KR20060074800A - Method and apparatus for transmitting/receiving a signal in a fast frequency hopping - orthogonal frequency division multiplexing communication system - Google Patents

Abstract

The present invention divides an entire frequency band into a plurality of subcarrier bands, and has a fast frequency hopping-orthogonal frequency division multiplexing (FFH-OFDM) having a plurality of subchannels that are a set of at least one subcarrier bands. In an Orthogonal Frequency Division Multiplexing) communication system, null data is inserted into subcarriers except for a preset number of subcarriers to transmit input data of the plurality of subcarriers, and input data is set to the set number. After the subcarriers are input in one-to-one correspondence, the subcarrier signals into which the null data is inserted are input to perform the fast frequency hopping corresponding to the preset fast frequency hopping pattern, and then the fast frequency hopping signal is fast Fourier. Of the set number in the fast Fourier transformed signal After inserting null data into subcarriers other than the subcarriers, subcarrier signals other than the set number of subcarrier signals with the fast Fourier transform and the set number of subcarriers with null data inserted in the fourth process Inputs an inverse fast Fourier transform and transmits the inverse fast Fourier transformed signal.

Fast frequency hopping, some frequency bands, full frequency band

Description

TECHNICAL AND APPARATUS FOR TRANSMITTING / RECEIVING A SIGNAL IN A FAST FREQUENCY HOPPING-ORTHOGONAL FREQUENCY DIVISION MULTIPLEXING COMMUNICATION SYSTEM}

1 is a block diagram showing a transmitter structure of a fast frequency hopping-OFDM communication system performing a function in the first embodiment of the present invention.

2 is a block diagram showing a receiver structure of a fast frequency hopping-OFDM communication system performing a function in the first embodiment of the present invention.

3 is a block diagram showing a transmitter structure of a fast frequency hopping-OFDM communication system performing a function in the second embodiment of the present invention.

4 is a block diagram showing a receiver structure of a fast frequency hopping-OFDM communication system performing a function in the second embodiment of the present invention.

5 is a block diagram showing a transmitter structure of a fast frequency hopping-OFDM communication system performing a function in the third embodiment of the present invention.

6 is a block diagram showing a receiver structure of a fast frequency hopping-OFDM communication system performing a function in the third embodiment of the present invention.

7 is a block diagram showing a transmitter structure of a fast frequency hopping-OFDMA communication system performing a function in the fourth embodiment of the present invention.

The present invention provides a communication system using a fast frequency hopping (FFH) method and an orthogonal frequency division multiplexing (OFDM) method (hereinafter referred to as 'high frequency hopping-OFDM'). The present invention relates to an apparatus and method for transmitting and receiving signals using only a part of frequency bands of all frequency bands used in the fast frequency hopping-OFDM communication system.

In the 4th generation (4G) mobile communication system, which is the next generation communication system, various quality of service (QoS: quality of service, hereinafter referred to as 'QoS') having a high transmission speed are referred to. Active research is being conducted to provide services to users. Therefore, in the current 4G mobile communication system, a wireless local area network (LAN) system and a wireless metropolitan area network (MAN) that guarantee a relatively high transmission speed are referred to as 'MAN'. Researches are being actively conducted to support high-speed services by developing new communication systems in the form of ensuring mobility and QoS in the system.

In order to support a broadband transmission network on a physical channel of the wireless MAN system, an OFDM scheme and an Orthogonal Frequency Division Multiple Access (OFDMA) scheme are referred to. The trend is being actively used. The OFDM / OFDMA scheme enables high-speed data transmission by transmitting a physical channel signal using a plurality of sub-carriers, and frequency diversity by using different subcarrier bands for frequency bands to which signals are transmitted. (frequency diversity) A method for obtaining a gain.

Since the OFDM communication system uses a plurality of subcarriers, a symbol period is longer in proportion to the number of subcarriers in comparison to the case of using a single subcarrier in terms of the same data rate, a guard interval, For example, effective OFDM by copying first constant samples of a guard interval or time-domain OFDM symbol inserted in the 'cyclic prefix' method of copying the last constant samples of the OFDM symbol in the time domain and inserting them into the effective OFDM symbol. Inter-symbol interference (ISI) is used in a wireless channel having multipath fading when a guard interval inserted in a form of 'cyclic postfix' is inserted into a symbol. Can reduce the impact.

)를 샘플링 주기(T_s)의 역수배가 되도록(

) 설정함으로써 1개의 OFDM 심볼 주기 동안 캐리어간 간섭(ICI: Inter Carrier Interference, 이하 'ICI'라 칭하기로 한다)의 영향을 감소시킬 수 있다. 상기 서브 캐리어들이 직교하여 간섭의 영향이 존재하지 않을 경우 상기 OFDM 통신 시스템의 수신기에서는 비교적 간단한 단일 탭(tap) 등화기만을 사용하여 데이터를 복조할 수 있다. 또한, 상기 OFDM 통신 시스템은 역고속 푸리에 변환(IFFT: Inverse Fast Fourier Transform, 이하 'IFFT'라 칭하기로 한다) 방식 및 고속 푸리에 변환(FFT: Fast Fourier Transform， 이하 'FFT'라 칭하기로 한다) 방식을 사용하여 다수의 서브 캐리어들을 변복조하므로 시스템 복잡도를 최소화시킬 수 있다. 상기 IFFT 방식을 사용하는 역고속 푸리에 변환기(이하, 'IFFT기'라 칭하기로 한다)의 동작은 상기 OFDM 통신 시스템에서의 주파수 변조 동작에 해당하는 것이며, 이는 하기 수학식 1에 나타낸 행렬

로 표현 가능하다.In addition, the channel response of each subcarrier band is approximated to be flat in the subcarrier band, and the difference between each subcarrier frequency (

) Is the inverse of the sampling period (T _s )

By setting it, it is possible to reduce the influence of inter-carrier interference (ICI: referred to as "ICI") during one OFDM symbol period. When the subcarriers are orthogonal and there is no influence of interference, the receiver of the OFDM communication system may demodulate data using only a relatively simple single tap equalizer. In addition, the OFDM communication system includes an Inverse Fast Fourier Transform (IFFT) scheme and a Fast Fourier Transform (FFT) scheme. By using the modulation and demodulation of a plurality of sub-carriers can minimize the system complexity. An operation of an inverse fast Fourier transformer (hereinafter, referred to as an "IFFT unit") using the IFFT method corresponds to a frequency modulation operation in the OFDM communication system, which is a matrix represented by Equation 1 below.

Can be expressed as

는 크기가

인 IFFT 행렬을 나타낸다. 여기서, 상기 서브 채널이라 함은 다수의, 즉 적어도 1개 이상의 서브 캐리어들로 구성되는 채널을 의미한다. 또한, 상기 IFFT기에 대응되 는, 상기 FFT 방식을 사용하는 고속 푸리에 변환기(이하, 'FFT기'라 칭하기로 한다)의 동작은 상기 수학식 1에 나타낸 IFFT 행렬

의 허미시안(Hermitian)

으로 표현 가능하다. In Equation 1, Q represents the total number of subcarriers used in the OFDM communication system, n represents a sample index, and m represents a sub-channel index. As a result, the

Is the size

Represents an IFFT matrix. Here, the subchannel means a channel composed of a plurality of subcarriers, that is, at least one subcarrier. In addition, the operation of the fast Fourier transformer (hereinafter, referred to as an "FFT device") using the FFT method corresponding to the IFFT device is the IFFT matrix shown in Equation 1 above.

Hermitian of

Can be expressed as

As described above, since the OFDM communication system uses a plurality of subcarriers, when there are subcarriers undergoing a deep fading phenomenon among the plurality of subcarriers, the subcarriers undergoing the deep fading phenomenon are present. The data transmitted over is less likely to be normally demodulated at the receiver. Proposed schemes for overcoming the performance degradation due to the deep fading phenomenon include frequency hopping and forward error correction (FEC).

The frequency hopping method is a method of hopping a frequency band in which a signal is transmitted according to a predetermined frequency hopping pattern, thereby obtaining an averaged gain of inter-cell interference. That is, the frequency hopping scheme periodically subcarriers the frequency carrier pattern at predetermined time intervals to prevent a signal from being transmitted through subcarriers continuously undergoing deep fading to any one user according to a frequency selective channel characteristic. This is a method of transmitting a signal while leaping accordingly. Here, the frequency hopping period is an OFDM symbol time or a time corresponding to an integer multiple of the OFDM symbol. As a result, subcarriers that do not experience deep fading in the next OFDM symbol time may be transmitted to any user through subcarriers that experience deep fading in any OFDM symbol time. By transmitting the signal through it, the frequency diversity gain and the interference can be averaged so as not to be continuously affected by the deep fading phenomenon.

In addition, a combination of the frequency hopping scheme and the OFDM scheme is a FH-OFDM scheme, and the FH-OFDM scheme allocates different subchannels to each user and presets subchannels assigned to each of the users. By frequency hopping with a period, a frequency diversity gain and an interference averaging gain between adjacent cells can be obtained.

However, in order to obtain sufficient gain due to the frequency hopping scheme in the conventional OFDM communication system, frequency hopping is required over several OFDM symbol times, and the number of users must be large, and an appropriate frequency hopping pattern must be selected according to channels. There is a problem with limitations. In addition, in the conventional OFDM communication system, when a frequency hopping scheme is used, signals are not transmitted through subcarriers that continuously experience deep fading to one user, but transmitted through subcarriers that undergo deep fading every OFDM symbol time. The signal still has the problem that it is impossible to demodulate to the receiver.

Accordingly, an object of the present invention is to provide an apparatus and method for transmitting and receiving signals in a fast frequency hopping-OFDM communication system.

Another object of the present invention is to provide an apparatus and method for performing a high frequency hopping using only some frequency bands of all frequency bands used in a high frequency hopping-OFDM communication system.

