KR100941491B1 - System of echo cancellation and echo channel estimation using the multiple antennas - Google Patents

Abstract

The present invention discloses a system capable of relaying a transmission signal without interfering with the echo signal by removing the echo signal unnecessarily received by the relay device.

The echo signal cancellation and echo channel derivation system using the multi-antenna of the present invention is configured to relay transmission signals between the transmission apparatus and the reception apparatus through a relay apparatus configured with the reception antenna and the transmission array antenna, and transmits signals and echoes from the transmission apparatus. A reception antenna for receiving the echo signal through the channel, a vector generation module for generating the preprocessing vector and transmitting the received signal and the echo signal to the echo signal canceling module, and multiplying the preprocessing vector with the transmission signal and the echo signal and echo signal And a relay device including a transmission array antenna which receives a retransmission signal from the echo signal removal module and removes only the retransmission signal from the echo signal removal module.

Antenna, echo signal, echo channel, beamforming, spatial multiplexing, PN signal, pilot signal

Description

Echo cancellation and echo channel estimation system using multiple antennas {SYSTEM OF ECHO CANCELLATION AND ECHO CHANNEL ESTIMATION USING THE MULTIPLE ANTENNAS}

The present invention relates to a technique for relaying a transmission signal without interfering with the echo signal by removing the echo signal in relaying the transmission signal received from the transmitter to the receiver.

The relay system uses a relay to increase the communication distance and to increase the reception performance.

These relays are divided into AF (amplify-and-forward) method of amplifying and retransmitting the received transmission signal as it is, and DF (decode-and-forward) method of eliminating the effect of thermal noise by decoding the received transmission signal. .

However, the transmission signal received by the relay device is amplified and retransmitted to the transmission device, and at the same time, the reception antenna in the relay device receives an unnecessary echo signal. This echo signal interferes with the transmission signal to be retransmitted to the reception device. Cause.

Recently, as described above, research on an echo cancellation system (ICS) for removing an echo signal causing interference, that is, an interference cancellation system (ICS) has been actively conducted.

As shown in FIG. 1, the interference cancellation system includes a single-input single-output (SISO) structure and includes a source station (SS), a relay station (RS), and a destination station (DS).

Specifically, the interference signal removing process of the interference cancellation system is performed as follows. First, the receiving antenna of the RS receives a signal to be transmitted to the DS from the SS, and the transmitting antenna of the RS receives and amplifies the signal to be transmitted to the DS. Also resend to DS. At this time, the amplified or other processed transmission signal in the repeater is called a retransmission signal. In this process, the reception antenna of the RS receives the retransmission signal retransmitted by the transmission antenna of the RS to the DS through an echo channel, and this signal is called an echo signal. Therefore, the echo signal interferes with the transmission signal to be retransmitted to the DS received from the SS.

Accordingly, in order to reduce the influence of the echo signal transmitted to the reception antenna of the RS, the transmission antenna amplifies the transmission signal amplification strength to be retransmitted to the DS.

On the other hand, in order to remove the echo signal generated in spite of the limitation of the amplification strength, the receiving antenna of the RS is provided with a filter, which not only makes the receiving antenna of the RS very complicated, but also does not guarantee stable signal transmission and reception. That is, overflow may occur due to continued superposition and amplification of the echo signals remaining without being completely removed.

In order to solve the above problems, the present invention solves the amplification constraints of the repeater by eliminating echo signals by deriving the pre- and post-processing and spatial multiplexing of the transmit / receive array antenna structure and the echo channel. It also reduces system complexity and ensures stable signal transmission.

The echo signal cancellation and echo channel derivation system using multiple antennas proposed by the present invention for achieving the technical problem is configured to relay a transmission signal between a transmission device and a reception device through a relay device configured with a reception antenna and a transmission array antenna. ,

A reception antenna for receiving a transmission signal and an echo signal through an echo channel, a vector generation module for generating a preprocessing vector and applying it to the echo signal removal module together with the transmission signal and the echo signal received from the reception antenna; And a relay device including a echo signal removal module for removing only the echo signal by multiplying the vector, the transmission signal and the echo signal, and a transmission array antenna for receiving the retransmission signal from the echo signal removal module and retransmitting the signal to the receiver.

