KR101459049B1 - Reception apparatus for multiple carrier transmission system and channel estimation method in the same - Google Patents

Abstract

A receiving apparatus of a multi-carrier transmission system and a channel estimation method in the apparatus are disclosed.
The FFT unit of the receiving apparatus performs FFT on the multicarrier signal transmitted from the transmitting apparatus and outputs the signal as a signal in the frequency domain. The weight controller calculates weights by performing time domain channel synthesis and frequency domain channel synthesis on a signal output from the FFT unit, and performs time domain channel synthesis and frequency domain channel synthesis repeatedly in a plurality of stages To generate a final weight, and applies the final weight generated to the signal output from the FFT unit and outputs the final weight. The demodulator demodulates and decodes the signal output by the weight controller to recover the final signal.

Description

[0001] The present invention relates to a receiving apparatus for a multi-carrier transmission system and a channel estimation method therefor. More particularly,

The present invention relates to a receiving apparatus of a multicarrier transmission system and a channel estimation method in the apparatus.

All the multiple access schemes employing OFDM (Orthogonal Frequency Division Multiplexing) have a multi-carrier form using IFFT (Inverse Fast Fourier Transform) as the last signal processing method of the transmitting apparatus. At this time, the sub-carriers of the entire band have independent sub-channels.

The signal transmitted from the transmitting apparatus is received through the antenna of the receiving apparatus. When the receiving structure of the multiple antennas is used, different channel effects are experienced for each branch.

In this way, bit error rate (BER) performance deterioration occurs due to the characteristics of the frequency selective channel to be experienced through each channel. In particular, since the coherent bandwidth is narrow due to the characteristics of systems using multi- The BER performance degradation is severe.

Therefore, a scheme for overcoming the BER performance degradation phenomenon in a transmission system using multicarrier is required.

Patent Document 1: Published Japanese Patent Application No. 10-2008-0067398 (published on July 21, 2008) Patent Document 2: Published Patent Application No. 10-2010-0080667 (Published on July 12, 2010) Patent Document 3: Registration Patent No. 10-1160526 (registered on June 21, 2012)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a receiving apparatus for a multicarrier transmission system and a channel estimation method therefor, which can prevent degradation of BER performance due to characteristics of a fading channel in a multi-carrier transmission system.

According to one aspect of the present invention,

There is provided a receiving apparatus for a multi-carrier transmission system, comprising: a Fast Fourier Transform (FFT) unit for performing FFT on a multicarrier signal transmitted from a transmitting apparatus and outputting the signal as a signal in a frequency domain; Domain channel synthesis and frequency domain channel synthesis for a signal output from the FFT unit to perform weighted channel estimation and time domain channel combining and frequency domain channel combining repeatedly in a plurality of stages, A weight controller for generating a weight and applying the final weight generated to the signal output from the FFT unit and outputting the weight; And a demodulator that demodulates and decodes the signal output from the weight controller and reconstructs the signal as a final signal.

Here, the weight controller may further include: a channel estimator for performing channel estimation using a pilot symbol subcarrier signal with respect to a signal output from the FFT unit and outputting a weight corresponding to a channel estimation value; A time domain synthesizer for repeatedly performing a channel estimation operation in the channel estimator, for synthesizing a weight output from the channel estimator for each iteration, and for outputting a time synthesized weight; A frequency synthesizer for performing interpolation between weights of adjacent subcarriers using the time synthesized weight output from the time domain synthesizer and performing synthesis between the weights interpolated and the weights before the interpolation operation, An area synthesizer; And a multi-stage iterative execution unit for controlling the weight calculation process through the channel estimation of one stage performed by the channel estimation unit, the time domain synthesis unit, and the frequency domain synthesis unit to be repeatedly performed as many times as the preset number of iterations.

In addition, the channel estimator performs channel estimation using a minimum mean square error (MMSE) -based channel estimation algorithm.

In addition, the time domain combining unit performs time domain combining considering a coherent time of the multi-carrier transmission system.

In addition, the channel estimator performs channel estimation using a pilot symbol of a signal for each subcarrier, and the time domain combiner performs time domain synthesis on a channel estimated weight for each pilot symbol.