The apparatus of the present invention for achieving the above objects; Fast Frequency Hopping-Orthogonal Frequency Division Multiplexing (OFDM) communication, which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. In the signal transmission apparatus of the system, the input data corresponding to a one-to-one correspondence to a predetermined number of subcarriers to transmit the input data of the plurality of subcarriers to correspond to a high-speed hopping pattern set in advance A fast frequency hopping to perform frequency hopping, a fast Fourier transformer for fast Fourier transforming the fast frequency honed signal, a controller for inserting null data into subcarriers except the set number of subcarriers, and the fast Fourier transform With a set number of subcarrier signals A first inverse fast Fourier transformer for inputting subcarrier signals excluding the set number of subcarriers into which null data is inserted, and an inverse fast Fourier transform; and a transmitter for transmitting an inverse fast Fourier transform signal from the first inverse fast Fourier transformer Characterized by including.

Another apparatus of the present invention for achieving the above objects; Fast Frequency Hopping-Orthogonal Frequency Division Multiplexing (OFDM) communication, which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. A signal receiving apparatus of a system, comprising: a first fast Fourier transformer for fast Fourier transforming a received signal, and a transmitting device transmitting data among the plurality of subcarriers in a fast Fourier transformed signal at the first fast Fourier transformer, A controller for removing signals corresponding to remaining subcarriers except a predetermined number of subcarriers and inserting null data to correspond to the remaining subcarriers, and a first equalization for equalizing output signals of the controller in a frequency domain. And a transmission field for equalizing the signal in the frequency domain. An inverse fast Fourier transformer for transforming the inverse fast Fourier transform corresponding to the fast frequency hopping matrix applied by < RTI ID = 0.0 >, < / RTI > a second equalizer for equalizing the inverse fast Fourier transform signal in the time domain, and a fast frequency hopping the equalized signal in the time domain. And a second fast Fourier transformer for fast Fourier transform corresponding to the Hermithian of the matrix.

Another apparatus of the present invention for achieving the above objects is; Fast Frequency Hopping-Orthogonal Frequency Division Multiplexing (OFDM) communication, which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. A signal transmission apparatus of a system, comprising: a first controller for inserting null data into subcarriers except for a predetermined number of subcarriers to transmit the input data among the plurality of subcarriers; A fast frequency hopping device that inputs one-to-one correspondence to the set number of subcarriers, and performs high-speed frequency hopping corresponding to a preset high-speed hopping pattern by inputting subcarrier signals into which null data is inserted in the first controller. And performing fast Fourier transform of the fast frequency honed signal. A fast Fourier transformer, a second controller for inserting null data into subcarriers other than the set number of subcarriers in the fast Fourier transformed signal, the set number of subcarrier signals and the second controller of the fast Fourier transform A first inverse fast Fourier transformer for inputting subcarrier signals excluding the set number of subcarriers into which the null data is inserted, and an inverse fast Fourier transform and a first inverse fast Fourier transform signal transmitted by the first inverse fast Fourier transformer It characterized in that it comprises a transmitter.

Another apparatus of the present invention for achieving the above objects is; Fast Frequency Hopping-Orthogonal Frequency Division Multiplexing (OFDM) communication, which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. A signal receiving apparatus of a system, comprising: a first fast Fourier transformer for fast Fourier transforming a received signal, and a transmitting device transmitting data among the plurality of subcarriers in a fast Fourier transformed signal at the first fast Fourier transformer, A first controller for removing signals corresponding to remaining subcarriers except a predetermined number of subcarriers and inserting null data to correspond to the remaining subcarriers, and equalizing an output signal of the first controller in a frequency domain A first equalizer for transmitting the equalized signal in the frequency domain An inverse fast Fourier transformer for inverse fast Fourier transform corresponding to the fast frequency hopping matrix applied by the apparatus, a second equalizer for equalizing the inverse fast Fourier transform signal in a time domain, and a signal equalized in the time domain for the fast frequency Removes the signals corresponding to the remaining subcarriers from the second fast Fourier transformer corresponding to the fast Fourier transform and the fast Fourier transform from the second fast Fourier transformer, And a second controller for inserting null data so as to correspond to.

The method of the present invention for achieving the above objects; Associating input data with one-to-one correspondence with a predetermined number of subcarriers to transmit the input data among the plurality of subcarriers, and then performing a fast frequency hopping corresponding to a preset high frequency hopping pattern; Performing fast Fourier transform on the fast frequency hopping signal, inserting null data into subcarriers other than the set number of subcarriers, and setting the number of subcarrier signals and the null data by the fast Fourier transform And inputting subcarrier signals excluding the set number of subcarriers into which the inverse fast Fourier transform is inserted, and transmitting the inverse fast Fourier transform signal.

Another method of the present invention for achieving the above objects is; Fast Frequency Hopping-Orthogonal Frequency Division Multiplexing (OFDM) communication, which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. A signal receiving method of a system, comprising: a first number of fast Fourier transforms of a received signal; and a preset number of data transmitted from the plurality of subcarriers by a transmitter in a fast Fourier transformed signal in the first step A second process of removing signals corresponding to the remaining subcarriers except the subcarriers, inserting null data to correspond to the remaining subcarriers, and a third process of equalizing a signal generated in the second process in a frequency domain And a high frequency frequency in which the signal equalized in the frequency domain is applied by the transmitting apparatus. A fourth process of inverse fast Fourier transform corresponding to the hopping matrix, a fifth process of equalizing the inverse fast Fourier transform signal in the time domain, and a signal equalized in the time domain in the Hermithian of the fast frequency hopping matrix And a sixth process for correspondingly fast Fourier transform.

Another method of the present invention for achieving the above objects is; Fast Frequency Hopping-Orthogonal Frequency Division Multiplexing (OFDM) communication, which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. A signal transmission method of a system, comprising: a first process of inserting null data into subcarriers except for a predetermined number of subcarriers to transmit the input data among the plurality of subcarriers; A second step of inputting one-to-one correspondence to the set number of subcarriers, and performing a fast frequency hopping corresponding to a preset high-speed hopping pattern by inputting subcarrier signals into which null data is inserted in the first step; A third step of performing fast Fourier transform of the fast frequency hopping signal; Inserting null data into subcarriers other than the predetermined number of subcarriers in the fast Fourier transformed signal; and null data in the fourth process and the fourth number of subcarrier signals of the fast Fourier transformed number And a fifth process of inputting subcarrier signals excluding the set number of subcarriers into the inverse fast Fourier transform, and transmitting the inverse fast Fourier transformed signal in the fifth process. .

Another method of the present invention for achieving the above objects is; Fast Frequency Hopping-Orthogonal Frequency Division Multiplexing (OFDM) communication, which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. A method of receiving a system, the method comprising: a first process of fast Fourier transforming a received signal; and a preset number of subs, in which the transmitting device transmits data among the plurality of subcarriers in the fast Fourier transformed signal in the first process A second process of removing signals corresponding to the remaining subcarriers except for carriers, inserting null data to correspond to the remaining subcarriers, and a third process of equalizing a signal generated in the second process in a frequency domain And a fast frequency hopping in which the signal equalized in the frequency domain is applied by the transmitting apparatus. A fourth process of inverse fast Fourier transform corresponding to the matrix, a fifth process of equalizing the inverse fast Fourier transformed signal in the time domain, and a signal equalized in the time domain in correspondence with the Hermithian of the fast frequency hopping matrix A sixth process of fast Fourier transform and a seventh process of removing signals corresponding to the remaining subcarriers from the fast Fourier transform signal in the sixth process and inserting null data to correspond to the remaining subcarriers Characterized in that it comprises a.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

The present invention relates to a communication system using a fast frequency hopping (FFH) scheme and an orthogonal frequency division multiplexing (OFDM) scheme (hereinafter referred to as 'OFH-OFDM communications system'). An apparatus and method for transmitting and receiving a signal by performing a fast frequency hopping using only some frequency bands of all the frequency bands used in the present invention will be described. In this case, the fast frequency hopping method is a method of performing frequency hopping at a high speed by setting a frequency hopping period to an OFDM sample period or an integer multiple of the OFDM samples rather than an OFDM symbol period. In case of using the fast frequency hopping method, one OFDM symbol is spread over a plurality of subcarriers in the frequency domain and transmitted.

First, a transmitter structure in the case of performing a fast frequency hopping using the entire frequency band in the FFH-OFDM communication system will be described with reference to FIG.

1 is a block diagram showing a transmitter structure of an FFH-OFDM communication system performing a function in the first embodiment of the present invention.

Referring to FIG. 1, the transmitter includes a serial to parallel converter 111, a fast frequency hopping device 120, a parallel to serial converter 131, and a guard interval. A guard interval inserter 133, a digital to analog converter 135, and a radio frequency (RF) processor 137 It is composed of In addition, the fast frequency hopping device 120 includes an inverse fast fourier transform (IFFT) device 121 and a linear processor 123.

라고 칭하기로 하며, 상기 병렬 신호

는 하기 수학식 2와 같이 표현된다.First, when input data symbols to be transmitted are generated, the input data symbols are input to the serial / parallel converter 111. Here, the data refers to reference data such as actual user data or pilot. The serial / parallel converter 111 converts the input data symbols in parallel and outputs them to the IFFT unit 121. Here, the parallel signal output from the serial / parallel converter 111

And the parallel signal

Is expressed as in Equation 2 below.

In Equation 2, T represents a transpose operation, and Q represents the total number of subcarriers used in the FFH-OFDM communication system.

를 Q-포인트(Q-point) IFFT를 수행한 후 상기 선형 처리기(123)로 출력한다. 상기 선형 처리기(123)는 상기 IFFT기(121)에서 출력한 신호를 입력하여 선형 처리한 후 상기 병렬/직렬 변환기(131)로 출력한다. The IFFT unit 121 outputs the signal output from the serial / parallel converter 111.

Is output to the linear processor 123 after performing a Q-point IFFT. The linear processor 123 inputs the signal output from the IFFT unit 121 and performs linear processing on the linear processor 123 to output the linear signal to the parallel / serial converter 131.

Next, operation of the IFFT unit 121 and the linear processor 123 will be described.

과는 상이한, 하기 수학식 3과 같은 새로운 행렬, 즉 고속 주파수 도약 방식을 적용하여 주파수 변조를 수행하는

크기의 행렬(이하, '고속 주파수 도약 행렬'이라 칭하기로 한다)

로 변경된다. 여기서, 상기 IFFT 행렬

는 상기 종래 기술 부분에서 설명한 바와 같이 IFFT기의 주파수 변조 동작에 해당하는 행렬이다. First, in FIG. 1, since the entire frequency band is used, the prior art portion of the present invention when performing a fast frequency hopping for subcarriers transmitting data every OFDM sample time or a time corresponding to a multiple of the OFDM sample time. IFFT matrix described in

Frequency modulation by applying a new matrix, that is, a fast frequency hopping scheme,

Matrix of magnitude (hereinafter, referred to as 'high-speed frequency hopping matrix')

Is changed to Where the IFFT matrix

Is a matrix corresponding to the frequency modulation operation of the IFFT unit as described in the prior art.