Meanwhile, the echo signal cancellation and echo channel derivation system using multiple antennas according to the second embodiment of the present invention is configured to relay transmission signals between the transmission device and the reception device through a relay device configured with a reception array antenna and a transmission antenna. ,

A vector array module for generating a post-processing vector and receiving the transmitted signal, the echo signal through the echo channel, and the echo signal canceling module together with the transmitted signal and the echo signal received from the receiving array antenna. And a echo signal removal module for removing only the echo signal by multiplying the post-processing vector by the transmission signal and the echo signal, and a relay device including a transmission antenna for receiving the retransmission signal from the echo signal removal module and retransmitting the signal to the receiver.

In addition, the echo signal cancellation and echo channel derivation system using multiple antennas according to the third embodiment of the present invention is configured to relay transmission signals between the transmission device and the reception device through a relay device configured with the reception antenna and the transmission array antenna. ,

A retransmission signal in which a transmission signal, a reception antenna for receiving an echo signal through an echo channel, and PN signals having orthogonality are generated, and one PN signal is added to the transmission signal, and the PN signal is added. And a PN signal generation module for applying the PN signal to the transmission array antenna and a transmission array antenna for receiving the retransmission signal including the PN signal from the PN signal generation module and transmitting the retransmission antenna to the receiving device.

According to the present invention as described above, it is possible to remove the echo signal through pre- and post-processing or echo channel derivation, and at the same time to relax the amplification rate constraints of the repeater through spatial multiplexing of the transmit and receive array antenna structure.

In addition, the complexity of the system can be reduced by simple pre- and post-processing vector generation, and stable signal transmission can be achieved without interference with the echo signal.

The features and advantages of the present invention will become more apparent from the detailed description for carrying out the invention according to the accompanying drawings. In the meantime, when it is determined that the detailed description of the known functions and configurations related to the present invention may unnecessarily obscure the subject matter of the present invention, it should be noted that the detailed description is omitted.

2 is a block diagram illustrating an echo signal cancellation and echo channel derivation system S using multiple antennas according to the present invention. In the present invention, the system includes a transmitter 100, a relay 200 and a receiver 300.

, 수신안테나가 수신하는 신호는

, 송신배열안테나를 써 재전송하는 신호는

, 그리고 수신장치가 수신하는 신호는

인 것으로 상정한다.In the following, it will be omitted, but the transmission signal of the transmission apparatus of the present invention

, The signal that the receiving antenna receives

Signal retransmitted using the transmit array antenna

And the signal that the receiver receives

Assume to be

The transmitting device 100 transmits a transmission signal to the relay device 200, and the relay device 200 retransmits the transmission signal received from the transmitting device to the receiving device 300 through the transmission array antenna, and the receiving device retransmits. Receive the signal.

The relay device 200 includes a receiving antenna 210, a vector generating module 220, an echo signal removing module 230, and a transmitting array antenna 240.

The reception antenna 210 receives the transmission signal and the echo signal through the echo channel from the transmitter and applies it to the vector generation module, and the vector generation module 220 generates the preprocessing vector to receive the transmission signal and the echo signal received from the reception antenna. To the echo signal cancellation module.

Here, the echo signal means a signal returned to the repeater receiving antenna as the repeater transmitting array antenna retransmits the transmitting signal to the receiving apparatus, and the echo channel is a path through which the echo signal is applied, and the repeater transmitting array antenna and the repeater receiving antenna It means channel between.

The echo signal removing module 230 multiplies the preprocessing vector received from the vector generating module by the transmission signal and the echo signal to suppress the generation of the echo signal and applies the retransmission signal to the transmission array antenna.

The transmission array antenna 240 receives the retransmission signal from the echo signal canceling module and amplifies the retransmission signal and retransmits it to the receiving apparatus. At this time, the retransmission signal according to the retransmission is echoed to the reception antenna of the repeater (echo signal) through the echo channel, and the reception apparatus 300 receives the retransmission signal.

개의 송신배열안테나(240)와 하나의 수신안테나(210)로 이루어진 중계장치(200)의 구조를 나타내고 있다. 여기서 에코채널은

개 송신배열안테나와, 수신안테나 사이의

벡터채널

로 나타낼 수 있다. 이때,

는

째 송신배열안테나로부터 수신안테나 사이의 채널이며, 상기 상술한 바를 정리하면 아래와 같은 신호모델인 [수학식 1]로 정의할 수 있다.Specifically, Figure 3 is attached to

The structure of the relay device 200 including two transmitting array antennas 240 and one receiving antenna 210 is shown. Where the echo channel is

Between the transmitting antenna and the receiving antenna

Vector channel

It can be represented as. At this time,

Is

It is a channel between the transmit array antenna and the receive antenna, and summed up above, it can be defined by the following signal model [Equation 1].

