Interference Cancellation Device and Interference Cancellation Method for 5G ICS Repeater

Abstract

To provide a technique relating to an ICS repeater usable in a wireless network, more specifically, effectively removing only an interference signal by selectively using an autocorrelation remover in the ICS repeater.SOLUTION: An interference removing method performed by a 5G ICS repeater may comprise the steps of: obtaining a first error signal from which a first predicted feedback signal is removed from a first original signal received through a reception antenna; generating a first delay signal by delaying the first error signal; determining whether or not the first original signal is a null signal based on amplitude information of the first error signal; determining a first reference signal based on the first delay signal according to a result of determining whether the first original signal is a null signal; and generating a second predicted feedback signal based on the first reference signal.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an ICS repeater that can be used in a wireless network, and more particularly to a technique for effectively removing only interference signals by selectively using an autocorrelation canceller in an ICS repeater {APPARATUS, AND METHODS FOR CANCELLING INTERFERENCE FOR 5G ICS REPEATER}.

Background Art

[0002] Generally, an ICS repeater is a system for solving the oscillation problem caused by the feedback signal generated between the transmission and reception antennas in a wireless repeater. More specifically, an interference cancellation technique is applied to an existing wireless repeater to predict the feedback signal, and this is subtracted from the input original signal to remove the feedback signal. It is a wireless repeater to which a technique for removing the feedback signal is applied.

[0003] The interference cancellation engine unit of an adaptive ICS repeater that uses an interference cancellation method using a general adaptive algorithm is located between the transmission antenna and the reception antenna, and is composed of a delay unit, a coefficient generation unit, and an FIR filter. The original signal d(n) = s(n) + y(n) received via the reception antenna outputs an error signal e(n) from which the interference signal has been removed via a subtractor. At this time, the coefficient generation unit (Coefficient generatior) of the interference cancellation engine unit calculates the correlation between the error signal e(n) from which the interference signal has been removed via the subtractor and the reference signal x(n) delayed by a certain time via the delay unit to calculate the interference signal prediction coefficient w(n). The interference signal prediction coefficient w(n) is convolved with the reference signal x(n) via an FIR filter to generate a predicted feedback signal y'(n) of the same phase, and the predicted feedback signal y'(n) is subtracted from the original signal via the subtractor 21 to output a signal from which the interference signal has been removed to the transmission antenna 30 side.

[0004] An adaptive ICS repeater that uses such an interference cancellation method using an adaptive algorithm generally uses the LMS (Least Mean Squared) or RLS (Recursive Least Square) adaptive algorithm. Such an adaptive algorithm uses the correlation between the error signal e(n) and the reference signal x(n) to predict the feedback signal and generate a feedback signal in phase. Therefore, it has different interference cancellation capabilities depending on the characteristics of the input signal source.

[0005] In particular, when narrowband signals such as the subcarrier part of 5G, LTE, or OFDM signals and narrowband signals such as NB-IOT are input, the interference signal cannot be effectively removed due to the autocorrelation characteristics of the input signal, and rather, unnecessary noise signals are generated.

[0006] In order to solve such problems, in other prior arts, as an interference cancellation method of an ICS repeater using an autocorrelation canceller, it is disclosed in Korean Patent Publication No. 10-2013-0054305 (Interference Cancellation Method of an ICS Repeater).

[0007] Also, it is a configuration diagram of another ICS repeater to which a prior art autocorrelation canceller is applied. Such a prior art is a method of removing narrowband signals in the feedback signal as a method of using an autocorrelation canceller, leaving only the broadband white noise component and using this as the reference signal x(n). Although the prediction and removal of the feedback signal are possible without being affected by the correlation characteristics of the narrowband signal, since the reference signal x(n) is in a state where the narrowband signal is removed and only white noise remains, the signal level becomes weak, and ultimately there is a problem that the adaptation speed for calculating the prediction coefficient w(n) becomes slow.

[0008] In order to overcome this, there are cases where a weak signal is amplified and used. However, in such cases, since noise is amplified to create a new reference signal x'(n) when there is no signal (white noise) input, there is a problem of distorting the SNR of the repeater output signal, thereby increasing unnecessary noise on the base station receiving side and reducing the capacity of the base station.

