KR102139720B1 - DFT-s-OFDM TRANSMISSION APPARATUS AND METHOD, AND DFT-s-OFDM RECEPTION APPARATUS AND METHOD FOR SPECTRAL EFFICIENCY IMPROVEMENT IN WIRELESS COMMUNICATION SYSTEM - Google Patents

Abstract

로 표현되고, 여기서, i 및 j는 매트릭스의 행 및 열의 인덱스를 의미하며, 퓨리에 변환 함수의 분자 상의 인덱스 i와 관련된 컴포넌트에 (L-1)/2의 항을 포함함) 및 상기 프리코딩된 L 개의 심볼벡터들을 OFDM 신호로 변환하는 OFDM 변조기를 포함한다.One aspect of the present invention discloses a DFT-s-OFDM transmitter in a wireless communication system. The transmitter is a DFT precoder that receives M BPSK symbol vectors and precodes using a pruned DFT matrix to use subcarriers of L-L is a natural number less than M (here , The pruned DFT matrix

Where i and j are the indices of the rows and columns of the matrix, containing the term of (L-1)/2 in the component related to the index i on the numerator of the Fourier transform function) and the precoded And an OFDM modulator for converting L symbol vectors into OFDM signals.

Description

DFT-s-OFDM transmitter and transmission method for improving frequency efficiency in wireless communication system, and receiver and reception method IN WIRELESS COMMUNICATION SYSTEM}

The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for efficiently transmitting and receiving signals in a wireless communication system.

In 4G mobile communication, DFT-s-OFDM (DFT spread OFDM) technology, which is a kind of localized single-carrier frequency domain multiple access (SC-FDMA), is used to lower the peak-to-average-power ratio (PAPR) in the uplink. To perform wireless communication.

In addition, in order to solve the large problem of PAPR in the uplink of 5G mobile communication, it is intended to lower the PAPR by using pi/2-BPSK symbols together with the conventional DFT-s-OFDM.

However, in the case of the BPSK symbol, the frequency efficiency is reduced by 2 times compared to the QPSK symbol. That is, PAPR and frequency efficiency have a trade-off relationship with each other. In the case of the pi/2-BPSK DFT-s-OFDM system considered in 5G mobile communication, these parts are not optimized, and therefore the PAPR gain In comparison, frequency efficiency is wasted. Therefore, optimization is needed to maximize the frequency efficiency and the trade-off of PAPR.

Recently, a zero tail (ZT) DFT-s-OFDM has been proposed that allows an overhead such as a cyclic prefix (CP) to be flexibly applied to a signal. This ZT technique is a method of transmitting zeros instead of symbols at the front and back of a transmission symbol vector to be transmitted instead of a cyclic prefix. When transmitting in this way, it acts as a guard band on the time axis of DFT-s-OFDM, reducing IBI (Inter-Block Interference), making it robust to multipath channels, and reducing out-of-band radiation on the frequency axis. . However, this method has a problem in that frequency efficiency is reduced because 0 is sent instead of a symbol. Therefore, a method for improving the frequency efficiency is required.

An object according to an aspect of the present invention for solving the above-mentioned problem is to complement a pi/2-BPSK DFT-s-OFDM system considered in 5G, in a wireless communication system capable of increasing frequency efficiency while maintaining PAPR gain. DFT-s-OFDM transmitter and receiver.

In addition, an object according to another aspect of the present invention is to provide a DFT-s-OFDM system that can intuitively adjust the trade-off relationship between PAPR and frequency efficiency.

In addition, the object according to another aspect of the present invention is a new ZT (zero tail) DFT-s-OFDM that is robust to a multi-path system and has low out-of-band emission without loss of frequency efficiency and cyclic prefix using the above method. It is to provide a system.

로 표현되고, 여기서, i 및 j는 매트릭스의 행 및 열의 인덱스를 의미하며, 퓨리에 변환 함수의 분자 상의 인덱스 i와 관련된 컴포넌트에 (L-1)/2의 항을 포함함) 및 상기 프리코딩된 L 개의 심볼벡터들을 OFDM 신호로 변환하는 OFDM 변조기를 포함할 수 있다.A DFT-s-OFDM transmitter in a wireless communication system according to an aspect of the present invention for achieving the above object receives M BPSK symbol vectors and uses subcarriers of L-L is a natural number less than M- In order to do this, a DFT precoder that precodes using a pruned DFT matrix (where the pruned DFT matrix is

Where i and j are the indices of the rows and columns of the matrix, containing the term of (L-1)/2 in the component related to the index i on the numerator of the Fourier transform function) and the precoded And an OFDM modulator for converting L symbol vectors into OFDM signals.

