:

[0107] Step S1: Collect signal spectrum data within a preset filtering range multiple times and set an adaptive threshold;

[0108] Step S2: De-noising the signal according to the adaptive threshold, and dividing the de-noised signal into a signal containing a carrier and a signal without a carrier;

[0109] Step S3: sorting the signal containing the carrier into analog broadcast signals, and outputting the analog broadcast signals;

[0110] Step S4: sorting the digital AM broadcast signal from the signal without carrier wave, and outputting the digital broadcast signal.

[0111] Specifically, the step S1 includes:

[0112] Step S1.1: Collect signal spectrum data within a preset filtering range N times;

[0113] Step S1.2: Calculate the mean spectrum value meanSpec of the i-th frequency point i , maximum spectrum value maxSpec i and the minimum spectrum value minSpec i ;

[0114]

[0115] maxSpec i =MAX(spec j,i )

[0116] minSpec i =MIN(spec j,i )

[0117] spec j,i Indicates the value of the i-th frequency point of the j-th spectrum acquisition;

[0118] Step S1.3: Obtain a basic threshold BasicTh by performing windowed median filtering on the minimum spectrum value;

[0119] Step S1.4: Set the floating threshold addTh. Specifically, the average change between the maximum spectrum value and the minimum spectrum value is used as the floating threshold:

[0120]

[0121] Wherein, M represents the number of frequency points in a full-band spectrum frame;

[0122] Step S1.5: Set the adaptive threshold FinalTh to:

[0123] FinalTh=BasicTh+addTh.

[0124] Specifically, step S2 includes:

[0125] Step S2.1: De-noise the collected signal; specifically, by using the mean spectrum value meanSpec i Compared with the adaptive threshold, the mean spectrum value meanSpec i The frequency points that are greater than the adaptive threshold are marked as signal frequencies, otherwise they are marked as noise frequencies and removed;

[0126] Step S2.2: When two or more consecutive frequency points are marked as signal frequency points, the consecutive frequency points are recorded as a basic signal, and the nth basic signal is BS. n, the starting frequency of the basic signal BS n1 and cutoff frequency BS n2 ;

[0127] Step S2.3: According to a preset rule, the basic signal is classified into a basic signal containing a carrier and a basic signal without a carrier.

[0128] Specifically, step S2.3 includes:

[0129] Step S2.3.1: In BS n1 to BS n2 The minimum value of the mean spectrum value is minV, and the basic signal is preprocessed to obtain the preprocessed basic signal set

[0130] Representative from BS n1 to BS n2 The set of mean spectrum values ​​of ;

[0131] Step S2.3.2: BS n The maximum value in Proc is recorded as MaxS, the maximum value position is MaxIndex, and the second largest value is MaxS2;

[0132] Step S2.3.3: When MaxS is greater than 2 times of MaxS2 or greater than (MaxS2+10dB), it contains a carrier, and the corresponding signal is a signal containing a carrier; otherwise, it does not contain a carrier, and the corresponding signal is a signal without a carrier.

[0133] Specifically, step S3 includes:

[0134] Step S3.1: The signal containing the carrier is judged for spectrum symmetry. If it is symmetrical, it is marked as an analog broadcast signal and the process goes to step S3.2. If it is asymmetrical, other signals are directly output.

[0135] Step S3.2: Output an analog broadcast signal, wherein the center frequency of the signal is the frequency corresponding to the MaxIndex position, and the bandwidth is 2 times Max (MaxIndex-BS n1 , B.S. n1 -MaxIndex).

[0136] Specifically, the step S3.1 includes:

[0137] Step S3.1.1: Calculate BS n Proc based on MaxIndex spectrum symmetry value P:

[0138]

[0139] x represents the spectrum position;

[0140] Where B = 2*min(MaxIndex-BS n1 , B.S. n2 -MaxIndex);

[0141] Step S3.1.2: When P ≥ 0.85, the spectrum is a symmetrical spectrum, otherwise it is an asymmetrical spectrum.

[0142] Specifically, step S4 includes:

[0143] Step S4.1: In a signal without a carrier, the bandwidth when the peak value of the spectrum drops to the preset spectrum minimum value is BW min , when the peak value of the spectrum drops to the preset maximum value of the spectrum, the bandwidth is BW max ;

[0144] In a preferred embodiment, the preset minimum spectrum value is 3 dB, and the preset maximum spectrum value is 10 dB.