[0009] In addition, in other prior arts, as an ICS repeater and interference cancellation method using a selective equalizer, it is disclosed in Korean Registered Patent No. 10-2203955 (Interference Cancellation Method of ICS Repeater Using Selective Equalizer).

[0010] It is a configuration diagram of an interference cancellation device for an ICS repeater using a prior art selective equalizer. Such a prior art converts the time-axis data of an input signal into frequency-axis data using an equalizer, normalizes the magnitude of the converted data, and converts the normalized data back to the time axis to obtain a new normalized reference signal x'(n).

[0011] Such a method can predict and remove feedback signals without being affected by the correlation characteristics of narrowband signals. However, in a broadband wireless network such as 5G, when converting the time-axis data of an input signal into frequency-axis data, normalizing the magnitude of the converted data, and converting the normalized data back to the time axis, a delay more than five times that of LTE occurs. Such a delay has the problem of making it impossible to design an ICS repeater suitable for a 5G network.

Summary of the Invention

Problems to be Solved by the Invention

[0012] In view of the problems of the prior art as described above, the present invention does not always use an autocorrelation canceller to remove unnecessary noise signals generated by narrowband signals, but selectively uses an autocorrelation canceller to effectively remove only interference signals not only when there is a narrowband signal but also when there is a no-signal (white noise) input. The purpose is to provide an interference cancellation technology.

[0013] Furthermore, the present invention aims to provide an interference cancellation technology for an ICS repeater that satisfies the delay that can also be used in broadband wireless networks such as 5G.

Means for Solving the Problems

[0014] According to one aspect of the present invention, the interference cancellation method performed by a 5G ICS repeater includes: obtaining a first error signal from which a first predicted feedback signal is removed from a first original signal received via a receiving antenna; generating a first delayed signal by delaying the first error signal; determining whether the first original signal is a signal-free signal based on the amplitude information of the first error signal; determining a first reference signal based on the first delayed signal according to the signal-free determination result of the first original signal; and generating a second predicted feedback signal based on the first reference signal.

[0015] In one embodiment, the interference cancellation method of the 5G ICS repeater may further include generating a second error signal by removing a second predicted feedback signal from a second original signal received via a receiving antenna.

[0016] In one embodiment, in the step of determining the first reference signal, when it is determined that the first original signal is a signal-free signal, the first delayed signal may be selected as the first reference signal.

[0017] In one embodiment, in the step of determining the first reference signal, when it is determined that the first original signal is not a signal-free signal, the characteristics of the narrowband signal are removed from the first delayed signal to generate a first narrowband removal signal, and the first narrowband removal signal may be selected as the first reference signal.

[0018] In one embodiment, the step of determining whether the first original signal is a signal-free signal includes: obtaining amplitude information through envelope detection of the first error signal or the first delayed signal; and determining that the first original signal is a signal-free signal when the amplitude information is less than a preset reference amplitude size, or determining that the first original signal is not a signal-free signal when the amplitude information is greater than or equal to the preset reference amplitude size.

[0019] In one embodiment, the preset reference amplitude size can be set based on the result of measuring the first original signal when no signal is input to the 5G ICS repeater.

[0020] In one embodiment, the step of generating the second predicted feedback signal may include: calculating a first interference signal prediction coefficient based on the correlation between the first error signal and the first reference signal; and performing a convolution operation between the first delayed signal and the first interference signal prediction coefficient to generate the second predicted feedback signal.

[0021] According to another aspect of the present invention, a method for removing interference in a 5G ICS repeater may include: obtaining a first error signal from which a first predicted feedback signal has been removed from a first original signal received via a receiving antenna; delaying the first error signal to generate a first delayed signal; removing the characteristics of a narrowband signal from the first delayed signal to generate a first narrowband removed signal; determining whether the first original signal is a no-signal based on the amplitude information of the first error signal; determining either the first delayed signal or the first narrowband removed signal as the first reference signal according to the no-signal determination result of the first original signal; and generating a second predicted feedback signal based on the first reference signal.

[0022] According to still another aspect of the present invention, an interference removal apparatus for a 5G ICS repeater may include: a time delay unit that delays a first error signal from which a first predicted feedback signal has been removed from a first original signal received via a receiving antenna to generate a first delayed signal; a reference signal determination unit that determines whether the first original signal is a no-signal based on the amplitude information of the first error signal and determines a first reference signal based on the first delayed signal according to the determination result; and a predicted feedback signal generation unit that generates a second predicted feedback signal based on the first reference signal.