은 n번째 샘플에서 m번째 서브 채널의 데이터가 송신되는 서브 캐리어를 나타내며, 따라서

이 상기 고속 주파수 도약 수행 시 고속 주파수 도약 패턴을 결정한다. 또한, 본 발명에서는 임의의 샘플에서 데이터가 송신되는 서브 캐리어가 중복되지 않도록 하는 고속 주파수 도약 패턴을 가정하며, 모든 고속 주파수 도약 패턴들에 대해 상기 고속 주파수 도약 행렬

은 하기 수학식 4와 같이 표현된다. In Equation 3, n represents a sample index and m represents a sub-channel index. Also,

Denotes a subcarrier on which data of the mth subchannel is transmitted in the nth sample, and thus

When performing the fast frequency hopping, a fast frequency hopping pattern is determined. In addition, the present invention assumes a fast frequency hopping pattern that does not overlap the subcarriers to which data is transmitted in any sample, and the fast frequency hopping matrix for all fast frequency hopping patterns.

Is expressed as in Equation 4 below.

및 행렬

의 엘리먼트(element) 값들은 상기 고속 주파수 도약 패턴에 따라 미리 결정된 값으로 주어진다. 여기서, 상기 행렬

는 그 크기가

이다. Fast frequency hopping matrix in Equation 4

And matrices

The element values of are given by a predetermined value according to the fast frequency hopping pattern. Where the matrix

Its size

to be.

는 항상 대각(diagonal) 행렬로 생성된다. Assuming that f _n of the fast frequency hopping pattern is a subcarrier to which data of the first subchannel is transmitted in the nth sample, the following equation is used when the cyclic fast frequency hopping pattern defined by Equation 5 below is used. Matrix of four

Is always generated as a diagonal matrix.

은 일반적인 IFFT 행렬

에 상기 행렬

를 곱한 형태로 표현되며, 따라서 상기 고속 주파수 도약을 수행하는 장치는 IFFT기와 상기 행렬

를 곱해주는 선형 처리기로 구현 가능하게 되는 것이다. 한편, 본 발명에서는 설명의 편의상 상기 고속 주파수 도약 패턴을 순환 고속 주파수 도약 패턴을 일 예로 하여 설명하며, 따라서 상기 행렬

역시 대 각 행렬로 정의되는 것이며, 상기 고속 주파수 도약 패턴의 형태는 변형 가능함은 물론이다. In this case, the fast frequency hopping matrix

Is a typical IFFT matrix

On the matrix

Multiplied by, and thus the apparatus for performing the fast frequency hopping is the IFFT group and the matrix

This can be implemented with a linear processor that multiplies by. In the present invention, for convenience of description, the fast frequency hopping pattern will be described using a cyclic fast frequency hopping pattern as an example.

Again, it is defined as a diagonal matrix, and the shape of the fast frequency hopping pattern can be modified.

라고 표현하기로 하며, 상기 신호

는 하기 수학식 6과 같이 나타낼 수 있다.On the other hand, the signal output from the linear processor 123

And the signal

Can be expressed as in Equation 6 below.

를 입력하여 직렬 변환한 후 보호 구간 삽입기(133)로 출력한다. 상기 보호 구간 삽입기(133)는 상기 병렬/직렬 변환기(131)에서 출력한 신호를 입력하여 보호 구간 신호를 삽입한 후 상기 디지털/아날로그 변환기(135)로 출력한다. 여기서, 상기 보호 구간은 상기 FFH-OFDM 통신 시스템에서 OFDM 심벌을 송신할 때 이전 OFDM 심벌 시간에 송신한 OFDM 심벌과 현재 OFDM 심벌 시간에 송신할 현재 OFDM 심벌간에 간섭(interference)을 간섭을 제거하기 위해서 삽입된다. 또한, 상기 보호 구간 신호는 시간 영역의 OFDM 심벌의 마지막 일정 샘플들을 복사하여 유효 OFDM 심벌에 삽입하는 형태의 'Cyclic Prefix' 방식이나 혹은 시간 영역의 OFDM 심벌의 처음 일정 샘플들을 복사하여 유효 OFDM 심벌에 삽입하는 'Cyclic Postfix' 방식중 어느 한 방식을 사용하여 생성된다. The parallel / serial converter 131 outputs a signal output from the linear processor 123.

After inputting the serial conversion, and outputs to the guard interval inserter (133). The guard interval inserter 133 inputs a signal output from the parallel / serial converter 131 to insert a guard interval signal and outputs the guard interval signal to the digital / analog converter 135. In this case, the guard period is used to remove interference between the OFDM symbols transmitted at the previous OFDM symbol time and the current OFDM symbols to be transmitted at the current OFDM symbol time when transmitting the OFDM symbols in the FFH-OFDM communication system. Is inserted. In addition, the guard interval signal is a 'Cyclic Prefix' scheme in which the last constant samples of the OFDM symbol in the time domain are copied and inserted into the effective OFDM symbol, or the first constant samples of the OFDM symbol in the time domain are copied to the valid OFDM symbol. It is created using one of the 'Cyclic Postfix' methods.

The digital-to-analog converter 135 inputs the signal output from the guard interval inserter 133 and converts the analog signal to the RF processor 137. Here, the RF processor 137 includes components such as a filter and a front end unit. The RF processor 137 RF-processes the signal output from the digital-to-analog converter 135 and then transmits the signal to an actual channel. .

In FIG. 1, a transmitter structure of an FFH-OFDM communication system performing a function in the first embodiment of the present invention has been described. Next, referring to FIG. 2, the function of the transmitter in the first embodiment of the present invention is performed. The receiver structure of the FFH-OFDM communication system will be described.

2 is a block diagram showing a receiver structure of an FFH-OFDM communication system performing a function in the first embodiment of the present invention.

Referring to FIG. 2, the receiver includes an RF processor 211, an analog / digital converter 213, a channel estimator 215, and a guard interval remover. 217, a serial / parallel converter 219, a Fast Fourier Transform (FFT) 221, an equalizer 223, An IFFT device 225, an equalizer 227, an FFT device 229, and a parallel / serial converter 231 are configured.

라고 칭하기로 하며, 상 기 잡음을

이라고 칭하기로 하며, t는 시간 영역(time domain)에서 측정된 것임을 나타낸다. 상기 RF 처리기(211)는 상기 안테나를 통해 수신된 신호를 중간 주파수(IF: Intermediate Frequency) 대역으로 다운 컨버팅(down converting)한 후 상기 아날로그/디지털 변환기(213)로 출력한다. 상기 아날로그/디지털 변환기(213)는 상기 RF 처리기(211)에서 출력한 아날로그 신호를 디지털 변환한 후 상기 채널 추정기(215) 및 보호 구간 제거기(217)로 출력한다. First, a signal transmitted from a transmitter of the FFH-OFDM communication system as described above with reference to FIG. It is input to the RF processor 211 through the antenna in the form. Here, a channel matrix representing a channel response of the multipath channel is obtained.

Will be called, and the noise

And t denotes that it is measured in the time domain. The RF processor 211 down-converts the signal received through the antenna to an intermediate frequency (IF) band and outputs the converted signal to the analog-to-digital converter 213. The analog / digital converter 213 digitally converts the analog signal output from the RF processor 211 and outputs the digital signal to the channel estimator 215 and the guard interval remover 217.

라고 칭하기로 하며, 상기 신호

는 시간 영역의 신호로서 하기 수학식 7과 같이 나타낼 수 있다.The channel estimator 215 inputs the signal output from the analog / digital converter 213 to perform channel estimation and outputs the result to the equalizer 223. Since the channel estimating operation of the channel estimator 215 is not directly related to the present invention, a detailed description thereof will be omitted. The guard interval remover 217 removes the guard interval signal by inputting the signal output from the analog / digital converter 213 and outputs the signal to the serial / parallel converter 219. The serial / parallel converter 219 inputs the signal output from the guard interval remover 217 to perform parallel conversion and outputs the signal to the FFT unit 221. Here, the signal output from the serial / parallel converter 219

And the signal

Is a signal in the time domain and can be represented by Equation 7 below.

를 Q-포 인트 FFT를 수행한 후 상기 등화기(223)로 출력한다. 여기서, 상기 FFT기(221)에서 출력하는 신호를

라고 칭하기로 하며, 상기 신호

는 주파수 영역의 신호로서 하기 수학식 8과 같이 나타낼 수 있다.The FFT unit 221 is a signal output from the serial / parallel converter 219

Is output to the equalizer 223 after performing a Q-point FFT. Here, the signal output from the FFT unit 221

And the signal

May be represented by Equation 8 as a signal in a frequency domain.

는 상기 IFFT 행렬

의 허미시안(Hermitian)을 나타낸다.In Equation 8,

Is the IFFT matrix

Hermitian of.

Meanwhile, an equalization operation must be performed to compensate for distortion of the signal caused by the multipath channel. In the FFH-OFDM communication system, the equalization operation must be performed in both the time domain and the frequency domain. Therefore, the equalizer also needs two equalizers of the equalizer in the time domain to input the signals in the time domain and the equalizer in the frequency domain to input the signals in the frequency domain to perform the equalization operation. do.

Accordingly, the equalizer 223 equalizes the signal output from the FFT 221 in the frequency domain and outputs the equalized signal to the IFFT 225. The equalizer 223 compensates for the channel response in the frequency domain. Since the FFH-OFDM communication system uses the guard interval signal, the channel response in the time domain and the channel response in the frequency domain have a Singular Value Decomposition relationship, which can be expressed by Equation 9 below.

