WO2016185749A1 - 装置、方法、及びプログラム - Google Patents
装置、方法、及びプログラム Download PDFInfo
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- WO2016185749A1 WO2016185749A1 PCT/JP2016/055287 JP2016055287W WO2016185749A1 WO 2016185749 A1 WO2016185749 A1 WO 2016185749A1 JP 2016055287 W JP2016055287 W JP 2016055287W WO 2016185749 A1 WO2016185749 A1 WO 2016185749A1
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- base station
- terminal device
- codebook
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L27/00—Modulated-carrier systems
- H04L27/26—Systems using multi-frequency codes
- H04L27/2601—Multicarrier modulation systems
- H04L27/2626—Arrangements specific to the transmitter only
- H04L27/2627—Modulators
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J13/00—Code division multiplex systems
- H04J13/16—Code allocation
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/0413—MIMO systems
- H04B7/0456—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04J—MULTIPLEX COMMUNICATION
- H04J13/00—Code division multiplex systems
- H04J13/16—Code allocation
- H04J2013/165—Joint allocation of code together with frequency or time
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
- H04W88/08—Access point devices
Definitions
- the present disclosure relates to an apparatus, a method, and a program.
- Patent Literature 1 discloses an example of a code word generation method using a SCAM code book and a design method of the code book.
- SCMA for each of a plurality of layers to be multiplexed, a codeword of the layer is generated from the data of the layer based on the codebook for the layer. Each signal element in the codewords of the plurality of layers is mapped over a plurality of radio resources. At this time, signal elements corresponding to each of the plurality of layers are multiplexed and transmitted non-orthogonally. With this configuration, the SCMA can further improve the frequency use efficiency.
- the base station can select a more suitable codebook in order to further improve frequency use efficiency by non-orthogonal multiplexing of signal elements corresponding to each of a plurality of layers.
- the present disclosure proposes an apparatus, a method, and a program that enable a base station to select a more suitable codebook.
- a communication unit that performs wireless communication, and a control unit that controls information about a code book for performing multidimensional modulation of input data into a codeword from the communication unit to a base station;
- a device comprising:
- an acquisition unit that acquires information about a code book for multi-dimensionally modulating input data into a code word from a terminal, and a selection unit that selects the code book after acquiring the information,
- a device comprising:
- the processor acquires information about a code book for multi-dimensionally modulating input data into a code word from a terminal, and selects the code book after acquiring the information. And a method is provided.
- the computer performs wireless communication, and controls the information about the code book for multi-dimensionally modulating the input data into the code word to be transmitted to the base station;
- a program is provided to execute
- the computer acquires information about a code book for multi-dimensionally modulating input data into a code word from a terminal, and selects the code book after acquiring the information. Are provided.
- an apparatus, a method, and a program that enable a base station to select a more suitable codebook are provided.
- FIG. 5 is an explanatory diagram for describing an example of a reference signal generation method according to the embodiment
- FIG. 5 is an explanatory diagram for describing an example of a reference signal generation method according to the embodiment
- FIG. 4 is an explanatory diagram for describing an example of a reference signal transmission method according to the embodiment
- FIG. 7 is an explanatory diagram for describing another example of the reference signal transmission method according to the embodiment
- FIG. 5 is an explanatory diagram for describing an example of a reference signal generation method according to the embodiment
- FIG. 4 is an explanatory diagram for describing an example of a reference signal transmission method according to the embodiment
- FIG. 7 is an explanatory diagram for describing another example of the reference signal transmission method according to the embodiment
- FIG. 1 is an explanatory diagram for explaining an example of a schematic process for SCMA.
- a code word x is generated from data (binary data) b after error correction encoding based on a code book.
- the code book is information indicating a correspondence between a data candidate and a code word
- the data b is converted one-to-one into a code word x corresponding to the data b in the code book.
- a codebook for each layer is prepared for layer separation.
- each signal element in the generated codeword is mapped to a corresponding radio resource.
- code words of a plurality of layers are multiplexed, and then each signal element in the multiplexed code word is mapped to a corresponding radio resource.
- each signal element in a layer codeword is mapped to a corresponding radio resource, and then two or more signal elements (ie, different) mapped to the same radio resource.
- Layer signal elements may be multiplexed.
- the signal element mapped to the radio resource is transmitted.
- SCMA is not an orthogonal access method like OFDMA, but a non-orthogonal access method.
- FIG. 2 is an explanatory diagram for explaining an example of generating a code word based on a code book.
- data candidates b i and codewords x j are shown.
- the size of the code book that is, the number of data candidates b i and the number of code words x j are each M.
- data that is input information is a vector including bits as elements, and has a length of log 2 M.
- the code word that is output information is a vector that includes a complex number as a signal element, and has the same length as the number K of radio resources used for transmitting the code word. Therefore, it can be said that the code book is a function whose input information and output information are vectors.
- the code word that is output information is required to satisfy a desired condition suitable for layer multiplexing.
- FIG. 3 is an explanatory diagram for explaining an example of a code book.
- codebooks 1 to 6 are shown.
- Codebooks 1 to 6 are codebooks for layers 1 to 6.
- the data as input information is 2-bit data
- the number of data candidates is four. Therefore, the number of code words in each code book is four.
- the codewords in each codebook two of the four signal elements (ie complex numbers) are zero and the two different codewords are sparse. Also, in the codeword within each codebook, two of the four signal elements are not zero. That is, the number N of non-zero signal elements among the four signal elements (in other words, a four-dimensional constellation) is 2.
- FIG. 4 is an explanatory diagram for explaining an example of resource mapping of a code book.
- six layers and four radio resources are shown.
- four radio resources are prepared.
- non-zero signal elements that is, two signal elements
- a four-dimensional constellation signal is divided and mapped into two two-dimensional constellations.
- the first signal element in the layer 1 codeword is mapped to the radio resource 1
- the second signal element in the layer 1 codeword is mapped to the radio resource 2.
- the first signal element in the layer 3 codeword is mapped to the radio resource 1
- the third signal element in the layer 3 codeword is mapped to the radio resource 3.
- the overload realized is 150%.
- the receiving apparatus refers to received signals of four radio resources and estimates an input vector that maximizes the posterior probability of the received signals.
- J layer codewords are mapped to K radio resources.
- the received signal yk in the kth radio resource is expressed as follows.
- h k is a channel characteristic in the k-th radio resource
- n k is a noise component added in the k-th radio resource.
- SIC Successive Interference Cancellation
- a receiving apparatus sequentially cancels reception signals of other layers as interference components in the process of demodulating a reception signal of a certain layer. By such processing, the received signal of the layer is separated, and the received signal of the desired layer is obtained.
- SCMA is expected to obtain good characteristics even when beam forming is not used during multi-user communication.
- SCMA Downlink Multiple Access of 5G Wireless Networks
- SCMA describes superiority in a multi-user environment by layer separation and multiplexing using codebooks.
- a MIMO (multiple-input and multiple-output) implementation method that realizes information related to precoding without feedback from a terminal device is called open-loop MIMO.
- the terminal device does not transmit a PMI (Precoder Matrix Indicator) for selecting a precoder. Therefore, in open-loop MIMO, it is possible to reduce the load related to uplink feedback, and an improvement in resistance to channel fluctuation is also expected.
- PMI Precoder Matrix Indicator
- open-loop MIMO is a useful method for terminal devices that move at high speed, and is still considered to be an important transmission mode in future cellular communications such as SCMA.
- TM3 transmission mode 3
- CQI Channel Quality Indicator
- RI Rank Indicator
- CQI is for the terminal device to instruct the base station to the desired downlink modulation and coding rate, and is necessary for the base station to perform adaptive modulation and perform desired scheduling.
- CQI CQI
- a CQI is transmitted from a terminal device to a base station in order for the base station to perform appropriate adaptive modulation.
- CQI is 16-stage CSI (Channel State Information) indicated by 4 bits.
- the terminal apparatus can instruct the modulation method (either QPSK, 16QAM, or 64QAM) and the coding rate (from 0.08 to 0.93) to the base station by CQI.
- the base station uses the downlink control information (DCI) transmitted on the physical downlink control channel (PDCCH) to the terminal device for the CQI request.
- DCI downlink control information
- PDCCH physical downlink control channel
- Send CSI request Upon receiving this CSI request, the terminal device measures signal quality such as an S / N ratio in a resource block within a predetermined range, and calculates a CQI value based on the measurement result. Then, the terminal device transmits the calculated CQI value to the base station 4 subframes after receiving the CSI request.
- FIG. 5 is an explanatory diagram for explaining CRS, and shows an example of reference signals from antenna ports 0 to 3 for supporting MIMO with four antennas.
- the CRS is mapped while being shifted in the subcarrier direction by the remainder value modulo the cell ID value of 6.
- such a reference signal is inserted into all downlink subframes.
- the reference signal of each antenna port is not transmitted from the resource element in which the reference signal of another antenna port exists in order to avoid mutual interference. Thereby, the orthogonality between the reference signals is ensured.
- n s is the slot number
- l is the OFDM symbol number
- m is the index of the resource block.
- the left side indicates a CRS symbol value.
- c (n) represents the nth value of the gold sequence having a sequence length of 2 31 ⁇ 1, and two M sequences x 1 (n + N C ) and x 2 (n + N C )). That is, c (n) is given by the following equation.
- N C is a localization number
- N C 1600.
- each M series in the above formula is given by the following formula.
- the initial value x 2 (i) of the M sequence indicated by x 2 (n + N C ) is a 31-bit binary sequence that satisfies the following expression.
- the conventional CRS is mainly QPSK-modulated using a pseudo-random number generated using an initial value depending on the time / frequency position of the resource to be transmitted and the ID of the base station to be transmitted. Signal.
- the CRS is transmitted using different resource elements for each antenna. Thereby, interference between antennas is avoided, and each channel matrix is measured more accurately for each antenna.
- the terminal device receives the reference signal generated in this way, and excludes a fluctuating frequency error component as a pilot signal at the time of data demodulation based on the reference signal. Further, the terminal device measures the SNR of CRS and the like, and transmits a CQI desirable for the terminal to the base station.
- CSI-RS channel state information reference signal
- the transmission power of CRS may be set larger than the power of user data. In such a case, interference between adjacent cells may occur in CRS transmission.
- LTE TM9 (Transmission Mode 9) provides a means to determine CQI with higher accuracy by newly provided CSI-RS.
- FIG. 6 is an explanatory diagram for explaining CSI-RS, and shows an example of CSI-RS transmitted from antenna port 15.
- the transmission power can be kept relatively small, and the interference between cells is small.
- PDSCH Physical Downlink Shared Channel
- CSI-RS is set by configuration information for CSI-RS in RRC (Radio Resource Control) Connection Setup, RRC Connection Reconfiguration, RRC Connection Re-establishment. Since CSI-RS coexists with CRS, it is arranged at a position different from the resource element to which CRS is mapped.
- RRC Radio Resource Control
- the CSI-RS makes it possible to perform link adaptation in a more preferable manner in the downlink by enabling the determination of the CQI with higher accuracy by using a minimum amount of resources.
- the CSI-RS symbol value is defined by the same algorithm as CRS. That is, the CSI-RS symbol value is given by the following equation. In the following formula, the left side indicates a CSI-RS symbol value.
- N ID CSI As N ID CSI, above N ID cell is used.
- DM-RS demodulation reference signal
- DM-RS is a user-specific reference signal for each user, and is used in a transmission mode such as TM7, TM8, and TM9 that performs beamforming.
- the DM-RS is transmitted by beam forming in the same manner as data by being multiplied by a precoder coefficient at the base station.
- FIG. 7 is an explanatory diagram for explaining DM-RS, and shows an example of DM-RS in the case of antenna port 5.
- the symbol value of DM-RS in the case of antenna port 5 used in TM7 is expressed by the following equation.
- the left side indicates a DM-RS symbol value.
- the DM-RS used in TM7 takes a symbol value depending on the cell ID and RNTI (Radio Network Temporary ID).
- SCMA performs non-orthogonal user multiplexing using a codebook. Therefore, in SCMA, it is necessary to remove interference between users. According to such a system that allows a certain amount of interference between users, it is considered that multi-user MIMO can be efficiently performed without using advanced beamforming.
- SCMA in order to perform appropriate adaptive modulation and scheduling, it is considered necessary to provide appropriate information from the terminal to the base station, such as CQI in LTE.
- TM3 CQI is determined by receiving CRS.
- the transmission power of CRS is set to be larger than that of user data, and therefore, interference of CRS between adjacent cells may be a problem. Therefore, TM9 is provided with a means for performing CQI determination with higher accuracy using a new CSI-RS.
- CSI-RS is transmitted to the user data area (PDSCH), it is possible to suppress transmission power to a relatively low level and to suppress interference between cells. It becomes.
- the CSI-RS transmission can be stopped in order to measure the interference wave of the adjacent cell in the terminal device.
- an arbitrary QPSK symbol based on a sequence according to a pseudo-random number is used for a conventional reference signal used for determining CQI.
