Preprocessing system for interference cancellation within adjacent range of analog signals of HDR and cdr

Abstract

A preprocessing system for interference cancellation within an adjacent range of analog signals of hybrid digital radio (HDR) and conventional digital radio (CDR) is disclosed. Provided in the present embodiment is the preprocessing system for interference cancellation within an adjacent range of analog signals of HDR and CDR, the system restoring symmetric properties in the process of receiving HDR and CDR, and additionally using FM phase properties of a signal so as to determine whether there is signal noise, thereby enabling cancellation, within adjacent ranges of analog signals, of interference in a single path without beam forming (2 paths or more).

Description

Preprocessing system for eliminating interference within the adjacent range of analog signals of HDR and CDR

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

[0002] The content described below merely provides background information related to the present embodiment and does not constitute prior art.

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

[0004] DAB (Digital Audio Broadcasting) is a European standard, DRM (Digital Radio Mondiale) is a third world standard, HDR is an American standard, and CDR is a Chinese standard.

[0005] HDR (Hybrid Digital Radio) is a radio broadcasting technology that provides a hybrid of analog and digital broadcasting. HD Radio (HDR) is a digital radio format manufactured under license by iBiquity Digital Corporation in the United States.

[0006] As shown in Figure 1, FM broadcasting in the United States transmits radio signals in 200 kHz increments. HDR uses a method of mixing existing FM (N) into digital (N) and transmitting it.

[0007] In other words, HDR transmits the same digital radio signal on both sidebands of an analog FM signal. HDR's LDS (Lower Digital Sideband) and UDS (Upper Digital Sideband) are symmetrical, and are designed to allow listening even if only one LDS or UDS is perfectly restored.

[0008] In the US, frequencies are managed so that neither side of the HDR digital signal is affected.

[0009] As illustrated in (a) of Figure 2, interference typically occurs within the adjacent range only in one sideband. When interference occurs within the adjacent range only in one sideband, the signal is restored using the signal from the other sideband that is not affected by the interference.

[0010] However, if the received signal of the adjacent channel is significantly greater than the received signal of the original channel, there is a problem in that the signal goes beyond the range of signals that can be expressed digitally, making signal restoration impossible.

[0011] As illustrated in (b) of Figure 2, when crossing borders or regions, both the Lower Digital Sideband (LDS) and the Upper Digital Sideband (UDS) experience degradation due to adjacent channels. When degradation occurs in both sidebands, not only does it result in degradation due to mobility, but it also presents a problem of difficulty in restoration due to the low SNR of the digital end in the adjacent channel.

[0012] The purpose of this embodiment is to provide a preprocessing system for removing interference within an adjacent range of analog signals of HDR and CDR, which restores the symmetric property in the process of receiving HDR (Hybrid Digital Radio) and CDR (Conventional Digital Radio), and additionally determines whether the signal is noisy by using the FM phase property of the signal, thereby removing interference within an adjacent range of analog signals with a single pass without beam forming (2 or more paths).

[0013] According to one aspect of the present embodiment, a preprocessing system is provided, comprising: a CDR / HDR RF receiver for receiving an RF signal of a CDR (Conventional Digital Radio) or an HDR (Hybrid Digital Radio); a data folding unit for recognizing interference as noise in a case where interference occurs in an UDS (Upper Digital Sideband) or an LDS (Lower Digital Sideband) within an adjacent range of an analog signal (N) of the CDR or the HDR, or interference occurs in both the UDS and the LDS, and using a symmetrical property of an analog signal (N-1, N+1) in which interference occurred, to divide the signal into symmetrical regions based on the center using a data folding method; and a CDR / HDR restoration unit for restoring a signal by removing the interference based on the symmetrical regions.

[0014] As described above, according to the present embodiment, in the process of receiving HDR (Hybrid Digital Radio) and CDR (Conventional Digital Radio), the symmetric property is restored, and additionally, the FM phase property of the signal is used to determine whether the signal is noisy, thereby eliminating interference within the adjacent range of the analog signal with a single pass without beam forming (2 or more paths).

[0015] Figures 1 and 2 are drawings for explaining HDR characteristics according to conventional technology.

[0016] FIG. 3 is a diagram illustrating a method of restoring interference to a UDS within an adjacent range of an analog signal using a data folding method according to the present embodiment.