로 산출될 수 있다.The pruned DFT matrix is

Can be calculated as

)(diagonal matrix)을 곱해주는 스펙트럼 쉐이퍼(spectrum shaper)를 더 포함할 수 있다.The transmitter diagonally matrixes the L symbol vectors of the precoding (

) (diagonal matrix) may further include a spectrum shaper (spectrum shaper).

The diagonal matrix may be a matrix of L coefficients including s ₀ to s _L-1 as LX 1 vectors.

In order to make the power spectral density symmetric, the coefficients of the diagonal matrix can be set symmetrically.

The coefficients of the diagonal matrix may satisfy the following condition of the first equation.

The coefficients of the diagonal matrix may satisfy the following condition of the second equation.

The transmitter may further include a zero padding symbol provider that provides zero padded symbols of (M _O -M)-M _O is a natural number greater than M to the DFT precoder to use M subcarriers. have.

The transmitter may further include a cyclic prefix inserter to insert a cyclic prefix (CP) into the OFDM signal.

의 역행렬로 표현되고, 여기서, i 및 j는 매트릭스의 행 및 열의 인덱스를 의미하며, 퓨리에 변환 함수의 분자 상의 인덱스 i와 관련된 컴포넌트에 (L-1)/2의 항을 포함할 수 있다.DFT-s-OFDM receiver in a wireless communication system according to another aspect of the present invention for achieving the above object, a cyclic prefix remover for receiving a received signal to remove a cyclic prefix (CP: Cyclic Prefix), the cyclic prefix N-point DFT operator that performs N DFT operations on the N symbol vectors from which N is removed, and L samples-N is a natural number less than N-by removing frequency samples for N symbol vectors that have undergone DFT computation. IDFT using a pruned IDFT matrix to generate a symbol vector of an equalizer outputting a symbol vector and L symbol vectors and M-M is a natural number greater than L. An IDFT operator to perform the operation, wherein the pruned IDFT matrix is

Represented by the inverse matrix of, where i and j mean the index of the row and column of the matrix, and may include the term of (L-1)/2 in the component related to the index i on the numerator of the Fourier transform function.

)(diagonal matrix)을 곱해줄 수 있다.The receiver further includes a spectral shaper between the equalizer and the IDFT operator, wherein the spectral shaper is diagonal to the L symbol vectors (

)(diagonal matrix).

로 표현되고, 여기서, i 및 j는 매트릭스의 행 및 열의 인덱스를 의미하며, 퓨리에 변환 함수의 분자 상의 인덱스 i와 관련된 컴포넌트에 (L-1)/2의 항을 포함함) 및 상기 프리코딩된 L 개의 심볼벡터들을 OFDM 신호로 변환하는 단계를 포함할 수 있다.A method of transmitting a DFT-s-OFDM transmitter in a wireless communication system according to another aspect of the present invention for achieving the above object, receives M BPSK symbol vectors, L-L is a natural number less than M- Precoding using a pruned DFT matrix to use a subcarrier of (where the pruned DFT matrix is

Where i and j are the indices of the rows and columns of the matrix, containing the term of (L-1)/2 in the component related to the index i on the numerator of the Fourier transform function) and the precoded And converting the L symbol vectors into OFDM signals.

의 역행렬로 표현되고, 여기서, i 및 j는 매트릭스의 행 및 열의 인덱스를 의미하며, 퓨리에 변환 함수의 분자 상의 인덱스 i와 관련된 컴포넌트에 (L-1)/2의 항을 포함할 수 있다.A method of receiving a DFT-s-OFDM receiver in a wireless communication system according to another aspect of the present invention for achieving the above object comprises: receiving a received signal and removing a cyclic prefix (CP), the circulation Performing N DFT operations on N symbol vectors from which the transposition is removed, and removing frequency samples for N symbol vectors on which DFT operation has been performed, thereby removing symbol samples of L-L is a natural number less than N- Including the step of outputting and performing an IDFT operation using a pruned IDFT matrix to generate a symbol vector of M symbols-M is a natural number greater than L by receiving L symbol vectors. However, the pruned IDFT matrix is

Represented by the inverse matrix of, where i and j mean the index of the row and column of the matrix, and may include the term of (L-1)/2 in the component related to the index i on the numerator of the Fourier transform function.

