KR20190005467A - Method and apparatus for encrypted communication based on ftn - Google Patents

Abstract

Disclosed are a method and an apparatus for encrypted communication based on faster-than-Nyquist (FTN). A transmission apparatus generates an encrypted signal using the interference generated when an FTN signal is generated. In the process of generating the FTN signal, a parameter defined by an encryption code is used instead of that with a fixed value, for the interval between the symbols or the pulse shaping. By using the parameter defined by the encryption code, the interval between the symbols or the pulse shaping is variably set. With the variable setting, only a receiving apparatus that knows the encryption code used in generating the FTN signal can perform processing on the FTN signal.

Description

[0001] METHOD AND APPARATUS FOR ENCRYPTED COMMUNICATION BASED ON FTN [0002]

The following embodiments relate to a method and apparatus for providing FTN communication, and more particularly to a method and apparatus for providing encrypted communication based on FTN.

The Nyquist transmission scheme used in existing broadcasting systems and communication systems is based on inter-symbol interference (ICI) interference within a given bandwidth. ISI) of the pulse shaping and the rate of transmission for transmitting the signal.

That is to say, the Nyquist pulse shaping method is a pulse shaping method that provides the maximum transmission rate in a given bandwidth without interference between symbols.

In a system using a Nyquist transmission scheme, a method used to improve a transmission rate includes a method of reducing a pulse shaping period and a method of increasing a symbol modulation level.

However, if the pulse shaping period is reduced, the system bandwidth increases, and as the symbol modulation level increases, more signal-to-noise ratio (SNR) is required for signal detection of the same level.

In recent years, there is an increasing demand for increasing the frequency efficiency in a communication system. The Nyquist pulse shaping method has limitations in terms of transmission efficiency. To overcome the limitations of existing transmission schemes such as Nyquist transmission schemes, Faster-Than-Nyquist (Faster-Than-Nyquist), which can improve the transmission rate without using a higher modulation level within a specified bandwidth ; FTN) transmission method.

The FTN transmission method is a method of transmitting a signal in a shorter pulse forming period while maintaining the shape of the pulse shaping given according to the bandwidth.

When a signal is transmitted using the FTN transmission scheme, pulses are superimposed because the intervals between symbols are narrowed, and inter-symbol-interference (ISI) is inevitably generated in the transmission signal. The ISI generated by the FTN transmission scheme is referred to as " FTN interference ". Such FTN interference degrades signal detection performance.

Thus, the FTN transmission scheme can improve the transmission rate, but the ISI that does not occur in the Nyquist transmission scheme is included in the signal. Therefore, the receiver must cancel the FTN interference in order to recover the data without error. At this time, if the pattern of FTN interference is already known, the receiver can recover the original signal using various cancellation methods.

As a method for eliminating FTN interference, a method of repeatedly performing interference cancellation and channel decoding through interworking of interference cancellation and channel decoding units can be considered. This method improves the performance of the channel code by eliminating the interference of the received signal sequence and repeatedly improves the performance by using the channel decoded sequence to cancel the interference again. . A method of using channel-decoded signal sequences for interference cancellation, comprising: a method of reflecting a prior probability of a received symbol sequence according to a configuration of interference cancellation; a method of estimating FTN interference from a decoded signal sequence; And a method of eliminating the FTN interference can be considered.

U.S. Patent Nos. 2016-0269049 and 2016-0218908 have been proposed in connection with FTN.

One embodiment may provide an apparatus and method for generating an encrypted signal using interference that occurs upon generation of an FTN signal.

One embodiment may provide an apparatus and method that uses a parameter defined by an encryption code, rather than a parameter of a fixed value, for the spacing or pulse shaping between symbols in the process of generating an FTN signal.

One embodiment may provide an apparatus and method for variably setting the spacing or pulse shaping between symbols of an FTN signal using parameters defined as an encryption code.

One embodiment provides an apparatus and method for enabling a receiving device to receive an FTN signal only when the receiving device knows the encryption code used in generating the FTN signal by variably setting the spacing or pulse shaping between the symbols of the FTN signal .

One embodiment may provide an apparatus and method for transmitting an encrypted signal using an interference pattern between predetermined symbols.

One embodiment may provide an apparatus and method that makes it possible to recover a transmitted symbol from a received encrypted signal only if the same interference pattern as the interference pattern used for encrypting the signal is applied.

One embodiment may provide an apparatus and method for allowing only authorized receiving devices having an encryption code to remove FTN interference and receive signals.

One embodiment can provide an apparatus and method for enhancing security as well as transmission efficiency by allowing an authorized receiving device having an encryption code to receive signals.

A method of modulating an input symbol stream using encryption information, the method comprising: generating divided symbol streams by dividing the input symbol stream; Generating pre-pulse shaped symbol streams by performing linear pulse shaping on the divided symbol streams; Generating fast Fourier transformed symbol sequences by applying Fast Fourier Transform (FFT) on the pre-pulse-formed symbol sequences; Generating truncated symbol streams by performing truncation on the fast Fourier transformed symbol streams; And generating a multiplexed symbol stream by performing multiplexing on the truncated symbol streams, the method comprising: dividing the divided symbol streams, the pre-pulse formed symbol streams, the fast Fourier transformed symbol streams , Wherein at least one of the truncated symbol streams is generated based on encryption information.

The encryption information may include first encryption information.

The first encryption information may indicate a scheme of dividing the input symbol stream.

The encryption information may include a first encryption code.

The first encryption code may represent the lengths of the divided symbol streams.

Each of the elements of the first encryption code may be a power of two.

The encryption information may include a first encryption code and a second encryption code.

The pre-pulse shaping may be performed by Faster-Than-Nyquist (FTN) mappers.

The FTN parameters of the FTN mappers may be determined based on the first encryption code and the second encryption code.

The FTN parameter may include a sampling time control variable of the FTN.

The sampling time control parameter of the m-th FTN mapper among the FTN mappers may be a value obtained by dividing the m-th element of the second encryption code by the m-th element of the first encryption code.

m may be an integer of 1 or more.

The sampling time control parameter of the m-th FTN mapper may be a m-th divided symbol stream of the divided symbol streams and a m-th truncated symbol stream of the truncated symbol streams.

The encryption information may include a first encryption code.

The first encryption code may indicate the length of the FFT.

The encryption information may include a second encryption code.

The second encryption code may represent the lengths of the truncated symbol streams.

The method of modulating the symbol stream may further include generating an interleaved symbol stream by performing interleaving on the multiplexed symbol stream.

An apparatus for modulating an input symbol stream using encryption information, the apparatus comprising: a demultiplexer for generating divided symbol streams by dividing the input symbol stream; FTN mappers for generating pre-pulse shaped symbol streams by performing linear pulse shaping on the divided symbol streams; FFT units for generating the fast Fourier transformed symbol streams by applying Fast Fourier Transform (FFT) to the pre-pulse-formed symbol streams; Cutoffs for generating truncated symbol streams by performing truncation on the fast Fourier transformed symbol streams; And a multiplexer for generating a multiplexed symbol stream by performing multiplexing with respect to the truncated symbol streams, wherein the demultiplexed symbol streams, the pre-pulse shaped symbol streams, the fast Fourier transformed symbol stream , At least one of the truncated symbol streams is generated based on the encryption information.

