Preprocessing system for cancelling interference within adjacent ranges of HDR and CDR analog signals

Abstract

The invention discloses a pre-processing system for eliminating interference in adjacent ranges of analog signals of HDR and CDR. The present embodiment provides a pre-processing system for cancelling interference within adjacent ranges of analog signals of HDR and CDR, which, in the process of receiving hybrid digital radio (HDR, Hybrid Digital Radio) and Content Digital Radio (CDR, Conditional Digital Radio), restores the Symmetric attribute, and in addition, uses the FM phase (Phase) characteristic of the signal to determine whether the signal is noisy, thereby eliminating interference within adjacent ranges of the analog signals of HDR and CDR. Therefore, interference in an adjacent range of analog signals can be eliminated through a single path under the condition that beam forming (more than two paths) is not used.

Description

Technical Field

[0001] One embodiment of the present invention relates to a preprocessing system for eliminating interference in the adjacent range of HDR and CDR analog signals. Background Technology

[0002] The following description provides background information related to this embodiment only and does not constitute prior art.

[0003] CDR stands for Conventional Digital Radio or China Digital Radio.

[0004] It is divided into the European standard Digital Audio Broadcasting (DAB), the Third World standard Digital Radio Mondiale (DRM), the American standard HDR, and the Chinese standard CDR.

[0005] Hybrid Digital Radio (HDR) is a radio broadcasting technology that combines analog and digital broadcasting. HDR radio is a digital radio technology manufactured under license from iBiquity Digital Corporation in the United States.

[0006] like Figure 1 As shown, FM radio in the United States transmits radio signals in 200kHz units. HDR uses a method that mixes existing FM(N) with digital (N) signals for transmission.

[0007] In other words, HDR transmits the same digital radio signal on both sidebands of an analog FM signal. The lower digital sideband (LDS) and upper digital sideband (UDS) of HDR are symmetrical to each other and are designed to be listenable even if only one of the LDS or UDS is fully recovered.

[0008] In the United States, frequencies are managed to ensure that neither side of the HDR digital signal is affected.

[0009] like Figure 2 As shown in (a), interference typically occurs only within the adjacent range of one sideband. When interference occurs only within the adjacent range of one sideband, the signal is recovered by using the signal from the other sideband, which is unaffected by the interference.

[0010] However, when the reception signal of the adjacent channel is significantly greater than the reception signal of the original channel, there is a problem that the signal cannot be recovered since it exceeds the signal range that can be digitally expressed.

[0011] As Figure 2 As shown in (b) of the drawing, when crossing the border or the region, both the lower digital sideband (LDS) and the upper digital sideband (UDS) are deteriorated due to the adjacent channel. When both sidebands are deteriorated, there is not only a problem of deterioration of the moving performance, but also a problem of difficulty in recovery due to the low SNR of the digital level in the adjacent channel. SUMMARY

[0012] PROBLEMS TO BE SOLVED BY THE INVENTION

[0013] In the present embodiment, the object is to provide a pre-processing system for eliminating interference in the adjacent range of the HDR and CDR analog signal, which, in the process of receiving a hybrid digital radio (HDR) and a conventional digital radio (CDR), restores the symmetric property, and additionally, uses the FM phase property of the signal to determine whether the signal has noise, so that the interference in the adjacent range of the analog signal can be eliminated by a single path without using beamforming (more than two paths).

[0014] MEANS FOR SOLVING THE PROBLEMS

[0015] According to an aspect of the present embodiment, there is provided a pre-processing system including: a CDR / HDR RF receiving section that receives a radio frequency (RF) signal of a conventional digital radio (CDR) or a hybrid digital radio (HDR); a data folding section that, when an upper digital sideband (UDS) or a lower digital sideband (LDS) in the adjacent range of an analog signal N of the CDR or the HDR is interfered, or both the UDS and the LDS on both sides are interfered, identifies as noise and divides into a symmetric region based on the center by a data folding method and using the symmetric property of the analog signal (N-1, N+1) in which the interference occurs; and a CDR / HDR restoring section that restores the signal by eliminating the interference based on the symmetric region.

[0016] Effects of the Invention

[0017] As described above, according to the present embodiment, there is an effect that, in receiving a Hybrid Digital Radio (HDR) and a Conventional Digital Radio (CDR), by symmetric property restoration, and further, using an FM phase property of a signal to determine whether the signal has noise, it is possible to eliminate interference in an analog signal adjacent range by a single path without using beam forming (two or more paths). BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 And Figure 2 is a graph for explaining a feature of an HDR of the related art.

[0019] Figure 3 is a graph showing a method of the present embodiment for restoring a USD in an analog signal adjacent range using a data folding method.