According to the DFT-s-OFDM transmitter and receiver of the present invention, the transmission signal has an effect of improving frequency efficiency while maintaining PAPR similar to that of the conventional pi/2-BPSK DFT-s-OFDM.

In addition, by performing zero tailing (zero tailing) can be transmitted and received without cyclic prefix in the multipath channel without loss of frequency efficiency, there is also an effect of reducing the out-of-band radiation.

1 is a block diagram showing a pi/2-BPSK DFT-s-OFDM transmission structure,
2 is a block diagram showing a pi/2-BPSK DFT-s-OFDM transmission structure equivalent to FIG. 1;
3 is a block diagram showing a pi/2-BPSK DFT-s-OFDM reception structure,
4 is a block diagram showing a frequency-efficient DFT-s-OFDM transmission structure according to an embodiment of the present invention,
5 is a block diagram showing a frequency-efficient DFT-s-OFDM reception structure according to an embodiment of the present invention,
6 is a block diagram showing a frequency-efficient zero tailing DFT-s-OFDM transmission structure using FIG. 4;
7 is a block diagram illustrating a base station and a terminal having a frequency-efficient DFT-s-OFDM transmission and reception structure according to an embodiment of the present invention.

The present invention can be applied to various changes and can have various embodiments, and specific embodiments will be illustrated in the drawings and described in detail.

However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from other components. For example, the first component may be referred to as a second component without departing from the scope of the present invention, and similarly, the second component may be referred to as a first component. The term and/or includes a combination of a plurality of related described items or any one of a plurality of related described items.

When an element is said to be "connected" or "connected" to another component, it is understood that other components may be directly connected to or connected to the other component, but there may be other components in between. It should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that no other component exists in the middle.

The terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as “include” or “have” are intended to indicate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, and that one or more other features are present. It should be understood that the existence or addition possibilities of fields or numbers, steps, operations, components, parts or combinations thereof are not excluded in advance.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. Terms such as those defined in a commonly used dictionary should be interpreted as having meanings consistent with meanings in the context of related technologies, and should not be interpreted as ideal or excessively formal meanings unless explicitly defined in the present application. Does not.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the overall understanding in describing the present invention, the same reference numerals are used for the same components in the drawings, and duplicate descriptions for the same components are omitted.

The following technologies include code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), and single carrier frequency division multiple access (SC-FDMA). It can be used in various wireless communication systems. CDMA may be implemented by radio technology such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA may be implemented with wireless technologies such as Global System for Mobile communications (GSM)/General Packet Radio Service (GPRS)/Enhanced Data Rates for GSM Evolution (EDGE). OFDMA may be implemented with wireless technologies such as IEEE 80211 (Wi-Fi), IEEE 80216e (WiMAX), IEEE 802-20, and Evolved UTRA (E-UTRA). UTRA is part of the Universal Mobile Telecommunications System (UMTS). The 3rd Generation Partnership Project (3GPP) long term evolution (LTE) is part of Evolved UMTS (E-UMTS) using E-UTRA, and adopts OFDMA in the downlink and SC-FDMA in the uplink. LTE-Advanced (LTE-A) is an evolution of 3GPP LTE.

Basically, a wireless communication system includes at least one base station (BS). Each base station provides communication services for a specific geographic area (generally called a cell). The cell can be further divided into a number of regions (called sectors). A user equipment (UE) may be fixed or mobile, and a mobile station (MS), a user terminal (UT), a subscriber station (SS), a wireless device (PDA), a personal digital assistant (PDA), and a wireless modem (wireless modem), handheld device (handheld device) can be called in other terms. A base station generally refers to a fixed station that communicates with a terminal, and may be called other terms such as an evolved-NodeB (eNB), a base transceiver system (BTS), and an access point.

Hereinafter, downlink (DL) means communication from a base station to a terminal, and uplink (UL) means communication from a terminal to a base station. In the downlink, the transmitter may be part of the base station, and the receiver may be part of the terminal. In the uplink, the transmitter may be part of the terminal, and the receiver may be part of the base station.

