JP7619655B2 - Terminal and communication method - Google Patents

Description

The present invention relates to a terminal and a communication method in a wireless communication system.

For NR (New Radio) (also known as "5G"), the successor system to LTE (Long Term Evolution), technologies are being considered that meet the requirements of a large-capacity system, high data transmission speed, low latency, simultaneous connection of a large number of terminals, low cost, and low power consumption (for example, non-patent document 1).

In NR Release 17, the use of higher frequency bands than in previous releases (e.g., Non-Patent Document 2) is being considered. For example, applicable numerology including subcarrier spacing, channel bandwidth, etc., physical layer design, and actual wireless communication obstacles in the frequency band from 52.6 GHz to 71 GHz are being considered.

3GPP TS 38.300 V16.2.0 (2020-07) 3GPP TS 38.306 V16.1.0 (2020-07)

In conventional DMRS (Demodulation reference signal) designs, if the symbol in which the DMRS is placed is subjected to strong interference, detection of all DMRS may fail, resulting in a significant deterioration in communication quality.

The present invention has been made in consideration of the above points, and makes it possible to use a reference signal in a wireless communication system that improves communication quality and reduces overhead.

According to the disclosed technology, there is provided a terminal having a receiving unit that receives settings related to a reference signal from a base station, a control unit that places a first reference signal based on the settings and data in resources, and a transmitting unit that transmits the resources to the base station, wherein the control unit places the first reference signal in all frequency domains of the resources with different frequency domain arrangements for consecutive first symbols and second symbols included in the resources, the comb pattern is a type in which the first reference signal is arranged on every other subcarrier or a type in which the first reference signal is arranged on every third subcarrier, and the control unit applies TD-OCC (Time Division Orthogonal Cover Code) to the first symbols and the second symbols .

According to the disclosed technology, a reference signal can be used in a wireless communication system to improve communication quality and reduce overhead.

1 is a diagram illustrating an example of a configuration of a wireless communication system according to an embodiment of the present invention. A diagram showing an example of DMRS placement (1). A diagram showing an example of DMRS placement (2). A diagram showing an example of DMRS placement (3). A figure showing an example of DMRS placement (4). FIG. 1 is a diagram for explaining a coherent bandwidth. FIG. 1 is a diagram showing an example (1) of DMRS placement in an embodiment of the present invention. A figure showing an example (2) of DMRS placement in an embodiment of the present invention. A figure showing an example (3) of DMRS placement in an embodiment of the present invention. A figure showing an example (4) of DMRS placement in an embodiment of the present invention. A figure showing an example (5) of DMRS placement in an embodiment of the present invention. A figure showing an example (6) of DMRS placement in an embodiment of the present invention. A figure showing an example (7) of DMRS placement in an embodiment of the present invention. A figure showing an example (8) of DMRS placement in an embodiment of the present invention. FIG. 2 is a diagram illustrating an example of a functional configuration of a base station 10 according to an embodiment of the present invention. FIG. 2 is a diagram illustrating an example of a functional configuration of a terminal 20 according to an embodiment of the present invention. 2 is a diagram illustrating an example of a hardware configuration of a base station 10 or a terminal 20 according to an embodiment of the present invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the embodiment described below is an example, and the embodiment to which the present invention is applicable is not limited to the following embodiment.

Existing technology is used as appropriate in the operation of the wireless communication system of the embodiment of the present invention. However, the existing technology is, for example, the existing LTE, but is not limited to the existing LTE. Furthermore, the term "LTE" used in this specification has a broad meaning including LTE-Advanced and systems subsequent to LTE-Advanced (e.g., NR) unless otherwise specified.

In addition, in the embodiment of the present invention described below, terms such as SS (Synchronization signal), PSS (Primary SS), SSS (Secondary SS), PBCH (Physical broadcast channel), PRACH (Physical random access channel), PDCCH (Physical Downlink Control Channel), PDSCH (Physical Downlink Shared Channel), PUCCH (Physical Uplink Control Channel), and PUSCH (Physical Uplink Shared Channel) used in existing LTE are used. This is for convenience of description, and similar signals, functions, etc. may be called by other names. In addition, the above-mentioned terms in NR correspond to NR-SS, NR-PSS, NR-SSS, NR-PBCH, NR-PRACH, etc. However, even if a signal is used in NR, it is not necessarily specified as "NR-".

In addition, in an embodiment of the present invention, the duplex method may be a TDD (Time Division Duplex) method, an FDD (Frequency Division Duplex) method, or another method (e.g., Flexible Duplex, etc.).

In addition, in an embodiment of the present invention, when radio parameters, etc. are "configured," this may mean that predetermined values are pre-configured, or that radio parameters notified from the base station 10 or the terminal 20 are configured.

