KR200407860Y1 - Unwanted Interference Signal Detection and Cancellation System - Google Patents

Abstract

The present invention relates to a device for detecting and removing unwanted interference signals in a wireless communication system. When the desired and unwanted interference signals exist at the same time, the present invention detects and removes unwanted interference signals so that they are not input to the receiver. The purpose.

To this end, the present invention includes an input signal divider, a first adaptive signal detector, a second adaptive signal detector, an offset signal combiner, a reference error signal detector, a residual signal combiner output, an interference signal detector, and an interference signal comparison output. do.

According to the present invention, it is possible to detect and remove the direct feedback signal directly fed back from the transmitting antenna to the receiving antenna, thereby preventing the oscillation of the receiver caused by the direct feedback signal, and the input / output signal of the wireless repeater system. By improving the separation to increase the output of the system, there is an effect that can extend the service area of the wireless repeater system, improve the quality of service and the stability of the system.

The present invention can detect and remove unwanted interference signals when a desired signal and an unwanted interference signal exist at the same time, and also detect and remove a single constant signal when a plurality of signals exist. As a basic technology that can be applied, there is an effect that can be widely applied to a wireless communication system and various other communication systems.

Wireless communication, wireless repeater, interference signal, direct feedback signal, interference noise, signal combiner

Description

Unwanted Interference Signal Detection and Cancellation System

1 is a basic configuration of the apparatus for detecting and removing unwanted interference signals according to the present invention.

FIG. 2 is a detailed configuration diagram of the first adaptive signal detector of FIG. 1. FIG.

FIG. 3 is a detailed configuration diagram of the second adaptive signal detector of FIG. 1. FIG.

4 is a detailed configuration diagram of the residual signal coupling output of FIG.

5 is a detailed configuration diagram of another embodiment according to the present invention.

<Description of Symbols for Main Parts of Drawings>

100: input signal divider 102: first adaptive signal detector

104: second adaptive signal detector 106: offset signal combiner

108: reference error signal detector 110: residual signal combined output

112: interference signal detector 114: interference signal comparison output

200, 300: interference signal canceller 202, 302: cancel signal detector

400: first residual signal detector 402: second residual signal detector

404: residual signal comparison output 500: signal splitter

The present invention relates to a device for detecting and removing unwanted interference signals in a wireless communication system. When the desired and unwanted interference signals exist at the same time, the present invention detects and removes unwanted interference signals so that they are not input to the receiver. .

In general, a wireless communication system receives and amplifies a weak signal of desired size and radiates the amplified signal to a wireless space through a transmission antenna. Therefore, since the transmission signal in the wireless communication system is a signal having a much stronger magnitude than the desired reception signal, the transmission signal is fed back to the reception antenna and mixed with the desired reception signal and input to the receiver. This phenomenon, that is, when a desired signal and an unwanted interference signal are combined in a radio space and simultaneously input to a receiver (or a communication device), is a phenomenon generally occurring in wireless communication.

Since the transmission signal fed back to the receiving antenna inputs the interference noise which degrades the performance of the receiver and is a fundamental cause of oscillation, it detects that unwanted interference noise signal components fed back to the receiving antenna are not input to the receiver. It needs to be removed.

However, the feedback signal (interference signal) from which the signal transmitted through the transmitting antenna is fed back to the receiving antenna is continuously changed with time with amplitude, phase and delay time, so it is not easy to detect such feedback signal.

This phenomenon also occurs in a wireless relay device installed and operated for the purpose of providing a better mobile communication service by installing a weak signal output from a base station and amplifying the weak signal and outputting it to a mobile station. Done. When the signal transmitted through the transmitting antenna in the wireless relay device is fed back to the receiver to act as interference noise, the performance of the receiver is degraded and the oscillation does not operate the system smoothly.