[0020] Figure 4 is a graph showing an analog result of a method of the present embodiment for restoring a USD in an analog signal adjacent range using a data folding method.

[0021] Figure 5 is a graph showing a method of the present embodiment for restoring a LDS in an analog signal adjacent range using a data folding method.

[0022] Figure 6 is a graph showing a method of the present embodiment for restoring a LDS and a USD in an analog signal adjacent range using a data folding method.

[0023] Figure 7 is a graph showing a starting point of a data folding method of the present embodiment.

[0024] Figure 8 is a graph showing a restoration process of an HDR and a CDR of the present embodiment.

[0025] EXPLANATION OF REFERENCE NUMERALS

[0026] 800: pre-processing system

[0027] 810: first CDR / HDR RF receiving section

[0028] 820: data folding section

[0029] 830: second CDR / HDR RF receiving section

[0030] 840: filter section

[0031] 850: Adjacent filter controller

[0032] 860: CDR / HDR recovery section DETAILED DESCRIPTION

[0033] Hereinafter, the present embodiment will be described in detail with reference to the accompanying drawings.

[0034] Figure 3 is a diagram showing a method of recovering a USD in an adjacent range of an analog signal using a data folding method according to the present embodiment.

[0035] When a UDS (Upper Digital Sideband) in an adjacent range of an analog signal N of a received CDR or HDR occurs interference, the preprocessing system 800 can recognize it as noise and recover a signal by eliminating the interference occurring in the USD using a data folding method.

[0036] For a CDR having the same spectral structure as the HDR, when interference in an adjacent range of an analog signal N occurs, the preprocessing system 800 can recognize it as noise and recover a signal by eliminating the interference occurring in the adjacent range using a data folding method. Here, the preprocessing system 800 can apply a different spectrum spacing (Spectrum Spacing) to the CDR than the HDR, but can apply the same concept as the HDR to eliminate interference in an adjacent range of an analog signal.

[0037] The preprocessing system 800 receives a radio frequency (RF, Radio Frequency) signal of a CDR (Conventional Digital Radio) or a HDR (Hybrid Digital Radio).

[0038] When a UDS in an adjacent range of an analog signal N of a CDR or HDR occurs interference, the preprocessing system 800 can recognize it as noise and select an analog signal N+1 in which the UDS in the adjacent range of the analog signal N has occurred interference.

[0039] The preprocessing system 800 divides the analog signal N+1 in which the UDS has occurred interference into 2 symmetric regions (an interference-occurring region (region ② of FIG. 10) and an interference-non-occurring region (region ① of FIG. 10)) using a symmetric property of the analog signal N+1 in which the UDS has occurred interference as a center. Figure 3 Figure 3

[0040] The preprocessing system 800 performs adjustment processing to adjust the interference-non-occurring region (region ① of FIG. 10) of the 2 symmetric regions. Figure 3 ​​the frequency domain of the interference-occurred region (b) of the adjacent range of the analog signal N+1. Figure 3

[0041] The pre-processing system 800 recovers the UDS by subtracting the frequency domain of the interference-occurred region from the frequency domain of the interference-non-occurred region.

[0042] Figure 4 is a graph showing an analog result of a method of recovering the UDS in the adjacent range of the analog signal using a data folding method according to the present embodiment.

[0043] The pre-processing system 800 receives an RF signal of a CDR (Conventional Digital Radio) or an HDR (Hybrid Digital Radio). When the LDS (Lower Digital Sideband) in the adjacent range of the analog signal N of the CDR or the HDR is interfered, the analog signal N+1 in which the LDS in the adjacent range of the analog signal N is interfered is as shown in (a) of FIG. 10. Figure 4

[0044] The pre-processing system 800 divides the center as a basis into two symmetric regions by using the symmetric property of the analog signal N+1 in which the LDS is interfered. The UDS is recovered by subtracting the frequency domain of the interference-non-occurred region from the frequency domain of the interference-occurred region, and the signal of the analog signal N+1 in which the interference is occurred is recovered by performing an adjustment process of symmetrically copying the frequency domain of the interference-non-occurred region in the symmetric region to the interference-occurred region as shown in (b) of FIG. 10. Figure 4

[0045] Figure 5 is a graph showing a method of recovering the LDS in the adjacent range of the analog signal using a data folding method according to the present embodiment.

[0046] When the LDS (Lower Digital Sideband) in the adjacent range of the analog signal N of the received CDR or HDR is interfered, the pre-processing system 800 can recognize it as noise and recover the signal by eliminating the interference of the LDS using a data folding method.