는 주파수 영역에서의 채널 응답을 나타내는 채널 행렬을 나타내며, 상기 채널 행렬

은 대각 행렬이므로 단일 탭(tap) 등화기로도 구현 가능하다. 즉, 주파수 영역의 등화 동작을 수행하는 등화기(223)는 일반적인 OFDM 통신 시스템의 등화기와 실질적으로 동일한 동작을 수행하며, 채널 보상 방식에 따라 ZF(Zero Forcing) 등화기와, 최소 평균 제곱 에러(MMSE: Minimum Mean Square Error) 등화기와, 매칭 필터(matched filter) 등을 모두 포함하는 구조를 가진다. In Equation 9

Denotes a channel matrix representing a channel response in the frequency domain, wherein the channel matrix

Since is a diagonal matrix, it can be implemented as a single tap equalizer. That is, the equalizer 223 performing the equalization operation in the frequency domain performs substantially the same operation as the equalizer of the general OFDM communication system. The equalizer ZESE and the minimum mean square error (MMSE) according to the channel compensation scheme are used. : Minimum Mean Square Error) It has a structure including both an equalizer and a matched filter.

In addition, the IFFT unit 225 inputs the signal output from the equalizer 223 to perform a Q-point IFFT and outputs the same to the equalizer 227. Here, since the IFFT unit 225 performs the same operation as the IFFT unit 121 of the transmitter of FIG. 1, a detailed description thereof will be omitted.

으로 정의하기로 하며, 상기 시간 영역에서의 등화 동작

는 하기 수학식 10과 같이 나타낼 수 있다.The equalizer 227 inputs the signal output from the IFFT unit 225, equalizes the signal in the time domain, and outputs the equalized signal to the FFT unit 229. Here, the equalization operation in the time domain

The equalization operation in the time domain

Can be expressed as in Equation 10 below.

는 상기 수학식 4에서 나타낸 바와 같은 행렬

의 허미시안

으로 표현되며, 따라서 상기 행렬

역시 대각 행렬이 되는 것이다.Equalization operation in the time domain as shown in Equation 10

Is a matrix as shown in Equation 4 above.

Hermitian of

Is represented by

It is also a diagonal matrix.

는 하기 수학식 11과 같이 나타낼 수 있다.The FFT unit 229 inputs the signal output from the equalizer 227 to perform a Q-point FFT and outputs the same to the parallel / serial converter 231. Here, since the operation of the FFT unit 229 is substantially the same as the operation of the FFT unit 221, a detailed description thereof will be omitted. In addition, a signal output from the FFT unit 229, that is, an input data symbol estimation vector

Can be expressed as in Equation 11 below.

를 수행할 경우 상기 수학식 11에 나타낸 바와 같은 입력 데이터 심볼 추정 벡터

는 하기 수학식 12와 같이 나타낼 수 있다.For example, the equalizer 223 uses a ZF equalizer for classifying a channel response for each subcarrier with a signal in the frequency domain as shown in Equation 8, and the equalizer 227 is shown in Equation 10. Equalization behavior

Is performed, the input data symbol estimation vector as shown in Equation (11)

Can be expressed as

The parallel / serial converter 231 serially converts the signal output from the FFT unit 229 and outputs the final input symbols.

1 and 2 illustrate the FFH-OFDM communication system according to the first embodiment of the present invention, that is, performing a fast frequency hopping using the entire frequency band, and then, the second embodiment of the present invention. And an FFH-OFDM communication system according to the third embodiment, i.e., performing a fast frequency hopping using some frequency bands.

이라고 가정하 기로 한다.First, in the second and third embodiments of the present invention, the reason for considering the fast frequency hopping using some frequency bands is that a frequency corresponding to specific subcarriers in an actual FFH-OFDM communication system. In order to use the band as a guard band, the signal is not transmitted in the frequency band corresponding to the guard band, or each user is allocated a portion of the frequency band corresponding to specific subcarriers of the entire frequency bands. This is because there is a need for a method of transmitting. Particularly, in the FFH-OFDM communication system, the system uses a dynamic channel allocation (DCA) scheme for dynamically allocating subchannels according to the channel state of users at each time point. Performance will be greatly improved. Accordingly, in the second and third embodiments of the present invention, a method of performing a fast frequency hopping using some frequency bands of all frequency bands is proposed. Hereinafter, in describing the second and third embodiments of the present invention, it is assumed that the total number of subcarriers used in the FFH-OFDM communication system is Q, and the number of subcarriers corresponding to some frequency bands. To

Let's assume that.

In addition, briefly described the difference between the second embodiment and the third embodiment of the present invention as follows.

First, the second embodiment of the present invention performs fast frequency hopping on only the M subcarriers and transmits them, and null data for the remaining subcarriers, that is, QM subcarriers, for example, 0. Insert it and send it. In this case, assuming that the frequency band corresponding to the M subcarriers is the entire frequency band, the frequency band corresponding to the M subcarriers can be implemented in the same manner as described in the first embodiment of the present invention.

Next, the third embodiment of the present invention performs fast frequency hopping on a total of Q subcarriers of M subcarriers and QM subcarriers to spread data, and then QM except for the M subcarriers. The null data is inserted into the subcarriers and transmitted. That is, in the third embodiment of the present invention, after null data is pre-inserted into the QM subcarriers, fast frequency hopping is performed on the Q subcarriers, and then null data is inserted into the QM subcarriers. To transmit. However, in order for the third embodiment of the present invention to generate the same transmission signal as the second embodiment of the present invention, two conditions must be satisfied. The two conditions will be described in detail below. Will be omitted.

Next, a transmitter structure of the FFH-OFDM communication system performing a function in the second embodiment of the present invention will be described with reference to FIG. 3.

3 is a block diagram showing a transmitter structure of an FFH-OFDM communication system performing a function in the second embodiment of the present invention.

Referring to FIG. 3, the transmitter includes a serial / parallel converter 311, a fast frequency hopping device 320, an FFT device 331, a controller 333, an IFFT device 335, and a parallel / serial type. The converter 337, the guard interval inserter 339, the digital / analog converter 341, and the RF processor 343 are configured. In addition, the fast frequency hopping unit 320 is composed of an IFFT unit 321 and a linear processor 323.

라고 칭하기로 하며, 상기 병렬 신호

는 하기 수학식 13과 같이 표현된다.First, when input data symbols to be transmitted are generated, the input data symbols are input to the serial / parallel converter 311. Here, the data refers to reference data such as actual user data or pilot, and according to the second embodiment of the present invention, a case of performing a fast frequency hopping for only M subcarriers is proposed. ) Converts the input data symbols into M symbols in parallel and outputs them to the IFFT unit 321. Here, the parallel signal output from the serial / parallel converter 311

And the parallel signal

Is expressed by Equation 13 below.

를 M-포인트 IFFT를 수행한 후 상기 선형 처리기(323)로 출력한다. 상기 선형 처리기(323)는 상기 IFFT기(321)에서 출력한 신호를 입력하여 선형 처리한 후 상기 FFT기(331)로 출력한다. The IFFT unit 321 is a parallel signal output from the serial / parallel converter 311

The M-point IFFT is performed and then output to the linear processor 323. The linear processor 323 inputs the signal output from the IFFT unit 321 to perform linear processing and outputs the linear signal to the FFT unit 331.

The operation of the IFFT unit 321 and the linear processor 323 will now be described.

와 동일한 방식으로 생성되지만, 그 행렬 크기가 상이한 고속 주파수 도약 행렬

로 변경되며, 상기 고속 주파수 도약 행렬

은 하기 수학식 14와 같이 표현된다.First, in FIG. 3, only M subcarriers are used instead of the entire frequency band. Therefore, a fast frequency hopping is performed to hop subcarriers transmitting data every OFDM sample time or a time corresponding to a multiple of the OFDM sample time. When the fast frequency hopping matrix described in the first embodiment of the present invention

A fast frequency hopping matrix, generated in the same way as, but with different matrix sizes

The fast frequency hopping matrix

Is expressed by Equation 14 below.

은 그 크기가

이다.Fast frequency hopping matrix in Equation 14

Is that size

to be.

를 하기 수학식 15와 같이 표현할 수 있다.In addition, the present invention assumes a fast frequency hopping pattern that does not overlap the subcarriers to which data is transmitted in any sample, and the fast frequency hopping matrix for all fast frequency hopping patterns.

It may be expressed as in Equation 15 below.

및 행렬

의 엘리먼트 값들은 상기 고속 주파수 도약 패턴에 따라 미리 결정된 값으로 주어진다. Fast frequency hopping matrix in Equation 15

And matrices

The element values of are given by a predetermined value according to the fast frequency hopping pattern.

는 항상 대각 행렬로 생성된다. Assuming that f _n of the fast frequency hopping pattern is a subcarrier to which data of the first subchannel is transmitted in the nth sample, using the cyclic fast frequency hopping pattern defined by Equation 16, the matrix of Equation 15

Is always produced as a diagonal matrix.

은 일반적인 IFFT 행렬

에 상기 행렬

를 곱한 형태로 표현되며, 따라서 상기 고속 주파수 도약을 수행하는 장치는 IFFT기와 상기 행렬

를 곱해주는 선형 처리기로 구현 가능하게 되는 것이다. 한편, 본 발명에서는 설명의 편의상 상기 고속 주파수 도약 패턴을 순환 고속 주파수 도약 패턴을 일 예로 하여 설명하며, 따라서 상기 행렬

역시 대각 행렬로 정의되는 것이며, 상기 고속 주파수 도약 패턴의 형태는 변형 가능함은 물론이다. In this case, the fast frequency hopping matrix

Is a typical IFFT matrix

On the matrix

Multiplied by, and thus the apparatus for performing the fast frequency hopping is the IFFT group and the matrix

This can be implemented with a linear processor that multiplies by. In the present invention, for convenience of description, the fast frequency hopping pattern will be described using a cyclic fast frequency hopping pattern as an example.

Also defined as a diagonal matrix, the shape of the fast frequency hopping pattern is, of course, deformable.

라고 표현하기로 하며, 상기 신호

는 하기 수학식 17과 같이 나타낼 수 있다.On the other hand, the signal output from the linear processor 323

And the signal

Can be expressed as in Equation 17 below.

