KR100821123B1 - Signal amplitude and phase predistortion device and method, and orthogonal frequency division multiplexing transmission system and method using same - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a signal amplitude and phase predistortion device and a method thereof, and an orthogonal frequency division multiplexing transmission system using the same.

2. The technical problem to be solved by the invention

SUMMARY OF THE INVENTION An object of the present invention is to provide a signal magnitude and phase predistortion apparatus and method for distorting each constellation point in magnitude and phase according to contributions between orthogonal frequency division multiplexing (OFDM) symbols.

In addition, the present invention uses a signal size and a phase predistortion technique to reduce the computational complexity of the system in a wireless communication and broadcasting system using an Orthogonal Frequency Division Multiplexing (OFDM) method while reducing the peak power to average power ratio (PAPR). It is another object to provide an orthogonal frequency division multiplexing transmission system and a method for effectively reducing the same.

3. Summary of Solution to Invention

와 위상

으로 왜곡시키는 신호 크기와 위상 선왜곡 알고리즘을 통해, 상기 원래의 OFDM 심볼의 첨두신호(peak signal)를 줄여 송신하는 것을 특징으로 함.The present invention converts serially input serial data into N (N is a natural number) parallel data, and creates one OFDM symbol modulated and inverse fast Fourier transform (IFFT) using the converted parallel data. In an orthogonal frequency division multiplex (OFDM) transmission system, which takes a transient sampling to make the original OFDM symbol similar to a continuous OFDM symbol, an inverse fast Fourier transform (IFTT) multicarrier and the multiple carriers are combined. Contributions between orthogonal frequency division multiplexing (OFDM) symbols are measured, and the signal magnitude and phase coefficient to be increased for each carrier signal based on the measured contribution are obtained, and the obtained signal magnitude and phase coefficient are used. Corresponding signal size for each constellation point

And phase

By reducing the peak signal (peak signal) of the original OFDM symbol through a signal magnitude and a phase predistortion algorithm to be distorted.

4. Important uses of the invention

The present invention is used in orthogonal frequency division multiplexing (OFDM) transmission systems.

Description

Amplitude and Phase Predistortion Apparatus and Method, and OFDM Transmission System and Method using That

1A is a block diagram of an exemplary embodiment of a signal amplitude and phase line distortion device and an orthogonal frequency division multiplexing transmission system using the same;

Figure 1b is a detailed configuration diagram of an embodiment of the signal amplitude and phase line distortion device according to the present invention,

2 is a constellation diagram showing signal magnitude and phase line distortion of some carriers for QPSK, N = 128 obtained in the signal magnitude and phase line distortion device according to the present invention;

3 is a view of converting the constellation of FIG. 2 into OFDM symbols;

4 is a diagram illustrating a correlation between each carrier signal and OFDM symbols formed by gathering the carriers according to the present invention;

에서 수정된 캐리어 개수에 따른 첨두전력 대 평균전력 비(PAPR)를 나타낸 도면, 5 shows the cumulative density function (CCDF)

Showing peak-to-average power ratio (PAPR) according to the number of carriers modified in

FIG. 6 is a diagram illustrating a change in the cumulative density function (CCDF) of an OFDM symbol using a signal size predistortion technique (SAP) and a signal size and phase predistortion technique (SAPP).

* Explanation of symbols for the main parts of the drawings

11: Serial / parallel converter 12: Modulator (M-QAM)

13: N point inverse fast Fourier transform unit (IFFT) 14: bottle / serial transform unit

15: transient sampling unit

16: Signal magnitude and phase predistortion device

The present invention relates to a signal amplitude and phase predistortion device, a method thereof, and an orthogonal frequency division multiplexing (OFDM) transmission system using the same, and more particularly, to signal amplitude. And wireless communication such as Digital Audio Broadcasting (DAB) -T, Digital Video Broadcasting (DVB) -T, Asymmetric Digital Subscriber Line (ADSL), and Wireless Local Area Network (WLAN) using OFDM And a signal amplitude and phase predistortion device, a method and an orthogonal frequency division multiplexing transmission system using the same for reducing the peak-to-average power ratio (PAPR) in a broadcasting system will be.