The wireless communication system may be any one of a multiple input multiple output (MIMO) system, a multiple input single output (MISO) system, a single input single output (SISO) system, and a single input multiple output (SIMO) system. The MIMO system uses a plurality of transmit antennas and a plurality of receive antennas. The MISO system uses multiple transmit antennas and one receive antenna. The SISO system uses one transmit antenna and one receive antenna. The SIMO system uses one transmit antenna and multiple receive antennas.

Hereinafter, the wireless communication system assumes a MIMO system. The transmit antenna means a physical or logical antenna used to transmit one signal or stream, and the receive antenna means a physical or logical antenna used to receive one signal or stream.

As a multi-antenna transmission/reception scheme for operation of a MIMO system, Space Time Block Code (STBC), Space Frequency Block Code (SFBC), Frequency switched transmit diversity (FSTD), Cyclic Delay Diversity (CDD), Space Multiplexing, transmit diversity, precoding vector switching (PVS), antenna selection, antenna virtualization, and time switched transmit diversity (TSTD) may be used.

In STBC, signals are transmitted separately in the time and space domains, and signals received for each antenna are determined by a maximum likelihood combining technique. SFBC is a technique that can secure both diversity gain and multi-user scheduling gain in a corresponding dimension by effectively applying selectivity in a spatial domain and a frequency domain. FSTD is a technique for classifying signals transmitted through multiple antennas by frequency, and TSTD is a technique for classifying signals transmitted through multiple antennas by time. CDD is a technique for obtaining diversity gain by using a path delay between transmission antennas. Spatial multiplexing is a technique of increasing data rates by transmitting different data for each antenna. Transmission diversity is a technique that increases the reliability of transmission by transmitting the same data from different antennas. PVS is a kind of transmission diversity technique, and is a method of obtaining a random beamforming gain by switching a precoding vector (weight) in a predetermined time, slot or symbol unit. Antenna selection is a technique of selecting an antenna for transmitting and receiving a signal according to a channel state, and antenna virtualization is a technique showing an effect of receiving a signal through a virtual antenna having a different number from the number of antennas of the transmitter in the receiver.

To clarify the description, 3GPP LTE/LTE-A and 5G (5th generation mobile communication service, which constructs a network that is hundreds of times faster than a 4G mobile communication network using an ultra-high-bandwidth frequency of 28 GHz) are mainly described. The technical idea is not limited to this.

1 is a block diagram illustrating a pi/2-BPSK DFT-s-OFDM transmission structure. As shown in FIG. 1, the pi/2-BPSK DFT-s-OFDM transmitter includes a constellation rotation (110), a DFT precoder (120), an OFDM modulator (130), and a cyclic prefix inserter (140). It can contain.

Referring to FIG. 1, a transmission/reception model of a general wireless communication environment follows the following equation.

Here, H is a Toeplitz matrix as a multipath channel, and N is an additive white Gaussian noise (AWGN) noise vector.

In the pi/2-BPSK DFT-s-OFDM transmitter, the coordinate rotator 110 receives M BPSK (Binary Phase Shift Keying) symbol vectors b . The coordinate rotator 110 rotates the coordinates of the received symbol vector with R(π/2) b . R(π/2) is defined by the following equation.

The pi/2-BPSK symbol that has passed through the coordinate rotator 110 is pre-coded in the DFT precoder 120 and then provided to the OFDM modulator 130. The DFT precoder 120 performs precoding using the M-point DFT matrix W _M. The components of W _M are defined as follows.

Here, M represents the number of input symbols and i,j represents the index of the matrix. The output of the DFT precoder 120 is input as a continuous subcarrier of the OFDM modulator 130.

OFDM modulator 130 performs an N-point IDFT on the precoded output symbol. At this time, N modulation symbols are input, and since N> M, an input of an unused IDFT may be set to O. After performing the N-point IDFT in the OFDM modulator 130, a cyclic prefix (CP) is inserted for every transport block, as in normal OFDM for N transport blocks.

FIG. 2 is a block diagram showing a pi/2-BPSK DFT-s-OFDM transmission structure equivalent to FIG. 1; The difference between the transmission structure of FIGS. 2 and 1 is that the coordinate rotator 110 and the DFT precoder 120 are made in a modified DFT precoder 210 which is a functional block.