That is, the wireless relay device includes a separate reception antenna and a separate transmission antenna in order to perform a function of receiving and amplifying a weak radio wave and then transmitting the amplified signal again. When the radio signal is relayed and transmitted at the same frequency through the radio relay device, the strong transmission signal is fed back to the reception antenna and input together with the desired reception signal through the reception antenna. It is a cause of weakening function.

Therefore, in the radio relay apparatus, it is necessary to accurately detect and remove the unwanted interference signal combined with the desired signal before the desired signal is input to the receiver.

The present invention has been made to solve the above problems, and when the desired signal and the unwanted interference signal is present at the same time, the detection and removal of the interference signal that can not be input to the receiver by detecting and removing the unwanted interference signal The object is to provide a device.

Another object of the present invention is to transmit from a transmit antenna to a receive antenna among various interference noise signals (including direct feedback signals, multipath signals, radio channel interference signals, and other noise signals) input to receive antennas in various wireless communication systems. The present invention provides a device for detecting and removing a direct feedback signal inputted directly.

Another object of the present invention, in order to prevent oscillation caused by the return of the wireless transmission signal output from the transmitting antenna to the receiving antenna, it is changed in real time by the change of the external wireless communication environment conditions and feedback It is an object of the present invention to provide a real-time interference signal detection and removal device that can adapt to changes in amplitude, phase, and delay time of an interference signal in real time.

In order to achieve the above object, the present invention is a device for detecting and removing unwanted interference signal in a wireless communication system,

An input signal divider for combining a desired signal with various unwanted interference signals in an external wireless space and distributing a signal received through a receiving antenna system according to a predetermined ratio;

Inverse phase and same time delay with respect to the signal distributed in the input signal divider and the unwanted interference signal, in order to receive the divided signal uniformly distributed by the input signal divider and to remove the interference signal which is an unwanted signal component. A first adaptive signal detector combined with a reference signal having a first signal to remove a predetermined interference signal and detect only a desired signal component and other interference signals to generate a first cancellation signal and a first error signal;

In order to remove an interference signal that is an unwanted signal component by receiving the distribution signal uniformly distributed by the input signal divider, to remove a constant interference signal in combination with a reference signal and detect only the desired signal component and other interference signals A second adaptive signal detector for generating a second cancellation signal and a second error signal;

In order to receive the first cancellation signal detected by the first adaptive signal detector and to remove an interference signal that is an unwanted signal component, the cancellation signal component is combined with the second cancellation signal detected by the second adaptive signal detector. A cancellation signal combiner for detecting;

A reference error signal detector for detecting an error signal by comparing and comparing the offset signal detected by the offset signal combiner with a reference signal;

In order to receive a first cancellation signal and a first error signal detected by the first adaptive signal detector, and to detect a residual signal (a signal including a desired signal and other interference signals) that does not include an unwanted interference signal, A residual signal coupling output unit for combining the second offset signal and the second error signal detected by the second adaptive signal detector to detect, compare, and output the residual signal;

An interference signal that receives a distribution signal uniformly distributed by the input signal divider, and combines the residual signal detected, compared and output by the residual signal combining output unit to detect only unwanted interference signals among the signals received through the receiving antenna. Detectors; And

In order to detect the unwanted interference signal among the signals received through the receiving antenna by receiving the cancellation signal detected by the cancellation signal combiner, an output signal detected by the interference signal detector is mutually compared and analyzed in real time. An interference signal comparison output unit for outputting an interference signal;

Characterized in that it comprises a.

In addition, the present invention further includes a signal divider for distributing the first error signal generated by the first adaptive signal detector at a constant rate and sending the same to the second adaptive signal detector and the residual signal combiner, respectively, and input through a receiving antenna. It is characterized by detecting and outputting only the unwanted interference signal and other residual signals not including the unwanted interference signal.

In addition, the first adaptive signal detector of the present invention includes an interference signal canceller and an offset signal detector, and uses a reference signal to detect an unwanted interference signal among signals input through a receiving antenna. A first error signal obtained by subtracting the same signal as the reference signal is generated, and a first cancellation signal identical to the reference signal is generated.