- SCMA is a method of performing non-orthogonal multiplexing using a code book and multiplexing data of a plurality of users on the same resource.
- SCMA a constellation mapping different from the conventional one is performed, for example, by using a multidimensional constellation and dividing the constellation into a plurality of resource elements.
- FIG. 8 is an explanatory diagram for explaining the mapping of the constellation in SCMA, and shows an example in which a 4-dimensional constellation signal is divided and mapped into two 2-dimensional constellations. Yes.
- SCMA these multidimensional constellations are used to multiplex them non-orthogonally (that is, to multiplex signals non-orthogonally between multiple layers), thereby further improving the frequency usage efficiency. It becomes possible.
- a base station in order to improve frequency use efficiency by non-orthogonal multiplexing of a multidimensional constellation mapped over a plurality of resources, such as SCMA, a base station has a more suitable codebook. It is desirable to be able to select a codebook combination (ie, a codebook group).
- the reference signal transmitted from the base station to the terminal device and the terminal device corresponding to the conventional CQI We propose a channel information provision method for base stations.
- FIG. 9 is an explanatory diagram illustrating an example of a schematic configuration of the system 1 according to an embodiment of the present disclosure.
- the system 1 includes a base station 100 and a terminal device 200. Note that a plurality of terminal devices 200 may be included.
- the system 1 includes terminal devices 200A to 200F.
- the terminal devices 200A to 200F may be simply referred to as “terminal device 200” unless otherwise distinguished.
- Base station 100 is a base station of a mobile communication system (or cellular system).
- the base station 100 performs wireless communication with a terminal device (for example, the terminal device 200) located in the cell 101.
- a terminal device for example, the terminal device 200
- the base station 100 transmits a downlink signal to the terminal device and receives an uplink signal from the terminal device.
- Terminal device 200 is a terminal device that can communicate in the mobile communication system (or cellular system).
- the terminal device 200 performs wireless communication with a base station (for example, the base station 100).
- the terminal device 200 receives a downlink signal from the base station and transmits an uplink signal to the base station.
- Non-orthogonal multiplexing using a code book In particular, in the embodiment of the present disclosure, non-orthogonal multiplexing / non-orthogonal multiple access using a code book is performed.
- the code book is an SC (Sparse Code) code book.
- SC Separatse Code
- the non-orthogonal multiple access using the code book is SCMA
- the non-orthogonal multiplexing using the code book is SCMA multiplexing.
- non-orthogonal multiplexing / non-orthogonal multiple access using a codebook is performed for the uplink.
- non-orthogonal multiplexing / non-orthogonal multiple access using a codebook may be performed for the uplink.
- FIG. 10 is a block diagram illustrating an exemplary configuration of the base station 100 according to the embodiment of the present disclosure.
- the base station 100 includes an antenna unit 110, a wireless communication unit 120, a network communication unit 130, a storage unit 140, and a processing unit 150.
- Antenna unit 110 The antenna unit 110 radiates a signal output from the wireless communication unit 120 to the space as a radio wave. Further, the antenna unit 110 converts radio waves in space into a signal and outputs the signal to the wireless communication unit 120.
- the wireless communication unit 120 transmits and receives signals.
- the radio communication unit 120 transmits a downlink signal to the terminal device and receives an uplink signal from the terminal device.
- the network communication unit 130 transmits and receives information.
- the network communication unit 130 transmits information to other nodes and receives information from other nodes.
- the other nodes include other base stations and core network nodes.
- Storage unit 140 The storage unit 140 temporarily or permanently stores a program for operating the base station 100 and various data.
- Processing unit 150 provides various functions of the base station 100.
- the processing unit 150 includes an allocation unit 151, a selection unit 153, an information acquisition unit 155, a notification unit 157, and a communication processing unit 159.
- the processing unit 150 may further include other components other than these components. That is, the processing unit 150 can perform operations other than the operations of these components.
- the allocation unit 151, the selection unit 153, the information acquisition unit 155, the notification unit 157, and the communication processing unit 159 will be described in detail later.
- FIG. 11 is a block diagram illustrating an exemplary configuration of the terminal device 200 according to an embodiment of the present disclosure.
- the terminal device 200 includes an antenna unit 210, a wireless communication unit 220, a storage unit 230, and a processing unit 240.
- Antenna unit 210 The antenna unit 210 radiates the signal output from the wireless communication unit 220 to the space as a radio wave. Further, the antenna unit 210 converts a radio wave in the space into a signal and outputs the signal to the wireless communication unit 220.
- the wireless communication unit 220 transmits and receives signals.
- the radio communication unit 220 receives a downlink signal from the base station and transmits an uplink signal to the base station.
- Storage unit 230 The storage unit 230 temporarily or permanently stores a program for operating the terminal device 200 and various data.
- the processing unit 240 provides various functions of the terminal device 200.
- the processing unit 240 includes an information acquisition unit 241 and a communication processing unit 243.
- the processing unit 240 may further include other components other than these components. That is, the processing unit 240 can perform operations other than the operations of these components.
- the information acquisition unit 241 and the communication processing unit 243 will be described in detail later.
- the base station 100 instructs the terminal device 200 to select a code book group (hereinafter referred to as “code book indication”). Request). Moreover, the base station 100 (communication processing unit 159) may transmit a reference signal for codebook indication to the terminal device 200 following the request for codebook indication. Then, base station 100 (communication processing unit 159) receives a codebook indication from terminal apparatus 200 as a response to the request (or the reference signal).
- the base station 100 (selection unit 153) can select a more suitable codebook group among a plurality of codebook groups based on the received codebook indication.
- the base station 100 (communication processing unit 159) performs communication processing for a plurality of layers based on the selected code book group.
- a Codebook group Each terminal that performs communication using SCMA demodulates the data subjected to SCMA modulation, and removes other multiplexed signals as interference waves. As well as other layer codebooks that are multiplexed simultaneously.
- Such a series of codebooks used to multiplex each signal element of a codeword generated for a series of layers in SCMA shall be referred to as a codebook group here for convenience. It should be noted that the combinations of the codebooks included in the codebook group are combinations that give a more preferable SCMA signal constellation that gives the maximum minimum intersymbol distance and the minimum signal power.
- FIG. 12 is an explanatory diagram for describing an example of a reference signal according to an embodiment of the present disclosure.
- a reference signal for causing the terminal device 200 to transmit a codebook indication may be referred to as “SCMA-RS” in order to distinguish it from other reference signals.
- SCMA-RS a reference signal for causing the terminal device 200 to transmit a codebook indication
- FIG. 4 an example will be described in which each signal element of the codeword generated for each of the six layers is mapped to four radio resources.
- SCMA-RS subcarriers and 4 resource elements per subframe are used for SCMA-RS transmission.
- the number of resource elements occupied by the SCMA-RS is more preferably the minimum necessary number as in the case of the CSI-RS described above.
- SCMA-RS is preferably arranged in the user data area (PDSCH) in the same way as CSI-RS from the viewpoint of coherence. Further, it is more desirable that the transmission power of SCMA-RS is set to be relatively smaller than that of CRS.
- the resource element in which the SCMA-RS is arranged does not overlap with existing reference signals (for example, CRS, CSI-RS, DM-RS, etc.).
- the SCMA-RS is preferably arranged in another resource element different from the resource element in which the existing reference signal is arranged.
- the SCMA-RS is generated by performing modulation in SCMA (hereinafter, referred to as “SCMA modulation” in some cases) on a predetermined sequence based on a code book used in SCMA.
- SCMA modulation hereinafter, referred to as “SCMA modulation” in some cases
- FIG. 13 is an explanatory diagram for explaining an example of a method for generating a reference signal (SCMA-RS) according to the present embodiment.
- the known sequences 1 to 6 are converted into code words in SCMA by the code books 1 to 6 included in the predetermined code book group.
- Each signal element of the codeword generated for each of the codebooks 1 to 6 (that is, the codeword of each layer) is multiplexed for each radio resource allocated to transmit the SCMA-RS. , SCMA-RS is generated.
- FIG. 14 is an explanatory diagram for explaining another example of the method for generating the reference signal (SCMA-RS) according to the present embodiment.
- SCMA-RS reference signal
- the SCMA-RS generation method shown in FIGS. 13 and 14 is merely an example, and a code word is generated from a plurality of sequences, and each signal element of the code word is multiplexed for each radio resource.
- the generation method is not particularly limited.
- the content of the sequence used for generating the SCMA-RS is not particularly limited as long as a process for indicating a code book based on the SCMA-RS described later can be executed. Note that an example of a sequence used for generating the SCMA-RS will be described later.
- the SCMA-RS generated for each radio resource is mapped to the corresponding radio resource, transmitted to the terminal apparatus 200, and demodulated in the terminal apparatus 200. Therefore, it is assumed that information of a code book for demodulating SCMA-RS (that is, a code book used for generating SCMA-RS) is shared in advance between base station 100 and terminal apparatus 200. It becomes. As a specific example, a predetermined fixed code book may be used as a code book for demodulating the SCMA-RS.
- a code book for demodulating SCMA-RS based on transmission / reception of information between base station 100 and terminal device 200 (in other words, a code book used to generate SCMA-RS). May be shared between the base station 100 and the terminal device 200. Specifically, the base station 100 may notify the terminal device 200 of a code book for demodulating the SCMA-RS using control information such as DCI.
- the SCMA-RS data described above may be generated in advance for each codebook group and stored in a predetermined storage area, for example.
- the base station 100 does not need to execute processing related to SCMA-RS generation at any time for each transmission timing of SCMA-RS.
- the example of the reference signal for performing the code book indication is described for the case of performing communication based on the code book for generating the signal of the four-dimensional constellation. It is not limited to the example shown.
- communication may be performed based on a code book that generates a 6-dimensional constellation signal.
- the SCMA-RS may be generated based on a code book for generating a 6-dimensional constellation signal.
- the base station 100 (communication processing unit 159) transmits a codebook indication request to the terminal device 200.
- the base station 100 (communication processing unit 159) notifies the terminal device 200 of a resource block used for SCMA-RS transmission.
- the base station 100 (communication processing unit 159) transmits the SCMA-RS to the terminal apparatus 200 using the resource block notified to the terminal apparatus 200. Note that details of processing related to transmission of the SCMA-RS will be described later together with a series of communication processing.
- the base station 100 may transmit a plurality of sets of SCMA-RSs to the terminal device 200 by using a plurality of resource blocks having different allocated subframes or frequency bands. .
- the base station 100 may transmit the SCMA-RS to the terminal device 200 for a plurality of codebook groups.
- the base station 100 (communication processing unit 159) may assign reference signals (SCMA-RS) generated based on different codebook groups for each resource block.
- FIG. 15 is an explanatory diagram for explaining an example of a transmission method of the reference signal (SCMA-RS) according to the present embodiment.
- the base station 100 (communication processing unit 159) performs reference signals (SCMA-) generated based on different codebook groups for radio resources of resource blocks assigned to different subframes. RS).
- FIG. 16 is an explanatory diagram for explaining another example of the reference signal (SCMA-RS) transmission method according to the present embodiment.
- the base station 100 uses the reference signals (SCMA-) generated based on different codebook groups for radio resources of resource blocks assigned to different frequency bands. RS).
- base station 100 (communication processing unit 159) allocates a reference signal (SCMA-RS) generated based on a different sequence (for example, a sequence having different initial values) for each resource block. Also good.
- SCMA-RS reference signal
- the terminal device 200 receives a request for codebook indication from the base station 100. Further, the terminal device 200 (communication processing unit 243) may acquire the SCMA-RS transmitted following the request based on the request. In this case, the terminal device 200 (communication processing unit 243) refers to the resource block notified from the base station 100 based on the codebook indication request, and extracts the SMCA-RS transmitted from the base station 100. .
- the terminal device 200 (communication processing unit 243), from the SCMA-RS, based on each codebook of the corresponding codebook group, a signal corresponding to each layer (that is, sequence 1 (Each signal element of the code word corresponding to ⁇ 6) is separated.
- the terminal device 200 (communication processing unit 243), based on the message transmission method described above, signals corresponding to each layer multiplexed on each radio resource (that is, multiplexed as SCMA-RS). May be separated.
- the terminal device 200 transmits the signal for each layer multiplexed in each radio resource as the SCMA-RS. Can be recognized. Therefore, the terminal device 200 (communication processing unit 243) generates a copy of a signal for each layer multiplexed in each radio resource (hereinafter may be referred to as a “replicated signal”) based on a known sequence.
- the duplicate signal may be used for separating signals corresponding to each layer multiplexed on each radio resource.
- the terminal device 200 corresponds to layer 1 from an SCMA-RS in which signals corresponding to layers 1, 3, and 5 (signal elements of codewords) are multiplexed. Focus on demodulating the signal.
- the terminal device 200 removes the duplicate signal components corresponding to the layers 3 and 5 generated based on the known sequence from the SCMA-RS, thereby changing the layer 1 to the layer 1. What is necessary is just to isolate
- the terminal apparatus 200 removes the duplicate signal components corresponding to layers 2 and 3 that are generated based on the known sequence from the SCMA-RS, to layer 6. What is necessary is just to isolate
- each layer is compared with a case where a message transmission method is used. No error propagates when separating the signals. Therefore, in this case, the codeword of each layer can be demodulated with higher accuracy from the SCMA-RS.