[0017] FIG. 4 is a diagram showing the simulation results for a method of restoring interference to UDS within an adjacent range of an analog signal using a data folding method according to the present embodiment.

[0018] FIG. 5 is a diagram illustrating a method of restoring interference to LDS within an adjacent range of an analog signal using a data folding method according to the present embodiment.

[0019] FIG. 6 is a diagram illustrating a method for restoring interference in LDS and UDS within an adjacent range of an analog signal using a data folding method according to the present embodiment.

[0020] Figure 7 is a drawing showing the starting point of a data folding method according to the present embodiment.

[0021] Fig. 8 is a diagram showing the restoration process of HDR and CDR according to the present embodiment.

[0022] Hereinafter, the present embodiment will be described in detail with reference to the attached drawings.

[0023] FIG. 3 is a diagram illustrating a method of restoring interference to a UDS within an adjacent range of an analog signal using a data folding method according to the present embodiment.

[0024] When interference occurs in the UDS (Upper Digital Sideband) within the adjacent range of the analog signal (N) of the received CDR or HDR, the preprocessing system (800) recognizes it as noise and uses a data folding method to remove the interference that occurred in the UDS and restore the signal.

[0025] The preprocessing system (800) can recognize interference within the adjacent range of an analog signal (N) for a CDR having the same spectral structure as HDR as noise and restore the signal by removing the interference occurring in the adjacent range using a data folding method. Here, the preprocessing system (800) can also be applied to CDR differently from HDR in terms of spectral spacing, but the same concept as HDR can be applied to remove interference within the adjacent range of an analog signal.

[0026] The preprocessing system (800) receives an RF signal of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio).

[0027] When interference occurs with a UDS within the adjacent range of an analog signal (N) of a CDR or HDR, the preprocessing system (800) recognizes it as noise and selects an analog signal (N+1) that has interference with a UDS within the adjacent range of the analog signal (N).

[0028] The preprocessing system (800) uses the symmetrical property of the analog signal (N+1) that has interference with the UDS to divide it into two symmetrical regions (interference region (region ② of FIG. 3) and interference-free region (region ① of FIG. 3)) based on the center.

[0029] The preprocessing system (800) performs adjustment processing to symmetrically copy the frequency domain of the interference-free region (region ① of FIG. 3) among the two symmetric regions to the interference-occurring region (region ② of FIG. 3), thereby restoring the analog signal (N+1) of the adjacent channel where interference occurred.

[0030] The preprocessing system (800) restores the UDS by subtracting the frequency domain of the interference-free region from the frequency domain of the interference-occurring region.

[0031] FIG. 4 is a diagram showing the simulation results for a method of restoring interference to UDS within an adjacent range of an analog signal using a data folding method according to the present embodiment.

[0032] The preprocessing system (800) receives an RF signal of a Conventional Digital Radio (CDR) or a Hybrid Digital Radio (HDR). When interference occurs with a UDS within the adjacent range of an analog signal (N) of a CDR or HDR, the analog signal (N+1) that has interference with a UDS within the adjacent range of the analog signal (N) is as illustrated in (a) of Fig. 4.

[0033] The preprocessing system (800) utilizes the symmetrical properties of the analog signal (N+1) in which interference occurs with the UDS to separate it into two symmetrical regions based on the center. The UDS is restored by subtracting the frequency domain of the interference-free region from the frequency domain of the interference-free region, and the signal in which the analog signal (N+1) in which interference occurs is restored by performing an adjustment process that symmetrically copies the frequency domain of the interference-free region among the symmetrical regions to the interference-free region, as shown in (b) of FIG. 4.

[0034] FIG. 5 is a diagram illustrating a method of restoring interference to LDS within an adjacent range of an analog signal using a data folding method according to the present embodiment.

[0035] When interference occurs in the LDS (Lower Digital Sideband) within the adjacent range of the analog signal (N) of the received CDR or HDR, the preprocessing system (800) recognizes it as noise and uses a data folding method to remove the interference that occurred in the LDS and restore the signal.

[0036] The preprocessing system (800) can recognize interference within the adjacent range of an analog signal (N) for a CDR having the same spectral structure as HDR as noise and restore the signal by removing the interference occurring in the adjacent range using a data folding method. Here, the preprocessing system (800) can also be applied to CDR differently from HDR in terms of spectral spacing, but the same concept as HDR can be applied to remove interference within the adjacent range of an analog signal.