[0047] ​​​In case of CDR having the same spectrum structure as the HDR, when interference occurs in the adjacent range of the analog signal N, the pre-processing system 800 can recognize it as noise and restore the signal by eliminating the interference occurring in the adjacent range using a data folding method. Here, the pre-processing system 800 can apply a different spectrum spacing (Spectrum Spacing) to the CDR than the HDR, but can apply the same concept as the HDR to eliminate the interference in the adjacent range of the analog signal.

[0048] The pre-processing system 800 receives an RF signal of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio).

[0049] When LDS in the adjacent range of the analog signal N of the CDR or the HDR is interfered, the pre-processing system 800 can recognize it as noise and select the analog signal N-1 in which the LDS in the adjacent range of the analog signal N is interfered.

[0050] The pre-processing system 800 divides the analog signal N-1 in which the LDS is interfered into two symmetric regions (a region in which interference occurs (region ②) and a region in which interference does not occur (region ①)) using a symmetric property of the analog signal N-1 in which the LDS is interfered, with the center as a reference. Figure 5 Figure 5 The pre-processing system 800 divides the analog signal N-1 in which the LDS is interfered into two symmetric regions (a region in which interference occurs (region ②) and a region in which interference does not occur (region ①)) using a symmetric property of the analog signal N-1 in which the LDS is interfered, with the center as a reference.

[0051] The pre-processing system 800 performs adjustment processing to symmetrically copy the frequency domain of the region in which interference does not occur (region ①) to the region in which interference occurs (region ②) among the two symmetric regions, thereby restoring the analog signal N-1 of the adjacent channel in which interference occurs. Figure 5 Figure 5 The pre-processing system 800 restores the LDS by subtracting the frequency domain of the copied region in which interference does not occur from the frequency domain of the region in which interference occurs.

[0052] The pre-processing system 800 restores the LDS by subtracting the frequency domain of the copied region in which interference does not occur from the frequency domain of the region in which interference occurs.

[0053] Figure 6 FIG. 1 is a diagram illustrating a method of restoring an analog signal adjacent range LDS and USD using a data folding method according to the present embodiment.

[0054] When the LDS (Lower Digital Sideband) in the adjacent range of the received analog signal N of the CDR or the HDR is interfered, the pre-processing system 800 can recognize it as noise and restore the signal by eliminating the interference occurring in the LDS using a data folding method.

[0055] ​​For a CDR with the same spectral structure as HDR, when interference occurs in the adjacent range of the analog signal N, the preprocessing system 800 can identify it as noise and recover the signal by eliminating the interference occurring in the adjacent range using a data folding method. Here, the preprocessing system 800 can apply a different spectral spacing than HDR to the CDR, but can apply the same concept as HDR to eliminate interference in the adjacent range of the analog signal.

[0056] The preprocessing system 800 receives RF signals from CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio).

[0057] When interference occurs in the LDS within the adjacent range of the analog signal N of CDR or HDR, the preprocessing system 800 can identify it as noise and select the analog signal N-1 that has interfered with the LDS within the adjacent range of the analog signal N.

[0058] The preprocessing system 800 utilizes the symmetric property of the analog signal N-1 that interfered with the LDS, dividing it into two symmetrical regions (interference region and interference region) with the center as the reference. Figure 6 Area ②) and areas where interference did not occur ( Figure 5 Area ①).

[0059] The preprocessing system 800 performs adjustment processing to separate the interference-free areas in the two symmetrical regions. Figure 6 A symmetric copy of the frequency domain of region ① is applied to the interference-generating region. Figure 6 In region ②), the analog signal N-1 of the adjacent channel that was interfered with is recovered.

[0060] The preprocessing system 800 recovers the LDS by subtracting the frequency domain of the copied non-interference region from the frequency domain of the interference-occurring region.

[0061] When interference occurs in the UDS within the adjacent range of the analog signal N of CDR or HDR, the preprocessing system 800 can identify it as noise and select the analog signal N+1 that has interfered with the UDS within the adjacent range of the analog signal N.

[0062] The preprocessing system 800 utilizes the symmetric property of the analog signal N+1 that interfered with the UDS, dividing it into two symmetrical regions (interference region and interference region) with the center as the reference. Figure 6 Area ④) and areas where interference did not occur (Figure 6 of region ③) of region ③).

[0063] The preprocessing system 800 performs adjustment processing to symmetrically copy (Symmetric Copy) the frequency domain of the region ③ where no interference occurs in the two symmetric regions to the region ④ where interference occurs, thereby recovering the analog signal N+1 of the adjacent channel where interference occurs. Figure 6 Figure 6 The preprocessing system 800 recovers the UDS by subtracting the copied frequency domain of the region where no interference occurs from the frequency domain of the region where interference occurs.

