KR20160092513A - Method and appratus for self interference cancelling - Google Patents

Abstract

Provided are an apparatus and a method for performing self-interference cancellation. The method includes a step of determining a filter coefficient of an analog filter operating in an analog region, and a step of cancelling self-interference generated in a receiving signal received from a node by a transmission signal transmitted to a node, based on the filter coefficient.

Description

[0001] METHOD AND APPARATUS FOR SELF INTERFERENCE CANCELING [0002]

The present disclosure relates to a method and apparatus for eliminating magnetic interference to a received signal generated by a transmitted signal.

The Inband Full Duplex (IFD) scheme is a technology that simultaneously receives signals while transmitting signals in the same frequency band at the same time. It is theoretically compared with the Half Duplex (HD) scheme adopted in current wireless communication systems It is possible to increase the wireless capacity up to twice.

1 is a conceptual diagram showing a half-duplex system. Referring to FIG. 1, a node of a half-duplex system transmits / receives a signal through a distributed time or frequency, that is, it uses different time or frequency resources for transmission / reception of signals, so it is easy to maintain orthogonality between signals transmitted and received. However, if half-duplex systems use different time or frequency resources for signal transmission and reception, resources may be wasted twice as compared to full-duplex systems. In particular, an IFD system is a solution to overcome the inefficiency of a half-duplex system, in which nodes of the IFD system can transmit and receive signals simultaneously (i. E., The same time resources) in the same band (i. The IFD system can theoretically increase the link capacity up to twice as much as the half-duplex system. The IFD method is a necessary technology for achieving the goal of increasing the traffic capacity of a small radio device such as a smart phone, which is pursued by 5-generation (5G) mobile communication, 1000 times.

However, the self interference signal needs to be removed to implement the IFD system. That is, a signal (magnetic interference signal) transmitted from the transmitter / receiver of the IFD system is apt to flow into the receiving end, and thus the magnetic interference signal has a problem of very strong magnetic interference with the effective reception signal. A technique for eliminating such magnetic interference is a Self-Interference Cancellation (SIC) technique.

One embodiment provides a transmit / receive node that performs self interference cancellation.

Another embodiment provides a method of magnetic interference cancellation.

According to one embodiment, a transmitting / receiving node that performs self interference cancellation is provided. The transmitting and receiving node includes an analog filter operating in the analog domain and a filter for determining the filter coefficient of the analog filter to remove the magnetic interference generated in the received signal received at the node by the transmission signal transmitted from the node .

The transmission signal at the transmission / reception node may be transmitted in the transmission phase included in the training field in the time domain and not transmitted in the empty phase included in the training field.

While the neighbor node of the transmitting / receiving node is operating in the transmission phase, the node may operate in the empty phase.

The transmitting and receiving node can operate in the same band full duplex (IFD) scheme or half duplex (HD) scheme.

At the transmitting / receiving node, the analog filter may be a finite impulse response (FIR) filter.

In the transmission / reception node, the control unit can operate in the digital domain.

The transmission / reception node further includes a channel / signal estimation unit for baseband sampling the transmission signal and the reception signal, and the control unit includes a baseband-sampled transmission signal and a baseband-sampled reception signal, a time delay value The filter coefficient can be determined based on the filter coefficient.

In the transmitting / receiving node, the channel / signal estimator may perform baseband sampling on a transmission signal, and then baseband sampling on a reception signal.

In the transmitting / receiving node, the channel / signal estimator may perform baseband sampling of a transmission signal and a reception signal at the same time.

The transmission / reception node transmits a transmission signal generated in a transmission module of a node to an antenna, transmits a reception signal received through an antenna to a reception module of the node, and distributes a magnetic interference signal due to magnetic interference to an analog filter And the like.

According to another embodiment, a method for canceling magnetic interference of a transmitting / receiving node is provided. The method includes the steps of determining a filter coefficient of an analog filter operating in an analog domain and removing magnetic interference generated in a received signal received by the node with a transmission signal transmitted from the node, .

In the magnetic interference cancellation method, the transmission signal may be transmitted in the transmission phase included in the training field in the time domain and not transmitted in the empty phase included in the training field.

In the magnetic interference cancellation method, the node can operate in the empty phase while the node's neighbor node is operating in the transmission phase.

In the magnetic interference cancellation method, a node can operate in the same band full duplex (IFD) scheme or half duplex (HD) scheme.

In the magnetic interference cancellation method, the analog filter may be a finite impulse response (FIR) filter.

The step of determining in the magnetic interference cancellation method may be performed in the digital domain by the control unit of the node.