[0145] Step S4.2: Setting the rectangular coefficient RectCoef of the basic signal spectrum;

[0146]

[0147] Step S4.3: If the rectangular coefficient RectCoef is greater than 0.85, the corresponding signal is a digital modulation signal;

[0148] Step S4.4: Determine the BW corresponding to the digital modulation signal max Whether the preset bandwidth standard is met, if so, it is marked as a digital AM broadcast signal and the process goes to step S4.5; if not, other signals are directly output;

[0149] Step S4.5: Output digital broadcast signal, the center frequency of the signal is BW max The frequency corresponding to the middle position, the bandwidth is BW max .

[0150] Example 2

[0151] The broadband sorting method of broadcast signals of the present invention comprises the following steps:

[0152] Step 1: Start the receiver to conduct uninterrupted spectrum data monitoring of the full frequency band of medium and short waves, with a spectrum resolution of less than 500Hz;

[0153] Step 2: Set the statistical time to 1 second, accumulate the multi-frame full-band spectrum data within the statistical time, and calculate the mean spectrum meanSpec, the maximum spectrum maxSpec, and the minimum spectrum minSpec:

[0154]

[0155] maxSpec i =MAX(spec j,i )

[0156] minSpec i =MIN(spec j,i )

[0157] Among them, meanSpec i represents the mean spectrum value of the i-th frequency point, i represents the i-th frequency point;

[0158] spec j,i Represents the value of the i-th frequency point of the j-th instantaneous spectrum;

[0159] N is the cumulative number of frames;

[0160] maxSpec i Indicates the maximum spectrum value of the i-th frequency point;

[0161] MAX means comparison operation, taking the maximum value;

[0162] minSpec i Indicates the minimum spectrum value of the i-th frequency point;

[0163] MIN means comparison operation, taking the minimum value;

[0164] Step 3: Perform windowed median filtering on the minimum spectrum minSpec to obtain the basic threshold BasicTh. The window function width is set to be slightly larger than 2 times the target signal width. The bandwidth of the analog signal is about 6kHz, and the bandwidth of the digital broadcast signal is 10kHz, so the window function width is set to 20kHz.

[0165] Step 4: Count the floating threshold value addTh, and calculate the average change of the peak spectrum and the minimum spectrum as the floating threshold:

[0166]

[0167] Wherein, M represents the number of frequency points in a full-band spectrum frame;

[0168] Step 5: Calculate the adaptive threshold FinalTh. The basic threshold is added to the floating threshold value to obtain the final adaptive threshold:

[0169] FinalTh=BasicTh+addTh

[0170] Step 6: Compare the average spectrum meanSpec of each frequency point with the adaptive threshold FinalTh. If the average spectrum is higher than the adaptive threshold, it is marked as a signal frequency point, otherwise it is marked as a noise frequency point;

[0171] Step 7: The signals that are continuously marked as signal frequency points are counted as a basic signal BasicSignal, and their starting frequency BS1 and cutoff frequency BS2 are recorded;

[0172] Step 8: Perform analog broadcast signal identification and sorting on the basic signal, as follows:

[0173] Step 81: Determine whether the basic signal contains a carrier. The specific method is as follows:

[0174] Step 811: Count the minimum value minV of the average spectrum meanSpec between BS1 and BS2, and the average spectrum of the basic signal preprocessing

[0175] Step 812: Count the maximum value of BSProc as MaxS, the position as MaxIndex, and the second largest value MaxS2;

[0176] Step 813: When MaxS is greater than 2 times of MaxS2 or MaxS is greater than MaxS2+10dB, there is a carrier, otherwise there is no carrier;

[0177] Step 82: When the basic signal contains a carrier, the spectrum symmetry is statistically analyzed. The specific method is as follows:

[0178] Step 821: BSProc counts the energy ratio of the same width B on both sides of MaxIndex based on the spectrum symmetry P of MaxIndex:

[0179]

[0180] Wherein, B = 2*min(MaxIndex-BS1, BS2-MaxIndex), when B < 3KHz, then B = 3kHz bandwidth;

[0181] Step 822: When P ≥ 0.85, the spectrum is a symmetrical spectrum, otherwise it is an asymmetrical spectrum;

[0182] Step 83: If there is a carrier and the spectrum is symmetrical, it is marked as an analog broadcast signal;

[0183] Step 84: The center frequency of the simulated broadcast signal is the position of the maximum value MaxIndex of the basic signal mean spectrum, and the bandwidth is 2 times Max(MaxIndex-BS1, BS2-MaxIndex).

