WO2017126897A1 - Method and transmission apparatus for multiple access in wireless communication system - Google Patents
Method and transmission apparatus for multiple access in wireless communication system Download PDFInfo
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- WO2017126897A1 WO2017126897A1 PCT/KR2017/000638 KR2017000638W WO2017126897A1 WO 2017126897 A1 WO2017126897 A1 WO 2017126897A1 KR 2017000638 W KR2017000638 W KR 2017000638W WO 2017126897 A1 WO2017126897 A1 WO 2017126897A1
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- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
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- the present invention relates to a multiple access method and a transmission apparatus for multiple access in a wireless communication system, and more particularly, to a multiple access method and multiple access in a wireless communication system capable of providing ultra low delay, high reliability, and high capacity services. It relates to a transmission device for.
- ultra low latency high reliability high capacity service requires a wireless section delay time of less than 1ms, a reliability condition of 99.999%, and a data transmission capacity of up to 100Mbps.
- Each user needs a waveform configuration that is suitable for different mobility and channel environments, and the various waveforms configured in this way must coexist efficiently. If multiple antennas are used at the transceiver, three-dimensional waveform configuration of time, frequency, and space can be made for each user's characteristics. Therefore, it is necessary to provide the required reliability by reducing interference between waveforms and increasing diversity. do.
- Non-orthogonal multiple access schemes may be used for resources allocated to time, frequency, and space, and non-orthogonality may change according to time or channel environment.
- OFDM Orthogonal Frequency Division Multiplexing
- CP cyclic prefix
- OFDM waveforms can solve multipath fading using cyclic prefix (CP), and can implement waveform modulation with low complexity through fast Fourier transform.
- CP cyclic prefix
- OFDM waveforms have a large out-of-band emission in a non-orthogonal situation, when used with waveforms having different parameters, interference occurs and is inefficient.
- the disadvantage is that it must be used as a form.
- 5G mobile communication research institutes, telecommunication operators, and manufacturers have proposed multicarrier waveforms using filters to improve the shortcomings of the OFDM waveform.
- METIS-II a project undertaken by 5GPPP, an alliance for developing 5G technology, considers FBMC (Filter-Bank Multi-Carrier modulation) waveform as a radio interface.
- FBMC Fan-Bank Multi-Carrier modulation
- UFMC Universal Filtered Multi-Carrier
- f-OFDM filtered-OFDM
- the multicarrier waveform using the filter is more asynchronous than the OFDM waveform, and even when the waveform parameters are different, the waveforms can coexist efficiently without affecting interference.
- the present invention is to provide a multiple access method and a transmission device for multiple access in a wireless communication system capable of providing ultra low delay, high reliability and high capacity services.
- a multiple access method is provided in a wireless communication system that applies a selected pulse shaping filter to a sample that is the result of Fourier transforming the sub-symbols into a frequency domain.
- a resource allocator for allocating resources for a plurality of user terminals, space and frequency;
- a Fourier transform unit comprising a plurality of sub-symbols, and performing a discrete Fourier transform on the spatial units of the transmission symbols transmitted according to the allocated spatial and frequency resources;
- a filtering unit for selecting a pulse shaping filter according to an arrangement position of the allocated frequency resource and applying the selected pulse shaping filter to a sample that is a result of Fourier transform of the sub-symbols in the frequency domain.
- the interference between subcarriers can be reduced by selecting and using the pulse shaping filter according to the arrangement position of resources allocated for each frequency, without using a fixed pulse shaping filter.
- 1 and 2 are diagrams for explaining the GFDM.
- FIG. 3 is a diagram illustrating an allocation map of a resource block according to an embodiment of the present invention.
- 4 and 5 are diagrams illustrating filtered subcarriers according to the resource block allocation map of FIG. 3.
- FIG. 6 is a diagram for describing spatial multiplexing access according to the resource block allocation map of FIG. 3.
- FIG. 7 is a view for explaining a transmission system according to an embodiment of the present invention.
- FIG. 8 is a view for explaining a receiving system according to an embodiment of the present invention.
- FIG. 9 is a diagram illustrating a transmission device for multiple access according to an embodiment of the present invention.
- FIG. 10 is a diagram illustrating a multiple access method according to an embodiment of the present invention.
- FIG. 11 is a diagram showing throughput and throughput simulation results of GFDM and OFDM according to the present invention.
- FIG. 12 is a diagram illustrating a pseudo-code for explaining a multiple access method according to another embodiment of the present invention.
- the present invention proposes a new method of multiple access in a wireless communication system.
- the multiple access method according to the present invention will be referred to as Universal Spatio-Frequency Division Multiple Access (USFDMA).
- USFDMA Universal Spatio-Frequency Division Multiple Access
- the multiple access method according to the present invention provides high beamforming resolution and good out-of-band channel performance under ultra low delay, high reliability, and high capacity service requirements, and exhibits higher frequency efficiency than GFDM and OFDM.
- 1 and 2 are diagrams for explaining the GFDM.
- the GFDM transmits data in the form of a data block including K subcarriers and M subsymbols, as shown in FIG. 1.
- the data block of the GFDM shown in FIG. 1 includes one transmission symbol composed of a plurality of subsymbols, and one subcarrier transmits a plurality of subsymbols in the GFDM.
- All data to be sent in the GFDM is modulated by the GFDM transmission matrix A and then added with a Cyclic Prefix (CP) to minimize the effect of delay spread of the channel and remove the inter-block interference of the GFDM, such as OFDM.
- CP Cyclic Prefix
- the GFDM uses a pulse shaping filter fixed in the frequency domain to perform filtering on a sample that is a result of frequency conversion of a subsymbol.
- Frequency equalization filtering and spatial filtering are performed in units of transmission symbols.
- Non-orthogonal waveforms generated by pulse shaping filtering in GFDM cause subcarrier interference to increase BER.
- the present invention proposes a multiple access method capable of satisfying ultra low delay, high reliability, and high capacity service requirements by reducing interference between subcarriers.
- the interference between subcarriers can be reduced by selecting and using a pulse shaping filter according to an arrangement position of resources allocated for each frequency, without using a fixed pulse shaping filter.
- the multiple access method according to the present invention can provide high beamforming resolution and excellent out-of-band channel performance by applying a frequency filter and a spatial filter on a sample basis.
- the multiple access method according to the present invention may be performed in a transmission apparatus for multiple access, and the transmission apparatus may be a base station.
- FIG. 3 illustrates an allocation map of a resource block according to an embodiment of the present invention
- FIGS. 4 and 5 illustrate filtered subcarriers according to the resource block allocation map of FIG. 3.
- 6 is a diagram for describing a spatial multiplexing connection according to the resource block allocation map of FIG. 3.
- FIG. 3 a case in which four subcarriers and four substreams are allocated to four user terminals is described as an embodiment. However, resource allocation may be variously performed according to an embodiment.
- the base station allocates spatial and frequency resources for each user terminal as shown in FIG. 3 in consideration of resource conditions, channel conditions, service requirements, and the like.
- the subcarrier corresponds to the frequency resource and the substream corresponds to the spatial resource.
- data for the first user terminal user1 is transmitted through the first to third subcarriers 301, 302, and 303, and simultaneously through the first and second substreams 311 and 312. do.
- the data for the fourth user terminal user4 is transmitted through the fourth subcarrier 304 and simultaneously transmitted through the first to fourth substreams 311, 312, 313, and 314.
- the base station transmits a transmission symbol to a user terminal according to the allocated resource, the transmission symbol is composed of a plurality of sub-symbols.
- the base station performs a discrete Fourier transform for each spatial unit, that is, for each substream, and the sub-symbols are represented by different frequency components in the frequency domain according to the Fourier transform.
- the base station selects, in spatial units, the pulse shaping filter according to the placement position of the allocated frequency resource, and applies the selected pulse shaping filter to the sample resulting from Fourier transform of the sub-symbols into the frequency domain.
- the discrete Fourier transform is an M-point Fast Fourier Transform (FFT), which represents different frequency components for each subsymbol as a result of the Fourier transform, and M corresponds to the number of subsymbols.
- FFT Fast Fourier Transform
- FIG. 4 illustrating the subcarriers filtered for each substream, it can be seen that four pulse shaping filters are applied.
- the filtered subcarriers of FIG. 4 are expressed for one sample group in which filtering is performed at the same time. Since a plurality of sub symbols are transmitted through one subcarrier, pulse shaping filtering is performed on the plurality of sample groups, respectively. .
- each subsymbol in the time-space-frequency domain corresponds to a symbol duration in the time domain.
- Samples are generated in the frequency domain for each subsymbol for, and pulse shaping filtering is performed for each sample group.
- the pulse shaping filter is selected from a Square-Root Raised Cosine (SRRC) filter 440, a left-squeezed SRRC filter 410, a right-squeezed SRRC filter 430, and a square filter 420.
- the pulse shaping filter may be selected depending on whether the allocation index of the frequency resources for the same user terminal is continuous.
- the frequency response of the SRRC filter 440 is trapezoidal, and the frequency response of the rectangular filter 420 is rectangular.
- the frequency response of the left squeeze SRRC filter 410 has a rectangular shape on the right side
- the frequency response of the light squeeze SRRC filter 430 has a square shape on the left side.
- the base station performs pulse shaping filtering on the samples in the order of left squeeze SRRC filter and light squeeze SRRC filter when the allocation index of the frequency resource for the same user terminal is continuous, and when the number of consecutive allocation indexes is 3 or more, Pulse shaping filtering may be performed on the sample by placing at least one square filter between the squeeze SRRC filter and the light squeeze SRRC filter.
- the allocation indexes may be allocated in order from the first subcarrier to the fourth subcarrier.
- the frequency resources for the first user terminal that is, the subcarriers are sequentially allocated, are applied to the samples in the order of left squeeze SRRC filter 410 and light squeeze SRRC filter 430, three subcarriers are applied. Since are allocated consecutively, the square filter 420 is disposed between the left squeeze SRRC filter 410 and the light squeeze SRRC filter 430. If four subcarriers are sequentially allocated to the first user terminal, two rectangular filters may be disposed between the left squeeze SRRC filter and the right squeeze SRRC filter.
- the left squeeze SRRC filter 410 and the light squeeze SRRC filter 430 are sequentially applied to the sample without the quadrangle filter 420.
- the base station performs pulse shaping filtering on the sample using the SRRC filter.
- the SRRC filter 440 is applied to the fourth user terminal as shown in FIG. 4.
- the filtered signal in the frequency domain is transmitted to the user terminal through different substreams, as shown in FIG. 6.
- 6 (a) to 6 (b) show first to fourth substreams transmitted through the first to fourth subcarriers, respectively.
- Symbols for the first and second user terminals to which the first subcarrier is allocated are transmitted to the first and second user terminals through the first to fourth substreams as shown in FIG. Referring to FIG. 3, symbols for a first user terminal are transmitted through first and second substreams each having different beams, and symbols for the second user terminal are each formed with different beams. And a fourth substream.
- each subcarrier is allocated is transmitted to the user terminal through the first to fourth substreams, as shown in FIGS. 6 (b) to 6 (d).
- the base station performs filter shaping filtering, and may perform frequency equalization filtering and spatial filtering together. Frequency equalization filtering and spatial filtering are also performed on a sample basis, and the frequency equalization filter and the spatial filter may be determined according to channel conditions for each user terminal.
- FIG 7 is a view for explaining a transmission system according to an embodiment of the present invention
- Figure 8 is a view for explaining a reception system according to an embodiment of the present invention.
- FIG. 7 illustrates a series of transmission processing procedures performed at a base station.
- FIG. 7 a case in which resource blocks are allocated as shown in FIG. 3 will be described as an embodiment.
- 8 illustrates a series of reception processing procedures performed in a user terminal, and in FIG. 8, a reception system for a first user terminal is described as an embodiment.
- the base station arranges the data block according to the allocated resource as shown in FIG. 3 (710). That is, data blocks consisting of M sub-symbols are arranged according to subcarriers and substreams allocated for each user terminal.
- the data block corresponds to the above-described transmission symbol.
- the sub-symbol allocated to each block may be QAM data as an embodiment, and may be represented by a vector as shown in [Equation 1].
- different modulation schemes may be applied for each subsymbol according to an embodiment, and each subsymbol may be data according to at least one modulation scheme.
- u represents the index of the data block
- k represents the index of the subcarrier
- l represents the index of the substream.
- u for the data block 711 may be 4
- k may be 4
- l may be 1.
- the base station performs 720 an M-point FFT in units of space, that is, in units of substreams.
- the Fourier transform result is arranged for each subcarrier index for one substream, and the Fourier transform result for each substream is arranged for each substream index (730).
- i an index for the user terminal
- silver represents the l-th column of the identity matrix of size, to be.
