JP6653531B2 - Interference wave canceller - Google Patents

Description

  The present invention relates to a receiving device in a wireless communication system, and more particularly to an interference wave removing device for removing an interference wave signal included in a signal received by the receiving device.

In a conventional wireless communication system, a signal of another system becomes an interference wave signal with respect to a desired signal, and the communication environment may be deteriorated.
FIG. 2 is a block diagram for explaining a conventional interference wave removing apparatus.
In FIG. 2, the interference wave removing device 20 includes band pass filters 21 and 22, a delay unit 13, an interference wave detecting unit 14, an interference wave replica generating unit 15, and an interference wave removing unit 16.
FIG. 3 is a diagram illustrating a plurality of continuous interference waves in the frequency direction generated from one interference source. FIG. 4 is a diagram showing a frequency and a pass band of a conventional band-pass filter. FIG. 5 is a diagram illustrating a conventional band-pass filter that may cause erroneous detection of an interference wave and the position of the interference wave. FIG. 6 is a diagram showing that a part of the communication band is not passed by the band-pass filter.

The interference wave may be a case where a plurality of interference waves continue in the frequency direction from one interference source as shown in FIG. 3 or a case where the interference wave is a single interference wave.
When receiving the interference wave as shown in FIG. 3, the interference wave elimination device removes the interference wave in the band-pass filter 21 so as to cover the band (communication band) in which the base station and the communication terminal communicate as shown in FIG. Remove.
The conventional interference wave elimination device 20 has no problem when there is one interference wave in the band-pass filter 21 as shown in FIG. 4, but is connected to the communication band and the band-pass filter 11 on the frequency axis as shown in FIG. When there are two interference waves, the interference wave detection unit 14 may erroneously detect the interference wave due to the influence of the received interference wave A slightly.
If an interference wave is erroneously detected, a correct interference wave replica signal cannot be generated, and the interference wave removal performance may be degraded.
When the band-pass filter 21 is configured as shown in FIG. 6 so as not to receive the interference wave A, the band-pass filter 21 does not pass a part of the communication band, so that the communication quality deteriorates.

  As a prior art document, for example, Patent Document 1 discloses an invention that can cancel the influence of FFT window position shift with high accuracy even in an environment where mixing of analog waves and multipaths is unavoidable when canceling a looping wave. Have been.

JP 2009-272767 A

As shown in FIG. 5, when there are two interfering waves continuous on the frequency axis in the communication band and the bandpass filter 21, the interfering wave detector 14 causes the interfering wave There is a problem that a signal detection error may occur, and the interference wave removal performance is deteriorated.
An object of the present invention is to improve interference wave removal performance by improving the interference wave detection accuracy.

  An interference wave removing apparatus according to the present invention includes two interference wave removing bandpass filters, two interference wave detecting bandpass filters, a delay unit, an interference wave removing unit, an interference wave detecting unit, and an interference wave replica generating unit. The first interference wave removal bandpass filter passes a reception signal in a predetermined band, the delay unit delays the signal output from the first interference wave removal bandpass filter for a predetermined time, and outputs an interference wave detection unit. Detects an interference wave from a received signal passed through a predetermined band by a first interference wave detection band-pass filter and a reference signal passed through a predetermined band by a second interference wave detection band-pass filter. The generation unit generates an interference wave replica from the reference signal passed through a predetermined band by the second interference wave removal band-pass filter and the interference wave detection information output from the interference wave detection unit, and Wave removal unit and removing the interference wave by using the interference wave replica generated by the interference wave replica generation unit from the signal output from the delay unit.

  Further, the interference wave removing apparatus of the present invention includes two interference wave removing band-pass filters, an interference wave detecting band-pass filter, a delay unit, an interference wave removing unit, an interference wave detecting unit, and an interference wave replica generating unit. The first interference wave removal bandpass filter passes a reception signal in a predetermined band, the delay unit delays the signal output from the first interference wave removal bandpass filter for a predetermined time, and outputs an interference wave detection unit. Detects an interference wave from the received signal passed through the predetermined band by the first bandpass filter for interference wave removal and the reference signal passed through the predetermined band by the bandpass filter for interference wave detection, and the interference wave replica generation unit An interference wave replica is generated from a reference signal passed through a predetermined band by a second interference wave removal band-pass filter and interference wave detection information output from the interference wave detection unit, And removing the interference wave by using the interference wave replica generated by the interference wave replica generating unit from a signal output from the delay unit.

  Furthermore, an interference wave removing apparatus according to the present invention is the above-described interference wave removing apparatus, wherein the first and second interference wave detecting band-pass filters set a pass band in accordance with the interference wave. .

  ADVANTAGE OF THE INVENTION According to this invention, the removal performance of an interference wave can be improved by improving the detection accuracy of an interference wave.