Figure 1 is a diagram showing an example of the configuration of a wireless communication system in an embodiment of the present invention. As shown in Figure 1, the wireless communication system in the embodiment of the present invention includes a base station 10 and a terminal 20. Although Figure 1 shows one base station 10 and one terminal 20, this is an example and there may be multiple of each.

The base station 10 is a communication device that provides one or more cells and performs wireless communication with the terminal 20. The physical resources of a wireless signal are defined in the time domain and the frequency domain, and the time domain may be defined by the number of OFDM (Orthogonal Frequency Division Multiplexing) symbols, and the frequency domain may be defined by the number of subcarriers or the number of resource blocks. The base station 10 transmits a synchronization signal and system information to the terminal 20. The synchronization signal is, for example, NR-PSS and NR-SSS. The system information is, for example, transmitted by NR-PBCH and is also called broadcast information. The synchronization signal and system information may be called SSB (SS/PBCH block). As shown in FIG. 1, the base station 10 transmits a control signal or data to the terminal 20 in DL (Downlink) and receives a control signal or data from the terminal 20 in UL (Uplink). Both the base station 10 and the terminal 20 can transmit and receive signals by performing beamforming. In addition, both the base station 10 and the terminal 20 can apply communication by MIMO (Multiple Input Multiple Output) to DL or UL. In addition, both the base station 10 and the terminal 20 may communicate via a secondary cell (SCell: Secondary Cell) and a primary cell (PCell: Primary Cell) by CA (Carrier Aggregation). Furthermore, the terminal 20 may communicate via a primary cell of the base station 10 and a primary secondary cell (PSCell: Primary Secondary Cell) of another base station 10 by DC (Dual Connectivity).

The terminal 20 is a communication device equipped with a wireless communication function, such as a smartphone, a mobile phone, a tablet, a wearable terminal, or a communication module for M2M (Machine-to-Machine). As shown in FIG. 1, the terminal 20 receives control signals or data from the base station 10 in DL and transmits control signals or data to the base station 10 in UL, thereby utilizing various communication services provided by the wireless communication system. The terminal 20 also receives various reference signals transmitted from the base station 10, and performs measurement of the propagation path quality based on the reception results of the reference signals.

Here, in NR Release 17, the use of higher frequency bands than before is being considered. For example, the applicability of waveforms, numerology, channel access mechanisms, etc., the impact on physical layer design, and interference in actual wireless communications are being considered. Furthermore, for example, a channel access mechanism that takes into account interference with other nodes assuming beam operation to satisfy regulations applicable to unlicensed bands is being verified.

In addition, NR Release 17 considers the following items 1)-3), for example.

1) Numerology: Considerations are being made regarding the new numerology, including BWP (Bandwidth Part), beam switching time, HARQ (Hybrid automatic repeat request) scheduling, UE processing time, and preparation and calculation time for PDSCH, PUSCH/SRS, CSI, etc.

2) For the frequency bands targeted for beam operation, beams compatible with up to 64 SSB (SS/PBCH block) for licensed bands and proposed licensed bands, and channel access mechanisms assuming beam operation are being considered.

3) Channelization and RF Requirements Band definition, RF requirements, and Radio resource management (RRM)/Radio link monitoring (RLM) requirements are being considered.

In the current NR, the following two types of DMRS with different multiplexing methods are supported. Figure 2 is a diagram showing an example of DMRS placement (1). Like the front-loaded DMRS shown in Figure 2, the type 1 multiplexing method is two comb-type frequency multiplexing, two cyclic shifts, and TD-OCC (Time Division Orthogonal Cover Code). Type 1 DMRS supports up to four layers when placed in one symbol, and up to eight layers when placed in two symbols. The density in the frequency domain is six subcarriers per port. In addition, in the matrices shown in Figures 2 and 3 onwards, the horizontal axis corresponds to the symbol and the vertical axis corresponds to the subcarrier.

Figure 3 is a diagram showing an example of DMRS placement (2). Like the forward placement DMRS shown in Figure 3, the type 2 multiplexing method is FD-OCC (Frequency Division Orthogonal Cover Code), TD-OCC, and FDM (Frequency division multiplexing). Type 2 DMRS supports up to 6 layers when placed in one symbol, and up to 12 layers when placed in two symbols. The density in the frequency domain is 4 subcarriers per port.

Figure 4 is a diagram showing an example of DMRS arrangement (3). As shown in Figure 4, in addition to the forward-arranged DMRS in the third symbol, one additional DMRS may be arranged in the 12th symbol.

Figure 5 is a diagram showing an example of DMRS arrangement (4). As shown in Figure 5, in addition to the forward-arranged DMRS in the third symbol, additional DMRS may be arranged in the sixth, ninth, and twelfth symbols, for a total of three symbols.