In another aspect, there is provided a method of demodulating an input symbol stream using encryption information, the method comprising: generating divided symbol streams by dividing an input symbol stream; Generating length-adjusted symbol streams by inserting at least one " 0 " in each of the divided symbol streams; Generating inverse fast Fourier transformed symbol sequences by applying Inverse Fast Fourier Transform (IFFT) on the length-adjusted symbol streams; Generating FTN interference canceled symbol sequences by removing FTN interference in each of the inverse fast Fourier transformed symbol sequences; And generating a multiplexed symbol stream by performing multiplexing on the symbol streams with FTN interference removed, wherein the step of generating the multiplexed symbol stream, the length-adjusted symbol streams, the inverse fast Fourier transformed symbol Wherein at least one of the columns and the FTN interference canceled symbol streams are generated based on the encryption information.

The method of demodulating the symbol stream may further include generating a deinterleaved symbol stream by performing deinterleaving on the preprocessed symbol stream.

The deinterleaved symbol stream may be the input symbol stream.

The encryption information may include second encryption information.

The second encryption information may indicate a scheme of dividing the input symbol stream.

The encryption information may include a second encryption code.

The second encryption code may represent the lengths of the divided symbol streams.

The encryption information may include first encryption information.

The first encryption information may determine the number of at least one " 0 " inserted in each of the divided symbol streams.

The encryption information may include a first encryption code.

The number of at least one " 0 " inserted into the mth divided symbol stream among the divided symbol streams may be a difference between lengths of the mth element and the mth divided symbol stream of the first encryption code.

The encryption information may include a first encryption code.

The first encryption code may indicate the length of the IFFT.

Each of the elements of the first encryption code may be a power of two.

The FTN interference may be a cyclic convolution of the first filter coefficient and the second filter coefficient.

The first filter coefficient may be a filter coefficient of an FTN mapper used in modulation of the input symbol stream.

The second filter coefficient may be a filter coefficient obtained by IFFT transform of the rectangular window of the cut used in the modulation of the input symbol stream.

In addition, there is further provided another method, apparatus, system for implementing the invention and a computer readable recording medium for recording a computer program for executing the method.

An apparatus and method are provided for generating an encrypted signal using interference that occurs upon generation of an FTN signal.

In the process of generating an FTN signal, an apparatus and method are provided for using a parameter defined by an encryption code, rather than a parameter of a fixed value, for interval or pulse shaping between symbols.

An apparatus and method for variably setting the spacing or pulse shaping between symbols of an FTN signal using parameters defined as an encryption code are provided.

There is provided an apparatus and method for enabling an FTN signal to be received only when the receiving apparatus knows the encryption code used in generating the FTN signal by variably setting the interval or pulse shaping between the symbols of the FTN signal.

An apparatus and method for transmitting an encrypted signal using interference patterns between predetermined symbols are provided.

There is provided an apparatus and method enabling to restore a transmission symbol from a received encrypted signal only when the same interference pattern as the interference pattern used for encryption of the signal is applied.

There is provided an apparatus and method for allowing only an authorized receiving apparatus having an encryption code to remove FTN interference and receive a signal.

There is provided an apparatus and a method for enhancing not only transmission efficiency but also security by enabling only an authorized receiving apparatus having an encryption code to receive a signal.

1 shows a structure of a modulation unit according to an embodiment.
2 is a flowchart of a modulation method according to an embodiment.
3 shows a structure of a demodulation unit according to an embodiment.
4 is a flowchart of a demodulation method according to an embodiment.
5 and 6 show an OFDM transmitting apparatus and an OFDM receiving apparatus of an OFDM communication system using a method of modulating an encrypted signal based on FTN according to an embodiment, respectively.
5 is a structural diagram of an OFDM transmitting apparatus using a method of modulating an encrypted signal based on FTN according to an embodiment.
6 is a structural diagram of an OFDM receiving apparatus using a method of demodulating an encrypted signal based on FTN according to an embodiment.
7 is a flow diagram of a method for transmitting an encrypted signal based on an FTN according to one embodiment.
8 is a flow diagram of a method of receiving an encrypted signal based on an FTN according to one embodiment.
9 illustrates an electronic device implementing a transmitting device according to one embodiment.
10 illustrates an electronic device implementing a receiving device according to one embodiment.

The following detailed description of exemplary embodiments refers to the accompanying drawings, which illustrate, by way of illustration, specific embodiments. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments. It should be understood that the various embodiments are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the location or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the embodiments. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the exemplary embodiments is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained.

In the drawings, like reference numerals refer to the same or similar functions throughout the several views. The shape and size of the elements in the figures may be exaggerated for clarity.

The terms used in the examples are intended to illustrate the embodiments and are not intended to limit the invention. In the examples, the singular includes the plural unless otherwise stated in the specification. It is noted that the terms "comprises" and / or "comprising" used in the specification are intended to be inclusive in a manner similar to the components, steps, operations, and / And that additional configurations may be encompassed within the scope of the embodiments of the exemplary embodiments or the technical ideas of the exemplary embodiments. When it is mentioned that a component is " connected " or " connected " to another component, the two components may be directly connected or connected to each other, It is to be understood that other components may be present in the middle of the components.

The terms first and second, etc. may be used to describe various components, but the components should not be limited by the terms above. The above terms are used to distinguish one component from another. For example, without departing from the scope of the right, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

In addition, the components shown in the embodiments are shown independently to represent different characteristic functions, which does not mean that each component is composed of separate hardware or one software constituent unit. That is, each component is listed as each component for convenience of explanation. For example, at least two of the components may be combined into a single component. Also, one component can be divided into a plurality of components. The integrated embodiments and the separate embodiments of each of these components are also included in the scope of the right without departing from the essence.

Also, some components are not essential components to perform essential functions, but may be optional components only to improve performance. Embodiments may be implemented only with components that are essential to implementing the essentials of the embodiments, and structures within which the optional components are excluded, such as, for example, components used only for performance enhancement, are also included in the scope of the right.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to facilitate embodiments of the present invention by those skilled in the art. In the following description of the embodiments, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present disclosure rather unclear.

In order for the receiver to eliminate FTN interference, it is necessary for the receiver to be informed of how narrow the spacing between the symbols in generating the signal. If the receiver does not know the degree to which the interval between symbols is narrowed, it may be difficult to recover the data correctly. In particular, if the spacing between symbols is not constant and the FTN signal is generated using varying intervals, it may be impossible to receive the signal unless the receiver knows these changing intervals accurately. Through the use of this feature, the FTN transmission method can be applied to encrypted communication.

