WO2024079915A1

WO2024079915A1 - Terminal and communication method

Info

Publication number: WO2024079915A1
Application number: PCT/JP2022/038487
Authority: WO
Inventors: 翔一樋口; 大樹武田
Original assignee: 株式会社Ｎｔｔドコモ
Priority date: 2022-10-14
Filing date: 2022-10-14
Publication date: 2024-04-18

Abstract

This terminal comprises: a reception unit that receives a signal in a moving environment in which a single carrier frequency is used; and a control unit that corrects a Doppler frequency shift of the signal. The control unit corrects a first Doppler frequency shift amount corresponding to a spot where the Doppler frequency shift instantaneously changes, and corrects a second Doppler frequency shift amount corresponding to a spot where the Doppler frequency shift continuously changes.

Description

Terminal and communication method

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 many terminals, low cost, and low power consumption (for example, Non-Patent Document 1).

3GPP (registered trademark) specifications have introduced tests to ensure reception performance for HST (High Speed Train) (for example, non-patent document 2). In the HST specifications, models that represent actual HST environments are created and introduced for each model. For example, models of HST environments include single tap, HST-SFN (Single Frequency Network), and HST-DPS (Dynamic Point Selection).

　In existing HST tests, one possible Doppler frequency shift is specified for an entire model. In other words, the value at the point most affected by the Doppler frequency shift in an entire model is applied to the HST test. However, with this specification, there were cases where the value of the Doppler frequency shift assumed in the SFN model was not appropriate.

The present invention has been made in consideration of the above points, and aims to appropriately estimate the amount of Doppler frequency shift in a wireless communication system.

According to the disclosed technology, a terminal is provided that has a receiving unit that receives a signal in a moving environment where a single carrier frequency is used, and a control unit that corrects the Doppler frequency shift of the signal, the control unit correcting a first Doppler frequency shift amount corresponding to a point where the Doppler frequency shift changes instantaneously, and correcting a second Doppler frequency shift amount corresponding to a point where the Doppler frequency shift changes continuously.

The disclosed technology makes it possible to appropriately estimate the amount of Doppler frequency shift in a wireless communication system.

FIG. 1 is a diagram showing a configuration example (1) of a wireless communication system. FIG. 1 is a diagram showing a configuration example (2) of a wireless communication system. A diagram for explaining an example of an HST-SFN environment. FIG. 1 shows a model (1) of Doppler shift in an HST-SFN environment. FIG. 13 is a diagram showing a model of Doppler shift in a single tap. A figure showing model (2) of Doppler shift in an HST-SFN environment. FIG. 2 is a diagram for explaining a testing method according to 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. FIG. 2 is a diagram showing an example of the configuration of a vehicle 2001 according to an embodiment of the present invention.

Below, 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 can be applied is not limited to the following embodiment.

In operating the wireless communication system according to the embodiment of the present invention, existing technology is used as appropriate. 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), which are used in existing LTE, are used. This is for convenience of description, and similar signals, functions, etc. may be called by other names. Furthermore, 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-".

Furthermore, 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 the embodiment of the present invention, when radio parameters and the like 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.

FIG. 1 is a diagram showing a configuration example (1) of a wireless communication system in an embodiment of the present invention. As shown in FIG. 1, the wireless communication system in the embodiment of the present invention includes a base station 10 and a terminal 20. Although FIG. 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, where 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 are capable of transmitting and receiving signals by performing beamforming. In addition, both the base station 10 and the terminal 20 can apply MIMO (Multiple Input Multiple Output) communication 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) using CA (Carrier Aggregation). Furthermore, the terminal 20 may communicate via a primary cell of the base station 10 and a primary secondary cell group cell (PSCell: Primary SCG Cell) of another base station 10 using 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.

The terminal 20 is capable of performing carrier aggregation, which bundles multiple cells (multiple CCs (Component Carriers)) together to communicate with the base station 10. In carrier aggregation, one PCell (Primary cell) and one or more SCells (Secondary cells) are used. A PUCCH-SCell having a PUCCH may also be used.