The method of claim 1, further comprising: baseband sampling the transmitted signal and the received signal, wherein determining comprises: receiving a baseband sampled transmitted signal and a baseband sampled received signal and a time delay received from the analog filter And determining a filter coefficient based on the value.

The baseband sampling in the magnetic interference cancellation method may include baseband sampling the transmitted signal and then baseband sampling the received signal.

The baseband sampling in the magnetic interference cancellation method may include baseband sampling of the transmission signal and the reception signal simultaneously.

The magnetic interference cancellation method includes transmitting a transmission signal generated by a transmission module of a node to an antenna, transmitting a reception signal received through the antenna to a reception module of the node, inputting a magnetic interference signal by magnetic interference into an analog filter The method comprising the steps of:

According to the embodiment, by efficiently estimating the filter coefficient of the analog filter for removing the magnetic interference signal, it is possible to quickly adapt to changes in the surrounding environment over a wide bandwidth, achieve low cost (low memory utilization), low complexity and low power consumption .

1 is a conceptual diagram showing a half-duplex system.
2 is a conceptual diagram showing an IFD system according to an embodiment.
3 is a block diagram illustrating a transmitting / receiving node according to an embodiment.
4 is a block diagram illustrating a transmitting / receiving node according to another embodiment.
5 is a flowchart illustrating an analog filter control method according to an embodiment.
6 is a conceptual diagram illustrating a first protocol used for inter-node bi-directional IFD communication according to one embodiment.
7 is a conceptual diagram illustrating a second protocol used for inter-node bi-directional IFD communication according to another embodiment.
8 is a block diagram illustrating a node according to one embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. However, the present disclosure can be embodied in various different forms and is not limited to the embodiments described herein. In order to clearly illustrate the present invention in the drawings, parts not related to the description are omitted, and like reference numerals are given to similar parts throughout the specification.

Throughout the specification, a node is referred to as a terminal, a mobile station (MS), a mobile terminal (MT), an advanced mobile station (AMS), a high reliability mobile a subscriber station (SS), a portable subscriber station (PSS), an access terminal (AT), a user equipment (UE), a mechanical communication equipment and may include all or some of the functions of MT, MS, AMS, HR-MS, SS, PSS, AT, UE and the like.

Alternatively, the node may be a base station (BS), an advanced base station (ABS), a high reliability base station (HR-BS), a node B, An access point (AP), a radio access station (RAS), a base transceiver station (BTS), a mobile multihop relay (MMR) A relay node (RN) serving as a base station, an advanced relay station (ARS) serving as a base station, a high-reliability repeater (serving as a base station) a high reliability relay station (HR-RS), a small base station (femto BS), a home node B (HNB), a home eNodeB (HeNB), a pico BS, BS, RS, RN, ARS, HR-RS, small base station, etc.), and the like may be referred to as an ABS, a Node B, an eNodeB, an AP, a RAS, a BTS, It may comprise a portion or part of the functions of the.

2 is a conceptual diagram showing an IFD system according to an embodiment.

Referring to FIG. 2, in the IFD system, since each node experiences magnetic interference with a received signal of a transmission signal, the SIC technique is essential. For example, as an SIC technique, there is a propagation SIC technique of an antenna area physically spaced apart from a transmitting antenna and a receiving antenna. The radio SIC technique can lower the magnetic interference level by placing the transmitting / receiving antennas at a considerable distance, and the residual magnetic interference can be eliminated in the digital domain. However, the propagation SIC technique is difficult to apply to small-sized apparatuses because the gap between the transmitting and receiving antennas needs to be considerably secured. That is, since there is a physical restriction condition on the spacing between the transmitting and receiving antennas in the small apparatus, there is a need for a technique capable of performing the SIC without physically separating the transmitting and receiving antennas.

The SIC technology in the analog circuit area can be divided into the manual SIC technology and the active SIC technology. Passive SIC technology implements SIC using passive components, which can easily achieve SIC gain but has a limited amount of gain. On the other hand, active SIC technology is a technology that can achieve large SIC gain compared to manual SIC technology. However, conventional active SIC technology is difficult to maintain a high SIC gain while adapting quickly to changes in the surrounding environment over a wide bandwidth. In addition, there is a disadvantage that high cost (memory use, etc.), high complexity and high power are required.

3 is a block diagram illustrating a transmitting / receiving node according to an embodiment.