In addition, the second adaptive signal detector of the present invention comprises an interference signal canceller and a cancellation signal detector, the difference signal between the reference signal and the cancellation signal in order to detect the unwanted interference signal from the signal input through the receiving antenna The second error signal is generated by subtracting the same signal as the reference error signal among the input signals using the generated reference error signal, and generates a second offset signal identical to the reference error signal.

In addition, the second adaptive signal detector of the present invention uses a signal distributed from a signal divider by using a first error signal output from the first adaptive signal detector as an input signal to cancel the second offset signal and the second error signal. It characterized in that to generate.

In addition, the present invention uses a reference signal for the first adaptive signal detector to detect the first cancellation signal, and a reference error generated by a reference error signal detector for the second adaptive signal detector to detect the second cancellation signal. It is characterized by using a signal.

The reference error signal detector of the present invention compares a reference error signal input to generate the second offset signal and the second error signal with a reference signal and an offset signal output from the offset signal combiner in real time. It is characterized by outputting an error signal by analyzing.

In addition, the residual signal coupling output of the present invention, by subtracting the unwanted interference signal from the signal input through the receiving antenna using the first offset signal and the second offset signal, the first error signal and the second error signal. It is characterized by detecting only residual signals including desired signals and other interference signals.

In addition, the interference signal detector of the present invention is characterized by detecting the unwanted interference signal by using the residual signal including the desired signal and other interference signals subtracting the unwanted interference signal.

The present invention is a technology capable of detecting and removing unwanted interference signals before the input terminal of the receiver so that unwanted interference signals are not input to the receiver. In particular, the feedback interference noise signal generated from a wireless communication device using the same frequency, etc. The unwanted interference signal may be detected and eliminated before the input terminal of the receiver so that is not input to the receiver.

The present invention applies a technique for adaptively detecting and removing unwanted interference signals in real time before the unwanted interference signal components other than the desired signals are input to the receiver among the received signals received through the radio path in the wireless communication system. Device.

In addition, the present invention has the advantage of real-time adaptability that can be used for the detection and removal of interference signals input to the receiving end of various communication devices as well as wireless communication devices.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a basic configuration of an apparatus for detecting and removing unwanted interference signals according to the present invention, FIG. 2 is a detailed configuration diagram of the first adaptive signal detector of FIG. 1, and FIG. 3 is a second adaptive signal detector of FIG. 1. 4 is a detailed configuration diagram of the residual signal coupling detector of FIG. 1, and FIG. 5 illustrates an embodiment according to the present invention.

First, as shown in FIG. 1, the apparatus for detecting and removing unwanted interference signals according to the present invention includes an input signal divider 100, a first adaptive signal detector 102, a second adaptive signal detector 104, and an offset signal. The combiner 106, the reference error signal detector 108, the residual signal coupling output 110, the interference signal detector 112, and the interference signal comparator 114 is configured.

In general, a signal input through a receiving antenna includes not only a desired signal but also a direct feedback signal, a multipath signal, a radio channel interference signal, and other noise signals. In the present invention, signals for detection and removal in the present invention are called interference signals and all other signals are called other signals.

The input signal splitter 100 performs a function of regularly dividing and distributing the received input signal in order to detect and remove unwanted interference signal components from various signals input to the receiving antenna.

The first adaptive signal detector 102 detects and removes unwanted interference signal components among the unwanted interference signals and other signals distributed by the input signal divider 100. Non-interfering signal components and other signal components and the reverse phase reference signal are combined to output a first cancellation signal and a first error signal.

The second adaptive signal detector 104 detects and removes unwanted interference signal components among the unwanted interference signals and other signals distributed by the input signal divider 100. Non-interference signal components and other signal components and the reference error signal output from the reference error signal detector 108 are combined to output a second cancellation signal and a second error signal.