So far, among many ways to reduce the peak-to-average power ratio (PAPR), the Simple Amplitude Predistortion technique achieves the desired peak-to-average power ratio instead of increasing a little power. In addition, due to the advantages of no loss of error-per-bit (BER) and no additional information and processing on the receiver side, much attention is paid to other techniques. However, in the process of finding the desired peak-to-average power ratio, there was a limitation in reducing the peak-to-average power ratio because only the signal size of each carrier was distorted while the phase was fixed.

The present invention has the existing advantages in place of the Simple Amplitude Predistortion technique and can achieve a better peak-to-average power ratio (PAPR) while varying up to phase. Here, the constellation extension method with a systematic search is called a simple signal amplitude and phase predistortion technique.

In general, orthogonal frequency division multiplexing (OFDM) is strong in fading at high transmission rates, has an efficient bandwidth due to orthogonal characteristics, and has the advantage of simplifying an equalizer. While there are these advantages, Orthogonal Frequency Division Multiplexing (OFDM) symbols have a high peak-to-average power ratio (PAPR).

First, an equation for a symbol of an orthogonal frequency division multiplexing (OFDM) scheme may be defined as shown in Equation 1 below.

Here, J is a coefficient of transient sampling, and when J = 4, almost all peak signals that may be missed in the discrete signal may be represented.

The peak power to average power ratio (PAPR) for the OFDM symbol may be defined as shown in Equation 2 below.

This high peak-to-average power ratio (PAPR) reduces power efficiency in high-power amplifiers (HPAs) and increases the dynamics of digital-to-analog converters (DACs) / analog-to-digital converters (ADCs). There is a disadvantage that the range is large. In addition, there are performance disadvantages such as reduction of error rate (BER) due to in-band distortion and interference between channels due to out-band expansion.

To overcome these drawbacks, the peak-to-average power ratio must be reduced. Many techniques have been introduced. Typically, a method of reducing PAPR includes clipping, block coding, phase adjustment, and active constellation extension.

First, as a prior art of the clipping method, an invention entitled “Peak Power versus Average Power Reduction Device and Method in Orthogonal Frequency Division Multiple Wireless Communication System” is disclosed in Korean Patent Application No. 2001-0088387.

The clipping method is the simplest method of forcibly cutting the size when the signal size is larger than the predetermined value. However, in-band distortion occurs due to nonlinear operation, resulting in poor bit error rate (BER) performance. Adjacent channel interference occurs with out-band noise.

Block coding is a method of simultaneously reducing PAPR and coding gain, but it is difficult to find an optimal code and requires a large amount of storage space for encoding and decoding. In addition, additional bit insertions require wide bandwidth.

The phase adjustment method includes Partial Transmit Sequence (PTS) and Selective Mapping (SLM). The prior art of the SLM, Korean Patent Application No. 2004-0071447 discloses an invention named "apparatus and method for reducing the ratio of the maximum power to the average power in the orthogonal frequency division multiplexing system".

SLM is the most effective way to reduce PAPR without nonlinear distortion. However, it is necessary to inform the receiver of additional phase information, and the complexity of finding an optimal phase increases exponentially as the number of carriers increases.

Finally, there is an active constellation extension method. The preceding paper is published under the name Broadcasting, IEEE Transactions (Volume 49, Issue 3, Sept. 2003 Page (s): 258-268) "PAR reduction in OFDM via active constellation extension".

Specifically, in the preceding paper, when the fast Fourier transform (FFT) and the inverse fast Fourier transform (IFFT) are repeated, there are constellation points that go out while maintaining a minimum distance from the original constellation point. PAPR can be reduced by mapping the rest to the point keeping the minimum distance.

The active constellation extension method has the following characteristics compared to other methods. There is no BER reduction and no additional information and processing is required at the receiving end. However, this method has a problem in that it causes a high complexity due to the repetition of the fast Fourier transform (FFT) and the inverse fast Fourier transform (IFFT) and an average power increase due to an increase in the origin of constellations.

The present invention has been proposed to solve the above problems, and a signal magnitude and phase predistortion apparatus and method for distorting each constellation point in magnitude and phase according to contributions between orthogonal frequency division multiplexing (OFDM) symbols The purpose is to provide.