- the base station multiplies (740) a power allocation parameter (Q) for compensating for the attenuation of the effective channel for the frequency domain signal for each substream, and the sample is the result of Fourier transforming the sub-symbols into the frequency domain. Filtering is performed (750).
- the power allocation parameter Q is described in more detail in FIG. 12.
- the base station is a frequency filter (frequecy filter, ) And spatial filters, Filtering is performed on a per-sample basis.
- the frequency filter is a frequency domain equalizer (frequecy domain equalizer, ) And pulse shaping filter ).
- the base station selects a pulse shaping filter according to an arrangement position of frequency resources allocated to a user terminal, that is, an allocation index of a subcarrier, in space units, and may select one of the four filters described above. Pulse shaping filtering is performed on the samples in units of substreams using the selected filter.
- the base station may perform frequency equalization filtering and pulse shaping filtering together with the pulse shaping filtering on a sample basis.
- the base station determines the frequency equalization filter and the spatial filter according to the channel state between user terminals, and may determine the frequency equalization filter and the spatial filter in consideration of the channel state for each duration of the subsymbol.
- the base station may determine the spatial filter in consideration of the channel status for each substream, and the spatial filter is a filter for beamforming as a filter for precoding.
- the base station performs an MK-point IFFT to convert a signal in the frequency domain into a signal in the time domain (760), inserts a CP or CS (Cyclic Suffix) according to the channel state, and transmits the signal to the user terminal (770). do.
- the signal in the time domain can be obtained using [Equation 3].
- N UE is the number of user terminals, Denotes a power allocation parameter.
- filtering may be performed by multiplying the frequency filter vector and the spatial filter vector for all samples MK in the frequency domain.
- IFFT and CP or CS insertion may be performed in the same manner as GFDM, a detailed description thereof will be omitted.
- the signal converted into the time domain is transmitted to the user terminal, and the user terminal may recover the QAM data symbol from the received signal as shown in FIG. 8.
- the processing of the received signal proceeds in the reverse order of the processing of the transmission signal.
- a first user terminal removes 810 a CP or a CS from a received signal Y u .
- the frequency filter in the frequency domain ( )
- spatial filter ( ) Demodulates the frequency domain signal (830).
- the M-point IFFT is performed to restore the QAM data symbols in the time domain (840).
- Frequency filter is pulse shaping filter ( ) And frequency equalization filter ( The filtering process is the same as that of the transmission signal.
- FIG. 9 is a diagram illustrating a transmission device for multiple access according to an embodiment of the present invention.
- the transmission apparatus includes a resource allocator 910, a Fourier transform unit 920, and a filtering unit 930.
- the resource allocator 910 allocates resources for a plurality of user terminals by space and frequency, and may allocate them as shown in FIG. 3 as an embodiment.
- the Fourier transform unit 920 is composed of a plurality of sub-symbols and performs discrete Fourier transform on a space unit with respect to transmission symbols transmitted according to the allocated space and frequency resources.
- the filtering unit 930 selects a pulse shaping filter according to an arrangement position of allocated frequency resources in spatial units, i.e., in a substream unit, and selects a pulse shaping filter selected for a sample that is a result of Fourier transform of a sub-symbol into a frequency domain. Apply.
- the filtering unit 930 performs precoding on each sample, and according to an embodiment, may include a frequency filtering unit and a spatial filtering unit.
- the frequency filter performs filtering on the sample using a pulse shaping filter and a frequency equalization filter. Filtering may be performed by multiplying the frequency response of each sample and the pulse shaping filter, the frequency response of the frequency equalization filter in the frequency domain.
- the spatial filter also performs filtering on a sample basis.
- the samples precoded by the filtering unit 930 are converted into signals in the time domain and then transmitted to the user terminal.
- Pulse shaping filtering may be performed as described in FIGS. 3 to 7.
- the transmission apparatus is characterized in that frequency equalization filtering and spatial filtering are performed on a sample basis as compared with GFDM which performs frequency equalization filtering and spatial filtering on a transmission symbol basis. Detailed description of the filtering will be omitted.
- FIG. 10 is a diagram illustrating a multiple access method according to an embodiment of the present invention.
- the multiple access method of the above-described transmission apparatus is described as an embodiment.
- the transmission apparatus allocates resources for a plurality of user terminals by space and frequency (S1010).
- S1020 a Discrete Fourier Transform is performed for each transmission symbol that is composed of a plurality of sub-symbols and is transmitted according to the allocated spatial and frequency resources.
- the discrete Fourier transform is an M-point FFT, where M corresponds to the number of sub-symbols.
- the modulation scheme is determined for each sub symbol, and the sub symbol may be, for example, a QAM data symbol.
- the transmitting device may apply a frequency filter and a spatial filter to the Fourier transform result, and apply the frequency filter and the spatial filter to the sample that is the result of the Fourier transform of the sub-symbol into the frequency domain.
- the frequency filter includes a pulse shaping filter and a frequency equalization filter.
- the transmitting apparatus selects a pulse shaping filter according to the arrangement position of the allocated frequency resource in units of space, and applies the selected pulse shaping filter to the sample resulting from Fourier transform of the sub-symbols in the frequency domain (S1030). do.
- the transmission device may select a pulse shaping filter from an SRRC filter, a left squeeze SRRC filter, a light squeeze SRRC filter, and a square filter.
- the transmitting device may apply the frequency equalization filter and the spatial filter according to the channel state of the user terminal to the sample.
- the modulation index and the spatial filter may be simultaneously determined so that the power for the transmission symbol is minimized.
- the transmission apparatus may determine the frequency, the spatial filter and the modulation index to minimize the transmission power, which will be described in detail with reference to FIG. 12.
- FIG. 11 is a diagram showing throughput and throughput simulation results of GFDM and OFDM according to the present invention.
- FIG. 11 assumes that each user belongs to a Rayleigh fading channel environment having the same distance attenuation from one base station, and is divided in half into users having high mobility (500 km / s) and low mobility (0 km / s).
- a simulation result in a condition in which USFDMA and GFDM coexist with waveforms having different symbol lengths according to mobility is shown. Since OFDM symbols of different lengths cannot coexist due to low out-of-band (OOB) performance, the experiments are divided into long symbols (OFDM Long) and short symbols (OFDM Short).
- the center frequency is 5Ghz
- the bandwidth is 80MHz
- the interval between subcarriers is 16.875KHz.
- the long symbol uses 8192 FFT size and the short symbol uses 1024 FFT size.
- FIG. 12 is a diagram illustrating a pseudo-code for explaining a multiple access method according to another embodiment of the present invention.
- FIG. 12 a method for minimizing power required for transmitting a transmission symbol while satisfying a data transmission capacity condition and a reliability condition required for a mobile communication service is described.
- the present invention provides a space-frequency filter so that minimum transmission power can be used while satisfying data transmission capacity conditions and reliability conditions. ) And a modulation index.
- the space-frequency filter is a precoder, and according to the space-frequency filter determined by the present invention, the transmission symbols are precoded and transmitted to the user terminal, and bits allocated to frequency-spatial resources by the modulation index determined by the present invention. The number is determined.
- the modulation index is a parameter indicating how many bits can be stored per symbol and indicates the number of bits allocated to frequency-space resources (k, l).
- the transmission apparatus first determines the space-frequency filter so that the reliability condition according to the modulation index pre-assigned for each space-frequency resource is satisfied, and at the same time, data can be transmitted with the minimum transmission power.
- a space-frequency filter may be determined.
- the transmission power P corresponds to the power allocation parameter Q described above.
- Whether the reliability condition according to the modulation index is satisfied may be calculated using SINR.
- Reliability conditions Calculated than SINR ( If) is large, it can be determined that the reliability condition is satisfied. Since the data to be transmitted is determined according to the modulation index, and the noise may be determined according to the channel state with the user terminal, the SINR to be compared with the reliability condition may be calculated. At this time, since the SINR is also determined according to the space-frequency filter, the transmission apparatus according to the present invention calculates the SINR and the transmission power for various space-frequency filters, satisfying the reliability conditions and simultaneously using the minimum power. The frequency filter can be determined.
- a space-frequency filter corresponding to the minimum transmission power that satisfies the reliability condition may be determined as the solution of Equation 4.
- the spatial-frequency filter may be determined according to the channel state.
- the transmitting device may determine the spatial-frequency filter capable of minimizing the transmission power while considering the channel state.
- transmitting device space meet the user terminal by data transmission capacity conditions in the effective channel is determined by the combination of the frequency filter (b i) - space for frequency resource-frequency when the filter is given, channels, and spaces At the same time, the modulation index is determined for each space-frequency resource so that the transmission symbol can be transmitted with the minimum power.
- the transmission apparatus may determine a modulation index for each space-frequency resource, as shown in [Equation 5].
- the transmission apparatus may determine whether the data transmission capacity condition for each user terminal is satisfied while increasing the modulation index by one from the initial value. As the modulation index increases, the rate increases, which may increase the likelihood that the data transmission capacity condition is satisfied.
- the transmission apparatus determines a modulation index such that the data transmission capacity condition is satisfied in the effective channel according to the determined space-frequency filter as described above, and simultaneously determines the modulation index so that the transmission symbol can be transmitted at the minimum power. do.
- the transmission apparatus can determine the spatial-frequency filter and the modulation index satisfying the equations (4) and (5) at the same time.
- the transmission apparatus determines a frequency filter and a spatial filter that minimize transmission power by using a preset modulation index for frequency and spatial resources, and uses the frequency filter and spatial filter determined as described above.
- the modulation index may be updated to minimize the transmission power.
- the updated modulation index can then be used to determine the space-frequency filter.
- the spatial-frequency filter and the modulation index may be differently determined for each subsymbol, and thus different transmission powers may be allocated and transmitted for each subsymbol. have.
- a method of determining the above-described spatial-frequency filter and modulation index is represented by a pseudo code as shown in FIG. 12.
- the technical contents described above may be embodied in the form of program instructions that may be executed by various computer means and may be recorded in a computer readable medium.
- the computer readable medium may include program instructions, data files, data structures, etc. alone or in combination.
- Program instructions recorded on the media may be those specially designed and constructed for the purposes of the embodiments, or they may be of the kind well-known and available to those having skill in the computer software arts.
- Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks.
- Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like.
- the hardware device may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.
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Abstract
Disclosed are multiple access method and apparatus capable of providing a service having minimum latency and high reliability and high throughput in a wireless communication system. The multiple access method according to the present invention comprises the steps of: allocating resources for a plurality of user terminals by space and frequency; carrying out discrete Fourier transforms, for each space, of transmission symbols which comprise a plurality of sub-symbols and which are transmitted in accordance with the allocated space and frequency resource; and applying frequency and space filters to the results of the Fourier transforms, wherein the step for applying frequency and space filters selects, for each space, a pulse-shaping filter in accordance with the location of the allocated frequency resource, and applies the selected pulse-shaping filter to the sample which is a result of a sub-symbol Fourier transformed into a frequency domain.
Description
본 발명은 무선 통신 시스템에서 다중 접속 방법 및 다중 접속을 위한 전송 장치에 관한 것으로서, 보다 상세하게는 초저지연, 고신뢰 및 고용량의 서비스를 제공할 수 있는 무선 통신 시스템에서의 다중 접속 방법 및 다중 접속을 위한 전송 장치에 관한 것이다. The present invention relates to a multiple access method and a transmission apparatus for multiple access in a wireless communication system, and more particularly, to a multiple access method and multiple access in a wireless communication system capable of providing ultra low delay, high reliability, and high capacity services. It relates to a transmission device for.
5G(5세대) 이동통신에 대한 다양한 연구가 여러 연구기관을 통해 진행됨에 따라 앞으로 새롭게 등장하게 될 것으로 예상되는 서비스들이 구체화 되고 있으며, 이러한 서비스를 지원하기 위한 요구사항 또한 함께 정리되고 있다. 5G 이동통신의 새로운 서비스 카테고리로서 초저지연 고신뢰 고용량 서비스는, 1ms 이내의 무선 구간 지연시간과 99.999%의 신뢰도 조건 및 최대 100Mbps 급의 데이터 전송 용량을 요구한다.As various researches on 5G (5th generation) mobile communication are conducted through various research institutes, services that are expected to emerge in the future are being specified, and requirements for supporting such services are also summarized. As a new service category of 5G mobile communication, ultra low latency high reliability high capacity service requires a wireless section delay time of less than 1ms, a reliability condition of 99.999%, and a data transmission capacity of up to 100Mbps.