In addition, the frequency domain combining unit performs frequency domain combining considering the coherent frequency of the multi-carrier transmission system.

The multi-stage iterative execution unit controls the weights outputted from the frequency domain combining unit in the previous stage to be fed back to the channel estimating unit in the next stage when the weight calculating process is repeated by the number of iterations.

The weight controller synthesizes the channel compensation values using the weights of the same subcarrier of the repetition number of times output from the frequency domain combining unit after repeating the repetition times by the multi-stage repetition performing unit and outputting A stage synthesizer; And a final weight calculating unit for calculating the final weight by combining the weights of the repeated number of stages output from the stage combining unit so as to have a maximum ratio for each subcarrier and applying the final weight to a signal output from the FFT unit.

The time domain combining unit may further include: a weight storing unit for storing a weight for each subcarrier outputted from the channel estimating unit; A correlation time obtaining unit for obtaining a correlation time of the multi-carrier transmission system; A time repeating unit for feeding back the weights of the subcarriers stored in the weight storage unit to the channel estimator in consideration of the correlation time acquired by the correlation time acquisition unit and controlling the channel estimation to be repeated by the number of pilot symbols; A time-side combining unit which is repeatedly performed by the time repetition performing unit and temporally combines the weights stored in the weight storing unit to output weights synthesized on a time-by-subcarrier basis; And a time synthesis weight storage unit for storing a time synthesized weight for each subcarrier outputted by the time-side synthesis unit.

In addition, the time-side combining unit performs combining so that the weights calculated by MMSE over the entire pilot symbols are maximized.

The frequency domain combining unit may further include: a correlation bandwidth obtaining unit that obtains a correlation bandwidth of the multi-carrier transmission system; A frequency interpolation operation unit for performing interpolation between weights of adjacent subcarriers using the time synthesized weight outputted from the time domain synthesizer in consideration of a correlation bandwidth obtained by the correlation bandwidth acquisition unit; A frequency-side combiner for combining the weights interpolated by the frequency interpolation calculator and the weights before the interpolation operation to output a frequency synthesized weight for each sub-carrier; And a weight storing unit for each stage for storing the frequency synthesized weight for each subcarrier outputted from the frequency side combining unit for each stage.

The frequency interpolation operation unit performs an interpolation operation considering the weights of adjacent subcarriers within a correlation bandwidth range with respect to a specific subcarrier.

Further, the frequency-side combining unit may perform a maximum ratio combining or a fixed ratio combining according to a channel state to calculate a frequency synthesized weight.

According to another aspect of the present invention,

A method for performing channel estimation using a three-dimensional weight combining method in a receiving apparatus of a multi-carrier transmission system, comprising: receiving a sub-carrier signal transmitted from a transmitting apparatus; Calculating a weight using time domain synthesis and frequency domain synthesis using the subcarrier signal, synthesizing weights using the correlation of the calculated weights with respect to procedural adjacencies, and outputting the synthesized weights to a final weight; And applying the final weight to the subcarrier signal to restore the original signal.

Here, the step of outputting to the final weight may include performing time domain synthesis using a pilot symbol of the subcarrier signal in consideration of a correlation time of the multi-carrier transmission system; Performing frequency domain synthesis through mutual interpolation between adjacent weights in consideration of a correlation bandwidth of the multi-carrier transmission system, the time synthesized weights calculated through the time domain synthesis; Performing the time domain synthesis and performing the frequency domain synthesis on the basis of a predetermined number of iterations for a predetermined number of iterations, And synthesizing the weights for each stage by the number of repetitions and calculating a final weight.

Also, in performing the time domain combining, the channel estimation for the subcarrier signal is repeatedly performed by the number of pilot symbols.

The performing the frequency domain combining may further include performing interpolation between weights of adjacent subcarriers using the time synthesized weight considering the correlation bandwidth; And outputting a frequency-synthesized weight for each subcarrier by performing synthesis between the interpolation-calculated weights and the weights before the interpolation operation.

According to the present invention, adverse effects on existing BER performance can be prevented.

In addition, it is possible to accurately process a large amount of data with a minimum loss, thereby satisfying the requirements of users pursuing quality of service.