[0037] The preprocessing system (800) receives an RF signal of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio).

[0038] When interference occurs with an LDS within the adjacent range of an analog signal (N) of a CDR or HDR, the preprocessing system (800) recognizes it as noise and selects an analog signal (N-1) that has interference with an LDS within the adjacent range of the analog signal (N).

[0039] The preprocessing system (800) uses the symmetrical property of the analog signal (N-1) that has interference with the LDS to separate it into two symmetrical regions (interference region (region ② of FIG. 5) and interference-free region (region ① of FIG. 5)) based on the center.

[0040] The preprocessing system (800) performs adjustment processing to symmetrically copy the frequency domain of the interference-free region (region ① of FIG. 5) among the two symmetric regions to the interference-occurring region (region ② of FIG. 5), thereby restoring the analog signal (N-1) of the adjacent channel where interference occurred.

[0041] The preprocessing system (800) restores the LDS by subtracting the frequency domain of the interference-free region from the frequency domain of the interference-occurring region.

[0042] FIG. 6 is a diagram illustrating a method for restoring interference in LDS and UDS within an adjacent range of an analog signal using a data folding method according to the present embodiment.

[0043] When interference occurs in the LDS (Lower Digital Sideband) within the adjacent range of the analog signal (N) of the received CDR or HDR, the preprocessing system (800) recognizes it as noise and uses a data folding method to remove the interference that occurred in the LDS and restore the signal.

[0044] The preprocessing system (800) can recognize interference within the adjacent range of an analog signal (N) for a CDR having the same spectral structure as HDR as noise and restore the signal by removing the interference occurring in the adjacent range using a data folding method. Here, the preprocessing system (800) can also be applied to CDR differently from HDR in terms of spectral spacing, but the same concept as HDR can be applied to remove interference within the adjacent range of an analog signal.

[0045] The preprocessing system (800) receives an RF signal of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio).

[0046] When interference occurs with an LDS within the adjacent range of an analog signal (N) of a CDR or HDR, the preprocessing system (800) recognizes it as noise and selects an analog signal (N-1) that has interference with an LDS within the adjacent range of the analog signal (N).

[0047] The preprocessing system (800) uses the symmetrical property of the analog signal (N-1) that has interference with the LDS to separate it into two symmetrical regions (interference region (region ② of FIG. 6) and interference-free region (region ① of FIG. 5)) based on the center.

[0048] The preprocessing system (800) performs adjustment processing to symmetrically copy the frequency domain of the interference-free region (region ① of FIG. 6) among the two symmetric regions to the interference-occurring region (region ② of FIG. 6), thereby restoring the analog signal (N-1) of the adjacent channel where interference occurred.

[0049] The preprocessing system (800) restores the LDS by subtracting the frequency domain of the interference-free region from the frequency domain of the interference-occurring region.

[0050] When interference occurs with a UDS within the adjacent range of an analog signal (N) of a CDR or HDR, the preprocessing system (800) recognizes it as noise and selects an analog signal (N+1) that has interference with a UDS within the adjacent range of the analog signal (N).

[0051] The preprocessing system (800) uses the symmetrical property of the analog signal (N+1) that has interference with the UDS to separate it into two symmetrical regions (interference region (region ④ of FIG. 6) and interference-free region (region ③ of FIG. 6)) based on the center.

[0052] The preprocessing system (800) performs adjustment processing to symmetrically copy the frequency domain of the interference-free region (region ③ of FIG. 6) among the two symmetric regions to the interference-occurring region (region ④ of FIG. 6), thereby restoring the analog signal (N+1) of the adjacent channel where interference occurred.

[0053] The preprocessing system (800) restores the UDS by subtracting the frequency domain of the interference-free region from the frequency domain of the interference-occurring region.

[0054] Figure 7 is a drawing showing the starting point of a data folding method according to the present embodiment.

[0055] The preprocessing system (800) can utilize various noise extraction methods. The preprocessing system (800) can additionally determine whether a signal contains noise by utilizing the FM phase property of a signal restored with a symmetric property.

[0056] The preprocessing system (800) is not limited to FB-ANC (Feedback Active Noise Cancellation) and can be configured with only FF-ANC (Feed Forward Active Noise Cancellation), and as a technology that can use FB-ANC as an auxiliary, artificial intelligence-based noise removal is possible.

[0057] The preprocessing system (800) can estimate noise using artificial intelligence.