- the processing based on the message transmission method can be omitted, it is possible to reduce the processing load related to the demodulation of the codeword of each layer.
- the terminal device 200 (communication processing unit 243) separates signals corresponding to each layer from the received SCMA-RS.
- the terminal device 200 acquires information that is used as a reference for the base station 100 to select a codebook group by evaluating a signal corresponding to each separated layer. And the terminal device 200 (communication processing part 243) transmits the acquired information to the base station 100 as a code book indication.
- the terminal device 200 may measure a noise ratio (for example, a signal-to-noise ratio (SNR)) based on a signal corresponding to each separated layer.
- a noise ratio for example, a signal-to-noise ratio (SNR)
- the terminal device 200 (communication processing unit 243) may transmit the noise ratio measurement result to the base station 100 as a codebook indication.
- the terminal device 200 may calculate an error rate based on data (sequence) demodulated from a signal corresponding to each separated layer.
- the terminal device 200 (communication processing unit 243) may transmit the error rate calculation result to the base station 100 as a codebook indication.
- the terminal device 200 (communication processing unit 243) demodulates the codeword corresponding to each layer from the separated signal corresponding to each layer, and corresponds the demodulated codeword to the layer. To the original data (sequence) based on the code book to be used. And the terminal device 200 (information acquisition part 241) should just calculate an error rate based on the data by which the codeword was converted.
- the terminal device 200 may transmit the designation of the code book to be used to the base station 100 as a code book indication.
- the terminal device 200 (information acquisition unit 241) specifies a more suitable codebook based on the measurement result of the noise ratio, the calculation result of the error rate, and the like. Then, the terminal device 200 (communication processing unit 243) may transmit information indicating the identified code book (for example, an index value of the code book) to the base station 100 as a code book indication.
- the identified code book for example, an index value of the code book
- the terminal device 200 may transmit a codebook group designation to the base station 100 as a codebook indication.
- the terminal device 200 may acquire SCMA-RS for a plurality of codebook groups.
- the terminal device 200 (information acquisition unit 241) acquires information for reference by the base station 100 to select a codebook group for each acquired SCMA-RS (ie, for each codebook group). To do.
- the terminal device 200 (communication processing unit 243) may transmit a code book indication to the base station 100 based on information acquired for a plurality of code book groups.
- the terminal device 200 (communication processing unit 243) may transmit each piece of information acquired for a plurality of codebook groups to the base station 100 as a codebook indication.
- the terminal apparatus 200 transmits a codebook indication to the base station 100 based on the SCMA-RS transmitted from the base station 100 .
- the terminal device 200 can transmit, as a codebook indication, information used as a reference for the base station 100 to select a codebook group, the method is as follows: The method is not necessarily limited to the method using SCMA-RS.
- the terminal device 200 transmits information acquired by evaluating an existing reference signal such as CRS, CSI-RS, DM-RS, etc. to the base station 100 as a codebook indication. Also good.
- the information that the terminal device 200 transmits to the base station 100 as a codebook indication may not be information based on a signal (for example, a reference signal) transmitted from the base station 100.
- (D) Selection and notification of codebook group For example, the base station 100 (communication processing unit 159), after transmitting a codebook indication request to the terminal device 200 (or after transmitting the reference signal), A code book indication is received from the terminal device 200. At this time, the base station 100 (communication processing unit 159) may receive codebook indications for a plurality of codebook groups from the terminal device 200.
- the base station 100 selects a more suitable codebook group using the received codebook indication as reference information.
- the base station 100 determines a more suitable codebook group based on the reception quality (for example, noise ratio and error rate) of the signal notified from the terminal device 200 as the codebook indication. May be selected.
- the base station 100 may receive a codebook or codebook group designation from the terminal device 200 as a codebook indication. In this case, for example, the base station 100 (selection unit 153) may select a more suitable codebook group with reference to the designation of the codebook or codebook group from each terminal apparatus 200.
- the base station 100 notification unit 157) notifies the terminal device 200 of the selected code book group (that is, a code book group selected from a plurality of code book groups).
- the base station 100 notifies the terminal device 200 of the codebook group in DCI.
- the base station 100 (notification unit 157) generates DCI including information indicating the codebook group.
- the information indicating the code book group may be identification information of the code book group (for example, a group number of the code book group).
- the terminal device 200 can know the codebook group to be used.
- Terminal Device 200 Operation of Terminal Device
- the terminal device 200 (communication processing unit 243), based on the code book group corresponding to each layer notified from the base station 100 among the plurality of code book groups, A code word corresponding to each layer is separated, and received data is demodulated from the code word. Note that details of operations related to demodulation of received data by the terminal device 200 (communication processing unit 243) will be described later together with a series of flows of reception processing.
- the sequence used for generating the SCMA-RS is not necessarily a sequence known on the terminal device 200 side.
- the terminal device 200 (information acquisition unit 241) evaluates a signal corresponding to each layer separated from the SCMA-RS as an evaluation that does not depend on data that is a generation source of the signal, such as noise ratio evaluation.
- the SCMA-RS may be generated based on an unknown sequence.
- the SCMA-RS may be generated based on an existing sequence for which a generation algorithm is known, such as an M series or a gold sequence. Further, the sequences converted into codewords by the codebooks included in the codebook group may be different from each other as shown in FIG. 13, or the same sequence may be used at least in part. .
- a pseudo random code may be generated as the sequence by adding predetermined information as an initial value of the sequence for generating the SCMA-RS.
- identification information for example, index value
- identification information for identifying each codebook included in the codebook group may be used as an initial value of the sequence.
- identification information for example, index value for identifying the codebook group may be used as an initial value of the sequence.
- a value determined according to time such as a slot number, may be used as the initial value of the sequence.
- a pseudo-random code may be generated as the sequence by using a value that dynamically changes according to the situation as the initial value of the sequence.
- the accuracy of evaluation for codebook indication by the terminal device 200 can be improved.
- terminal apparatus 200 measures the noise ratio for each of a plurality of sets of SCMA-RSs based on sequences generated using mutually different initial values, and calculates the average value of the measurement results as a codebook indication. May be transmitted to the base station 100.
- the SCMA-RS used for measuring the noise ratio varies as appropriate according to the sequence that is the generation source, the noise ratio can be measured more accurately.
- the radio resource is a radio resource used for transmitting a codeword. More specifically, for example, the radio resource is a block corresponding to the length of the codeword. Hereinafter, an example of this block will be described with reference to FIG.
- FIG. 17 is an explanatory diagram for explaining an example of a block which is a radio resource used for transmitting a codeword.
- a carrier frequency band is shown.
- the carrier frequency band includes a plurality of blocks 10 (for example, blocks 10A to 10I).
- the length of the codeword ie, the number of signal elements included in the codeword
- the block 10 includes 4 subcarriers in the frequency direction.
- the subcarriers are arranged at intervals of 12 kHz.
- the block 10 includes a predetermined period in the time direction.
- the predetermined period is a symbol, a slot, a subframe, or a radio frame.
- the block 10 may be a resource block that is a unit of radio resource allocation, or may be a sub-resource block that is a part of the resource block.
- the base station 100 assigns one or more blocks 10 to the terminal device 200.
- the base station 100 assigns the same block 10 to two or more terminal devices 200.
- the base station 100 assigns the same block 10 to the terminal devices 200A to 200F.
- the block is not limited to such an example.
- the block may be discontinuous in the frequency direction. That is, the block may include two or more subcarriers that are discrete in the frequency direction.
- the length of the codeword (and the number of subcarriers included in the block) is 4
- the length (and the number) is not limited to this example.
- the length of the codeword (and the number of subcarriers included in the block) may be other lengths (and other numbers).
- the length (and the number) may be 6 or 12.
- the base station 100 (allocation unit 151) allocates each of a plurality of layers to be subjected to non-orthogonal multiplexing using a codebook to the terminal device 200.
- Non-orthogonal multiplexing using a code book As described above, for example, the code book is a code book of SC (Sparse Code), and the non-orthogonal multiplexing using the code book is SCMA multiplexing.
- SC Synchrone Code
- the multiple layers are SCMA layers.
- the number of layers in the plurality of layers is less than the maximum allowable number.
- the maximum allowable number is six. That is, the base station 100 (assignment unit 151) assigns each of the six or less layers to the terminal device 200.
- the base station 100 assigns each of six layers (layer 1 to layer 6) to the terminal device 200.
- the base station 100 assigns each of five layers (five out of layers 1 to 6) to the terminal device 200.
- the base station 100 (allocation unit 151) allocates each of the plurality of layers to a different terminal device 200.
- the base station 100 assigns layer 1 to the terminal device 200A, assigns layer 2 to the terminal device 200B, assigns layer 3 to the terminal device 200C, assigns layer 4 to the terminal device 200D, 5 is assigned to the terminal device 200E, and layer 6 is assigned to the terminal device 200F.
- more terminal apparatuses 200 can communicate simultaneously.
- the base station 100 may assign two or more layers to the same terminal device 200.
- the base station 100 may assign layer 1 and layer 2 to the terminal device 200A. Thereby, for example, the communication speed of the terminal device 200A can be improved.
- the base station 100 (information acquisition unit 155) assigns to the terminal device 200 among the plurality of layers (that is, a plurality of layers to be subjected to non-orthogonal multiplexing using a codebook). Information indicating the layer to be recorded is acquired. Then, the base station 100 (notification unit 157) notifies the terminal device 200 of the layer.
- the terminal device 200 can know the layer assigned to the terminal device 200.
- DCI Downlink Control Information
- the DCI is information transmitted on a physical downlink control channel (PDCCH).
- PDCH physical downlink control channel
- the base station 100 (notification unit 157) notifies the terminal device 200A of the layer 1 assigned to the terminal device 200A in the DCI to the terminal device 200A.
- the base station 100 (notifying unit 157) notifies the terminal device 200D of the layer 4 assigned to the terminal device 200D in the DCI to the terminal device 200D.
- the terminal apparatus 200 can flexibly perform DRX operation and / or semi-persistent communication even when non-orthogonal multiplexing using a codebook is used.
- the base station 100 (notification unit 157) generates DCI including information indicating the layer.
- the information indicating the layer may be a layer number of the layer.
- the base station 100 (communication processing unit 159) generates a CRC based on the ID (eg, RNTI: Radio Network Temporary ID) of the terminal device 200, and adds the CRC to the DCI. Then, the base station 100 (communication processing unit 159) performs encoding, rate matching, multiplexing, and the like on the DCI to which the CRC is added.
- ID eg, RNTI: Radio Network Temporary ID
- the base station 100 (communication processing unit 159) performs encoding, rate matching, multiplexing, and the like on the DCI to which the CRC is added.
- the terminal device 200 monitors the PDCCH of each subframe based on the ID (for example, RNTI) of the terminal device 200, and finds the DCI to the terminal device 200. Then, the terminal device 200 (information acquisition unit 241) acquires the DCI, and acquires the information indicating the layer included in the DCI.
- ID for example, RNTI
- the base station 100 notifies the terminal device 200 of radio resources used for transmission of the codeword of the layer in the DCI. Thereby, for example, the terminal device 200 can know which radio resource is assigned to the terminal device 200.
- the base station 100 may notify the terminal device 200 of other information according to the transmission mode in the DCI.
- the other information may include MCS (Modulation and Coding Scheme), NDI (New Data Indicator), power control command of physical uplink control channel (Physical Uplink Control Channel: PUCCH), and / or precoding information. .
- the base station 100 (communication processing unit 159) performs communication processing on the plurality of layers (that is, a plurality of layers to be subjected to non-orthogonal multiplexing using a codebook).
- the terminal device 200 acquires information indicating a layer assigned to the terminal device 200 among the plurality of layers. And the terminal device 200 (communication processing part 243) performs the communication process about the said layer based on the said information which shows the said layer.
- (A) Downlink case For example, the non-orthogonal multiplexing is performed on the downlink.
- the base station 100 (communication processing unit 159) performs transmission processing for the plurality of layers.
- the terminal device 200 (communication processing unit 243) performs reception processing on the layer assigned to the terminal device 200 among the plurality of layers.
- the transmission process includes, for each of the plurality of layers, generating a codeword of the layer from layer data.
- the base station 100 (communication processing unit 159) generates a codeword of the layer from the data of the layer based on the codebook for the layer.
- the base station 100 (communication processing unit 159) generates a layer 1 codeword from layer 1 data based on a codebook for layer 1 (for example, codebook 1 shown in FIG. 3). Further, as another example, the base station 100 (communication processing unit 159), based on the code book for layer 4 (for example, the code book 4 shown in FIG. 3), converts the layer 4 data into the layer 4 code. Generate a word.
- the code book used for generating the code word may be a code book included in a code book group selected based on the code book indication from the terminal device 200, for example.