1 shows a structure of a modulation unit according to an embodiment.

The modulation unit 100 may generate an encrypted signal based on the FTN.

The modulation unit 100 includes a demultiplexer (DeMUX) 110, a plurality of FTN mappers 120, a plurality of Fast Fourier Transform (FFT) units 130, a plurality of truncation units, A multiplexer (MUX) 150, and a symbol interleaver 160. In one embodiment,

The number of FTN mapers 120 may be k . The number of the fast Fourier transform units 130 may be k . The plurality of cut portions 140 may be k pieces. In FIG. 1, as the k FTN mappers 120, the first FTN mapper 120-1 to the k-th FTN mapper 120- k are shown. Also, the k - th fast Fourier transform unit 130-1 to the k-th fast Fourier transform unit 130-k are shown as k fast Fourier transform units 130. [ It was also shown that the first cut portion 140-1 to the k cutout (140- k) as the k-cut 140. The

k may be an integer of 2 or more.

The function and operation of the demultiplexer 110, the plurality of FTN mappers 120, the plurality of fast Fourier transformers 130, the plurality of cutouts 140, the multiplexer 150 and the symbol interleaver 160 will be described below Will be described with reference to Fig.

2 is a flowchart of a modulation method according to an embodiment.

First, the input of the demultiplexer 110 may be a symbol sequence a .

In embodiments, the " symbol stream " may be considered a single-carrier sequence that is the input of an Orthogonal Frequency-Division Multiplexing (OFDM) communication device.

The input symbol sequence a can be expressed by Equation (1) below.

The length of the symbol row a may be x .

In step 210, the demultiplexer 110 may generate a plurality of segmented symbol sequences of the divided symbol sequence group by segmenting the input symbol sequence based on the first encryption information have.

First encryption information may be a first cryptographic code τ _ D.

The divided symbol sequence groups may be symbol sequences of the following equation (2).

The divided symbol column group may include k divided symbol columns.

First encryption code τ _ D may be an encryption code, such as the equation (3) below.

An m < th & gt; symbol stream a & lt; m & gt ; of the divided symbol sequence group can be expressed by Equation (4) below. m may be an integer of 1 or more and k or less.

In Equation (4), i ( m ) can be defined as Equation (5) and Equation (6) below.

As described above, the first encryption information may indicate a manner of dividing the input symbol sequence a .

First encryption code τ _ D may represent the lengths of the divided symbol stream of the split symbol sequence groups generated by dividing the symbol stream a. Here, the length of the symbol stream may be the number of symbols in the symbol stream.

First encryption code τ _ D may have a k-factor (element). The mth element τ _ D _m of the first encryption code τ _ D may indicate the length of the mth symbol stream a < m > of the divided symbol streams.

In one embodiment, each of the first encryption code elements of τ _ D may be a multiplier (power of 2) of Fig.

In one embodiment, the first element of each of the encryption code, τ _ D represents at least 4 of the multiplier 2, it may be a value less than or equal to the default value. For example, a first cryptographic code elements of τ _ D may be one of 4, 8, 16, 32 and 64.

First encryption code values of the elements of τ _ D may be limited based on the reasons below.

1) the divided symbol sequences a <1>, a <2 >, ..., a <k> is the FTN after the mapper 120, is input to the FFT units 130, FFT units 130 Due to the complexity of implementation of Fast Fourier Transform (FFT) of FFT, each size of the divided symbol streams needs to be limited to a multiplier of 2.

2) The receiving apparatus 300, which will be described later, uses Inverse Fast Fourier Transform (IFFT) to obtain the original symbols. As the size of each of the divided symbol streams is smaller, the FFT and the IFFT Can be reduced. The smaller the error, the more accurately the transmitted symbols can be demodulated.

In step 220, the FTN mappers 120 perform pre-pulse shaping on the divided symbol streams of the divided symbol stream group based on the first encryption information and the second encryption information To generate pre-pulse shaped symbol streams of a pre-pulse shaped symbol sequence group.

M second FTN mapper of the FTN mapper 120 is the first encryption information and the second divided on the basis of encrypted information symbol sequence a by performing a line pulse shaping for the <m> line-pulse shaped symbol sequence b <m &Gt; The divided symbol sequence a & lt; m > can be converted into a symbol sequence b & lt; m & gt; that is pre-pulse-formed by the m- th FTN mapper.

An FTN can be applied to a plurality of divided symbol streams through linear pulse shaping.

The filter coefficient of the linear pulse shaping may be a sampled value of a sinc function or a sampled value of a raised cosine function. Each FTN mapper 120 of the FTN mappers 120 may output the result of a cicular convolution operation on the input divided symbol stream and the filter coefficients as a pre-pulse shaped symbol stream.

The filter coefficients of the pre-pulse shaping of the FTN mappers 120 may be determined based on the FTN parameters.

The FTN parameter may include a sampling time adjustment variable ? Of the FTN.

For example, the linear modulation of the FTN mapers 120 may be expressed as: &lt; EMI ID = 7.0 &gt;

s _i can represent the i- th symbol. g ( t ) may represent an FTN mapper. τ may be a sampling time control variable. T may be the symbol transmission rate at the Nyquist rate. t can represent the time.

The length of the FTN mapper may be equal to the length of the divided symbol sequence, which is the symbol sequence input to the FTN mapper.

The FTN parameter or ? Of the FTN mapper 120 may be determined based on the first encryption information and / or the second encryption information.

The second encryption information may be encryption information used in a process of disconnection described later.

Second encryption information may be a second encryption code τ _ N. FTN parameters or τ may be determined based on a first encryption code and τ _ D / second encryption code τ _ N.

Second encryption code τ _ N may be an encryption code, such as the equation (8) below.

Second encryption code τ _ N may have a k of elements.

Claim for the second encryption code τ _ N, is described in more detail in step 240.

FTN mapper (120) of the m-th τ FTN mapper τ _m can be determined as shown in Equation 9 below.

Alternatively, τ _m may be an FTN parameter of the m th path.

Here, the m- th path may represent a process of processing the symbol sequence by the m- th FTN mapper, the m- th fast Fourier transform unit, and the m- th cut unit.

Τ in the m-th mapper FTN FTN the mapper 120 may be a value obtained by dividing the m-th element of the second encryption code to the m-th element of the first cryptographic code.

In step 230, the FFT units 130 apply FFT to the pre-pulse shaped symbol streams of the pre-pulse shaped symbol sequence group based on the first cryptographic information to generate a fast Fourier transformed symbol stream group The fast Fourier transformed symbol streams can be generated.

Based on the m-th element of the first cryptographic code, the m-th FFT unit of FFT units 130, line - a Fast Fourier transformed symbol sequence c <m> by performing the FFT on the pulse forming the symbol sequence b <m> Can be generated. The pre-pulse-formed symbol sequence b < m > can be transformed into a fast Fourier transformed symbol sequence c < m > by the m- th FFT unit.