Figure 6 is a diagram for explaining the coherent bandwidth. For scenarios in high frequency bands, it is being considered to expand the subcarrier spacing in consideration of the coherent bandwidth shown in Figure 6. Figure 6 plots the 50% correlated coherent bandwidth and the 90% correlated coherent bandwidth, and the RMS-DS (root mean square delay spread). The coherent bandwidth indicates a bandwidth in which the channel characteristics can be assumed to be constant. As the subcarrier spacing increases, the number of subcarriers included in one coherent bandwidth decreases. In that case, the channel characteristics may differ significantly even between two adjacent subcarriers. Due to the channel characteristic difference, the performance of FD-OCC may be significantly degraded. Therefore, a high-density DMRS is required in the frequency domain.

Here, as a design of the NR DMRS, the DMRS ports may be concatenated or multiplexed. Also, for example, a DMRS having a new structure that is distributed over the entire frequency domain may be defined. Also, for example, a different comb pattern may be defined for the additional DMRS.

On the other hand, if the symbol in which the DMRS is placed is subject to strong interference, it may fail to detect all DMRS, and communication quality may deteriorate significantly. Therefore, for forward-placed DMRS with a length of two symbols, placement may be supported in which different comb patterns are used for different symbols.

Figure 7 is a diagram showing an example (1) of DMRS arrangement in an embodiment of the present invention. As shown in Figure 7, by arranging DMRS port #0 and DMRS port #1 by frequency multiplexing, it is possible to arrange DMRS in all frequency domains across multiple symbols for each port. In the comb pattern of DMRS port #0, DMRS is arranged on every other subcarrier in a certain symbol, and DMRS is not arranged on the same subcarrier in the first symbol and the second symbol. The comb pattern of DMRS port #1 is obtained by replacing the first symbol and the second symbol of DMRS port #0. For example, the arrangement of DMRS shown in Figure 7 may be called "configuration type 1". The arrangement of DMRS shown in Figure 7 provides a diversity effect in the time domain compared to the case where DMRS is arranged in all frequency domains of a single symbol.

OCC does not have to be applied to the DMRS 2-port arrangement shown in Figure 7. Although the number of ports is reduced in the DMRS arrangement shown in Figure 7 compared to the case where OCC is applied, no problem occurs because the beam is relatively narrow in the high frequency band, the SDM (Space division multiplexing) capacity is small, and the number of UEs in the beam direction is small. The DMRS arrangement shown in Figure 7 can improve the density of DMRS in the frequency domain using the same number of resource elements as the Release 16 2-symbol DMRS.

Figure 8 is a diagram showing an example of DMRS arrangement (2) in an embodiment of the present invention. Figure 8 shows another example of DMRS arrangement different from that of Figure 7. As shown in Figure 8, by arranging DMRS port #0 and DMRS port #1 by frequency multiplexing, it is possible to arrange DMRS in all frequency domains across multiple symbols for each port. In the comb pattern of DMRS port #0, DMRS with a width of 2 subcarriers is arranged every 2 subcarriers in a certain symbol, and DMRS is not arranged in the same subcarrier in the first symbol and the second symbol. The comb pattern of DMRS port #1 is obtained by replacing the first symbol and the second symbol of DMRS port #0. For example, the DMRS arrangement shown in Figure 8 may be called "configuration type 2".

Figure 9 is a diagram showing an example (3) of DMRS placement in an embodiment of the present invention. Figure 10 is a diagram showing an example (4) of DMRS placement in an embodiment of the present invention. Figures 9 and 10 are examples in which TD-OCC is applied to the DMRS 2-port placement shown in Figure 7 to create DMRS 4-ports.

As shown in Figure 9, in the arrangement of DMRS port #0 shown in Figure 7, the first symbol multiplied by +1 and the second symbol multiplied by +1 is port #0, and the first symbol multiplied by +1 and the second symbol multiplied by -1 is port #1, which is DMRS CDM group #0.

As shown in Figure 10, in the arrangement of DMRS port #1 shown in Figure 7, the first symbol multiplied by +1 and the second symbol multiplied by +1 is port #2, and the first symbol multiplied by +1 and the second symbol multiplied by -1 is port #3, which are DMRS CDM group #1.

By arranging DMRS as shown in Figures 9 and 10, the SDM capacity or the number of UEs multiplexed can be increased.

Figure 11 is a diagram showing an example (5) of DMRS placement in an embodiment of the present invention. Figure 12 is a diagram showing an example (6) of DMRS placement in an embodiment of the present invention. Figures 11 and 12 are examples in which TD-OCC is applied to the DMRS 2 port placement shown in Figure 8 to create a DMRS 4 port arrangement.

As shown in Figure 11, in the arrangement of DMRS port #0 shown in Figure 8, the first symbol multiplied by +1 and the second symbol multiplied by +1 is port #0, and the first symbol multiplied by +1 and the second symbol multiplied by -1 is port #1, which is DMRS CDM group #0.