- the transmission process includes mapping the codewords to radio resources used for transmission of the codewords for each of the plurality of layers.
- the base station 100 maps the codeword to the same block for each of the plurality of layers. More specifically, for example, the base station 100 (communication processing unit 159) maps each signal element in the codeword of each layer to a corresponding radio resource (for example, resource element) in the block.
- a radio resource for example, resource element
- the base station 100 (communication processing unit 159) performs multiplexing by mapping codewords of a plurality of layers to the same block. Although signal elements of codewords of different layers are mapped to the same resource element, the signal elements may be mapped to the same resource element after addition, and It may be added after mapping.
- the base station 100 maps various reference signals to predetermined resource elements.
- An example of the reference signal is a frequency synchronization reference signal such as CRS.
- the base station 100 maps the reference signal (SCMA-RS) used for the SCMA channel evaluation according to the present embodiment described above to the radio resource allocated to the reference signal. Also good. Thereby, base station 100 (communication processing unit 159) receives the codebook indication based on the SCMA-RS from terminal apparatus 200, and selects a more suitable codebook group based on the codebook indication. Is possible. Note that the code book group selected at this time is used for SCMA modulation of the data when data is transmitted to the terminal device 200 after reception of the code book indication.
- SCMA-RS reference signal
- FIG. 18 is an explanatory diagram for describing a first example of the overall transmission process of the base station 100.
- the transmission processing of the base station 100 includes encoding, layer mapping, codeword generation based on a codeword, resource mapping, IFFT (Inverse Fast Fourier Transform), and the like.
- FIG. 19 is an explanatory diagram for describing a second example of the entire transmission processing of the base station 100.
- the second example is an example of MIMO (Multiple-Input and Multiple-Output) case.
- MIMO Multiple-Input and Multiple-Output
- a case where beam forming by a precoder is accompanied for spatial multiplexing will be described.
- the transmission processing of the base station 100 includes the second layer for spatial multiplexing in addition to the first layer mapping for non-orthogonal multiplexing using a codebook. Includes layer mapping. Further, the transmission process includes precoding for spatial multiplexing.
- the codeword is mapped to the transmission layer in the second layer mapping, weighted for each antenna in the precoding, and transmitted.
- the number of transmission layers is determined with reference to RI (Rank Indicator) that the terminal device 200 notifies the base station 100 of.
- the set of weights in the precoding is selected from a set group determined in advance so that the total throughput of each layer is maximized.
- the set of weights in the precoding is determined with reference to a PMI (Precoding Matrix Indicator) that the terminal device 200 notifies the base station 100 of.
- the above-mentioned SCMA-RS may be transmitted with weighting for each antenna in the precoding as in the case of the codeword.
- the SCMA-RS is given directivity like the code word.
- A-2) Reception Process of Terminal Device 200 -Demapping of Received Signal from Radio Resource For example, the reception process includes demapping a received signal from a radio resource allocated to the terminal device 200.
- the terminal device 200 demaps a received signal in which signal elements of codewords of different layers are multiplexed from radio resources used for transmission of codewords.
- the terminal device 200 demaps the reference signal from radio resources used for transmission of various reference signals.
- an existing reference signal such as a frequency synchronization reference signal (CRS), a reference signal (SCMA-RS) used for channel evaluation of SCMA, and the like are demapped.
- CRS frequency synchronization reference signal
- SCMA-RS reference signal
- the reception process includes demodulating data of each layer subjected to SCMA modulation by SIC.
- the terminal device 200 (communication processing unit 243) demodulates the data of each layer based on the codebook for each layer.
- the terminal device 200 (communication processing unit 243), based on a code signal for each layer, from the received signal in the radio resource allocated to the terminal device 200, data of a desired layer (that is, each layer) Codeword signal elements). Specifically, when separating the layer 1 data from the received signal, the terminal device 200 (communication processing unit 243) removes signals (interference) of layers other than layer 1 by SIC, The layer 1 data is separated. Note that the terminal device 200 uses the SIC to perform layer 1 data based on not only the code book for the layer 1 but also the code book for the other layer in order to remove the signal of the other layer. Isolate.
- the terminal device 200 demodulates the codeword of the layer from the data (that is, the codeword signal element) separated for each layer from the received signal in the radio resource. And the terminal device 200 (communication processing part 243) decodes the data of the said layer from the codeword of each layer demodulated based on the codebook for the said layer.
- the terminal device 200 decodes the data of the layer assigned to itself.
- the reception processing includes demodulating data (that is, a sequence corresponding to each layer) used for SCMA channel evaluation by decoding SCMA-RS by SIC.
- the terminal device 200 may demodulate the SCMA-RS by SIC as in the case of demodulating the SCMA modulated data described above.
- the terminal device 200 (communication processing unit 243) generates a duplicate signal based on the known sequence, and the duplicate signal is transmitted to each layer. May be used to demodulate a sequence corresponding to. Note that the method of demodulating the SCMA-RS by using a duplicate signal generated based on a known sequence is as described above.
- FIG. 20 is an explanatory diagram for describing a first example of the overall reception processing of the terminal device 200.
- the reception processing of the terminal device 200 includes FFT (Fast Fourier Transform), resource demapping, SCMA demodulation, layer mapping, decoding, and the like.
- FIG. 21 is an explanatory diagram for describing a second example of the entire reception process of the terminal device 200.
- the second example is an example of the MIMO case.
- the reception processing of the terminal device 200 is spatially multiplexed in addition to the first layer demapping that extracts the data of each layer from the decoding result of the SCMA modulated data. Includes a second layer demapping to retrieve each signal.
- the terminal device 200 (communication processing unit 243) performs a demapping process on signals received via a plurality of antennas, thereby obtaining a space from the radio resources allocated to the terminal device 200. Demultiplex the multiplexed received signal.
- the terminal device 200 (communication processing unit 243) performs demapping processing on the signal received for each antenna, thereby demapping the reference signal from radio resources used for transmission of various reference signals. To do. Thereby, for example, existing reference signals such as CRS, CSI-RS, DM-RS, etc. are demapped.
- the terminal device 200 estimates the spatial channel matrix H based on the demapped reference signal, and calculates the reception weight matrix W from the estimated channel matrix H based on, for example, the MMSE algorithm.
- the terminal device 200 (communication processing unit 243), based on the calculated reception weight matrix W, transmits a codeword of a different layer transmitted from a spatially multiplexed received signal using radio resources used for transmitting the codeword. A received signal in which signal elements are multiplexed is extracted.
- the terminal device 200 (communication processing unit 243) demodulates the data of each layer based on the codebook for each layer from the extracted received signal.
- the terminal device 200 (communication processing unit 243) takes out the spatially multiplexed SCMA-RS based on the calculated reception weight matrix W, similarly to the data of each layer. Then, the terminal device 200 (communication processing unit 243) decodes the SCMA-RS based on the codebook for each layer, so that data used for SCMA channel evaluation (that is, a sequence corresponding to each layer). Is demodulated.
- (B) Uplink case The non-orthogonal multiplexing may be performed on the uplink.
- the terminal device 200 (communication processing unit 243) may perform transmission processing on the layer assigned to the terminal device 200 among the plurality of layers.
- the base station 100 (communication processing unit 159) may perform reception processing for the plurality of layers.
- the transmission processing may include generating a codeword of the layer from data of a layer assigned to the terminal device 200.
- the terminal device 200 (communication processing unit 243) may generate the codeword of the layer from the layer data based on the codebook for the layer.
- layer 1 may be assigned to terminal device 200A, and terminal device 200A (communication processing unit 243) may use layer 1 based on code book 1 (code book for layer 1) shown in FIG.
- code book 1 code book for layer 1
- a layer 1 codeword may be generated from the data.
- the transmission process includes the radio resources used for transmission of the codewords of the layer allocated to the terminal device 200 (that is, radio resources allocated to the terminal device 200), Mapping the codewords of the layer may be included.
- the reception processing may include sequentially decoding data of each of the plurality of layers by SIC.
- the base station 100 (communication processing unit 159) may sequentially decode the data of each of the plurality of layers based on the codebook of the plurality of layers.
- layers 1 to 6 may be assigned to the terminal devices 200A to 200F, and the base station 100 (communication processing unit 159) may sequentially decode each data of layers 1 to 6 by SIC.
- FIG. 22 is a sequence diagram illustrating an example of a schematic flow of processing according to an embodiment of the present disclosure.
- the example shown in FIG. 22 shows an example of processing related to codebook indication using SCMA-RS.
- Step S101 The base station 100 requests the terminal device 200 for an indication for selecting a codebook group (that is, a codebook indication). At this time, the base station 100 notifies the terminal device 200 of a resource block used for SCMA-RS transmission.
- a codebook group that is, a codebook indication
- Step S103 base station 100 transmits, to terminal device 200, a reference signal (ie, SCMA-RS) for codebook indication to terminal device 200.
- a reference signal ie, SCMA-RS
- the base station 100 may transmit a plurality of sets of SCMA-RSs to the terminal device 200 by using a plurality of resource blocks having different assigned subframes or different frequency bands.
- Step S105 When receiving the codebook indication request from the base station 100, the terminal device 200 acquires the SCMA-RS transmitted subsequently based on the request. Specifically, the terminal device 200 refers to the resource block notified from the base station 100 based on the codebook indication request, and extracts the SMCA-RS transmitted from the base station 100.
- the terminal device 200 separates the signal corresponding to each layer from the extracted SCMA-RS based on each codebook of the corresponding codebook group.
- the terminal device 200 obtains information used as a reference for the base station 100 to select a codebook group by evaluating a signal corresponding to each separated layer.
- the terminal device 200 may measure a noise ratio (for example, a signal-to-noise ratio (SNR)) based on a signal corresponding to each separated layer.
- a noise ratio for example, a signal-to-noise ratio (SNR)
- the terminal device 200 may calculate an error rate based on data (sequence) demodulated from a signal corresponding to each separated layer.
- the terminal device 200 may specify a more suitable codebook based on the measurement result of the noise ratio, the calculation result of the error rate, or the like.
- Step S107 And the terminal device 200 transmits the acquired information to the base station 100 as a codebook indication.
- the base station 100 can select a more suitable codebook group using the codebook indication received from the terminal device 200 as reference information.
- the base station 100 may be realized as any type of eNB (evolved Node B) such as a macro eNB or a small eNB.
- the small eNB may be an eNB that covers a cell smaller than a macro cell, such as a pico eNB, a micro eNB, or a home (femto) eNB.
- the base station 100 may be realized as another type of base station such as a NodeB or a BTS (Base Transceiver Station).
- Base station 100 may include a main body (also referred to as a base station apparatus) that controls radio communication, and one or more RRHs (Remote Radio Heads) that are arranged at locations different from the main body. Further, various types of terminals described later may operate as the base station 100 by temporarily or semi-permanently executing the base station function. Furthermore, at least some components of the base station 100 may be realized in a base station apparatus or a module for the base station apparatus.
- RRHs Remote Radio Heads
- the terminal device 200 is a smartphone, a tablet PC (Personal Computer), a notebook PC, a portable game terminal, a mobile terminal such as a portable / dongle type mobile router or a digital camera, or an in-vehicle terminal such as a car navigation device. It may be realized as.
- the terminal device 200 may be realized as a terminal (also referred to as an MTC (Machine Type Communication) terminal) that performs M2M (Machine To Machine) communication.
- MTC Machine Type Communication
- M2M Machine To Machine
- at least a part of the components of the terminal device 200 may be realized in a module (for example, an integrated circuit module configured by one die) mounted on these terminals.
- FIG. 23 is a block diagram illustrating a first example of a schematic configuration of an eNB to which the technology according to the present disclosure may be applied.
- the eNB 800 includes one or more antennas 810 and a base station device 820. Each antenna 810 and the base station apparatus 820 can be connected to each other via an RF cable.
- Each of the antennas 810 has a single or a plurality of antenna elements (for example, a plurality of antenna elements constituting a MIMO antenna), and is used for transmission and reception of radio signals by the base station apparatus 820.
- the eNB 800 includes a plurality of antennas 810 as illustrated in FIG. 23, and the plurality of antennas 810 may respectively correspond to a plurality of frequency bands used by the eNB 800, for example. 23 shows an example in which the eNB 800 includes a plurality of antennas 810, the eNB 800 may include a single antenna 810.
- the base station apparatus 820 includes a controller 821, a memory 822, a network interface 823, and a wireless communication interface 825.
- the controller 821 may be a CPU or a DSP, for example, and operates various functions of the upper layer of the base station apparatus 820. For example, the controller 821 generates a data packet from the data in the signal processed by the wireless communication interface 825, and transfers the generated packet via the network interface 823. The controller 821 may generate a bundled packet by bundling data from a plurality of baseband processors, and may transfer the generated bundled packet. In addition, the controller 821 is a logic that executes control such as radio resource control, radio bearer control, mobility management, inflow control, or scheduling. May have a typical function. Moreover, the said control may be performed in cooperation with a surrounding eNB or a core network node.
- the memory 822 includes RAM and ROM, and stores programs executed by the controller 821 and various control data (for example, terminal list, transmission power data, scheduling data, and the like).