위와 같은 서비스 조건을 달성하기 위해서는 다음과 같은 요구사항을 만족시켜야 한다. 각 사용자 별로 다른 이동성 및 채널환경에 맞는 웨이브폼 구성이 필요하며 이렇게 구성된 여러 웨이브폼(waveform)들이 효율적으로 공존할 수 있어야 한다. 송수신단에서 다수의 안테나를 활용하는 경우 각 사용자 특성에 맞는 시간, 주파수, 공간의 3차원 웨이브폼 구성이 가능하므로, 이를 통해 웨이브폼 간의 간섭을 낮추고 다이버시티를 높여 요구되는 신뢰성을 제공할 수 있어야 한다. 시간, 주파수, 공간으로 할당되는 자원들에 대하여 비직교 다중접속 방식이 사용될 수 있으며 시간에 따라 또는 채널 환경에 따라 비직교성이 변화할 수도 있다. In order to achieve the above service conditions, the following requirements must be satisfied. Each user needs a waveform configuration that is suitable for different mobility and channel environments, and the various waveforms configured in this way must coexist efficiently. If multiple antennas are used at the transceiver, three-dimensional waveform configuration of time, frequency, and space can be made for each user's characteristics. Therefore, it is necessary to provide the required reliability by reducing interference between waveforms and increasing diversity. do. Non-orthogonal multiple access schemes may be used for resources allocated to time, frequency, and space, and non-orthogonality may change according to time or channel environment.
현재 상용 이동통신 시스템인 IMT-Advanced 에서는 직교 주파수 분할 다중화 (Orthogonal Frequency Division Multiplexing, OFDM) 웨이브폼을 사용한다. OFDM 웨이브폼은 주기적 전치 부호 (cyclic prefix, CP)를 사용하여 다중경로 페이딩 (multipath fading)을 해결할 수 있고, 웨이브폼 변조를 고속 푸리에 변환(Fast Fourier transform)을 통해 낮은 복잡도로 구현할 수 있다는 장점을 가지고 있다. 그러나 OFDM 웨이브폼은 비직교(non-orthogonal) 상황에서 대역 외 방출(out-of-band emission)의 크기가 크기 때문에 서로 다른 파라미터를 갖는 웨이브폼과 같이 사용하는 경우 간섭이 발생하여 비효율적이므로 단일 웨이브폼으로 사용하여야 한다는 단점이 있다.Currently, IMT-Advanced, a commercial mobile communication system, uses Orthogonal Frequency Division Multiplexing (OFDM) waveforms. OFDM waveforms can solve multipath fading using cyclic prefix (CP), and can implement waveform modulation with low complexity through fast Fourier transform. Have. However, because OFDM waveforms have a large out-of-band emission in a non-orthogonal situation, when used with waveforms having different parameters, interference occurs and is inefficient. The disadvantage is that it must be used as a form.
5세대 이동통신 관련 연구기관이나 통신사업자, 제조사에서는 이러한 OFDM 웨이브폼의 단점을 개선하기 위하여 필터를 사용하는 다중반송파(multicarrier) 웨이브폼을 제시하고 있다. 5G 기술 개발을 위한 연합기구인 5GPPP 가 진행하는 프로젝트 METIS-II 에서는FBMC(Filter-Bank Multi-Carrier modulation) 웨이브폼을 무선 인터페이스로 고려하고 있으며, 이외에도 GFDM(Generalized Frequency Division Multiplexing), UFMC(Universal Filtered Multi-Carrier), f-OFDM (filtered-OFDM) 등이 연구되고 있다. 5G mobile communication research institutes, telecommunication operators, and manufacturers have proposed multicarrier waveforms using filters to improve the shortcomings of the OFDM waveform. METIS-II, a project undertaken by 5GPPP, an alliance for developing 5G technology, considers FBMC (Filter-Bank Multi-Carrier modulation) waveform as a radio interface. In addition, GFDM (Generalized Frequency Division Multiplexing) and UFMC (Universal Filtered) Multi-Carrier) and f-OFDM (filtered-OFDM) have been studied.
이와 같이 필터를 사용하는 다중반송파 웨이브폼은 OFDM 웨이브폼에 비해 비동기성에 강하며 웨이브폼 파라미터가 서로 다른 경우에도 웨이브폼들이 간섭의 영향 없이 효율적으로 공존하는 것이 가능하다.As such, the multicarrier waveform using the filter is more asynchronous than the OFDM waveform, and even when the waveform parameters are different, the waveforms can coexist efficiently without affecting interference.
본 발명은 초저지연, 고신뢰 및 고용량의 서비스를 제공할 수 있는 무선 통신 시스템에서의 다중 접속 방법 및 다중 접속을 위한 전송 장치를 제공하기 위한 것이다.The present invention is to provide a multiple access method and a transmission device for multiple access in a wireless communication system capable of providing ultra low delay, high reliability and high capacity services.
상기한 목적을 달성하기 위해 본 발명의 일 실시예에 따르면, 복수의 사용자 단말에 대한 자원을, 공간 및 주파수 별로 할당하는 단계; 복수의 서브 심볼로 이루어지며, 상기 할당된 공간 및 주파수 자원에 따라 전송되는 전송 심볼에 대해, 상기 공간 단위로 이산 푸리에 변환을 수행하는 단계; 및 상기 푸리에 변환 결과에 대해 주파수 필터 및 공간 필터를 적용하는 단계를 포함하며, 상기 주파수 필터 및 공간 필터를 적용하는 단계는 상기 공간 단위로, 상기 할당된 주파수 자원의 배치 위치에 따라 펄스 성형 필터를 선택하여, 상기 서브 심볼이 주파수 영역으로 푸리에 변환된 결과인 샘플에 대해 선택된 펄스 성형 필터를 적용하는 무선 통신 시스템에서 다중 접속 방법이 제공된다.According to an embodiment of the present invention to achieve the above object, the step of allocating resources for a plurality of user terminals, space and frequency; Performing discrete Fourier transform on the basis of a plurality of sub-symbols and performing transmission symbols transmitted according to the allocated spatial and frequency resources in units of spaces; And applying a frequency filter and a spatial filter to the Fourier transform result, wherein applying the frequency filter and the spatial filter comprises applying a pulse shaping filter to the spatial unit in accordance with an arrangement position of the allocated frequency resource. Optionally, a multiple access method is provided in a wireless communication system that applies a selected pulse shaping filter to a sample that is the result of Fourier transforming the sub-symbols into a frequency domain.
또한 상기한 목적을 달성하기 위해 본 발명의 다른 실시예에 따르면, 복수의 사용자 단말에 대한 자원을, 공간 및 주파수 별로 할당하는 단계; 복수의 서브 심볼로 이루어지며, 상기 할당된 공간 및 주파수 자원에 따라 전송되는 전송 심볼에 대해, 상기 공간 단위로 이산 푸리에 변환을 수행하는 단계; 및 상기 서브 심볼이 주파수 영역으로 푸리에 변환된 결과인 샘플에 대해 주파수 필터 및 공간 필터를 적용하는 단계를 포함하며, 상기 주파수 필터는 주파수 등화 필터 및 펄스 성형 필터를 포함하는 무선 통신 시스템에서 다중 접속 방법이 제공된다.In addition, according to another embodiment of the present invention to achieve the above object, the step of allocating resources for a plurality of user terminals, space and frequency; Performing discrete Fourier transform on the basis of a plurality of sub-symbols and performing transmission symbols transmitted according to the allocated spatial and frequency resources in units of spaces; And applying a frequency filter and a spatial filter to a sample resulting from the Fourier transform of the sub-symbols in the frequency domain, wherein the frequency filter comprises a frequency equalization filter and a pulse shaping filter. This is provided.
또한 상기한 목적을 달성하기 위해 본 발명의 또 다른 실시예에 따르면, 복수의 사용자 단말에 대한 자원을, 공간 및 주파수 별로 할당하는 자원 할당부; 복수의 서브 심볼로 이루어지며, 상기 할당된 공간 및 주파수 자원에 따라 전송되는 전송 심볼에 대해, 상기 공간 단위로 이산 푸리에 변환을 수행하는 푸리에 변환부; 및 상기 공간 단위로, 상기 할당된 주파수 자원의 배치 위치에 따라 펄스 성형 필터를 선택하여, 상기 서브 심볼이 주파수 영역으로 푸리에 변환된 결과인 샘플에 대해 선택된 펄스 성형 필터를 적용하는 필터링부를 포함하는 무선 통신 시스템에서 다중 접속을 위한 전송 장치가 제공된다.In addition, according to another embodiment of the present invention to achieve the above object, a resource allocator for allocating resources for a plurality of user terminals, space and frequency; A Fourier transform unit comprising a plurality of sub-symbols, and performing a discrete Fourier transform on the spatial units of the transmission symbols transmitted according to the allocated spatial and frequency resources; And a filtering unit for selecting a pulse shaping filter according to an arrangement position of the allocated frequency resource and applying the selected pulse shaping filter to a sample that is a result of Fourier transform of the sub-symbols in the frequency domain. A transmission apparatus for multiple access in a communication system is provided.
본 발명에 따르면, 고정된 펄스 성형 필터를 이용하지 않고, 주파수 별로 할당되는 자원의 배치 위치에 따라 펄스 성형 필터를 선택하여 사용함으로써, 서브캐리어간 간섭을 줄일 수 있다.According to the present invention, the interference between subcarriers can be reduced by selecting and using the pulse shaping filter according to the arrangement position of resources allocated for each frequency, without using a fixed pulse shaping filter.
또한 본 발명에 따르면, 샘플 단위로 주파수 필터 및 공간 필터를 적용함으로써, 높은 빔형성 해상도와 우수한 대역외 채널 성능을 제공할 수 있다.In addition, according to the present invention, by applying a frequency filter and a spatial filter on a sample basis, it is possible to provide high beamforming resolution and excellent out-of-band channel performance.
도 1 및 도 2는 GFDM을 설명하기 위한 도면이다.1 and 2 are diagrams for explaining the GFDM.
도 3은 본 발명의 일실시예에 따른 리소스 블록의 할당 맵을 나타내는 도면이다.3 is a diagram illustrating an allocation map of a resource block according to an embodiment of the present invention.
도 4 및 도 5는 도 3의 리소스 블록 할당 맵에 따른 필터링된 서브캐리어를 도시하는 도면이다. 4 and 5 are diagrams illustrating filtered subcarriers according to the resource block allocation map of FIG. 3.
도 6은 도 3의 리소스 블록 할당 맵에 따른 공간 다중화 접속을 설명하기 위한 도면이다.FIG. 6 is a diagram for describing spatial multiplexing access according to the resource block allocation map of FIG. 3.
도 7은 본 발명의 일실시예에 따른 전송 시스템을 설명하기 위한 도면이다. 7 is a view for explaining a transmission system according to an embodiment of the present invention.
도 8은 본 발명의 일실시예에 따른 수신 시스템을 설명하기 위한 도면이다.8 is a view for explaining a receiving system according to an embodiment of the present invention.
도 9는 본 발명의 일실시예에 따른 다중 접속을 위한 전송 장치를 설명하기 위한 도면이다.9 is a diagram illustrating a transmission device for multiple access according to an embodiment of the present invention.
도 10은 본 발명의 일실시예에 따른 다중 접속 방법을 설명하기 위한 도면이다.10 is a diagram illustrating a multiple access method according to an embodiment of the present invention.
도 11은 본 발명에 따른 쓰루풋과 GFDM 및 OFDM의 쓰루풋 시뮬레이션 결과를 도시하는 도면이다.11 is a diagram showing throughput and throughput simulation results of GFDM and OFDM according to the present invention.
도 12는 본 발명의 다른 실시예에 따른 다중 접속 방법을 설명하기 위한 의사 코드(pseudo-code)를 나타내는 도면이다.12 is a diagram illustrating a pseudo-code for explaining a multiple access method according to another embodiment of the present invention.
본 발명은 다양한 변경을 가할 수 있고 여러 가지 실시예를 가질 수 있는 바, 특정 실시예들을 도면에 예시하고 상세한 설명에 상세하게 설명하고자 한다. 그러나, 이는 본 발명을 특정한 실시 형태에 대해 한정하려는 것이 아니며, 본 발명의 사상 및 기술 범위에 포함되는 모든 변경, 균등물 내지 대체물을 포함하는 것으로 이해되어야 한다. 각 도면을 설명하면서 유사한 참조부호를 유사한 구성요소에 대해 사용하였다. As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements.
본 발명은 무선 통신 시스템에서 새로운 방식의 다중 접속 방법을 제안하며, 본 명세서에서는 본 발명에 따른 다중 접속 방법을 USFDMA(Universal Spatio-Frequency Division Multiple Access)로 명명하기로 한다.The present invention proposes a new method of multiple access in a wireless communication system. In the present specification, the multiple access method according to the present invention will be referred to as Universal Spatio-Frequency Division Multiple Access (USFDMA).