In addition, the present invention uses a signal size and a phase predistortion technique to reduce the computational complexity of the system in a wireless communication and broadcasting system using an Orthogonal Frequency Division Multiplexing (OFDM) method while reducing the peak power to average power ratio (PAPR). Another object of the present invention is to provide an orthogonal frequency division multiplexing system and a method for effectively reducing the same.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

An apparatus of the present invention for achieving the above object is a signal magnitude and phase predistortion apparatus in a multi-carrier communication system, an inverse fast Fourier transform (IFTT) multiple carrier and one orthogonal frequency division multiplexing of the multiple carriers combined Measuring means for measuring a contribution between (OFDM) symbols; Calculating means for obtaining a signal magnitude and a phase coefficient to be increased in each carrier signal based on the contribution measured by the measuring means; And distortion means for distorting each constellation point to a corresponding magnitude and phase by using the signal magnitude and phase coefficient obtained by the calculation means.

와 위상

)으로 왜곡시키는 단계를 포함한다.In addition, the method of the present invention to achieve the above object, in the method of pre-distorting the signal size and phase in a multi-carrier communication system, the multiple-sampled multiple carriers and the multiple carriers transformed through an inverse fast Fourier transform Measuring the contribution between one orthogonal frequency division multiplexing (OFDM) symbol; Obtaining a signal magnitude and a phase coefficient to be increased in each carrier signal based on the measured value; And a magnitude corresponding to each constellation point by transferring the obtained signal magnitude and phase coefficient to a modulator.

And phase

Distortion).

와 위상

으로 왜곡시키는 왜곡 수단을 구비하는 신호 크기와 위상 선왜곡 수단을 포함하되, 상기 신호 크기와 위상 선왜곡 수단을 이용하여 상기 원래의 OFDM 심볼의 첨두신호(peak signal)를 줄여 송신하는 것을 특징으로 한다.On the other hand, the system of the present invention for achieving the above another object, converts serial data sequentially input into N (N is a natural number) parallel data, and modulated and inverse fast Fourier transform using the converted parallel data In an orthogonal frequency division multiplexing (OFDM) transmission system, a single OFDM symbol is produced and an excessive OFDM sample is taken to make the original OFDM symbol similar to an actual continuous OFDM symbol. Measuring means for measuring a contribution between a Fourier Transformed (IFTT) multiple carrier and one orthogonal frequency division multiplexing (OFDM) symbol in which the multiple carriers are combined; Calculating means for obtaining a signal magnitude and a phase coefficient to be increased in each carrier signal based on the contribution measured by the measuring means; And a signal magnitude corresponding to each constellation point by using the signal magnitude and phase coefficient obtained by the calculation means.

And phase

And a signal magnitude and phase predistortion means having distortion means for distorting the signal, and reducing and transmitting a peak signal of the original OFDM symbol by using the signal magnitude and phase predistortion means. .

와 위상

)으로 왜곡시켜 상기 원래의 OFDM 심볼의 첨두신호(peak signal)를 줄여 송신하는 단계를 포함한다.In addition, the method of the present invention for achieving the above another object is to convert serial data sequentially input into N (N is a natural number) parallel data, and modulated and inverse fast Fourier transform using the converted parallel data An inverse fast frequency division multiplex (OFDM) transmission method in which one OFDM symbol is made (IFFT), and an over-sample is taken to make the original OFDM symbol similar to an actual continuous OFDM symbol. Measuring a contribution between a multiple carrier transformed by a Fourier transform and an oversampled orthogonal frequency division multiplexing (OFDM) symbol in which the multiple carriers are combined; Obtaining a signal magnitude and a phase coefficient to be increased in each carrier signal based on the measured value; And a magnitude corresponding to each constellation point by transferring the obtained signal magnitude and phase coefficient to a modulator.

And phase

And reducing the peak signal of the original OFDM symbol to transmit the signal.