..................................... [수학식 1]

Equation 1

는

시간동안에 중계장치 열잡음을 나타낸다.

시간에 수신안 테나가 수신하는 신호

를 살펴보면, 송신장치로부터 인가받는 송신신호 외에 에코채널을 통해

이전 시간에 송신배열안테나로부터 전송된 재전송신호

가 에코채널

과 곱해져 반향신호로 수신됨을 알 수 있다.here,

Is

Indicates relay thermal noise during time.

Signal received by the receiving antenna at time

In addition, through the echo channel in addition to the transmission signal is received from the transmitter

Retransmission signal transmitted from transmit array antenna in previous time

Echo Channel

It can be seen that it is multiplied by and received as an echo signal.

시간에 수신장치(300)가 수신하는 신호는 아래의 [수학식 2]와 같이 나타낼 수 있다.Also,

The signal received by the receiving device 300 at time may be represented by Equation 2 below.

...................................[수학식 2]

Equation 2

는

시간에 수신장치의 열잡음을 나타낸다.At this time,

Is

Indicates the thermal noise of the receiver at time.

Referring to FIG. 4, first, the reception antenna 210 applies a transmission signal received from the transmission apparatus 100 and an echo signal through an echo channel to the vector generation module, and the vector generation module 220 transmits the transmission signal from the reception antenna. The echo channel is applied to estimate the echo channel, and a preprocessing vector is generated from the estimated echo channel through Equation 3 below.

...................................................[수학식 3]

........................................ [Equation 3]

의

은 에코채널 벡터

의 nullspace 기저벡터로 구성된 nulling 벡터를 구하는 함수 또는 이에 준하는 아래의 [수학식 4]와 같은 성질을 갖는 nulling 벡터

를 구하는 함수이다.Where preprocessing vector

of

Silver ecochannel vector

A function to find a nulling vector of the nullspace basis of, or a nulling vector with the same properties as in Equation 4 below.

This function finds.

.....................................................[수학식 4]

........................................ ... [Equation 4]

를 곱하여 재전송 신호를 만들고, 송신배열안테 나(240)로 인가된다. 이렇게 만들어져 송신배열안테나로 인가된 재전송신호는 에코채널을 통과할 때 [수학식 4]의 성질에 따라 중계기 수신안테나로 반향되지 않아 이후로부터 전송신호에 간섭을 주지 않는다.On the other hand, the echo signal removal module 230 is a transmission signal received from the vector generation module 220, echo signal and preprocessing vector

Multiply by to make a retransmission signal, it is applied to the transmission array antenna (240). The retransmission signal thus made and applied to the transmission array antenna is not echoed to the repeater reception antenna according to the property of [Equation 4] when passing through the echo channel, and thus does not interfere with the transmission signal thereafter.

That is, according to the generated preprocessing vector, Equation 1 completely removes an echo signal received through an echo channel according to the ZF (zero-forcing) property of Equation 4 as described above. It is redefined as [Equation 5].

.....................................[수학식 5]

Equation 5

Subsequently, the transmission array antenna 240 retransmits the retransmission signal received from the echo signal removing module to the receiving apparatus, and the receiving apparatus 300 receives the retransmission signal, which is not the following [Equation 2]. 6].

...............................[수학식 6]

Equation 6

는 0이 아닌 1-차원의 유효채널(effective channel)로서 첨부도면 도 1에 도시된 종래 SISO(single-input single-output)를 기반으로 하는 구조의

과 비교해 볼 때, 시스템 성능 저하가 없음을 알 수 있다. 즉, 송신배열안테나를 통해 빔포밍(공간다중화)이 가능하게 되어 반향신호가 에코채널을 통해 수신안테나로 인가되는 것을 미연에 방지한다.At this time,

Is a non-zero one-dimensional effective channel of the structure based on the conventional single-input single-output (SISO) shown in FIG.

Compared with, it can be seen that there is no system performance degradation. That is, beamforming (spatial multiplexing) is possible through the transmission array antenna, thereby preventing the echo signal from being applied to the reception antenna through the echo channel.