As shown in Figure 12, in the arrangement of DMRS port #1 shown in Figure 8, the first symbol multiplied by +1 and the second symbol multiplied by +1 is port #2, and the first symbol multiplied by +1 and the second symbol multiplied by -1 is port #3, which are DMRS CDM group #1.

By arranging DMRS as shown in Figures 11 and 12, the SDM capacity or the number of UEs multiplexed can be increased.

Figure 13 is a diagram showing an example (7) of DMRS placement in an embodiment of the present invention. The placement of the additional DMRS may be associated with the placement of the forward-placed DMRS. For example, as shown in option 1 of Figure 13, the additional DMRS may be placed with the same density and in the same pattern as the forward-placed DMRS.

Also, as shown in option 2 of Fig. 13, the additional DMRS may be arranged in the same density but different pattern as the forward-placed DMRS. In option 2 of Fig. 13, the pattern of the additional DMRS is a pattern in which the first and second symbols of the forward-placed DMRS are replaced, and the forward-placed DMRS and the additional DMRS can have different comb patterns in the frequency domain.

Figure 14 is a diagram showing an example (8) of DMRS placement in an embodiment of the present invention. The additional DMRS may have a density in the time domain different from that of the forward-placed DMRS, or may have a density in the frequency domain different from that of the forward-placed DMRS. For example, since the additional DMRS is primarily intended for terminals 20 that move at high speeds and use channels with large time variations, resource elements where the density of the additional DMRS is low in the frequency domain may be supplemented by the forward-placed DMRS.

As shown in option 3-1 of Figure 14, by making the placement of the additional DMRS the same as only the first symbol of the forward-placed DMRS, the density of the additional DMRS in the time domain can be half that of the forward-placed DMRS, and the density of the additional DMRS in the frequency domain can be half that of the forward-placed DMRS.

As shown in option 3-2 of Figure 14, by placing the additional DMRS on two subcarriers every two subcarriers in the frequency domain and on both two symbols in the time domain, the density of the additional DMRS in the time domain can be made the same as that of the forward-placed DMRS, and the density of the additional DMRS in the frequency domain can be made half that of the forward-placed DMRS.

Note that the DMRS in the above-mentioned embodiment may be applied to the downlink or the uplink. Also, the base station 10 may transmit the DMRS in the above-mentioned embodiment together with the PDCCH and the PDSCH, and the terminal 20 may decode the PDCCH and the PDSCH based on the DMRS. Also, the terminal 20 may transmit the DMRS in the above-mentioned embodiment together with the PUCCH and the PUSCH, and the base station 10 may decode the PUCCH and the PUSCH based on the DMRS.

Furthermore, the terminal 20 may receive settings related to the DMRS in the above-mentioned embodiment from the base station 10. The terminal 20 may allocate the DMRS to radio resources based on the settings received from the base station 10, and may further allocate data to the radio resources and transmit them to the base station 10. The radio resources may be, for example, resource blocks, resource elements, or multiple symbols.

According to the above-mentioned embodiment, the base station 10 and the terminal 20 can reduce the resources used for the DMRS while maintaining the density of the frequency domain of the DMRS by placing the DMRS in different symbols with different comb patterns.

In other words, in a wireless communication system, a reference signal can be used to improve communication quality and reduce overhead.

(Device configuration)
Next, a functional configuration example of the base station 10 and the terminal 20 that execute the processes and operations described above will be described. The base station 10 and the terminal 20 include functions for implementing the above-mentioned embodiments. However, the base station 10 and the terminal 20 may each include only a part of the functions in the embodiments.

<Base Station 10>
Fig. 15 is a diagram showing an example of the functional configuration of the base station 10 in the embodiment of the present invention. As shown in Fig. 15, the base station 10 has a transmitting unit 110, a receiving unit 120, a setting unit 130, and a control unit 140. The functional configuration shown in Fig. 15 is merely an example. The names of the functional divisions and functional units may be any as long as they can execute the operations related to the embodiment of the present invention.

The transmitting unit 110 has a function of generating a signal to be transmitted to the terminal 20 side and transmitting the signal wirelessly. The transmitting unit 110 also transmits inter-network node messages to other network nodes. The receiving unit 120 has a function of receiving various signals transmitted from the terminal 20 and acquiring, for example, information of a higher layer from the received signals. The transmitting unit 110 also has a function of transmitting NR-PSS, NR-SSS, NR-PBCH, DL/UL control signals, etc. to the terminal 20. The receiving unit 120 also receives inter-network node messages from other network nodes.

The setting unit 130 stores preset setting information and various setting information to be transmitted to the terminal 20. The contents of the setting information include, for example, information related to the placement of the DMRS.

The control unit 140 performs control related to the placement of DMRS as described in the embodiments. The control unit 140 also controls communication by DSS. A functional unit related to signal transmission in the control unit 140 may be included in the transmitting unit 110, and a functional unit related to signal reception in the control unit 140 may be included in the receiving unit 120.