FIG. 2 is a diagram showing an example (2) of a wireless communication system in an embodiment of the present invention. FIG. 2 shows an example of the configuration of a wireless communication system when DC (Dual connectivity) is implemented. As shown in FIG. 2, a base station 10A serving as a MN (Master Node) and a base station 10B serving as a SN (Secondary Node) are provided. Base station 10A and base station 10B are each connected to a core network. Terminal 20 can communicate with both base station 10A and base station 10B.

The cell group provided by base station 10A, which is an MN, is called the MCG (Master Cell Group), and the cell group provided by base station 10B, which is an SN, is called the SCG (Secondary Cell Group). In addition, in DC, the MCG is composed of one PCell and one or more SCells, and the SCG is composed of one PSCell (Primary SCG Cell) and one or more SCells.

The processing operations in this embodiment may be performed in the system configuration shown in FIG. 1, in the system configuration shown in FIG. 2, or in a system configuration other than these.

The 3GPP regulations introduce tests to ensure reception performance for HST (High Speed Train) (for example, non-patent document 2). In the HST regulations, models that represent actual HST environments are created and introduced for each model. For example, models of HST environments include single tap, HST-SFN (Single Frequency Network), and HST-DPS (Dynamic Point Selection).

The terminal 20 performs a test on reception performance by correcting for the Doppler frequency shift assumed in the above model of the HST environment.

The specifications for HST-SFN are shown, for example, in the following receiving performance and models:

Table 1 shows the specified values for the minimum receiving performance for rank 2 (see non-patent document 2). As shown in Table 1, the propagation conditions are HST-SFN.

Figure 3 is a diagram for explaining an example of an HST-SFN environment. Figure 3 shows the layout of an HST-SFN environment. As shown in Figure 3, RRHs are arranged at equal intervals on a straight line, and the HST travels on the straight line. Each RRH transmits at the same frequency.

Figure 4 shows a model (1) of Doppler shift in an HST-SFN environment (see Non-Patent Document 2). In addition to modeling the HST environment, the HST specification specifies the degree of Doppler to be assumed, as shown in Figure 4. The Doppler that can be assumed for the entire model is specified.

In the example of Fig. 4, a Doppler frequency shift of 870 Hz is assumed. As shown in Fig. 4, RRH _k-1 , RRH _k , RRH _k+1 , RRH _k+2 , RRH _k+3 , RRH _k+4 , and RRH _k+5 are arranged in the direction of travel of the HST.

The Doppler frequency shift is calculated by carrier frequency x HST speed / speed of light. 870 Hz corresponds to a carrier frequency of 1.88 GHz and an HST speed of 500 km/h.

Figure 5 shows a model of the Doppler shift in a single tap (see Non-Patent Document 2). The single tap model shown in Figure 5 assumes a Doppler frequency shift of 972 Hz. 972 Hz corresponds to a carrier frequency of 2.1 GHz and an HST speed of 500 km/h.

Table 2 shows examples of reception performance specifications and test conditions for HST.

As shown in Table 2, the communication direction, station configuration, moving speed, tolerable Doppler frequency shift, and frequency are specified. As station configuration, normal configuration and SFN scenario are specified. As moving speed, 300 km/h, 350 km/h, and 500 km/h are specified.

The tolerable Doppler frequency shifts in LTE are specified as 750 Hz, 875 Hz, 1,340 Hz, 972 Hz, and 1,944 Hz. The tolerable Doppler frequency shifts in NR are specified as 750 Hz (15 kHz subcarrier spacing), 1,000 Hz (30 kHz subcarrier spacing), 972 Hz (15 kHz subcarrier spacing), 1,667 Hz (30 kHz subcarrier spacing), 870 Hz (15 kHz subcarrier spacing), 1,667 Hz (30 kHz subcarrier spacing), 1,740 Hz (15 kHz subcarrier spacing), and 3,334 Hz (30 kHz subcarrier spacing).

As shown in Table 2, the communication direction is specified for downstream and upstream, and in the upstream direction, a larger Doppler frequency shift must be taken into consideration in order to synchronize with the downstream signal that has been Doppler frequency shifted. Note that the frequencies in Table 2 are values calculated from the moving speed and the tolerable Doppler frequency shift.