- the network interface 823 is a communication interface for connecting the base station device 820 to the core network 824.
- the controller 821 may communicate with the core network node or other eNB via the network interface 823.
- the eNB 800 and the core network node or another eNB may be connected to each other by a logical interface (for example, an S1 interface or an X2 interface).
- the network interface 823 may be a wired communication interface or a wireless communication interface for wireless backhaul.
- the network interface 823 may use a frequency band higher than the frequency band used by the wireless communication interface 825 for wireless communication.
- the wireless communication interface 825 supports any cellular communication scheme such as LTE (Long Term Evolution) or LTE-Advanced, and provides a wireless connection to terminals located in the cell of the eNB 800 via the antenna 810.
- the wireless communication interface 825 may typically include a baseband (BB) processor 826, an RF circuit 827, and the like.
- the BB processor 826 may perform, for example, encoding / decoding, modulation / demodulation, and multiplexing / demultiplexing, and each layer (for example, L1, MAC (Medium Access Control), RLC (Radio Link Control), and PDCP).
- Various signal processing of Packet Data Convergence Protocol
- Packet Data Convergence Protocol is executed.
- the BB processor 826 may have some or all of the logical functions described above instead of the controller 821.
- the BB processor 826 may be a module that includes a memory that stores a communication control program, a processor that executes the program, and related circuits. The function of the BB processor 826 may be changed by updating the program. Good.
- the module may be a card or a blade inserted into a slot of the base station apparatus 820, or a chip mounted on the card or the blade.
- the RF circuit 827 may include a mixer, a filter, an amplifier, and the like, and transmits and receives a radio signal via the antenna 810.
- the wireless communication interface 825 includes a plurality of BB processors 826 as illustrated in FIG. 23, and the plurality of BB processors 826 may respectively correspond to a plurality of frequency bands used by the eNB 800, for example. Further, the wireless communication interface 825 includes a plurality of RF circuits 827 as shown in FIG. 23, and the plurality of RF circuits 827 may respectively correspond to a plurality of antenna elements, for example. 23 shows an example in which the wireless communication interface 825 includes a plurality of BB processors 826 and a plurality of RF circuits 827, the wireless communication interface 825 includes a single BB processor 826 or a single RF circuit 827. But you can.
- one or more components may be implemented in the wireless communication interface 825.
- the eNB 800 includes a module including a part (for example, the BB processor 826) or all of the wireless communication interface 825 and / or the controller 821, and the one or more components are mounted in the module. Good.
- the module stores a program for causing the processor to function as the one or more components (in other words, a program for causing the processor to execute the operation of the one or more components).
- the program may be executed.
- a program for causing a processor to function as the one or more components is installed in the eNB 800, and the radio communication interface 825 (eg, the BB processor 826) and / or the controller 821 executes the program.
- the eNB 800, the base station apparatus 820, or the module may be provided as an apparatus including the one or more components, and a program for causing a processor to function as the one or more components is provided. May be.
- a readable recording medium in which the program is recorded may be provided.
- the radio communication unit 120 described with reference to FIG. 10 may be implemented in the radio communication interface 825 (for example, the RF circuit 827) in the eNB 800 illustrated in FIG. Further, the antenna unit 110 may be mounted on the antenna 810.
- the network communication unit 130 may be implemented in the controller 821 and / or the network interface 823.
- FIG. 24 is a block diagram illustrating a second example of a schematic configuration of an eNB to which the technology according to the present disclosure may be applied.
- the eNB 830 includes one or more antennas 840, a base station apparatus 850, and an RRH 860. Each antenna 840 and RRH 860 may be connected to each other via an RF cable. Base station apparatus 850 and RRH 860 can be connected to each other via a high-speed line such as an optical fiber cable.
- Each of the antennas 840 has a single or a plurality of antenna elements (for example, a plurality of antenna elements constituting a MIMO antenna), and is used for transmission / reception of radio signals by the RRH 860.
- the eNB 830 includes a plurality of antennas 840 as illustrated in FIG. 24, and the plurality of antennas 840 may respectively correspond to a plurality of frequency bands used by the eNB 830, for example. 24 shows an example in which the eNB 830 has a plurality of antennas 840, but the eNB 830 may have a single antenna 840.
- the base station device 850 includes a controller 851, a memory 852, a network interface 853, a wireless communication interface 855, and a connection interface 857.
- the controller 851, the memory 852, and the network interface 853 are the same as the controller 821, the memory 822, and the network interface 823 described with reference to FIG.
- the wireless communication interface 855 supports a cellular communication method such as LTE or LTE-Advanced, and provides a wireless connection to a terminal located in a sector corresponding to the RRH 860 via the RRH 860 and the antenna 840.
- the wireless communication interface 855 may typically include a BB processor 856 and the like.
- the BB processor 856 is the same as the BB processor 826 described with reference to FIG. 23 except that the BB processor 856 is connected to the RF circuit 864 of the RRH 860 via the connection interface 857.
- the wireless communication interface 855 includes a plurality of BB processors 856 as illustrated in FIG.
- the plurality of BB processors 856 may respectively correspond to a plurality of frequency bands used by the eNB 830, for example.
- 24 shows an example in which the wireless communication interface 855 includes a plurality of BB processors 856, the wireless communication interface 855 may include a single BB processor 856.
- connection interface 857 is an interface for connecting the base station device 850 (wireless communication interface 855) to the RRH 860.
- the connection interface 857 may be a communication module for communication on the high-speed line that connects the base station apparatus 850 (wireless communication interface 855) and the RRH 860.
- the RRH 860 includes a connection interface 861 and a wireless communication interface 863.
- connection interface 861 is an interface for connecting the RRH 860 (wireless communication interface 863) to the base station device 850.
- the connection interface 861 may be a communication module for communication on the high-speed line.
- the wireless communication interface 863 transmits and receives wireless signals via the antenna 840.
- the wireless communication interface 863 may typically include an RF circuit 864 and the like.
- the RF circuit 864 may include a mixer, a filter, an amplifier, and the like, and transmits and receives a radio signal via the antenna 840.
- the wireless communication interface 863 includes a plurality of RF circuits 864 as illustrated in FIG. 24, and the plurality of RF circuits 864 may correspond to, for example, a plurality of antenna elements, respectively. 24 shows an example in which the wireless communication interface 863 includes a plurality of RF circuits 864, the wireless communication interface 863 may include a single RF circuit 864.
- one or more components included in the processing unit 150 described with reference to FIG. Unit 159) may be implemented in the wireless communication interface 855 and / or the wireless communication interface 863. Alternatively, at least some of these components may be implemented in the controller 851.
- the eNB 830 includes a module including a part (for example, the BB processor 856) or the whole of the wireless communication interface 855 and / or the controller 851, and the one or more components are mounted in the module. Good.
- the module stores a program for causing the processor to function as the one or more components (in other words, a program for causing the processor to execute the operation of the one or more components).
- the program may be executed.
- a program for causing a processor to function as the one or more components is installed in the eNB 830, and the wireless communication interface 855 (eg, the BB processor 856) and / or the controller 851 executes the program.
- the eNB 830, the base station apparatus 850, or the module may be provided as an apparatus including the one or more components, and a program for causing a processor to function as the one or more components is provided. May be.
- a readable recording medium in which the program is recorded may be provided.
- the radio communication unit 120 described with reference to FIG. 10 may be implemented in the radio communication interface 863 (for example, the RF circuit 864).
- the antenna unit 110 may be mounted on the antenna 840.
- the network communication unit 130 may be implemented in the controller 851 and / or the network interface 853.
- FIG. 25 is a block diagram illustrating an example of a schematic configuration of a smartphone 900 to which the technology according to the present disclosure can be applied.
- the smartphone 900 includes a processor 901, a memory 902, a storage 903, an external connection interface 904, a camera 906, a sensor 907, a microphone 908, an input device 909, a display device 910, a speaker 911, a wireless communication interface 912, one or more antenna switches 915.
- One or more antennas 916, a bus 917, a battery 918 and an auxiliary controller 919 are provided.
- the processor 901 may be, for example, a CPU or a SoC (System on Chip), and controls the functions of the application layer and other layers of the smartphone 900.
- the memory 902 includes a RAM and a ROM, and stores programs executed by the processor 901 and data.
- the storage 903 can include a storage medium such as a semiconductor memory or a hard disk.
- the external connection interface 904 is an interface for connecting an external device such as a memory card or a USB (Universal Serial Bus) device to the smartphone 900.
- the camera 906 includes, for example, an image sensor such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor), and generates a captured image.
- the sensor 907 may include a sensor group such as a positioning sensor, a gyro sensor, a geomagnetic sensor, and an acceleration sensor.
- the microphone 908 converts sound input to the smartphone 900 into an audio signal.
- the input device 909 includes, for example, a touch sensor that detects a touch on the screen of the display device 910, a keypad, a keyboard, a button, or a switch, and receives an operation or information input from a user.
- the display device 910 has a screen such as a liquid crystal display (LCD) or an organic light emitting diode (OLED) display, and displays an output image of the smartphone 900.
- the speaker 911 converts an audio signal output from the smartphone 900 into audio.
- the wireless communication interface 912 supports any cellular communication method such as LTE or LTE-Advanced, and performs wireless communication.
- the wireless communication interface 912 may typically include a BB processor 913, an RF circuit 914, and the like.
- the BB processor 913 may perform, for example, encoding / decoding, modulation / demodulation, and multiplexing / demultiplexing, and performs various signal processing for wireless communication.
- the RF circuit 914 may include a mixer, a filter, an amplifier, and the like, and transmits and receives radio signals via the antenna 916.
- the wireless communication interface 912 may be a one-chip module in which the BB processor 913 and the RF circuit 914 are integrated.
- the wireless communication interface 912 may include a plurality of BB processors 913 and a plurality of RF circuits 914 as illustrated in FIG.
- FIG. 25 illustrates an example in which the wireless communication interface 912 includes a plurality of BB processors 913 and a plurality of RF circuits 914.
- the wireless communication interface 912 includes a single BB processor 913 or a single RF circuit 914. But you can.
- the wireless communication interface 912 may support other types of wireless communication methods such as a short-range wireless communication method, a proximity wireless communication method, or a wireless LAN (Local Area Network) method in addition to the cellular communication method.
- a BB processor 913 and an RF circuit 914 for each wireless communication method may be included.
- Each of the antenna switches 915 switches the connection destination of the antenna 916 among a plurality of circuits (for example, circuits for different wireless communication systems) included in the wireless communication interface 912.
- Each of the antennas 916 includes a single or a plurality of antenna elements (for example, a plurality of antenna elements constituting a MIMO antenna), and is used for transmission / reception of a radio signal by the radio communication interface 912.
- the smartphone 900 may include a plurality of antennas 916 as illustrated in FIG. Note that although FIG. 25 illustrates an example in which the smartphone 900 includes a plurality of antennas 916, the smartphone 900 may include a single antenna 916.
- the smartphone 900 may include an antenna 916 for each wireless communication method.
- the antenna switch 915 may be omitted from the configuration of the smartphone 900.
- the bus 917 connects the processor 901, memory 902, storage 903, external connection interface 904, camera 906, sensor 907, microphone 908, input device 909, display device 910, speaker 911, wireless communication interface 912, and auxiliary controller 919 to each other.
- the battery 918 supplies power to each block of the smartphone 900 illustrated in FIG. 25 via a power supply line partially illustrated by a broken line in the drawing.
- the auxiliary controller 919 operates the minimum necessary functions of the smartphone 900 in the sleep mode.
- the information acquisition unit 241 and the communication processing unit 243 described with reference to FIG. 11 may be implemented in the wireless communication interface 912. Alternatively, at least some of these components may be implemented in the processor 901 or the auxiliary controller 919.
- the smartphone 900 includes a module including a part (for example, the BB processor 913) or the whole of the wireless communication interface 912, the processor 901, and / or the auxiliary controller 919, and the information acquisition unit 241 and the communication processing are included in the module.
- the unit 243 may be mounted.
- the module executes a program for causing the processor to function as the information acquisition unit 241 and the communication processing unit 243 (in other words, a program for causing the processor to execute the operations of the information acquisition unit 241 and the communication processing unit 243).
- a program for causing a processor to function as the information acquisition unit 241 and the communication processing unit 243 is installed in the smartphone 900, and the wireless communication interface 912 (for example, the BB processor 913), the processor 901, and / or the auxiliary controller 919 is installed. May execute the program.
- the smartphone 900 or the module may be provided as an apparatus including the information acquisition unit 241 and the communication processing unit 243, and a program for causing the processor to function as the information acquisition unit 241 and the communication processing unit 243 is provided. May be.
- a readable recording medium in which the program is recorded may be provided.
- the wireless communication unit 220 described with reference to FIG. 11 may be implemented in the wireless communication interface 912 (for example, the RF circuit 914).
- the antenna unit 210 may be mounted on the antenna 916.
- FIG. 26 is a block diagram illustrating an example of a schematic configuration of a car navigation device 920 to which the technology according to the present disclosure can be applied.