As described above, in the present invention, a symbol of an Orthogonal Frequency Division Multiplexing (OFDM) system is composed of N carriers, and the signal magnitude and phase of each carrier are distorted in advance.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1A is a block diagram of an exemplary embodiment of a signal amplitude and phase line distortion device and an orthogonal frequency division multiplexing (OFDM) transmission system using the same. In FIG. M-QAM, "13" is N point inverse fast Fourier transform (IFFT), "14" is parallel / serial conversion, "15" is oversampling, "16" is signal magnitude and phase line Distortion apparatus (hereinafter referred to as signal magnitude and phase predistortion algorithm) are respectively shown.

As shown in FIG. 1A, serial data sequentially input in an OFDM communication and broadcasting system is converted into N parallel data by the serial / parallel converter 11, and the parallel data is converted into M-QAM by the modulator 12. After the modulation, it is transferred to the N point inverse fast Fourier transform unit 13 to perform OFDM modulation.

Then, one OFDM symbol is made through the parallel / serial converter 14, and the original OFDM symbol is made by performing transient sampling to make the signal similar to the actual continuous OFDM symbol. In this case, in the transmission apparatus for reducing the peak-to-average power ratio (PAPR), the above object can be achieved by additionally inserting the signal magnitude and the phase predistortion algorithm 16.

This signal magnitude and phase predistortion algorithm 16 measures the contribution between the N carriers that have passed through the inverse fast Fourier transform section 13 and the OFDM symbol in which these carriers are combined and increases it with respect to each carrier signal based on this. The coefficient to be obtained is obtained.

In addition, the process of finding higher contributions to phase shifting results in an OFDM symbol with a low peak-to-average power ratio (PAPR). The better peak-to-average power ratio can be obtained by additionally configuring the signal magnitude and phase predistortion algorithm 16 in a conventional OFDM-based transmitter.

Here, the signal magnitude and phase predistortion device (algorithm) 16 having the above function will be described with reference to FIG. 1B as an example.

Figure 1b is a detailed configuration diagram of an embodiment of the signal amplitude and phase line distortion device according to the present invention.

As shown in Fig. 1B, the signal magnitude and phase predistortion apparatus according to the present invention provides a contribution between an inverse fast Fourier transform (IFTT) multiple carrier and one orthogonal frequency division multiplexing (OFDM) symbol in which the multiple carriers are combined. (Measurement unit 21) for measuring (Contribution), arithmetic unit (22) for obtaining a signal magnitude and phase coefficient to increase to each carrier signal based on the contribution measured by the measuring unit (21), and the operation unit And a distortion unit 23 for distorting each constellation point to a corresponding magnitude and phase using the signal magnitude and phase coefficient obtained in (22).

2 is a constellation diagram showing signal magnitude and phase line distortion of some carriers for QPSK, N = 128 obtained in the signal magnitude and phase line distortion device according to the present invention.

를 이용해서 각 성상점(Constellation Point)마다 해당하는 크기

와 위상

으로 왜곡시킨 것이다.As shown in Fig. 2, the signal magnitude and the two coefficients obtained by the phase line distortion algorithm 16

Size for each constellation point using

And phase

It is distorted.

In general, the signal magnitude and phase predistortion algorithm 16 can be expressed as follows.

와 이 캐리어들이 합쳐진 한 OFDM 심볼(

) 사이에 기여도(Contribution)를 나타낸다. 즉,

가

값을 가질 때, 역 고속 푸리에 변환부를 거친 N개의 캐리어와 이 캐리어들이 합쳐진 한 OFDM 심볼 사이에 위상 차이가 180도이기 때문에 f(n,k)는 최대값을 가지게 된다. 즉,

값에 근접한 캐리어들의 신호를 키워주면 상대적으로 많이 OFDM 심볼을 줄어들게 할 수 있다. 뿐만 아니라, 각 캐리어마다 위상을 조금씩 변화시키면 더 나은 비용함수의 값을 얻을 수 있다. 상기의 과정을 비용함수(Cost Function)의 수식으로 나타내면, 다음의 [수학식 4]와 같이 정의할 수 있다.Wherein, defining a cost function (Cost Function) as f (n, k), and is expressed as f (n, k) = -cos (θ nk). Cost function consists of N carriers that have undergone an inverse fast Fourier transform.