3, the transmitting and receiving node 100 according to one embodiment includes an antenna unit 110, which corresponds to an antenna domain, an analog circuit domain, and a digital domain, respectively, An analog circuit area transmission / reception unit 120, and a baseband digital area transmission / reception unit 130. In the present description, the transmitting / receiving node can operate in the IFD scheme or in the HD scheme.

The antenna unit 110 includes one transmitting antenna 111 and one receiving antenna 112. [ Accordingly, the transmitting / receiving node can obtain the SIC gain by the physical separation distance between the transmitting antenna 111 and the receiving antenna 112, and the spectral efficiency is limited to a level similar to that of the existing HD method. That is, since the antenna unit 110 of the transmission / reception node 100 according to the embodiment includes one antenna for transmission and reception, the spectrum of the transmission / reception node 100 in an ideal environment having no correlation between the antennas, The efficiency aspect is no different from the HD method which applies 2 × 2 multi-input multi-output (MIMO) spatial multiplexing.

The analog circuit area transceiver 120 includes an analog filter 121, a power amplifier (PA) 122, a low noise amplifier (LNA) 123, a mixer 124, An integrator 125, a local oscillator (LO) (not shown), a digital-to-analog converter (DAC) 126, an automatic gain controller (Not shown), and an analog-to-digital converter (ADC)

The analog filter 121 removes the magnetic interference signal flowing into the reception module via the reception antenna 120. [ At this time, an adaptive analog finite impulse response (FIR) filter may be used as the analog filter 121. The analog filter 121 can be designed in a simple manner so as to prevent performance deterioration due to variability of hardware elements. For example, the analog filter 121 may comprise a tap using N delay lines and an attenuator connected to each tap. At this time, the weights applied to the attenuators connected to the respective taps are generated by a channel / signal estimator 131 and a filter weight generator 133 included in the baseband digital domain transmitter / receiver 130 Whereby interworking between the analog circuit area transceiver 120 and the baseband digital area transceiver 130 can be implemented.

The power amplifier 122 amplifies the transmission signal converted into the RF signal by the mixer 124 and the local oscillator.

The low noise amplifying unit 123 amplifies the signal received through the receiving antenna 120 to reduce noise.

Mixer 124 to an analog signal of the base band is multiplied by a sine wave signal corresponding to the carrier frequency f _c generated by a local oscillator (mathematically multiplied).

The integrator 125 performs a mathematical multiplication of the output signal of the low noise amplifier and the sinusoidal signal corresponding to the carrier frequency of the local oscillator and performs a mathematical integration for each time interval corresponding to the period of the sinusoidal signal, Signal.

The DAC 126 converts the digital signal to an analog signal, and the ADC 127 conversely converts the analog signal to a digital signal.

The AGC adjusts the gain of the input signal to a desired reference level.

The baseband digital domain transceiver 130 includes a channel / signal estimator 131, a Tx data generator 132, and a controller 133. According to one embodiment, the baseband digital domain transmitter / receiver 130 may include a Rx data generator (not shown).

The channel / signal estimator 131 estimates the impulse response of the magnetic interference signal formed in the received signal y (t) in the time domain by the signal x (t) input from the analog filter 121. In addition, the channel / signal estimator 131 may be configured to perform a baseband equivalent oversampled or baseband sampled signal on x (t) and a baseband equivalent oversampled for y (t) Estimates the band-sampled signal, and transmits the estimation information according to the estimation to the control unit 133. [

The control unit 133 calculates the coefficient of the analog filter 121 based on the estimation information received from the channel / signal estimation unit 131 and transmits the calculated coefficient to the analog filter 121. Then, the coefficient calculated by the controller 133 may be applied to the analog filter 121.

The transmission data generation unit 132 performs encoding and modulation on data to be transmitted and the reception data generation unit demodulates and decodes the reception signal.

4 is a block diagram illustrating a transmitting / receiving node according to another embodiment.

Referring to FIG. 4, the transmitting / receiving node 200 according to another embodiment includes a single transmitting / receiving shared antenna as an antenna domain. In other words, unlike the transmitting / receiving node 100 according to the embodiment of FIG. 3, the transmitting / receiving node 200 according to another embodiment shown in FIG. 4 can transmit and receive signals through one antenna. As a result, the SIC gain of the antenna region can not be obtained through the transmitting / receiving node 200 according to another embodiment, but the spectrum efficiency can be maximized twice as compared with the conventional HD method, and the transmitting / Lt; / RTI >

 The transmitting and receiving node 200 according to another embodiment includes a distributor 240. The distributing unit 240 transmits a transmission signal generated by the transmitting module 220 to the antenna unit 210, And transmits the reception signal received through the antenna 210 to the reception module 230. At this time, due to the hardware characteristic of the distribution unit 240, a leakage signal may be generated, and a transmission signal corresponding to the leakage signal may be introduced into the reception module 230 as a magnetic interference signal. The distributor 240, which may be configured as an analog component, may include, for example, a circulator, or an electrical balance duplexer (EBD) that includes a hybrid transducer and a balance network. It is to be noted that any analog device or circuit having a function similar to that of the circulator or EBD may be applied as the distributor 240, and all of them can be included in the scope of the present invention.

