KR101550110B1 - Widely-linear framework for estimation of mimo systems - Google Patents

Abstract

송신 포트 및

수신 포트를 갖는 다중-입력 다중-출력 (MIMO) 시스템에 대한 제1 채널 행렬 및 제 2 채널 행렬을 추정하는 단계; 상기

수신 포트를 사용하여 상기 MIMO 시스템을 통한 상기 입력 심볼 행렬 P의 송신에 응답하여 출력 심볼 행렬 Y를 결정하는 단계; 상기 입력 심볼 행렬 P에 기초하여 의사-역(pseudo-inverse) 행렬

를 생성하는 단계; 및 상기 의사-역 행렬

및 상기 출력 심볼 행렬 Y를 사용하여 광의 선형 프레임워크에서의 상기 MIMO 시스템을 모델링하기 위하여 제 1 채널 행렬 H 및 제 2 채널 행렬 G를 추정하는 단계를 포함한다.A system and method for estimating and modeling a communication system in a linear framework of light is provided. In an aspect, a system and method may generate an input symbol matrix P for transmission over a MIMO system,

The transmit port and

Estimating a first channel matrix and a second channel matrix for a multiple-input multiple-output (MIMO) system having a receive port; remind

Determining an output symbol matrix Y in response to the transmission of the input symbol matrix P through the MIMO system using a receive port; Based on the input symbol matrix P , a pseudo-inverse matrix < RTI ID = 0.0 >

≪ / RTI > And the pseudo-inverse matrix

And estimating a first channel matrix H and a second channel matrix G to model the MIMO system in a linear framework of light using the output symbol matrix Y. [

Description

[0001] WIDELY-LINEAR FRAMEWORK FOR ESTIMATION OF MIMO SYSTEMS FOR MIMO SYSTEM [0002]

The present invention relates to a communication system. More particularly, to systems and methods for channel estimation in telecommunication systems such as wired, wireless and optical telecommunications systems.

This section introduces aspects that may be useful in facilitating a better understanding of the systems and methods disclosed herein. Accordingly, the description of this section should be read in this light and should not be construed or interpreted as an acknowledgment as to whether or not it is in the prior art.

BACKGROUND OF THE INVENTION Multiple-input-multiple-output (MIMO) systems are increasingly used in communication systems such as wireless or optical communication systems. A MIMO system employs multiple ports at the transmitting end and at the receiving end of a communication medium (e.g., optical fiber in a public or optical system of a wireless system) to provide communication between the transmitting end and the receiving end while maintaining radio bandwidth and power limitations. Thereby improving the data communication rate.

The MIMO transmitter multiplexes the outgoing signal stream into multiple signal streams and transmits the signal stream from a separate transmit port over a potentially noisy communication channel (e.g., public or fiber) And transmits the symbol signal stream. MIMO utilizes multiple signal propagation paths between transmit and receive ports to increase throughput, reduce bit error rate and reduce transmit power of transmitted symbols.

Successful decoding and reconstruction of the signal stream received by the multiple receive ports of the MIMO receiver into the transmitted symbol signal stream is typically performed by estimating or modeling the noisy channel through which the signal stream is transmitted and received by the MIMO system .
The technology underlying the present invention is disclosed in U.S. Patent No. 7,813,421 (Oct. 12, 2010) and U.S. Patent Application Publication No. 2007/0026833 (Feb. 1, 2007).

A system and method for channel estimation of a MIMO communication system using widely linear signal processing of light is provided. While the present invention is applicable to MIMO telecommunication systems and is described herein with particular reference, it will be appreciated that the principles of the present invention may be applied to other signal processing systems and applications.

송신 포트를 갖는 송신기를 경유하여 통신 채널을 통한 송신을 위해

입력 심볼 행렬 P를 생성하고 -

은

초과임 - , 상기 통신 채널을 통한 상기 입력 심볼 행렬 P의 송신에 응답하여, 수신기의

수신 포트에서 수신된

출력 심볼 행렬 Y를 결정하고, 상기 입력 심볼 행렬 P에 기초하여

의사-역 행렬

를 생성하고, 상기 의사-역 행렬

및 상기 출력 심볼 행렬 Y를 사용하여 상기 통신 채널에 대한 제 1 채널 행렬 H 및 제 2 채널 행렬 G를 추정하는 것을 포함한다.In an aspect, a system and method includes:

For transmission over a communication channel via a transmitter with a transmit port

Generates an input symbol matrix P and -

silver

In response to the transmission of the input symbol matrix P over the communication channel,

Received on the receive port

Determines an output symbol matrix Y , and based on the input symbol matrix P

Pseudo-inverse matrix

And the pseudo-inverse matrix

And estimating a first channel matrix H and a second channel matrix G for the communication channel using the output symbol matrix Y. [

를 사용하여 상기 제 1 채널 행렬 H 및 상기 제 2 채널 행렬 G를 추정하는 것을 포함한다.In another aspect, a system and method,

And estimating the first channel matrix H and the second channel matrix G using < RTI ID = 0.0 >