Figure 6 shows model (2) of Doppler shift in an HST-SFN environment. As shown in Figure 6, a signal that has undergone a negative Doppler frequency shift is received from an RRH behind the position of terminal 20, and a signal that has undergone a positive Doppler frequency shift is received from an RRH ahead of the position of terminal 20. The positive and negative Doppler frequency shift changes before and after terminal 20 passes the position of the RRH.

　Existing HST tests specify one possible Doppler frequency shift for an entire model. That is, the value at the point in the entire model that is most affected by the Doppler frequency shift is applied to the HST test.

For example, the two test patterns shown below are assumed to be specified.

Test pattern 1: frequency α ₁ Hz and speed β ₁ km/h
Doppler frequency shift at point A: 120 Hz
Doppler frequency shift at point B: 60 Hz

Test pattern 2: Frequency α ₂ Hz and speed β ₂ km/h
Doppler frequency shift at point A: 100 Hz
Doppler frequency shift at point B: 50 Hz

Here, if the limit of the Doppler frequency shift that terminal 20 can correct is 100 Hz, test pattern 2 is selected.

However, in this regulation, the Doppler frequency shift value assumed in the SFN model (HST-SFN, HST-DPS, HST-SFN scheme A/B) was sometimes inappropriate.

FIG. 7 is a diagram for explaining a test method in an embodiment of the present invention. As shown in FIG. 7, the SFN model (HST-SFN, HST-DPS, HST-SFN scheme A/B) has the advantage of being able to suppress handovers, but when the terminal 20 switches its connection from a rear base station 10 to a front base station 10, a large change in Doppler frequency shift occurs. For this reason, the HST test uses a Doppler frequency shift based on the switching point.

When considering the actual communication environment, as shown in Figure 7, the only points where large changes in Doppler frequency shift occur are at the cell edges, and in areas other than the cell edges where the HST takes a long time to pass, tests cannot be performed even if the Doppler frequency shift is actually predictable. In other words, the performance of terminal 20 is not guaranteed.

The large Doppler frequency shift changes that occur in the SFN model are instantaneous changes from negative to positive. On the other hand, in areas of the SFN model where there are no instantaneous changes from negative to positive, the Doppler frequency shift changes continuously. Because no instantaneous changes occur in these areas, it is possible to introduce tests that assume larger changes in Doppler frequency shift in areas other than the cell edge than when the cell edge is assumed.

For example, as a rule for FDD considering the same speed of 500 km/h, between an HST-SFN model in which the Doppler frequency shift changes instantaneously from negative to positive and a single tap model in which the Doppler frequency shift changes continuously, the HST-SFN model may assume a Doppler frequency shift of 870 Hz, and the single tap model may assume a Doppler frequency shift of 972 Hz.

As mentioned above, in the SFN model, even if a frequency can be supported at a point other than the switching point of the base station 10, it may not be possible to test it using the existing HST test method. Therefore, it may be possible to specify tests for HST as described below.

As tests for HST, a test that assumes a point where the Doppler frequency shift changes instantaneously, i.e., a switching point of the base station 10, and a test that assumes a point where the Doppler frequency shift changes continuously, i.e., a point other than the switching point of the base station 10, may be introduced. For each test, a model of the reception performance and HST environment that the terminal 20 must satisfy may be specified.

In addition to the existing HST test, a test may be introduced that assumes a point where the Doppler frequency shift changes continuously, i.e., other than the switching point of the base station 10.

For example, the following tests A and B may be implemented.

Test A: A test simulating a point where the Doppler frequency shift changes instantaneously. The Doppler frequency shift value assumed for the test is 870 Hz, the carrier frequency is 1.88 GHz, and the speed of the HST is 500 km/h.

Test B: A test assuming a location where the Doppler frequency shift changes continuously. The Doppler frequency shift value assumed for the test is 972 Hz, the carrier frequency is 2.1 GHz, and the HST speed is 500 km/h.

Note that the assumed values for the above tests are examples. For example, a test in which the assumed Doppler frequency shift is larger than that of test A may be specified as test B.