[0023] According to another aspect of the present invention, an interference cancellation device for a 5G ICS repeater may include a time delay unit that delays a first error signal obtained by removing a first predicted feedback signal from a first original signal received via a reception antenna to generate a first delayed signal; an autocorrelation canceller that removes the characteristics of a narrowband signal from the first delayed signal to generate a first narrowband removed signal; a reference signal selector that determines whether the first original signal is a no-signal based on the amplitude information of the first error signal and selects either the first delayed signal or the first narrowband removed signal as a first reference signal according to the determination result; and a predicted feedback signal generator that generates a second predicted feedback signal based on the first reference signal.

Advantages of the Invention

[0024] According to one aspect of the present invention, instead of constantly using an autocorrelation canceller to remove unnecessary noise signals generated by narrowband signals, by selectively using the autocorrelation canceller, it becomes possible to effectively remove only interference signals not only when there is a narrowband signal but also when there is a no-signal (white noise) input.

[0025] Furthermore, according to another aspect of the present invention, it becomes possible to remove interference signals of an ICS repeater that satisfies the delay that can also be used in a broadband wireless network such as 5G.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0027] The advantages and features of the present invention, as well as the methods for achieving them, will become apparent by referring to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and can be implemented in various forms. Merely, these embodiments are provided to make the disclosure of the present invention complete and to fully inform those with ordinary knowledge in the technical field to which the present invention pertains of the scope of the invention. The scope of the present invention is only defined by the claims.

[0028] In describing the embodiments of the present invention, specific descriptions of well-known functions or configurations are omitted unless actually necessary in describing the embodiments of the present invention. And the terms described later are terms defined in consideration of the functions in the embodiments of the present invention, which may vary according to the intentions or conventions of users, operators, etc. Therefore, the definitions should be made based on the content throughout this specification.

[0029] Terms such as "~ part" and "~ device" used below mean a unit that processes at least one function or operation, which can be realized by hardware, software, or a combination of hardware and software.

[0030] FIG. 1 is a block diagram of an interference cancellation device of a 5G ICS repeater according to an embodiment of the present invention.

[0031] Referring to FIG. 1, an interference cancellation device 1000 of a 5G ICS repeater according to an embodiment of the present invention may include a subtractor 1100, a time delay unit 1200, an autocorrelation canceller 1300, a reference signal determination unit 1400, and a predictive feedback signal generation unit 1500.

[0032] The subtractor 1100 can generate an error signal from which interference (predictive feedback signal) is removed from the original signal acquired using the receiving antenna 4100 of the 5G ICS repeater.

[0033] In one embodiment, the original signal can include a signal transmitted from a transmission end at a base station or the like and a feedback signal in which a signal transmitted from a transmission antenna of the 5G ICS repeater is received again by the reception antenna 4100 of the 5G ICS repeater.

[0034] The time delay unit 1200 can generate a delayed signal by delaying the error signal.

[0035] In one embodiment, the time delay unit 1200 can delay the error signal by a preset time.

[0036] In one embodiment, the preset time can be set to vary depending on the specifications of the 5G ICS repeater, its application (such as the frequency of the signal to be relayed), the delay, the user, and so on.

[0037] The autocorrelation eliminator 1300 can generate a narrowband removal signal by removing the characteristics of the narrowband signal from the delayed signal.

[0038] In one embodiment, the autocorrelation eliminator 1300 can generate a narrowband removal signal when it is determined that the original signal is not a null signal.

[0039] The reference signal determination unit 1400 can determine whether the original signal is a null signal based on the amplitude information of the error signal, and can determine a reference signal based on the delayed signal according to the determination result. For this purpose, it can include an amplitude information generator 1410 and a reference signal selection unit 1420.

[0040] The amplitude information generator 1410 can obtain amplitude information through envelope detection of the error signal or the delayed signal.

[0041] In one embodiment, the amplitude information can include the amplitude size of the original signal and so on.

[0042] In one embodiment, the amplitude information generator 1410 can perform envelope detection by making the error signal or the delay signal positive (taking the absolute value) and passing the positive signal through a low-pass filter.

[0043] The reference signal selection unit 1420 can determine whether the original signal is a no-signal based on the amplitude information, and select either the error signal or the delay signal as the reference signal according to the determination result.