의 M-point DFT 매트릭스를 사용하는데, 이는 좌표효전 효과를 합쳐서 DFT를 수행하도록 정의된다. 이는 다음과 같이 정의될 수 있다. 2, the modified DFT precoder 210 is

The M-point DFT matrix is used, which is defined to perform the DFT by combining the coordinate effect effects. It can be defined as:

3 is a block diagram illustrating a pi/2-BPSK DFT-s-OFDM reception structure. The pi/2-BPSK DFT-s-OFDM receiver may include a cyclic prefix canceller 310, a DFT operator 320, an equalizer 330, and an IDFT operator 340.

Referring to FIG. 3, the receiver may be viewed as a structure that performs the reverse process of the transmitter of FIG. 1 or 2. The cyclic prefix remover 310 removes cyclic prefixes from (N+N _C ) received blocks, and the DFT operator 320 performs N-point DFT(W _N ).

The output of the DFT operator 320 includes one received symbol, which is provided to the equalizer 330. The equalizer 330 may be implemented as a 1-tap channel equalizer. The equalizer 330 partially removes frequency samples from the N symbol vectors to compensate for frequency selectivity of the radio channel.

의 역행렬을 이용하여 변형된 IDFT 연산을 수행한다. Then, M symbol vectors are provided to the IDFT operator 340. IDFT operator 340 described above

The transformed IDFT operation is performed using the inverse matrix of.

4 is a block diagram showing a frequency-efficient DFT-s-OFDM transmission structure according to an embodiment of the present invention. As shown in FIG. 4, the DFT-s-OFDM transmitter according to an embodiment of the present invention includes a DFT precoder 410, a spectrum shaper 420, an OFDM modulator 430, and a cyclic prefix inserter ( 440).

Referring to FIG. 4, the OFDM modulator 430 and the cyclic prefix inserter 440 perform the same or similar functions as the OFDM modulator 320 and the cyclic prefix inserter 330 of FIG. 3.

로 표현가능하며, 다음과 같이 정의할 수 있다. The DFT precoder 410 performs precoding using a modified pruned DFT matrix obtained by pruning the modified DFT matrix. this is

It can be expressed as and can be defined as follows.

In the DFT precoder 410, using the above pruned DFT matrix, L symbols are output for M symbol inputs, where L is the number of subcarriers used as a natural number less than M. it means. That is, in the system of FIG. 2, M sub-carriers are used to transmit M BPSK symbols, but in the transmitter according to an embodiment of the present invention, L sub-carriers smaller than M are used when transmitting M BPSK symbols. It is possible to increase the frequency efficiency.

)을 곱한다. 이때, s는 L by 1 벡터로 다음과 같이 s_o, s₁, ... , s_L-1을 포함하는 L개의 계수로 이루어진다. The spectral shaper 420 uses a pruned transformed DFT matrix to generate a diagonal matrix () for the precoded output symbols.

). At this time, s is an L by 1 vector and consists of L coefficients including s _o , s ₁ , ..., s _L-1 as follows.

However, in the structure of the transmitter according to an embodiment of the present invention, not all arbitrary s are allowed. It is preferable to take s satisfying the following condition as a coefficient. The condition is expressed by the following equation (7) and (8).

At this time, Equation 7 is a condition for setting the power spectral density to be symmetric under the condition that the coefficients are symmetric.

When Equation 8 is satisfied, the Nyquist criterion that can freely transmit the BPSK symbol to ISI (Inter Symbol Interference) is satisfied, and the frequency efficiency increases and the reception performance does not deteriorate. do.

When using s that satisfies Equations 7, 8, there is no difference in reception performance, so the frequency efficiency is determined by the ratio of L and M. Frequency efficiency compared to a DFT-s-OFDM system using a conventional pi/2-BPSK symbol is shown in Equation (9).

For example, a system with M = 48 and L = 32 can send 1.5 times more symbols compared to the same bandwidth as the conventional system.

5 is a block diagram showing a frequency-efficient DFT-s-OFDM reception structure according to an embodiment of the present invention. As shown in FIG. 5, the DFT-s-OFDM receiver according to an embodiment of the present invention includes a cyclic prefix canceller 510, a DFT operator 520, an equalizer 530, and a spectrum shaper 540 and IDFT. It may include an operator (550).

Referring to FIG. 5, the cyclic prefix canceller 510 and the DFT operator 520 may perform the same functions as the cyclic prefix canceller 310 and the DFT operator 320 of FIG. 3. However, the equalizer 530 receives N received symbols and provides L outputs smaller than M to the spectrum shaper 540 instead of M.