을 사용하여 모델링하기 위해 추정된 제 1 채널 행렬 H 및 추정된 제 2 채널 행렬 G를 사용하는 것을 포함하며,

는 상기 통신 채널을 통해 상기

송신 포트를 경유하여 송신되는 입력 신호 스트림을 나타내는 입력 벡터이고,

는 상기 입력 벡터의 공액의 표현이고,

은 상기 통신 채널에 기인하는 독립적이고 동일하게 분포된 가우시안 잡음의 벡터 표현이고,

는 상기 통신 채널을 통해 상기

수신 포트에서 수신된 출력 신호 스트림의 출력 벡터 표현이다.In another aspect, a system and method are provided that allow the operation of the transmitter,

Using an estimated first channel matrix H and an estimated second channel matrix G to model using < RTI ID = 0.0 >

Via the communication channel,

An input vector representing an input signal stream to be transmitted via a transmission port,

Is a conjugate representation of the input vector,

Is a vector representation of independent and identically distributed Gaussian noise due to the communication channel,

Via the communication channel,

Is an output vector representation of the output signal stream received at the receive port.

실수값 행렬

를 생성하고, 상기 입력 심볼 행렬 P를 결정하기 위해

를 사용하는 것을 포함한다.In another aspect, a system and method are disclosed that have the same < RTI ID = 0.0 >

Real-valued matrix

To determine the input symbol matrix P ,

Lt; / RTI >

를 구축하고 -

는 상기 파일럿 심볼 행렬 P의 공액 행렬임 - ,

를 연산함으로써 상기 의사-역 행렬

를 생성하는 것을 포함하며, 상기

는

의 에르미트 행렬이고,

는 가역적이다.In another aspect, a system and method are disclosed that use an enhanced pilot matrix < RTI ID = 0.0 >

And -

Is a conjugate matrix of the pilot symbol matrix P ,

And the pseudo-inverse matrix

, Wherein said step

The

, ≪ / RTI >

Is reversible.

의 다중-노드 이진 트리를 구축함으로써, 상기 실수값 행렬

를 생성하는 것을 포함하고, 다중-노드 이진 트리의 특정 레벨에서 적어도 하나의 부모 노드

는 관계

및

를 사용하여 다중-노드 이진 트리의 후속 레벨에서 2개의 자녀 노드로 확장되고,

는

의 부정을 나타내고,

은 상기 트리의 특정 레벨을 나타내고,

은 상기 트리의 특정 레벨에서의 하나 이상의 노드를 식별한다.In another aspect,

Node binary tree, the real-valued matrix < RTI ID = 0.0 >

Node binary tree at a particular level of the multi-node binary tree,

Relationship

And

Lt; / RTI > is extended to two child nodes at a subsequent level of the multi-node binary tree,

The

And

Represents a particular level of the tree,

Identifies one or more nodes at a particular level of the tree.

송신 포트 및 상기

수신 포트는 안테나이다. 다른 양태에서, 상기 통신 채널은 유선 통신 채널이며, 송신 포트 및 수신 포트는 선을 통해 서로 상호접속된 데이터 포트이다. 또 다른 양태에서, 통신 채널은 광 통신 채널이며, 송신 포트 및 수신 포트는 광섬유를 통해 상호 접속된 광 데이터 포트이다.
In an aspect, the communication channel is a wireless medium,

The transmission port and the above-

The receiving port is an antenna. In another aspect, the communication channel is a wired communication channel, and the transmitting port and the receiving port are data ports mutually interconnected via a line. In another aspect, the communication channel is an optical communication channel, and the transmitting port and receiving port are optical data ports interconnected through optical fibers.

1 shows an example of a MIMO system according to an aspect of the present invention.
Figure 2 shows a linear block diagram representation of light in a MIMO system in accordance with an aspect of the present invention.
Figure 3 shows a linear block diagram representation of another light in a MIMO system in accordance with an aspect of the present invention.
4 illustrates an exemplary process for estimating a channel matrix of a MIMO system in a linear framework of light in accordance with an aspect of the present invention.
FIG. 5 shows a block diagram relationship for estimating a channel matrix using the process shown in FIG.
Figures 6 (a) and 6 (b) show an example for constructing a tree to determine a pilot matrix according to an aspect of the present invention.
Figure 7 shows an example of an apparatus for implementing various aspects of the present invention.

Various aspects of the invention are described below with reference to the accompanying drawings, in which some illustrative embodiments are shown. Like numbers refer to like elements throughout the description of the drawings.

The term "or ", as used herein, unless otherwise indicated (e.g.," or another "or" or alternatively "), is non-exclusive. Also, as used herein, the words used to describe the relationship between elements should be broadly interpreted to include the presence of a direct relationship or intervening elements, unless otherwise indicated. For example, when an element is referred to as being "connected " or " coupled" to another element, the element may be directly connected or connected to another element, or intervening elements may be present. Conversely, when an element is referred to as being "directly connected" or "directly connected" to another element, there are no intervening elements. Likewise, words such as " between ", "adjacent ", and the like should be interpreted in a similar manner.