[0044] In one embodiment, when the amplitude information is less than a preset reference amplitude size, the reference signal selection unit 1420 can determine that the original signal is a no-signal.

[0045] In one embodiment, when the amplitude information is greater than or equal to a preset reference amplitude size, the reference signal selection unit 1420 can determine that the original signal is not a no-signal.

[0046] In one embodiment, the preset reference amplitude size can be set based on the result of measuring the original signal when no signal is input to the 5G ICS repeater. Here, the preset reference amplitude size is a value for distinguishing between a signal and a no-signal, and can be set differently for each ICS repeater. An amplitude size for determining whether it is a no-signal can be set based on the result of measuring the amplitude size in the no-signal state. Generally, in order to process a digital signal in a repeater, the RF signal is converted into an IF signal, and the digital signal is processed through the process of converting the IF signal into sampled data again using an ADC. At this time, since the gain when converting the RF signal into the IF signal may be different for each ICS repeater, the preset reference amplitude size can be set differently for each ICS repeater. That is, when the gain when converting the RF signal into the IF signal is large, the preset reference amplitude size can be set large.

[0047] In one embodiment, when it is determined that the original signal is a no-signal, the reference signal selection unit 1420 can select the delayed signal as the reference signal.

[0048] In one embodiment, when it is determined that the original signal is not a no-signal, the reference signal selection unit 1420 can generate a narrowband removal signal by removing the characteristics of the narrowband signal from the delayed signal, and select the narrowband removal signal as the reference signal.

[0049] The prediction feedback signal generation unit 1500 can generate a prediction feedback signal based on the reference signal, and for this purpose, can include a coefficient generator 1510 and a FIR filter 1520.

[0050] The coefficient generator 1510 can calculate an interference signal prediction coefficient based on the correlation between the error signal and the reference signal.

[0051] The FIR filter 1520 can perform a convolution operation between the delayed signal and the interference signal prediction coefficient to generate a new prediction feedback signal.

[0052] In addition, since the present invention is for selectively applying an autocorrelation remover to improve the problems of the prior art, it is obvious that the content disclosed in the prior art, such as a specific method for removing autocorrelation, can also be applied to the present invention.

[0053] FIG. 2 is a flowchart of an interference removal method for a 5G ICS repeater according to an embodiment of the present invention.

[0054] Hereinafter, the above method will be exemplified and described as being performed by the interference removal device 1000 of the 5G ICS repeater shown in FIG. 1.

[0055] In step S2100, the interference removal device 1000 of the 5G ICS repeater acquires a first original signal. Specifically, the interference removal device 1000 of the 5G ICS repeater can acquire the first original signal by using the receiving antenna 4100 of the 5G ICS repeater.

[0056] In one embodiment, the original signal may include a signal transmitted from a transmission end at a base station or the like and a feedback signal in which the signal transmitted from the transmission antenna of the 5G ICS repeater is received again by the reception antenna 4100 of the 5G ICS repeater.

[0057] In step S2200, the interference cancellation device 1000 of the 5G ICS repeater can obtain a first error signal with interference removed by removing the first predicted feedback signal from the first original signal.

[0058] In step S2300, the interference cancellation device 1000 of the 5G ICS repeater can generate a first delayed signal in which the first error signal is delayed.

[0059] In one embodiment, the interference cancellation device 1000 of the 5G ICS repeater can generate an error signal by delaying the error signal by a preset time.

[0060] In one embodiment, the preset time can be set to vary depending on the specifications of the 5G ICS repeater, its application (such as the frequency of the signal to be relayed), the delay, the user, and so on.

[0061] In step S2400, the interference cancellation device 1000 of the 5G ICS repeater can determine whether the first original signal is a no signal based on the amplitude information of the first error signal.

[0062] In one embodiment, the interference cancellation device 1000 of the 5G ICS repeater can obtain the amplitude information of the first error signal and determine whether the first original signal is a no signal based on the obtained amplitude information of the first error signal.

[0063] In one embodiment, the amplitude information can include the amplitude size of the error signal and so on.

[0064] In one embodiment, the interference cancellation device 1000 of the 5G ICS repeater can obtain the amplitude information of the error signal through envelope detection of the error signal or the delay signal.