[0184] Step 9: Filter the basic signal for digital AM broadcast signals as follows:

[0185] Step 91: Count the 3dB bandwidth and 10dB bandwidth of the spectrum of the basic signal. The bandwidth of the signal when the peak value of the basic signal drops by 3dB and 10dB is recorded as BW 3dB and BW 10dB ;

[0186] Among them, the 3dB bandwidth is the minimum bandwidth of the signal spectrum, so the bandwidth corresponding to the energy drop by half is selected; the purpose of the 10dB bandwidth is to select the maximum bandwidth of the signal spectrum.

[0187] Step 92: Calculate the rectangular coefficient RectCoef of the spectrum of the basic signal;

[0188]

[0189] Step 93: When RectCoef is greater than 0.85, it is a digital modulation signal;

[0190] Step 94: When the basic signal satisfies the digital modulation signal, it is determined whether the 10 dB bandwidth of the basic signal is approximately the DRM bandwidth of 9 kHz or 10 kHz, and if so, it is marked as a digital AM broadcast signal;

[0191] Step 95: The center frequency of the digital AM broadcast signal is BW 10dB The center position of the 10dB .

[0192] At present, there are also monitoring methods, the general process of the broadcast signal monitoring method is a method of combining broadband detection with multi-channel narrowband monitoring and identification. If the device is a low-cost, miniaturized device, and the device does not include multi-channel narrowband monitoring capabilities, then a method of combining broadband monitoring sorting with narrowband time-sharing identification is used. The steps of the broadcast signal monitoring method of low-cost equipment are as follows: 1) Use broadband monitoring data for signal sorting.

[0193] Start the device to perform broadband monitoring for a fixed time length, use the broadband spectrum data output by the device to perform statistics, and obtain the statistical spectrum and adaptive threshold; compare the statistical spectrum and the adaptive threshold, merge the sampling points that are continuously higher than the threshold into one signal, and take the center position of the continuous sampling points as the signal center frequency and the width of the continuous sampling points.

[0194] 2) Perform narrowband measurement and signal identification on each signal in the sorting list in turn.

[0195] Stop broadband monitoring, perform fixed-time measurement on each selected signal, start narrowband measurement and set the measurement center frequency and bandwidth, read the IQ data of the signal, and perform analog and digital broadcast signal identification.

[0196] Analog broadcasting is an AM modulated signal, and its identification method mostly uses statistical instantaneous feature recognition, including the signal's instantaneous amplitude sequence, frequency sequence, and the peak value and peak-to-average ratio of the instantaneous amplitude, the peak value and peak-to-average ratio of the instantaneous frequency, and then uses a decision tree for recognition.

[0197] Digital broadcasting is a DRM signal, which generally uses the autocorrelation method to detect the cyclic prefix of OFDM, and then compares the length of the cyclic prefix in different modes specified by the DRM protocol for identification.

[0198] The present invention also provides a broadcast signal broadband sorting system, which can be implemented by executing the process steps of the broadcast signal broadband sorting method, that is, technicians in this field can understand the broadcast signal broadband sorting method as a preferred implementation of the broadcast signal broadband sorting system.

[0199] A broadband sorting system for broadcast signals comprises: a module M1: collecting signal spectrum data within a preset filtering range for multiple times and setting an adaptive threshold; a module M2: denoising the signal according to the adaptive threshold and dividing the denoised signal into a signal containing a carrier and a signal not containing a carrier; a module M3: sorting analog broadcast signals for signals containing a carrier and outputting analog broadcast signals; a module M4: sorting digital amplitude modulation broadcast signals for signals not containing a carrier and outputting digital broadcast signals.