1 shows a block diagram of a MIMO communication system 100 in accordance with an embodiment of the present invention. The MIMO communication system 100 includes a MIMO transmitter 110 and a MIMO receiver 120. The MIMO transmitter 110 includes a plurality of transmit ports 112-114 and the MIMO receiver 120 includes a plurality of receive ports 122-124. MIMO transmitter 110 is configured to generate a plurality of signal stream (t ₁ to t _T) from the transmission bit sequence 140, for transmission over a MIMO channel 130. Meanwhile, the MIMO receiver 120 is configured to generate the output bit sequence 150 by recovering the original transmitted bit sequence 140 from the plurality of signal streams ( r ₁ to r _R ) received from the MIMO channel 130 .

In communication system 100, each transmit port (112 to 114) at the MIMO transmitter 110 transmits a signal stream (t _i) via a MIMO channel 130, where the index i is from 1 to T , Which represents the total number of transmit ports 112-114. For example, the i- th transmitting port may transmit the signal stream t _i so that the final transmitting port 114 transmits the signal stream t _T while the first transmitting port 112 transmits the signal stream t ₁ Can be transmitted.

In the MIMO receiver 120, each receive port 122 through 124 receives a signal stream r _j from the MIMO channel 130, where the index j is in the range of 1 to R, To 124). For example, a jth receiving port may be coupled to a signal stream r _j such that the first receiving port 122 receives the signal stream r ₁ while the last receiving port 124 receives the signal stream r _R . It is to be understood that the transmitter 110 and the receiver 120 may comprise any suitable number of ports to implement the MIMO configuration.

As used herein, the term "stream" refers to a sequence of signals or data. For example, the signal stream t _i may comprise one or more signals (e.g., symbols) that are transmitted sequentially. Similarly, the signal stream r _j may comprise one or more signals (e.g., symbols) that are received sequentially. Further, the MIMO system may be a wireless MIMO system, a wired MIMO system, or a optical MIMO system. When the MIMO system is implemented as a wireless MIMO communication system (as shown in the example of FIG. 1), the ports 112-114 and 122-124 may be antennas and the MIMO channel 130 may be an air Lt; / RTI > Alternatively, the ports 112-114 and 122-124 may be wired or optical ports, and the MIMO channel 130 may be a wire (e. G., ≪ RTI ID = 0.0 > For example, traces, or optical fibers.

In an aspect, the transmitter 110 is configured to encode the transmit bit sequence 140 for error detection and correction. By encoding the transmitted bit sequence 140, an error that may occur during the transmission of the bit sequence 140 over the MIMO channel 130 can be detected and corrected at the receiver 120. The encoded bit sequence can be divided into T bit-stream for modulation and transmission as each signal stream (t ₁ to t _T).

In one aspect, the T encoded bit streams are mapped (e.g., modulated) to a set of symbols on a constellation plane prior to transmission via communication medium 130. For example, the transmitter 110 may generate the symbols ( x ₁ through x _T ), respectively, by mapping each bit stream to points on the constellation plane. In mapping the bit stream to a symbol, the transmitter 110 may be configured to apply any suitable modulation technique, such as Pulse Amplitude Modulation (PAM) , Binary Phase Shift Keying (BPSK), and the like.

In an aspect, the transmitter 110 is configured to convert the symbol stream into an analog RF signal that is transmitted over the MIMO channel 130. The transmission port (112 to 114) can respectively receive and transmit the RF signal as an analog signal stream (t ₁ to t _T) via a MIMO channel 130. Alternatively, converting the symbol stream into an analog RF signal for transmission as the transmission port (112 to 114) is a signal stream (t ₁ to t _T) through the received symbol streams, and MIMO channel 130. In other embodiments, each . ≪ / RTI >

Between the T transmit ports 112-114 and the R receive ports 122-124, the MIMO channel 130 acts as a transmission medium for a signal (e.g., symbol) stream. In the case of transmitting the transmission port (112 to 114) a signal stream (t ₁ to t _T), respectively, which signal stream (t ₁ to t _T) it will be affected by channel conditions such as interference as well as noise easily, And may be received as signal streams r ₁ to r _R at receive ports 122 to 124.

송신 포트 및

수신 포트를 갖는 MIMO 시스템에 대한 물리적인 MIMO 채널은 협의 선형(strictly-linear)(SL) 시스템

으로서 물리적 MIMO 시스템을 추정함으로써 복소 공간

에서 통상적으로 모델링 또는 추정되며, 여기에서,

는 MIMO 시스템으로 입력되고 MIMO 채널을 통해 복소 공간

에서

송신 포트를 통해 송신되는 신호 스트림(예를 들어, 심볼)의 입력 벡터 표현이며,

는 복소 공간

에서

수신 포트를 통해 MIMO 시스템의 출력으로서 수신되는 신호 스트림(예를 들어, 심볼)의 출력 또는 측정된 벡터 표현이며,

는 복소 공간

에서 MIMO 시스템의 추정된 채널의 행렬 표현이며,

는 통상적으로 제로 평균(zero mean) 및

의 공분산을 갖는 것으로 상정되는 MIMO 시스템의 복소 공간

에서, 독립적이고 동일하게 분포된 가우시안(Gaussian) 잡음의 벡터 표현이며, 여기에서

는 각 송신 포트에서의 신호 전력을 나타내고,

는

단위 행렬(identity matrix)을 나타낸다.In view of the above,

The transmit port and

A physical MIMO channel for a MIMO system with a receive port is a strictly-linear (SL) system