- the car navigation device 920 includes a processor 921, a memory 922, a GPS (Global Positioning System) module 924, a sensor 925, a data interface 926, a content player 927, a storage medium interface 928, an input device 929, a display device 930, a speaker 931, and wireless communication.
- the interface 933 includes one or more antenna switches 936, one or more antennas 937, and a battery 938.
- the processor 921 may be a CPU or SoC, for example, and controls the navigation function and other functions of the car navigation device 920.
- the memory 922 includes RAM and ROM, and stores programs and data executed by the processor 921.
- the GPS module 924 measures the position (for example, latitude, longitude, and altitude) of the car navigation device 920 using GPS signals received from GPS satellites.
- the sensor 925 may include a sensor group such as a gyro sensor, a geomagnetic sensor, and an atmospheric pressure sensor.
- the data interface 926 is connected to the in-vehicle network 941 through a terminal (not shown), for example, and acquires data generated on the vehicle side such as vehicle speed data.
- the content player 927 reproduces content stored in a storage medium (for example, CD or DVD) inserted into the storage medium interface 928.
- the input device 929 includes, for example, a touch sensor, a button, or a switch that detects a touch on the screen of the display device 930, and receives an operation or information input from a user.
- the display device 930 has a screen such as an LCD or an OLED display, and displays a navigation function or an image of content to be reproduced.
- the speaker 931 outputs the navigation function or the audio of the content to be played back.
- the wireless communication interface 933 supports any cellular communication method such as LTE or LTE-Advanced, and performs wireless communication.
- the wireless communication interface 933 may typically include a BB processor 934, an RF circuit 935, and the like.
- the BB processor 934 may perform, for example, encoding / decoding, modulation / demodulation, and multiplexing / demultiplexing, and performs various signal processing for wireless communication.
- the RF circuit 935 may include a mixer, a filter, an amplifier, and the like, and transmits and receives a radio signal via the antenna 937.
- the wireless communication interface 933 may be a one-chip module in which the BB processor 934 and the RF circuit 935 are integrated.
- the wireless communication interface 933 may include a plurality of BB processors 934 and a plurality of RF circuits 935 as shown in FIG. 26 shows an example in which the wireless communication interface 933 includes a plurality of BB processors 934 and a plurality of RF circuits 935, the wireless communication interface 933 includes a single BB processor 934 or a single RF circuit 935. But you can.
- the wireless communication interface 933 may support other types of wireless communication methods such as a short-range wireless communication method, a proximity wireless communication method, or a wireless LAN method in addition to the cellular communication method.
- a BB processor 934 and an RF circuit 935 may be included for each communication method.
- Each of the antenna switches 936 switches the connection destination of the antenna 937 among a plurality of circuits included in the wireless communication interface 933 (for example, circuits for different wireless communication systems).
- Each of the antennas 937 has a single or a plurality of antenna elements (for example, a plurality of antenna elements constituting a MIMO antenna), and is used for transmission / reception of a radio signal by the radio communication interface 933.
- the car navigation device 920 may include a plurality of antennas 937 as shown in FIG. FIG. 26 shows an example in which the car navigation apparatus 920 includes a plurality of antennas 937. However, the car navigation apparatus 920 may include a single antenna 937.
- the car navigation device 920 may include an antenna 937 for each wireless communication method.
- the antenna switch 936 may be omitted from the configuration of the car navigation device 920.
- the battery 938 supplies power to each block of the car navigation device 920 shown in FIG. 26 through a power supply line partially shown by broken lines in the drawing. Further, the battery 938 stores electric power supplied from the vehicle side.
- the information acquisition unit 241 and the communication processing unit 243 described with reference to FIG. 11 may be implemented in the wireless communication interface 933.
- at least some of these components may be implemented in the processor 921.
- the car navigation device 920 includes a module including a part (for example, the BB processor 934) or all of the wireless communication interface 933 and / or the processor 921, and the information acquisition unit 241 and the communication processing unit 243 are included in the module. May be implemented.
- the module executes a program for causing the processor to function as the information acquisition unit 241 and the communication processing unit 243 (in other words, a program for causing the processor to execute the operations of the information acquisition unit 241 and the communication processing unit 243). You may memorize
- a program for causing a processor to function as the information acquisition unit 241 and the communication processing unit 243 is installed in the car navigation device 920, and the wireless communication interface 933 (for example, the BB processor 934) and / or the processor 921 May be executed.
- the car navigation device 920 or the module may be provided as a device including the information acquisition unit 241 and the communication processing unit 243, and a program for causing the processor to function as the information acquisition unit 241 and the communication processing unit 243 is provided. May be provided.
- a readable recording medium in which the program is recorded may be provided.
- the wireless communication unit 220 described with reference to FIG. 11 may be implemented in the wireless communication interface 933 (for example, the RF circuit 935).
- the antenna unit 210 may be mounted on the antenna 937.
- an in-vehicle system (or vehicle) 940 including one or more blocks of the car navigation device 920 described above, an in-vehicle network 941, and a vehicle side module 942. That is, an in-vehicle system (or vehicle) 940 may be provided as a device including the information acquisition unit 241 and the communication processing unit 243.
- the vehicle-side module 942 generates vehicle-side data such as vehicle speed, engine speed, or failure information, and outputs the generated data to the in-vehicle network 941.
- the terminal device 200 acquires reference information for the base station 100 to select a codebook group, and transmits the acquired information to the base station 100 as a codebook indication. To do.
- the base station 100 can select a more suitable code book using the code book indication from the terminal device 200 as reference information.
- the base station 100 generates a reference signal generated by performing SCMA modulation on a sequence for each layer based on a code book as a reference signal for code book indication.
- SCMA-RS SCMA-RS
- the terminal device 200 can measure the channel information more accurately even in a situation where the signal level varies, such as SCMA. That is, according to the embodiment of the present disclosure, the terminal device 200 can perform a more appropriate codebook indication to the base station 100.
- the base station 100 uses the code book for generating whether the SCMA communication is performed or generating a 4-dimensional or 6-dimensional constellation with reference to the code book indication from the terminal device 200. Etc. can be determined.
- the base station 100 uses a plurality of code books that generate a more suitable constellation according to the state of the communication channel. It is possible to select from the candidates.
- processing steps in the processing of the present specification may not necessarily be executed in time series in the order described in the flowchart or the sequence diagram.
- processing steps in the processing may be executed in an order different from the order described as a flowchart or a sequence diagram, or may be executed in parallel.
- a processor for example, a CPU, a DSP, or the like included in a device (for example, a base station, a base station device, a module for a base station device, or a terminal device or a module for a terminal device) of this specification
- a computer program for functioning as a component of the device for example, an allocation unit, a selection unit, an information acquisition unit, a notification unit, and / or a communication processing unit
- the processor executes the operation of the component of the device