1 is a diagram illustrating a frame structure of a signal applied in a multi-carrier transmission system according to an embodiment of the present invention.
2 is a block diagram illustrating a configuration of a reception apparatus of a multi-carrier transmission system according to an embodiment of the present invention.
3 is a diagram showing a configuration of the weight controller shown in Fig.
4 is a block diagram of the configuration of the time domain combiner shown in FIG.
5 is a block diagram of the frequency domain combiner shown in FIG.
6 is a flowchart of a channel estimation method in a receiving apparatus of a multi-carrier transmission system according to an embodiment of the present invention.
FIG. 7 is a diagram illustrating a concept in which a reception apparatus of a multi-carrier transmission system according to an embodiment of the present invention repeatedly performs synthesis of a time domain and synthesis of a frequency domain over a plurality of stages to calculate a final weight.
FIG. 8 is a block diagram of a receiving apparatus of a multi-carrier transmission system according to another embodiment of the present invention.

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. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise. Also, the terms " part, "" module," and " module ", etc. in the specification mean a unit for processing at least one function or operation and may be implemented by hardware or software or a combination of hardware and software have.

1 is a diagram illustrating a frame structure of a signal applied in a multi-carrier transmission system according to an embodiment of the present invention.

개의 심볼로 구성되고, 이들 중에서 앞 부분의

개의 심볼을 파일롯(pilot) 심볼로써 하나의 블록으로 전체 프레임 구조상에 위치하고, 나머지

개의 심볼이 데이터 심볼로써 구성된다. 그리고, 다중 반송파 전송 시스템은 전체

개의 부반송파를 사용하여 신호를 전송한다.Referring to FIG. 1,

Symbols, and of these,

Symbols are placed on the entire frame structure as one block with pilot symbols, and the remaining

Symbols are composed of data symbols. In addition, the multi-carrier transmission system

Lt; / RTI > subcarriers.

2 is a block diagram illustrating a configuration of a reception apparatus of a multi-carrier transmission system according to an embodiment of the present invention.

2, a receiving apparatus according to an embodiment of the present invention includes an antenna 100, an A / D converter 110, a cyclic prefix (CP) remover 120, an FFT A Fourier transformer 130, a demapper 140, a memory 150, a weight controller 200, a multiplier 160, and a demodulator 170.

Antenna 100 receives a multicarrier signal transmitted from a transmitting device (not shown). The antenna 100 may be a single input single output (SISO), a multiple input multiple output (MIMO), a single input multiple output (SIMO), a multiple input single output (MISO) Structure. In the embodiment of the present invention, SISO structure is used for convenience of explanation.

The A / D converter 120 converts a signal received from the antenna 100 into a digital signal and outputs the digital signal.

The CP remover 120 removes the CP from the signal output from the A / D converter 120 and outputs the CP.

The FFT unit 130 performs an FFT on the signal output from the CP remover 120 to convert the signal into a frequency domain signal and output the signal.

The demapper 140 demaps the signal output from the FFT unit 130 for each subcarrier and outputs the demapper.

개의 부반송파 신호가 저장된다.The memory 150 receives and stores a signal for each subcarrier outputted from the demapper 140. Therefore, in the memory 150,

Carrier signals are stored.

개의 부반송파 신호를 사용하여 시간 영역 채널 및 주파수 영역 채널 합성에 의한 채널 추정에 의해 웨이트를 생성하여 출력한다. 이 때, 웨이트 제어기(200)는 메모리(150)에 저장되어 있는

개의 부반송파 신호 중에서 파일롯 심볼의 정보를 이용하여 채널 추정을 수행하며, 시간 영역 채널 및 주파수 영역 채널 합성에 의한 채널 추청을 통해 웨이트를 산출하는 것을 복수의 스테이지 형태로 반복적으로 수행하여 웨이트를 생성한다. 이러한 반복적 수행에 의한 웨이트 생성에 의해 수신 장치의 BER 성능이 향상될 수 있다.The weight controller 200 includes a memory controller 150,

And generates and outputs a weight by channel estimation using a time domain channel and a frequency domain channel synthesis. At this time, the weight controller 200 controls the weight

The weight is generated by performing channel estimation using information of a pilot symbol among a plurality of subcarrier signals and calculating weights through channel estimation by combining a time domain channel and a frequency domain channel by repeatedly performing a plurality of stages. The BER performance of the receiving apparatus can be improved by generating the weight by the iterative performance.