를 입력하여 M-포인트 FFT를 수행한 후 상기 제어기(333)로 출력한다. 상기 제어기(333)는 상기 FFT기(331)에서 출력한 신호를 입력하고, 상기 M개의 서브 캐리어 대역들 이외의 Q-M개의 서브 캐리어 대역들에 널 데이터, 일 예로 0을 삽입한 후 상기 IFFT기(335)로 출력한다. 여기서, 상기 제어기(333)는 일종의 0 삽입기(0 inserter)로서 동작하는 것이며, 상기 제어기(333)의 0 삽입 동작은 하기 수학식 18과 같이 나타낼 수 있다.The FFT unit 331 outputs a signal output from the linear processor 123.

To perform an M-point FFT and output to the controller 333. The controller 333 inputs a signal output from the FFT unit 331, inserts null data, for example, 0 into QM subcarrier bands other than the M subcarrier bands, and then inserts the IFFT unit ( 335). Here, the controller 333 operates as a kind of zero inserter, and the zero insertion operation of the controller 333 can be expressed by Equation 18 below.

은 상기 도 3의 제어기(333)의 동작을 나타내는 행렬이며, 상기에서 설명한 바와 같이 상기 제어기(333)의 출력 신호 중에서 상기 M개의 서브 캐리어들을 통해 송신되는 데이터들에 대해서는 이미 고속 주파수 도약이 수행된 것이며, 상기 Q-M개의 서브 캐리어들을 통해 송신되는 널 데이터들에 대해서는 전혀 고속 주파수 도약이 되어 있지 않은 상태이다.remind

3 is a matrix representing the operation of the controller 333 of FIG. 3, and as described above, the fast frequency hopping has already been performed on data transmitted through the M subcarriers among the output signals of the controller 333. There is no fast frequency hopping for null data transmitted on the QM subcarriers.

라고 칭하기로 하며, 상기 신호

은 하기 수학식 19와 같이 나타낼 수 있다.The IFFT unit 335 inputs the signal output from the controller 333 to perform a Q-point IFFT and outputs the same to the parallel / serial converter 337. Here, the signal output from the IFFT unit 335

And the signal

Can be expressed as in Equation 19 below.

The parallel / serial converter 337, the guard interval inserter 339, the digital / analog converter 341, and the RF processor 343 include the parallel / serial converter 131 of FIG. 1 and the guard interval insertion. Since the same operation as the device 133, the digital-to-analog converter 135, and the RF processor 137 is performed, detailed description thereof will be omitted.

In FIG. 3, the transmitter structure of the FFH-OFDM communication system performing the function in the second embodiment of the present invention has been described. Next, the function of the second embodiment of the present invention will be described with reference to FIG. The receiver structure of the FFH-OFDM communication system will be described.

4 is a block diagram showing a receiver structure of an FFH-OFDM communication system performing a function in the second embodiment of the present invention.

Referring to FIG. 4, the receiver includes an RF processor 411, an analog / digital converter 413, a channel estimator 415, a guard interval remover 417, a serial / parallel converter 419, An FFT device 421, a controller 423, an equalizer 425, an IFFT device 427, an equalizer 429, an FFT device 431, and a parallel / serial converter 433. do. In FIG. 4, the RF processor 411, the analog / digital converter 413, the guard interval remover 417, and the serial / parallel converter 419 are the RF processor 211 and the analog / Since the digital converter 213, the guard interval remover 217, and the serial / parallel converter 219 perform the same operations, detailed descriptions thereof will be omitted.

라고 칭하기로 하며, 상기 신호

는 시간 영역의 신호로서 하기 수학식 20과 같이 나타낼 수 있다.The signal output from the serial / parallel converter 419

And the signal

Is a signal in the time domain and can be expressed by Equation 20 below.

를 Q-포인트 FFT를 수행한 후 상기 제어기(423)로 출력한다. 여기서, 상기 FFT기(421)에서 출력하는 신호를

라고 칭하기로 하며, 상기 신호

는 주파수 영역의 신호로서 하기 수학식 21과 같이 나타낼 수 있다.The FFT unit 421 outputs a signal output from the serial / parallel converter 419.

Is output to the controller 423 after performing Q-point FFT. Here, the signal output from the FFT unit 421

And the signal

Is a signal in the frequency domain and can be represented by Equation 21 below.

에서 널 데이터, 일 예로 0이 포함되어 있는 Q-M개의 서브 캐리어 신호들을 제거하고 M개의 서브 캐리어들만을 상기 등화기(425)로 출력한다. 여기서, 상기 제어기(423)는 일종의 0 제거기(0 remover)로서 동작하는 것이며, 상기 제어기(423)의 동작은 상기 도 3의 제어기(333)에서 삽입한 0을 제거하는 것이다. Meanwhile, since data is included only in M subcarrier signals among the Q subcarrier signals output from the FFT unit 421, the controller 423 outputs the data from the FFT unit 421.

Removes QM subcarrier signals containing null data, for example 0, and outputs only M subcarriers to the equalizer 425. Here, the controller 423 operates as a kind of zero remover, and the operation of the controller 423 removes zeros inserted by the controller 333 of FIG. 3.

On the other hand, the operation of the controller 423 can be represented by the following equation (22).

Meanwhile, an equalization operation must be performed to compensate for distortion of the signal caused by the multipath channel. In the FFH-OFDM communication system, the equalization operation must be performed in both the time domain and the frequency domain. Therefore, the equalizer also needs two equalizers of the equalizer in the time domain to input the signals in the time domain and the equalizer in the frequency domain to input the signals in the frequency domain to perform the equalization operation. do.

Accordingly, the equalizer 425 equalizes the signal output from the controller 423 in the frequency domain and then outputs the equalized signal to the IFFT unit 427. The equalizer 425 compensates for the channel response in the frequency domain.

In addition, the IFFT unit 427 inputs the signal output from the equalizer 425 to perform an M-point IFFT and outputs the same to the equalizer 429. Here, since the IFFT unit 427 performs the same operation as the IFFT unit 321 of the transmitter of FIG. 3, a detailed description thereof will be omitted.

으로 정의하기로 하며, 상기 시간 영역에서의 등화 동작

은 하기 수학식 23과 같이 나타낼 수 있다.The equalizer 429 inputs the signal output from the IFFT unit 427, equalizes the signal in the time domain, and outputs the equalized signal to the FFT unit 431. Here, the equalization operation in the time domain

The equalization operation in the time domain

Can be expressed as in Equation 23 below.

은 상기 수학식 15에서 나타낸 바와 같은 행렬

의 허미시안

으로 표현되며, 따라서 상기 행렬

역시 대각 행렬이 되는 것이다.Equalization operation in the time domain as shown in Equation 23

Is a matrix as shown in Equation 15 above.

Hermitian of

Is represented by

It is also a diagonal matrix.

는 하기 수학식 24와 같이 나타낼 수 있다. 한편, 하기 수학식 24에서

는 상기 FFT기(431)에서 출력되어 상기 제어기(423)로 입력되는 신호로서,

,

,

,

,

각각은 차례로 상기 FFT기(431)와, 등화기(429)와, IFFT기(427)와, 등화기(425)와, 제어기(423)를 나타내는 행렬이다.The FFT unit 431 inputs the signal output from the equalizer 429 to perform an M-point FFT and then outputs it to the parallel / serial converter 433. Here, since the operation of the FFT device 431 is substantially the same as the operation of the FFT device 331 of FIG. 3, a detailed description thereof will be omitted. In addition, the signal output from the FFT unit 431, that is, the input data symbol estimation vector

Can be expressed as in Equation 24 below. On the other hand, in the following equation (24)

Is a signal output from the FFT unit 431 and input to the controller 423,

,

,

,

,

Each is in turn a matrix representing the FFT 431, equalizer 429, IFFT 427, equalizer 425, and controller 423.

The parallel / serial converter 433 serially converts the signal output from the FFT unit 431 and outputs the final input symbols.

In FIG. 4, the receiver structure of the FFH-OFDM communication system that performs the function in the second embodiment of the present invention has been described. Next, the function of the third embodiment of the present invention will be described with reference to FIG. The transmitter structure of the FFH-OFDM communication system will be described.

5 is a block diagram showing a transmitter structure of an FFH-OFDM communication system performing a function in the third embodiment of the present invention.

Referring to FIG. 5, the transmitter includes a serial / parallel converter 511, a controller 513, a high-speed frequency hop 520, an FFT device 531, a controller 533, and an IFFT device 535. ), A parallel / serial converter 537, a guard interval inserter 539, a digital / analog converter 541, and an RF processor 543. In addition, the high-speed frequency hop 520 is composed of an IFFT unit 521 and a linear processor 523.

First, when input data symbols to be transmitted are generated, the input data symbols are input to the serial / parallel converter 511. Herein, the data refers to a reference signal such as actual user data or a pilot, and according to the third embodiment of the present invention, a case in which fast frequency hopping is performed on only M subcarriers is performed. ) Converts the input data symbols into M symbols in parallel and outputs them to the controller 513. The controller 513 inputs a signal output from the serial / parallel converter 511, inserts null data, for example, 0 into QM subcarrier bands other than the M subcarrier bands, and then executes the IFFT. Output to the machine 521. Here, the controller 513 operates as a kind of zero inserter.

The IFFT unit 521 inputs a signal output from the controller 513, performs a Q-point IFFT, and outputs the result to the linear processor 523. The linear processor 523 inputs the signal output from the IFFT unit 521 and linearly processes the signal output from the IFFT unit 521 and outputs the linear signal to the FFT unit 531. Here, since the operations of the IFFT processor 521 and the linear processor 523 are the same as those of the IFFT processor 121 and the linear processor 123 of FIG. 1, detailed descriptions thereof will be omitted.

라고 칭하기로 하며, 상기 신호

는 데이터가 포함된 M개의 서브 캐리어 신호들과 널 데이터가 포함된 Q-M개의 서브 캐리어 신호들이 시간 영역에서 확산된 신호이다. The FFT unit 531 inputs a signal output from the linear processor 123 to perform a Q-point FFT and then outputs the signal to the controller 533. Here, the signal output from the FFT unit 531

And the signal

Is a signal obtained by spreading M subcarrier signals including data and QM subcarrier signals including null data in a time domain.