[0058] The preprocessing system (800) extracts feature points from each of the nth audio signal and the subsequent audio signals (n+1, n+2, n+3) stored in memory after the nth audio signal.

[0059] The preprocessing system (800) generates coordinate information for the locations where the extracted feature points are formed in the frequency domain. The preprocessing system (800) inputs the coordinate information for each of the generated feature points as input values ​​to a pre-trained artificial neural network. Here, the artificial neural network includes a deep neural network composed of an input layer, a hidden layer, and an output layer.

[0060] The preprocessing system (800) estimates the noise signal included in the audio signal input for the next signal processing based on the output value of the artificial neural network.

[0061] The preprocessing system (800) predicts the location of the next occurrence of coordinate information through the artificial neural network based on the movement pattern of coordinate information for feature points input to the artificial neural network. The preprocessing system (800) extracts a noise signal having a frequency characteristic corresponding to the predicted occurrence location from the audio signal.

[0062] The preprocessing system (800) calculates the similarity between the noise signal predicted by the artificial neural network and the noise signal actually detected by the noise detection unit. The preprocessing system (800) adjusts the weights between the nodes constituting the artificial neural network based on the calculated similarity.

[0063] For example, the preprocessing system (800) calculates the similarity between the signal pattern of the noise signal predicted by the artificial neural network and the signal pattern of the noise signal actually detected by the noise detection unit. If the calculated similarity is lower than a preset reference similarity, the preprocessing system (800) adjusts the weights between the nodes constituting the artificial neural network until the similarity is higher than the reference similarity.

[0064] The preprocessing system (800) can predict noise included in an audio signal using an artificial neural network, and can improve noise removal performance by additionally removing noise not detected by the noise detection unit.

[0065] The preprocessing system (800) can determine noise using a data folding method when noise occurs in the LDS (Lower Digital Sideband) within the adjacent range of the analog signal (N) of the received CDR or HDR.

[0066] Hereinafter, a method for determining noise occurring within an adjacent range of an analog signal (N) of CDR or HDR based on (a) of Fig. 7 is described.

[0067] As shown in (a) of FIG. 7, the preprocessing system (800) receives an RF signal of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio).

[0068] The preprocessing system (800) selects a signal (N-1) in which noise has occurred within the adjacent range of the analog signal (N) of CDR or HDR, when LDS and noise have occurred within the adjacent range of the analog signal (N).

[0069] The preprocessing system (800) uses the symmetrical property of the signal (N-1) in which noise has occurred to separate it into two symmetrical regions (noise generation region (region ② of FIG. 7) and noise-free region (region ① of FIG. 7)) based on the center.

[0070] The preprocessing system (800) performs adjustment processing to symmetrically copy the frequency domain of the noise-free region (region ① of Fig. 7 (a)) among the two symmetric regions to the noise-generating region (region ② of Fig. 7 (a)), thereby restoring the analog signal (N-1) of the adjacent channel where noise occurred.

[0071] The preprocessing system (800) separates only the noise in the frequency domain by subtracting the signal in the noise-free area from the signal in the noise-generating area.

[0072] Hereinafter, a method for ignoring negative values ​​in the frequency domain for noise occurring within an adjacent range of an analog signal (N) of CDR or HDR based on (b) of Fig. 7 is described.

[0073] As shown in (b) of Fig. 7, the preprocessing system (800) selects a signal (N-1) in which noise has occurred within the adjacent range of the analog signal (N) of CDR or HDR when LDS and noise have occurred within the adjacent range of the analog signal (N).

[0074] The preprocessing system (800) uses the symmetrical property of the signal (N-1) in which noise has occurred to separate it into two symmetrical regions (noise-generated region (region ③ of Fig. 7 (b)) and noise-free region (region ④ of Fig. 7 (b))) based on the center.

[0075] The preprocessing system (800) performs adjustment processing to symmetrically copy the frequency domain of the noise-generating region (region ③ of Fig. 7 (b)) among the two symmetrical regions to the noise-free region (region ④ of Fig. 7 (b)), thereby generating a symmetrical noise-generating region signal.

[0076] The preprocessing system (800) subtracts the signal of the symmetrical noise generation area from the signal of the noise generation area. The preprocessing system (800) subtracts the signal of the symmetrical noise generation area from the noise generation area so that the noise is canceled out, and outputs a negative value for the symmetrical noise from the noise-free area.