By being able to test terminal 20 using a combination of Test A and Test B, or a combination of the existing HST test and Test B, the existing HST test was unable to distinguish between locations and could only test under 870 Hz conditions. However, by introducing Test B, it is now possible to test at 972 Hz, which is a stricter Doppler condition than 870 Hz and can guarantee the original performance.

A UE capability may be introduced that indicates whether the terminal 10 has the capability to pass test B. The network may change the frequency assigned to the terminal 20 based on the UE capability. For example, the frequency assumed in test B may be assigned to the terminal 20 that reports the UE capability to the network.

Furthermore, the frequency assumed in test B may be assigned only as a secondary cell to the terminal 20 that has reported the UE capability to the network. At points where the Doppler frequency shift changes instantaneously, the frequency assumed in test B may not be supported, so for example, a 1 GHz primary cell may be assigned to a terminal 20 that passes test A, and a 2 GHz secondary cell may be assigned to a terminal 20 that passes test B.

Although an example with one test A and one test B has been shown, the number of each test is not limited to one. For example, if multiple points can be assumed within one HST model as points where the Doppler frequency shift changes instantaneously or points where the Doppler frequency shift changes continuously, the number of tests may be increased to correspond to each of the multiple points.

In addition, although the embodiment has been described using the SFN model, the model is not limited. If a new HST model is introduced in the future that contains a mixture of points where the Doppler frequency shift changes instantaneously and points where the Doppler frequency shift changes continuously, the embodiment of the present invention may be applied to that HST model.

Although the embodiment described assumes that the HST is a railway, the means of transportation is not limited thereto. It may be replaced with another means of transportation, for example, an airplane.

The above-mentioned embodiment makes it possible to assume multiple Doppler frequency shift amounts according to communication conditions in the SFN model and perform appropriate performance evaluation.

In other words, the amount of Doppler frequency shift can be appropriately estimated in a wireless communication system.

(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. 8 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. 8, 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. 8 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 Doppler frequency shift correction.

The control unit 140 performs control related to Doppler frequency shift correction as described in the embodiment. The functional unit related to signal transmission in the control unit 140 may be included in the transmitting unit 110, and the functional unit related to signal reception in the control unit 140 may be included in the receiving unit 120.

<Terminal 20>
Fig. 9 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. 9, 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. 9 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 Doppler frequency shift correction.

The control unit 240 performs control related to Doppler frequency shift correction 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. 8 and 9) 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.) and these multiple devices. 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. 10 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 storage device 1002, an auxiliary storage 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" can 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.

The functions of the base station 10 and the terminal 20 are realized by loading specific software (programs) onto hardware such as the processor 1001 and the storage device 1002, causing the processor 1001 to perform calculations, control communications by the communication device 1004, and control at least one of the reading and writing of data in the storage device 1002 and the auxiliary storage 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, registers, 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), software module, 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. The program is a program that causes a computer to execute at least a part of the operations described in the above-mentioned embodiment. For example, the control unit 140 of the base station 10 shown in FIG. 8 may be stored in the storage device 1002 and realized by a control program that runs on the processor 1001. For example, the control unit 240 of the terminal 20 shown in FIG. 9 may be stored in the storage device 1002 and realized by a control program that runs on 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, for example, at least one of 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 relating 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 that includes 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 referred to as, 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, for example, Frequency Division Duplex (FDD) and Time Division Duplex (TDD). For example, the transmitting/receiving antenna, an amplifier unit, a transmitting/receiving unit, a transmission path interface, etc. may be realized by the communication device 1004. The transmitting/receiving unit may be implemented as a transmitting unit or a receiving unit that is 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 structure (e.g., a touch panel).

Furthermore, 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.

Furthermore, 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.

FIG. 11 shows an example configuration of a vehicle 2001. As shown in FIG. 11, the vehicle 2001 includes a drive unit 2002, a steering unit 2003, an accelerator pedal 2004, a brake pedal 2005, a shift lever 2006, front wheels 2007, rear wheels 2008, an axle 2009, an electronic control unit 2010, various sensors 2021-2029, an information service unit 2012, and a communication module 2013. Each aspect/embodiment described in this disclosure may be applied to a communication device mounted on the vehicle 2001, and may be applied to the communication module 2013, for example.