4, the analog filter 250 removes a magnetic interference signal introduced into the receiving module 230 through the antenna unit 210 and the distribution unit 240. The input signal of the analog filter 250 may be a signal (that is, a transmission signal) passing through the PA or an internal signal of the distribution unit 240. In general, when a circulator is used as the distributor 240, the signal passed through the PA becomes the input signal of the analog filter 250, and when the EBD is used as the distributor 240, the input signal passes through the PA It can be a signal or an internal signal generated inside the filter.

The functions of the PA, the LNA, the mixer, the integrator, the DAC, the ADC, the AGC, the channel / signal estimator, the transmission data generator, and the controller 260 shown in FIG. Is the same as that of. Hereinafter, a method of removing magnetic interference of the transmitting / receiving node 200 and a method of determining a filter coefficient of the analog filter 250 according to an embodiment will be described in detail with reference to FIG.

5 is a flowchart illustrating a method of removing a magnetic interference according to an embodiment.

Referring to FIG. 5, the transmission signal generated in the transmission module is input directly to the analog filter as a magnetic interference signal or indirectly input to the analog filter as a leakage signal through the distribution unit (S501).

In the embodiment, it is assumed that the transmission signal x (t) of the RF band is band-limited to the bandwidth W [Hz]. In an embodiment, W may be the system bandwidth of the baseband signal, or may be d times oversampled bandwidth. For the sake of simplicity, it is assumed in the following description that W is d-times oversampled bandwidth. When the baseband equivalent signal of x (t) is x _b (t), x (t) can be expressed as Equation 1 below.

In Equation (1), P is the transmission power amplified by the PA. In general, if x (t) is band limited to bandwidth W, then x _b (t) is band limited to W / 2. x _b (t) is represented by the following equation (2).

In Equation (2), x [n] is x _b (n / W) and sinc (t) is given by Equation 3 below.

Equation (2), W / all the baseband waveform which the second band limitation by the coefficient given by the sample (i.e., x [n]) and an orthogonal basis (basis) {sinc (Wt- n)} n linear The sampling theorem that can be expressed as a linear combination. Further, the baseband equivalent signal y _b (t) for the received signal y (t) in the RF region is expressed by Equation (4) below.

In Equation (4), a _i ^b (t) is expressed by Equation (5).

In Equation (5), a _i (t) and τ _i (t) denote path attenuation and time delay caused by multipath i at time t, respectively. Then, the received signal y [m] obtained by baseband sampling yb (t) is expressed by Equation (6) below. y [m] is equal to y _b (m / W) (y [m] = y _b (m / W)).

The baseband sampled received signal y [m] may equivalently be regarded as a projection of Wsinc (Wt-n) of the received waveform y _b (t). (Mn = l) and y [m] can be expressed by Equation (7).

The right part of the right term of Equation (7) can be expressed by h _l [m] as shown in Equation (8).

Therefore, by expressing Equation (7) using Equation (8), the baseband received signal y [m] can be expressed as Equation (9).

_Hl [m] in Equation (8) is a mathematical representation of the lth (complex) channel filter tap (or the time domain impulse response of the channel) in sample m. The value of the channel filter tap is mainly a function of the multipath gain a _i ^b (t) when the time delay value τ _i (t) of multipath i is close to l / W. In the special case where the gain a _i ^b (t) of the multipath and the time delay τ _i (t) are time-invariant, Equation (8) can be expressed as Equation (10).

That is, in Equation (10), the channel is linear time-invariant. For convenience, the channel is assumed to be invariant when linear, and the received signal and (complex) channel model modeled in (9) and (10) Can be used for modeling the self interferenceed received signal y [m] at the time of entering the receiving module and the channel generated through the distributor and antenna. For example, the self-interfered received signal is mapped to y [m] in equation (9), the channel at this time is mapped to equation (10), and the magnetic interference signal is mapped to y [m-1] .