And an OFDM symbol where these carriers are combined

Indicates the contribution between). In other words,

end

When having a value, f (n, k) has a maximum value because the phase difference is 180 degrees between the N carriers through the inverse fast Fourier transform unit and the OFDM symbol in which these carriers are combined. In other words,

Increasing the signal of carriers close to the value can reduce the OFDM symbol relatively much. In addition, changing the phase slightly for each carrier yields a better cost function. When the above process is represented by a formula of Cost Function, it can be defined as Equation 4 below.

는 비트당 에러율(BER)의 감소를 방지하기 위해 최소거리(Minimum Distance)를 유지하는 선에서 각 성상점의 위상을 제약시켰고,

는 다음의 [수학식 5]에서 정의된다.here,

Constrains the phase of each constellation point on the line that maintains the minimum distance to prevent a reduction in the BER.

Is defined in Equation 5 below.

은 가중 함수(Weight Function)라 부르고, 한 OFDM 심볼 구간에 서로 크기가 다른 첨두 신호에 대한 가중값 p를 설정함으로써 상대적으로 큰 첨두신호를 더 많이 줄이는데 중요한 역할을 한다.As defined in Equation 3 above

Is called a weight function, and plays an important role in reducing a relatively large peak signal by setting weight values p for peak signals having different sizes in one OFDM symbol interval.

은 다음의 [수학식 6]에서 정의된다.Weight Function

Is defined in Equation 6 below.

일 때 상당히 좋은 결과를 얻을 수 있다.Where p is an experimental result

You can get quite good results when

As a result, when the equation defined in Equation 3 is solved using the above contents, it can be expressed as Equation 7 below.

는 한계치(Threshold Value) 신호크기를 초과하는 신호값의 집합을 의미하고,

는 하기의 [수학식 8]에서 볼 수 있듯이

를 구하는데 중요한 척도(Metric)로 사용된다.here,

Means a set of signal values exceeding the threshold value signal size,

Is shown in Equation 8 below.

It is used as an important metric for finding

만큼 선형적으로 옮긴 다음

에 해당하는 위상으로 이동시켜 하기의 [수학식 8]과 같이 준최적(suboptimal) 값,

을 얻을 수 있다.As shown in FIG. 2, cost functions are presented in order of increasing values.

Linearly by

Move to the phase corresponding to the suboptimal value as shown in [Equation 8],

Can be obtained.

는 양의 값만을 의미하고, 보통

과

는 이론적으로 구해지는 것이 아니라 많은 시뮬레이션 결과로 얻어지는데,

일 때

의 값들 중에 내림차순으로 15개 정도가 준최적의 PAPR을 얻는데 적당하다.here,

Means only positive values, usually

and

Is not obtained theoretically, but is obtained from many simulation results.

when

Of the values of, 15 in descending order are appropriate for obtaining a suboptimal PAPR.

FIG. 3 is a view of converting the constellation of FIG. 2 into an OFDM symbol, comparing an original OFDM symbol with an OFDM symbol using a simple signal size and a phase line distortion technique.

As shown in FIG. 3, it can be seen that the peak signal of the original OFDM symbol is significantly reduced.

와 이 캐리어들이 합쳐진 한 OFDM 심볼(

) 사이의 기여도(Contribution)를 나타낸 것이다.FIG. 4 is a diagram illustrating a correlation between each carrier signal and OFDM symbols formed by gathering carriers according to the present invention. N carriers passing through an inverse fast Fourier transform unit 13 are shown in FIG.

And an OFDM symbol where these carriers are combined

) Shows the contribution between.

As shown in FIG. 4, the number of carriers used for the actual PAPR reduction in the signal size predistortion technique is 25 to 35, but it can be seen that the signal size and the phase predistortion technique are statistically increased to 100. In addition, it can be seen that the cost function value is larger than the signal size predistortion technique.

에서 수정된 캐리어 개수에 따른 첨두전력 대 평균전력 비(PAPR)를 나타낸 도면으로,

와

값은 매번 OFDM 심볼이 변할 때마다 바꿀 필요없이 특정 값에서 준최적인 PAPR을 얻을 수 있다.5 shows the cumulative density function (CCDF)

Figure showing the peak-to-average power ratio (PAPR) according to the number of carriers modified in

Wow

The value can get a sub-optimal PAPR at a specific value without having to change it each time the OFDM symbol changes.