The drive unit 2002 is composed of, for example, an engine, a motor, or a hybrid of an engine and a motor. The steering unit 2003 includes at least a steering wheel (also called a handlebar), and is configured to steer at least one of the front wheels and the rear wheels based on the operation of the steering wheel operated by the user.

The electronic control unit 2010 is composed of a microprocessor 2031, memory (ROM, RAM) 2032, and a communication port (IO port) 2033. Signals are input to the electronic control unit 2010 from various sensors 2021 to 2029 provided in the vehicle 2001. The electronic control unit 2010 may also be called an ECU (Electronic Control Unit).

Signals from the various sensors 2021-2029 include a current signal from a current sensor 2021 that senses the motor current, a front and rear wheel rotation speed signal obtained by a rotation speed sensor 2022, a front and rear wheel air pressure signal obtained by an air pressure sensor 2023, a vehicle speed signal obtained by a vehicle speed sensor 2024, an acceleration signal obtained by an acceleration sensor 2025, an accelerator pedal depression amount signal obtained by an accelerator pedal sensor 2029, a brake pedal depression amount signal obtained by a brake pedal sensor 2026, a shift lever operation signal obtained by a shift lever sensor 2027, and a detection signal for detecting obstacles, vehicles, pedestrians, etc. obtained by an object detection sensor 2028.

The information service unit 2012 is composed of various devices, such as a car navigation system, an audio system, speakers, a television, and a radio, for providing (outputting) various information such as driving information, traffic information, and entertainment information, and one or more ECUs for controlling these devices. The information service unit 2012 uses information acquired from an external device via the communication module 2013 or the like to provide various multimedia information and multimedia services to the occupants of the vehicle 2001. The information service unit 2012 may include input devices (e.g., a keyboard, a mouse, a microphone, a switch, a button, a sensor, a touch panel, etc.) that accept input from the outside, and may also include output devices (e.g., a display, a speaker, an LED lamp, a touch panel, etc.) that perform output to the outside.

The driving assistance system unit 2030 is composed of various devices that provide functions for preventing accidents and reducing the driving burden on the driver, such as a millimeter wave radar, LiDAR (Light Detection and Ranging), a camera, a positioning locator (e.g., GNSS, etc.), map information (e.g., high definition (HD) maps, autonomous vehicle (AV) maps, etc.), a gyro system (e.g., IMU (Inertial Measurement Unit), INS (Inertial Navigation System), etc.), AI (Artificial Intelligence) chip, and AI processor, as well as one or more ECUs that control these devices. In addition, the driving assistance system unit 2030 transmits and receives various information via the communication module 2013 to realize driving assistance functions or autonomous driving functions.

The communication module 2013 can communicate with the microprocessor 2031 and components of the vehicle 2001 via the communication port. For example, the communication module 2013 transmits and receives data via the communication port 2033 between the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axle 2009, microprocessor 2031 and memory (ROM, RAM) 2032 in the electronic control unit 2010, and sensors 2021 to 29, which are provided on the vehicle 2001.

The communication module 2013 is a communication device that can be controlled by the microprocessor 2031 of the electronic control unit 2010 and can communicate with an external device. For example, it transmits and receives various information to and from the external device via wireless communication. The communication module 2013 may be located either inside or outside the electronic control unit 2010. The external device may be, for example, a base station, a mobile station, etc.

The communication module 2013 may transmit at least one of the signals from the various sensors 2021-2028 described above input to the electronic control unit 2010, information obtained based on the signals, and information based on input from the outside (user) obtained via the information service unit 2012 to an external device via wireless communication. The electronic control unit 2010, the various sensors 2021-2028, the information service unit 2012, etc. may be referred to as input units that accept input. For example, the PUSCH transmitted by the communication module 2013 may include information based on the above input.