[0064] The preprocessing system 800 recovers the UDS by subtracting the copied frequency domain of the region where no interference occurs from the frequency domain of the region where interference occurs.

[0065] Figure 7 FIG. 1 is a diagram illustrating a starting point of a data folding method of the present embodiment.

[0066] The preprocessing system 800 can use various noise extraction methods. The preprocessing system 800 can additionally determine whether noise exists in the signal using the FM phase characteristics of the signal recovered by the symmetric property.

[0067] The preprocessing system 800 is not limited to feedback active noise cancellation (FB-ANC), and can be configured only with feed forward active noise cancellation (FF-ANC), and as an auxiliary technology that can use the FB-ANC, can cancel noise based on artificial intelligence.

[0068] The preprocessing system 800 can estimate noise using artificial intelligence.

[0069] The preprocessing system 800 extracts feature points from the nth audio signal and subsequent audio signals (N+1, n+2, n+3) stored in the memory after the nth audio signal, respectively.

[0070] The preprocessing system 800 generates coordinate information about the position where the extracted feature points are formed in the frequency domain. The preprocessing system 800 inputs the generated coordinate information of each feature point as an input value to a pre-learned artificial neural network. Here, the artificial neural network includes a deep neural network consisting of an input layer, a hidden layer, and an output layer.

[0071] The preprocessing system 800 estimates a noise signal included in an audio signal input at the next signal processing based on the output value of the artificial neural network.

[0072] ​The preprocessing system 800 predicts an occurrence position of next coordinate information based on a movement pattern of the coordinate information of the feature point input to the artificial neural network, through the artificial neural network. The preprocessing system 800 extracts a noise signal having a frequency characteristic corresponding to the predicted occurrence position from the audio signal.

[0073] The preprocessing system 800 calculates a similarity between the noise signal predicted through the artificial neural network and the noise signal actually detected through the noise detection section. The preprocessing system 800 adjusts the weight between the nodes constituting the artificial neural network based on the calculated similarity.

[0074] For example, the preprocessing system 800 calculates a similarity between a signal pattern of the noise signal predicted through the artificial neural network and a signal pattern of the noise signal actually detected through the noise detection section. When the calculated similarity is less than a preset standard similarity, the preprocessing system 800 adjusts the weight between the nodes constituting the artificial neural network until it reaches above the standard similarity.

[0075] The preprocessing system 800 can predict the noise included in the audio signal using the artificial neural network, and further remove the noise not detected through the noise detection section, so that the noise removal performance can be improved.

[0076] When noise occurs in the LDS (Lower Digital Sideband) in the adjacent range of the received CDR or HDR analog signal N, the preprocessing system 800 can judge the noise using a data folding method.

[0077] Hereinafter, based on Figure 7 (a), a method of judging noise occurring in the adjacent range of the CDR or HDR analog signal N will be described.

[0078] As shown in (a) of Figure 7 , the preprocessing system 800 receives an RF signal of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio).

[0079] When noise occurs in the LDS in the adjacent range of the CDR or HDR analog signal N, the preprocessing system 800 selects a signal N-1 in which noise has occurred in the adjacent range of the analog signal N.

[0080] The preprocessing system 800 divides the signal N-1 in which noise has occurred into 2 symmetric regions (a noise occurrence region (region ② of Figure 7 ) and a noise non-occurrence region (region ① of Figure 7 )) using a symmetric property of the signal N-1 in which noise has occurred, with the center as a reference.

[0081] The preprocessing system 800 performs adjustment processing to symmetrically copy the frequency domain of the noise-occurred region (region ③ of (b)) to the noise-non-occurred region (region ④ of (b)) of the two symmetric regions, thereby generating a symmetric noise-occurred region signal. Figure 7 Figure 7 The preprocessing system 800 performs adjustment processing to symmetrically copy the frequency domain of the noise-occurred region (region ③ of (b)) to the noise-non-occurred region (region ④ of (b)) of the two symmetric regions, thereby generating a symmetric noise-occurred region signal.

[0082] The preprocessing system 800 performs adjustment processing to symmetrically copy the frequency domain of the noise-occurred region (region ③ of (b)) to the noise-non-occurred region (region ④ of (b)) of the two symmetric regions, thereby generating a symmetric noise-occurred region signal.

[0083] Hereinafter, a method of ignoring a negative value in the frequency domain with respect to noise occurring in the adjacent range of the analog signal N of the CDR or the HDR based on (b) of FIG. 8 will be described. Figure 7 As shown in (b) of FIG. 8, when noise occurs in the LDS in the adjacent range of the analog signal N of the CDR or the HDR, the preprocessing system 800 selects the signal N-1 in which noise occurs in the adjacent range of the analog signal N.