The lengths of the FFTs performed by the FFT units 130 may be determined based on the first encryption code. The first encryption code may represent the lengths of the FFTs performed by the FFT units 130. [ The length of the FFT performed by the m- th FFT unit may be τ _ D _m .

Line-shaped pulses symbol sequence b <1>, b <2 >, ..., b <k> are each of length _{τ _ D 1, τ _ D} 2, ..., D _k can be τ _ have. The lengths of the fast Fourier transformed symbol streams c <1>, c <2>, ..., c < k > are pre-pulse shaped symbol streams b <1>, b <2> ,. ..., b & lt; k & gt ;, respectively.

Each of the fast Fourier transformed symbol streams c <1>, c <2>, ..., c < k > is composed of 1) a filter according to the filter coefficient used in the FTN mapper 130, and 2) Lt; RTI ID = 0.0 &gt; of &lt; / RTI &gt; some of the symbols. This shape may be the result of applying pulse shaping to generate FTN interference between the symbols, depending on the number of filters used in the FTN mappers 130. [ Also, the value of the symbol of some of the symbols may be attenuated by filtering.

In step 240, the cut-offs 140 may generate truncated symbol streams of the truncated symbol stream group by performing truncation on the fast Fourier transformed symbol streams of the fast Fourier transformed symbol stream group .

The m- th cut section of the cutouts 140 can generate a truncated symbol row d < m > by performing truncation on a fast Fourier transformed symbol stream c < m >. The fast Fourier transformed symbol sequence c < m > can be transformed into a symbol sequence d < m > truncated by the m- th cut.

The truncated symbol stream may be a symbol stream of the FTN signal. That is to say, the truncated symbol streams d <1>, d <2>, ..., d < k > may be symbol streams of the FTN signal.

The lengths of the truncated symbol streams may be determined based on the second encryption code. Alternatively, the second encryption code may represent the lengths of the truncated symbol streams. The length of the truncated symbol row d < m > may be τ _ N _m .

The attenuated symbols in the fast Fourier transformed symbol stream c & lt; m > through the truncation can be eliminated. Alternatively, a Fast Fourier Transform over the cutting length of the symbol sequence c <m> may be reduced to τ _ N _m.

Second encryption code τ _ D may represent the length of the symbol sequence of the FTN signal generated by the modulator. The symbol streams of the FTN signal may be truncated symbol streams d <1>, d <2>, ..., d < k >.

In step 250, the multiplexer 150 may generate a multiplexed symbol stream by performing multiplexing on the truncated symbol streams in the truncated symbol stream group.

The multiplexed symbol stream d can be defined as Equation (10) below.

The multiplexed symbol stream d may be a multiplexed symbol stream in the order of the truncated symbol streams d <1>, d <2>, ..., d < k >. Alternatively, the multiplexed symbol stream d may be a concatenation of truncated symbol streams d <1>, d <2>, ..., d < k >.

In step 260, the symbol interleaver 160 may generate an interleaved symbol stream by performing interleaving on the multiplexed symbol stream.

The symbol interleaver 160 may generate an interleaved symbol stream by mixing the multiplexed symbol streams in a predetermined order.

The modulation unit 100 may output an interleaved symbol stream. The interleaved symbol stream may be the output of the modulator 100.

The lengths of the multiplexed symbol streams d and the interleaved symbol streams may be the same.

The length L ( d ) of the multiplexed symbol stream d may be determined based on the FTN parameter ? _M.

The FTN parameter τ _m in the m- th path may be a ratio of a divided symbol sequence a < m > and a truncated symbol sequence d < m >. The divided symbol sequence a < m > may be an input symbol sequence of the m- th path. The truncated symbol row d < m > may be the output symbol sequence of the m- th path.

The length L ( d ) of the multiplexed symbol stream d can be defined as Equation (11) below.

L ( a ) may be the length of the symbol sequence a .

The average value τ _avr of the k FTN parameters can be defined as Equation (12) below.

는 심볼열 a 의 길이 및 제1 암호화 코드 τ _ D 에 의한 분리에 의해 생성된 분리된 심볼열 a < m >의 길이의 비율일 수 있다.

는 아래의 수학식 13과 같이 정의될 수 있다.

It may be a ratio of the symbol sequence and a length of the first encryption code, τ _ sliced symbols generated by the separation by column D, a length of <m> of.

Can be defined as Equation (13) below.

If the values of the elements of the first encryption code are all the same, the average value τ _avr of the k FTN parameters can be defined as Equation (14) below.

The description of the length of the multiplexed symbol stream d described above can also be applied to the length of the interleaved symbol stream and the length of the symbol stream output from the modulation unit 100. [

As described above, in the modulation process, at least one of k divided symbol streams, k pre-pulse formed symbol streams, k fast Fourier transformed symbol streams, and k truncated symbol streams is May be generated based on the encryption information.

The encryption information may include first encryption information and second encryption information. Alternatively, the encryption information may include a first encryption code and a second encryption code.

In the above-described process, the FTN interference based on the first cipher information and the second cipher information can be variably applied to each of the divided symbol streams. Only when both the first encryption information and the second encryption information are known to the receiving apparatus, the receiving apparatus can receive the transmitted symbols using the first encryption information and the second encryption information as parameters for demodulating the symbols. That is to say, the method of generating the encrypted signal described in the embodiment can generate an encrypted signal based on the FTN using two pieces of encryption information.

3 shows a structure of a demodulation unit according to an embodiment.

The demodulator 300 may decrypt the encrypted signal based on the FTN.

The demodulator 300 includes a symbol deinterleaver 310, a demultiplexer 320, a plurality of zero padding units 330, a plurality of Inverse Fast Fourier Transform (IFFT) units 340, A plurality of FTN interference cancellers 350 and a multiplexer 360.

The plurality of zero padding units 330 may be k . The number of the inverse fast Fourier transform units 340 may be k . The number of FTN interference cancellers 350 may be k . In FIG. 1, as the k zero padding units 330, the first zero padding unit 330-1 through the k - th zero padding unit 330- k are shown. In addition, k of the inverse fast Fourier transform unit, the first gosuk Fourier (340-1) to the k-th inverse fast Fourier transform unit (340- k) a conversion units 340 is shown. It was also shown that the first interference rejection FTN the (350-1) to the k-th interference rejection FTN the (350- k) as k FTN of interference cancellation units 350.

k may be an integer of 2 or more.

The functions of the symbol deinterleaver 310, the demultiplexer 320, the plurality of zero padding units 330, the plurality of inverse fast Fourier transform units 340, the plurality of FTN interference cancellers 350 and the multiplexer 360, The operation will be described below with reference to Fig.

4 is a flowchart of a demodulation method according to an embodiment.