The offset signal combiner 106 combines the first offset signal detected by the first adaptive signal detector 102 and the second offset signal detected by the second adaptive signal detector 104 to output an offset signal. The error signal detector 108 combines the reference signal and the cancellation signal output from the cancellation signal combiner 106 to output a reference error signal.

In addition, the residual signal coupling output 110 may include a first cancellation signal and a first error signal detected by the first adaptive signal detector 102 and a second cancellation signal detected by the second adaptive signal detector 104. And combine and compare the second error signal to output a residual signal.

The interference signal detector 112 combines the signal distributed by the input signal splitter 100 with the output signal (residual signal) detected by the residual signal coupling output 110, and thus inputs unwanted interference signals and other signals. An unwanted interference signal component is detected, and the interference signal comparator 114 compares the canceled signal generated by the cancellation signal combiner 106 with the unwanted interference signal detected by the interference signal detector 112 in real time. And outputting.

When the offset signal generated by the cancellation signal combiner 106 and the signal obtained by comparing the unwanted interference signal detected by the interference signal detector 112 in real time with the interference signal comparison output unit 114 coincide with each other, Since the output signal is only an unwanted interference signal, the output signal of the residual signal coupling output 110 may be input to the receiver.

The reference signal can be obtained variously according to the application field of the present invention. For example, in the wireless relay device, the transmission signal transmitted to the transmission antenna can be sampled at a constant rate. The reference signal sampled at a constant rate has a correlation with the direct feedback signal fed directly from the transmitting antenna to the receiving antenna. In addition, the direct feedback signal fed directly from the transmitting antenna to the receiving antenna is inevitably detected and removed because it is much larger than other interference signals (multipath signals, radio channel interference signals and other noise signals) and desired signals. do.

FIG. 2 is a detailed configuration diagram of the first adaptive signal detector 102 of FIG. 1 and includes an interference signal canceller 200 and a cancellation signal detector 202.

The interference signal canceller 200 generates a signal component obtained by subtracting the reference signal component of the reverse phase by combining the signal divided by the input signal divider 100 at a predetermined ratio with the reverse phase reference signal (hereinafter, referred to as a first error). The cancellation signal detector 202 is an inverse phase of a signal distributed by the input signal splitter 100 at a constant ratio and a first error signal that is a signal component generated by the interference signal canceller 200. The signals are combined to generate a first cancellation signal.

3 shows a detailed configuration diagram of the second adaptive signal detector 104 of FIG. 1 and includes an interference signal canceller 300 and a cancellation signal detector 302.

The interference signal canceller 300 combines the signal of the signal divided by the input signal divider 100 at a constant ratio with the reference error signal of the reverse phase of the reference error signal generated by the reference error signal detector 108, A signal component (hereinafter, referred to as a second error signal) in which the reference error signal component is subtracted is generated, and the cancellation signal detector 302 is a signal distributed by the input signal splitter 100 at a constant ratio and an interference signal canceller ( A second cancellation signal is generated by combining the inverse phase signal of the second error signal, which is a signal component generated at 300.

FIG. 4 is a detailed block diagram of the residual signal coupling output unit 110 of FIG. 1, and includes a first residual signal detector 400, a second residual signal detector 402, and a residual signal comparison output unit 404. It is configured by.

The first residual signal detector 400 reversely combines the first error signal generated by the first adaptive signal detector 102 and the second offset signal generated by the second adaptive signal detector 104 in reverse phase. Create In addition, the second residual signal detector 402 reversely combines the second error signal generated by the second adaptive signal detector 104 and the first cancellation signal generated by the first adaptive signal detector 102 in a reversed phase. Create The residual signal comparison output unit 404 compares and analyzes the residual signal generated by the first residual signal detector 400 and the residual signal generated by the second residual signal detector 402 in real time to output a residual signal.