를 생성한다(S502). 즉,

는 아날로그 필터로 입력된 RF 영역의 신호 x(t)에 대응하는, 아날로그 필터의 출력이다. 이후

는 수신 모듈로 입력되고, ADC에서 샘플링되어

형태로 출력된다(S503). First, the analog filter outputs,

(S502). In other words,

Is the output of the analog filter corresponding to the signal x (t) in the RF domain input to the analog filter. after

Is input to the receive module, sampled at the ADC

(S503).

에 대한 퇴플리츠(Toeplitz) 행렬을 계산한다(S504).

에 대한 퇴플리츠 행렬은 수학식 11과 같다.The channel / signal estimator is configured to sample the baseband magnetic interference signal < RTI ID = 0.0 >

The Toeplitz matrix is calculated (S504).

Is expressed by Equation (11). &Quot; (11) "

에 대한 퇴플리츠 행렬을 바탕으로 주어진 채널의 시간 영역의 임펄스 응답을 추정한다(S505). 이때, y[m]은 수학식 12와 같고, 추정된 시간 영역의 임펄스 응답은 수학식 13과 같이 표현될 수 있다.In Equation (11), c means the number of non-causal elements (i.e., samples). The channel / signal estimator is configured to receive the baseband sampled received signal y [m]

The impulse response of the time domain of a given channel is estimated on the basis of the de-Pleitz matrix for the channel (S505). At this time, y [m] is equal to Equation (12), and the impulse response of the estimated time domain can be expressed as Equation (13).

는 퇴플리츠 행렬

의 의사 역행렬(pseudo-inversion)이다. In Equation (13)

The Pleiades procession

(Pseudo-inversion).

Equation (10) can be rewritten as Equation (14) by substituting Equation (5) into Equation (10).

Equation (14) means the time domain impulse response of the channel of the received signal (mainly magnetic interference signal) formed in the receiving module. In Equation (14), τ _i denotes an actual time delay value for multipath i, and is the time delay value of the transmission signal received from the analog filter by the control unit.

을 수학식 14를 바탕으로 수학식 15와 같이 표현할 수 있다.Therefore, the control unit calculates the time domain impulse response < RTI ID = 0.0 >

Can be expressed as Equation (15) based on Equation (14).

는 제어부에서 생성하는 아날로그 필터를 위한 필터 계수를 의미한다. 즉, 제어부는 아날로그 필터로부터 수신한, 송신 신호의 시간 지연 값과, 채널/신호 추정부에서 추정된 채널 임펄스 응답을 바탕으로, 아날로그 필터의 필터 계수를 결정할 수 있다(S506). 이때, 제어부에서 결정된 필터 계수는 아날로그 필터와의 연동을 통해 아날로그 필터에 적용될 수 있다. 이때, 수학식 15의 행렬 표현은 수학식 16과 같다.In Equation (15), d _j denotes a time delay value due to a filter tap j (corresponding to multipath delay i in Equation (14)) input from an analog filter,

Means a filter coefficient for the analog filter generated by the control unit. That is, the controller can determine the filter coefficient of the analog filter based on the time delay value of the transmission signal received from the analog filter and the channel impulse response estimated by the channel / signal estimator (S506). At this time, the filter coefficient determined by the control unit can be applied to the analog filter through interlocking with the analog filter. At this time, the matrix expression of the expression (15) is expressed by the expression (16).

In Equation (16), s can be expressed as Equation (17).

In Equation (16), a ^b can be expressed as Equation (18).

는 추정을 통해 미리 알고 있는 벡터이므로, 수학식 17을 통해 알고 있는 행렬이므로, a ^b는 s ^†

로 계산될 수 있다. 하지만, 일반적으로 s ^†가 정확하게 존재하지 않기 때문에, 제어부는 필터 계수

를 추정한다. 아래에서는 필터 계수

를 추정하는 방법을 설명한다. In Equation (16)

Is a known vector through estimation, and is a matrix known from equation (17), a ^b is s ^†

Lt; / RTI > However, since s ^† is generally not exactly present,

. The filter coefficients

Will be described.

는 아래와 같이 추정될 수 있다. 먼저, 제어부는 수학식 16 내지 수학식 18을 바탕으로 초기 벡터를 순차적으로 정의한다. 수학식 19는 순차적으로 정의된 초기 벡터를 나타낸다.The filter coefficient < RTI ID = 0.0 >

Can be estimated as follows. First, the controller sequentially defines an initial vector based on Equations (16) to (18). Equation (19) represents a sequentially defined initial vector.

In Equation 19, 0 means a zero vector. Next, the control unit updates a ^b on the basis of Equation (20).