[0065] In one embodiment, when the amplitude information of the error signal of the interference cancellation device 1000 of the 5G ICS repeater is less than a preset reference amplitude size, it can be determined that the original signal is a no-signal.

[0066] In one embodiment, when the amplitude information of the error signal of the interference cancellation device 1000 of the 5G ICS repeater is greater than a preset reference amplitude size, it can be determined that the original signal is not a no-signal.

[0067] In step S2500, when it is determined that the first original signal is not a no-signal, the interference cancellation device 1000 of the 5G ICS repeater can generate a first narrowband removal signal by removing the characteristics of the narrowband signal from the first delay signal.

[0068] In step S2600, the interference cancellation device 1000 of the 5G ICS repeater can determine the first reference signal based on the determination result of whether the first original signal is a no-signal.

[0069] In one embodiment, when it is determined that the original signal is a no-signal, the interference cancellation device 1000 of the 5G ICS repeater can select the delay signal as the reference signal.

[0070] In one embodiment, when it is determined that the original signal is not a no-signal, the interference cancellation device 1000 of the 5G ICS repeater can select the narrowband removal signal as the reference signal.

[0071] In step S2700, the interference cancellation device 1000 of the 5G ICS repeater can generate a second predicted feedback signal based on the first reference signal.

[0072] In one embodiment, the interference cancellation device 1000 of the 5G ICS repeater can calculate a first interference signal prediction coefficient based on the correlation between a first error signal and a first reference signal, and perform a convolution operation between the first delayed signal and the first interference signal prediction coefficient to generate a new predicted feedback signal (first predicted feedback signal).

[0073] After that, the interference cancellation device 1000 of the 5G ICS repeater can repeat steps S2100 to S2700, such as generating a second error signal by removing the second predicted feedback signal from the second original signal received after the first original signal.

[0074] Also, in FIG. 2, step S2400 and step S2300 can be performed simultaneously or one can precede the other.

[0075] FIG. 3 is a flowchart of an interference cancellation method for a 5G ICS repeater according to another embodiment of the present invention.

[0076] Hereinafter, the above method will be exemplified and described as being performed by the interference cancellation device 1000 of the 5G ICS repeater shown in FIG. 1.

[0077] Steps S3100 to S3300 are substantially the same as steps S2100 to S2300 in FIG. 2, so the description thereof will be omitted.

[0078] In step S3400, the interference cancellation device 1000 of the 5G ICS repeater can generate a first narrowband removal signal by removing the characteristics of the narrowband signal from the first delayed signal.

[0079] In step S3500, the interference cancellation device 1000 of the 5G ICS repeater can determine whether the first original signal is a no signal based on the amplitude information of the first error signal. Based on the determination result of whether the first original signal is a no signal, the interference cancellation device 1000 of the 5G ICS repeater can determine either the first error signal or the first delay signal as the first reference signal.

[0080] In one embodiment, the amplitude information can include the magnitude of the amplitude of the error signal and the like.

[0081] In one embodiment, the interference cancellation device 1000 of the 5G ICS repeater can obtain the amplitude information of the error signal through envelope detection of the error signal or the delay signal.

[0082] In one embodiment, when the amplitude information of the error signal of the interference cancellation device 1000 of the 5G ICS repeater is less than a preset reference amplitude size, it can be determined that the original signal is a no signal.

[0083] In one embodiment, when the amplitude information of the error signal of the interference cancellation device 1000 of the 5G ICS repeater is greater than a preset reference amplitude size, it can be determined that the original signal is not a no signal.

[0084] In one embodiment, when it is determined that the original signal is a no signal, the interference cancellation device 1000 of the 5G ICS repeater can select the delay signal as the reference signal.

[0085] In one embodiment, when it is determined that the original signal is not a no signal, the interference cancellation device 1000 of the 5G ICS repeater can select the narrowband cancellation signal as the reference signal.

[0086] Since step S3600 is substantially the same as step S2700 in FIG. 2, the detailed description thereof is omitted.

[0087] After that, the interference cancellation device 1000 of the 5G ICS repeater can repeatedly perform steps S3100 to S3600, such as generating a second error signal by removing the second predicted feedback signal from the second original signal received after the first original signal.

[0088] FIG. 4 is a diagram showing an example of a 5G ICS repeater to which an interference cancellation device of a 5G ICS repeater according to an embodiment of the present invention is applied.