FIG. 5 illustrates an embodiment according to the present invention, and includes an input signal splitter 100, a first adaptive signal detector 102, a second adaptive signal detector 104, a cancellation signal combiner 106, and a reference error. The signal detector 108, the residual signal coupling output unit 110, the interference signal detector 112, the interference signal comparison output unit 114, and the signal splitter 500 are configured to be included.

The signal splitter 500 distributes the first error signal generated by the first adaptive signal detector 102 at a constant ratio and transmits the first error signal to the second adaptive signal detector 104 and the residual signal coupling output 110, respectively. Do this.

In the present exemplary embodiment, the second adaptive signal detector 104 uses the signal distributed by the signal splitter 500 without using the signal distributed by the input signal divider 100 and uses the second canceled signal and the second cancel signal. An error signal is generated, and the residual signal coupling output unit 110 includes a first error signal, a first offset signal generated by the first adaptive signal detector 102, and a second adaptive signal distributed at a constant ratio in the signal splitter 500. The second error signal and the second cancellation signal generated by the signal detector 104 are used to generate a residual signal as an output signal.

The wireless communication system configured as described above may use a reference signal for a signal sampled at a constant ratio from a transmitting antenna, and have a correlation with the reference signal, that is, a direct feedback signal directly returned from the transmitting antenna to the receiving antenna in real time. It is possible to precisely detect the signal, and by subtracting the direct feedback signal detected from the input signal input through the receiving antenna, it is possible to detect a signal including only a desired signal and other interference signals and input it to the input terminal of the receiver.

In general, in the wireless communication system, the direct feedback signal directly returned from the transmitting antenna to the receiving antenna is a signal which is much larger than the desired signal and various other interference signals, and thus it is necessary to detect and remove the direct feedback signal. Since the cross-correlation with the reference signal sampled at a constant ratio in, it is possible to detect and remove the direct feedback signal by applying the above configuration.

According to the present invention, since only the desired signal component and other interference signals can be input to the receiver by detecting and removing the largest signal component among unwanted interference noises among the various signals combined in the wireless space and input to the receiving antenna. In addition, the oscillation phenomenon caused by the direct feedback signal can be fundamentally prevented, the output of the power amplifier can be improved, and the system efficiency can be improved.

In particular, the present invention is not only applicable to the base station system but also to the wireless repeater system for mobile communication and various general communication systems.

As described in detail above, according to the apparatus for detecting and removing unwanted interference signals according to the present invention, it is possible to detect a direct feedback signal fed back from a transmitting antenna to a receiving antenna in various wireless communication systems, and the detected direct feedback signal. Since the direct feedback signal having the largest interference signal component is removed from the input signals inputted to the receiving antenna by combining various signals, the oscillation phenomenon of the receiver generated by the direct feedback signal can be prevented. It works.

In addition, since it is possible to fundamentally eliminate the direct feedback signal commonly generated in the wireless repeater system, it is possible to increase the output of the wireless repeater system by improving the separation of input / output signals of the wireless repeater system, and thus the wireless repeater system. This service area and coverage can be expanded, and service quality and system performance can be improved.

In addition, the present invention is not only applicable to cellular, PCS system, IMT-2000 system and wireless communication system applying CDMA technology currently commercially available, but also an error signal that is an unwanted signal component generated in other general communication systems. There is an effect that can be widely applied to the detection and removal of.

In the above described a preferred embodiment of the present invention, the present invention is not limited to this and those skilled in the art will be able to various modifications and modifications within the scope without departing from the spirit of the present invention.