On the other hand, due to the characteristics of the fading channel in channel estimation, one channel has a correlation with respect to the adjacent frequency and time. Accordingly, the weight controller 200 synthesizes the new weight using the correlation of the adjacent time and frequency and the procedural adjacency (repeatability).

Also, it is desirable to use a channel estimation technique that can effectively compensate a channel for overcoming BER performance degradation. In particular, in order to consider an antenna having a multi-antenna structure, it is necessary to apply a frequency domain equalizer (FDE) scheme capable of considering channels individually. Therefore, in the embodiment of the present invention, the weight controller 200 performs channel estimation using an MMSE (Minimum Mean Square Error) -based channel estimation algorithm for calculating an effective weight. Of course, the weight controller 200 may also use a different type of channel estimation algorithm to combine the new weights using the correlation of adjacent time, frequency, and procedural proximity.

The multiplier 160 applies the weight generated by the weight controller 200 to the signal for each subcarrier stored in the memory 150 and outputs the weight.

The demodulator 170 demodulates and decodes the signal output from the adder 170 and restores the signal as a final signal.

3 is a diagram showing a configuration of the weight controller 200 shown in FIG.

3, the weight controller 200 includes a channel estimator 210, a time domain synthesizer 220, a frequency domain synthesizer 230, a multi-stage iterator 240, a stage synthesizer 250 and a final weight calculating unit 260. [

The channel estimation unit 210 performs channel estimation on the basis of the MMSE operation using the subcarrier signals of the pilot symbols stored in the memory 150, and outputs the channel estimation values. The channel estimation value at this time is output as a weight for each pilot symbol for each subcarrier.

회만큼 채널 추정이 반복 수행하도록 하고, 반복 수행 때마다 출력되는 파일롯 심볼별 웨이트를 시간적으로 합성하여

개의 부반송파별로 시간 합성된 웨이트를 출력한다.The time domain combining unit 220 feeds back the weight for each subcarrier outputted from the channel estimating unit 210 to the channel estimating unit 210 in consideration of the coherent time of the multi-carrier transmission system,

The channel estimation is repeatedly performed as many times as possible, and the weights of the pilot symbols output every repetition are synthesized temporally

Outputs a weight synthesized with time for each subcarrier.

개의 부반송파별로 주파수 합성된 웨이트를 출력한다.The frequency domain combiner 230 performs interpolation between weights of adjacent subcarriers using the time synthesized weight outputted from the time domain combiner 220 considering the coherent frequency of the multicarrier transmission system, Synthesis is performed between the interpolation-calculated weights and the weights before the interpolation operation

And outputs a frequency synthesized weight for each subcarrier.

The multistage repetition performing unit 240 performs a weight calculating process through channel estimation of one stage performed by the channel estimating unit 210, the time domain combining unit 220 and the frequency domain combining unit 230 And the weight of the stage output from the frequency domain combiner 230 is fed back to the channel estimator 210 so as to be used in the next stage.

The stage combining unit 250 repeats P times by the multi-stage iterating unit 240 and synthesizes the channel compensation values using the weights of the same subcarriers of the P stages from the frequency domain combining unit 230 and outputs them.

The final weight calculator 260 calculates the final weights by combining the weights of the P stages output from the stage combiner 250 so as to have the maximum ratio for each subcarrier and outputs the final weights to the multiplier 170 so as to be compensated for the data portion of each subcarrier do.

4 is a block diagram of the time domain combiner 220 shown in FIG.

4, the time-domain synthesis unit 220 includes a weight storage unit 221, a correlation time acquisition unit 223, a time repetition performing unit 225, a time-side synthesis unit 227, And a storage unit 229.

The weight storage unit 221 stores a weight for each subcarrier outputted from the channel estimation unit 210. [

The correlation time acquisition unit 223 acquires the correlation time of the multi-carrier transmission system. This correlation time is already well known to those skilled in the art and is assumed to be preset by the system user.