를 입력하여 Q-M개의 서브 캐리어들에 대응되도록 0을 삽입한 후 상기 IFFT기(535)로 출력한다. 여기서, 상기 제어기(533) 역시 일종의 0 삽입기로서 동작하는 것이며, 상기 제어기(533)의 0 삽입 동작은 하기 수학식 25와 같이 나타낼 수 있다.The controller 533 is a signal output from the FFT unit 531

0 is inserted to correspond to the QM subcarriers and then outputs to the IFFT unit 535. Here, the controller 533 also operates as a kind of zero inserter, and the zero insertion operation of the controller 533 can be expressed by Equation 25 below.

라고 칭하기로 하며, 상기 신호

은 하기 수학식 26과 같이 나타낼 수 있다. 한편, 하기 수학식 26에서

은 상기 제어기(513)로 입력되는 데이터 벡터를 나타내며,

,

,

,

,

,

각각은 차례로 상기 제어기(513)와, 상기 IFFT기(521)와, 선형 처리기(523)와, FFT기(531)와, 제어기(533)와, IFFT기(535)를 나타내는 행렬들이다. The IFFT unit 535 inputs the signal output from the controller 533 to perform a Q-point IFFT and then outputs it to the parallel / serial transformer 537. Here, the signal output from the IFFT unit 535

And the signal

Can be expressed as in Equation 26 below. Meanwhile, in Equation 26

Represents a data vector input to the controller 513,

,

,

,

,

,

Each of these is in turn a matrix representing the controller 513, the IFFT unit 521, the linear processor 523, the FFT unit 531, the controller 533, and the IFFT unit 535.

As shown in Equation 26, when the M subcarrier signals to which data is transmitted and the QM subcarrier signals to which null data are transmitted are added to generate a signal of size Q, the fast frequency hopping is performed. Since the number of subcarriers used in each configuration is fixed to Q, hardware transmitters can be configured in a stable manner regardless of the number M of subcarriers to which actual data is transmitted.

와 상기 수학식 26에 나타낸 바와 같은 송신 벡터

는 다음과 같은 2가지 조건들을 만족해야만 한다.On the other hand, the transmission vector as shown in equation (19)

And a transmission vector as shown in Equation 26 above

Must satisfy the following two conditions:

(1) First condition

와 송신 벡터

를 동일한 형태로 해주기 위해

의 엘리먼트들의 값들을 기반으로 하여

의 엘리먼트들의 값들을 설정해야만 한다. 상기 제1조건은 하기 수학식 27과 같이 나타낼 수 있다.Transmission vector

And transmit vector

To make the same form

Based on the values of the elements of

You must set the values of the elements of. The first condition may be expressed by Equation 27 below.

이 곱해지는 것이다.As described above, in the third embodiment of the present invention, since the signals transmitted through the QM subcarriers are replaced with null data, the above equation is used to have the same total energy as in the second embodiment of the present invention. In Eq 27

Is multiplied.

(2) Second condition

The second condition is a condition for ensuring that the transmission vectors transmitted in the second and third embodiments of the present invention are always the same value, and can be expressed by Equation 28 below.

The parallel / serial converter 537, the guard interval inserter 539, the digital / analog converter 541, and the RF processor 543 include the parallel / serial converter 131 of FIG. 1 and the guard interval insertion. Since the same operation as the device 133, the digital-to-analog converter 135, and the RF processor 137 is performed, detailed description thereof will be omitted.

In FIG. 5, the transmitter structure of the FFH-OFDM communication system performing the function in the third embodiment of the present invention has been described. Next, the function in the third embodiment of the present invention will be described with reference to FIG. The receiver structure of the FFH-OFDM communication system will be described.

6 is a block diagram showing a receiver structure of an FFH-OFDM communication system performing a function in the third embodiment of the present invention.

Referring to FIG. 6, the receiver includes an RF processor 611, an analog / digital converter 613, a channel estimator 615, a guard interval remover 617, a serial / parallel converter 619, FFT machine 621, controller 623, equalizer 625, IFFT machine 627, equalizer 629, FFT machine 631, controller 633, parallel / serial It consists of a transducer 635. In FIG. 6, the RF processor 611, the analog / digital converter 613, the guard interval remover 617, and the serial / parallel converter 619 are the RF processor 211 and the analog / Since the digital converter 213, the guard interval remover 217, and the serial / parallel converter 219 perform the same operations, detailed descriptions thereof will be omitted. In addition, since the FFT device 621 performs the same operation as the FFT device 421 described with reference to FIG. 4, a detailed description thereof will be omitted.

와 상기 FFT기(621)에서 출력하 는 신호

는 상기 수학식 20 및 수학식 21에서 설명한

와

와 동일한 신호이다. 그리고, 상기 도 5에서 설명한 송신기에서 실제 데이터를 송신하는 서브 캐리어들의 개수는 M개이므로 상기 주파수 영역의 신호

는 M개의 서브 캐리어 신호들에는 데이터가, 나머지 Q-M개의 서브 캐리어 신호들에는 잡음만 포함되어 있다. 따라서, 상기 제어기(623)는 상기 FFT기(621)에서 출력한 신호

에서 Q-M개의 서브 캐리어들에 해당하는 신호들을 제거하고 널 데이터, 일 예로 0을 삽입한 후 상기 등화기(625)로 출력한다. 여기서, 상기 제어기(623)는 일종이 0 삽입기로서, 상기 도 4에서 설명한 제어기(423)와 동일한 동작을 수행하므로 그 상세한 설명을 생략하기로 한다.On the other hand, the signal input to the FFT unit 621

And a signal output from the FFT unit 621

Is described in Equation 20 and Equation 21.

Wow

Is the same signal as In addition, since the number of subcarriers transmitting actual data in the transmitter described with reference to FIG. 5 is M, signals in the frequency domain

The M subcarrier signals contain data, and the remaining QM subcarrier signals contain only noise. Accordingly, the controller 623 outputs the signal output from the FFT unit 621.

Removes signals corresponding to the QM subcarriers, inserts null data, for example, 0, and outputs the same to the equalizer 625. Here, the controller 623 is a zero inserter, and performs the same operation as the controller 423 described with reference to FIG. 4, and thus a detailed description thereof will be omitted.

의 허미시안으로 정의되며 이는 하기 수학식 29와 같이 표현된다.The equalizer 625 inputs the signal output from the controller 623, equalizes the signal in the frequency domain, and outputs the equalized signal to the IFFT unit 627. The IFFT unit 627 inputs the signal output from the equalizer 625 to perform a Q-point IFFT and outputs the same to the equalizer 629. The equalizer 629 inputs the signal output from the IFFT device 627, equalizes the signal in the time domain, and outputs the equalized signal to the FFT device 631. Here, the equalizer 629 is a matrix of linear processor 623 of the transmitter of FIG.

It is defined as the Hermisian of and is represented by Equation 29 below.

The FFT 631 inputs the signal output from the equalizer 629 to perform a Q-point FFT and outputs the same to the controller 633. Since the number of subcarriers transmitting actual data is M, the controller 633 selects and outputs only signals corresponding to the M estimated data as shown in Equation 30 below. . Here, the controller 633 operates as a kind of selector.

The parallel / serial converter 635 serially converts the signal output from the FFT unit 633 and outputs the final input symbols.

As described above, since the transmission vectors transmitted by the transmitters of the second and third embodiments of the present invention are the same, the receiver of the third embodiment of the present invention may be used corresponding to the transmitter of the second embodiment of the present invention. Alternatively, the receiver of the second embodiment of the present invention may be used corresponding to the transmitter of the third embodiment of the present invention.

Meanwhile, in the second and third embodiments of the present invention, the operation of performing the fast frequency hopping on the assumption of transmitting data targeting only one user has been described. However, as in the OFDAM communication system, the downlink ( When the entire frequency band is divided and allocated to a plurality of users in a downlink channel, fast frequency hopping is performed for each of the plurality of users using some frequency bands as in the second and third embodiments of the present invention. There is a need for a transmitter and a receiver to perform this. In the fourth embodiment of the present invention, a method of performing a fast frequency hopping considering the plurality of users, that is, considering the multiple access will be proposed.

Next, an OFDMA communication system (hereinafter, referred to as a 'high frequency hopping OFDMA communication system') that performs a high frequency hopping in consideration of a plurality of users will be described with reference to FIG. 7.

7 is a block diagram illustrating a transmitter structure of a fast frequency hopping OFDMA communication system performing a function in the fourth embodiment of the present invention.

Referring to FIG. 7, the transmitter includes a fast frequency hopping / OFDM processing unit 710, a multiplexer 720, an IFFT unit 730, a parallel / serial converter 740, and a guard interval insertion. Device 750, a digital-to-analog converter 760, and an RF processor 770. In addition, the fast frequency hopping / OFDM processing unit 710 may include a plurality of fast frequency hopping / OFDM processors 711-1 to 1st to process data targeting a first user. And a k-th fast frequency hopping / OFDM processor 711-K for processing data targeting K users.

내지

라고 가정하기로 한다. 상기 데이터

는 상기 제1고속 주파수 도약/OFDM 처리기(711-1)로, 이런 식으로 상기 데이터

는 상기 제K고속 주파수 도약/OFDM 처리기(711-K)로 입력된다. First, it is assumed that the number of subcarriers allocated to the first to K-th users is M ₁ to M _K , and data to be transmitted to the first to K-th users is determined.

To

Let's assume. The data

Is the first fast frequency hopping / OFDM processor 711-1, in this way the data.

Is input to the K-th fast frequency hopping / OFDM processor 711-K.

내지

를 출력한다. 일 예로, 상기 제K고속 주파수 도약/OFDM 처리기(711-K)가 본 발명의 제2실시예와 같은 방식으로 고속 주파수 도약 및 OFDM 변조를 수행할 경우 도 3의 제어기(333)에서 출력하는 신호중 실제 사용하는 서브 캐리어들의 개수인 M_k 개의 엘리먼트들이

가 되는 것이며, 이와는 달리 상기 제K고속 주파수 도약/OFDM 처리기(711-K)가 본 발명의 제3실시예와 같은 방식으로 고속 주파수 도약 및 OFDM 변조를 수행할 경우 도 5의 제어기(533)에서 출력하는 신호중 실제 사용하는 서브 캐리어들의 개수인 M_k 개의 엘리먼트들이

가 되는 것이다.The first high speed frequency hopping / OFDM processor 711-1 to the Kth high frequency hopping / OFDM processor 711-K are performed in the same manner as described in the second or third embodiment of the present invention. Modulated Signal After Performing OFDM Modulation

To

Outputs For example, when the K-th fast frequency hopping / OFDM processor 711-K performs fast frequency hopping and OFDM modulation in the same manner as the second embodiment of the present invention, among the signals output from the controller 333 of FIG. M _k elements, the number of subcarriers actually used,

In contrast, when the K-th fast frequency hopping / OFDM processor 711-K performs fast frequency hopping and OFDM modulation in the same manner as in the third embodiment of the present invention, the controller 533 of FIG. M _k elements, which is the number of subcarriers actually used,

To be.