<Terminal 20>
Fig. 16 is a diagram showing an example of a functional configuration of the terminal 20 in the embodiment of the present invention. As shown in Fig. 16, the terminal 20 has a transmitting unit 210, a receiving unit 220, a setting unit 230, and a control unit 240. The functional configuration shown in Fig. 16 is merely an example. The names of the functional divisions and functional units may be any as long as they can execute the operations related to the embodiment of the present invention.

The transmitter 210 creates a transmission signal from the transmission data and transmits the transmission signal wirelessly. The receiver 220 wirelessly receives various signals and acquires higher layer signals from the received physical layer signals. The receiver 220 also has a function of receiving NR-PSS, NR-SSS, NR-PBCH, DL/UL/SL control signals, etc. transmitted from the base station 10. For example, the transmitter 210 transmits PSCCH (Physical Sidelink Control Channel), PSSCH (Physical Sidelink Shared Channel), PSDCH (Physical Sidelink Discovery Channel), PSBCH (Physical Sidelink Broadcast Channel), etc. to another terminal 20 as D2D communication, and the receiver 220 receives PSCCH, PSSCH, PSDCH, PSBCH, etc. from the other terminal 20.

The setting unit 230 stores various setting information received from the base station 10 by the receiving unit 220. The setting unit 230 also stores setting information that is set in advance. The contents of the setting information include, for example, information related to the placement of the DMRS.

The control unit 240 performs control related to the placement of the DMRS as described in the embodiment. The functional unit related to signal transmission in the control unit 240 may be included in the transmitting unit 210, and the functional unit related to signal reception in the control unit 240 may be included in the receiving unit 220.

(Hardware configuration)
The block diagrams (FIGS. 15 and 16) used in the description of the above embodiments show functional blocks. These functional blocks (components) are realized by any combination of at least one of hardware and software. The method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one device that is physically or logically coupled, or may be realized using two or more devices that are physically or logically separated and directly or indirectly connected (for example, using wires, wirelessly, etc.). The functional block may be realized by combining the one device or the multiple devices with software.

Functions include, but are not limited to, judgement, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, regard, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, and assignment. For example, a functional block (component) that performs the transmission function is called a transmitting unit or transmitter. As mentioned above, there are no particular limitations on the method of realization for either of these.

For example, the base station 10, terminal 20, etc. in one embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. FIG. 17 is a diagram showing an example of the hardware configuration of the base station 10 and terminal 20 in one embodiment of the present disclosure. The above-mentioned base station 10 and terminal 20 may be physically configured as a computer device including a processor 1001, a memory device 1002, an auxiliary memory device 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

In the following description, the term "apparatus" may be interpreted as a circuit, device, unit, etc. The hardware configuration of the base station 10 and the terminal 20 may be configured to include one or more of the devices shown in the figure, or may be configured to exclude some of the devices.

Each function in the base station 10 and the terminal 20 is realized by loading a specific software (program) onto hardware such as the processor 1001, the memory device 1002, etc., so that the processor 1001 performs calculations, controls communication by the communication device 1004, and controls at least one of the reading and writing of data in the memory device 1002 and the auxiliary memory device 1003.

The processor 1001, for example, operates an operating system to control the entire computer. The processor 1001 may be configured as a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, etc. For example, the above-mentioned control unit 140, control unit 240, etc. may be realized by the processor 1001.

The processor 1001 reads out a program (program code), a software module, or data, etc., from at least one of the auxiliary storage device 1003 and the communication device 1004 to the storage device 1002, and executes various processes according to the program. A program that causes a computer to execute at least a part of the operations described in the above-mentioned embodiment is used as the program. For example, the control unit 140 of the base station 10 shown in FIG. 15 may be realized by a control program stored in the storage device 1002 and operated by the processor 1001. For example, the control unit 240 of the terminal 20 shown in FIG. 16 may be realized by a control program stored in the storage device 1002 and operated by the processor 1001. Although the above-mentioned various processes have been described as being executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. The program may be transmitted from a network via a telecommunication line.

The storage device 1002 is a computer-readable recording medium, and may be composed of at least one of, for example, a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), a RAM (Random Access Memory), etc. The storage device 1002 may also be called a register, a cache, a main memory, etc. The storage device 1002 can store executable programs (program codes), software modules, etc. for implementing a communication method according to one embodiment of the present disclosure.

The auxiliary storage device 1003 is a computer-readable recording medium, and may be, for example, at least one of an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray (registered trademark) disk), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy (registered trademark) disk, a magnetic strip, etc. The above-mentioned storage medium may be, for example, a database, a server, or other suitable medium including at least one of the storage device 1002 and the auxiliary storage device 1003.