FIG. 2 is a block diagram illustrating an interference wave removing apparatus according to an embodiment of the present invention. FIG. 10 is a block diagram for explaining a conventional interference wave removing device. FIG. 3 is a diagram illustrating a plurality of continuous interference waves in a frequency direction generated from one interference source. FIG. 7 is a diagram illustrating a frequency and a pass band of a conventional bandpass filter. It is a figure which shows the position of the conventional band pass filter and the interference wave which may make the detection of the interference wave erroneous. It is a figure showing that a part of a communication band is not passed by a band pass filter. It is a figure showing setting of a frequency and a band of each band pass filter of an interference wave elimination device concerning one example of the present invention. FIG. 6 is a diagram illustrating settings of an interference wave removing bandpass filter. FIG. 6 is a diagram showing that an interference wave removing bandpass filter receives a plurality of continuous interference waves on a frequency axis. FIG. 4 is a diagram showing settings of an interference wave detection bandpass filter. FIG. 8 is a diagram illustrating settings of an interference wave detection bandpass filter when receiving a plurality of interference waves having a communication band on a frequency axis. It is a figure showing that the frequency and the band which were different for the bandpass filter for interference wave detection of the reception signal and the reference signal of the interference wave elimination device concerning one example of the present invention were set up. FIG. 6 is a block diagram illustrating an interference wave removing apparatus according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram for explaining an interference wave removing apparatus according to one embodiment of the present invention.
In FIG. 1, an interference wave removing device 10 includes bandpass filters 11 and 17 for removing interference waves, bandpass filters 12 and 18 for detecting interference waves, a delay unit 13, an interference wave detection unit 14, an interference wave replica generation unit 15, An interference wave removing unit 16 is provided.

  In FIG. 1, an interference wave removing apparatus 10 receives a received signal, removes an interference wave outside the band of the received signal by an interference wave removing band-pass filter 11, and converts the received signal from which the interference wave has been removed into a delay unit 13. A predetermined time is delayed according to the interference wave replica output from the interference wave replica generation unit 15, and the interference wave removal unit 16 removes the interference wave based on the interference wave replica output from the interference wave replica generation unit 15, It is output as a signal after interference wave removal.

The interference wave detector 14 detects an interference wave from the received signal passed through the predetermined band by the interference wave detection band-pass filter 12 and the reference signal passed through the predetermined band by the interference wave detection band-pass filter 18. Then, the signal is output to the interference wave replica generation unit 15.
The interference wave replica generation unit 15 generates an interference wave replica signal from the signal output from the interference wave detection unit 14 and a reference signal passed through a predetermined band by the interference wave removal band-pass filter 17 to remove the interference wave. Output to the unit 16.
Note that the reference signal is a signal having only an ideal interference wave component included in the received signal. As a reference signal, if it is a known signal, it is generated and input by a signal generator previously installed in or outside the device, or input via a receiving device dedicated to the reference signal. The interference wave replica signal is a signal that can cancel the interference wave signal.

The bandpass filters 11 and 17 for removing the interference wave and the bandpass filters 12 and 18 for detecting the interference wave improve the detection accuracy of the interference wave.
First, the frequencies and bands of the interference wave removal bandpass filters 11 and 17 and the interference wave detection bandpass filters 12 and 18 are set according to the communication band and the position of the interference wave that interferes with the communication band.

FIG. 8 is a diagram showing the setting of the bandpass filter for removing interference waves.
As shown in FIG. 8, the bandpass filters 11 and 17 for removing the interference wave set the frequency and the band so as to cover the communication band in order to remove the interference wave in the communication band.
FIG. 9 is a diagram showing that the interference wave removing bandpass filter receives a plurality of continuous interference waves on the frequency axis.
The interference wave removing bandpass filters 11 and 17 may receive a plurality of interference waves connected on the frequency axis as shown in FIG.

FIG. 10 is a diagram showing the setting of the bandpass filter for interference wave detection.
The interference wave detection band-pass filters 12 and 18 set the frequency and the band so as to detect one interference wave in order to correctly detect the interference wave as shown in FIG.
In FIG. 10, there are interference waves A, B and C, but it is better to set the frequency and band of the interference wave detection band-pass filter 2 so as to pass the interference wave B which interferes with the communication band.
FIG. 11 is a diagram showing the setting of an interference wave detection band-pass filter when receiving a plurality of interference waves having a communication band on the frequency axis.
In FIG. 11, there are an interference wave A, an interference wave B, and an interference wave C. The interference waves that interfere with the communication band are the interference wave A and the interference wave B, and the frequency of the interference wave detection band-pass filters 12 and 18 is set so that the interference wave B that interferes with the communication band is passed. It is better to set the band.

FIG. 12 is a diagram showing that the bandpass filter for detecting the interference wave of the reception signal and the reference signal of the interference wave elimination device according to the embodiment of the present invention has set different frequencies and bands.
As shown in FIG. 12, when there is a frequency deviation between an interference wave included in a received signal and an interference component of a reference signal, the bandpass filter 12 for detecting an interference wave of the received signal is used to improve the detection accuracy of the interference wave. The frequency and band of the interference signal detection band-pass filter 18 of the reference signal may be different.
Further, in order to improve the interference wave removal performance, the frequency and band of the interference signal removal band-pass filter 11 for the received signal and the reference signal interference wave removal band-pass filter 17 may be different.