내지

는 상기 다중화기(720)로 입력되고, 상기 다중화기(720)는 어떤 사용자에게도 할당되지 않은

에 해당하는 서브 캐리어 신호들에 0을 삽입한 후 상기 IFFT기(730)로 출력한다. 상기 IFFT기(730)는 상기 다중화기(720)에서 출력한 신호를 입력하여 Q-포인트 IFFT를 수행한 후 상기 병렬/직렬 변환기(740)로 출력한다. 상기 병렬/직렬 변환기(740)와, 보호 구간 삽입기(750)와, 디지털/아날로그 변환기(760)와, RF 처리기(770)는 상기 도 1의 병렬/직렬 변환기(131)와, 보호 구간 삽입기(133)와, 디지털/아날로그 변환기(135)와, RF 처리기(137)과 동일한 동작을 수행하므로 여기서는 그 상세한 설명을 생략하기로 한다. 또한 도 7은 송신기에서 여러 사용자를 신호를 함께 다중화(multiplexing)하여 전송하는 반면, 수신기에서는 이와 상관없이 항상 자기 신호만 복조하므로 별도의 구현을 필요로 하지 않고 상기 본 발명의 제2실시예 또는 제3실시예에서 설명한 수신기를 사용할 수 있다.Signals output from the first fast frequency hopping / OFDM processor 711-1 through K-th fast frequency hopping / OFDM processor 711-K

To

Is input to the multiplexer 720, and the multiplexer 720 is not assigned to any user.

0 is inserted into the subcarrier signals corresponding to the subcarrier signal and then output to the IFFT unit 730. The IFFT unit 730 inputs the signal output from the multiplexer 720 to perform a Q-point IFFT and then outputs it to the parallel / serial converter 740. The parallel / serial converter 740, the guard interval inserter 750, the digital / analog converter 760, and the RF processor 770 include the parallel / serial converter 131 of FIG. 1 and the guard interval insertion. Since the same operation as the device 133, the digital-to-analog converter 135, and the RF processor 137 is performed, detailed description thereof will be omitted. In addition, while FIG. 7 transmits multiple users by multiplexing signals together in a transmitter, the receiver always demodulates only a magnetic signal irrespective of this and thus does not require a separate implementation. The receiver described in the third embodiment can be used.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, the present invention has the advantage of enabling fast frequency hopping in an OFDM communication system so that frequency diversity gain can be obtained even within one OFDM symbol time, thereby improving system performance. In addition, the present invention enables the fast frequency hopping scheme to be applied not only to all frequency bands but also to some frequency bands in the OFDM communication system, so that the DCA scheme or the guard band may be used for the OFDM communication system. It is possible to apply the frequency hopping method to improve the system performance.

Claims (45)

Fast Frequency Hopping-Orthogonal Frequency Division (FFH-OFDM), which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. In the signal transmission apparatus of a multiplexing communication system, A fast frequency hopping device that corresponds to input data in a one-to-one correspondence with a preset number of subcarriers to transmit the input data among the plurality of subcarriers, and then performs a fast frequency hopping according to a preset fast frequency hopping pattern. Wow, A fast Fourier transformer for fast Fourier transforming the fast frequency honed signal; A controller for inserting null data into subcarriers except the set number of subcarriers; A first inverse fast Fourier transformer for inputting subcarrier signals other than the set number of subcarrier signals with the fast Fourier transform and the set number of subcarriers with the null data inserted thereinto; And a transmitter for transmitting an inverse fast Fourier transformed signal in the first inverse fast Fourier transformer. The method of claim 1, The fast frequency hopping device; A second inverse fast Fourier transformer corresponding to the input data to the set number of subcarriers one to one and inverse fast Fourier transform; And a linear processor which linearly processes the second inverse fast Fourier transformer to have a predetermined gain on inverse fast Fourier transformed subcarrier signals. The method of claim 2, The fast frequency hopping device has a fast frequency hopping matrix as shown in Equation 31 below.

The apparatus according to claim 1, wherein the fast frequency hopping is performed correspondingly.

In Equation 31, n represents a sample index, m represents a sub-channel index,

Denotes a subcarrier on which data of the mth subchannel is transmitted in an nth sample, and M denotes a predetermined number of some subcarriers among all Q subcarriers used in the FFH-OFDM communication system. The method of claim 3, The second inverse fast Fourier transformer is an inverse fast Fourier transform matrix of the M-point inverse fast Fourier transform device

And inverse fast Fourier transform the subcarrier signals corresponding to the M subcarriers one-to-one corresponding to the M subcarriers.

The method of claim 4, wherein The linear processor; And when the fast frequency hopping pattern is a cyclic fast frequency hopping pattern, the second inverse fast Fourier transformer multiplies inverse fast Fourier transformed subcarrier signals by a predetermined diagonal matrix to perform linear processing. The method of claim 5, The linear processor is a matrix such as

And inversely processing inverse fast Fourier transformed subcarrier signals in the second inverse fast Fourier transformer.

In Equation 33,

Is the inverse fast Fourier transform matrix

Represents the Hermisian of. The method of claim 6, Wherein the cyclic fast frequency hopping pattern is a fast frequency hopping pattern defined by Equation 34 below.

In Equation 34, f _n represents a subcarrier on which data of a first subchannel is transmitted in an nth sample. Fast Frequency Hopping-Orthogonal Frequency Division Multiplexing (OFDM) communication, which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. In the signal transmission method of the system, Associating input data with one-to-one correspondence with a predetermined number of subcarriers to transmit the input data among the plurality of subcarriers, and then performing a fast frequency hopping corresponding to a preset high frequency hopping pattern; Fast Fourier transforming the fast frequency hopping signal; Inserting null data into subcarriers except the set number of subcarriers; Inverse fast Fourier transform by inputting subcarrier signals other than the set number of subcarrier signals with the fast Fourier transform and the set number of subcarriers into which the null data is inserted; And transmitting the inverse fast Fourier transformed signal. The method of claim 8, Performing the fast frequency hopping; A first process of corresponding the input data to the set number of subcarriers one-to-one and then performing an inverse fast Fourier transform; And a second process of linearly processing the subcarrier signals inversely fast Fourier transformed to have a predetermined gain. The method of claim 9, The fast frequency hopping process is a fast frequency hopping matrix such as

The method according to claim 1, characterized in that performed according to.

In Equation 35, n represents a sample index, m represents a sub-channel index,

Denotes a subcarrier on which data of the mth subchannel is transmitted in an nth sample, and M denotes a predetermined number of some subcarriers among all Q subcarriers used in the FFH-OFDM communication system. The method of claim 10, The first process is the M-point inverse fast Fourier transform matrix

And inverse fast Fourier transform the subcarrier signals corresponding to the M subcarriers one-to-one corresponding to the M subcarriers.

The method of claim 11, The second process is to perform linear processing by multiplying the inverse fast Fourier transform subcarrier signals in a first diagonal matrix by a predetermined diagonal matrix when the fast frequency hopping pattern is a cyclic fast frequency hopping pattern. The method of claim 12, Wherein the cyclic fast frequency hopping pattern is a fast frequency hopping pattern defined by Equation 37 below.

In Equation 37, f _n represents a subcarrier on which data of a first subchannel is transmitted in an nth sample. Fast Frequency Hopping-Orthogonal Frequency Division (FFH-OFDM), which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. In the signal receiving apparatus of a multiplexing communication system, A first fast Fourier transformer for converting a received signal to a fast Fourier transform, In the fast Fourier transformed signal in the first fast Fourier transformer, a transmitter removes signals corresponding to remaining subcarriers except for a preset number of subcarriers to which data is transmitted among the plurality of subcarriers, A controller for inserting null data to correspond to the subcarriers; A first equalizer for equalizing an output signal of the controller in a frequency domain; An inverse fast Fourier transformer for inverse fast Fourier transform the equalized signal in the frequency domain corresponding to the fast frequency hopping matrix applied by the transmitter; A second equalizer for equalizing the inverse fast Fourier transform signal in a time domain; And a second fast Fourier transformer for fast Fourier transforming the equalized signal in the time domain. The method of claim 14, And the fast frequency hopping matrix is expressed as Equation 38 below.

In Equation 38,

Denotes the fast frequency hopping matrix, n denotes a sample index, m denotes a sub-channel index,

Denotes a subcarrier on which data of the mth subchannel is transmitted in an nth sample, and M denotes a predetermined number of some subcarriers among all Q subcarriers used in the FFH-OFDM communication system. The method of claim 15, And the second equalizer multiplies the inverse fast Fourier transformed subcarrier signals by a Hermisian of a preset diagonal matrix when the fast frequency hopping pattern corresponding to the fast frequency hopping matrix is a cyclic fast frequency hopping pattern. Said device. The method of claim 16, Wherein the cyclic fast frequency hopping pattern is a fast frequency hopping pattern defined by Equation 39 below.

In Equation 39, f _n represents a subcarrier on which data of a first subchannel is transmitted in an nth sample. Fast Frequency Hopping-Orthogonal Frequency Division (FFH-OFDM), which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. In the signal reception method of a multiplexing communication system, A first process of performing fast Fourier transform on the received signal, The signals corresponding to the remaining subcarriers are removed from the fast Fourier transformed signal in the first process except for a preset number of subcarriers, from which the transmitting apparatus transmits data among the plurality of subcarriers, and the remaining subcarriers are removed. A second process of inserting null data so as to correspond to the field; A third process of equalizing the signal generated in the second process in a frequency domain; A fourth process of inverse fast Fourier transforming the equalized signal in the frequency domain; A fifth process of equalizing the inverse fast Fourier transform signal in a time domain; And a sixth process of fast Fourier transforming the equalized signal in the time domain. The method of claim 18, The fast frequency hopping matrix is represented by Equation 40 below.