Lt; RTI ID = 0.0 > MIMO < / RTI &

, Where < RTI ID = 0.0 >

Is input to the MIMO system and is transmitted to the complex space

in

Is an input vector representation of a signal stream (e.g., a symbol) transmitted over a transmit port,

Is a complex space

in

(E.g., a symbol) received as an output of the MIMO system through a receive port,

Is a complex space

≪ / RTI > is the matrix representation of the estimated channel of the MIMO system at &

Lt; RTI ID = 0.0 > zero mean < / RTI >

The complex space of the MIMO system assumed to have the covariance of < RTI ID = 0.0 >

Is a vector representation of independent and identically distributed Gaussian noise,

Represents the signal power at each transmission port,

The

Represents an identity matrix.

In contrast to estimating a MIMO system as a narrow linear system, the present invention provides a system and method for estimating and processing a MIMO system (such as the MIMO system 100 of FIG. 1) as a linear linear (WL) system of light. In contrast to the SL system model, the measurement y depends only on the input signal stream x , and in the WL system model it is assumed that y is dependent not only on the input signal stream x but also on the conjugate of the input signal stream x ^* The exponent * used generally represents a complex conjugate. That is, a linear (WL) system of light is a system that is linear in terms of both the actual input signal stream x and its conjugate signal stream x ^* , as opposed to a narrow linear system that is linear only for the input signal x .

The WL estimation of a MIMO system according to various aspects disclosed herein may provide at least equal or better processing performance than conventional narrow linear processing because a narrow linear system can be understood as a special case of a more general optical linear system . In particular, the WL processing achieves significant performance improvements over conventional narrow-band linear processing in the presence of rotational variant (or inappropriate) input symbols in a MIMO system. However, despite the potential superior performance of WL processing, there remains a problem of estimating the underlying physical MIMO system in the WL framework, or in other words, systematically estimating the channel matrix of the linear optical system.

Various aspects of the present invention describe a systematic approach for implementing a system and method for estimating a MIMO system, such as the MIMO system 100 of FIG. 1, in a WL framework. In addition, the systems and methods disclosed herein can be advantageously applied to model and improve the processing performance of existing MIMO systems.

Figure 2 illustrates an example block diagram of a MIMO system 200 represented in a linear framework of light according to one or more aspects of the present invention. The MIMO system 200 of FIG. 2 can be described as follows.

(1)

(One)

및 입력 신호 벡터 x의 공액

에 기초하여, WL 프레임워크에서의 MIMO 시스템(200)의 측정된 출력값 y가 모델링된다는 것을 알 수 있다.Here, in Equations 1 and 2, compared to the SL model, an additional system matrix

And the conjugation of the input signal vector x

, It can be seen that the measured output value y of the MIMO system 200 in the WL framework is modeled.

송신 포트 및

수신 포트를 갖는 MIMO 시스템에 대한 입력으로서 개수 m 의 학습(본 명세서에서 파일럿이라고도 칭함) 신호 벡터

를 송신함으로써 추정되며, m 은 송신 포트

의 수보다 큰 것으로 선택된다(예를 들어,

). 그러면, 식 (1)은 입력 파일럿 신호 벡터 p의 항으로 이하와 같이 표현될 수 있다:As shown in FIG. 3, in one aspect, the channel matrixes H and G of the WL framework shown in equation (1)

The transmit port and

Learning (also referred to herein as pilot) of the number m as an input to a MIMO system having a receive port,

And m is a transmission port

Gt; (e. G., ≪ / RTI >

). Equation (1) can then be expressed in terms of the input pilot signal vector p as: < RTI ID = 0.0 >

(2)

(2)

Alternatively, it can be expressed equivalently using a matrix as follows:

(3)

(3)

및

은 각각 수신된 신호 행렬, 학습 또는 파일럿 신호 행렬 및 잡음 행렬이다.From here,

And

Are the received signal matrix, the learning or pilot signal matrix, and the noise matrix, respectively.