[0084] Figure 7 As shown in (b) of FIG. 8, when noise occurs in the LDS in the adjacent range of the analog signal N of the CDR or the HDR, the preprocessing system 800 selects the signal N-1 in which noise occurs in the adjacent range of the analog signal N.

[0085] The preprocessing system 800 performs adjustment processing to symmetrically copy the frequency domain of the noise-occurred region (region ③ of (b)) to the noise-non-occurred region (region ④ of (b)) of the two symmetric regions, thereby generating a symmetric noise-occurred region signal. Figure 7 Figure 7 The preprocessing system 800 performs adjustment processing to symmetrically copy the frequency domain of the noise-occurred region (region ③ of (b)) to the noise-non-occurred region (region ④ of (b)) of the two symmetric regions, thereby generating a symmetric noise-occurred region signal.

[0086] The preprocessing system 800 performs adjustment processing to symmetrically copy the frequency domain of the noise-occurred region (region ③ of (b)) to the noise-non-occurred region (region ④ of (b)) of the two symmetric regions, thereby generating a symmetric noise-occurred region signal. Figure 7 Figure 8 The preprocessing system 800 performs adjustment processing to symmetrically copy the frequency domain of the noise-occurred region (region ③ of (b)) to the noise-non-occurred region (region ④ of (b)) of the two symmetric regions, thereby generating a symmetric noise-occurred region signal.

[0087] The preprocessing system 800 performs adjustment processing to symmetrically copy the frequency domain of the noise-occurred region (region ③ of (b)) to the noise-non-occurred region (region ④ of (b)) of the two symmetric regions, thereby generating a symmetric noise-occurred region signal.

[0088] ​​​​The pre-processing system 800 ignores (Ignore Negative value in Frequency domain) the negative value of the symmetrical noise in the frequency domain.

[0089] The pre-processing system 800 subtracts the signal having the negative value of the symmetrical noise in the frequency domain from the signal in which only the noise is separated in the frequency domain, thereby separating only the noise in the frequency domain.

[0090] ​ FIG. 1 is a diagram illustrating a recovery process of an HDR and a CDR according to an embodiment of the present disclosure.

[0091] The pre-processing system 800 performs MRC preprocessing of a beam forming method for removing interference in the adjacent range of the CDR / HDR analog signal.

[0092] The pre-processing system 800 applies a filter to the sideband of the channel selected in the reception process of the digital radio and forms RF beam forming using the gain (Gain) difference of the automatic gain control (AGC), which is preferably implemented in the radio reception device of the vehicle, but is not limited thereto.

[0093] The pre-processing system 800 can remove the interference in the adjacent range of the analog signal through a single path without using beam forming (more than two paths). The pre-processing system 800 reflects and corrects the weight of the uncertainty of the analog co-channel residual offset that tracks the RF signal from the CDR or the HDR.

[0094] The pre-processing system 800 has a hybrid structure of the beam forming method and the data folding. The pre-processing system 800 has a structure that simultaneously obtains the gain by processing the analog co-channel recovery gain and the beam forming through the data folding method (single path).

[0095] The pre-processing system 800 further includes a noise removal module (not shown) that tracks and removes the noise included in the RF signal of the CDR or the HDR received from the first CDR / HDR RF reception part 810 or the second CDR / HDR RF reception part 830.

[0096] The noise cancellation module includes a noise detection section (not shown) that performs a fast Fourier transform of the CDR or HDR RF signal into a frequency domain, detects noise from the fast Fourier transformed signal, and a feed-forward active noise control (ANC) section (not shown) that cancels the noise detected by the noise detection section, performs an inverse fast Fourier transform of the CDR or HDR RF signal from which the noise is cancelled into a time domain, and stores the inverse fast Fourier transformed signal in a memory.

[0097] The pre-processing system 800 according to the present embodiment includes a first CDR / HDR RF receiving section 810, a data folding section 820, a second CDR / HDR RF receiving section 830, a filter section 840, an adjacent filter controller 850, and a CDR / HDR recovery section 860. The constituent elements included in the pre-processing system 800 are not limited to this.

[0098] The first CDR / HDR RF receiving section 810 receives a CDR or HDR RF signal.

[0099] When the UDS (Upper Digital Sideband) or the LDS (Lower Digital Sideband) in the adjacent range of the received CDR or HDR analog signal N is interfered or both the UDS and the LDS on both sides are interfered, the data folding section 820 can recognize this as noise and recover the signal by canceling the interference occurring in the UDS using a data folding method.