본 발명에 따른 다중 접속 방법은 초저지연, 고신뢰 및 고용량의 서비스 요구 조건에서 높은 빔형성 해상도와 좋은 대역외 채널 성능을 제공하며, GFDM과 OFDM 대비 높은 주파수 효율을 나타낸다.The multiple access method according to the present invention provides high beamforming resolution and good out-of-band channel performance under ultra low delay, high reliability, and high capacity service requirements, and exhibits higher frequency efficiency than GFDM and OFDM.
이하에서, 먼저 GFDM에 대해 간단히 살펴본 후, 본 발명에 따른 실시예들을 첨부된 도면을 참조하여 상세하게 설명한다.Hereinafter, after briefly reviewing the GFDM, embodiments according to the present invention will be described in detail with reference to the accompanying drawings.
도 1 및 도 2는 GFDM을 설명하기 위한 도면이다.1 and 2 are diagrams for explaining the GFDM.
GFDM은 N=KM개의 데이터를 전송할 때, 도 1에 도시된 바와 같이, K개의 서브캐리어(subcarrier)와 M개의 서브심볼(subsymbol)로 이루어진 데이터 블록의 형태로 데이터를 전송한다. 도 2에 도시된 OFDM의 데이터 블록과 비교하여, 도 1에 도시된 GFDM의 데이터 블록은 하나의 전송심볼이 복수의 서브심볼로 구성되며, GFDM에서는 하나의 서브캐리어가 복수의 서브심볼을 전송하는 형태이다.When GFDM transmits N = KM data, the GFDM transmits data in the form of a data block including K subcarriers and M subsymbols, as shown in FIG. 1. Compared to the OFDM data block shown in FIG. 2, the data block of the GFDM shown in FIG. 1 includes one transmission symbol composed of a plurality of subsymbols, and one subcarrier transmits a plurality of subsymbols in the GFDM. Form.
GFDM에서 보내고자 하는 모든 데이터는 GFDM 송신 행렬 A로 변조된 후 OFDM과 같이 채널의 지연 확산에 의한 영향을 최소화하고 GFDM의 블록간 간섭을 제거하기 위해 CP(Cyclic Prefix)를 덧붙여 전송한다.All data to be sent in the GFDM is modulated by the GFDM transmission matrix A and then added with a Cyclic Prefix (CP) to minimize the effect of delay spread of the channel and remove the inter-block interference of the GFDM, such as OFDM.
전송하고자 하는 데이터가 N=KM으로 일정할 때, 서브심볼의 개수가 증가하면, 서브캐리어의 간격이 증가한다. 이 때, 채널이 주파수 선택적인 특성을 갖는다면 자기 간섭을 제거할 수 없어 GFDM의 성능이 감소한다. 하지만 GFDM의 FFT 크기를 기존의 사용하던 FFT 크기보다 M배 증가시키면, 기존과 동일한 부반송파 간격사이에 M개의 샘플이 포함될 수 있어 주파수 해상도가 증가하여 주파수 선택적인 채널에서도 성능이 크게 감소하지 않는다.When the data to be transmitted is constant as N = KM, if the number of subsymbols increases, the spacing of subcarriers increases. At this time, if the channel has a frequency selective characteristic, magnetic interference cannot be eliminated, and thus the performance of the GFDM is reduced. However, if the FFT size of GFDM is increased by M times than the existing FFT size, M samples can be included between the same subcarrier spacings, so that the frequency resolution is increased and performance is not significantly reduced even in a frequency selective channel.
GFDM은 주파수 영역에서 고정된 펄스 성형 필터를 이용하여, 서브심볼의 주파수 변환 결과인 샘플에 대해 필터링을 수행한다. 그리고 주파수 등화 필터링 및 공간 필터링은 전송 심볼 단위로 수행된다.The GFDM uses a pulse shaping filter fixed in the frequency domain to perform filtering on a sample that is a result of frequency conversion of a subsymbol. Frequency equalization filtering and spatial filtering are performed in units of transmission symbols.
GFDM에서 펄스 성형 필터링에 의해 발생한 비직교 파형은 서브캐리어의 간섭을 일으켜 BER을 증가시킨다.Non-orthogonal waveforms generated by pulse shaping filtering in GFDM cause subcarrier interference to increase BER.
이에 본 발명은 서브캐리어간 간섭을 줄여, 초저지연, 고신뢰 및 고용량의 서비스 요구 조건을 만족시킬 수 있는 다중 접속 방법을 제안한다. Accordingly, the present invention proposes a multiple access method capable of satisfying ultra low delay, high reliability, and high capacity service requirements by reducing interference between subcarriers.
본 발명에 따른 다중 접속 방법은 고정된 펄스 성형 필터를 이용하지 않고, 주파수 별로 할당되는 자원의 배치 위치에 따라 펄스 성형 필터를 선택하여 사용함으로써, 서브캐리어간 간섭을 줄일 수 있다.In the multiple access method according to the present invention, the interference between subcarriers can be reduced by selecting and using a pulse shaping filter according to an arrangement position of resources allocated for each frequency, without using a fixed pulse shaping filter.
또한 본 발명에 따른 다중 접속 방법은 샘플 단위로 주파수 필터 및 공간 필터를 적용함으로써, 높은 빔형성 해상도와 우수한 대역외 채널 성능을 제공할 수 있다.In addition, the multiple access method according to the present invention can provide high beamforming resolution and excellent out-of-band channel performance by applying a frequency filter and a spatial filter on a sample basis.
본 발명에 따른 다중 접속 방법은 다중 접속을 위한 전송 장치에서 수행될 수 있으며, 전송 장치는 기지국일 수 있다.The multiple access method according to the present invention may be performed in a transmission apparatus for multiple access, and the transmission apparatus may be a base station.
도 3은 본 발명의 일실시예에 따른 리소스 블록의 할당 맵을 나타내며, 도 4 및 도 5는 도 3의 리소스 블록 할당 맵에 따른 필터링된 서브캐리어를 도시하는 도면이다. 그리고 도 6은 도 3의 리소스 블록 할당 맵에 따른 공간 다중화 접속을 설명하기 위한 도면이다.3 illustrates an allocation map of a resource block according to an embodiment of the present invention, and FIGS. 4 and 5 illustrate filtered subcarriers according to the resource block allocation map of FIG. 3. 6 is a diagram for describing a spatial multiplexing connection according to the resource block allocation map of FIG. 3.
도 3에는 4개의 서브캐리어 및 4개의 서브스트림이 4개의 사용자 단말에 할당되는 경우가 일실시예로서 설명되나, 자원의 할당은 실시예에 따라서 다양하게 이루어질 수 있다.In FIG. 3, a case in which four subcarriers and four substreams are allocated to four user terminals is described as an embodiment. However, resource allocation may be variously performed according to an embodiment.
본 발명에 따른 기지국은 자원 상황, 채널 상태, 서비스 요구 조건등을 고려하여, 도 3에 도시된 바와 같이, 사용자 단말 별로 공간 및 주파수 자원을 할당한다. 서브캐리어는 주파수 자원에 대응되며 서브스트림(substream)은 공간 자원에 대응된다. The base station according to the present invention allocates spatial and frequency resources for each user terminal as shown in FIG. 3 in consideration of resource conditions, channel conditions, service requirements, and the like. The subcarrier corresponds to the frequency resource and the substream corresponds to the spatial resource.
예를 들어, 제1사용자 단말(user1)에 대한 데이터는 제1 내지 제3서브캐리어(301, 302, 303)를 통해 전송되며, 동시에 제1 및 제2서브스트림(311, 312)을 통해 전송된다. 그리고 제4사용자 단말(user4)에 대한 데이터는 제4서브캐리어(304)를 통해 전송되며, 동시에 제1 내지 제4서브스트림(311, 312, 313, 314)을 통해 전송된다.For example, data for the first user terminal user1 is transmitted through the first to third subcarriers 301, 302, and 303, and simultaneously through the first and second substreams 311 and 312. do. The data for the fourth user terminal user4 is transmitted through the fourth subcarrier 304 and simultaneously transmitted through the first to fourth substreams 311, 312, 313, and 314.
기지국은 할당된 자원에 따라 전송 심볼을 사용자 단말로 전송하는데, 전송 심볼은 복수의 서브 심볼로 이루어진다. 기지국은 공간 단위 즉, 서브스트림별로 이산 푸리에 변환을 수행하며, 푸리에 변환에 따라 서브 심볼은 주파수 영역에서 서로 다른 주파수 성분으로 표현된다. The base station transmits a transmission symbol to a user terminal according to the allocated resource, the transmission symbol is composed of a plurality of sub-symbols. The base station performs a discrete Fourier transform for each spatial unit, that is, for each substream, and the sub-symbols are represented by different frequency components in the frequency domain according to the Fourier transform.
기지국은, 공간 단위로, 할당된 주파수 자원의 배치 위치에 따라 펄스 성형 필터를 선택하여, 서브 심볼이 주파수 영역으로 푸리에 변환된 결과인 샘플에 대해 선택된 펄스 성형 필터를 적용한다. 이산 푸리에 변환은 M-point FFT(Fast Fourier Transform)으로서, 푸리에 변환 결과 서브심볼 별로 서로 다른 주파수 성분을 나타내며, M은 서브심볼 개수에 대응된다.The base station selects, in spatial units, the pulse shaping filter according to the placement position of the allocated frequency resource, and applies the selected pulse shaping filter to the sample resulting from Fourier transform of the sub-symbols into the frequency domain. The discrete Fourier transform is an M-point Fast Fourier Transform (FFT), which represents different frequency components for each subsymbol as a result of the Fourier transform, and M corresponds to the number of subsymbols.
서브스트림별로 필터링된 서브캐리어를 도시한 도 4를 참조하면, 4개의 펄스 성형 필터가 적용되었음을 알 수 있다. 도 4의 필터링된 서브캐리어는 동시에 필터링이 수행되는 하나의 샘플군에 대해 표현된 것으로서, 하나의 서브캐리어를 통해 복수의 서브 심볼이 전송되므로, 복수의 샘플군에 대해 각각 펄스 성형 필터링이 수행된다. Referring to FIG. 4 illustrating the subcarriers filtered for each substream, it can be seen that four pulse shaping filters are applied. The filtered subcarriers of FIG. 4 are expressed for one sample group in which filtering is performed at the same time. Since a plurality of sub symbols are transmitted through one subcarrier, pulse shaping filtering is performed on the plurality of sample groups, respectively. .
즉, 도 4의 필터링된 서브캐리어를 시간-공간-주파수 영역에서 표현한 도 5와 같이, 시간-공간-주파수 영역에서 서브심볼 각각은 시간 영역에서의 심볼 듀레이션(duration)에 대응되므로, 모든 서브캐리어에 대해 서브심볼 별로 주파수 영역에서 샘플이 생성되고, 샘플군 별로 펄스 성형 필터링이 수행된다.That is, as shown in FIG. 5 in which the filtered subcarrier of FIG. 4 is represented in the time-space-frequency domain, each subsymbol in the time-space-frequency domain corresponds to a symbol duration in the time domain. Samples are generated in the frequency domain for each subsymbol for, and pulse shaping filtering is performed for each sample group.
펄스 성형 필터는 SRRC(Square-Root Raised Cosine) 필터(440), 레프트 스퀴즈(left-squeezed) SRRC 필터(410), 라이트 스퀴즈(right-squeezed) SRRC 필터(430) 및 사각 필터(420) 중에서 선택되며, 동일한 사용자 단말에 대한 주파수 자원의 할당 인덱스가 연속되는지에 따라 펄스 성형 필터가 선택될 수 있다.The pulse shaping filter is selected from a Square-Root Raised Cosine (SRRC) filter 440, a left-squeezed SRRC filter 410, a right-squeezed SRRC filter 430, and a square filter 420. The pulse shaping filter may be selected depending on whether the allocation index of the frequency resources for the same user terminal is continuous.
도 4 및 도 5를 참조하면, SRRC 필터(440)의 주파수 응답은 사다리꼴 형상이며, 사각 필터(420)의 주파수 응답은 사각형 형상이다. 그리고 SRRC 필터(440)와 비교하여, 레프트 스퀴즈 SRRC 필터(410)의 주파수 응답은 우측이 사각형 형상이며, 라이트 스퀴즈 SRRC 필터(430)의 주파수 응답은 좌측이 사각형 형상이다.4 and 5, the frequency response of the SRRC filter 440 is trapezoidal, and the frequency response of the rectangular filter 420 is rectangular. In comparison with the SRRC filter 440, the frequency response of the left squeeze SRRC filter 410 has a rectangular shape on the right side, and the frequency response of the light squeeze SRRC filter 430 has a square shape on the left side.