[0089] Referring to FIG. 4, the 5G ICS repeater can obtain a first original signal d(n) including a base station signal S(n), which is a signal radiated from a base station, and a feedback signal y(n), which is a signal radiated from a transmission antenna 4200, using a reception antenna 4100.

[0090] The 5G ICS repeater can generate a first error signal e(n) by removing the first predicted feedback signal y(n) from the first original signal d(n).

[0091] The 5G ICS repeater can generate a first delayed signal x(n) by delaying the first error signal e(n) by a preset time.

[0092] The 5G ICS repeater can generate a first narrowband removal signal by removing the narrowband characteristics included in the first delayed signal x(n).

[0093] The 5G ICS repeater can determine whether the original signal is a no-signal by performing envelope detection on the first delayed signal x(n).

[0094] When it is determined that the first original signal d(n) is a no-signal, the 5G ICS repeater can select the first delayed signal x(n) as the first reference signal. Also, when it is determined that the first original signal d(n) is not a no-signal, the 5G ICS repeater can select the first narrowband removal signal as the first reference signal.

[0095] When the first reference signal is selected, the 5G ICS repeater can calculate a first interference signal prediction coefficient w(n) based on the correlation between the first error signal e(n) and the first reference signal.

[0096] The 5G ICS repeater can generate a second predicted feedback signal by performing a convolution operation on the first delayed signal x(n) and the first interference signal prediction coefficient w(n).

[0097] Again, the 5G ICS repeater can generate a second error signal by removing the second predicted feedback signal from the second original signal.

[0098] At this time, the 5G ICS repeater can amplify the first error signal, the second error signal, etc. via the amplifier 1000 and radiate them via the transmission antenna 4200.

[0099] Also, after generating the first narrowband rejection signal, the 5G ICS repeater can select whether to generate the first narrowband rejection signal according to the determination result of whether the first original signal d(n) is a no-signal, without selecting either the first delayed signal x(n) or the first narrowband rejection signal as the first reference signal according to the determination result of whether the first original signal d(n) is a no-signal. Specifically, when it is determined that the first original signal d(n) is a no-signal, the 5G ICS repeater selects the first delayed signal x(n) as the first reference signal without generating the first narrowband rejection signal; when it is determined that the first original signal d(n) is not a no-signal, the 5G ICS repeater can generate the first narrowband rejection signal and select the first narrowband rejection signal as the first reference signal.

[0100] As described above, the embodiments of the present invention have been described as specific embodiments, but this is merely illustrative and the present invention is not limited thereto. It should be construed as having the broadest scope in accordance with the basic idea disclosed in this specification. Those skilled in the art can combine / substitute the disclosed embodiments to implement patterns of shapes not shown, but this will not deviate from the scope of the present invention. Furthermore, those skilled in the art can easily change or modify the disclosed embodiments based on this specification, and it is obvious that such changes or modifications also belong to the scope of the rights of the present invention.

Explanation of Signs

[0101] 1000: Interference cancellation device for 5G ICS repeater 1100: Subtractor 1200: Time delay unit 1300: Auto-correlation eliminator 1400: Reference signal determination unit 1500: Prediction feedback signal generation unit

Claims

1. In the interference removal method performed by the 5G ICS repeater, obtaining a first error signal by removing the first predicted feedback signal from a first original signal received via a receiving antenna; delaying the first error signal to generate a first delayed signal; determining whether the first original signal is a null signal based on amplitude information of the first error signal; determining a first reference signal based on the first delayed signal in response to a result of determining that the first original signal is absent; and generating a second predicted feedback signal based on the first reference signal; Including, Interference cancellation method for 5G ICS repeater.

2. generating a second error signal by removing the second predicted feedback signal from a second original signal received via the receiving antenna; The interference cancellation method for a 5G ICS repeater according to claim 1.

3. The step of determining a first reference signal comprises: If it is determined that the first original signal is no signal, selecting the first delayed signal as the first reference signal; The interference cancellation method for a 5G ICS repeater according to claim 1.

4. The step of determining a first reference signal comprises: if it is determined that the first original signal is not a no-signal, removing a characteristic of a narrowband signal from the first delayed signal to generate a first narrowband reject signal, and selecting the first narrowband reject signal as the first reference signal; The interference cancellation method for a 5G ICS repeater according to claim 1.