[0200] Preferably, the module M1 comprises: module M1.1: collecting signal spectrum data of a preset filtering range N times; module M1.2: calculating the mean spectrum value maxSpec of the i-th frequency point i , maximum spectrum value maxSpec i and the minimum spectrum value minSpec i ;

[0201]

[0202] maxSpec i =MAX(spec j,i )

[0203] minSpec i =MIN(spec j,i )

[0204] spec j,i Indicates the value of the i-th frequency point of the j-th spectrum acquisition; Module M1.3: obtains the basic threshold BasicTh by windowing the minimum spectrum value and performing median filtering; Module M1.4: sets the floating threshold value addTh. Specifically, the average change of the maximum spectrum value and the minimum spectrum value is used as the floating threshold:

[0205] Wherein, M represents the number of frequency points of a full-band spectrum frame; Module M1.5: Setting the adaptive threshold FinalTh to:

[0206] FinalTh=BasicTh+addTh;

[0207] The module M2 includes: Module M2.1: De-noising the collected signal; specifically, by using the mean spectrum value meanSpec i Compared with the adaptive threshold, the mean spectrum value meanSpec i The frequency points greater than the adaptive threshold are marked as signal frequencies, otherwise they are marked as noise frequencies and removed; Module M2.2: When two or more consecutive frequency points are marked as signal frequencies, the consecutive frequency points are recorded as a basic signal, and the nth basic signal is BS n , the starting frequency of the basic signal BS n1 and cutoff frequency BS n2 Module M2.3: Classify the basic signal into a signal containing a carrier and a signal without a carrier according to a preset rule; the module M2.3 includes: Module M2.3.1: In BS n1 to BS n2 The minimum value of the mean spectrum value is minV, and the basic signal is preprocessed to obtain the preprocessed basic signal set Representative from BS n1 to BS n2 The mean spectrum value set of BS n The maximum value in Proc is recorded as MaxS, the maximum value position is MaxIndex, and the second largest value is MaxS2; Module M2.3.3: When MaxS is greater than 2 times MaxS2 or greater than (MaxS2+10dB), it contains a carrier, and the corresponding signal is a signal containing a carrier; otherwise, it does not contain a carrier, and the corresponding signal is a signal without a carrier.

[0208] Preferably, the module M3 includes: module M3.1: judging the spectrum symmetry of the signal containing the carrier, if it is symmetrical, it is marked as an analog broadcast signal and enters module M3.2; if it is asymmetrical, other signals are directly output; module M3.2: outputting an analog broadcast signal, wherein the center frequency of the signal is the frequency corresponding to the MaxIndex position, and the bandwidth is 2 times the Max (MaxIndex-BS n1 , B.S. n1 -MaxIndex). The module M3.1 includes:

[0209] Module M3.1.1: Computing BSn Proc based on MaxIndex spectrum symmetry value P:

[0210]

[0211] x represents the spectrum position;

[0212] Where B = 2*min(MaxIndex-BS n1 , B.S. n2 -MaxIndex);

[0213] Module M3.1.2: When P ≥ 0.85, the spectrum is a symmetrical spectrum, otherwise it is an asymmetrical spectrum; the module M4 includes: Module M4.1: In a signal without a carrier, when the peak value of the spectrum drops to the preset spectrum minimum value, the bandwidth is BW min , when the peak value of the spectrum drops to the preset maximum value of the spectrum, the bandwidth is BWma max ;Module M4.2: Set the rectangular coefficient RectCoef of the basic signal spectrum;

[0214]

[0215] Module M4.3: If the rectangular coefficient RectCoef is greater than 0.85, the corresponding signal is a digital modulation signal; Module M4.4: Determine the BWma corresponding to the digital modulation signal max Whether it meets the preset bandwidth standard, if it does, it is marked as a digital AM broadcast signal and enters module M4.5; if it does not meet the standard, other signals are directly output; Module M4.5: Output digital broadcast signal, the center frequency of the signal is BW max The frequency corresponding to the middle position, the bandwidth is BW max .

[0216] Those skilled in the art know that, in addition to realizing the system and its various devices, modules, and units provided by the present invention in a purely computer-readable program code, it is entirely possible to realize the same functions in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered as a hardware component, and the devices, modules, and units included therein for realizing various functions can also be regarded as structures within the hardware component; the devices, modules, and units for realizing various functions can also be regarded as both software modules for realizing the method and structures within the hardware component.

[0217] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A method for broadband sorting of broadcast signals, characterized in that: include: Step S1: Collect signal spectrum data within a preset filtering range multiple times and set an adaptive threshold; Step S2: De-noising the signal according to the adaptive threshold, and dividing the de-noised signal into a signal containing a carrier and a signal without a carrier; Step S3: sorting the signal containing the carrier into analog broadcast signals, and outputting the analog broadcast signals; Step S4: sorting the digital AM broadcast signal from the signal without carrier wave, and outputting the digital broadcast signal.