The communication module 2013 receives various information (traffic information, signal information, vehicle distance information, etc.) transmitted from an external device and displays it on the information service unit 2012 provided in the vehicle 2001. The information service unit 2012 may be called an output unit that outputs information (for example, outputs information to a device such as a display or speaker based on the PDSCH (or data/information decoded from the PDSCH) received by the communication module 2013). The communication module 2013 also stores various information received from an external device in a memory 2032 that can be used by the microprocessor 2031. Based on the information stored in the memory 2032, the microprocessor 2031 may control the drive unit 2002, steering unit 2003, accelerator pedal 2004, brake pedal 2005, shift lever 2006, front wheels 2007, rear wheels 2008, axles 2009, sensors 2021 to 2029, etc. provided in the vehicle 2001.

(Summary of the embodiment)
As described above, according to an embodiment of the present invention, there is provided a terminal having a receiving unit that receives a signal in a moving environment where a single carrier frequency is used, and a control unit that corrects a Doppler frequency shift of the signal, wherein the control unit corrects a first amount of Doppler frequency shift corresponding to a point where the Doppler frequency shift changes instantaneously, and corrects a second amount of Doppler frequency shift corresponding to a point where the Doppler frequency shift changes continuously.

The above configuration makes it possible to assume multiple Doppler frequency shift amounts according to communication conditions in the SFN model and perform appropriate performance evaluation. In other words, it is possible to appropriately assume the Doppler frequency shift amount in a wireless communication system.

The second Doppler frequency shift amount may be greater than the first Doppler frequency shift amount. With this configuration, in the SFN model, it is possible to assume multiple Doppler frequency shift amounts according to communication conditions and perform appropriate performance evaluation.

The receiving unit may receive at a point where the Doppler frequency shift changes continuously at a carrier frequency higher than the carrier frequency at the point where the Doppler frequency shift changes instantaneously. With this configuration, it is possible to assume multiple Doppler frequency shift amounts according to communication conditions in the SFN model and perform appropriate performance evaluation.

The control unit may connect to a secondary cell at the high carrier frequency. With this configuration, in the SFN model, it is possible to assume multiple Doppler frequency shift amounts according to communication conditions and perform appropriate performance evaluation.

The control unit may correct multiple Doppler frequency shift amounts corresponding to multiple points where the Doppler frequency shift switches instantaneously, and may correct multiple Doppler frequency shift amounts corresponding to multiple points where the Doppler frequency shift switches continuously. With this configuration, it is possible to assume multiple Doppler frequency shift amounts according to communication conditions in the SFN model and perform appropriate performance evaluation.

Furthermore, according to an embodiment of the present invention, a communication method is provided in which a terminal executes a reception procedure for receiving a signal in a moving environment where a single carrier frequency is used, a control procedure for correcting the Doppler frequency shift of the signal, a procedure for correcting a first Doppler frequency shift amount corresponding to a point where the Doppler frequency shift changes instantaneously, and a procedure for correcting a second Doppler frequency shift amount corresponding to a point where the Doppler frequency shift changes continuously.

(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 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.

Furthermore, 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., Downlink Control Information (DCI), Uplink Control Information (UCI)), higher layer signaling (e.g., Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling), broadcast information (Master Information Block (MIB), System Information Block (SIB)), other signals, or a combination of these. Furthermore, RRC signaling may be referred to as 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 a mobile communication system (mobile communications system) for mobile communications over a wide range of networks, including LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), 6th generation mobile communication system (6G), xth generation mobile communication system (xG) (xG (x is, for example, an integer or a decimal number)), FRA (Future Ra The present invention may be applied to at least one of systems using IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), and other appropriate systems, and next-generation systems that are expanded, modified, created, or defined based on these. It may also be applied to a combination of multiple systems (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 exemplary order and are not limited to the particular order presented.

In this specification, certain operations that are described as being performed by the base station 10 may in some cases be performed by its upper node. 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 a terminal 20 may be performed by at least one of the base station 10 and other network nodes other than the base station 10 (such as, but not limited to, an MME or S-GW). 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 (such as an MME and an 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 may be stored in a specific location (e.g., memory) or may be managed using a management table. The input and output information may be overwritten, updated, or added to. The output information may be deleted. The input information may be sent to another device.

The determination in this disclosure may be 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., a 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.