[0077] The preprocessing system (800) ignores negative values ​​for symmetrical noise in the frequency domain.

[0078] The preprocessing system (800) separates only the noise in the frequency domain by subtracting a signal having a negative value for symmetrical noise in the frequency domain from a signal from which only the noise in the frequency domain has been separated.

[0079] Fig. 8 is a diagram showing the restoration process of HDR and CDR according to the present embodiment.

[0080] The preprocessing system (800) performs MRC preprocessing using a beamforming method to eliminate interference within the adjacent range of the CDR / HDR analog signal.

[0081] The preprocessing system (800) applies a filter to the sideband of a channel selected during the reception process of digital radio and forms RF beam forming by utilizing the gain difference of automatic gain control (AGC). It is preferable to implement the preprocessing system in a vehicle radio receiving device, but is not necessarily limited thereto.

[0082] The preprocessing system (800) is capable of eliminating interference within the adjacent range of an analog signal in a single pass without beamforming (two or more paths). The preprocessing system (800) corrects the uncertainty of the analog co-channel residual offset tracking from the RF signal of the CDR or HDR by reflecting a weight.

[0083] The preprocessing system (800) has a structure that combines beamforming and data folding. The preprocessing system (800) has a structure that simultaneously obtains gain by processing the gain restored by analog co-channel and beamforming using the data folding method (1 path).

[0084] The preprocessing system (800) additionally includes a noise removal module (not shown) that tracks and removes noise included in the RF signal of the CDR or HDR received from the first CDR / HDR RF receiver (810) or the second CDR / HDR RF receiver (830).

[0085] The noise removal module includes a noise detection unit (not shown) that performs fast Fourier transform on the RF signal of the CDR or HDR in the frequency domain and detects noise from the fast Fourier transformed signal, a feed forward ANC (Active Noise Cancellation) unit (not shown) that removes noise detected by the noise detection unit, performs inverse fast Fourier transform on the RF signal of the CDR or HDR from which noise has been removed in the time domain, and stores the inverse fast Fourier transformed signal in a memory.

[0086] The preprocessing system (800) according to the present embodiment includes a first CDR / HDR RF receiver (810), a data folding unit (820), a second CDR / HDR RF receiver (830), a filter unit (840), an adjacent filter controller (850), and a CDR / HDR restoration unit (860). The components included in the preprocessing system (800) are not necessarily limited thereto.

[0087] The first CDR / HDR RF receiver (810) receives an RF signal of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio).

[0088] When interference occurs in the UDS (Upper Digital Sideband) or LDS (Lower Digital Sideband) within the adjacent range of the analog signal (N) of the received CDR or HDR, or interference occurs in both the UDS and LDS, the data folding unit (820) recognizes it as noise and uses the data folding method to remove the interference that occurred in the UDS and restore the signal.

[0089] The data folding unit (820) uses the symmetrical property of the analog signal (N+1) where interference occurs with the UDS of the analog signal (N) of the CDR or HDR to separate the interference-occurring area and the interference-free area based on the center.

[0090] The data folding unit (820) uses the symmetrical property of the LDS of the analog signal (N) of the CDR or HDR and the analog signal (N-1) where interference occurs to separate the LDS into an interference area and an interference-free area based on the center.

[0091] The data folding unit (820) uses the symmetrical properties of the LDS and UDS of the analog signal (N) of the CDR or HDR and the analog signal (N-1, N+1) that has interference to separate the signal into an interference area and an interference-free area based on the center.

[0092] When interference occurs in the UDS or LDS within the adjacent range of the analog signal (N) of the CDR or HDR, or interference occurs in both the UDS and LDS, the data folding unit (820) recognizes it as noise and uses the symmetrical property of the analog signal (N-1, N+1) where interference occurred to divide it into symmetrical areas based on the center using the data folding method.

[0093] Hereinafter, a method for restoring a signal by removing interference that occurs in the UDS using the data folding unit (820) and the CDR / HDR restoration unit (860) will be described.

[0094] When interference occurs in the UDS (Upper Digital Sideband) within the adjacent range of the analog signal (N) of the received CDR or HDR, the data folding unit (820) recognizes it as noise and uses the data folding method to remove the interference that occurred in the UDS and restore the signal.

[0095] The data folding unit (820) receives an RF signal of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio).