(j=0, 1, ..., N-1)을 제거하여 필터 계수

를 결정한다. 이때, 수학식 19 및 수학식 20을 통해 최종적으로 업데이트 된 필터 계수

는 복소수일 수 있다.At this time, the control unit can repeatedly apply Equation (20) according to a predetermined number of times. Then, the control unit calculates, for each element of the updated a ^b ,

(j = 0, 1, ..., N-1)

. At this time, the filter coefficients finally updated through the equations (19) and (20)

Can be a complex number.

는 아래와 같이 추정될 수 있다. 먼저, 수학식 16에 의해 추정된 필터 계수 벡터

에 대응하는 새로운 필터 계수 벡터

가 정의된다. 새로운 필터 계수 벡터

는 수학식 21과 같다.The filter coefficient according to another embodiment

Can be estimated as follows. First, the filter coefficient vector estimated by the equation (16)

Lt; RTI ID = 0.0 >

Is defined. New filter coefficient vector

(21).

) 및 imag(

)는 각각

의 성분별 실수값 벡터 및

의 성분별 허수값 벡터를 나타낸다. 그리고 수학식 17에 대응하는 새로운 S는 아래 수학식 22와 같이 정의된다.In Equation 21, real (

) And imag (

) Are respectively

The real component value vector and

Lt; / RTI > vector. And a new S corresponding to Equation (17) is defined as Equation (22) below.

는 아래 수학식 23과 같다.Then, a matrix of each element of S in the equation (22)

Is expressed by Equation 23 below.

가 아래 수학식 24과 같이 정의된다.Then, the following equation

Is defined as Equation (24) below.

The control unit sequentially defines the initial vectors based on the equations (21) to (24). Equation 25 represents a sequentially defined initial vector.

를 업데이트 한다.Next, based on Equation (26)

Lt; / RTI >

의 성분

를 아날로그 필터의 계수로 결정한다.At this time, the control unit can repeatedly apply Equation (26) according to the predetermined number of times. Thereafter,

Component of

Is determined as the coefficient of the analog filter.

는 아래와 같이 추정될 수 있다. 또 다른 실시예에 따른 필터 계수

의 추정 방법에 따르면, 최종적으로 업데이트 된

는 실수이다. 먼저, 수학식 18의 벡터 a ^b의 성분 중, 양의 실수값을 갖는 초기

를 임의로 선택한다. 명심할 사항은 초기

를 선택하는 모든 가능한 방법은 본 발명의 범위에 포함된다는 것이다. 다음 제어부는, 수학식 11, 수학식 12, 수학식 16, 수학식 17, 그리고 수학식 18을 바탕으로 수학식 27에 기재된 코드를 실행하여

를 반복적으로 업데이트 하고,

를 결정한다.According to another embodiment,

Can be estimated as follows. According to another embodiment,

According to the estimating method of the present invention,

Is a mistake. First, among the components of the vector a ^b in Equation (18), an initial value having a positive real value

. Remember that the initial

≪ / RTI > are within the scope of the present invention. The next control unit executes the code described in Equation (27) based on Equations (11), (12), (16), (17), and

, ≪ / RTI >

.

In Equation 27, NumOFIterations is the total number of times the code is repeatedly executed, and A represents the gain step value of the attenuation. For example, Δ can be 0.25 [dB], and the range of gain values for adjustable attenuation can be limited to 0 [dB] to 31.5 [dB]. It should be borne in mind that all possible gain calculation methods, including methods for calculating SIC gains such as G ₁ and G _{2 in} equation (27), fall within the scope of the present invention.

를 추정하는 위 세가지 방법에 따르면,

는 제어부의 특정 시간 구간에서의 연산을 통해 한 번에 결정되기 때문에, 송수신 노드의 주변 환경이 변화하더라도 송수신 노드는 곧바로 주변 환경에 적응할 수 있다. 위에서 설명된 실시예에서, 시간 영역의 신호(아날로그 필터의 입력 신호 또는 수신 신호 등)가 사용되었지만 주파수 영역의 신호(아날로그 필터의 입력 신호 또는 수신 신호 등)가 사용될 수도 있으며, 본 발명의 범위는 이에 한정되지 않는다.

According to the above three methods,

Is determined at a time through an operation in a specific time interval of the control unit. Therefore, even if the surrounding environment of the transmission / reception node changes, the transmission / reception node can immediately adapt to the surrounding environment. In the embodiment described above, signals in the time domain (such as the input signal or the received signal of the analog filter) are used, but signals in the frequency domain (such as the input signal or the received signal of the analog filter) But is not limited thereto.