및

로, 식 (3)은 이하와 같이 된다:Also,

And

(3) < / RTI > is as follows:

(4)

(4)

(또한, 본 명세서에서 증대된 파일럿 행렬이라고도 칭해짐)의 지식으로, WL 시스템 행렬

의 최소 제곱(LS) 추정

는 이하와 같이 달성될 수 있다:Based on the pilot symbol P transmitted by the transmitter and the output Y measured at the receiver

(Also referred to herein as an augmented pilot matrix), knowledge of the WL system matrix

Least-squares (LS) estimation of

Can be achieved as follows:

(5)

(5)

는 증대된 파일럿 행렬

의 의사-역(pseudo-inverse) 파일럿 행렬로서 본 명세서에서 칭해지며, 또한 지수 -1은 본 명세서에서 역행렬을 나타내는 데 일반적으로 사용되며, 지수 H 는 본 명세서에서 일반적으로 표준 행렬 표기법에 따라 행렬의 에르미트(Hermitian) 또는 공액 전치(conjugate transpose)를 나타나는 데 사용된다.From here,

Lt; RTI ID = 0.0 >

Of the pseudo-inverse (pseudo-inverse) becomes now called herein as a pilot matrix, and index of -1 is commonly used to represent an inverse herein, the index H is herein Generally It is used to represent a Hermitian or conjugate transpose of a matrix according to standard matrix notation.

The transmit power limit is assumed to be:

(6)

(6)

는 제한값인 것으로 상정되며,

는 이중선 괄호

의 내용의 프로베니우스 놈(Frobenius norm)을 일반적으로 나타내며, 시스템 추정 에러 E 를 최소화하는, MIMO 시스템에 대한 입력으로서의 최적의 파일럿 행렬 P를 결정하는 것은 최적화와 등가이다.From here,

Is assumed to be a limit value,

Double brace

It is equivalent to optimization to determine the optimal pilot matrix P as an input to the MIMO system, which generally represents the Frobenius norm of the contents of the MIMO system and minimizes the system estimation error E.

에 영향받는

(7)

Affected by

(7)

Using equations (4) and (5), we can find:

(8)

(8)

Thus, the objective function of equation (7) can be expressed as:

(9)

(9)

는 괄호 내의 내용의 행렬 트레이스를 나타내고,

인 것으로 추가적으로 상정된다.In equation (9)

Represents a matrix trace of the contents in parentheses,

.

It can be seen that the optimization of equation (7) is equivalent to:

에 영향받는

(10)

Affected by

(10)

가 이하와 같이 밝혀진다:Using the Lagrange multiplier method, an optimal augmented pilot matrix < RTI ID = 0.0 >

Lt; RTI ID = 0.0 >

(11)

(11)

는 상수이고, 본 명세서에서 사용되는 지수 T 는 표준 행렬 표기법과 같이 일반적으로 행렬의 전치를 나타낸다.From here,

Is a constant, and the exponent T used herein generally refers to the transpose of the matrix, such as the standard matrix notation.

에 대해

를 다시 치환하면 이하를 산출한다:An augmented pilot matrix

About

Lt; RTI ID = 0.0 > of: < / RTI >

(12)

(12)

Using equation (12), equation (11) can be rewritten as:

(13)

(13)

는 일반적으로 행렬의 실수부를 나타낸다.As used herein,

Represents the real part of the matrix.

Expanding equation (13) yields the following:

(14)

(14)

Rewriting equation (14) yields the following:

(15)

(15)

From the above, it can be seen that minimizing the channel estimation error for the MIMO system in the WL framework found in equation (7) can be achieved if the transmitted training symbol matrix P in the MIMO system satisfies:

(16)

(16)

In addition, it is represented as follows:

(17)

(17)

및

는 각각

의 실수 및 허수 지수이며, 식 (16)은 이하와 같이 표현될 수 있다:From here,

And

Respectively

(16) < / RTI > can be expressed as: < RTI ID =

또는

or

(18)

(18)

로 나타내면 이하를 산출한다:

The following is calculated: < RTI ID = 0.0 >

(19)

(19)

From the viewpoint of the power limitation of equation (6), equation (19) is as follows:

(20)

(20)

의 직교 열을 갖는 임의의

행렬

는 식 (9)를 최소화하는 최적 행렬로 고려될 수 있다.Therefore, the same norm

Lt; RTI ID = 0.0 >

procession

Can be considered as an optimal matrix minimizing Equation (9).

In view of the above description, in one aspect, the channel matrices H and G of the MIMO system, such as the MIMO system 100 of FIG. 1, may be represented as linear frameworks of light beginning at step 402 of the process 400 shown in FIG. Lt; / RTI >

의 직교 열을 갖는 실수값 행렬

를 결정한다(스텝 404).The same norm

A real-valued matrix with orthogonal columns of

(Step 404).

를 사용하여, 복소값 파일럿 심볼 행렬

를 결정하며, 여기에서,

및

는 각각

의 상부의 절반 및 하부의 절반이다(스텝 406).

, A complex-valued pilot symbol matrix < RTI ID = 0.0 >

Lt; RTI ID = 0.0 >

And

Respectively

Half of the top and bottom half of the top (step 406).

를 관측한다(스텝 408).Transmits the input pilot symbol matrix P through the MIMO system, and outputs

(Step 408).

를 구축하며, 의사-역 행렬

를 연산하며, 여기에서

는 언제나 구축에 의해 가역적이다(스텝 410).Using the pilot symbol matrix P , an augmented pilot matrix < RTI ID = 0.0 >

, And a pseudo-inverse matrix

Lt; RTI ID = 0.0 >

Is always reversible by construction (step 410).