개의 수신배열안테나(250)와 송신안테나(260)를 이용하여 공간다중화를 이룬다.Hereinafter, a second embodiment according to the present invention will be described. The echo signal cancellation and echo channel derivation system according to the second embodiment is based on the system of the first embodiment, but the configuration of the relay 200 is different as shown in FIG. That is, in the first embodiment, the receiving antenna 210 and In this case, the spatial multiplexing is achieved through two transmission array antennas 240.

Spatial multiplexing is achieved using the two receiving array antennas 250 and the transmitting antennas 260.

개의 수신배열안테나와, 송신안테나 사이의

벡터채널

로 나타낼 수 있으며, 송신장치의 송신신호는

, 수신배열안테나가 수신하는 신호는

, 송신안테나가 재전송하는 신호는

, 그리고 수신장치가 수신하는 신호는

인 것으로 상정하며, 상기 상술한 바를 정리하면 아래의 [수학식 7]과 같은 신호모델로 정의 할 수 있다.Referring to FIG. 6, the echo channel is

Between the receiving array antenna and the transmitting antenna

Vector channel

The transmission signal of the transmitter is

The signal that the receiving array antenna receives

The signal that the transmitting antenna retransmits

And the signal that the receiver receives

It is assumed that the above-described bar can be defined as a signal model as shown in Equation 7 below.

...............................[수학식 7]

Equation 7

는 송신장치와 중계장치 사이의 채널벡터로서, 는 송신장치로부터

째 수신배열안테나 사이의 채널을 나타내고,

는 에코채널 벡터로서,

는 송신안테나와

째 수신배열안테나 사이의 채널을 나타내며,

는

개로 이루어진 수신배열안테나의 잡음 벡터이다. 시간

동안 수신배열안테나가 수신하는 신호

를 살펴보면, 송신장치로부터의 신호 외에 에코채널을 통해

이전 시간에 송신안테나로부터 재전송된 신호

가 에코채널을 통해 간섭신호로 반향됨을 알 수 있다.here,

Is the channel vector between the transmitter and the relay,

Channel between the receiving array antennas,

Is the echo channel vector,

With transmit antenna

The second channel between receiving array antennas,

Is

Noise vector of a receive array antenna time

Signals received by the array antenna

In addition to the signals from the transmitter,

Signal retransmitted from transmitting antenna in previous time

It can be seen that is reflected as an interference signal through the echo channel.

시간에 전송되어 수신장치(300)가 수신한 신호는 아래의 [수학 식 8]과 같이 나타낼 수 있다.Also,

The signal transmitted by the receiver 300 and received in time may be represented by Equation 8 below.

.....................................[수학식 8]

Equation 8

Referring to FIG. 7, the reception array antenna 250 applies a transmission signal received from the transmission device 100 and an echo signal through an echo channel to the vector generation module, and the vector generation module 220 transmits from the reception array antenna. A signal and an echo signal are applied to estimate an echo channel, and a post-processing vector is generated from the estimated echo channel through Equation 9 below.

...............................................[수학식 9]

......................... 9]

는 [수학식 10]과 같은 성질을 갖는다.Where post-processing vector

Has the same properties as in [Equation 10].

.....................................................[수학식 10]

........................................ ... [Equation 10]

를 곱하여 반향신호만을 제거하며, 재전송신호는 반향신호와의 간섭됨 없이 송신안테나(260)로 인가된다.The echo signal removing module 230 is a post-processing vector applied to the transmission signal and the echo signal received from the vector generating module 230 according to the property of [Equation 10].

Multiply by to remove only the echo signal, the retransmission signal is applied to the transmission antenna 260 without interfering with the echo signal.

According to the generated post-processing vector, Equation 7 completely eliminates the echo signal coming through the echo channel according to the ZF (zero-forcing) property of Equation 10, and redefined by Equation 11 below. Becomes.

................................[수학식 11]

Equation 11

는 송신장치(100)와 중계장치(200) 사이의 유효채널을 나타내며,

이므로,

의 통계적 특성은 상기 [수학식 1]의

와 동일하고,

와 상기 첨부도면 도 1에 도시된 채널

와 비교해 볼 때, 시스템의 성능 열화가 없음을 알 수 있다.At this time,

Denotes an effective channel between the transmitter 100 and the relay 200,

Because of,

Statistical characteristics of the above Equation 1

Same as

And the channel shown in FIG.

Compared with, it can be seen that there is no performance degradation of the system.