The first encryption information and the second encryption information used in the modulation unit 100 may be notified to the demodulation unit 300. [ For example, the transmitting apparatus including the modulating unit 100 can provide the first encrypting information and the second encrypting information to the receiving apparatus including the demodulating unit 200. [

First, a symbol sequence may be input to the demodulation unit 300. The symbol sequence may be a preprocessed symbol sequence. The preprocessing may include synchronization and channel estimation.

In step 410, the symbol deinterleaver 310 may deinterleave the input symbol stream to generate a deinterleaved symbol stream.

The symbol deinterleaver 310 may generate a deinterleaved symbol stream by mixing the input symbol streams in a predetermined order.

The deinterleaving by the symbol deinterleaver 310 may be the inverse of the interleaving of the symbol interleaver 160 of the modulating unit 100. The predefined order in which the symbol deinterleaver 310 mixes the input symbol streams may be to return the interleaved symbol streams back to the order before interleaving by the symbol interleaver 160.

은 변조부(100)의 FTN 심볼열 d 에 대응할 수 있다. 예를 들면, 심볼열

는 변조부(100)의 FTN 심볼열 d 이 수신된 추정 심볼열일 수 있다.Deinterleaved symbol columns

May correspond to the FTN symbol row d of the modulation unit 100. [ For example,

May be an estimated symbol sequence from which the FTN symbol sequence d of the modulation unit 100 is received.

를 분할(segment)함으로써 분할된(segmented) 심볼열 그룹의 분할된 심볼열들을 생성할 수 있다.In step 420, the demultiplexer 320 demultiplexes the deinterleaved symbol stream &lt; RTI ID = 0.0 &gt;

To thereby generate segmented symbol streams of a segmented symbol stream group.

Step 410 may be optional. If step 410 is not performed, the input of the demultiplexer 320 may be an input symbol stream, and the demultiplexer 320 may generate the divided symbol streams by dividing the input symbol stream.

Second encryption information may be a second encryption code τ _ N.

The divided symbol string group may include symbol strings of Equation (15) below.

The divided symbol column group may include k divided symbol columns.

Second encryption code τ _ N may be an encryption code, such as Equation 16 below.

을 분할하는 방식을 나타낼 수 있다.The second encryption information includes deinterleaved symbol stream

Can be represented by a method of dividing the image.

을 분할함으로써 생성된 분할된 심볼열 그룹의 분할된 심볼열들의 길이들을 나타낼 수 있다. 여기에서, 심볼열의 길이는 심볼열의 심볼들의 개수일 수 있다.Second encryption code τ _ N is deinterleave the symbol sequence

Lt; RTI ID = 0.0 &gt; a &lt; / RTI &gt; divided symbol sequence group generated by dividing the divided symbol sequences. Here, the length of the symbol stream may be the number of symbols in the symbol stream.

< m >의 길이를 나타낼 수 있다.Second encryption code τ _ N may have a k-factor (element). Second encryption code τ _ N of the m-th element τ _ N _m m-th column is the symbol of the split symbol streams

lt; m &gt;

< m >은 m 번째 경로로 입력될 수 있다. The mth divided symbol stream

< m > can be input to the m- th path.

Here, the m- th path may represent a process of processing the symbol sequence by the m- th zero padding unit, the m- th inverse fast Fourier transform unit, and the m- th FTN interference cancellation unit.

In step 430, the zero padding units 330 insert the at least one " 0 " into each of the divided symbol sequences of the divided symbol sequence group based on the first encryption information, It is possible to generate adjusted symbol streams.

< m >에 적어도 하나의 "0"을 삽입함으로써 길이 조절된 심볼열

< m >을 생성할 수 있다. 분할된 심볼열

< m >은 m 번째 제로 패딩부에 의해 길이 조절된 심볼열

< m >로 변환될 수 있다.The m < th > zero padding portion of the zero padding portions 330 includes a symbol stream &lt;

By inserting at least one " 0 &quot; in &lt; m & gt ;, a length-

&lt; m &gt;. Partitioned symbol column

&lt; m & gt ; is a symbol string length-adjusted by the m &lt; th & gt ;

lt; m &gt;.

The length-adjusted symbol sequence group may include symbol sequences of Equation (17) below.

The zero padding by the zero padding portions 330 may be to insert a " 0 " at a specified symbol position in the symbol stream. The specified symbol position may be the position of the symbol removed by cutting of the cuts 140 of the modulation section 100. [

The zero padding portions 330 may determine the number of at least one " 0 " inserted in each of the divided symbol streams based on the first encryption information.

< m >의 길이는 제1 암호화 코드 τ _ D 의 m 번째 요소 τ _ D _m 일 수 있다. m 번째 제로 패딩부는 길이 조절된 심볼열

< m >의 길이가 제1 암호화 코드 τ _ D 의 m 번째 요소 τ _ D _m 가 되도록 적어도 하나의 "0"을 분할된 심볼열

< m >에 삽입할 수 있다. 또는, 분할된 심볼열

< m >에 삽입되는 적어도 하나의 "0'의 개수는 제1 암호화 코드 τ _ D 의 m 번째 요소 τ _ D _m 및 분할된 심볼열

< m >의 길이의 차(difference)일 수 있다.Length-controlled symbol columns

The length of < m > may be the m- th element τ _ D _m of the first encryption code τ _ D. The m < th & gt; zero padding portion includes a length-

<M> a length of the first encryption code, τ _ _ τ D of the m-th element is D _m to a symbol column dividing the at least one "0" of the

can be inserted in < m >. Alternatively,

The number of the at least one "0" to be inserted into the <m> is a first encryption code _ τ D of the m-th element τ _ D _m and split the symbol stream

may be the difference of the length of &lt; m &gt;.

In step 440, the IFFT units 340 apply an IFFT to the length-adjusted symbol streams of the length-adjusted symbol stream group based on the first encryption information, thereby generating a reverse fast Fourier transformed symbol stream group Thereby generating Fourier transformed symbol streams.

< m >에 대한 IFFT를 수행함으로써 역 고속 퓨리어 변환된 심볼열

< m >을 생성할 수 있다. 길이 조절된 심볼열

< m >은 m 번째 IFFT부에 의해 역 고속 퓨리어 변환된 심볼열

< m >로 변환될 수 있다.The m < th & gt; FFT unit of the IFFT units 340 generates a length-adjusted symbol stream

< m & gt ; by performing IFFT on the inverse fast Fourier transformed symbol stream

< m &gt;. Length-controlled symbol columns

<M> is the symbol an inverse fast Fourier transform by IFFT section m-th column

lt; m &gt;.

The inverse fast Fourier transformed symbol sequence group may include symbol sequences of the following Equation (18).

The IFFT of step 440 may be the inverse of the FFT of step 230 described above with reference to FIG.

The first encryption code may represent the length of the IFFT. The length of the IFFT performed by the m- th IFFT unit may be τ _ D _m .