FIG. 6 is a diagram illustrating a change in the cumulative density function (CCDF) of an OFDM symbol using a signal size predistortion technique (SAP) and a signal size and a phase predistortion technique (SAPP). We can see that it is a 0.5dB improvement over the technique.

As described above, the present invention can achieve better PAPR by changing the phase while having the existing advantages. This constellation extension with systematic search reduces the peak-to-average power ratio, making it suitable for OFDM-based communication and broadcasting systems.

As described above, the method of the present invention may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form. Since this process can be easily implemented by those skilled in the art will not be described in more detail.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

As described above, the present invention provides a peak power to average power ratio (PAPR) while minimizing the computational complexity of a system in a wireless communication and broadcasting system using an orthogonal frequency division multiplexing (OFDM) method with an improved signal size and phase predistortion technique. ) Can be effectively lowered. When the PAPR is lowered, power loss of the high output power amplifier (HPA) decreases, and the high output power amplifier (HPA) prevents saturation, thereby providing high quality communication.

In addition, the simple signal size and phase predistortion technique, which is a kind of active constellation extension method, have no loss of per bit error rate (BER) and have no additional information and processing on the receiver side. In the conventional simple signal size predistortion technique, even the phase is used, which may result in improved performance as illustrated in FIG. 6.

Claims (19)

A signal magnitude and phase predistortion apparatus in a multicarrier communication system, Measurement means for measuring a contribution between an inverse fast Fourier transform (IFTT) multiple carrier and one orthogonal frequency division multiplexing (OFDM) symbol in which the multiple carriers are combined; Calculating means for obtaining a signal magnitude and a phase coefficient to be increased in each carrier signal based on the contribution measured by the measuring means; And Distortion means for distorting the corresponding magnitude and phase for each constellation point by using the signal magnitude and phase coefficient obtained by the calculation means Signal magnitude and phase predistortion device comprising a. The method of claim 1, The signal magnitude and phase line distortion device (algorithm), A signal magnitude and phase predistortion device, characterized in that the signal is distorted by a corresponding signal magnitude and phase for each constellation point using a cost function and a weight function. The method of claim 2, The weighting function is A signal amplitude and phase predistortion apparatus for setting a weighting value for peak signals having different magnitudes in one OFDM symbol interval in order to further reduce a relatively large peak signal. The method of claim 3, wherein The signal magnitude and phase line distortion device (algorithm), Signal magnitude corresponding to each constellation point

And phase

A signal magnitude and phase line distortion device, which are distorted as shown in Equation 1 below. [Equation 1]

( Where f (n, k) is defined as Cost Function and is expressed as f (n, k) = -cos (θ _nk ) ,

Is the weight function.) The method of claim 4, wherein In Equation 1, the cost function f (n, k) is It represents the contribution between the multiple carriers subjected to the Inverse Fast Fourier Transform (IFFT) and one OFDM symbol in which the multiple carriers are combined, and the contribution is expressed by Equation 2 below. And phase line distortion device. [Equation 2]

(here,

Constrains the phase of each constellation point on the line that maintains the minimum distance to prevent a reduction in the BER.

Is

Same as) The method of claim 4, wherein Weighting function in Equation 1

silver, Signal magnitude and phase line distortion device, characterized in that represented by the following [Equation 3]. [Equation 3]

Where p is defined as 6. The method according to any one of claims 4 to 6, The signal magnitude and phase line distortion device (algorithm), Signal amplitude and phase line distortion device, characterized in that expressed as shown in [Equation 4] using the equation defined in [Equation 1]. [Equation 4]

(here,

Means a set of signal values that exceed the threshold signal size,

Is

Used as an important measure to find The method of claim 7, wherein In order of increasing values through the cost function

Linearly by

Sub-optimal value as shown in [Equation 5] by moving to the phase corresponding to

Signal magnitude and phase line distortion device, characterized in that to obtain. [Equation 5]