6 is a conceptual diagram illustrating a first protocol used for inter-node bi-directional IFD communication according to one embodiment.

The first protocol used in the inter-node bi-directional IFD communication according to one embodiment can be applied when the first node and the second node, i.e. two neighboring nodes, perform bi-directional IFD communication. Referring to FIG. 6, each node includes an IFD communication period 610 and an IFD training field 620 in the time domain.

In the IFD communication period 610, the first node and the second node can transmit desired signals and receive / restore desired signals, respectively. Each node may perform removal of the magnetic interference signal over the entire period of the IFD communication interval 610. [

, y[m],

등의 SIC 파라미터를 추정한다. 예를 들어, 각 노드는 수신 모듈에 유입된 임의의 자기 훈련 신호로부터

(또는 y[m])을 추정(예를 들어, 기저대역 샘플링)하고, 바로 이어서 수신 모듈에 유입된 자기 훈련 신호로부터 y[m](또는

)을 추정한다. 또는, 각 노드는 수신 모듈에 유입된 임의의 자기 훈련 신호로부터

및 y[m]을 한꺼번에 추정한다. 이때, 각 노드가

및 y[m]을 한꺼번에 추정하기 위해서, 각 노드는 하나의 RF 신호에서 기저대역 신호로 자기 훈련 신호를 변환하는데 필요한,

의 추정에 요구되는 하드웨어 그룹(예를 들어, 다운 컨버터, AGC, ADC 등) 및 y[m]의 추정에 요구되는 하드웨어 그룹을 별도로 갖고 있을 필요가 있다. 다만 명심할 사항은 SIC 파라미터를 추정하기 위해 최적으로 설계된 모든 IFD 훈련 필드(620)의 구체적인 구조(시간영역/주파수영역)는 모두 본 발명의 범위에 포함된다는 것이다. The IFD training field 620 includes a transmitting phase and an empty phase. In the transmission phase, each node transmits a training signal (tranining signal) and uses its own training signal

, y [m],

And so on. For example, each node may receive a signal from any self-

(Or baseband sampling) y [m] (or y [m]) from the received training signal, and y [m]

). Alternatively, each node may receive a self-training signal

And y [m] at a time. At this time,

And y [m], each node is required to convert the self-training signal from one RF signal to a baseband signal,

(For example, a down converter, an AGC, an ADC, and the like) required for the estimation of y [m], and a hardware group required for estimation of y [m]. It is to be noted that the specific structure (time domain / frequency domain) of all IFD training fields 620 optimally designed to estimate the SIC parameter is included in the scope of the present invention.

On the other hand, in the empty phase, each node operates in the reception mode without transmitting any signal. In the two nodes that perform bidirectional IFD communication between the nodes, the transmission phase and the empty phase are staggered from each other. That is, while the first node is in the transfer phase, the second node is in the empty phase and the first node is in the empty phase while the second node is in the transfer phase. Referring to FIG. 6, when a first node transmits a training signal in a transmission phase, a signal transmitted from a second node is not received in a reception module of the first node. In one embodiment, the empty phase exists for each node to better estimate the SIC parameter in the transmission phase. That is, each node can estimate the SIC parameter more effectively than when the signal transmitted from the counterpart is input, i.e., interference exists.

7 is a conceptual diagram illustrating a second protocol used for inter-node bi-directional IFD communication according to another embodiment.

The second protocol used in the inter-node bi-directional IFD communication according to another embodiment may be applied when the first node, the second node and the third node, i.e., three neighboring nodes, perform bi-directional IFD communication. 7, the first node includes an HD transmission communication field 720 and an IFD training field 710 in a time domain, a second node includes an IFD communication field 730 in a time domain, And an IFD training field 710. The third node includes an HD reception communication field 740 and an IFD training field 710 in the time domain.

The first node operates in the HD mode in the HD transmission communication interval 720 to transmit a desired signal and does not transmit any signal in the IFD training field 710 so that the second node can effectively estimate the SIC parameter. That is, the IFD training field 710 of the first node is the empty phase 712.

The third node operates in the HD mode in the HD receive communication interval 740 to receive the desired signal and does not transmit any signal in the IFD training field 710 so that the second node can effectively estimate the SIC parameter. That is, the IFD training field 710 of the third node is also the empty phase 712.