In Equation 40,

Denotes the fast frequency hopping matrix, n denotes a sample index, m denotes a sub-channel index,

Denotes a subcarrier on which data of the mth subchannel is transmitted in an nth sample, and M denotes a predetermined number of some subcarriers among all Q subcarriers used in the FFH-OFDM communication system. The method of claim 19, In the fifth step, when the fast frequency hopping pattern corresponding to the fast frequency hopping matrix is a cyclic fast frequency hopping pattern, the inverse fast Fourier transformed subcarrier signals are multiplied by the Hermian of a preset diagonal matrix. Said method. The method of claim 20, Wherein the cyclic fast frequency hopping pattern is a fast frequency hopping pattern defined by Equation 42.

In Equation 41, f _n represents a subcarrier on which data of a first subchannel is transmitted in an nth sample. Fast Frequency Hopping-Orthogonal Frequency Division (FFH-OFDM), which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. In the signal transmission apparatus of a multiplexing communication system, A first controller for inserting null data into subcarriers except for a predetermined number of subcarriers to transmit the input data of the plurality of subcarriers; High speed inputting the input data to have a one-to-one correspondence to the set number of subcarriers, and inputs the sub-carrier signals with null data inserted in the first controller to perform a fast frequency hopping corresponding to the preset high-speed hopping pattern With frequency hopping, A fast Fourier transformer for fast Fourier transforming the fast frequency honed signal; A second controller for inserting null data into subcarriers other than the set number of subcarriers in the fast Fourier transformed signal; A first inverse fast Fourier transformer for inputting subcarrier signals other than the set number of subcarrier signals converted from the fast Fourier transform and the set number of subcarriers into which the null data is inserted by the second controller; And a transmitter for transmitting an inverse fast Fourier transformed signal in the first inverse fast Fourier transformer. The method of claim 22, The fast frequency hopping device; A second inverse fast Fourier transformer for inverse fast Fourier transforming the signal output from the first controller; And a linear processor which linearly processes the second inverse fast Fourier transformer to have a predetermined gain on inverse fast Fourier transformed subcarrier signals. The method of claim 23, wherein The fast frequency hopping device has a fast frequency hopping matrix such as

The apparatus according to claim 1, wherein the fast frequency hopping is performed correspondingly.

In Equation 42, n represents a sample index, m represents a sub-channel index,

Denotes a subcarrier on which data of the mth subchannel is transmitted in an nth sample, and Q denotes the total number of subcarriers. The method of claim 24, The second inverse fast Fourier transformer is an inverse fast Fourier transform matrix of the Q-point inverse fast Fourier transform of Equation 43

And inverse fast Fourier transform one-to-one corresponding subcarrier signals to the Q subcarriers corresponding to the inverse fast Fourier transforms.

The method of claim 25, The linear processor; And when the fast frequency hopping pattern is a cyclic fast frequency hopping pattern, the second inverse fast Fourier transformer multiplies inverse fast Fourier transformed subcarrier signals by a predetermined diagonal matrix to perform linear processing. The method of claim 26, Wherein the cyclic fast frequency hopping pattern is a fast frequency hopping pattern defined by Equation 44 below.

In Equation 44, f _n represents a subcarrier on which data of a first subchannel is transmitted in an nth sample. The method of claim 27, And wherein said diagonal matrix satisfies the following conditions.

In Equation 45, M represents the set number,

Represents the diagonal matrix,

Denotes the diagonal matrix when fast frequency hopping is performed without inserting null data into subcarriers except the set number of subcarriers in the first step.

Fast Frequency Hopping-Orthogonal Frequency Division (FFH-OFDM), which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. In the signal transmission method of a multiplexing communication system, Inserting null data into subcarriers except for a preset number of subcarriers to transmit the input data among the plurality of subcarriers; Inputting the input data in a one-to-one correspondence to the set number of subcarriers, and inputting the subcarrier signals into which null data is inserted in the first step to perform a fast frequency hopping in accordance with a preset fast frequency hopping pattern. 2 courses, A third step of performing fast Fourier transform on the fast frequency hopping signal; Inserting null data into subcarriers other than the set number of subcarriers in the fast Fourier transformed signal; A fifth process of inputting inverse fast Fourier transform by inputting subcarrier signals of the set number of fast Fourier transforms and subcarriers other than the set number of subcarriers into which null data is inserted in a fourth process; And a sixth step of transmitting an inverse fast Fourier transformed signal in the fifth step. The method of claim 29, The second process is; A seventh process of performing inverse fast Fourier transform on the signal generated in the first process; And an eighth process of performing linear processing to have a predetermined gain on the inverse fast Fourier transformed subcarrier signals in the seventh process. The method of claim 30, The second process is a fast frequency hopping matrix such as

And performing a fast frequency hopping correspondingly.

In Equation 47, n represents a sample index, m represents a sub-channel index,

Denotes a subcarrier on which data of the mth subchannel is transmitted in an nth sample, and Q denotes the total number of subcarriers. The method of claim 31, wherein The seventh process is the Q-point inverse fast Fourier transform matrix

And inverse fast Fourier transform one-to-one corresponding subcarrier signals to the Q subcarriers.

33. The method of claim 32, And the eighth process is to perform linear processing by multiplying the inverse fast Fourier transformed subcarrier signals by a predetermined diagonal matrix when the fast frequency hopping pattern is a cyclic fast frequency hopping pattern. The method of claim 33, wherein Wherein the cyclic fast frequency hopping pattern is a fast frequency hopping pattern defined by Equation 49 below.

In Equation 49, f _n represents a subcarrier on which data of a first subchannel is transmitted in an nth sample. The method of claim 34, wherein Wherein the diagonal matrix satisfies the conditions of Equation 50 and Equation 51 below.

In Equation 50, M represents the set number,

Represents the diagonal matrix,

Denotes the diagonal matrix when fast frequency hopping is performed without inserting null data into subcarriers except the set number of subcarriers in the first step.

Fast Frequency Hopping-Orthogonal Frequency Division (FFH-OFDM), which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. In the signal receiving apparatus of a multiplexing communication system, A first fast Fourier transformer for converting a received signal to a fast Fourier transform, In the fast Fourier transformed signal in the first fast Fourier transformer, a transmitter removes signals corresponding to remaining subcarriers except for a preset number of subcarriers to which data is transmitted among the plurality of subcarriers, A first controller for inserting null data to correspond to the subcarriers; A first equalizer for equalizing an output signal of the first controller in a frequency domain; An inverse fast Fourier transformer for inverse fast Fourier transform of the equalized signal in the frequency domain; A second equalizer for equalizing the inverse fast Fourier transform signal in a time domain; A second fast Fourier transformer for fast Fourier transforming the equalized signal in the time domain; And a second controller for removing signals corresponding to the remaining subcarriers from the fast Fourier transformed signal by the second fast Fourier transformer and inserting null data to correspond to the remaining subcarriers. Device. The method of claim 36, And the fast frequency hopping matrix is expressed as Equation 52 below.

In Equation 52,

Denotes the fast frequency hopping matrix, n denotes a sample index, m denotes a sub-channel index,

Denotes a subcarrier on which data of the mth subchannel is transmitted in an nth sample, and Q denotes the total number of subcarriers. The method of claim 37, And the second equalizer multiplies the inverse fast Fourier transformed subcarrier signals by a Hermisian of a preset diagonal matrix when the fast frequency hopping pattern corresponding to the fast frequency hopping matrix is a cyclic fast frequency hopping pattern. Said device. The method of claim 38, Wherein the cyclic fast frequency hopping pattern is a fast frequency hopping pattern defined by Equation 53 below.

In Equation 53, f _n represents a subcarrier on which data of a first subchannel is transmitted in an nth sample. The method of claim 39, Wherein the diagonal matrix satisfies a condition as in Equation 54 and Equation 55 below.

In Equation 54, M represents the set number,

Represents the diagonal matrix,

Denotes the diagonal matrix when fast frequency hopping is performed without inserting null data into subcarriers except the set number of subcarriers in the first step.

Fast Frequency Hopping-Orthogonal Frequency Division Multiplexing (OFDM) communication, which divides the entire frequency band into a plurality of subcarrier bands and has a plurality of subchannels that are a set of at least one subcarrier bands. In the receiving method of the system, A first process of performing fast Fourier transform on the received signal, The signals corresponding to the remaining subcarriers are removed from the fast Fourier transformed signal in the first process except for a preset number of subcarriers, from which the transmitting apparatus transmits data among the plurality of subcarriers, and the remaining subcarriers are removed. A second process of inserting null data so as to correspond to the field; A third process of equalizing the signal generated in the second process in a frequency domain; A fourth process of inverse fast Fourier transforming the equalized signal in the frequency domain; A fifth process of equalizing the inverse fast Fourier transform signal in a time domain; A sixth process of fast Fourier transforming the equalized signal in the time domain; And a seventh step of removing signals corresponding to the remaining subcarriers from the fast Fourier transformed signal in the sixth step and inserting null data to correspond to the remaining subcarriers. The method of claim 41, wherein The fast frequency hopping matrix is represented by Equation 56 below.

In Equation 56,

Denotes the fast frequency hopping matrix, n denotes a sample index, m denotes a sub-channel index,

Denotes a subcarrier on which data of the mth subchannel is transmitted in an nth sample, and Q denotes the total number of subcarriers. The method of claim 42, wherein In the fifth process, when the fast frequency hopping pattern corresponding to the fast frequency hopping matrix is a cyclic fast frequency hopping pattern, the inverse fast Fourier transformed subcarrier signals are multiplied by a Hermithian of a preset diagonal matrix. Said method. The method of claim 43, Wherein the cyclic fast frequency hopping pattern is a fast frequency hopping pattern defined by Equation 57 below.

In Equation 57, f _n represents a subcarrier on which data of a first subchannel is transmitted in an nth sample. The method of claim 44, Wherein the diagonal matrix satisfies a condition as in Equation 58 and Equation 59 below.

In Equation 58, M represents the set number,

Represents the diagonal matrix,

Denotes the diagonal matrix when fast frequency hopping is performed without inserting null data into subcarriers except the set number of subcarriers in the first step.

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