[0100] The data folding section 820 divides the analog signal N+1 in which the UDS of the CDR or HDR analog signal N is interfered into an interference occurring region and an interference non-occurring region using the symmetry property of the analog signal N+1.

[0101] The data folding section 820 divides the analog signal N-1 in which the LDS of the CDR or HDR analog signal N is interfered into an interference occurring region and an interference non-occurring region using the symmetry property of the analog signal N-1.

[0102] The data folding section 820 divides the analog signals N-1 and N+1 in which the LDS and the UDS of the CDR or HDR analog signal N are interfered into an interference occurring region and an interference non-occurring region using the symmetry property of the analog signals N-1 and N+1.

[0103] When UDS or LDS in the adjacent range of analog signal N of CDR or HDR occurs interference or both UDS and LDS in the adjacent range of analog signal N occur interference, the data folding part 820 can recognize it as noise and divide into two symmetric regions (interference occurrence region and interference non-occurrence region) using the symmetric property of analog signal N-1 and N+1 in which interference occurs, with the center as a reference, by the data folding method.

[0104] Hereinafter, a method of recovering a signal by eliminating interference occurring in UDS by the data folding part 820 and the CDR / HDR recovery part 860 will be described.

[0105] When UDS (Upper Digital Sideband) in the adjacent range of received analog signal N of CDR or HDR occurs interference, the data folding part 820 can recognize it as noise and recover a signal by eliminating interference occurring in UDS using the data folding method.

[0106] The data folding part 820 receives an RF signal of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio).

[0107] When UDS in the adjacent range of analog signal N of CDR or HDR occurs interference, the data folding part 820 recognizes it as noise and selects analog signal N+1 in which UDS in the adjacent range of analog signal N occurs interference.

[0108] The data folding part 820 divides into two symmetric regions (interference occurrence region and interference non-occurrence region) using the symmetric property of analog signal N+1 in which UDS occurs interference, with the center as a reference.

[0109] The CDR / HDR recovery part 860 performs adjustment processing to symmetric copy the frequency domain of the interference non-occurrence region in the two symmetric regions to the interference occurrence region, thereby recovering analog signal N+1 of the adjacent channel in which interference occurs.

[0110] The CDR / HDR recovery part 860 recovers UDS by subtracting the copied frequency domain of the interference non-occurrence region from the frequency domain of the interference occurrence region.

[0111] Hereinafter, a method of recovering a signal by eliminating interference occurring in LDS by the data folding part 820 and the CDR / HDR recovery part 860 will be described.

[0112] When interference occurs in the LDS (Lower Digital Sideband) in the adjacent range of the analog signal N of the received CDR or HDR, the data folding unit 820 can recognize it as noise and restore the signal by eliminating the interference occurring in the LDS using a data folding method.

[0113] The data folding unit 820 receives an RF signal of a CDR (Conventional Digital Radio) or an HDR (Hybrid Digital Radio).

[0114] When interference occurs in the LDS in the adjacent range of the analog signal N of the CDR or the HDR, the data folding unit 820 can recognize it as noise and select an analog signal N-1 in which interference occurs in the LDS in the adjacent range of the analog signal N.

[0115] The data folding unit 820 divides the analog signal N-1 in which interference occurs in the LDS into 2 symmetric regions (an interference-occurring region and an interference-non-occurring region) using a symmetric property of the analog signal N-1 in which interference occurs in the LDS, with the center as a reference.

[0116] The CDR / HDR restoring unit 860 performs adjustment processing to symmetrically copy the frequency domain of the interference-non-occurring region to the interference-occurring region among the 2 symmetric regions, thereby restoring the analog signal N-1 of the adjacent channel in which interference occurs.

[0117] The CDR / HDR restoring unit 860 restores the LDS by subtracting the copied frequency domain of the interference-non-occurring region from the frequency domain of the interference-occurring region.

[0118] Hereinafter, a method of eliminating interference occurring in the LDS and the USD by the data folding unit 820 and the CDR / HDR restoring unit 860 and restoring the signal will be described.

[0119] When interference occurs in the LDS (Lower Digital Sideband) in the adjacent range of the analog signal N of the received CDR or HDR, the data folding unit 820 can recognize it as noise and restore the signal by eliminating the interference occurring in the LDS using a data folding method.

[0120] The data folding unit 820 receives an RF signal of a CDR (Conventional Digital Radio) or an HDR (Hybrid Digital Radio).

[0121] When the LDS in the adjacent range of the analog signal N of the CDR or the HDR is interfered, the data folding section 820 can recognize it as noise and select the analog signal N-1 in which the LDS in the adjacent range of the analog signal N is interfered.