회만큼 채널 추정이 반복 수행되도록 제어한다.The time repetition performing unit 225 feeds back the weight for each subcarrier stored in the weight storing unit 221 to the channel estimating unit 210 in consideration of the correlation time acquired by the correlation time acquiring unit 223, Number, ie

So that channel estimation is repeatedly performed as many times as possible.

개의 부반송파별로 시간 합성된 웨이트를 출력한다.The time-side combiner 227 is repeatedly performed by the time repetition performing unit 225 to temporally combine the weights stored in the weight storage unit 221

Outputs a weight synthesized with time for each subcarrier.

개의 파일롯 심볼에 걸쳐 각각 MMSE 연산된 웨이트를 최대비가 되도록 합성을 수행한다.Here, the time-side combiner 227 is a

The synthesized symbols are weighted so that the weights of the MMSE computed over the pilot symbols are maximized.

The temporal synthesis weight storage unit 229 stores a time synthesized weight for each subcarrier outputted by the temporal synthesis unit 227. [

5 is a block diagram of the frequency domain combiner 230 shown in FIG.

5, the frequency domain combiner 230 includes a correlation bandwidth obtaining unit 231, a frequency interpolation calculating unit 233, a frequency side combining unit 235, and a stage weight storing unit 237 .

The correlation bandwidth obtaining unit 231 obtains the correlation bandwidth of the multi-carrier transmission system. This correlated bandwidth is assumed to be preset by the system user, as is well known to those skilled in the art.

The frequency interpolation calculator 233 performs interpolation between weights of adjacent subcarriers using the time synthesized weight outputted from the time domain synthesizer 220 in consideration of the correlation bandwidth obtained by the correlation bandwidth acquiring unit 231 .

Here, the frequency interpolation calculator 233 performs an interpolation operation considering the weights of adjacent subcarriers in the range of the correlation bandwidth around the n-th subcarrier. At this time, the number of adjacent subcarriers can be set variously according to system characteristics.

개의 부반송파별로 주파수 합성된 웨이트를 출력한다.The frequency-side combiner 235 performs synthesis between the weights interpolated by the frequency interpolation calculator 233 and the weights before the interpolation operation

And outputs a frequency synthesized weight for each subcarrier.

At this time, the frequency-side combiner 235 performs the maximum ratio combining or the fixed ratio combining according to the channel state to calculate and output the frequency synthesized weight. Since the frequency-side combining unit 235 performs the maximum ratio combining or the fixed ratio combining according to the channel state, it is possible to prevent the repetitive accumulation of the noise components and to obtain the frequency diversity effect because more subcarrier information is considered. .

The weight storing unit 237 stores the weight synthesized by the frequency synthesizer 235 for each stage.

Hereinafter, a channel estimation method in a receiving apparatus of a multi-carrier transmission system according to an embodiment of the present invention will be described with reference to FIG.

개의 부반송파 신호를 수신한다(S100).First, the weight controller 200 of the receiving apparatus stores the weight data in the memory 150

(S100).

Thereafter, the weight controller 200 performs channel estimation using the pilot symbols of the subcarrier signals in consideration of the correlation time of the multi-carrier transmission system (S110).

개수만큼 반복 수행되었는지를 판단하고(S120), 만약 파일롯 심볼의 개수만큼 반복 수행되지 않았으면 상기 단계(S110)를 반복 수행하여 파일롯 심볼별 부반송파별 웨이트를 산출한다.The number of such channel estimates depends on the number of pilot symbols,

(S120). If the number of iterations is not equal to the number of pilot symbols, the step S110 is repeated to calculate a weight for each subcarrier for each pilot symbol.

If it is determined in step S120 that the number of the pilot symbols has been repeatedly calculated, the calculated weights are temporally synthesized to calculate weights synthesized in time (S130).

Thereafter, an interpolation operation is performed on the weights synthesized in the step S130 in consideration of the correlation bandwidth (S140).

Then, frequency synthesis is performed using interpolation-calculated weights and weights before the interpolation operation to calculate frequency synthesized weights (S150).