기지국은, 동일한 사용자 단말에 대한 주파수 자원의 할당 인덱스가 연속된 경우, 레프트 스퀴즈 SRRC 필터 및 라이트 스퀴즈 SRRC 필터 순으로 샘플에 펄스 성형 필터링을 수행하며, 연속된 할당 인덱스의 개수가 3 이상인 경우, 레프트 스퀴즈 SRRC 필터 및 라이트 스퀴즈 SRRC 필터 사이에 적어도 하나 이상의 사각 필터를 배치하여 샘플에 펄스 성형 필터링을 수행할 수 있다. The base station performs pulse shaping filtering on the samples in the order of left squeeze SRRC filter and light squeeze SRRC filter when the allocation index of the frequency resource for the same user terminal is continuous, and when the number of consecutive allocation indexes is 3 or more, Pulse shaping filtering may be performed on the sample by placing at least one square filter between the squeeze SRRC filter and the light squeeze SRRC filter.
도 3에서 할당 인덱스는 제1서브캐리어에서 제4서브캐리어 순으로 할당될 수 있다. 도 3을 참조하면, 제1사용자 단말에 대한 주파수 자원 즉, 서브캐리어는 연속되어 할당되므로, 레프트 스퀴즈 SRRC 필터(410) 및 라이트 스퀴즈 SRRC 필터(430) 순으로 샘플에 적용되대, 3개의 서브캐리어가 연속되어 할당되므로, 레프트 스퀴즈 SRRC 필터(410) 및 라이트 스퀴즈 SRRC 필터(430) 사이에 사각 필터(420)가 배치된다. 만약, 제1사용자 단말에 대해 4개의 서브캐리어가 연속되어 할당되면, 레프트 스퀴즈 SRRC 필터 및 라이트 스퀴즈 SRRC 필터 사이이에 2개의 사각 필터가 배치될 수 있다.In FIG. 3, the allocation indexes may be allocated in order from the first subcarrier to the fourth subcarrier. Referring to FIG. 3, since the frequency resources for the first user terminal, that is, the subcarriers are sequentially allocated, are applied to the samples in the order of left squeeze SRRC filter 410 and light squeeze SRRC filter 430, three subcarriers are applied. Since are allocated consecutively, the square filter 420 is disposed between the left squeeze SRRC filter 410 and the light squeeze SRRC filter 430. If four subcarriers are sequentially allocated to the first user terminal, two rectangular filters may be disposed between the left squeeze SRRC filter and the right squeeze SRRC filter.
그리고 제3사용자 단말에 대해서는 2개의 서브캐리어가 연속으로 할당되므로, 사각 필터(420)없이 레프트 스퀴즈 SRRC 필터(410) 및 라이트 스퀴즈 SRRC 필터(430)가 순서대로 샘플에 적용된다.Since two subcarriers are sequentially allocated to the third user terminal, the left squeeze SRRC filter 410 and the light squeeze SRRC filter 430 are sequentially applied to the sample without the quadrangle filter 420.
동일한 사용자 단말에 대한 주파수 자원의 할당 인덱스가 연속되지 않는 경우에, 기지국은 SRRC 필터를 이용하여 샘플에 펄스 성형 필터링을 수행한다. 도 3에서, 제4사용자 단말에 대한 서브캐리어는 서브스트림별로 하나만 할당되고 연속되지 않으므로, 제4사용자 단말에 대해서는 도 4와 같이 SRRC 필터(440)가 적용된다.If the allocation index of frequency resources for the same user terminal is not continuous, the base station performs pulse shaping filtering on the sample using the SRRC filter. In FIG. 3, since only one subcarrier for the fourth user terminal is allocated for each substream and is not continuous, the SRRC filter 440 is applied to the fourth user terminal as shown in FIG. 4.
이와 같이, 주파수 영역에서 필터링된 신호는 도 6에 도시된 바와 같이, 서로 다른 서브스트림을 통해 사용자 단말로 전송된다. 도 6(a) 내지 도 6(b)는 각각 제1 내지 제4서브캐리어 각각을 통해 전송되는 제1 내지 제4서브스트림을 나타낸다.As such, the filtered signal in the frequency domain is transmitted to the user terminal through different substreams, as shown in FIG. 6. 6 (a) to 6 (b) show first to fourth substreams transmitted through the first to fourth subcarriers, respectively.
제1서브캐리어가 할당된 제1 및 제2사용자 단말에 대한 심볼들은 도 6(a)와 같이, 제1 내지 제4서브스트림을 통해 제1 및 제2사용자 단말로 전송된다. 도 3을 참조하면, 제1사용자 단말에 대한 심볼들은 각각 서로 다른 빔으로 형성되는 제1 및 제2서브스트림을 통해 전송되며, 제2사용자 단말에 대한 심볼들은 각각 서로 다른 빔으로 형성되는 제3 및 제4서브스트림을 통해 전송된다.Symbols for the first and second user terminals to which the first subcarrier is allocated are transmitted to the first and second user terminals through the first to fourth substreams as shown in FIG. Referring to FIG. 3, symbols for a first user terminal are transmitted through first and second substreams each having different beams, and symbols for the second user terminal are each formed with different beams. And a fourth substream.
마찬가지로 각각의 서브캐리어가 할당된 심볼들은, 도 6(b) 내지 도 6(d)에 도시된 바와 같이, 제1 내지 제4서브스트림을 통해 사용자 단말로 전송된다.Likewise, the symbols to which each subcarrier is allocated are transmitted to the user terminal through the first to fourth substreams, as shown in FIGS. 6 (b) to 6 (d).
한편, 기지국은, 필터 성형 필터링을 수행하며, 주파수 등화 필터링 및 공간 필터링을 함께 수행할 수 있다. 주파수 등화 필터링 및 공간 필터링 역시 샘플 단위로 수행되며, 주파수 등화 필터 및 공간 필터는 사용자 단말 각각에 대한 채널 상태에 따라 결정될 수 있다.Meanwhile, the base station performs filter shaping filtering, and may perform frequency equalization filtering and spatial filtering together. Frequency equalization filtering and spatial filtering are also performed on a sample basis, and the frequency equalization filter and the spatial filter may be determined according to channel conditions for each user terminal.
도 7은 본 발명의 일실시예에 따른 전송 시스템을 설명하기 위한 도면이며, 도 8은 본 발명의 일실시예에 따른 수신 시스템을 설명하기 위한 도면이다.7 is a view for explaining a transmission system according to an embodiment of the present invention, Figure 8 is a view for explaining a reception system according to an embodiment of the present invention.
도 7은 기지국에서 수행되는 일련의 전송 처리 절차를 도시하며, 도 7에서는 도 3과 같이 리소스 블록이 할당되는 경우가 일실시예로서 설명된다. 도 8은 사용자 단말에서 수행되는 일련의 수신 처리 절차가 도시되며, 도 8에서는 제1사용자 단말에 대한 수신 시스템이 일실시예로서 설명된다.FIG. 7 illustrates a series of transmission processing procedures performed at a base station. In FIG. 7, a case in which resource blocks are allocated as shown in FIG. 3 will be described as an embodiment. 8 illustrates a series of reception processing procedures performed in a user terminal, and in FIG. 8, a reception system for a first user terminal is described as an embodiment.
본 발명에 따른 기지국은 도 3과 같이, 할당된 자원에 따라 데이터 블록을 배치(710)한다. 즉, 사용자 단말별로 할당된 서브캐리어 및 서브스트림에 따라 M개의 서브 심볼로 이루어진 데이터 블록이 배치된다. 데이터 블록은 전술된 전송 심볼에 대응된다.The base station according to the present invention arranges the data block according to the allocated resource as shown in FIG. 3 (710). That is, data blocks consisting of M sub-symbols are arranged according to subcarriers and substreams allocated for each user terminal. The data block corresponds to the above-described transmission symbol.
각 블록에 할당된 서브 심볼은 일실시예로서 QAM 데이터일 수 있으며, [수학식 1]과 같이 벡터로 표현될 수 있다. 또는 실시예에 따라서 서브 심볼별로 서로 다른 변조 방식이 적용될 수 있으며, 서브 심볼 각각은 적어도 하나 이상의 변조 방식에 따른 데이터일 수 있다.The sub-symbol allocated to each block may be QAM data as an embodiment, and may be represented by a vector as shown in [Equation 1]. Alternatively, different modulation schemes may be applied for each subsymbol according to an embodiment, and each subsymbol may be data according to at least one modulation scheme.
여기서, u는 데이터 블록의 인덱스, k는 서브캐리어의 인덱스, l은 서브스트림의 인덱스를 나타내며, 예를 들어, 데이터블록(711)에 대한 u는 4, k는 4, l은 1일 수 있다.Here, u represents the index of the data block, k represents the index of the subcarrier, and l represents the index of the substream. For example, u for the data block 711 may be 4, k may be 4, and l may be 1. .
기지국은 공간 단위로, 즉 서브스트림 단위로 M-point FFT를 수행(720)한다. 그리고 푸리에 변환 결과를 하나의 서브스트림에 대해 서브캐리어 인덱스별로 배치하며, 공간 단위로 수행된 푸리에 변환 결과를 서브스트림 인덱스 별로 배치(730)한다.The base station performs 720 an M-point FFT in units of space, that is, in units of substreams. The Fourier transform result is arranged for each subcarrier index for one substream, and the Fourier transform result for each substream is arranged for each substream index (730).
M-point FFT 결과, 데이터 블록별로 주파수 도메인 신호가 생성되며, 주파수 도메인 신호는 [수학식 2]와 같이 표현될 수 있다. As a result of the M-point FFT, a frequency domain signal is generated for each data block, and the frequency domain signal may be expressed as shown in [Equation 2].
여기서, i는 사용자 단말에 대한 인덱스를 나타내며, 은 M-point DFT 매트릭스를 나타낸다. 은 사이즈의 단위 행렬(identity matrix)의 l번째 컬럼을 나타내며, 이다. 는 크로네커 곱(Kronecker product) 연산자를 나타낸다.Here, i represents an index for the user terminal, Represents the M-point DFT matrix. silver Represents the l-th column of the identity matrix of size, to be. Denotes the Kronecker product operator.
기지국은 각 서브스트림별 주파수 도메인 신호에 대해 유효 채널(effective channel)의 감쇠(attenuation)를 보상하기 위한 전력 할당 파리미터(Q)를 곱하고(740), 서브 심볼이 주파수 영역으로 푸리에 변환된 결과인 샘플에 대해 필터링을 수행(750)한다. 전력 할당 파라미터(Q)는 도 12에서 보다 상세히 설명된다.The base station multiplies (740) a power allocation parameter (Q) for compensating for the attenuation of the effective channel for the frequency domain signal for each substream, and the sample is the result of Fourier transforming the sub-symbols into the frequency domain. Filtering is performed (750). The power allocation parameter Q is described in more detail in FIG. 12.
보다 구체적으로 기지국은 주파수 필터(frequecy filter, ) 및 공간 필터(spatial filter, )를 이용하여 샘플 단위로 필터링을 수행하는데, 주파수 필터는 주파수 등화 필터(frequecy domain equalizer, ) 및 펄스 성형 필터(pulse shaping filter, )를 포함한다.More specifically, the base station is a frequency filter (frequecy filter, ) And spatial filters, Filtering is performed on a per-sample basis. The frequency filter is a frequency domain equalizer (frequecy domain equalizer, ) And pulse shaping filter ).
기지국은 공간 단위로, 사용자 단말에 할당된 주파수 자원의 배치 위치, 즉 서브캐리어의 할당 인덱스에 따라 펄스 성형 필터를 선택하며, 전술된 4개의 필터 중 하나를 선택할 수 있다. 그리고 선택된 필터를 이용하여 서브스트림 단위로 샘플에 대해 펄스 성형 필터링을 수행한다.The base station selects a pulse shaping filter according to an arrangement position of frequency resources allocated to a user terminal, that is, an allocation index of a subcarrier, in space units, and may select one of the four filters described above. Pulse shaping filtering is performed on the samples in units of substreams using the selected filter.
이 때, 기지국은 펄스 성형 필터링과 함께 주파수 등화 필터링 및 펄스 성형 필터링을 함께 샘플 단위로 수행할 수 있다. 기지국은 사용자 단말 사이의 채널 상태에 따라 주파수 등화 필터 및 공간 필터를 결정하며, 서브심볼의 듀레이션별로 채널 상태를 고려하여 주파수 등화 필터 및 공간 필터를 결정할 수 있다. 특히, 기지국은 서브스트림별 채널 상태를 추가적으로 고려하여 공간 필터를 결정할 수 있으며, 공간 필터는 프리코딩(precoding)을 위한 필터로서 빔 형성을 위한 필터이다. In this case, the base station may perform frequency equalization filtering and pulse shaping filtering together with the pulse shaping filtering on a sample basis. The base station determines the frequency equalization filter and the spatial filter according to the channel state between user terminals, and may determine the frequency equalization filter and the spatial filter in consideration of the channel state for each duration of the subsymbol. In particular, the base station may determine the spatial filter in consideration of the channel status for each substream, and the spatial filter is a filter for beamforming as a filter for precoding.