[0122] The data folding section 820 divides into 2 symmetric regions (interference occurrence region and interference non-occurrence region) using the symmetric property of the analog signal N-1 in which the LDS is interfered, with the center as a reference.

[0123] The CDR / HDR recovery section 860 performs adjustment processing to symmetric copy the frequency domain of the interference non-occurrence region in the 2 symmetric regions to the interference occurrence region, thereby recovering the analog signal N-1 of the adjacent channel in which the interference occurs.

[0124] The CDR / HDR recovery section 860 recovers the LDS by subtracting the frequency domain of the copied interference non-occurrence region from the frequency domain of the interference occurrence region.

[0125] When the UDS in the adjacent range of the analog signal N of the CDR or the HDR is interfered, the data folding section 820 recognizes it as noise and selects the analog signal N+1 in which the UDS in the adjacent range of the analog signal N is interfered.

[0126] The data folding section 820 divides into 2 symmetric regions (interference occurrence region and interference non-occurrence region) using the symmetric property of the analog signal N+1 in which the UDS is interfered, with the center as a reference.

[0127] The CDR / HDR recovery section 860 performs adjustment processing to symmetric copy the frequency domain of the interference non-occurrence region in the 2 symmetric regions to the interference occurrence region, thereby recovering the analog signal N+1 of the adjacent channel in which the interference occurs.

[0128] The CDR / HDR recovery section 860 recovers the UDS by subtracting the frequency domain of the copied interference non-occurrence region from the frequency domain of the interference occurrence region.

[0129] The second CDR / HDR RF receiving section 830 receives an RF signal of a CDR (Conventional Digital Radio) or an HDR (Hybrid Digital Radio).

[0130] The filter section 840 allows only a lower sideband signal below a center frequency of an RF signal of a CDR or an HDR or only an upper sideband signal above the center frequency to pass in a selected channel.

[0131] The filter section 840 includes a 1-1 filter, a 1-2 filter, a 2-1 filter, and a 2-2 filter.

[0132] The filter section 840 includes a plurality of filters that allow only a specific band frequency to pass, and can selectively extract a signal under the control of the adjacent filter controller 850.

[0133] The filter section 840 uses any one of the 1-1 filter, the 1-2 filter, the 2-1 filter, and the 2-2 filter to allow only a lower sideband signal below a center frequency of a radio signal or only an upper sideband signal above the center frequency to pass in a selected channel.

[0134] When the filter section 840 has a 2-1 filter characteristic, total energy corresponding to FM and N+1 adjacent signals of an original signal can be transferred to an LDS and amplify the signal.

[0135] When the filter section 840 has a 2-2 filter characteristic, total energy corresponding to FM and N-1 adjacent signals of an original signal can be transferred to a UDS and amplify the signal.

[0136] When the filter section 840 has a 1-1 filter characteristic, partial energy corresponding to FM and N+1 / N-1 adjacent signals of an original signal can be separately transferred to an LDS and a UDS.

[0137] When the filter section 840 has a 1-2 filter characteristic, partial energy corresponding to FM and N+1 / N-1 adjacent signals of an original signal can be transferred to the original signal.

[0138] The adjacent filter controller 850 selects any one of the 1-1 filter, the 1-2 filter, the 2-1 filter, and the 2-2 filter by controlling the filter section 840.

[0139] The CDR / HDR recovery section 860 recovers a signal by removing interference based on a symmetric region.

[0140] The CDR / HDR recovery section 860 performs beamforming on a selected channel based on a difference in a gain value of a signal that has passed through the filter section 840 and an original signal that has not passed through the filter section 840. The CDR / HDR recovery section 860 uses a gain (Gain) difference of automatic gain control (AGC) to recover beamforming and a signal.

[0141] The CDR / HDR recovery part 860 processes the signal by using a Maximum Ratio Combining (MRC) algorithm. The MRC algorithm refers to a technique of giving weight to a good part of a channel when the maximum amount is created by adjusting a phase.

[0142] The CDR / HDR recovery part 860 can recover the LDS from the LDS and the LDS adjacent signal. The CDR / HDR recovery part 860 can recover the UDS from the UDS and the UDS adjacent signal. The CDR / HDR recovery part 860 can reflect Channel status information (CSI) channel weight with as low a probability as much as a frequency offset occurs at the FM phase tracking time (as much as overlap occurs).

[0143] The CDR / HDR recovery part 860 recovers the analog signal N+1 in which interference has occurred by performing adjustment processing of symmetrically copying the frequency domain of the interference non-occurrence area to the interference occurrence area, and recovers the UDS by subtracting the copied frequency domain of the interference non-occurrence area from the frequency domain of the interference occurrence area.