The communication device 1004 is hardware (transmitting/receiving device) for communicating between computers via at least one of a wired network and a wireless network, and is also called, for example, a network device, a network controller, a network card, a communication module, etc. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc., to realize at least one of Frequency Division Duplex (FDD) and Time Division Duplex (TDD). For example, a transmitting/receiving antenna, an amplifier unit, a transmitting/receiving unit, a transmission line interface, etc. may be realized by the communication device 1004. The transmitting/receiving unit may be implemented as a transmitting unit and a receiving unit that are physically or logically separated.

The input device 1005 is an input device (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (e.g., a display, a speaker, an LED lamp, etc.) that performs output to the outside. Note that the input device 1005 and the output device 1006 may be integrated into one configuration (e.g., a touch panel).

In addition, each device such as the processor 1001 and the storage device 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus, or may be configured using different buses between each device.

In addition, the base station 10 and the terminal 20 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these pieces of hardware.

(Summary of the embodiment)
As described above, according to an embodiment of the present invention, a terminal is provided which includes a receiving unit that receives settings related to a reference signal from a base station, a control unit that places a first reference signal based on the settings and data in a resource, and a transmitting unit that transmits the resource to the base station, wherein the control unit places the first reference signal in all frequency domains of the resource in a format in which frequency domain placements are different for consecutive first symbols and second symbols included in the resource.

With the above configuration, the terminal 20 can reduce the resources used for the DMRS while ensuring the density of the frequency domain of the DMRS by arranging the DMRS in different symbols with different comb patterns. In other words, in a wireless communication system, a reference signal that improves communication quality and suppresses overhead can be used.

The type may be a comb pattern in which the first reference signal is not placed in a portion of the frequency domain. With this configuration, the terminal 20 can reduce resources used for DMRS by using the comb pattern.

The comb pattern may be a type in which the first reference signal is arranged every other subcarrier, or a type in which the first reference signal is arranged every two subcarriers. With this configuration, the terminal 20 can reduce resources used for DMRS by using the comb pattern.

The control unit may apply a Time Division Orthogonal Cover Code (TD-OCC) to the first symbol and the second symbol. With this configuration, the terminal 20 can increase the number of DMRS ports.

The control unit may allocate the second reference signal to the resources at a density different from the density of the first reference signal. With this configuration, the terminal 20 can reduce the resources used for the additional DMRS.

Also, according to an embodiment of the present invention, a communication method is provided in which a terminal executes a receiving procedure for receiving settings related to a reference signal from a base station, a control procedure for allocating a first reference signal based on the settings and data in a resource, and a transmission procedure for transmitting the resource to the base station, the control procedure including a step of allocating the first reference signal in all frequency domains of the resource in a format in which frequency domain allocations are different for consecutive first and second symbols included in the resource.

With the above configuration, the terminal 20 can reduce the resources used for the DMRS while ensuring the density of the frequency domain of the DMRS by arranging the DMRS in different symbols with different comb patterns. In other words, in a wireless communication system, a reference signal that improves communication quality and suppresses overhead can be used.

(Supplementary description of the embodiment)
Although the embodiment of the present invention has been described above, the disclosed invention is not limited to such an embodiment, and those skilled in the art will understand various modifications, modifications, alternatives, replacements, and the like. Although the description has been given using specific numerical examples to facilitate understanding of the invention, unless otherwise specified, those numerical values are merely examples and any appropriate value may be used. The division of items in the above description is not essential to the present invention, and items described in two or more items may be used in combination as necessary, and items described in one item may be applied to items described in another item (as long as there is no contradiction). The boundaries of functional units or processing units in the functional block diagram do not necessarily correspond to the boundaries of physical parts. The operations of multiple functional units may be physically performed by one part, or the operations of one functional unit may be physically performed by multiple parts. The order of the processing procedures described in the embodiment may be changed as long as there is no contradiction. For convenience of processing description, the base station 10 and the terminal 20 have been described using functional block diagrams, but such devices may be realized by hardware, software, or a combination thereof. The software operated by the processor possessed by the base station 10 in accordance with an embodiment of the present invention and the software operated by the processor possessed by the terminal 20 in accordance with an embodiment of the present invention may each be stored in random access memory (RAM), flash memory, read only memory (ROM), EPROM, EEPROM, register, hard disk (HDD), removable disk, CD-ROM, database, server or any other suitable storage medium.

In addition, the notification of information is not limited to the aspects/embodiments described in the present disclosure, and may be performed using other methods. For example, the notification of information may be performed by physical layer signaling (e.g., DCI (Downlink Control Information), UCI (Uplink Control Information)), higher layer signaling (e.g., RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals, or combinations thereof. In addition, the RRC signaling may be called an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, etc.

Each aspect/embodiment described in this disclosure may be applied to at least one of systems utilizing LTE (Long Term Evolution), LTE-Advanced (LTE-A), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (new Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), or other suitable systems, and next generation systems enhanced based on these. In addition, multiple systems may be applied in combination (for example, a combination of at least one of LTE and LTE-A with 5G, etc.).