이후 기지국은, MK-point IFFT를 수행하여 주파수 영역에서의 신호를 시간 영역에서의 신호로 변환(760)하고, 채널 상태에 따라 CP 또는 CS(Cyclic Suffix) 삽입하여, 사용자 단말로 전송(770)한다.Thereafter, the base station performs an MK-point IFFT to convert a signal in the frequency domain into a signal in the time domain (760), inserts a CP or CS (Cyclic Suffix) according to the channel state, and transmits the signal to the user terminal (770). do.
시간 영역에서의 신호는 [수학식 3]을 이용하여 얻어질 수 있다.The signal in the time domain can be obtained using [Equation 3].
여기서, 는 아다마르 곱(Hadamard product) 연산자를 나타내며, 는 IDFT 매트릭스를 나타낸다. NUE는 사용자 단말의 개수이며, 는 전력 할당 파라미터를 나타낸다.here, Represents the Hadamard product operator, Represents an IDFT matrix. N UE is the number of user terminals, Denotes a power allocation parameter.
즉, 주파수 도메인에서 모든 샘플(MK)에 대해 주파수 필터 백터와 공간 필터 백터를 곱합으로써, 필터링이 수행될 수 있다.That is, filtering may be performed by multiplying the frequency filter vector and the spatial filter vector for all samples MK in the frequency domain.
한편, IFFT와 CP 또는 CS 삽입은 GFDM과 동일하게 수행될 수 있으므로 자세한 설명은 생략하기로 한다.Meanwhile, since IFFT and CP or CS insertion may be performed in the same manner as GFDM, a detailed description thereof will be omitted.
이와 같이 시간 영역으로 변환된 신호는 사용자 단말로 전송되며, 사용자 단말은 도 8과 같이 수신된 신호로부터 QAM 데이터 심볼을 복원할 수 있다. 수신 신호의 처리 과정은, 송신 신호의 처리 과정의 역순으로 진행된다.As such, the signal converted into the time domain is transmitted to the user terminal, and the user terminal may recover the QAM data symbol from the received signal as shown in FIG. 8. The processing of the received signal proceeds in the reverse order of the processing of the transmission signal.
제1사용자 단말에 대한 수신 신호의 처리 절차를 나타내는 도 8을 참조하면, 먼저 제1사용자 단말은 수신된 신호(Yu)에서 CP 또는 CS를 제거(810)한다. 그리고 MK-point FFT를 수행(820)한 후, 주파수 영역에서 주파수 필터() 및 공간 필터()를 적용하여, 주파수 도메인 신호를 복조(830)한다. 그리고 M-point IFFT를 수행하여 시간 영역에서 QAM 데이터 심볼을 복원(840)한다.Referring to FIG. 8, which illustrates a procedure for processing a received signal for a first user terminal, first, a first user terminal removes 810 a CP or a CS from a received signal Y u . After performing the MK-point FFT (820), the frequency filter in the frequency domain ( ) And spatial filter ( ) Demodulates the frequency domain signal (830). The M-point IFFT is performed to restore the QAM data symbols in the time domain (840).
주파수 필터는 펄스 성형 필터() 및 주파수 등화 필터()를 포함하며, 필터링 과정은 송신 신호의 처리 과정과 동일하다.Frequency filter is pulse shaping filter ( ) And frequency equalization filter ( The filtering process is the same as that of the transmission signal.
도 9는 본 발명의 일실시예에 따른 다중 접속을 위한 전송 장치를 설명하기 위한 도면이다.9 is a diagram illustrating a transmission device for multiple access according to an embodiment of the present invention.
본 발명에 따른 전송 장치는 자원 할당부(910), 푸리에 변환부(920) 및 필터링부(930)를 포함한다.The transmission apparatus according to the present invention includes a resource allocator 910, a Fourier transform unit 920, and a filtering unit 930.
자원 할당부(910)는 복수의 사용자 단말에 대한 자원을, 공간 및 주파수 별로 할당하며, 일실시예로서, 도 3과 같이 할당할 수 있다.The resource allocator 910 allocates resources for a plurality of user terminals by space and frequency, and may allocate them as shown in FIG. 3 as an embodiment.
푸리에 변환부(920)는 복수의 서브 심볼로 이루어지며, 할당된 공간 및 주파수 자원에 따라 전송되는 전송 심볼에 대해, 공간 단위로 이산 푸리에 변환을 수행한다. The Fourier transform unit 920 is composed of a plurality of sub-symbols and performs discrete Fourier transform on a space unit with respect to transmission symbols transmitted according to the allocated space and frequency resources.
필터링부(930)는 공간 단위, 즉 서브스트림 단위로, 할당된 주파수 자원의 배치 위치에 따라 펄스 성형 필터를 선택하여, 서브 심볼이 주파수 영역으로 푸리에 변환된 결과인 샘플에 대해 선택된 펄스 성형 필터를 적용한다.The filtering unit 930 selects a pulse shaping filter according to an arrangement position of allocated frequency resources in spatial units, i.e., in a substream unit, and selects a pulse shaping filter selected for a sample that is a result of Fourier transform of a sub-symbol into a frequency domain. Apply.
필터링부(930)는 각 샘플에 대해 프리코딩을 수행하며, 실시예에 따라서, 주파수 필터링부 및 공간 필터링부를 포함할 수 있다. The filtering unit 930 performs precoding on each sample, and according to an embodiment, may include a frequency filtering unit and a spatial filtering unit.
주파수 필터링부는 펄스 성형 필터와 주파수 등화 필터를 이용하여, 샘플에 대해 필터링을 수행한다. 주파수 영역에서 각 샘플과 펄스 성형 필터의 주파수 응답, 주파수 등화 필터의 주파수 응답을 곱함으로써, 필터링이 수행될 수 있다. 그리고, 공간 필터링부 역시 샘플 단위로 필터링을 수행한다. The frequency filter performs filtering on the sample using a pulse shaping filter and a frequency equalization filter. Filtering may be performed by multiplying the frequency response of each sample and the pulse shaping filter, the frequency response of the frequency equalization filter in the frequency domain. The spatial filter also performs filtering on a sample basis.
필터링부(930)에 의해 프리코딩된 샘플들은 시간 영역의 신호로 변환된 후 사용자 단말로 전송된다.The samples precoded by the filtering unit 930 are converted into signals in the time domain and then transmitted to the user terminal.
펄스 성형 필터링은 도 3 내지 7에서 설명된 바와 같이 수행될 수 있다. Pulse shaping filtering may be performed as described in FIGS. 3 to 7.
한편, 본 발명에 따른 전송 장치는 전송 심볼 단위로 주파수 등화 필터링 및 공간 필터링을 수행하는 GFDM과 비교하여 샘플 단위로 주파수 등화 필터링 및 공간 필터링을 수행하는 것에 특징이 있는 발명으로서, 주파수 등화 필터링 및 공간 필터링에 대한 자세한 설명은 생략하기로 한다.Meanwhile, the transmission apparatus according to the present invention is characterized in that frequency equalization filtering and spatial filtering are performed on a sample basis as compared with GFDM which performs frequency equalization filtering and spatial filtering on a transmission symbol basis. Detailed description of the filtering will be omitted.
도 10은 본 발명의 일실시예에 따른 다중 접속 방법을 설명하기 위한 도면으로서, 도 10에서는 전술된 전송 장치의 다중 접속 방법이 일실시예로서 설명된다.FIG. 10 is a diagram illustrating a multiple access method according to an embodiment of the present invention. In FIG. 10, the multiple access method of the above-described transmission apparatus is described as an embodiment.
본 발명에 따른 전송 장치는 복수의 사용자 단말에 대한 자원을, 공간 및 주파수 별로 할당(S1010)한다. 그리고 복수의 서브 심볼로 이루어지며, 할당된 공간 및 주파수 자원에 따라 전송되는 전송 심볼에 대해, 공간 단위로 이산 푸리에 변환을 수행(S1020)한다. 여기서, 이산 푸리에 변환은 M-point FFT이며, M은 서브 심볼의 개수에 대응된다. 그리고 서브 심볼 별로 변조 방식이 결정되며, 서브 심볼은, 예를 들어, QAM 데이터 심볼일 수 있다.The transmission apparatus according to the present invention allocates resources for a plurality of user terminals by space and frequency (S1010). In operation S1020, a Discrete Fourier Transform is performed for each transmission symbol that is composed of a plurality of sub-symbols and is transmitted according to the allocated spatial and frequency resources. Here, the discrete Fourier transform is an M-point FFT, where M corresponds to the number of sub-symbols. The modulation scheme is determined for each sub symbol, and the sub symbol may be, for example, a QAM data symbol.
이후 전송 장치는 푸리에 변환 결과에 대해 주파수 필터 및 공간 필터를 적용하며, 서브 심볼이 주파수 영역으로 푸리에 변환된 결과인 샘플에 대해 주파수 필터 및 공간 필터를 적용할 수 있다. 주파수 필터는 펄스 성형 필터 및 주파수 등화 필터를 포함한다.Thereafter, the transmitting device may apply a frequency filter and a spatial filter to the Fourier transform result, and apply the frequency filter and the spatial filter to the sample that is the result of the Fourier transform of the sub-symbol into the frequency domain. The frequency filter includes a pulse shaping filter and a frequency equalization filter.
보다 구체적으로, 전송 장치는 공간 단위로, 할당된 주파수 자원의 배치 위치에 따라 펄스 성형 필터를 선택하여, 서브 심볼이 주파수 영역으로 푸리에 변환된 결과인 샘플에 대해 선택된 펄스 성형 필터를 적용(S1030)한다. 전송 장치는 SRRC 필터, 레프트 스퀴즈 SRRC 필터, 라이트 스퀴즈 SRRC 필터 및 사각 필터 중에서 펄스 성형 필터를 선택할 수 있다.More specifically, the transmitting apparatus selects a pulse shaping filter according to the arrangement position of the allocated frequency resource in units of space, and applies the selected pulse shaping filter to the sample resulting from Fourier transform of the sub-symbols in the frequency domain (S1030). do. The transmission device may select a pulse shaping filter from an SRRC filter, a left squeeze SRRC filter, a light squeeze SRRC filter, and a square filter.
그리고 전송 장치는 사용자 단말에 대한 채널 상태에 따른 주파수 등화 필터 및 공간 필터를 샘플에 적용할 수 있다.이 때, 전송 심볼에 대한 전력이 최소가 되도록 변조 지수 및 공간 필터가 동시에 결정될 수 있다.The transmitting device may apply the frequency equalization filter and the spatial filter according to the channel state of the user terminal to the sample. In this case, the modulation index and the spatial filter may be simultaneously determined so that the power for the transmission symbol is minimized.
한편, 본 발명에 따른 전송 장치는 전송 전력이 최소화할 수 있도록 주파수, 공간 필터 및 변조 지수를 결정할 수 있는데, 이는 도 12에서 상세히 설명하기로 한다.Meanwhile, the transmission apparatus according to the present invention may determine the frequency, the spatial filter and the modulation index to minimize the transmission power, which will be described in detail with reference to FIG. 12.
도 11은 본 발명에 따른 쓰루풋과 GFDM 및 OFDM의 쓰루풋 시뮬레이션 결과를 도시하는 도면이다.11 is a diagram showing throughput and throughput simulation results of GFDM and OFDM according to the present invention.
도 11은, 각 사용자는 하나의 기지국으로부터 동일 거리 감쇄를 갖는 레일리 페이딩 채널 환경에 속해 있는 것으로 가정하였고, 고이동성 (500km/s)과 저이동성(0km/s)을 갖는 사용자로 절반씩 나뉘며, 도플러 페이딩을 방지하기 위해 USFDMA와 GFDM의 경우 이동성에 따라 심볼 길이가 다른 웨이브폼을 공존시킨 조건에서의 시뮬레이션 결과를 도시한다. 길이가 서로 다른 OFDM 심볼은 낮은 대역외 채널(out of band, OOB) 성능으로 공존이 불가능하므로 긴 심볼(OFDM Long)과 짧은 심볼(OFDM Short)로 나누어 실험하였다. 시뮬레이션에서 중심 주파수는 5Ghz, 대역폭은 80MHz, 부반송파간 간격은 16.875KHz이며, 길이가 긴 심볼은 8192 FFT 크기를 사용하였고 짧은 심볼은 1024 FFT 크기를 사용하였다. FIG. 11 assumes that each user belongs to a Rayleigh fading channel environment having the same distance attenuation from one base station, and is divided in half into users having high mobility (500 km / s) and low mobility (0 km / s). In order to prevent Doppler fading, a simulation result in a condition in which USFDMA and GFDM coexist with waveforms having different symbol lengths according to mobility is shown. Since OFDM symbols of different lengths cannot coexist due to low out-of-band (OOB) performance, the experiments are divided into long symbols (OFDM Long) and short symbols (OFDM Short). In the simulation, the center frequency is 5Ghz, the bandwidth is 80MHz, and the interval between subcarriers is 16.875KHz. The long symbol uses 8192 FFT size and the short symbol uses 1024 FFT size.