- a computer program can be created.
- a recording medium on which the computer program is recorded may be provided.
- An apparatus for example, a base station, a base station apparatus, a module for a base station apparatus, a terminal apparatus, or a device including a memory for storing the computer program and one or more processors capable of executing the computer program
- a module for a terminal device may also be provided.
- a method including the operation of the components of the device for example, an assignment unit, a selection unit, an information acquisition unit, a notification unit, and / or a communication processing unit is also included in the technology according to the present disclosure.
- An apparatus comprising: a control unit that causes a transmission unit to transmit information about a code book for multi-dimensionally modulating input data into a code word toward a base station.
- a control unit that causes a transmission unit to transmit information about a code book for multi-dimensionally modulating input data into a code word toward a base station.
- the apparatus according to (1) wherein the control unit acquires the information based on a reference signal transmitted from the base station.
- the said control part is an apparatus as described in said (2) which acquires the said information based on the said reference signal allocated and transmitted to several radio
- the control unit obtains the information from the reference signal assigned and transmitted to the plurality of radio resources based on a codeword demodulated based on a codebook assigned in advance, in (3) The device described.
- the sequence is multidimensionally modulated, and multiple elements included in the codeword generated for each codebook are multiplexed for each assigned radio resource.
- the transmission control unit assigns the reference signal corresponding to the radio resource stored in the storage unit to the plurality of radio resources.
- the apparatus according to (8) above. (10) The apparatus according to (9), wherein the codeword is generated by multi-dimensionally modulating the known sequence based on the codebook.
- the transmission control unit allocates each of the reference signals generated based on the codebooks included in different codebook groups to the radio resources included in different resource blocks, (9) or (10) The device described in 1.
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Abstract
Description
1.はじめに
1.1.SCMA
1.2.SCMAの適用例
1.3.CQIとリファレンス信号の一例
1.4.技術的課題
2.システムの概略的な構成
3.各装置の構成
3.1.基地局の構成
3.2.端末装置の構成
4.技術的特徴
5.処理の流れ
6.応用例
6.1.基地局に関する応用例
6.2.端末装置に関する応用例
7.まとめ
はじめに、図1~図8を参照して、SCMA、CQIとリファレンス信号の一例、及び技術的課題について説明する。
まず、図1~図4を参照して、SCMAを説明する。
図1は、SCMAについての概略的な処理の一例を説明するための説明図である。
図2は、コードブックに基づくコードワードの生成の例を説明するための説明図である。図2を参照すると、データ候補bi及びコードワードxjが示されている。コードブックの大きさ、即ち、データ候補biの数、及びコードワードxjの数が、それぞれMである。この場合に、例えば、入力情報であるデータは、ビットを要素として含むベクトルであり、log2Mの長さを有する。また、出力情報であるコードワードは、複素数を信号要素として含むベクトルであり、コードワードの送信に用いられる無線リソースの数Kと同じ長さを有する。したがって、コードブックは、入力情報及び出力情報がそれぞれベクトルである関数であるとも言える。出力情報であるコードワードは、レイヤ多重に適した所望の条件を満たすことが求められる。
図3は、コードブックの例を説明するための説明図である。図3を参照すると、コードブック1~6が示さている。コードブック1~6は、レイヤ1~6のためのコードブックである。このように、SCMAでは、レイヤごとにコードブックが用意される。この例では、入力情報であるデータは2ビットのデータであり、データ候補の数は4である。そのため、各コードブック内におけるコードワードの数も4である。各コードブック内のコードワードでは、4つの信号要素(即ち、複素数)のうちの2つが0であり、異なる2つのコードワードは互いに疎である。また、各コードブック内のコードワードでは、4つの信号要素のうちの2つが0ではない。即ち、4つの信号要素(換言すると、4次元のコンスタレーション)のうちの0ではない信号要素の数Nは、2である。
図4は、コードブックのリソースマッピングの例を説明するための説明図である。図4を参照すると、6つのレイヤと4つの無線リソースとが示されている。この例では、各レイヤのコードワード内の信号要素の数が4であるため、4つの無線リソースが用意される。例えば、各レイヤのコードワードに含まれる4つの信号要素のうちの、0ではない信号要素(即ち、2つの信号要素)が、対応する無線リソースにそれぞれマッピングされる。換言すると、図4に示す例では、4次元のコンスタレーションの信号が、2つの2次元のコンスタレーションに分割してマッピングされることとなる。具体的には、例えば、レイヤ1のコードワード内の1番目の信号要素は、無線リソース1にマッピングされ、レイヤ1のコードワード内の2番目の信号要素は、無線リソース2にマッピングされる。また、他の一例として、レイヤ3のコードワード内の1番目の信号要素は、無線リソース1にマッピングされ、レイヤ3のコードワード内の3番目の信号要素は、無線リソース3にマッピングされる。
SCMAでは、上述したように、送信側では、疎なコードワードの多重化が行われる。一方、受信側では、例えば、反復演算を用いたメッセージ伝達法(MPA:Message Passing Algorithm)と呼ばれる手法が用いられる。メッセージ伝達法によれば、例えば、受信装置は、4つの無線リソースの受信信号を参照し、当該受信信号の事後確率を最大にする入力ベクトルを推定する。
上記に説明したように、SCMAは、多重化の方法の非直交性により、マルチユーザー通信時において、ビームフォーミングを用いない場合においても、良好な特性を得られることが期待されている。
次に、図5~図7を参照して、LTEで使用されるCQI(Channel Quality Indicator)とリファレンス信号の一例とについて説明する。
まず、CQIについて説明する。LTEでは、基地局が適切な適応変調を行うために、端末装置から基地局に対してCQIが送信される。CQIは、4bitで示された16段階のCSI(Channel State Information)である。端末装置は、CQIにより、基地局に対して、変調方法(QPSK、16QAM、64QAMのいずれか)と、コーディングレート(0.08から0.93まで)とを指示できる。
次に、LTEで用いられるリファレンス信号の一例として、セル固有基準信号(CRS:Cell-specific Reference Signal)について説明する。例えば、図5は、CRSについて説明するための説明図であり、4アンテナによるMIMOをサポートするための、アンテナポート0から3までのリファレンス信号の一例を示している。
次に、LTEで用いられるリファレンス信号の一例として、チャネル状態情報参照信号(CSI-RS:Channel State Information Reference Signal)について説明する。
次に、LTEで用いられるリファレンス信号の一例として、復調基準信号(DM-RS:Demodulation Reference Signal)について説明する。
次に、本開示の実施形態に係る技術的課題を説明する。
続いて、図9を参照して、本開示の実施形態に係るシステム1の概略的な構成を説明する。図9は、本開示の一実施形態に係るシステム1の概略的な構成の一例を示す説明図である。図9に示すように、システム1は、基地局100と、端末装置200とを含む。なお、端末装置200は、複数含まれていてもよい。例えば、図9に示す例では、システム1は、端末装置200A~200Fを含んでいる。なお、以降の説明では、端末装置200A~200Fを特に区別しない場合には、単に「端末装置200」と称する場合がある。
基地局100は、移動体通信システム(又はセルラーシステム)の基地局である。基地局100は、セル101内に位置する端末装置(例えば、端末装置200)との無線通信を行う。例えば、基地局100は、端末装置へのダウンリンク信号を送信し、端末装置からのアップリンク信号を受信する。
端末装置200は、上記移動体通信システム(又はセルラーシステム)において通信可能な端末装置である。端末装置200は、基地局(例えば、基地局100)との無線通信を行う。例えば、端末装置200は、基地局からのダウンリンク信号を受信し、基地局へのアップリンク信号を送信する。
とりわけ本開示の実施形態では、コードブックを用いた非直交多重化/非直交多元接続が行われる。
続いて、図10及び図11を参照して、本開示の実施形態に係る基地局100及び端末装置200の構成の例を説明する。
まず、図10を参照して、本開示の実施形態に係る基地局100の構成の一例を説明する。図10は、本開示の実施形態に係る基地局100の構成の一例を示すブロック図である。図10に示すように、基地局100は、アンテナ部110、無線通信部120、ネットワーク通信部130、記憶部140、及び処理部150を備える。
アンテナ部110は、無線通信部120により出力される信号を電波として空間に放射する。また、アンテナ部110は、空間の電波を信号に変換し、当該信号を無線通信部120へ出力する。
無線通信部120は、信号を送受信する。例えば、無線通信部120は、端末装置へのダウンリンク信号を送信し、端末装置からのアップリンク信号を受信する。
ネットワーク通信部130は、情報を送受信する。例えば、ネットワーク通信部130は、他のノードへの情報を送信し、他のノードからの情報を受信する。例えば、上記他のノードは、他の基地局及びコアネットワークノードを含む。
記憶部140は、基地局100の動作のためのプログラム及び様々なデータを一時的に又は恒久的に記憶する。
処理部150は、基地局100の様々な機能を提供する。例えば、処理部150は、割当部151と、選択部153と、情報取得部155と、通知部157と、通信処理部159とを含む。なお、処理部150は、これらの構成要素以外の他の構成要素をさらに含み得る。即ち、処理部150は、これらの構成要素の動作以外の動作も行い得る。
次に、図11を参照して、本開示の実施形態に係る端末装置200の構成の一例を説明する。図11は、本開示の実施形態に係る端末装置200の構成の一例を示すブロック図である。図11に示すように、端末装置200は、アンテナ部210、無線通信部220、記憶部230及び処理部240を備える。
アンテナ部210は、無線通信部220により出力される信号を電波として空間に放射する。また、アンテナ部210は、空間の電波を信号に変換し、当該信号を無線通信部220へ出力する。
無線通信部220は、信号を送受信する。例えば、無線通信部220は、基地局からのダウンリンク信号を受信し、基地局へのアップリンク信号を送信する。
記憶部230は、端末装置200の動作のためのプログラム及び様々なデータを一時的に又は恒久的に記憶する。
処理部240は、端末装置200の様々な機能を提供する。例えば、処理部240は、情報取得部241と、通信処理部243とを含む。なお、処理部240は、これらの構成要素以外の他の構成要素をさらに含み得る。即ち、処理部240は、これらの構成要素の動作以外の動作も行い得る。
次に、図12~図21を参照して、本開示の一実施形態に係る技術的特徴について説明する。
例えば、基地局100(通信処理部159)は、端末装置200に対して、コードブックグループを選択するためのインディケーション(以降では、「コードブックインディケーション」と称する場合がある)をリクエストする。また、基地局100(通信処理部159)は、コードブックインディケーションのリクエストに次いで、当該端末装置200に対してコードブックインディケーションのためのリファレンス信号を送信してもよい。そして、基地局100(通信処理部159)は、上記リクエスト(もしくは、上記リファレンス信号)に対する応答として、端末装置200からコードブックインディケーションを受信する。
SCMAを利用した通信を行う各端末は、SCMAにおける変調が施されたデータを復調するにあたり、多重された他の信号を妨害波として除去するため、自らのレイヤのコードブックだけでなく、同時に多重される他のレイヤのコードブックを保持する。
次に、コードブックインディケーションのために使用されるリファレンス信号の一例について説明する。例えば、図12は、本開示の一実施形態に係るリファレンス信号の一例について説明するための説明図である。なお、以降の説明では、コードブックインディケーションを端末装置200に送信させるためのリファレンス信号を、他のリファレンス信号と区別するために「SCMA-RS」と称する場合がある。また、本説明では、SCMAを利用した通信において、図4に示すように、6つのレイヤそれぞれについて生成されたコードワードの各信号要素を、4つの無線リソースにマッピングする場合を例に説明する。
(c-1)基地局100の動作
例えば、基地局100(通信処理部159)は、端末装置200に対して、コードブックインディケーションのリクエストを送信する。このとき、基地局100(通信処理部159)は、SCMA-RSの送信に使用するリソースブロックを端末装置200に通知する。
例えば、端末装置200(通信処理部243)は、基地局100からコードブックインディケーションのリクエストを受信する。また、端末装置200(通信処理部243)は、当該リクエストに続いて送信されるSCMA-RSを、当該リクエストに基づき取得してもよい。この場合には、端末装置200(通信処理部243)は、コードブックインディケーションのリクエストに基づき基地局100から通知されたリソースブロックを参照し、当該基地局100から送信されたSMCA-RSを取り出す。
例えば、基地局100(通信処理部159)は、端末装置200へのコードブックインディケーションのリクエストの送信後(または、上記リファレンス信号の送信後)に、当該端末装置200からコードブックインディケーションを受信する。このとき、基地局100(通信処理部159)は、端末装置200から複数のコードブックグループについて、コードブックインディケーションを受信してもよい。
例えば、端末装置200(通信処理部243)は、上記複数のコードブックグループのうちの、基地局100から通知された、各レイヤに対応するコードブックグループに基づいて、各レイヤに対応するコードワードを分離し、当該コードワードから受信データを復調する。なお、端末装置200(通信処理部243)による、受信データの復調に係る動作の詳細については、受信処理の一連の流れとあわせて別途後述する。
前述した例では、SCMA-RSの生成に既知のシーケンスを使用する例について説明した。一方で、端末装置200が、当該SCMA-RSから分離される各レイヤに対応する信号に対して、あらかじめ決められた評価を実行することが可能であれば、当該シーケンスとして使用されるデータの内容は特に限定されない。そこで、本項では、SCMA-RSの生成に使用されるシーケンスの一例について説明する。
(a)リソースの割当て
例えば、基地局100(割当部151)は、端末装置200に無線リソースを割り当てる。
例えば、基地局100(割当部151)は、コードブックを用いた非直交多重化の対象となる複数のレイヤの各々を端末装置200に割り当てる。
上述したように、例えば、上記コードブックは、SC(Sparse Code)のコードブックであり、上記コードブックを用いた上記非直交多重化は、SCMAの多重化である。
例えば、上記複数のレイヤは、SCMAのレイヤである。
例えば、基地局100(割当部151)は、上記複数のレイヤの各々を異なる端末装置200に割り当てる。一例として、基地局100(割当部151)は、レイヤ1を端末装置200Aに割り当て、レイヤ2を端末装置200Bに割り当て、レイヤ3を端末装置200Cに割り当て、レイヤ4を端末装置200Dに割り当て、レイヤ5を端末装置200Eに割り当て、レイヤ6を端末装置200Fに割り当てる。これにより、例えば、より多くの端末装置200が同時に通信することが可能になる。
基地局100(情報取得部155)は、上記複数のレイヤ(即ち、コードブックを用いた非直交多重化の対象となる複数のレイヤ)のうちの、端末装置200に割り当てられるレイヤを示す情報を取得する。そして、基地局100(通知部157)は、上記レイヤを端末装置200に通知する。
例えば、基地局100(通知部157)は、ダウンリンク制御情報(Downlink Control Information:DCI)の中で、上記レイヤを端末装置200に通知する。例えば、当該DCIは、物理ダウンリンク制御チャネル(Physical Downlink Control Channel:PDCCH)上で送信される情報である。