5. The step of determining whether the first original signal is a no signal includes: obtaining the amplitude information via envelope detection of the first error signal or the first delayed signal; and determining that the first original signal is a non-signal when the amplitude information is less than a preset reference amplitude size, or determining that the first original signal is not a non-signal when the amplitude information is equal to or greater than a preset reference amplitude size. The interference cancellation method for a 5G ICS repeater according to claim 1.

6. The preset reference amplitude size is: The 5G ICS repeater is set based on a result of measuring the first original signal when no signal is input to the 5G ICS repeater. The interference cancellation method for a 5G ICS repeater according to claim 5.

7. The step of generating the second predicted feedback signal comprises: calculating a first interference signal prediction coefficient based on a correlation between the first error signal and the first reference signal; and performing a convolution operation between the first delayed signal and the first interference signal prediction coefficients to generate the second predicted return signal. The interference cancellation method for a 5G ICS repeater according to claim 1.

8. In the interference removal method performed by the 5G ICS repeater, obtaining a first error signal by removing the first predicted feedback signal from a first original signal received via a receiving antenna; delaying the first error signal to generate a first delayed signal; removing a characteristic of a narrowband signal from the first delayed signal to generate a first narrowband removed signal; determining whether the first original signal is a null signal based on amplitude information of the first error signal; determining, according to a result of the absence of a signal of the first original signal, either the first delayed signal or the first narrow band rejection signal as a first reference signal; and generating a second predicted feedback signal based on the first reference signal; An interference cancellation method for a 5G ICS repeater, comprising:

9. a time delay unit that generates a first delayed signal by delaying a first error signal obtained by removing the first predicted feedback signal from a first original signal received via a receiving antenna; a reference signal determination unit that determines whether the first original signal is a non-signal based on amplitude information of the first error signal, and determines a first reference signal based on the first delayed signal in accordance with a result of the determination; and a predicted feedback signal generator for generating a second predicted feedback signal based on the first reference signal; An interference cancellation device for a 5G ICS repeater, comprising:

10. a subtractor for subtracting the second predicted feedback signal from a second original signal received via the receiving antenna to generate a second error signal. The interference cancellation device of a 5G ICS repeater according to claim 9.

11. The reference signal determination unit a reference signal selection unit that selects the first delayed signal as the first reference signal when the first original signal is determined to be a non-signal; The interference cancellation device of a 5G ICS repeater according to claim 9.

12. an autocorrelation remover for removing a characteristic of a narrowband signal from the first delayed signal to generate a first narrowband removed signal when it is determined that the first original signal is not a null signal; The reference signal determination unit a reference signal selection unit that selects the first narrow band rejection signal as the first reference signal; The interference cancellation device of a 5G ICS repeater according to claim 9.

13. The reference signal determination unit an amplitude information generator that obtains the amplitude information through envelope detection of the first error signal or the first delayed signal; and a reference signal selection unit that determines that the first original signal is a non-signal when the amplitude information is less than a preset reference amplitude size, or determines that the first original signal is not a non-signal when the amplitude information is equal to or greater than a preset reference amplitude size, The interference cancellation device of a 5G ICS repeater according to claim 9.

14. The preset reference amplitude size is: The 5G ICS repeater is set based on a result of measuring the first original signal when no signal is input to the 5G ICS repeater. The interference cancellation device of a 5G ICS repeater according to claim 13.

15. The predicted feedback signal generator a coefficient generator for calculating first interference signal prediction coefficients based on a correlation between the first error signal and the first reference signal; and an FIR filter that performs a convolution operation of the first delayed signal and the first interference signal prediction coefficient to generate the second predicted feedback signal; The interference cancellation device of a 5G ICS repeater according to claim 9.

16. a time delay unit that generates a first delayed signal by delaying a first error signal obtained by removing the first predicted feedback signal from a first original signal received via a receiving antenna; an autocorrelation remover for removing characteristics of a narrowband signal from the first delayed signal to generate a first narrowband removed signal; a reference signal selection unit that determines whether the first original signal is a non-signal based on amplitude information of the first error signal, and selects either the first delayed signal or the first narrow band rejection signal as a first reference signal according to a result of the determination; and and a predicted feedback signal generator configured to generate a second predicted feedback signal based on the first reference signal.

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