FIG. 13 is a block diagram for explaining an interference wave removing apparatus according to another embodiment of the present invention.
In FIG. 13, the interference wave removing device 30 includes interference wave removing bandpass filters 11 and 17, an interference wave detecting bandpass filter 18, a delay unit 13, an interference wave detecting unit 14, an interference wave replica generating unit 15, an interference wave It comprises a removing unit 16.

  In FIG. 13, an interference wave removing device 30 receives a received signal, removes an interference wave outside the band of the received signal by an interference wave removing bandpass filter 11, and converts the received signal from which the interference wave has been removed into a delay unit 13. A predetermined time is delayed according to the interference wave replica output from the interference wave replica generation unit 15, and the interference wave removal unit 16 removes the interference wave based on the interference wave replica output from the interference wave replica generation unit 15, It is output as a signal after interference wave removal.

The interference wave detector 14 detects an interference wave from the received signal passed through the predetermined band by the interference wave removal band-pass filter 11 and the reference signal passed through the predetermined band by the interference wave detection band-pass filter 18. Then, the signal is output to the interference wave replica generation unit 15.
The interference wave replica generation unit 15 generates an interference wave replica from the signal output from the interference wave detection unit 14 and a reference signal passed through a predetermined band by the interference wave removal band-pass filter 17, and 16 is output.

  In the embodiment of the present invention, the interference wave canceller 10 in FIG. 1 is the most preferable configuration. However, in order to reduce the circuit scale in the interference wave remover, as shown in FIG. Even if the signal of the interference wave removing band-pass filter 11 is input to the interference wave detecting section 14 without using the interference wave 12, the detection accuracy of the interference wave is improved by the conventional interference wave removing device 20, and the interference wave removing performance is improved. Can be improved.

  The interference wave elimination device according to the embodiment of the present invention can improve the detection accuracy of the interference wave and improve the interference wave elimination performance.

  Although the present invention has been described in detail above, the present invention is not limited to the interference wave canceling device described herein, and can be implemented with various modifications without departing from the spirit of the present invention.

  The present invention can be applied to a receiver for receiving an electric wave in an environment in which a plurality of interference waves are continuous in a frequency direction.

  10, 20, 30: interference wave canceller, 11, 17: bandpass filter for interference wave removal, 12, 18: bandpass filter for interference wave detection, 13: delay unit, 14: interference wave detection unit, 15: interference Wave replica generator, 16: interference wave remover, 21, 22: bandpass filter.

Claims (2)

It has two bandpass filters for removing interference waves, two bandpass filters for detecting interference waves, a delay unit, an interference wave removal unit, an interference wave detection unit, and an interference wave replica generation unit,
The first interference wave removal band-pass filter removes an interference wave outside a band of the input reception signal and passes a reception signal of a predetermined band,
The second interference wave removal band-pass filter sets the same frequency and band as the first interference wave removal band-pass filter for the input reference signal, and passes the reference signal,
First interference wave detection bandpass filter, interference is most frequently interference overlap on the frequency to the communication band of the first received signal of a predetermined band passed by the interference wave removal bandpass filter Set the frequency and band to pass one of the waves and pass the input received signal,
The second interference wave detection band-pass filter sets the same frequency and band as the first interference wave detection band-pass filter with respect to the input reference signal, and passes the reference signal.
The delay unit delays the signal output from the first interference wave removal band-pass filter in accordance with the interference wave replica output from the interference wave replica generation unit for a predetermined time,
The interference wave detection unit detects an interference wave from a signal that has passed through the first interference wave detection band-pass filter and the second interference wave detection band-pass filter,
The interference wave replica generation unit generates an interference wave replica from the signal that has passed through the second interference wave removal band-pass filter and the interference wave detection information output from the interference wave detection unit,
The interference wave removing device, wherein the interference wave removing unit removes the interference wave from the signal output from the delay unit using the interference wave replica generated by the interference wave replica generating unit. It has two interference wave removal bandpass filters, an interference wave detection bandpass filter, a delay unit, an interference wave removal unit, an interference wave detection unit, and an interference wave replica generation unit,
The first interference wave removal band-pass filter removes an interference wave outside a band of the input reception signal and passes a reception signal of a predetermined band,
The second interference wave removal band-pass filter sets the same frequency and band as the first interference wave removal band-pass filter for the input reference signal, and passes the reference signal,
The interference wave detection band-pass filter overlaps the input reference signal with the communication band of the reception signal of the predetermined band which has passed through the first interference wave elimination band-pass filter in frequency. Pass the reference signal by setting the frequency and band so as to pass one of the interfering interference waves,
The delay unit delays the signal output from the first interference wave removal band-pass filter by a predetermined time according to the interference wave replica output from the interference wave replica generation unit,
The interference wave detection unit detects an interference wave from a signal that has passed through the first interference wave removal band-pass filter and the interference wave detection band-pass filter,
The interference wave replica generation unit generates an interference wave replica from the signal that has passed through the second interference wave removal band-pass filter and the interference wave detection information output from the interference wave detection unit,
The interference wave elimination device, wherein the interference wave elimination unit removes an interference wave from a signal output from the delay unit using an interference wave replica generated by the interference wave replica generation unit.

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