The rear-view transmitting antenna 260 receives the retransmission signal from the echo signal removing module and retransmits it to the receiving device 300, and at the same time, the retransmission signal is reflected to the receiving array antenna 250.

On the other hand, as shown in the accompanying drawings based on the system of the first and second embodiments described above, the relay device 200 may be composed of a transmitting array antenna 240 and a receiving array antenna 250. . Specifically, referring to FIGS. 9 and 10, the vector generation module 220 receives a transmission signal and an echo signal through an echo channel from the reception array antenna to generate a preprocessing vector through Equation 3 above. And a post-processing vector is generated according to Equation 9 above.

및 후처리 벡터를

를 곱하여 반향신호를 제거한다.The echo signal removing module 230 transmits a signal received from the vector generating module, an echo signal, and a preprocessing vector.

And post-processing vectors

Multiply by to remove the echo signal.

The transmitting array antenna 240 receives the retransmission signal from the echo signal removing module and retransmits it to the receiving device 300 and at the same time, the retransmission signal is reflected to the receiving array antenna 250.

In addition, as shown in FIG. 11, the relay apparatus 200 including the above-described reception array antenna 250, the vector generation module 220, the echo signal canceling module 230, and the transmission array antenna 240. ) Is also capable of relaying the transmission signal between the transmission device 100 consisting of a plurality of antennas and the reception device 300 consisting of a plurality of antennas, and multiplying the transmission signal by the generated pre- and post-processing vectors and echo signals. The transmission signal can be relayed without interference.

Hereinafter, a third embodiment according to the present invention will be described. The echo signal cancellation and echo channel derivation system according to the third embodiment is based on the system of the first embodiment.

In detail, referring to FIG. 12, the reception antenna 210 applies a transmission signal received from the transmission apparatus 100 and an echo signal through an echo channel to the PN signal generation module.

를 기반으로 한 아래의 [수학식 12]에 따라 서로 직교성질(orthogonal)을 갖는 PN(pseudorandom noise)신호를 생성하여 상기 송신신호와 가합하고, 이 PN신호가 가합된 재전송신호를 송신배열안테나(240)로 인가한다.The PN signal generation module 270 is a data vector defined in Equation 1 above.

Based on Equation 12 below, PN (pseudorandom noise) signals having orthogonal properties are generated and added to the transmission signal, and the retransmission signal to which the PN signal is added is transmitted to the transmission array antenna ( 240).

..........................[수학식 12]

Equation 12

는

째 안테나의 길이 의 PN신호의

째 원소를 나타내며,

,

,

는 각각

,

,

의 길이

인 벡터 표현으로, PN신호와는 아래의 [수학식 13]과 같이 자기상관(auto correlation)성질과 직교상관(cross correlation)성질을 갖는다.here

Is

Of the PN signal of the antenna length

The second element,

,

,

Are each

,

,

Length of

In the vector expression, the PN signal has an auto correlation property and a cross correlation property as shown in Equation 13 below.

........................[수학식 13]

Equation 13

라고 정의할 때,

시간 이후에 재전송되는 PN신호는 에코채널을 통해 수신안테나로 반향되어 상기 송신장치로부터 수신한 송신신호와 간섭으로 작용하고, 다시 PN신호의 재전송 주기(T)동안 누적된다.Here, the delay time that the first symbol of the PN signal enters the reception antenna along with the echo signal through the echo channel

Is defined as

The PN signal retransmitted after the time is echoed to the reception antenna through the echo channel to interfere with the transmission signal received from the transmission apparatus, and is accumulated again during the retransmission period T of the PN signal.

을 추정함으로써, 수신안테나(210)는 PN신호가 가합된 반향신호로부터 정확한

시간을 추정하여 반향신호로부터 에코채널을 도출한다.However, after receiving the signals, echo channel as shown in [Equation 14] below

By estimating the signal, the reception antenna 210 can accurately determine the echo signal from which the PN signal is added.

The time is estimated to derive the echo channel from the echo signal.

...............................[수학식 14]

Equation 14

The transmission array antenna 240 receives a retransmission signal including the PN signal from the PN signal generation module and retransmits it to the receiving device. At this time, the retransmission signal including the PN signal is partially reflected to the repeater reception antenna.

Subsequently, the reception antenna 210 receives the echo signal to which the PN signal is added, derives an echo channel from the PN signal, and the reception apparatus 300 receives the retransmission signal from the transmission array antenna.