[0096] When interference occurs with a UDS within the adjacent range of an analog signal (N) of CDR or HDR, the data folding unit (820) recognizes it as noise and selects an analog signal (N+1) that has interference with a UDS within the adjacent range of the analog signal (N).

[0097] The data folding unit (820) uses the symmetrical property of the analog signal (N+1) that has interference with the UDS to separate it into two symmetrical areas (interference area, interference-free area) based on the center.

[0098] The CDR / HDR restoration unit (860) performs adjustment processing to symmetrically copy the frequency domain of the interference-free region among the two symmetric regions to the interference-occurring region, thereby restoring the analog signal (N+1) of the adjacent channel where interference occurred.

[0099]

[0100] *The CDR / HDR restoration unit (860) restores the UDS by subtracting the frequency domain of the interference-free area from the frequency domain of the interference-occurring area.

[0101] Hereinafter, a method for restoring a signal by removing interference that occurs in LDS using a data folding unit (820) and a CDR / HDR restoration unit (860) is described.

[0102] When interference occurs in the LDS (Lower Digital Sideband) within the adjacent range of the analog signal (N) of the received CDR or HDR, the data folding unit (820) recognizes it as noise and uses the data folding method to remove the interference that occurred in the LDS and restore the signal.

[0103] The data folding unit (820) receives an RF signal of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio).

[0104] When interference occurs with an LDS within the adjacent range of an analog signal (N) of a CDR or HDR, the data folding unit (820) recognizes it as noise and selects an analog signal (N-1) that has interference with an LDS within the adjacent range of the analog signal (N).

[0105] The data folding unit (820) uses the symmetrical property of the analog signal (N-1) that has interference with the LDS to separate it into two symmetrical regions (interference region, interference-free region) based on the center.

[0106] The CDR / HDR restoration unit (860) performs adjustment processing to symmetrically copy the frequency domain of the interference-free region among the two symmetric regions to the interference-occurring region, thereby restoring the analog signal (N-1) of the adjacent channel where interference occurred.

[0107]

[0108] *The CDR / HDR restoration unit (860) restores the LDS by subtracting the frequency domain of the interference-free area copied from the frequency domain of the interference-occurring area.

[0109] Hereinafter, a method for restoring a signal by removing interference that occurs in LDS and UDS using a data folding unit (820) and a CDR / HDR restoration unit (860) is described.

[0110] When interference occurs in the LDS (Lower Digital Sideband) within the adjacent range of the analog signal (N) of the received CDR or HDR, the data folding unit (820) recognizes it as noise and uses the data folding method to remove the interference that occurred in the LDS and restore the signal.

[0111] The data folding unit (820) receives an RF signal of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio).

[0112] When interference occurs with an LDS within the adjacent range of an analog signal (N) of a CDR or HDR, the data folding unit (820) recognizes it as noise and selects an analog signal (N-1) that has interference with an LDS within the adjacent range of the analog signal (N).

[0113] The data folding unit (820) uses the symmetrical property of the analog signal (N-1) that has interference with the LDS to separate it into two symmetrical regions (interference region, interference-free region) based on the center.

[0114] The CDR / HDR restoration unit (860) performs adjustment processing to symmetrically copy the frequency domain of the interference-free region among the two symmetric regions to the interference-occurring region, thereby restoring the analog signal (N-1) of the adjacent channel where interference occurred.

[0115] The CDR / HDR restoration unit (860) restores the LDS by subtracting the frequency domain of the interference-free region from the frequency domain of the interference-occurring region.

[0116] When interference occurs with a UDS within the adjacent range of an analog signal (N) of CDR or HDR, the data folding unit (820) recognizes it as noise and selects an analog signal (N+1) that has interference with a UDS within the adjacent range of the analog signal (N).

[0117] The data folding unit (820) uses the symmetrical property of the analog signal (N+1) that has interference with the UDS to separate it into two symmetrical areas (interference area, interference-free area) based on the center.

[0118] The CDR / HDR restoration unit (860) performs adjustment processing to symmetrically copy the frequency domain of the interference-free region among the two symmetric regions to the interference-occurring region, thereby restoring the analog signal (N+1) of the adjacent channel where interference occurred.

[0119]

[0120] *The CDR / HDR restoration unit (860) restores the UDS by subtracting the frequency domain of the interference-free area from the frequency domain of the interference-occurring area.

[0121] The second CDR / HDR RF receiver (830) receives an RF signal of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio).