It is determined whether the weight calculation in which the synthesis of the time and frequency domains has been performed is repeated for the total number of stages, that is, P times (S160).

If it is not repeatedly performed for P times, the steps S110, S120, S130, S140, and S150 are controlled to be repeated for P times. At this time, the weight calculated in the step S150 is fed back with the channel estimation weight of the next stage (S170).

However, if it is repeated P times in step S160, weights of the subcarriers for each stage are combined to calculate final weights (S180).

Referring to FIG. 7, the concept that the synthesis of the time domain and the synthesis of the frequency domain are repeated over a plurality of stages to calculate the final weight can be found in detail.

As described above, a three-dimensional (3-Dimension) channel estimation for performing channel estimation by repeatedly calculating one stage, which is channel-estimated in time and frequency domain, over multiple stages is performed on all pilot symbols, It is possible to prevent adverse effects on performance.

The final weights calculated by the above channel estimation are compensated for the data output from the memory 150. [

In the above description, it is assumed that the antenna structure is SISO. However, the technical scope of the present invention is not limited to the above. The case of the MIMO antenna structure is as shown in FIG. The structure shown in FIG. 8 has a structure similar to that shown in FIG. 2, and the structure shown in FIG. 2 is different from the structure shown in FIG. 2 in that the weight controller 200 includes a plurality of memories 150-1, 150-2, The final weight is applied to each of the multipliers 160-1, 160-2, ..., and 160-n, and each multiplier 160-1, 160-2, ..., And an adder 180 for additionally adding the signals output from the demodulator 170 to the demodulator 170.

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 (17)