On the other hand, using a training sequence (known sequences such as pilot, preamble, etc.) it is possible to remove the echo signal by deriving an echo channel according to the standard of symbol time initiated by the WiBro Spec.

The symbol time specifications that WiBro Spec has started are 115.2us for Orthogonal Frequency Division Multiplexing (OFDM), 87.2us for Transmit / receive Transition Gap (TGT), and 74.4us for Receive / transmit Transition Gap (RTG). Is defined as

It can be seen that the propagation delay according to the propagation path is 3us when the 1km cell is transmitted based on the symbol time as described above. Referring to FIG. 13, a pilot signal generation module 280 is shown. ) Generates a pilot signal during the TTG or RTG time and applies it to the transmit array antenna 240. At this time, since the pilot signal is transmitted and received during the TTG or RTG time, no signal other than the pilot signal is transmitted or received.

Behind the scene, the receiving antenna 210 receives a pilot signal from the transmitting array antenna 240 during the TTG or RTG time to derive an echo channel according to Equation 15 below.

................................................[수학식 15]

................................................[Math Equation 15

시간동안의 지연 후 샘플 시간동안 수신안테나에 수신되는 신호는 에코채널 값과 같다. 또한, 송신안테나(260)이 하나일 때는 파일럿 한 개, 즉 임펄스만을 전송하여 수신배열안테나(250)으로 수신된 값을 측정해 에코채널을 도출할 수도 있다. 보기를 들어, 한 개의 송신안테나로 1을 송신하였을 때, 각 수신 안테나로 수신된 값은 각 수신안테나와 송신안테나 사이의 에코채널 값이 된다.According to Equation 15, 1 is transmitted to any one antenna of the transmit array antenna during the first sample time 115.2 / 1024us of the pilot signal, and 1 is transmitted to the other antenna of the transmit array antenna at the next sample time. To have orthogonality over time,

The signal received at the receiving antenna during the sample time after the delay in time is equal to the echo channel value. In addition, when there is only one transmitting antenna 260, one pilot, that is, only an impulse may be transmitted to measure an value received by the receiving array antenna 250 to derive an echo channel. For example, when 1 is transmitted to one transmitting antenna, the value received by each receiving antenna becomes an echo channel value between each receiving antenna and the transmitting antenna.

를 수신한다. 이때 상기 [수학식 7]은 아래 [수학식 16]으로 다시 쓸 수 있다.In addition, it is also possible to derive an echo channel through the retransmission signal, which can be used for additional help in echo channel estimation, and in particular, independent echo channel estimation in the case of FIG. 5, FIG. Can be used in a way. That is, the reception array antenna 250 is a vector from the transmission antenna 260 and the vector defined in [Equation 1]

Receive At this time, Equation 7 may be rewritten as Equation 16 below.

........................................[수학식 16]

Equation 16

를 곱하여 아래 [수학식 17]과 같이 에코채널을 추정한다. 이때, 상기 [수학식 14]에서와 동일하게 지연시간

의 추정으로 재전송신호

에 대한 간섭은 없다고 가정한다.Retransmission signal in [Equation 16]

Multiply by to estimate the echo channel as shown in Equation 17 below. At this time, the delay time as in [Equation 14]

Retransmission signal by estimation of

Assume that there is no interference with.

.....................................................[수학식 17]

........................................ ... [Equation 17]

As described above and described with reference to a preferred embodiment for illustrating the technical idea of the present invention, the present invention is not limited to the configuration and operation as shown and described as described above, it is a deviation from the scope of the technical idea It will be understood by those skilled in the art that many modifications and variations can be made to the invention without departing from the scope of the invention. Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

1 is a view showing the configuration of a conventional interference cancellation system;

2 is a block diagram illustrating an echo signal cancellation and echo channel derivation system using multiple antennas according to a first embodiment of the present invention;

3 is a diagram illustrating a physical relationship between an echo signal cancellation system and an echo channel derivation system using multiple antennas according to a first embodiment of the present invention;

4 is a view sequentially showing that an echo signal is removed according to a first embodiment of the present invention;

5 is a block diagram illustrating an echo signal cancellation and echo channel derivation system using multiple antennas according to a second embodiment of the present invention;

6 is a diagram illustrating a physical relationship between an echo signal cancellation and an echo channel derivation system using multiple antennas according to a second embodiment of the present invention;

7 is a view sequentially illustrating that an echo signal is removed according to a second embodiment of the present invention;