<1>,

<2>,...,

< k >의 길이들은 각각 τ _ D ₁ , τ _ D ₂ , ..., τ _ D _k 일 수 있다. 역 고속 퓨리어 변환된 심볼열들

<1>,

<2>,...,

< k >의 길이들은 길이 조절된 심볼열들

<1>,

<2>,...,

< k >의 길이들과 각각 동일할 수 있다.As described above, the length-adjusted symbol streams

< 1 >,

&Lt; 2 & gt ;, ...,

The lengths of < k > may be τ _ D ₁ , τ _ D ₂ , ..., τ _ D _k , respectively. The inverse fast Fourier transformed symbol streams

< 1 >,

&Lt; 2 & gt ;, ...,

The lengths < k & gt; are the length-adjusted symbol sequences

< 1 >,

&Lt; 2 & gt ;, ...,

< k & gt ;, respectively.

<1>,

<2>,...,

< k >은 변조부(100)의 분할된 심볼열들 a <1>, a <2>,..., a < k >에 FTN이 적용됨에 따라서 FTN 간섭을 갖는 심볼열들에 대응할 수 있다. The inverse fast Fourier transformed symbol streams

< 1 >,

&Lt; 2 & gt ;, ...,

<K> can correspond to the divided symbol sequences a <1>, a <2 >, ..., symbol sequence having the FTN interference according to the FTN is applied to a <k> of the modulator 100 .

The divided symbol sequences a <1>, a <2 >, ..., a <k> is generated as a symbol sequence input to a modulator 100, a first encryption code τ _ based on the division D Lt; / RTI &gt;

In step 450, the FTN interference cancellers 350 remove the FTN interference from each of the inverse fast Fourier transformed symbol sequences of the inverse fast Fourier transformed symbol sequence group based on the FTN parameter, It is possible to generate symbol sequences from which the FTN interference of the symbol row group is removed.

< m >로부터 FTN 간섭을 제거함으로써 FTN 간섭이 제거된 심볼열

< m >을 생성할 수 있다. 역 고속 퓨리어 변환된 심볼열

< m >은 m 번째 IFFT부에 의해 FTN 간섭이 제거된 심볼열

< m >로 변환될 수 있다.The m < th & gt ; FTN interference canceller of the FTN interference cancellers 350 generates an inverse fast Fourier transformed symbol sequence <

&lt; RTI ID = 0.0 &gt; FTN &lt; / RTI & gt ;

&lt; m &gt;. The inverse fast Fourier transformed symbol sequence

&lt; m & gt ; is a symbol sequence in which FTN interference is removed by the m &lt; th & gt ;

lt; m &gt;.

The FTN interference removed by the m &lt; th & gt; FTN interference cancellation may be a cyclic convolution of the first and second filter coefficients. The first filter coefficient may be the filter coefficient used in the m &lt; th & gt; FTN mapper. That is, the first filter coefficient may be a filter coefficient of the FTN mapper used in modulation of the input symbol stream. The second filter coefficient may be a filter coefficient obtained by an IFFT transform of a rectangular window of the cut corresponding to a post-pulse shaping process. That is to say, the second filter coefficient may be a filter coefficient obtained by IFFT transform of the rectangular window of the cut used in the modulation of the input symbol stream.

< m >로부터 FTN 간섭을 제거함으로써 FTN 간섭이 제거된 심볼열

< m >을 생성할 수 있다. The m < th & gt; FTN interference canceller uses the cyclic convolution of the first filter coefficient and the second filter coefficient to perform an inverse fast Fourier transform

< RTI ID = 0.0 > FTN &lt; / RTI & gt ;

&lt; m &gt;.

In step 460, the multiplexer 360 may generate a multiplexed symbol stream by performing multiplexing on FTN interference canceled symbol streams of the symbol train group from which the FTN interference has been removed.

은 추정된 심볼열일 수 있다.Multiplexed symbol columns

May be an estimated symbol sequence.

은 FTN 간섭이 제거된 심볼열들이 순서대로 멀티플렉스된 심볼열일 수 있다. 또는, 멀티플렉싱된 심볼열

은 FTN 간섭이 제거된 심볼열들의 연쇄(concatenation)일 수 있다.Multiplexed symbol columns

May be a symbol sequence in which FTN interference-canceled symbol sequences are sequentially multiplexed. Alternatively, a multiplexed symbol stream

May be a concatenation of symbol streams with FTN interference removed.

As described above, at least one of the divided symbol streams, the length-adjusted symbol streams, the inverse fast Fourier transformed symbol streams, and the FTN interference-canceled symbol streams may be generated based on the encryption information.

5 and 6 show an OFDM transmitting apparatus and an OFDM receiving apparatus of an OFDM communication system using a method of modulating an encrypted signal based on FTN according to an embodiment, respectively.

5 is a structural diagram of an OFDM transmitting apparatus using a method of modulating an encrypted signal based on FTN according to an embodiment.

An Orthogonal Frequency Division Multiplexing (OFDM) transmission apparatus 500 may include a modulation unit 100 and an OFDM transmission unit 510.

The OFDM transmitter 510 may include a subcarrier mapping unit 511, a pilot insertion unit 512, an IFFT unit 513, a cyclic prefix (CP) insertion unit 514, and a transmission unit 515.

The functions and operations of the modulation unit 100, the subcarrier mapping unit 511, the pilot insertion unit 512, the IFFT unit 513, the CP insertion unit 514, and the transmission unit 515 will be described below with reference to FIG. do.

6 is a structural diagram of an OFDM receiving apparatus using a method of demodulating an encrypted signal based on FTN according to an embodiment.

The OFDM receiver 600 may include an OFDM receiver 610 and a demodulator 300.

The OFDM receiving unit 610 includes a receiving unit 611, a CP removing unit 612, an FFT unit 613, a synchronization and channel estimation and compensation unit 614, and a sub-carrier demapping unit 615 ).

The functions and operations of the demodulation unit 300, the reception unit 611, the CP removal unit 612, the FFT unit 613, the synchronization and channel estimation and compensation unit 614 and the subcarrier demapping unit 615 will be described below Will be described with reference to Fig.

7 is a flow diagram of a method for transmitting an encrypted signal based on an FTN according to one embodiment.

In step 710, the modulation unit 100 of the transmitting apparatus 500 may generate an encrypted signal based on the FTN.

In step 720, the subcarrier mapping unit 511 may map the encrypted signal to the corresponding subcarrier.

In step 730, the pilot inserting unit 512 may insert a pilot signal into the output of the subcarrier mapping unit 511. [

In step 740, the IFFT unit 513 may perform an IFFT on the output of the pilot inserter 512. [

In step 750, the CP insertion unit 514 may insert a CP into the output of the IFFT unit 513. [

In step 760, the transmitting unit 515 may transmit the output of the CP inserting unit 514 to the receiving apparatus 600 through the channel.

8 is a flow diagram of a method of receiving an encrypted signal based on an FTN according to one embodiment.

In step 810, the receiving unit 611 can receive the signal transmitted from the transmitting apparatus 500 through the channel.

At step 820, CP removal 612 may remove the CP from the received signal.