및 측정된 출력 벡터 Y를 사용하여(그리고, 도 5에 나타낸 바와 같이), 원하는 시스템 행렬 H 및 G를

로서 추정한다(스텝 412). 프로세스(400)는 스텝 414에서 종료될 수 있다.Pseudo-inverse matrix

And the measured output vector Y (and, as shown in Figure 5), the desired system matrices H and G

(Step 412). Process 400 may end at step 414.

으로서의 WL 양식에서 다른 입력 또는 출력에 대해 이제 일반적으로 처리 또는 모델링될 수 있다.The MIMO system uses the estimated H and G determined according to the process 400 of FIG. 4, described above,

Lt; RTI ID = 0.0 > WL, < / RTI >

송신 포트(예를 들어, 포트)에 대해 동등한 전력을 할당하기 위하여, 그리고 예시적인 일 실시예에서 파일럿 심볼의

수가

인 것으로 상정하면, 실수값

행렬

의 모든 엔트리들이 동일한 절대값을 가져야 한다. 이 경우에, 일 실시예에서 실수값

행렬

는 이하와 같이 결정될 수 있다(스텝 402).all

To allocate equal power for a transmit port (e.g., a port), and in an exemplary embodiment,

Number

, The real value

procession

All entries in the table must have the same absolute value. In this case, in one embodiment,

procession

Can be determined as follows (step 402).

의 이진 시퀀스

를 사용하여 깊이

의 이진 트리를 구축하며, 여기에서

는 트리의 각각의 노드의 깊이(또는 레벨)를 나타내며,

는 트리의 각각의 행 또는 레벨에서 특정 노드를 고유하게 식별한다. 이진 트리의 레벨에서의 각각의 부모 노드는, 깊이

트리가 완료될 때까지 도 6(a)에 나타낸 관계를 사용하여 트리의 후속 레벨에서 2개의 자녀 노드로 확장된다. 트리의 최종 레벨 또는 행에서 길이

의

이진 시퀀스가 있을 것이라는 데 유의한다.Length

Binary sequence of

Using depth

To build a binary tree of

(Or level) of each node of the tree,

Identifies a particular node uniquely at each row or level of the tree. Each parent node at the level of the binary tree has a depth

And extends to two child nodes at subsequent levels of the tree using the relationship shown in Figure 6 (a) until the tree is complete. The length in the last level or row of the tree.

of

Note that there will be a binary sequence.

를 트리의 루트 노드(602)로서 설정하면, 루트 노드(602)의 2개의 자녀(604, 606)는

및

를 연산함으로써 도 6(a)에 나타낸 관계를 사용하여 결정되며, 여기에서

는

의 부정(negation)을 나타낸다.A specific example of the 3-level tree is shown in Fig. 6 (b).

Is set as the root node 602 of the tree, the two children 604, 606 of the root node 602

And

Is determined by using the relationship shown in Fig. 6 (a) by calculating

The

And the negation of

로서 취하면, 각각 차례로 608, 610 및 612, 614로 표기되는 2개의 자녀는 관계

및

를 사용하여 다시 연산되며, 여기에서

는 다시

의 부정을 나타낸다.Likewise, each node 604 and 606 may be individually < RTI ID = 0.0 >

The two children, in turn, designated 608, 610, and 612, 614, respectively,

And

Lt; RTI ID = 0.0 >

Again

.

트리가 상술한 바와 같이 완료되면, 행렬

는 트리를 사용하여 일 양태에서 구축된다. 이에 대하여,

의 (n+1)번째 행은

에 대하여

에 의해 구축되며, 전력 연산은 엘리먼트별로 수행된다(예를 들어,

).Once deep

When the tree is completed as described above,

Is constructed in one embodiment using a tree. On the other hand,

The (n + 1) < th >

about

And the power operation is performed on an element-by-element basis (e.g.,

).

는 이하와 같이 결정될 수 있다:Thus, for a specific example of a three-level tree shown in Figure 6 (b), a matrix for a two-input two-output MIMO system

Can be determined as follows: < RTI ID = 0.0 >

는 식 (16)의 조건을 만족하며, 그에 따라 최적의 행렬로 고려될 수 있다. 또한, 모든 송신기 포트에 대한 동등한 전력 제한이 만족되도록, 파일 행렬 P의 모든 엘리먼트는 동일한 전력

를 갖는다.As can be seen from the above, the structured pilot matrix constructed according to the steps described above

Satisfies the condition of equation (16), and can be considered as an optimal matrix accordingly. Also, to ensure that the equivalent power limit for all transmitter ports is satisfied, all elements of the file matrix P are equal in power

.

With the above-described WL characterization of the underlying signal processing system disclosed herein, the WL signal processing method can be applied, thereby achieving a performance improvement over the SL system characterization.

While the embodiments described above use the LS approach to estimate the WL system, other estimation approaches such as, for example, minimum mean square error (MMSE) may be applied.