2. The method for broadband sorting of broadcast signals according to claim 1, characterized in that: The step S1 comprises: Step S1.1: Collect signal spectrum data within a preset filtering range N times; Step S1.2: Calculate the mean spectrum value meanSpec of the i-th frequency point i , maximum spectrum value maxSpec i and the minimum spectrum value minSpec i ; maxSpec i =MAX(spec j，i ) mySpec i =MIN(spec j，i ) spec j，i Indicates the value of the i-th frequency point of the j-th spectrum acquisition; Step S1.3: Obtain a basic threshold BasicTh by performing windowed median filtering on the minimum spectrum value; Step S1.4: Set the floating threshold addTh. Specifically, the average change between the maximum spectrum value and the minimum spectrum value is used as the floating threshold: Wherein, M represents the number of frequency points in a full-band spectrum frame; Step S1.5: Set the adaptive threshold FinalTh to: FinalTh=BasicTh+addTh.

3. The method for broadband sorting of broadcast signals according to claim 1, characterized in that: The step S2 comprises: Step S2.1: De-noise the collected signal; specifically, by using the mean spectrum value meanSpec i Compared with the adaptive threshold, the mean spectrum value meanSpec i The frequency points that are greater than the adaptive threshold are marked as signal frequencies, otherwise they are marked as noise frequencies and removed; Step S2.2: When two or more consecutive frequency points are marked as signal frequency points, the consecutive frequency points are recorded as a basic signal, and the nth basic signal is BS. n , the starting frequency of the basic signal BS n1 and cutoff frequency BS n2 ; Step S2.3: According to a preset rule, the basic signal is classified into a signal containing a carrier and a signal without a carrier.

4. The method for broadband sorting of broadcast signals according to claim 3, characterized in that: The step S2.3 comprises: Step S2.3.1: In BS n1 to BS n2 The minimum value of the mean spectrum value is minV, and the basic signal is preprocessed to obtain the preprocessed basic signal set Representative from BS n1 to BS n2 The set of mean spectrum values ​​of ; Step S2.3.2: BS n The maximum value in Proc is recorded as MaxS, the maximum value position is MaxIndex, and the second largest value is MaxS2; Step S2.3.3: When MaxS is greater than 2 times of MaxS2 or greater than (MaxS2+lOdB), it contains a carrier and the corresponding signal is a signal containing a carrier; otherwise, it does not contain a carrier and the corresponding signal is a signal not containing a carrier.

5. The method for broadband sorting of broadcast signals according to claim 1, characterized in that: The step S3 comprises: Step S3.1: The signal containing the carrier is judged for spectrum symmetry. If it is symmetrical, it is marked as an analog broadcast signal and the process goes to step S3.

2. If it is asymmetrical, other signals are directly output. Step S3.2: Output an analog broadcast signal, wherein the center frequency of the signal is the frequency corresponding to the MaxIndex position, and the bandwidth is 2 times Max (MaxIndex-BS n1 , B.S. n1 -MaxIndex).

6. The method for broadband sorting of broadcast signals according to claim 5, characterized in that: The step S3.1 comprises: Step S3.1.1: Calculate BS n Proc based on MaxIndex spectrum symmetry value P: x represents the spectrum position; where B = 2 * min(MaxIndex - BS n1 , BS n2 - MaxIndex); Step S3.1.2: When P ≥ 0.85, the spectrum is a symmetrical spectrum, otherwise it is an asymmetrical spectrum.

7. The method for broadband sorting of broadcast signals according to claim 1, characterized in that: The step S4 comprises: Step S4.1: In a signal without a carrier, the bandwidth when the peak value of the spectrum drops to the preset spectrum minimum value is BW min , when the peak value of the spectrum drops to the preset maximum value of the spectrum, the bandwidth is BW max ; Step S4.2: Setting the rectangular coefficient RectCoef of the basic signal spectrum; Step S4.3: If the rectangular coefficient RectCoef is greater than 0.85, the corresponding signal is a digital modulation signal; Step S4.4: Determine the BW corresponding to the digital modulation signal max Whether the preset bandwidth standard is met, if so, it is marked as a digital AM broadcast signal and the process goes to step S4.5; if not, other signals are directly output; Step S4.5: Output digital broadcast signal, the center frequency of the signal is BW max The frequency corresponding to the middle position, the bandwidth is BW max .