In step 830, the FFT unit 613 may perform an FFT on the output of the CP removal unit 612.

In step 840, the synchronization and channel estimation and compensation unit 614 may perform synchronization and channel estimation and compensation on the output of the FFT unit 613.

In step 850, the subcarrier demapping unit 615 may perform subcarrier demapping on the outputs of the synchronization and channel estimation and compensation unit 614.

In step 860, the demodulator 300 may perform demodulation on the output of the subcarrier demodulator 615.

When the FTN signal communication method by the modulation unit 100 and the demodulation unit 200 proposed in the transmission apparatus 700 and the reception apparatus 800 of the OFDM communication system are used, Interference may not have an effect on the pilot. Since the interference generated in the FTN signal generation process does not affect the pilot, the synchronization and channel estimation and compensation methods used in the transmission and reception processes of the signal in the existing OFDM communication system are used as they are, May be transmitted and received.

9 illustrates an electronic device implementing a transmitting device according to one embodiment.

The modulation unit 100 or the transmission device 500 may be implemented as the electronic device 900 shown in Fig. The electronic device 900 may be a general purpose computer system that operates as the modulation unit 100 or the transmission device 500.

9, the electronic device 900 may include at least some of a processing unit 910, a communication unit 920, a memory 930, a storage 940, and a bus 990. Components of the electronic device 900, such as the processing unit 910, the communication unit 920, the memory 930, and the storage 940, may communicate with each other via the bus 990.

The processing unit 910 may be a semiconductor device that executes the processing instructions stored in the memory 930 or the storage 940. For example, the processing unit 910 may be at least one hardware processor.

The processing unit 910 can process the job required for the operation of the electronic device 900. [ The processing unit 910 may execute the code of the operation or step of the processing unit 910 described in the embodiments.

The processing unit 910 may perform generation, storage, and output of information to be described in the embodiment to be described later, and may perform an operation of a step performed in the other electronic device 900.

The communication unit 920 can be connected to the network 999. May receive data or information required for operation of electronic device 900 and may transmit data or information required for operation of electronic device 900. [ The communication unit 920 can transmit data to another device via the network 999 and can receive data from another device. For example, the communication unit 920 may be a network chip or a port.

Memory 930 and storage 940 may be various types of volatile or non-volatile storage media. For example, memory 930 may include at least one of ROM (R) 931 and RAM (RAM) 932. The storage 940 may include internal storage media such as RAM, flash memory and hard disk, and may include removable storage media such as memory cards and the like.

The function or operation of the electronic device 900 may be performed as the processing unit 910 executes at least one program module. The memory 930 and / or the storage 940 may store at least one program module. At least one program module may be configured to be executed by the processing unit 910. [

The demultiplexer 110, the plurality of FTN mappers 120, the plurality of fast Fourier transformers 130, the plurality of cutouts 140, the multiplexer 150, and the symbol interleaver 160 May be at least one program module.

At least a part of the modulation unit 100, the subcarrier mapping unit 511, the pilot insertion unit 512, the IFFT unit 513, the CP insertion unit 514, and the transmission unit 515 of the above- Lt; / RTI &gt;

The program modules may be included in the electronic device 900 in the form of an operating system, an application module, a library, and other program modules, and may be physically stored on various well-known storage devices. Also, at least some of these program modules may be stored in a remote storage device capable of communicating with the electronic device 900. These program modules may be implemented as routines, subroutines, programs, and / or programs for performing specific operations or tasks according to the embodiments or for executing specific abstract data types. and may include, but is not limited to, an object, a component, and a data structure.

The electronic device 900 may further include a user interface (UI) input device 950 and a UI output device 960. The UI input device 950 may receive the user's input required for operation of the electronic device 900. [ The UI output device 960 can output information or data according to the operation of the electronic device 900.

The electronic device 900 may further include a transmitting unit 970. Transmitter 970 may be a transmit antenna. The transmitting unit 970 may correspond to the transmitting unit 515 described above with reference to FIG.

10 illustrates an electronic device implementing a receiving device according to one embodiment.

The demodulation unit 300 or the reception device 600 may be implemented as the electronic device 1000 shown in FIG. The electronic device 1000 may be a general purpose computer system that operates as a demodulator 300 or a receiving device 600.

10, the electronic device 1000 may include at least some of the processing unit 1010, the communication unit 1020, the memory 1030, the storage 1040, and the bus 1090. [ Components of the electronic device 1000 such as the processing unit 1010, the communication unit 1020, the memory 1030 and the storage 1040 can communicate with each other via the bus 1090. [

The processing unit 1010 may be a semiconductor device that executes the processing instructions stored in the memory 1030 or the storage 1040. [ For example, the processing unit 1010 may be at least one hardware processor.

The processing unit 1010 can process a job required for the operation of the electronic device 1000. [ The processing unit 1010 may execute the code of the operation or step of the processing unit 1010 described in the embodiments.

The processing unit 1010 may perform generation, storage, and output of information to be described in the following embodiments, and may perform operations of steps performed in the other electronic device 1000.

The communication unit 1020 can be connected to the network 1099. May receive data or information required for operation of electronic device 1000 and may transmit data or information required for operation of electronic device 1000. [ The communication unit 1020 can transmit data to another device via the network 1099 and can receive data from another device. For example, the communication unit 1020 may be a network chip or a port.

Memory 1030 and storage 1040 can be various types of volatile or non-volatile storage media. For example, the memory 1030 may include at least one of a ROM (ROM) 1031 and a RAM (RAM) The storage 1040 may include internal storage media such as RAM, flash memory and a hard disk, and may include removable storage media such as memory cards and the like.

The function or operation of the electronic device 1000 may be performed as the processing unit 1010 executes at least one program module. Memory 1030 and / or storage 1040 may store at least one program module. The at least one program module may be configured to be executed by the processing unit 1010. [

A symbol deinterleaver 310, a demultiplexer 320, a plurality of zero padding units 330, a plurality of inverse fast Fourier transform units 340, a plurality of FTN interference cancellers 350, And at least some of the multiplexers 360 may be at least one program module.

The demodulating unit 300, the receiving unit 611, the CP removing unit 612, the FFT unit 613, the synchronization and channel estimating and compensating unit 614, and the subcarrier demapping unit 615 of the receiving apparatus 600 described above, At least some of which may be at least one program module.

The program modules may be included in the electronic device 1000 in the form of an operating system, an application module, a library, and other program modules, and may be physically stored on various known memory devices. Also, at least some of these program modules may be stored in a remote storage device capable of communicating with electronic device 1000. These program modules may be implemented as routines, subroutines, programs, and / or programs for performing specific operations or tasks according to the embodiments or for executing specific abstract data types. and may include, but is not limited to, an object, a component, and a data structure.

The electronic device 1000 may further include a user interface (UI) input device 1050 and a UI output device 1060. The UI input device 1050 can receive a user's input required for operation of the electronic device 1000. The UI output device 1060 can output information or data according to the operation of the electronic device 1000.