At this time, the spectrum shaper 540 performs an operation corresponding to the operation of the spectrum shaper 420 of FIG. 4, and multiplies the truncation matrix based on coefficients satisfying Equations 7 and 8.

의 역행렬을 이용하여 IDFT를 수행하는 것이다. 이 경우, L 개의 입력에 대해 M개의 심볼이 출력된다. The IDFT operator 550 receives L symbols as an output of the spectrum shaper 540 and performs IDFT using a pruned transformed IDFT matrix. This is the previous DFT precoder 410 of Figure 4

IDFT is performed using the inverse matrix of. In this case, M symbols are output for L inputs.

FIG. 6 is a block diagram showing a frequency-efficient zero tailing DFT-s-OFDM transmission structure using FIG. 4. As shown in FIG. 6, the ZT DFT-s-OFDM transmitter according to an embodiment of the present invention may include a pruned modified DFT precoder 610, a spectrum shaper 620, and an OFDM modulator 630. have. That is, a structure in which a circulating anterior inserter is not necessarily required.

Referring to FIG. 6, a zero tailing technique using a transmission/reception structure that increases frequency efficiency may be added to the transmitter structure of FIG. 4. That is, M subcarriers are used to transmit the M BPSK symbols, and a total of (M _O -M) zeros are padded symbols. That is, (M _O -M) zero padded symbols are added to a symbol vector b based on a transmission symbol to be transmitted and input to the pruned modified DFT precoder 610. Then, the M symbols are output by an operation based on the transformed modified DFT matrix, and spectrum output is performed to obtain M output symbols. Then, N outputs may be finally generated by performing N-point IDFT by using the obtained M outputs and (NM) 0s as inputs.

The frequency efficiency of the ZT DFT-s-OFDM system and the conventional ZT DFT-s-OFDM system according to an embodiment of the present invention is expressed by Equation (10).

7 is a block diagram illustrating a base station and a terminal having a frequency-efficient DFT-s-OFDM transmission and reception structure according to an embodiment of the present invention.

Referring to FIG. 7, the base station 700 includes a processor (710: processor), a memory (720: memory), and an RF unit (730: radio frequency (RF) unit). The processor 710 implements the proposed function, process and/or method. The function of the receiver of FIG. 5 described above may be implemented by the processor 710. The memory 720 is connected to the processor 710, and stores various information for driving the processor 710. The RF unit 830 is connected to the processor 810, and transmits and/or receives wireless signals.

The terminal 800 includes a processor 810, a memory 820, and an RF unit 830. The processor 810 includes a plurality of symbols in the time domain, a control area (PUCCH area) in which only control information can be transmitted in the frequency domain, and a data area (PUSCH area) in which uplink control information and data can be transmitted together. ), and transmits uplink control information and data to the base station 700 in the PUSCH region of the subframe. At this time, the uplink control information may be transmitted through a plurality of transmission antennas. As described above, the MIMO transmission technique or other MIMO transmission technique used for data transmission may be used for uplink control information according to the type. In addition, the same precoding used for data transmission may be applied and then transmitted. In addition, the uplink control information may be transmitted by repeating the same control information by a number of ranks or multiplexing with different control information. The functions of the transmitters 400 and 600 of FIG. 4 or 6 described above may be implemented by the processor 810. The memory 820 is connected to the processor 810, and stores various information for driving the processor 810. The RF unit 830 is connected to the processor 810, and transmits and/or receives wireless signals.

The processors 710 and 810 may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, data processing devices, and/or converters that convert baseband signals and radio signals to each other. The memories 720 and 820 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and/or other storage devices. The RF units 730 and 830 may include one or more antennas that transmit and/or receive wireless signals. When the embodiment is implemented in software, the above-described technique may be implemented as a module (process, function, etc.) performing the above-described function. The modules are stored in memories 720 and 820 and can be executed by processors 710 and 810. The memories 720 and 820 may be inside or outside the processors 710 and 810, and may be connected to the processors 710 and 810 by various well-known means.

Although described above with reference to the drawings and examples, the protection scope of the present invention is not meant to be limited by the drawings or examples, and those skilled in the art will think of the present invention described in the following claims And it will be understood that various modifications and changes may be made to the present invention without departing from the scope.