[0122] The filter unit (840) passes only the low side band signal lower than the center frequency of the RF signal of the CDR or HDR in the selected channel, or passes only the upper side band signal higher than the center frequency.

[0123] The filter unit (840) includes a 1-1 filter, a 1-2 filter, a 2-1 filter, and a 2-2 filter.

[0124] The filter unit (840) includes a plurality of filters that pass only frequencies of a specific band and can selectively extract signals under the control of the adjacent filter controller (850).

[0125] The filter unit (840) passes only the low side band signal lower than the center frequency of the radio signal in the selected channel or passes only the up side band signal higher than the center frequency of the radio signal by using any one of the 1-1 filter, 1-2 filter, 2-1 filter, and 2-2 filter.

[0126] When the filter unit (840) has the characteristics of a 2-1 filter, it can amplify the signal by transferring the total energy of the FM and N+1 adjacent signals of the original signal to the LDS.

[0127] When the filter unit (840) has the characteristics of a 2-2 filter, it can amplify the signal by transferring the total energy of the FM and N-1 adjacent signals of the original signal to the UDS.

[0128] When the filter unit (840) has the characteristics of a 1-1 filter, it can divide and transmit the FM and (N+1 / N-1 adjacent) portions of energy of the original signal to LDS and UDS.

[0129] When the filter unit (840) has the characteristics of a 1-2 filter, it can transfer the FM of the original signal and some of the energy of (N+1 / N-1 adjacent) signals to the original signal.

[0130] The adjacent filter controller (850) controls the filter unit (840) to select one of the 1-1 filter, 1-2 filter, 2-1 filter, and 2-2 filter.

[0131] The CDR / HDR restoration unit (860) restores the signal by removing interference based on the symmetrical area.

[0132] The CDR / HDR restoration unit (860) performs beamforming for a selected channel based on the difference in gain values ​​between the signal that passed through the filter unit (840) and the original signal that did not pass through the filter unit (840). The CDR / HDR restoration unit (860) performs beamforming and restores the signal by utilizing the gain difference of automatic gain control (AGC).

[0133] The CDR / HDR restoration unit (860) processes signals using the MRC (Maximum Ratio Combining) algorithm. The MRC algorithm refers to a technique that weights the good portion of a channel when the maximum amount is created by adjusting the phase.

[0134] The CDR / HDR restoration unit (860) can restore the LDS from the LDS and the LDS adjacent signal. The CDR / HDR restoration unit (860) can restore the UDS from the UDS and the UDS adjacent signal. The CDR / HDR restoration unit (860) can reflect the CSI (Channel status information) channel weight with a low probability as much as the frequency offset (as much as the overlapping occurred) that occurred in the FM phase tracking.

[0135] The CDR / HDR restoration unit (860) restores the analog signal (N+1) in which interference occurred by performing an adjustment process that symmetrically copies the frequency domain of the interference-free region to the interference-occurring region, and restores the UDS by subtracting the frequency domain of the interference-free region copied from the frequency domain of the interference-occurring region.

[0136] The CDR / HDR restoration unit (860) performs adjustment processing to symmetrically copy the frequency domain of the interference-free region to the interference-occurring region, thereby restoring the analog signal (N-1) in which interference occurred, and subtracts the frequency domain of the interference-free region copied from the frequency domain of the interference-occurring region to restore the LDS.

[0137] The CDR / HDR restoration unit (860) performs adjustment processing to symmetrically copy the frequency domain of the interference-free region to the interference-occurring region, thereby restoring the analog signal (N-1, N+1) in which interference occurred, and subtracts the frequency domain of the interference-free region copied from the frequency domain of the interference-occurring region to restore the LDS and UDS.

[0138] The CDR / HDR restoration unit (860) performs beamforming for a selected channel based on the difference in gain values ​​between the signal that passed through the filter unit (840) and the original signal that did not pass through the filter unit (840).

[0139] The above description is merely an example of the technical idea of ​​the present embodiment, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present embodiment. Therefore, the present embodiments are not intended to limit the technical idea of ​​the present embodiment, but rather to explain 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 by the claims below, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of rights of the present embodiment.

[0140] The mode for carrying out the invention has been described together with the best mode for carrying out the invention above.

[0141] The present invention has industrial applicability because it can remove interference within an adjacent range of an analog signal with a single pass without beam forming (two or more paths).