The processing steps, sequences, flow charts, etc. of each aspect/embodiment described herein may be reordered unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order and are not limited to the particular order presented.

In this specification, a specific operation performed by the base station 10 may be performed by its upper node in some cases. In a network consisting of one or more network nodes having a base station 10, it is clear that various operations performed for communication with the terminal 20 may be performed by at least one of the base station 10 and other network nodes other than the base station 10 (e.g., MME or S-GW, etc., but are not limited to these). Although the above example shows a case where there is one other network node other than the base station 10, the other network node may be a combination of multiple other network nodes (e.g., MME and S-GW).

The information or signals described in this disclosure may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer). They may be input and output via multiple network nodes.

The input and output information, etc. may be stored in a specific location (e.g., memory) or may be managed using a management table. The input and output information, etc. may be overwritten, updated, or added to. The output information, etc. may be deleted. The input information, etc. may be transmitted to another device.

In the present disclosure, the determination may be made based on a value represented by one bit (0 or 1), a Boolean (true or false) value, or a comparison of numerical values (e.g., comparison with a predetermined value).

Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Additionally, software, instructions, information, etc. may be transmitted and received via a transmission medium. For example, if the software is transmitted from a website, server, or other remote source using wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and/or wireless technologies (such as infrared, microwave), then these wired and/or wireless technologies are included within the definition of a transmission medium.

The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

Note that the terms described in this disclosure and the terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, at least one of the channel and the symbol may be a signal (signaling). Also, the signal may be a message. Also, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

As used in this disclosure, the terms "system" and "network" are used interchangeably.

In addition, the information, parameters, etc. described in this disclosure may be represented using absolute values, may be represented using relative values from a predetermined value, or may be represented using other corresponding information. For example, radio resources may be indicated by an index.

The names used for the above-mentioned parameters are not limiting in any way. Moreover, the formulas etc. using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not limiting in any way.

In this disclosure, terms such as "base station (BS)", "radio base station", "base station device", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission/reception point", "cell", "sector", "cell group", "carrier", and "component carrier" may be used interchangeably. A base station may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

A base station can accommodate one or more (e.g., three) cells. When a base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, and each smaller area can also provide communication services by a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head). The term "cell" or "sector" refers to a part or the entire coverage area of at least one of the base station and base station subsystem that provides communication services in this coverage.

In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" may be used interchangeably.

A mobile station may also be referred to by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable terminology.

At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. At least one of the base station and the mobile station may be a device mounted on a moving body, the moving body itself, etc. The moving body may be a vehicle (e.g., a car, an airplane, etc.), an unmanned moving body (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). At least one of the base station and the mobile station may include a device that does not necessarily move during communication operation. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

In addition, the base station in the present disclosure may be read as a user terminal. For example, each aspect/embodiment of the present disclosure may be applied to a configuration in which communication between a base station and a user terminal is replaced with communication between multiple terminals 20 (which may be called, for example, D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.). In this case, the terminal 20 may be configured to have the functions possessed by the base station 10 described above. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, the uplink channel, downlink channel, etc. may be read as a side channel.

Similarly, the user terminal in this disclosure may be interpreted as a base station. In this case, the base station may be configured to have the functions of the user terminal described above.

As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (e.g., searching in a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), and the like. In addition, "judgment" and "decision" can include considering resolving, selecting, choosing, establishing, comparing, etc., to be a "judgment" or "decision." In other words, "judgment" and "decision" can include considering some action to be a "judgment" or "decision." Furthermore, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

The terms "connected" and "coupled", or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connected" may be read as "access". As used in this disclosure, two elements may be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, as well as electromagnetic energy having wavelengths in the radio frequency range, microwave range, and light (both visible and invisible) range, as some non-limiting and non-exhaustive examples.

The reference signal may also be abbreviated as RS (Reference Signal) or may be called a pilot depending on the applicable standard.

As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

Any reference to elements using designations such as "first," "second," etc., used in this disclosure does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient way to distinguish between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must precede the second element in some way.

The "means" in the configuration of each of the above devices may be replaced with "part," "circuit," "device," etc.

When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Additionally, the term "or," as used in this disclosure, is not intended to be an exclusive or.

A radio frame may be composed of one or more frames in the time domain. Each of the one or more frames in the time domain may be called a subframe. A subframe may further be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) that is independent of numerology.

The numerology may be a communication parameter that applies to at least one of the transmission and reception of a signal or channel. The numerology may indicate at least one of, for example, the subcarrier spacing (SCS), the bandwidth, the symbol length, the cyclic prefix length, the transmission time interval (TTI), the number of symbols per TTI, the radio frame structure, a particular filtering operation performed by the transceiver in the frequency domain, and a particular windowing operation performed by the transceiver in the time domain.