OFDM과 GFDM은 심볼 레벨의 빔형성을, USFDMA은 샘플 레벨의 빔형성을 이용하기 때문에, USFDMA이 GFDM보다 빔형성 성능이 높으며 이동성에 맞는 웨이브폼 공존으로 OFDM 대비 주어진 조건 하에서 데이터 전송 용량 성능이 높음을 알 수 있다.Since OFDM and GFDM use symbol-level beamforming, and USFDMA uses sample-level beamforming, USFDMA has higher beamforming performance than GFDM, and data transfer capacity performance is higher under given conditions than OFDM due to mobility coexistence waveform coexistence. It can be seen.
도 12는 본 발명의 다른 실시예에 따른 다중 접속 방법을 설명하기 위한 의사 코드(pseudo-code)를 나타내는 도면이다.12 is a diagram illustrating a pseudo-code for explaining a multiple access method according to another embodiment of the present invention.
도 12에서는, 이동통신 서비스에서 요구되는 데이터 전송 용량 조건과 신뢰도 조건을 만족시키면서, 전송 심볼을 전송하는데 필요한 전력을 최소화하기 위한 방법이 설명된다. 본 발명은 데이터 전송 용량 조건과 신뢰도 조건을 만족시키면서 동시에 최소 전송 전력이 이용될 수 있도록 공간-주파수 필터() 및 변조 지수(modulation index)를 결정한다.In FIG. 12, a method for minimizing power required for transmitting a transmission symbol while satisfying a data transmission capacity condition and a reliability condition required for a mobile communication service is described. The present invention provides a space-frequency filter so that minimum transmission power can be used while satisfying data transmission capacity conditions and reliability conditions. ) And a modulation index.
공간-주파수 필터는 프리코더로서, 본 발명에 의해 결정된 공간-주파수 필터에 따라, 전송 심볼은 프리코딩되어 사용자 단말로 전송되며, 본 발명에 의해 결정된 변조 지수에 의해 주파수-공간 자원에 할당되는 비트수가 결정된다. 변조 지수는 심볼 당 얼마나 많은 비트를 담아낼 수 있는 정도를 나타내는 파라미터로서, 주파수-공간 자원(k, l)에 할당되는 비트수를 나타낸다(bit-loading).The space-frequency filter is a precoder, and according to the space-frequency filter determined by the present invention, the transmission symbols are precoded and transmitted to the user terminal, and bits allocated to frequency-spatial resources by the modulation index determined by the present invention. The number is determined. The modulation index is a parameter indicating how many bits can be stored per symbol and indicates the number of bits allocated to frequency-space resources (k, l).
본 발명에 따른 전송 장치는 먼저, 공간-주파수 자원마다 기 할당된 변조 지수에 따른 신뢰도 조건이 만족되며, 동시에 최소 송신 전력으로 데이터가 전송될 수 있도록 공간-주파수 필터를 결정하며, 일예로서, [수학식 4]와 같이 공간-주파수 필터를 결정할 수 있다. 여기서, 송신 전력(P)는 전술된 전력 할당 파라미터(Q)에 대응된다.The transmission apparatus according to the present invention first determines the space-frequency filter so that the reliability condition according to the modulation index pre-assigned for each space-frequency resource is satisfied, and at the same time, data can be transmitted with the minimum transmission power. As shown in Equation 4, a space-frequency filter may be determined. Here, the transmission power P corresponds to the power allocation parameter Q described above.
변조 지수에 따른 신뢰도 조건이 만족되는지 여부는 SINR을 이용하여 계산할 수 있다. 신뢰도 조건()보다 계산된 SINR()이 크면 신뢰도 조건을 만족한다고 판단할 수 있다. 변조 지수에 따라 전송되는 데이터가 결정되고, 사용자 단말과의 채널 상태에 따라 잡음이 결정될 수 있으므로, 신뢰도 조건과의 비교 대상인 SINR이 계산될 수 있다. 이 때, SINR은 공간-주파수 필터에 따라서도 결정되므로, 본 발명에 따른 전송 장치는 다양한 공간-주파수 필터에 대해 SINR 및 송신 전력을 계산하여, 신뢰도 조건을 만족하며 동시에 최소 전력을 이용할 수 있는 공간-주파수 필터를 결정할 수 있다.Whether the reliability condition according to the modulation index is satisfied may be calculated using SINR. Reliability conditions ( Calculated than SINR ( If) is large, it can be determined that the reliability condition is satisfied. Since the data to be transmitted is determined according to the modulation index, and the noise may be determined according to the channel state with the user terminal, the SINR to be compared with the reliability condition may be calculated. At this time, since the SINR is also determined according to the space-frequency filter, the transmission apparatus according to the present invention calculates the SINR and the transmission power for various space-frequency filters, satisfying the reliability conditions and simultaneously using the minimum power. The frequency filter can be determined.
송신 전력이 증가될수록 SINR이 높아질 수 있으므로, 신뢰도 조건을 만족하는 최소 송신 전력에 대응되는 공간-주파수 필터가 [수학식 4]의 해로 결정될 수 있다.Since the SINR may be increased as the transmission power is increased, a space-frequency filter corresponding to the minimum transmission power that satisfies the reliability condition may be determined as the solution of Equation 4.
도 7에서 채널 상태에 따라 공간-주파수 필터가 결정될 수 있다고 설명되었는데, 실시예에 따라서 전송 장치는 채널 상태를 고려함과 동시에 송신 전력을 최소화할 수 있는 공간-주파수 필터를 결정할 수 있다.In FIG. 7, it is described that the spatial-frequency filter may be determined according to the channel state. According to the embodiment, the transmitting device may determine the spatial-frequency filter capable of minimizing the transmission power while considering the channel state.
또한 본 발명에 따른 전송 장치는 공간-주파수 자원에 대한 공간-주파수 필터가 주어진 경우, 채널과 공간-주파수 필터의 결합에 따라 결정되는 유효 채널에서 사용자 단말 별 데이터 전송 용량 조건(bi)을 만족하는 동시에, 전송 심볼이 최소 전력으로 전송될 수 있도록 공간-주파수 자원 별로 변조 지수를 결정한다. In addition, transmitting device space according to the invention meet the user terminal by data transmission capacity conditions in the effective channel is determined by the combination of the frequency filter (b i) - space for frequency resource-frequency when the filter is given, channels, and spaces At the same time, the modulation index is determined for each space-frequency resource so that the transmission symbol can be transmitted with the minimum power.
본 발명에 따른 전송 장치는 일예로서, [수학식 5]와 같이, 공간-주파수 자원 별로 변조 지수를 결정할 수 있다.As an example, the transmission apparatus according to the present invention may determine a modulation index for each space-frequency resource, as shown in [Equation 5].
본 발명에 따른 전송 장치는 변조 지수를 초기값으로부터 1씩 증가시키면서 사용자 단말 별 데이터 전송 용량 조건을 만족하는지 판단할 수 있다. 변조 지수가 증가할수록 전송률이 증가하므로 데이터 전송 용량 조건이 만족될 가능성이 높아질 수 있다. The transmission apparatus according to the present invention may determine whether the data transmission capacity condition for each user terminal is satisfied while increasing the modulation index by one from the initial value. As the modulation index increases, the rate increases, which may increase the likelihood that the data transmission capacity condition is satisfied.
이 때, 전송 장치는 전술된 바와 같이, 결정된 공간-주파수 필터에 따른 유효 채널에서 데이터 전송 용량 조건이 만족할 수 있도록 변조 지수를 결정하며, 동시에 전송 심볼이 최소 전력으로 전송될 수 있도록 변조 지수를 결정한다.At this time, the transmission apparatus determines a modulation index such that the data transmission capacity condition is satisfied in the effective channel according to the determined space-frequency filter as described above, and simultaneously determines the modulation index so that the transmission symbol can be transmitted at the minimum power. do.
결국, 본 발명에 따른 전송 장치는 [수학식 4] 및 [수학식 5]를 동시에 만족하는 공간-주파수 필터 및 변조 지수를 결정할 수 있다.As a result, the transmission apparatus according to the present invention can determine the spatial-frequency filter and the modulation index satisfying the equations (4) and (5) at the same time.
다시 설명하면, 본 발명에 따른 전송 장치는 주파수 및 공간 자원에 대한 기 설정된 변조 지수를 이용하여, 전송 전력을 최소화하는 주파수 필터 및 공간 필터를 결정하며, 이와 같이 결정된 주파수 필터 및 공간 필터를 이용하여, 전송 전력을 최소화하는 변조 지수를 갱신할 수 있다. 그리고 갱신된 변조 지수는 다시 공간-주파수 필터를 결정하는데 이용될 수 있다.In other words, the transmission apparatus according to the present invention determines a frequency filter and a spatial filter that minimize transmission power by using a preset modulation index for frequency and spatial resources, and uses the frequency filter and spatial filter determined as described above. For example, the modulation index may be updated to minimize the transmission power. The updated modulation index can then be used to determine the space-frequency filter.
한편, 본 발명에 따르면, 샘플별로 주파수 필터 및 공간 필터가 적용되므로, 서브 심볼 각각에 대해 공간-주파수 필터 및 변조 지수가 다르게 결정될 수 있으며, 결국 서브 심볼 별로 서로 다른 송신 전력이 할당되어 전송될 수 있다.Meanwhile, according to the present invention, since the frequency filter and the spatial filter are applied for each sample, the spatial-frequency filter and the modulation index may be differently determined for each subsymbol, and thus different transmission powers may be allocated and transmitted for each subsymbol. have.
전술된 공간-주파수 필터 및 변조 지수를 결정하는 방법을 의사 코드로 표현하면 도 12와 같다.A method of determining the above-described spatial-frequency filter and modulation index is represented by a pseudo code as shown in FIG. 12.
앞서 설명한 기술적 내용들은 다양한 컴퓨터 수단을 통하여 수행될 수 있는 프로그램 명령 형태로 구현되어 컴퓨터 판독 가능 매체에 기록될 수 있다. 상기 컴퓨터 판독 가능 매체는 프로그램 명령, 데이터 파일, 데이터 구조 등을 단독으로 또는 조합하여 포함할 수 있다. 상기 매체에 기록되는 프로그램 명령은 실시예들을 위하여 특별히 설계되고 구성된 것들이거나 컴퓨터 소프트웨어 당업자에게 공지되어 사용 가능한 것일 수도 있다. 컴퓨터 판독 가능 기록 매체의 예에는 하드 디스크, 플로피 디스크 및 자기 테이프와 같은 자기 매체(magnetic media), CD-ROM, DVD와 같은 광기록 매체(optical media), 플롭티컬 디스크(floptical disk)와 같은 자기-광 매체(magneto-optical media), 및 롬(ROM), 램(RAM), 플래시 메모리 등과 같은 프로그램 명령을 저장하고 수행하도록 특별히 구성된 하드웨어 장치가 포함된다. 프로그램 명령의 예에는 컴파일러에 의해 만들어지는 것과 같은 기계어 코드뿐만 아니라 인터프리터 등을 사용해서 컴퓨터에 의해서 실행될 수 있는 고급 언어 코드를 포함한다. 하드웨어 장치는 실시예들의 동작을 수행하기 위해 하나 이상의 소프트웨어 모듈로서 작동하도록 구성될 수 있으며, 그 역도 마찬가지이다.The technical contents described above may be embodied in the form of program instructions that may be executed by various computer means and may be recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the embodiments, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, 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 not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.