를 송신함으로써, WL 프레임워크에서 보통의 그리고 공액의 시스템 행렬을 동시에 추정하기 위한 시스템적인 접근법을 설명한다. SL 시스템 추정에 대하여

인 것이 통상적이지만, 다양한 양태에서 본 발명은 WL 시스템 추정에 대하여

를 사용하며,

은 상술한 바와 같이 시스템적으로 결정되는 파일럿 벡터 또는 심볼의 수를 나타낸다.The above-described invention is based on the fact that in the SL framework, a pilot symbol vector (including twice the number) larger than the number used for estimating only the system matrix H

To describe a systematic approach for simultaneously and regularly estimating the conjugate system matrices in the WL framework. About SL system estimation

, But in various aspects the present invention provides for WL system estimation

Lt; / RTI >

Denotes the number of pilot vectors or symbols that are systematically determined as described above.

Based on a larger number (including twice the number) of measurements used to estimate only the normal system matrix H in the SL framework, an estimation method such as LS, MMSE or any other estimation can be performed in a linear framework of light 1) < / RTI > of the normal and conjugate system matrices.

It will be appreciated that one or more aspects of the present invention may be implemented using hardware, software, or a combination thereof. FIG. 7 illustrates a high-level block diagram of an exemplary computing device 700 suitable for implementing one or more aspects of the present invention. Apparatus 700 includes a processor 702 that is communicatively interconnected with various input / output devices 704 and memory 706.

Processor 702 may be any type of processor, such as a general purpose central processing unit ("CPU") or a dedicated microprocessor such as a flush-type microcontroller or digital signal processor ("DSP"). The input / output device 704 may be any peripheral device that operates under the control of the processor 702 and may include a device 700 such as, for example, a network adapter, a data port, and the like, such as a keyboard, a keypad, And may be configured to input data to and output data from the various user interface devices.

The memory 706 may be any type of memory suitable for storing electronic information, including data and instructions executable by the processor 702. The memory 706 may be implemented as one or more of, for example, random access memory (RAM), read only memory (ROM), flash memory, hard disk drive memory, compact disk memory, The device 700 may also include an operating system, a queue manager, a device driver, or one or more network protocols that may be stored in memory 706 and executed by processor 702 in one embodiment. have.

를 통신 채널(130)을 통해 송신기가 (예를 들어, 네트워크를 통해) 송신하게 하는 MIMO 시스템(100)의 송신기(110)와 통신하고 및/또는 이를 제어하도록 구성될 수 있다. 하나 이상의 실시예에서, 프로세서(702)는, 통신 채널(130)을 통해 송신되는 파일럿 심볼 벡터(들)

에 응답하여 수신기(120)에서 생성되는 측정된 출력값

를 (예를 들어, 네트워크를 통해) 수신하는 MIMO 시스템(100)의 수신기(120)와 통신하고 및/또는 이를 제어하도록 구성될 수도 있다. 하나 이상의 실시예에서, 프로세서(702)는 수신기(120)에서 측정되는 출력값 y 및 송신기에 의해 송신되는 파일럿 심볼 벡터(들)

에 기초하여 도 4의 프로세스(400)에 따라 채널 행렬 H 및 G를 결정하거나 추정하도록 구성될 수도 있고, 상세하게 상술한 바와 같이 식 (1)의

과 같은 WL 양식에 따라 WL 프레임워크에서 MIMO 시스템을 모델링하기 위해 추정된 채널 행렬 H 및 G를 사용하도록 구성될 수도 있다.The memory 706 may store instructions that cause the device 700 to function in response to various aspects and the steps described above (e.g., one or more steps of the process 400 of FIG. 4) And non-volatile memory that stores executable instructions and data that can be configured to cause the computer to perform instructions. In one or more embodiments, the processor 702 may be configured to, upon execution of an instruction, generate a pilot symbol vector (s) determined by the processor 702 in accordance with the various aspects (or steps)

May be configured to communicate with and / or control the transmitter 110 of the MIMO system 100 to cause the transmitter to transmit (e.g., via a network) over the communication channel 130. [ In one or more embodiments, processor 702 may be configured to receive pilot symbol vector (s) transmitted via communication channel 130,

The measured output value < RTI ID = 0.0 >

May be configured to communicate with and / or control the receiver 120 of the MIMO system 100 receiving (e.g., via a network) In one or more embodiments, the processor 702 may use the output y measured at the receiver 120 and the pilot symbol vector (s) transmitted by the transmitter,

May be configured to determine or estimate the channel matrices H and G according to the process 400 of FIG. 4 based on Equation (1)

May be configured to use the estimated channel matrices H and G to model the MIMO system in the WL framework according to a WL form such as < RTI ID = 0.0 >

Although the configuration of a particular device is shown in FIG. 7, it will be understood that the invention is not limited to any particular implementation. For example, in other embodiments, the device 700 may be implemented using one or more application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or any other combination of hardware or software.

Although aspects of the disclosure have been described with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is, therefore, to be understood that various modifications may be made to the exemplary embodiments, and that other configurations may be devised without departing from the spirit and scope of the invention.