A slot may consist of one or more symbols in the time domain (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol, a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol, etc.). A slot may be a time unit based on numerology.

A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

Radio frame, subframe, slot, minislot, and symbol all represent time units for transmitting signals. Radio frame, subframe, slot, minislot, and symbol may each be referred to by a different name.

For example, one subframe may be called a Transmission Time Interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. In other words, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (e.g., 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc., instead of a subframe.

Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station schedules each terminal 20 by allocating wireless resources (such as frequency bandwidth and transmission power that can be used by each terminal 20) in TTI units. Note that the definition of TTI is not limited to this.

A TTI may be a transmission time unit for a channel-coded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) in which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

In addition, when one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit of scheduling. In addition, the number of slots (minislots) constituting the minimum time unit of scheduling may be controlled.

A TTI having a time length of 1 ms may be called a normal TTI (TTI in LTE Rel. 8-12), normal TTI, long TTI, normal subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a normal TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

Note that a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length exceeding 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length less than the TTI length of a long TTI and equal to or greater than 1 ms.

A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of the numerology, for example, 12. The number of subcarriers included in an RB may be determined based on the numerology.

In addition, the time domain of an RB may include one or more symbols and may be one slot, one minislot, one subframe, or one TTI in length. Each TTI, subframe, etc. may be composed of one or more resource blocks.

In addition, one or more RBs may be referred to as a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, etc.

A resource block may also be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

A Bandwidth Part (BWP), which may also be referred to as a partial bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by an index of the RB relative to a Common Reference Point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

The BWP may include a BWP for UL (UL BWP) and a BWP for DL (DL BWP). One or more BWPs may be configured for a UE within one carrier.

At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal/channel outside the active BWP. Note that the terms "cell", "carrier", etc. in this disclosure may be read as "BWP".

The above-mentioned structures of radio frames, subframes, slots, minislots, and symbols are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, as well as the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, and other configurations can be changed in various ways.

In this disclosure, where articles have been added by translation, such as a, an, and the in English, this disclosure may include that the nouns following these articles are in the plural form.

In this disclosure, the term "A and B are different" may mean "A and B are different from each other." In addition, the term may mean "A and B are each different from C." Terms such as "separate" and "combined" may also be interpreted in the same way as "different."

Each aspect/embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. In addition, notification of specific information (e.g., notification that "X is the case") is not limited to being done explicitly, but may be done implicitly (e.g., not notifying the specific information).

In addition, the DMRS in this disclosure is an example of a reference signal. The forward-placed DMRS is an example of a first reference signal. The additional DMRS is an example of a second reference signal. The PDCCH and PDSCH, the PUCCH and the PUSCH are examples of data.

Although the present disclosure has been described in detail above, it is clear to those skilled in the art that the present disclosure is not limited to the embodiments described herein. The present disclosure can be implemented in modified and altered forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is intended to be illustrative and does not have any limiting meaning on the present disclosure.

10 Base station 110 Transmitter 120 Receiver 130 Setting unit 140 Control unit 20 Terminal 210 Transmitter 220 Receiver 230 Setting unit 240 Control unit 1001 Processor 1002 Storage device 1003 Auxiliary storage device 1004 Communication device 1005 Input device 1006 Output device

Claims (3)

A receiving unit that receives a setting related to a reference signal from a base station;
A control unit that allocates a first reference signal based on the setting and data to resources;
a transmitting unit configured to transmit the resource to the base station ;
The control unit arranges the first reference signal in the entire frequency domain of the resource in a format in which the frequency domain arrangement is different for consecutive first symbols and second symbols included in the resource,
The type is a comb pattern in which the first reference signal is not placed in a part of a frequency region,
The comb pattern is a type in which the first reference signal is arranged on every other subcarrier, or a type in which the first reference signal is arranged on every third subcarrier,
The control unit applies a Time Division Orthogonal Cover Code (TD-OCC) to the first symbol and the second symbol . The terminal according to claim 1, wherein the control unit allocates the second reference signal to the resources at a density different from the density of the first reference signal. A receiving procedure for receiving a configuration related to a reference signal from a base station;
A control procedure for allocating a first reference signal and data based on the configuration to resources;
a transmission procedure for transmitting the resource to the base station by the terminal ;
The control step includes a step of arranging the first reference signal in the entire frequency domain of the resource in a manner that the frequency domain arrangement is different for a first symbol and a second symbol that are consecutive and included in the resource;
The type is a comb pattern in which the first reference signal is not placed in a part of a frequency region,
The comb pattern is a type in which the first reference signal is arranged on every other subcarrier, or a type in which the first reference signal is arranged on every third subcarrier,
The control procedure is a communication method in which a Time Division Orthogonal Cover Code (TD-OCC) is applied to the first symbol and the second symbol .

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