이상과 같이 본 발명에서는 구체적인 구성 요소 등과 같은 특정 사항들과 한정된 실시예 및 도면에 의해 설명되었으나 이는 본 발명의 보다 전반적인 이해를 돕기 위해서 제공된 것일 뿐, 본 발명은 상기의 실시예에 한정되는 것은 아니며, 본 발명이 속하는 분야에서 통상적인 지식을 가진 자라면 이러한 기재로부터 다양한 수정 및 변형이 가능하다. 따라서, 본 발명의 사상은 설명된 실시예에 국한되어 정해져서는 아니되며, 후술하는 특허청구범위뿐 아니라 이 특허청구범위와 균등하거나 등가적 변형이 있는 모든 것들은 본 발명 사상의 범주에 속한다고 할 것이다.In the present invention as described above has been described by the specific embodiments, such as specific components and limited embodiments and drawings, but this is provided to help a more general understanding of the present invention, the present invention is not limited to the above embodiments. For those skilled in the art, various modifications and variations are possible from these descriptions. Therefore, the spirit of the present invention should not be limited to the described embodiments, and all the things that are equivalent to or equivalent to the claims as well as the following claims will belong to the scope of the present invention. .
Claims (16)
- 복수의 사용자 단말에 대한 자원을, 공간 및 주파수 별로 할당하는 단계;Allocating resources for a plurality of user terminals by space and frequency;복수의 서브 심볼로 이루어지며, 상기 할당된 공간 및 주파수 자원에 따라 전송되는 전송 심볼에 대해, 상기 공간 단위로 이산 푸리에 변환을 수행하는 단계; 및Performing discrete Fourier transform on the basis of a plurality of sub-symbols and performing transmission symbols transmitted according to the allocated spatial and frequency resources in units of spaces; And상기 푸리에 변환 결과에 대해 주파수 필터 및 공간 필터를 적용하는 단계를 포함하며,Applying a frequency filter and a spatial filter to the Fourier transform result;상기 주파수 필터 및 공간 필터를 적용하는 단계는Applying the frequency filter and the spatial filter상기 공간 단위로, 상기 할당된 주파수 자원의 배치 위치에 따라 펄스 성형 필터를 선택하여, 상기 서브 심볼이 주파수 영역으로 푸리에 변환된 결과인 샘플에 대해 선택된 펄스 성형 필터를 적용하는 Selecting the pulse shaping filter according to the arrangement position of the allocated frequency resource in the spatial unit, and applying the selected pulse shaping filter to a sample that is a result of Fourier transforming of the sub-symbols in the frequency domain무선 통신 시스템에서 다중 접속 방법.Multiple access method in wireless communication system.
- 제 1항에 있어서,The method of claim 1,상기 주파수 필터 및 공간 필터를 적용하는 단계는Applying the frequency filter and the spatial filterSRRC 필터, 레프트 스퀴즈(left-squeezed) SRRC 필터, 라이트 스퀴즈(right-squeezed) SRRC 필터 및 사각 필터 중에서 펄스 성형 필터를 선택하는Selecting pulse shaping filters from SRRC filters, left-squeezed SRRC filters, right-squeezed SRRC filters, and square filters무선 통신 시스템에서 다중 접속 방법.Multiple access method in wireless communication system.
- 제 2항에 있어서,The method of claim 2,상기 주파수 필터 및 공간 필터를 적용하는 단계는Applying the frequency filter and the spatial filter동일한 사용자 단말에 대한 주파수 자원의 할당 인덱스가 연속된 경우, 레프트 스퀴즈 SRRC 필터 및 라이트 스퀴즈 SRRC 필터 순으로 상기 샘플에 펄스 성형 필터링을 수행하는When the allocation index of frequency resources for the same user terminal is continuous, the pulse shaping filtering is performed on the samples in the order of left squeeze SRRC filter and light squeeze SRRC filter.무선 통신 시스템에서 다중 접속 방법.Multiple access method in wireless communication system.
- 제 3항에 있어서,The method of claim 3, wherein상기 주파수 필터 및 공간 필터를 적용하는 단계는Applying the frequency filter and the spatial filter상기 연속된 할당 인덱스의 개수가 3 이상인 경우, 상기 레프트 스퀴즈 SRRC 필터 및 라이트 스퀴즈 SRRC 필터 사이에 적어도 하나 이상의 사각 필터를 배치하여 상기 샘플에 펄스 성형 필터링을 수행하는When the number of consecutive allocation indices is 3 or more, at least one rectangular filter is disposed between the left squeeze SRRC filter and the light squeeze SRRC filter to perform pulse shaping filtering on the sample.무선 통신 시스템에서 다중 접속 방법.Multiple access method in wireless communication system.
- 제 2항에 있어서,The method of claim 2,상기 주파수 필터 및 공간 필터를 적용하는 단계는Applying the frequency filter and the spatial filter동일한 사용자 단말에 대한 주파수 자원의 할당 인덱스가 연속되지 않는 경우, 상기 SRRC 필터를 이용하여 상기 샘플에 펄스 성형 필터링을 수행하는When the allocation index of the frequency resource for the same user terminal is not continuous, performing pulse shaping filtering on the sample using the SRRC filter무선 통신 시스템에서 다중 접속 방법.Multiple access method in wireless communication system.
- 제 1항에 있어서,The method of claim 1,상기 주파수 필터 및 공간 필터를 적용하는 단계는Applying the frequency filter and the spatial filter상기 사용자 단말에 대한 채널 상태에 따른 주파수 등화 필터를 상기 샘플에 적용하는 단계; 및Applying a frequency equalization filter to the sample according to channel conditions for the user terminal; And상기 사용자 단말에 대한 채널 상태에 따른 공간 필터를 상기 샘플에 적용하는 단계Applying a spatial filter to the sample according to channel conditions for the user terminal를 포함하는 무선 통신 시스템에서 다중 접속 방법.Multiple access method in a wireless communication system comprising a.
- 제 1항에 있어서,The method of claim 1,상기 이산 푸리에 변환은The Discrete Fourier TransformM-point FFT이며,M-point FFT,상기 M은 상기 서브 심볼의 개수에 대응되는M corresponds to the number of sub-symbols무선 통신 시스템에서 다중 접속 방법.Multiple access method in wireless communication system.
- 제 1항에 있어서,The method of claim 1,상기 서브 심볼 별로 변조 방식이 결정되며,The modulation method is determined for each sub-symbol,상기 전송 심볼에 대한 전력이 최소가 되도록, 변조 지수 및 상기 공간 필터가 동시에 결정되는The modulation index and the spatial filter are determined simultaneously so that the power for the transmitted symbol is minimal무선 통신 시스템에서 다중 접속 방법.Multiple access method in wireless communication system.
- 제 8항에 있어서,The method of claim 8,상기 서브 심볼은The sub symbol isQAM 데이터인QAM data무선 통신 시스템에서 다중 접속 방법.Multiple access method in wireless communication system.
- 복수의 사용자 단말에 대한 자원을, 공간 및 주파수 별로 할당하는 단계;Allocating resources for a plurality of user terminals by space and frequency;복수의 서브 심볼로 이루어지며, 상기 할당된 공간 및 주파수 자원에 따라 전송되는 전송 심볼에 대해, 상기 공간 단위로 이산 푸리에 변환을 수행하는 단계; 및Performing discrete Fourier transform on the basis of a plurality of sub-symbols and performing transmission symbols transmitted according to the allocated spatial and frequency resources in units of spaces; And상기 서브 심볼이 주파수 영역으로 푸리에 변환된 결과인 샘플에 대해 주파수 필터 및 공간 필터를 적용하는 단계를 포함하며,Applying a frequency filter and a spatial filter to a sample resulting from the Fourier transform of the sub-symbols in the frequency domain,상기 주파수 필터는 주파수 등화 필터 및 펄스 성형 필터를 포함하는The frequency filter includes a frequency equalization filter and a pulse shaping filter.무선 통신 시스템에서 다중 접속 방법.Multiple access method in wireless communication system.
- 제 10항에 있어서,The method of claim 10,상기 주파수 필터 및 공간 필터를 적용하는 단계는Applying the frequency filter and the spatial filter상기 공간 단위로, 상기 할당된 주파수 자원의 배치 위치에 따라 펄스 성형 필터를 선택하여, 상기 샘플에 대해 선택된 펄스 성형 필터를 적용하는 단계;Selecting a pulse shaping filter according to the arrangement position of the allocated frequency resource, and applying the selected pulse shaping filter for the sample on the spatial basis;상기 사용자 단말에 대한 채널 상태에 따른 주파수 등화 필터를 상기 샘플에 적용하는 단계; 및Applying a frequency equalization filter to the sample according to channel conditions for the user terminal; And상기 사용자 단말에 대한 채널 상태에 따른 공간 필터를 상기 샘플에 적용하는 단계Applying a spatial filter to the sample according to channel conditions for the user terminal를 포함하는 무선 통신 시스템에서 다중 접속 방법.Multiple access method in a wireless communication system comprising a.
- 제 10항에 있어서,The method of claim 10,상기 주파수 및 공간 자원에 대한 기 설정된 변조 지수를 이용하여, 전송 전력을 최소화하는 상기 공간 필터를 결정하는 단계; 및Determining the spatial filter that minimizes transmission power by using a preset modulation index for the frequency and spatial resources; And상기 공간 필터를 이용하여, 상기 전송 전력을 최소화하는 상기 변조 지수를 갱신하는 단계Using the spatial filter, updating the modulation index to minimize the transmit power를 포함하는 무선 통신 시스템에서 다중 접속 방법.Multiple access method in a wireless communication system comprising a.
- 복수의 사용자 단말에 대한 자원을, 공간 및 주파수 별로 할당하는 자원 할당부;A resource allocator for allocating resources for a plurality of user terminals by space and frequency;복수의 서브 심볼로 이루어지며, 상기 할당된 공간 및 주파수 자원에 따라 전송되는 전송 심볼에 대해, 상기 공간 단위로 이산 푸리에 변환을 수행하는 푸리에 변환부; 및A Fourier transform unit comprising a plurality of sub-symbols, and performing a discrete Fourier transform on the spatial units of the transmission symbols transmitted according to the allocated spatial and frequency resources; And상기 공간 단위로, 상기 할당된 주파수 자원의 배치 위치에 따라 펄스 성형 필터를 선택하여, 상기 서브 심볼이 주파수 영역으로 푸리에 변환된 결과인 샘플에 대해 선택된 펄스 성형 필터를 적용하는 필터링부A filtering unit that selects a pulse shaping filter according to the arrangement position of the allocated frequency resources and applies the selected pulse shaping filter to a sample that is a result of Fourier transforming the sub-symbols in the frequency domain in the spatial unit를 포함하는 무선 통신 시스템에서 다중 접속을 위한 전송 장치.Transmission apparatus for multiple access in a wireless communication system comprising a.
- 제 13항에 있어서,The method of claim 13,상기 필터링부는The filtering unit상기 펄스 성형 필터와 주파수 등화 필터를 이용하여, 상기 샘플에 대해 필터링을 수행하는 주파수 필터링부; 및A frequency filter configured to perform filtering on the sample using the pulse shaping filter and the frequency equalization filter; And공간 필터를 이용하여, 상기 샘플에 대해 필터링을 수행하는 공간 필터링부A spatial filter for filtering the sample using a spatial filter를 포함하는 무선 통신 시스템에서 다중 접속을 위한 전송 장치.Transmission apparatus for multiple access in a wireless communication system comprising a.
- 제 13항에 있어서,The method of claim 13,상기 필터링부는The filtering unitSRRC 필터, 레프트 스퀴즈(left-squeezed) SRRC 필터, 라이트 스퀴즈(right-squeezed) SRRC 필터 및 사각 필터 중에서 펄스 성형 필터를 선택하는Selecting pulse shaping filters from SRRC filters, left-squeezed SRRC filters, right-squeezed SRRC filters, and square filters무선 통신 시스템에서 다중 접속을 위한 전송 장치.Transmission apparatus for multiple access in a wireless communication system.
- 제 15항에 있어서,The method of claim 15,상기 필터링부는The filtering unit동일한 사용자 단말에 대한 주파수 자원의 할당 인덱스가 연속된 경우, 레프트 스퀴즈 SRRC 필터 및 라이트 스퀴즈 SRRC 필터 순으로 상기 샘플에 펄스 성형 필터링을 수행하며,When the allocation index of the frequency resource for the same user terminal is continuous, pulse shaping filtering is performed on the samples in the order of left squeeze SRRC filter and light squeeze SRRC filter,상기 연속된 할당 인덱스의 개수가 3 이상인 경우, 상기 레프트 스퀴즈 SRRC 필터 및 라이트 스퀴즈 SRRC 필터 사이에 적어도 하나 이상의 사각 필터를 배치하여 상기 샘플에 펄스 성형 필터링을 수행하는When the number of consecutive allocation indices is 3 or more, at least one rectangular filter is disposed between the left squeeze SRRC filter and the light squeeze SRRC filter to perform pulse shaping filtering on the sample.무선 통신 시스템에서 다중 접속을 위한 전송 장치.Transmission apparatus for multiple access in a wireless communication system.
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