The electronic device 1000 may further include a receiving unit 1070. The receiving unit 1070 may be at least one receiving antenna. The receiving unit 1070 may correspond to the receiving unit 611 described above with reference to FIG.

The apparatus described above may be implemented as a hardware component, a software component, and / or a combination of hardware components and software components. For example, the apparatus and components described in the embodiments may be implemented within a computer system, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA) A programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For ease of understanding, the processing apparatus may be described as being used singly, but those skilled in the art will recognize that the processing apparatus may have a plurality of processing elements and / As shown in FIG. For example, the processing unit may comprise a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as a parallel processor.

The software may include a computer program, code, instructions, or a combination of one or more of the foregoing, and may be configured to configure the processing device to operate as desired or to process it collectively or collectively Device can be commanded. The software and / or data may be in the form of any type of machine, component, physical device, virtual equipment, computer storage media, or device , Or may be permanently or temporarily embodied in a transmitted signal wave. The software may be distributed over a networked computer system and stored or executed in a distributed manner. The software and data may be stored on one or more computer readable recording media.

The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

500: MIMO-FTN communication system
510: Transmitting device
511: Signal generators
520: Receiving device
512: signal modulation parts
513: Transmission filters
514: Multiple transmit antennas
520: Receiving device
521: Multiple receive antennas
522: Receive filters
523: Samplers
524: MIMO signal processor
525: FTN interference cancellation and demodulation units
600: a MIMO signal processor

Claims (20)

A method for modulating an input symbol stream using encryption information,
Generating divided symbol streams by dividing the input symbol stream;
Generating pre-pulse shaped symbol streams by performing linear pulse shaping on the divided symbol streams;
Generating fast Fourier transformed symbol sequences by applying Fast Fourier Transform (FFT) on the pre-pulse-formed symbol sequences;
Generating truncated symbol streams by performing truncation on the fast Fourier transformed symbol streams; And
Generating a multiplexed symbol stream by performing multiplexing on the truncated symbol streams;
Wherein at least one of the divided symbol streams, the pre-pulse-formed symbol streams, the FFT-transformed symbol streams, and the truncated symbol streams are generated based on encryption information, A method of modulating heat. The method according to claim 1,
Wherein the encryption information includes first encryption information,
Wherein the first encryption information indicates a scheme of dividing the input symbol stream. The method according to claim 1,
Wherein the encryption information includes a first encryption code,
Wherein the first encryption code represents the lengths of the divided symbol streams. The method according to claim 1,
Wherein each of the elements of the first encryption code is a power of two. The method according to claim 1,
Wherein the encryption information includes a first encryption code and a second encryption code,
The linear pulse shaping is performed by Faster-Than-Nyquist (FTN) mappers,
Wherein the FTN parameters of the FTN mappers are determined based on a first encryption code and a second encryption code. 6. The method of claim 5,
Wherein the FTN parameter comprises a sampling time control variable of the FTN,
The sampling time control parameter of the m-th FTN mapper among the FTN mappers is a value obtained by dividing the m-th element of the second cryptographic code by the m-th element of the first cryptographic code,
and m is an integer of 1 or more. The method according to claim 6,
Wherein the sampling time control parameter of the m-th FTN mapper is a ratio of m-th segmented symbol streams among the mapped symbol streams and m-th segmented symbol streams among the segmented symbol streams. The method according to claim 1,
Wherein the encryption information includes a first encryption code,
Wherein the first encryption code represents a length of the FFT. The method according to claim 1,
Wherein the encryption information includes a second encryption code,
And wherein the second encryption code represents the lengths of the truncated symbol streams. The method according to claim 1,
Generating interleaved symbol streams by performing interleaving on the multiplexed symbol streams;
&Lt; / RTI &gt; An apparatus for modulating an input symbol stream using encryption information,
A demultiplexer for generating the divided symbol streams by dividing the input symbol stream;
FTN mappers for generating pre-pulse shaped symbol streams by performing linear pulse shaping on the divided symbol streams;
FFT units for generating the fast Fourier transformed symbol streams by applying Fast Fourier Transform (FFT) to the pre-pulse-formed symbol streams;
Cutoffs for generating truncated symbol streams by performing truncation on the fast Fourier transformed symbol streams; And
A multiplexer for generating a multiplexed symbol stream by performing multiplexing on the truncated symbol streams;
Lt; / RTI &gt;
Wherein at least one of the divided symbol streams, the pre-pulse-formed symbol streams, the FFT-transformed symbol streams, and the truncated symbol streams are generated based on encryption information. A method for demodulating an input symbol stream using encryption information,
Generating divided symbol streams by dividing the input symbol stream;
Generating length-adjusted symbol streams by inserting at least one " 0 " in each of the divided symbol streams;
Generating inverse fast Fourier transformed symbol sequences by applying Inverse Fast Fourier Transform (IFFT) on the length-adjusted symbol streams;
Generating FTN interference canceled symbol sequences by removing FTN interference in each of the inverse fast Fourier transformed symbol sequences; And
Generating a multiplexed symbol stream by performing multiplexing on FTN interference canceled symbol streams;
Lt; / RTI &gt;
Wherein at least one of the divided symbol streams, the length-adjusted symbol streams, the inverse fast Fourier transformed symbol streams, and the FTN interference canceled symbol streams are generated based on the encryption information, How to demodulate. 13. The method of claim 12,
Generating a deinterleaved symbol stream by performing deinterleaving on the preprocessed symbol stream;
Further comprising:
Wherein the deinterleaved symbol stream is the input symbol stream. 13. The method of claim 12,
Wherein the encryption information includes second encryption information,
And the second encryption information indicates a method of dividing the input symbol stream. 13. The method of claim 12,
Wherein the encryption information includes a second encryption code,
And wherein the second encryption code represents the lengths of the divided symbol streams. 13. The method of claim 12,
Wherein the encryption information includes first encryption information,
Wherein the first encryption information determines the number of at least one " 0 " s inserted in each of the partitioned symbol streams. 13. The method of claim 12,
Wherein the encryption information includes a first encryption code,
Wherein a number of at least one " 0 " inserted in an m-th divided symbol stream among the divided symbol streams is a difference between lengths of an m-th element and an m-th divided symbol stream of the first encryption code Way. 13. The method of claim 12,
Wherein the encryption information includes a first encryption code,
Wherein the first encryption code indicates a length of the IFFT. 13. The method of claim 12,
Wherein each of the elements of the first encryption code is a power of two. 13. The method of claim 12,
Wherein the FTN interference is a cyclic convolution of a first filter coefficient and a second filter coefficient,
Wherein the first filter coefficient is a filter coefficient of an FTN mapper used in modulation of the input symbol stream,
Wherein the second filter coefficient is a filter coefficient obtained by an IFFT transform of a rectangular window of the cut used in the modulation of the input symbol stream.

Images