8. A broadband sorting system for broadcast signals, characterized in that: include: Module M1: collects signal spectrum data within a preset filtering range multiple times and sets an adaptive threshold; Module M2: denoises the signal according to the adaptive threshold, and divides the denoised signal into a signal containing a carrier and a signal without a carrier; Module M3: sorting analog broadcast signals from signals containing carrier waves and outputting analog broadcast signals; Module M4: sorts digital AM broadcast signals from signals without carrier waves and outputs digital broadcast signals.

9. The broadcast signal broadband sorting system according to claim 8, characterized in that: The module M1 comprises: Module M1.1: collects signal spectrum data within a preset filtering range N times; Module M1.2: Calculate the mean spectrum value meanSpec of the i-th frequency point i , maximum spectrum value maxSpec i and the minimum spectrum value minSpec i ; maxSpec i =MAX(spec j，i ) mySpec i =MIN(spec j，i ) spec j，i Indicates the value of the i-th frequency point of the j-th spectrum acquisition; Module M1.3: Obtain the basic threshold BasicTh by performing windowed median filtering on the minimum spectrum value; Module M1.4: Set the floating threshold addTh. Specifically, the average change between the maximum spectrum value and the minimum spectrum value is used as the floating threshold: Wherein, M represents the number of frequency points in a full-band spectrum frame; Module M1.5: Set the adaptive threshold FinalTh to: FinalTh=BasicTh+addTh; The module M2 comprises: Module M2.1: De-noise the collected signal; specifically, through the mean spectrum value meanSpec i Compared with the adaptive threshold, the mean spectrum value meanSpec i The frequency points that are greater than the adaptive threshold are marked as signal frequencies, otherwise they are marked as noise frequencies and removed; Module M2.2: When two or more consecutive frequencies are marked as signal frequencies, the consecutive frequencies are recorded as a basic signal, and the nth basic signal is BS. n , the starting frequency of the basic signal BS n1 and cutoff frequency BS n2 ; Module M2.3: Classify the basic signals into signals with carriers and signals without carriers according to preset rules; The module M2.3 includes: Module M2.3.1: In BS n1 to BS n2 The minimum value of the mean spectrum value is minV, and the basic signal is preprocessed to obtain the preprocessed basic signal set H Representative from BS n1 to BS n2 The set of mean spectrum values ​​of ; Module M2.3.2: BS n The maximum value in Proc is recorded as MaxS, the maximum value position is MaxIndex, and the second largest value is MaxS2; Module M2.3.3: When MaxS is greater than 2 times of MaxS2 or greater than (MaxS2+l0dB), it contains a carrier and the corresponding signal is a signal containing a carrier; otherwise, it does not contain a carrier and the corresponding signal is a signal without a carrier.

10. The broadcast signal broadband sorting system according to claim 8, characterized in that: The module M3 comprises: Module M3.1: The signal containing the carrier is judged for spectrum symmetry. If it is symmetrical, it is marked as an analog broadcast signal and enters module M3.2; if it is asymmetrical, other signals are directly output; Module M3.2: Output analog broadcast signal, where the center frequency of the signal is the frequency corresponding to the MaxIndex position, and the bandwidth is 2 times Max (MaxIndex-BS n1 , B.S. n1 -MaxIndex); The module M3.1 includes: Module M3.1.1: Computing BS n Proc based on MaxIndex spectrum symmetry value P: x represents the spectrum position; where B = 2 * min(MaxIndex - BS n1 , BS n2 - MaxIndex); Module M3.1.2: When P ≥ 0.85, the spectrum is a symmetrical spectrum, otherwise it is an asymmetrical spectrum; The module M4 comprises: Module M4.1: In a signal without a carrier, the bandwidth when the peak value of the spectrum drops to the preset spectrum minimum value is BW min , when the peak value of the spectrum drops to the preset maximum value of the spectrum, the bandwidth is BW max ; Module M4.2: Set the rectangular coefficient RectCoef of the basic signal spectrum; Module M4.3: If the rectangular coefficient RectCoef is greater than 0.85, the corresponding signal is a digital modulation signal; Module M4.4: Determine the BW corresponding to the digital modulation signal max Whether the preset bandwidth standard is met, if so, it is marked as a digital AM broadcast signal and enters module M4.5; if not, other signals are directly output; Module M4.5: Output digital broadcast signal, the center frequency of the signal is BW max The frequency corresponding to the middle position, the bandwidth is BW max .

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