(here,

Means only positive values) The method of claim 8, The signal size

Is, It operates with the algorithm of Equation 5 above, and important parameters

With the number of

Have values of about 15 and 60, respectively,

Signal magnitude and phase predistortion, characterized in that when the selection is made in descending order from the larger value. The method of claim 9, The phase

silver, A signal magnitude and phase line distortion device, which operates with the algorithm of Equation 4 and constrains the phase of each carrier in a line maintaining a minimum distance in order to prevent a reduction in an error rate per bit (BER). A method for predistorting signal size and phase in a multicarrier communication system, Measuring a contribution between a multiple carrier transformed by an inverse fast Fourier transform and an over-sampled orthogonal frequency division multiplexing (OFDM) symbol in which the multiple carriers are combined; Obtaining a signal magnitude and a phase coefficient to be increased in each carrier signal based on the measured value; And The magnitude corresponding to each constellation point by transferring the obtained signal magnitude and phase coefficient to a modulator.

And phase

To distort Signal magnitude and phase predistortion method comprising a. Serially input serial data is converted into N (N is a natural number) parallel data, and one OFDM symbol modulated and inverse fast Fourier transform (IFFT) is generated using the converted parallel data, and the OFDM symbol is In an orthogonal frequency division multiplexing (OFDM) transmission system, which takes a transient sampling to make the original OFDM symbol similar to an actual continuous OFDM symbol, Measurement means for measuring a contribution between an inverse fast Fourier transform (IFTT) multiple carrier and one orthogonal frequency division multiplexing (OFDM) symbol in which the multiple carriers are combined; Calculating means for obtaining a signal magnitude and a phase coefficient to be increased in each carrier signal based on the contribution measured by the measuring means; And Signal magnitude corresponding to each constellation point using the signal magnitude and phase coefficient obtained by the calculation means

And phase

A signal magnitude and phase predistortion means having distortion means for distorting Orthogonal frequency division multiplexing system characterized by reducing the peak signal of the original OFDM symbol by using the signal magnitude and phase predistortion means. The method of claim 12, The signal magnitude and phase predistortion means, An orthogonal frequency division multiplexing transmission system comprising a cost function and a weight function to distort a signal size and phase for each constellation point. The method of claim 13, The weighting function is An orthogonal frequency division multiplexing system characterized by setting weighting values for peak signals having different magnitudes in one OFDM symbol interval in order to further reduce relatively large peak signals. The method of claim 14, The signal magnitude and phase predistortion means, Orthogonal frequency division multiplexing transmission system characterized by the following Equation (6). [Equation 6]

( Where f (n, k) is defined as Cost Function and is expressed as f (n, k) = -cos (θ _nk ) ,

Is the weight function.) The method according to claim 14 or 15, The signal magnitude and phase predistortion means, Orthogonal frequency division multiplexing transmission system, characterized in that expressed as shown in Equation 7 below using the equation defined in Equation 6. [Equation 7]

(here,

Means a set of signal values that exceed the threshold signal magnitude,

Is

Used as an important measure to find The method of claim 16, The signal size

Is, Important parameters

With the number of

Have values of about 15 and 60, respectively,

Orthogonal frequency division multiplexing system, characterized in that is selected from large values in descending order when is selected. The method of claim 17, The phase

silver, An orthogonal frequency division multiplexing system, characterized in that the phase of each carrier is constrained in a line maintaining a minimum distance to prevent a reduction in the error rate per bit (BER). Serially input serial data is converted into N (N is a natural number) parallel data, and one OFDM symbol modulated and inverse fast Fourier transform (IFFT) is generated using the converted parallel data, and the OFDM symbol is In a method of orthogonal frequency division multiplexing (OFDM) transmission, in which transient sampling is taken to make an original OFDM symbol similar to an actual continuous OFDM symbol, Measuring a contribution between a multiple carrier transformed by an inverse fast Fourier transform and an over-sampled orthogonal frequency division multiplexing (OFDM) symbol in which the multiple carriers are combined; Obtaining a signal magnitude and a phase coefficient to be increased in each carrier signal based on the measured value; And The magnitude corresponding to each constellation point by transferring the obtained signal magnitude and phase coefficient to a modulator.

And phase

Transmitting the signal by reducing the peak signal of the original OFDM symbol Orthogonal frequency division multiplex transmission method comprising a.

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