8 is a block diagram illustrating an echo signal cancellation and echo channel derivation system including a transmission array antenna of a first embodiment and a reception array antenna of a second embodiment;

9 is a diagram illustrating a physical relationship between an echo signal cancellation and echo channel derivation system including a transmission array antenna of a first embodiment and a reception array antenna of a second embodiment;

FIG. 10 is a view sequentially illustrating that echo signals are removed according to an echo signal cancellation and echo channel derivation system including a transmission array antenna of a first embodiment and a reception array antenna of a second embodiment;

11 is a diagram showing the physical relationship of transmission signal relay between a plurality of transmitters and a plurality of receivers;

12 is a diagram illustrating deriving an echo channel through PN signal generation according to a third embodiment of the present invention;

13 is a diagram illustrating deriving an echo channel through pilot signal generation according to a third embodiment of the present invention;

** Description of symbols for the main parts of the drawing **

S: echo signal cancellation and echo channel derivation system using multiple antennas

100: transmitter 200: relay

210: reception antenna 220: vector generation module

230: echo signal cancellation module 240: transmission array antenna

250: receiving array antenna 260: transmitting antenna

270: PN signal generation module 280: pilot signal generation module

300: receiver

Claims (8)

A relay system for relaying a transmission signal between a transmitting device and a receiving device through a relay device comprising a receiving antenna and a transmitting array antenna, The relay device, A reception antenna for receiving a transmission signal from the transmission device and an echo signal through an echo channel, a vector generation module for generating a preprocessing vector and applying it to the echo signal removal module together with the transmission signal and the echo signal received from the reception antenna; And a echo signal removal module for removing echo signals by multiplying the preprocessing vector by the transmission signal and the echo signal, and a transmission array antenna for receiving the retransmission signal from the echo signal removal module and retransmitting the echo signal to the receiver. The preprocessing vector is generated through Equation 3, and the preprocessing vector

Silver ecochannel vector

Returns a nulling vector of the basis vectors of nullspaces in.

The echo signal cancellation and echo channel derivation system using multiple antennas, characterized in that the properties as shown in [Equation 4].

........................................ Equation 3

........................................ ... [Equation 4] delete A relay system for relaying a transmission signal between a transmitting device and a receiving device through a relay device comprising a receiving array antenna and a transmitting antenna, The relay device, A vector for generating a post-processing vector and receiving the transmission signal, the echo signal through the echo channel, and a post-processing vector from the transmitting apparatus and applying the echo signal to the echo signal removing module together with the transmission signal and the echo signal received from the receiving array antenna. A echo signal removal module for removing echo signals by multiplying a post-processing vector received from the vector generating module with a post-processing vector and an echo signal and a transmission signal, and a transmission for receiving a retransmission signal from the echo signal removal module and retransmitting it to the receiver. Including antennas, The post-processing vector is generated through Equation (9), and has an echo signal cancellation and echo channel derivation system using multiple antennas, characterized in that it has the same properties as in [Equation 10].

................................................[Math Equation 9

........................................ ... [Equation 10] delete A relay system for relaying a transmission signal between a transmitting device and a receiving device through a relay device comprising a receiving antenna and a transmitting array antenna, The relay device, A reception antenna for receiving a transmission signal and an echo signal through an echo channel from the transmission device; A PN signal generation module which generates PN signals having orthogonal properties to each other and adds them to the transmission signal, and applies a retransmission signal including the PN signal to the transmission array antenna; A transmission array antenna which receives a retransmission signal to which the PN signal is added from the PN signal generation module and transmits the retransmission signal to the receiving device; And A pilot signal generation module for generating a pilot signal during a TTG (Transmit / receive Transition Gap) or RTG (Receive / transmit Transition Gap) time; Echo signal cancellation and echo channel derivation system using multiple antennas comprising a. The method according to claim 5, The PN signal generation is made through [Equation 12],

Is

Of antenna length

Represents the th element,

,

,

Are each

,

,

A echo signal removal and echo channel derivation system using multiple antennas as a length vector representation of a PN signal and having auto correlation and cross correlation properties as shown in [Equation 13].

Equation 12

Equation 13 delete The method according to claim 5, Equation 16 and the retransmission signal

Echo signal cancellation and echo channel derivation system using multiple antennas, characterized in that to estimate the echo channel by multiplying by Equation 17.

Equation 16

........................................ ... [Equation 17]

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