A receiving apparatus of a multi-carrier transmission system,
An FFT (Fast Fourier Transform) unit for performing FFT on a multicarrier signal transmitted from a transmitter and outputting the signal as a signal in a frequency domain;
Domain channel synthesis and frequency domain channel synthesis for a signal output from the FFT unit to perform weighted channel estimation and time domain channel combining and frequency domain channel combining repeatedly in a plurality of stages, A weight controller for generating a weight and applying the final weight generated to the signal output from the FFT unit and outputting the weight; And
And a demodulator that demodulates and decodes a signal output from the weight controller to recover the signal as a final signal,
The weight controller synthesizes channel compensation values using the weights of the same subcarrier of the plurality of stages and synthesizes the weights of the plurality of stages so as to have a maximum ratio to calculate the final weight
. The method according to claim 1,
The weight controller includes:
A channel estimator for performing channel estimation on a signal output from the FFT unit using a subcarrier signal of a pilot symbol and outputting a weight corresponding to a channel estimation value;
A time domain synthesizer for repeatedly performing a channel estimation operation in the channel estimator, for synthesizing a weight output from the channel estimator for each iteration, and for outputting a time synthesized weight;
A frequency synthesizer for performing interpolation between weights of adjacent subcarriers using the time synthesized weight output from the time domain synthesizer and performing synthesis between the weights interpolated and the weights before the interpolation operation, An area synthesizer; And
A multi-stage repetition unit for repeatedly performing a weight calculation process through channel estimation of one stage performed by the channel estimation unit, the time domain synthesis unit, and the frequency domain synthesis unit,
. 3. The method of claim 2,
Wherein the channel estimator performs channel estimation using a minimum mean square error (MMSE) -based channel estimation algorithm. The method of claim 3,
Wherein the time domain combining unit performs time domain combining considering a coherent time of the multi-carrier transmission system. 5. The method of claim 4,
Wherein the channel estimator performs channel estimation using a pilot symbol of a signal for each subcarrier,
The time domain combining unit performs time domain combining on the channel estimated weight for each pilot symbol
. The method of claim 3,
Wherein the frequency domain combining unit performs frequency domain combining considering a coherent frequency of the multi-carrier transmission system. The method of claim 3,
Wherein the multi-stage iterative execution unit controls the weights outputted from the frequency domain combining unit in the previous stage to be feedback-processed to the channel estimating unit in the next stage when the weight calculating process is repeated by the number of iterations. 3. The method of claim 2,
The weight controller includes:
A stage combining unit for combining and outputting channel compensation values using the weights of the same subcarrier of the repetition number of stages output from the frequency domain combining unit after repeating the number of iterations by the multi-stage iterating unit; And
Calculating a final weight by combining the weights of the repeated number of stages output from the stage combining unit so as to have a maximum ratio for each subcarrier, and applying the final weight to a signal output from the FFT unit;
Further comprising: 6. The method of claim 5,
Wherein the time-
A weight storage unit for storing a weight for each subcarrier outputted from the channel estimator;
A correlation time obtaining unit for obtaining a correlation time of the multi-carrier transmission system;
A time repeating unit for feeding back the weights of the subcarriers stored in the weight storage unit to the channel estimator in consideration of the correlation time acquired by the correlation time acquisition unit and controlling the channel estimation to be repeated by the number of pilot symbols;
A time-side combining unit which is repeatedly performed by the time repetition performing unit and temporally combines the weights stored in the weight storing unit to output weights synthesized on a time-by-subcarrier basis; And
And a time synthesis weight storage unit for storing a time synthesized weight for each subcarrier outputted by the time-
. 10. The method of claim 9,
Wherein the time-side combining unit performs combining so that the weights calculated by MMSE over the entire pilot symbols are maximized. The method according to claim 6,
Wherein the frequency domain combiner comprises:
A correlation bandwidth acquiring unit for acquiring a correlation bandwidth of the multi-carrier transmission system;
A frequency interpolation operation unit for performing interpolation between weights of adjacent subcarriers using the time synthesized weight outputted from the time domain synthesizer in consideration of a correlation bandwidth obtained by the correlation bandwidth acquisition unit;
A frequency-side combiner for combining the weights interpolated by the frequency interpolation calculator and the weights before the interpolation operation to output a frequency synthesized weight for each sub-carrier; And
A weight storing unit for each stage for storing the frequency synthesized weight for each subcarrier outputted from the frequency side combining unit for each stage,
. 12. The method of claim 11,
Wherein the frequency interpolation operation unit performs an interpolation operation considering the weights of adjacent subcarriers within a correlation bandwidth range with respect to a specific subcarrier. 12. The method of claim 11,
Wherein the frequency-side combiner performs a maximum ratio combining or a fixed ratio combining according to a channel state to calculate a frequency synthesized weight. A method for performing channel estimation using a three-dimensional weight synthesis in a receiver of a multi-carrier transmission system,
Receiving a subcarrier signal transmitted from a transmitting apparatus;
Calculating a weight using the time domain channel synthesis and the frequency domain channel synthesis using the subcarrier signal, synthesizing weights using the correlation of the calculated weights with respect to the procedural adjacency, and outputting the weight to the final weight;
And applying the final weight to the subcarrier signal to restore the original signal,
In the step of outputting to the final weight,
Domain channel synthesis and frequency domain channel synthesis are repeatedly performed in a plurality of stages to generate final weights, and a channel compensation value is synthesized using weights of the same sub-carriers of a plurality of stages, and weights of the plurality of stages So that the final weight is calculated
Channel estimation method. 15. The method of claim 14,
Wherein the step of outputting to the final weight comprises:
Performing time domain combining using the pilot symbols of the subcarrier signals in consideration of a correlation time of the multi-carrier transmission system;
Performing frequency domain synthesis through mutual interpolation between adjacent weights in consideration of a correlation bandwidth of the multi-carrier transmission system, the time synthesized weights calculated through the time domain synthesis;
Performing the time domain synthesis and performing the frequency domain synthesis on the basis of a predetermined number of iterations for a predetermined number of iterations, And
Synthesizing the weights for each stage by the number of repetitions and calculating a final weight
/ RTI > 16. The method of claim 15,
Wherein the channel estimation for the subcarrier signal is repeated for the number of pilot symbols. 17. The method of claim 16,
Wherein performing the frequency domain synthesis comprises:
Performing interpolation between weights of adjacent subcarriers using the weight synthesized in consideration of the correlation bandwidth; And
Synthesizing between the interpolation-calculated weights and the weights before the interpolation operation, and outputting the frequency-synthesized weights for each sub-carrier
/ RTI >

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