Claims (15)

The transmit port and

A method for estimating a channel matrix in a multiple-input multiple-output (MIMO) system having a receive port,
Using the processor,

For transmission over the MIMO system using a transmit port

Generating an input symbol matrix P ,

silver

Greater than -
remind

In response to the transmission of the input symbol matrix P via the MIMO system using the receive port

Determining an output symbol matrix Y ,
Based on the input symbol matrix P

A pseudo-inverse matrix

,
The pseudo-inverse matrix

And estimating a first channel matrix H and a second channel matrix G for the MIMO system using the output symbol matrix Y
Channel matrix estimation method.
The method according to claim 1,
The first channel matrix H for the MIMO system and the second channel matrix G for

Lt; RTI ID = 0.0 >
Channel matrix estimation method.
3. The method of claim 2,
The operation of the MIMO system

Using an estimated first channel matrix H and an estimated second channel matrix G for modeling as a channel matrix H ,

Through the MIMO system,

An input vector representing an input signal stream to be transmitted via a transmission port,

Is a conjugate representation of the input vector,

Is a vector representation of independent and identically distributed Gaussian noise of the MIMO system,

Gt; MIMO < / RTI >

The output vector representation of the output signal stream received at the receive port.
Channel matrix estimation method.
The method according to claim 1,
Having the same orthogonal column of the same norm

Real-valued matrix

,
To determine the input symbol matrix P

RTI ID = 0.0 >
Channel matrix estimation method.
The method according to claim 1,
Using the input symbol matrix P , an augmented pilot matrix < RTI ID = 0.0 >

Step -

Is a conjugate matrix of the input symbol matrix P ,

And the pseudo-inverse matrix

≪ / RTI >

The

Hermitian < / RTI > matrix of < RTI ID =

Lt; RTI ID = 0.0 >
Channel matrix estimation method.
5. The method of claim 4,
The real value matrix

Wherein:
depth

Further comprising constructing a multi-node binary tree of < RTI ID = 0.0 >
At a particular level of the multi-node binary tree, at least one parent node

Relationship

And

Lt; / RTI > is extended to two child nodes at a subsequent level of the multi-node binary tree,

The

And < RTI ID = 0.0 >

Represents a particular level of the tree,

Lt; / RTI > identifies one or more nodes at a particular level of the tree
Channel matrix estimation method.
A system for estimating a channel matrix,

A transmitter having a transmit port,

A receiver having a receive port, the transmitter and the receiver being communicatively coupled via a communications channel;
A processor, comprising:
remind

For transmission over the communication channel by the transmitter via a transmission port

Generates an input symbol matrix P and -

silver

Greater than -
In response to the transmission of the input symbol matrix P over the communication channel,

Received on the receive port

Determines an output symbol matrix Y ,
Based on the input symbol matrix P

Pseudo-inverse matrix

Lt; / RTI >
The pseudo-inverse matrix

And estimating a first channel matrix H and a second channel matrix G for the communication channel using the output symbol matrix Y
Channel matrix estimation system.
8. The method of claim 7,
The processor comprising:

To estimate the first channel matrix H and the second channel matrix G using < RTI ID = 0.0 >
Channel matrix estimation system.
9. The method of claim 8,
The processor comprising:
The operation of the transmitter, the receiver and the communication channel

Lt; RTI ID = 0.0 > H < / RTI > and the estimated second channel matrix G for modeling as a second channel matrix H ,

Via the communication channel,

An input vector representing an input signal stream to be transmitted via a transmission port,

Is a conjugate representation of the input vector,

Is a vector representation of independent and identically distributed Gaussian noise due to the communication channel,

Via the communication channel,

The output vector representation of the output signal stream received at the receive port.
Channel matrix estimation system.
8. The method of claim 7,
The processor comprising:
Having the same orthomorphic column

Real-valued matrix

Lt; / RTI >
To determine the input symbol matrix P

Is further configured to use
Channel matrix estimation system.
8. The method of claim 7,
The processor comprising:
Using the input symbol matrix P , an augmented pilot matrix < RTI ID = 0.0 >

And -

Is a conjugate matrix of the input symbol matrix P ,

And the pseudo-inverse matrix

, ≪ / RTI >
remind

The

, ≪ / RTI >

Is reversible
Channel matrix estimation system.
11. The method of claim 10,
The processor comprising:
depth

Node binary tree, the real-valued matrix < RTI ID = 0.0 >

, ≪ / RTI >
At a particular level of the multi-node binary tree, at least one parent node

Relationship

And

Lt; / RTI > is extended to two child nodes at a subsequent level of the multi-node binary tree,

The

And

Represents a particular level of the tree,

Lt; / RTI > identifies one or more nodes at a particular level of the tree
Channel matrix estimation system.
8. The method of claim 7,
remind

The transmission port and the above-

The receiving port includes an antenna, and the communication channel includes a wireless medium
Channel matrix estimation system.
8. The method of claim 7,
The communication channel is a wired communication channel
Channel matrix estimation system.
8. The method of claim 7,
Wherein the communication channel comprises an optical communication channel
Channel matrix estimation system.

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