例えば、基地局100(通知部157)は、上記レイヤを示す情報を含むDCIを生成する。上記レイヤを示す当該情報は、上記レイヤのレイヤ番号であってもよい。
例えば、基地局100(通知部157)は、上記DCIの中で、上記レイヤのコードワードの送信に使用される無線リソースを端末装置200に通知する。これにより、例えば、端末装置200は、どの無線リソースについてのレイヤが端末装置200に割り当てられたかを知ることが可能になる。
例えば、基地局100(通信処理部159)は、上記複数のレイヤ(即ち、コードブックを用いた非直交多重化の対象となる複数のレイヤ)についての通信処理を行う。
例えば、上記非直交多重化は、ダウンリンクについて行われる。この場合に、基地局100(通信処理部159)は、上記複数のレイヤについての送信処理を行う。一方、端末装置200(通信処理部243)は、上記複数のレイヤのうちの、端末装置200に割り当てられる上記レイヤについての受信処理を行う。
-コードワードの生成
例えば、上記送信処理は、上記複数のレイヤの各々について、レイヤのデータから当該レイヤのコードワードを生成することを含む。例えば、基地局100(通信処理部159)は、上記複数のレイヤの各々について、レイヤのためのコードブックに基づいて、当該レイヤのデータから当該レイヤのコードワードを生成する。
例えば、上記送信処理は、上記複数のレイヤの各々について、上記コードワードの送信に使用される無線リソースに上記コードワードをマッピングすることを含む。
--第1の例
図18は、基地局100の送信処理全体の第1の例を説明するための説明図である。例えば、基地局100の送信処理は、符号化、レイヤマッピング、コードワードに基づくコードワードの生成、リソースマッピング及びIFFT(Inverse Fast Fourier Transform)などを含む。
図19は、基地局100の送信処理全体の第2の例を説明するための説明図である。当該第2の例は、MIMO(Multiple-Input and Multiple-Output)のケースの例である。なお、本説明では、MIMOのケースの例として、空間多重化のために、プリコーダによるビームフォーミングを伴う場合について説明する。
-無線リソースからの受信信号のデマッピング
例えば、上記受信処理は、端末装置200に割り当てられた無線リソースから、受信信号をデマッピングすることを含む。
例えば、上記受信処理は、SICにより、SCMA変調された各レイヤのデータを復調することを含む。例えば、端末装置200(通信処理部243)は、上記各レイヤのためのコードブックに基づいて、上記各レイヤの上記データを復調する。
また、上記受信処理は、SICにより、SCMA-RSを復号することで、SCMAのチャンネル評価に用いるデータ(即ち、各レイヤに対応するシーケンス)を復調することを含む。
--第1の例
図20は、端末装置200の受信処理全体の第1の例を説明するための説明図である。例えば、端末装置200の受信処理は、FFT(Fast Fourier Transform)、リソースデマッピング、SCMA復調、レイヤマッピング、及び復号化などを含む。
図21は、端末装置200の受信処理全体の第2の例を説明するための説明図である。当該第2の例は、MIMOのケースの例である。図21に示されるように、この例では、端末装置200の受信処理は、SCMA変調されたデータの復号結果から各レイヤのデータを取り出す第1のレイヤデマッピングに加えて、空間多重化された各信号を取り出すための第2のレイヤデマッピングを含む。
上記非直交多重化は、アップリンクについて行われてもよい。この場合に、端末装置200(通信処理部243)は、上記複数のレイヤのうちの、端末装置200に割り当てられる上記レイヤについての送信処理を行ってもよい。一方、基地局100(通信処理部159)は、上記複数のレイヤについての受信処理を行ってもよい。
-コードワードの生成
上記送信処理は、端末装置200に割り当てられるレイヤのデータから当該レイヤのコードワードを生成することを含んでもよい。端末装置200(通信処理部243)は、上記レイヤのためのコードブックに基づいて、上記レイヤのデータから上記レイヤのコードワードを生成してもよい。
例えば、上記送信処理は、端末装置200に割り当てられる上記レイヤの上記コードワードの送信に使用される無線リソース(即ち、端末装置200に割り当てられる無線リソース)に、上記レイヤの上記コードワードをマッピングすることを含んでもよい。
上記受信処理は、SICにより、上記複数のレイヤの各々のデータを順次復号することを含んでもよい。基地局100(通信処理部159)は、上記複数のレイヤのコードブックに基づいて、上記複数のレイヤの各々のデータを順次復号してもよい。
続いて、図22を参照して、本開示の一実施形態に係る処理の一例を説明する。なお、本説明では、コードブックインディケーションに関する処理に着目して説明する。例えば、図22は、本開示の一実施形態に係る処理の概略的な流れの一例を示したシーケンス図である。図22に示す例は、SCMA-RSを利用したコードブックインディケーションに関する処理の一例を示している。
基地局100は、端末装置200に対して、コードブックグループを選択するためのインディケーション(即ち、コードブックインディケーション)をリクエストする。このとき、基地局100は、SCMA-RSの送信に使用するリソースブロックを端末装置200に通知する。
次いで、基地局100は、端末装置200に対して、端末装置200に対してコードブックインディケーションのためのリファレンス信号(即ち、SCMA-RS)を送信する。なお、このとき基地局100は、割り当てられたサブフレームまたは周波数帯が互いに異なる複数のリソースブロックを使用することで、複数組のSCMA-RSを端末装置200に送信してもよい。
端末装置200は、基地局100からコードブックインディケーションのリクエストを受信すると、当該リクエストに基づき、続いて送信されるSCMA-RSを取得する。具体的には、端末装置200は、コードブックインディケーションのリクエストに基づき基地局100から通知されたリソースブロックを参照し、当該基地局100から送信されたSMCA-RSを取り出す。
そして、端末装置200は、取得した情報をコードブックインディケーションとして基地局100に送信する。これにより、基地局100は、端末装置200から受信したコードブックインディケーションを参考情報として、より好適なコードブックグループを選択することが可能となる。
本開示に係る技術は、様々な製品へ応用可能である。例えば、基地局100は、マクロeNB又はスモールeNBなどのいずれかの種類のeNB(evolved Node B)として実現されてもよい。スモールeNBは、ピコeNB、マイクロeNB又はホーム(フェムト)eNBなどの、マクロセルよりも小さいセルをカバーするeNBであってよい。その代わりに、基地局100は、NodeB又はBTS(Base Transceiver Station)などの他の種類の基地局として実現されてもよい。基地局100は、無線通信を制御する本体(基地局装置ともいう)と、本体とは別の場所に配置される1つ以上のRRH(Remote Radio Head)とを含んでもよい。また、後述する様々な種類の端末が一時的に又は半永続的に基地局機能を実行することにより、基地局100として動作してもよい。さらに、基地局100の少なくとも一部の構成要素は、基地局装置又は基地局装置のためのモジュールにおいて実現されてもよい。
(第1の応用例)
図23は、本開示に係る技術が適用され得るeNBの概略的な構成の第1の例を示すブロック図である。eNB800は、1つ以上のアンテナ810、及び基地局装置820を有する。各アンテナ810及び基地局装置820は、RFケーブルを介して互いに接続され得る。
図24は、本開示に係る技術が適用され得るeNBの概略的な構成の第2の例を示すブロック図である。eNB830は、1つ以上のアンテナ840、基地局装置850、及びRRH860を有する。各アンテナ840及びRRH860は、RFケーブルを介して互いに接続され得る。また、基地局装置850及びRRH860は、光ファイバケーブルなどの高速回線で互いに接続され得る。
(第1の応用例)
図25は、本開示に係る技術が適用され得るスマートフォン900の概略的な構成の一例を示すブロック図である。スマートフォン900は、プロセッサ901、メモリ902、ストレージ903、外部接続インタフェース904、カメラ906、センサ907、マイクロフォン908、入力デバイス909、表示デバイス910、スピーカ911、無線通信インタフェース912、1つ以上のアンテナスイッチ915、1つ以上のアンテナ916、バス917、バッテリー918及び補助コントローラ919を備える。
図26は、本開示に係る技術が適用され得るカーナビゲーション装置920の概略的な構成の一例を示すブロック図である。カーナビゲーション装置920は、プロセッサ921、メモリ922、GPS(Global Positioning System)モジュール924、センサ925、データインタフェース926、コンテンツプレーヤ927、記憶媒体インタフェース928、入力デバイス929、表示デバイス930、スピーカ931、無線通信インタフェース933、1つ以上のアンテナスイッチ936、1つ以上のアンテナ937及びバッテリー938を備える。
以上、図9~図26を参照して、本開示の実施形態に係る装置及び処理を説明した。
(1)
入力データをコードワードに多次元変調するためのコードブックについての情報を、基地局に向けて送信部に送信させる制御部
を備える、装置。
(2)
前記制御部は、前記基地局から送信されたリファレンス信号に基づき、前記情報を取得する、前記(1)に記載の装置。
(3)
前記制御部は、複数の無線リソースに割り当てられて送信された前記リファレンス信号に基づき、前記情報を取得する、前記(2)に記載の装置。
(4)
前記制御部は、前記複数の無線リソースに割り当てられて送信された前記リファレンス信号から、あらかじめ割り当てられたコードブックを基に復調されたコードワードに基づき、前記情報を取得する、前記(3)に記載の装置。
(5)
前記制御部は、前記リファレンス信号について測定された信号対雑音比を示す情報を、前記基地局に向けて前記送信部に送信させる、前記(2)~(4)のいずれか一項に記載の装置。
(6)
入力データをコードワードに多次元変調するためのコードブックについての情報を端末から取得する取得部と、
前記情報を取得した後に、前記コードブックを選択する選択部と、
を備える、装置。
(7)
前記選択部は、取得された前記情報に基づいて、前記コードブックを選択する、前記(6)に記載の装置。
(8)
送信部に、前記端末が前記情報を取得するためのリファレンス信号を、当該端末に向けて送信させる送信制御部を備える、前記(6)または(7)に記載の装置。
(9)
互いに異なる複数のコードブックに基づき、シーケンスが多次元変調されて、当該コードブックごとに生成されたコードワードに含まれる複数の要素を、割り当て先となる無線リソースごとに多重化することで生成された前記リファレンス信号を記憶する記憶部を備え、
前記送信制御部は、複数の前記無線リソースに、前記記憶部に記憶された、当該無線リソースに対応する前記リファレンス信号を割り当てる、
前記(8)に記載の装置。
(10)
前記コードワードは、既知の前記シーケンスが、前記コードブックに基づき多次元変調されることで生成される、前記(9)に記載の装置。
(11)
前記送信制御部は、互いに異なるコードブックグループに含まれる前記コードブックに基づき生成された前記リファレンス信号のそれぞれを、互いに異なるリソースブロックに含まれる前記無線リソースに割り当てる、前記(9)または(10)に記載の装置。
(12)
前記互いに異なるリソースブロックは、互いに異なる周波数帯に割り当てられたリソースブロックである、前記(11)に記載の装置。
(13)
前記互いに異なるリソースブロックは、互いに異なるサブフレームに割り当てられたリソースブロックである、前記(11)に記載の装置。
(14)
前記シーケンスの初期値は、当該シーケンスを前記コードワードに変換するための前記コードブックの識別情報を含む、前記(9)に記載の装置。
(15)
前記シーケンスの初期値は、当該シーケンスを前記コードワードに変換するための前記コードブックが含まれるコードブックグループの識別情報を含む、前記(9)に記載の装置。
(16)
プロセッサが、
入力データをコードワードに多次元変調するためのコードブックについての情報を、基地局に向けて送信部に送信させること
を含む、方法。
(17)
プロセッサが、
入力データをコードワードに多次元変調するためのコードブックについての情報を端末から取得することと、
前記情報を取得した後に、前記コードブックを選択することと、
を含む、方法。
(18)
コンピュータに、
入力データをコードワードに多次元変調するためのコードブックについての情報を、基地局に向けて送信部に送信させること
を実行させる、プログラム。
(19)
コンピュータに、
入力データをコードワードに多次元変調するためのコードブックについての情報を端末から取得することと、
前記情報を取得した後に、前記コードブックを選択することと、
を実行させる、プログラム。
100 基地局
101 セル
110 アンテナ部
120 無線通信部
130 ネットワーク通信部
140 記憶部
150 処理部
151 割当部
153 選択部
155 情報取得部
157 通知部
159 通信処理部
200 端末装置
210 アンテナ部
220 無線通信部
230 記憶部
240 処理部
241 情報取得部
243 通信処理部
Claims (19)
- 無線通信を行う通信部と、
入力データをコードワードに多次元変調するためのコードブックについての情報が、前記通信部から基地局に送信されるように制御する制御部と、
を備える、装置。 - 前記制御部は、前記基地局から送信されたリファレンス信号に基づき、前記情報を取得する、請求項1に記載の装置。
- 前記制御部は、複数の無線リソースに割り当てられて送信された前記リファレンス信号に基づき、前記情報を取得する、請求項2に記載の装置。
- 前記制御部は、前記複数の無線リソースに割り当てられて送信された前記リファレンス信号から、あらかじめ割り当てられたコードブックを基に復調されたコードワードに基づき、前記情報を取得する、請求項3に記載の装置。
- 前記制御部は、前記リファレンス信号について測定された信号対雑音比を示す情報が、前記通信部から前記基地局に送信されるように制御する、請求項2に記載の装置。
- 入力データをコードワードに多次元変調するためのコードブックについての情報を端末から取得する取得部と、
前記情報を取得した後に、前記コードブックを選択する選択部と、
を備える、装置。 - 前記選択部は、取得された前記情報に基づいて、前記コードブックを選択する、請求項6に記載の装置。
- 送信部に、前記端末が前記情報を取得するためのリファレンス信号を、当該端末に向けて送信させる送信制御部を備える、請求項6に記載の装置。
- 互いに異なる複数のコードブックに基づき、シーケンスが多次元変調されて、当該コードブックごとに生成されたコードワードに含まれる複数の要素を、割り当て先となる無線リソースごとに多重化することで生成された前記リファレンス信号を記憶する記憶部を備え、
前記送信制御部は、複数の前記無線リソースに、前記記憶部に記憶された、当該無線リソースに対応する前記リファレンス信号を割り当てる、
請求項8に記載の装置。 - 前記コードワードは、既知の前記シーケンスが、前記コードブックに基づき多次元変調されることで生成される、請求項9に記載の装置。
- 前記送信制御部は、互いに異なるコードブックグループに含まれる前記コードブックに基づき生成された前記リファレンス信号のそれぞれを、互いに異なるリソースブロックに含まれる前記無線リソースに割り当てる、請求項9に記載の装置。
- 前記互いに異なるリソースブロックは、互いに異なる周波数帯に割り当てられたリソースブロックである、請求項11に記載の装置。
- 前記互いに異なるリソースブロックは、互いに異なるサブフレームに割り当てられたリソースブロックである、請求項11に記載の装置。
- 前記シーケンスの初期値は、当該シーケンスを前記コードワードに変換するための前記コードブックの識別情報を含む、請求項9に記載の装置。
- 前記シーケンスの初期値は、当該シーケンスを前記コードワードに変換するための前記コードブックが含まれるコードブックグループの識別情報を含む、請求項9に記載の装置。
- 無線通信を行うことと、
プロセッサが、入力データをコードワードに多次元変調するためのコードブックについての情報が、基地局に送信されるように制御することと、
を含む、方法。 - プロセッサが、
入力データをコードワードに多次元変調するためのコードブックについての情報を端末から取得することと、
前記情報を取得した後に、前記コードブックを選択することと、
を含む、方法。 - コンピュータに、
無線通信を行うことと、
入力データをコードワードに多次元変調するためのコードブックについての情報が、基地局に送信されるように制御することと、
を実行させる、プログラム。 - コンピュータに、
入力データをコードワードに多次元変調するためのコードブックについての情報を端末から取得することと、
前記情報を取得した後に、前記コードブックを選択することと、
を実行させる、プログラム。
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US10110286B2 (en) * | 2015-03-30 | 2018-10-23 | Samsung Electronics Co., Ltd. | Method and apparatus for codebook design and signaling |
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KR102378790B1 (ko) * | 2015-07-31 | 2022-03-28 | 삼성전자주식회사 | 다중 사용자 접속을 지원하는 통신시스템에서 신호를 송신하기 위한 방법 및 장치 |
EP3328149B1 (en) * | 2015-08-28 | 2019-11-27 | Huawei Technologies Co., Ltd. | Method and device for uplink transmission in random access process |
US10624039B2 (en) * | 2015-08-28 | 2020-04-14 | Huawei Technologies Co., Ltd. | System and method for power offset adjustments for downlink communications |
US11917634B2 (en) * | 2018-12-17 | 2024-02-27 | Interdigital Patent Holdings, Inc. | Signal design associated with concurrent delivery of energy and information |
TWI807941B (zh) * | 2022-07-28 | 2023-07-01 | 國立成功大學 | 基於人工智慧算法之下行稀疏碼多址接入系統資源分配方法 |
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US20140140360A1 (en) * | 2012-11-16 | 2014-05-22 | Futurewei Technologies, Inc. | Systems and Methods for Sparse Code Multiple Access |
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US20140140360A1 (en) * | 2012-11-16 | 2014-05-22 | Futurewei Technologies, Inc. | Systems and Methods for Sparse Code Multiple Access |
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