The second node transmits the training signal in the IFD training field 710, thereby estimating the SIC parameter through the self training signal. For the method of estimating the SIC parameter based on the self-training signal at the second node, the method described in Fig. 6 can be applied. In addition, the second node operates in the IFD mode in the IFD communication period 730 and receives / restores a desired signal from the first node while transmitting a desired signal to the third node. The second node may perform the removal of the magnetic interference signal using the SIC parameter estimated in the IFD training field 710 throughout the IFD communication interval 730. [

As described above, according to the embodiment, by efficiently estimating the filter coefficient of the analog filter for the removal of the magnetic interference signal, it is possible to adapt quickly to changes in the surrounding environment over a wide bandwidth and to achieve a low cost (low memory utilization), low complexity, Can be achieved.

8 is a block diagram illustrating a node according to one embodiment.

8, a node 800 includes a processor 810, a memory 820, and a wireless communication unit 830. The memory 820 may be coupled to the processor 810 to store various information for driving the processor 810 or at least one program executed by the processor 810. [ The wireless communication unit 830 may be connected to the processor 810 to transmit and receive wireless signals. The processor 810 may implement the functions, steps, or methods suggested in the embodiments of the present disclosure. At this time, the wireless interface protocol layer in the wireless communication system according to an embodiment of the present invention can be implemented by the processor 810. [ The operation of node 800 in accordance with one embodiment may be implemented by processor 810. [

In an embodiment of the present disclosure, the memory may be located inside or outside the processor, and the memory may be connected to the processor through various means already known. The memory may be any type of volatile or nonvolatile storage medium, e.g., the memory may include read-only memory (ROM) or random access memory (RAM).

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

Claims (20)

A transmitting / receiving node for performing self interference elimination,
An analog filter operating in the analog domain that removes magnetic interference generated in the received signal received at the node by the transmitted signal transmitted by the node,
A controller for determining a filter coefficient of the analog filter,
Gt; The method of claim 1,
Wherein the transmission signal is transmitted in a transmission phase included in a training field in a time domain and is not transmitted in an empty phase included in the training field. 3. The method of claim 2,
Wherein the node operates in the empty phase while a neighbor node of the node is operating in the transmission phase. The method of claim 1,
Wherein the node operates in an in-band full duplex (IFD) scheme or a half-duplex (HD) scheme. The method of claim 1,
Wherein the analog filter is a finite impulse response (FIR) filter. The method of claim 1,
Wherein the control unit operates in a digital domain. The method of claim 6,
A channel / signal estimator for baseband sampling the transmission signal and the reception signal,
Further comprising:
Wherein the controller determines the filter coefficients based on the baseband sampled transmitted signal and the baseband sampled received signal and a time delay value received from the analog filter. 8. The method of claim 7,
Wherein the channel /
And baseband-samples the transmitted signal and then baseband-samples the received signal. The method of claim 1,
Wherein the channel /
And the base station samples the transmission signal and the reception signal at the same time. The method of claim 1,
And transmitting the received signal received through the antenna to a receiving module of the node, and transmitting the magnetic interference signal generated by the magnetic interference to the analog filter Distributing portion
Further comprising: a transmitting and receiving node. A method for removing magnetic interference in a transmitting / receiving node,
Determining a filter coefficient of an analog filter operating in the analog domain, and
Removing, based on the filter coefficient, magnetic interference generated in a received signal received at the node by a transmitted signal transmitted at the node
/ RTI > 12. The method of claim 11,
Wherein the transmission signal is transmitted in a transmission phase included in a training field in a time domain and not in an empty phase included in the training field. The method of claim 12,
Wherein the node is operating in the empty phase while a neighbor node of the node is operating in the transmission phase. 12. The method of claim 11,
Wherein the node operates in an in-band full duplex (IFD) scheme or a half-duplex (HD) scheme. 12. The method of claim 11,
Wherein the analog filter is a finite impulse response (FIR) filter. 12. The method of claim 11,
Wherein the determining is performed in a digital domain by a control of the node. 17. The method of claim 16,
The baseband sampling of the transmission signal and the reception signal
Further comprising:
Wherein the determining comprises:
Determining the filter coefficients based on the baseband sampled transmitted signal and the baseband sampled received signal and a time delay value received from the analog filter,
/ RTI > 8. The method of claim 7,
Wherein the baseband sampling comprises:
Baseband sampling the transmitted signal, and then baseband sampling the received signal
/ RTI > The method of claim 17,
Wherein the baseband sampling comprises:
Sampling the transmission signal and the reception signal simultaneously at baseband
/ RTI > 12. The method of claim 11,
And transmitting the received signal received through the antenna to a receiving module of the node, and transmitting the magnetic interference signal generated by the magnetic interference to the analog filter Step
Further comprising the steps of:

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