Claims (13)

In a DFT-s-OFDM transmitter in a wireless communication system,
A DFT precoder that receives M BPSK symbol vectors and precodes them using a pruned DFT matrix to use subcarriers of L-L is a natural number less than M. DFT matrix

, Where i and j mean the index of the row and column of the matrix; And
Includes an OFDM modulator for converting the pre-coded L symbol vectors into OFDM signals,
The pruned DFT matrix is

DFT-s-OFDM transmitter in a wireless communication system calculated with. delete According to claim 1,
A diagonal matrix (L) of the precoded L symbol vectors

) (diagonal matrix) DFT-s-OFDM transmitter in a wireless communication system further comprising a spectrum shaper (spectrum shaper). The method of claim 3,
The diagonal matrix is a DFT-s-OFDM transmitter in a wireless communication system that is a matrix of L coefficients including s ₀ to s _L-1 as LX 1 vectors. The method of claim 4,
DFT-s-OFDM transmitter in a wireless communication system in which the coefficients of the diagonal matrix are symmetrically set to make power spectral density symmetric. The method of claim 5,
The coefficients of the diagonal matrix are DFT-s-OFDM transmitters in a wireless communication system satisfying the following condition of the first equation.

The method of claim 6,
The coefficients of the diagonal matrix are DFT-s-OFDM transmitters in a wireless communication system satisfying the following condition of the second equation.

In a DFT-s-OFDM transmitter in a wireless communication system,
Pruned DFT matrix is used to use M subcarriers after receiving the zero padded symbols of M BPSK symbol vectors and (M _O -M)-M _O is a natural number greater than M Precoding DFT precoder, where the pruned DFT matrix is

, Where i and j mean the index of the row and column of the matrix;
An OFDM modulator for converting the precoded M symbol vectors into an OFDM signal; And
A zero padding symbol provider providing the (M _O -M) zero padded symbols to the DFT precoder,
The pruned DFT matrix is

DFT-s-OFDM transmitter in a wireless communication system calculated with. According to claim 1,
A DFT-s-OFDM transmitter in a wireless communication system further comprising a cyclic prefix inserter to insert a cyclic prefix (CP) into the OFDM signal. In the DFT-s-OFDM receiver in a wireless communication system,
A cyclic prefix remover that receives a received signal and removes a cyclic prefix (CP);
An N-point DFT operator performing N DFT operations on N symbol vectors from which the cyclic prefix is removed;
An equalizer that outputs symbol vectors of L-L is a natural number less than N by removing frequency samples for N symbol vectors that have undergone DFT calculation; And
Includes an IDFT operator that performs IDFT calculation using a pruned IDFT matrix to generate a symbol vector of M symbols-M is a natural number greater than L, receiving L symbol vectors,
The pruned IDFT matrix is

Is represented by the inverse matrix, where i and j mean the index of the row and column of the matrix,
The pruned IDFT matrix is

DFT-s-OFDM receiver in a wireless communication system calculated with an inverse matrix of. The method of claim 10,
Further comprising a spectral shaper between the equalizer and the IDFT operator,
The spectral shaper is a diagonal matrix of the L symbol vectors (

DFT-s-OFDM receiver in a wireless communication system that multiplies (diagonal matrix). A method for transmitting a DFT-s-OFDM transmitter in a wireless communication system,
Precoding using a pruned DFT matrix to use the subcarriers of L-L is a natural number less than M-receiving M BPSK symbol vectors, wherein the pruned DFT matrix The

, Where i and j mean the index of the row and column of the matrix; And
And converting the precoded L symbol vectors into OFDM signals,
The pruned DFT matrix is

DFT-s-OFDM transmission method in a wireless communication system calculated by. A method for receiving a DFT-s-OFDM receiver in a wireless communication system,
Removing a cyclic prefix (CP) by receiving a received signal;
Performing N DFT operations on the N symbol vectors from which the cyclic prefix is removed;
Outputting a symbol vector of L-L is a natural number less than N by removing frequency samples for N symbol vectors that have undergone DFT calculation; And
And performing IDFT operations using a pruned IDFT matrix to generate a symbol vector of M symbols, where M is a natural number greater than L, after receiving L symbol vectors,
The pruned IDFT matrix is

Is represented by the inverse matrix, where i and j mean the index of the row and column of the matrix,
The pruned IDFT matrix is

DFT-s-OFDM reception method in a wireless communication system calculated with an inverse matrix of.

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