[0144] The CDR / HDR recovery part 860 recovers the analog signal N-1 in which interference has occurred by performing adjustment processing of symmetrically copying the frequency domain of the interference non-occurrence area to the interference occurrence area, and recovers the LDS by subtracting the copied frequency domain of the interference non-occurrence area from the frequency domain of the interference occurrence area.

[0145] The CDR / HDR recovery part 860 recovers the analog signals N-1 and N+1 in which interference has occurred by performing adjustment processing of symmetrically copying the frequency domain of the interference non-occurrence area to the interference occurrence area, and recovers the LDS and the USD by subtracting the copied frequency domain of the interference non-occurrence area from the frequency domain of the interference occurrence area.

[0146] The CDR / HDR recovery part 860 performs beamforming on the selected channel based on a difference in a gain value of a signal that has passed through the filter part 840 and an original signal that has not passed through the filter part 840.

[0147] The above description is merely illustrative of the technical idea of the present embodiment, and various modifications and changes can be made by those skilled in the art to which the present embodiment belongs without departing from the essential characteristics of the present embodiment. Therefore, the present embodiment is not intended to limit the technical idea of the present embodiment, but to illustrate it, and the scope of the technical idea of the present embodiment is not limited by these embodiments. The scope of protection of the present embodiment should be interpreted according to the claims, and all technical ideas within the equivalent scope should be interpreted as included in the right scope of the present embodiment.

Claims

1. A preprocessing system, characterized in that, include: CDR / HDR RF receiver unit, which receives RF signals of CDR or HDR; The data folding section identifies noise when UDS or LDS within the adjacent range of the analog signal (N) of the CDR or HDR is interfered with, or when both the UDS and LDS on both sides are interfered with. It then divides the data into symmetrical regions with the center as a reference by using the data folding method and the symmetry properties of the interfered analog signals (N-1, N+1). The CDR / HDR restoration unit restores the signal by eliminating the interference based on the symmetrical region.

2. The preprocessing system according to claim 1, characterized in that, The data folding section utilizes the symmetry property of the analog signal (N+1) that interferes with the UDS of the analog signal (N) of the CDR or the HDR to divide the region into an interference-occurring region and an interference-free region with the center as a reference. The CDR / HDR recovery unit recovers the analog signal (N+1) that has been interfered with by performing an adjustment process that symmetrically copies the frequency domain of the interference-free region to the interference-occurring region, and recovers the UDS by subtracting the frequency domain of the copied interference-free region from the frequency domain of the interference-occurring region.

3. The preprocessing system according to claim 1, characterized in that, The data folding section utilizes the symmetry property of the analog signal (N-1) that interferes with the LDS of the analog signal (N) of the CDR or the HDR to divide the region into an interference-occurring region and an interference-free region with the center as a reference. The CDR / HDR recovery unit recovers the analog signal (N-1) that has been interfered with by performing an adjustment process that symmetrically copies the frequency domain of the interference-free region to the interference-occurring region, and recovers the LDS by subtracting the frequency domain of the copied interference-free region from the frequency domain of the interference-occurring region.

4. The preprocessing system according to claim 1, characterized in that, The data folding section utilizes the symmetry property of the analog signals (N-1, N+1) that interfere with the LDS and UDS of the analog signal (N) of the CDR or the HDR to divide the region into an interference-occurring region and an interference-free region with the center as a reference. The CDR / HDR recovery unit recovers the analog signal (N-1, N+1) that has been interfered with by performing an adjustment process that symmetrically copies the frequency domain of the interference-free region to the interference-occurring region, and recovers the LDS and the USD by subtracting the frequency domain of the copied interference-free region from the frequency domain of the interference-occurring region.

5. The preprocessing system according to claim 1, characterized in that, Also includes: The filter section allows only lower sideband signals with a center frequency lower than the center frequency of the RF signal in the selected channel, or only upper sideband signals with a center frequency higher than the center frequency. The CDR / HDR restoration unit performs beamforming on the selected channel based on the difference in gain between the signal that passed through the filter unit and the original signal that did not pass through the filter unit.

6. The preprocessing system according to claim 5, characterized in that, Also includes: A noise cancellation module that tracks and eliminates noise included in the RF signal of the CDR or HDR received from the CDR / HDR RF receiver. The noise cancellation module includes: The noise detection unit performs a fast Fourier transform on the RF signal of the CDR or the HDR to the frequency domain and detects noise from the signal after the fast Fourier transform. as well as The feedforward active noise control unit eliminates the noise detected by the noise detection unit, performs a fast inverse Fourier transform on the RF signal of the CDR or HDR after the noise has been eliminated to the time domain, and stores the signal after the fast inverse Fourier transform in a memory.

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