Claims (9)

In the device for detecting and removing unwanted interference signal in a wireless communication system, An input signal distributor 100 for combining a desired signal with various unwanted interference signals in an external wireless space and distributing a signal received through a receiving antenna system according to a predetermined ratio; In order to receive a distribution signal uniformly distributed by the input signal divider 100 and to remove an interference signal that is an unwanted signal component, the input signal divider 100 and the unwanted interference signal A first adaptive signal detector 102, combined with a reference signal having an inverse phase and equal time delay, removes a constant interference signal and detects only desired signal components and other interference signals to produce a first offset signal and a first error signal. ); In order to receive a distribution signal uniformly distributed by the input signal splitter 100, in order to remove an interference signal that is an unwanted signal component, in combination with a reference signal to remove a constant interference signal and the desired signal component and other interference signals A second adaptive signal detector 104 for detecting only and generating a second cancellation signal and a second error signal; A second cancel signal detected by the second adaptive signal detector 104 to receive the first cancel signal detected by the first adaptive signal detector 102 and to remove an interference signal that is an unwanted signal component; An offset signal combiner 106 that detects only an offset signal by combining; A reference error signal detector 108 which detects an error signal by comparing and analyzing the offset signal and the reference signal detected by the offset signal combiner 106; The first cancellation signal and the first error signal detected by the first adaptive signal detector 102 are input to detect residual signals (signals including desired and other interference signals) that do not include unwanted interference signals. In order to achieve this, the residual signal combining output unit 110 combines the second offset signal and the second error signal detected by the second adaptive signal detector 104 to detect, compare, and output the residual signal; Undesired interference among the signals received through the receiving antenna by receiving the distribution signal uniformly distributed by the input signal splitter 100, combines the residual signal detected, compared and output by the residual signal combiner output 110 An interference signal detector 112 for detecting only a signal; And The output signal detected by the interference signal detector 112 is detected in real time in order to receive an offset signal detected by the cancellation signal combiner 106 and detect only an unwanted interference signal among the signals received through the reception antenna. An interference signal comparison output unit 114 for comparing and analyzing each other and outputting unwanted interference signals; Apparatus for detecting and removing unwanted interference signals comprising a. The method of claim 1, The signal distributor 500 further distributes the first error signal generated by the first adaptive signal detector 102 at a constant rate and sends the first error signal to the second adaptive signal detector 104 and the residual signal coupling output 110, respectively. And detecting and outputting only unwanted interference signals and other residual signals not including unwanted interference signals among signals input through the receiving antenna. The method of claim 1, The first adaptive signal detector 102 includes an interference signal canceller 200 and an offset signal detector 202, and uses a reference signal to detect an unwanted interference signal from a signal input through a receiving antenna. And generating a first error signal obtained by subtracting a signal identical to the reference signal among the input signals, and generating a first cancellation signal identical to the reference signal. The method of claim 1, The second adaptive signal detector 104 includes an interference signal canceller 300 and a cancellation signal detector 302, and cancels a reference signal to detect an unwanted interference signal from a signal input through a receiving antenna. A second error signal obtained by subtracting the same signal as the reference error signal from the input signal using the reference error signal generated as a difference signal of the signal, and generating a second offset signal identical to the reference error signal Device for detecting and removing interference signals. The method of claim 1, The second adaptive signal detector 104 uses a signal distributed from the signal distributor 500 as an input signal by using a first error signal output from the first adaptive signal detector 102 and a second cancellation signal. And detecting the unwanted interference signal, wherein the second error signal is generated. The method of claim 1, A reference signal is used for the first adaptive signal detector 102 to detect the first cancellation signal, and a reference error signal detector 108 is used for the second adaptive signal detector 104 to detect the second cancellation signal. And an apparatus for detecting and removing unwanted interference signals, using the generated reference error signal. The method of claim 1, The reference error signal detector 108 compares the reference error signal input to generate the second offset signal and the second error signal with the reference signal and the offset signal output from the offset signal combiner 106 in real time. And analyzing and outputting an error signal. The method of claim 1, The residual signal coupling output unit 110 may use a first offset signal, a second offset signal, a first error signal, and a second error signal to subtract an unwanted interference signal from a signal input through a receiving antenna. Apparatus for detecting and removing unwanted interference signals, characterized in that only residual signals including signals and other interference signals are detected. The method of claim 1, The interference signal detector 112 detects and removes unwanted interference signals using residual signals including desired signals and other interference signals after subtracting unwanted interference signals. .

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