Claims

1. CDR / HDR RF receiver that receives RF signals of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio); When interference occurs in the UDS (Upper Digital Sideband) or LDS (Lower Digital Sideband) within the adjacent range of the analog signal (N) of the CDR or HDR, or when interference occurs in both the UDS and the LDS, a data folding unit that recognizes it as noise and divides it into symmetrical areas based on the center by using the symmetrical property of the analog signal (N-1, N+1) in which interference occurred using a data folding method; A CDR / HDR restoration unit that restores a signal by removing the interference based on the above symmetrical area; The above data folding section uses the symmetrical property of the analog signal (N+1) that has interference with the UDS of the analog signal (N) of the CDR or the HDR to separate the interference-occurring area and the interference-free area based on the center. A preprocessing system characterized in that the CDR / HDR restoration unit restores the analog signal (N+1) in which interference occurred by performing adjustment processing to symmetrically copy the frequency domain of the interference-free region to the interference-occurring region, and restores the UDS by subtracting the frequency domain of the interference-free region copied from the frequency domain of the interference-occurring region.

2. CDR / HDR RF receiver that receives RF signals of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio); When interference occurs in the UDS (Upper Digital Sideband) or LDS (Lower Digital Sideband) within the adjacent range of the analog signal (N) of the CDR or HDR, or when interference occurs in both the UDS and the LDS, a data folding unit that recognizes it as noise and divides it into symmetrical areas based on the center by using the symmetrical property of the analog signal (N-1, N+1) in which interference occurred using a data folding method; A CDR / HDR restoration unit that restores a signal by removing the interference based on the above symmetrical area; The above data folding section uses the symmetrical property of the analog signal (N-1) that has interference with the LDS of the analog signal (N) of the CDR or the HDR to separate the LDS into an interference area and an interference-free area based on the center. A preprocessing system characterized in that the CDR / HDR restoration unit restores the analog signal (N-1) in which interference occurred by performing adjustment processing to symmetrically copy the frequency domain of the interference-free region to the interference-occurring region, and restores the LDS by subtracting the frequency domain of the interference-free region copied from the frequency domain of the interference-occurring region.

3. CDR / HDR RF receiver for receiving RF signals of CDR (Conventional Digital Radio) or HDR (Hybrid Digital Radio); When interference occurs in the UDS (Upper Digital Sideband) or LDS (Lower Digital Sideband) within the adjacent range of the analog signal (N) of the CDR or HDR, or when interference occurs in both the UDS and the LDS, a data folding unit that recognizes it as noise and divides it into symmetrical areas based on the center by using the symmetrical property of the analog signal (N-1, N+1) in which interference occurred using a data folding method; A CDR / HDR restoration unit that restores a signal by removing the interference based on the above symmetrical area; The above data folding section uses the symmetrical property of the analog signal (N-1, N+1) that interferes with the LDS and the UDS of the analog signal (N) of the CDR or the HDR to separate the interference-occurring area and the interference-free area based on the center. A preprocessing system characterized in that the CDR / HDR restoration unit restores the analog signal (N-1, N+1) in which interference occurred by performing adjustment processing to symmetrically copy the frequency domain of the interference-free region to the interference-occurring region, and restores the LDS and the UDS by subtracting the frequency domain of the interference-free region copied from the frequency domain of the interference-occurring region.

4. In paragraph 1, A filter section that passes only a low side band signal lower than the center frequency of the RF signal of the CDR or HDR in the selected channel or passes only an upper side band signal higher than the center frequency; In addition, it includes A preprocessing system characterized in that the CDR / HDR restoration unit performs beamforming for a selected channel based on the difference in gain values ​​between a signal that has passed through the filter unit and an original signal that has not passed through the filter unit.

5. In paragraph 4, A noise removal module that tracks and removes noise included in the RF signal of the CDR or HDR received from the CDR / HDR RF receiver. In addition, it includes: The above noise removal module A noise detection unit that performs fast Fourier transform on the RF signal of the CDR or HDR in the frequency domain and detects noise from the fast Fourier transformed signal; and A feed forward ANC (Active Noise Cancellation) unit that removes noise detected by the noise detection unit, inversely fast Fourier transforms the RF signal of the CDR or HDR from which the noise has been removed into a time domain, and stores the inversely fast Fourier transformed signal in a memory; A pre-processing system characterized by including:

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