Software, instructions, information, etc. may also be transmitted and received via a transmission medium. For example, if the software is transmitted from a website, server, or other remote source using at least one of wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and/or wireless technologies (such as infrared, microwave), then at least one of these wired and wireless technologies is 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, the 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 explained 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, the 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, a radio resource may be indicated by an index.

The names used for the above-mentioned parameters are not limiting in any respect. Furthermore, 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 respect.

In this disclosure, terms such as "base station (BS)", "wireless 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 subsystems that provide communication services in this coverage.

In this disclosure, a base station transmitting information to a terminal may be interpreted as the base station instructing the terminal to control or operate based on the information.

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 object, the moving object itself, etc. The moving object is a movable object, and the moving speed is arbitrary. It also includes the case where the moving object is stopped. The moving object includes, but is not limited to, for example, a vehicle, a transport vehicle, an automobile, a motorcycle, a bicycle, a connected car, an excavator, a bulldozer, a wheel loader, a dump truck, a forklift, a train, a bus, a handcar, a rickshaw, a ship and other watercraft, an airplane, a rocket, an artificial satellite, a drone (registered trademark), a multicopter, a quadcopter, a balloon, and objects mounted thereon. The moving object may also be a moving object that travels autonomously based on an operation command. It may be a vehicle (e.g., a car, an airplane, etc.), an unmanned moving object (e.g., a drone, an autonomous vehicle, etc.), or a robot (manned or unmanned). In addition, at least one of the base station and the mobile station may be a device that does not necessarily move during communication operations. 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.

Furthermore, 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) or V2X (Vehicle-to-Everything)). In this case, the terminal 20 may be configured to have the functions of 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, search, inquiry (e.g., searching in a table, database, or other data structure), and considering ascertaining as "judging" or "determining." Also, "determining" and "determining" may include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), and considering ascertaining as "judging" or "determining." Additionally, "judgment" and "decision" can include considering resolving, selecting, choosing, establishing, comparing, etc., to have been "judged" or "decided." In other words, "judgment" and "decision" can include considering some action to have been "judged" or "decided." Additionally, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

The terms "connected," "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 optical (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 an element using a designation 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 method of distinguishing 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 the terms "include," "including," and variations thereof are used in this disclosure, these terms 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.

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

A slot may consist of one or more symbols in the time domain (such as OFDM (Orthogonal Frequency Division Multiplexing) symbols, SC-FDMA (Single Carrier Frequency Division Multiple Access) symbols, 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 that corresponds to the radio frame, subframe, slot, minislot, and symbol.

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 performs scheduling to allocate wireless resources (such as frequency bandwidth and transmission power that can be used by each terminal 20) to each terminal 20 in TTI units. Note that the definition of TTI is not limited to this.

The 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.

Note that 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) that constitute 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 of more than 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, and may be, for example, 12. The number of subcarriers included in an RB may be determined based on the numerology.

Furthermore, 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. One TTI, one subframe, etc. may each 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.

Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource area 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 "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, and the cyclic prefix (CP) length can be changed in various ways.

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

In this disclosure, the term "A and B are different" may mean "A and B are different from each other." The term may also 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 execution. 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).

　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 as an illustrative example and does not have any limiting meaning with respect to 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 2001 Vehicle 2002 Drive unit 2003 Steering unit 2004 Accelerator pedal 2005 Brake pedal 2006 Shift lever 2007 Front wheel 2008 Rear wheel 2009 Axle 2010 Electronic control unit 2012 Information service unit 2013 Communication module 2021 Current sensor 2022 Rotational speed sensor 2023 Air pressure sensor 2024 Vehicle speed sensor 2025 Acceleration sensor 2026 Brake pedal sensor 2027 Shift lever sensor 2028 Object detection sensor 2029 Accelerator pedal sensor 2030 Driving support system unit 2031 Microprocessor 2032 Memory (ROM, RAM)
2033 Communication port (IO port)

Claims

A receiver for receiving signals in a moving environment where a single carrier frequency is used;
and a control unit for correcting a Doppler frequency shift of the signal.
The control unit corrects a first Doppler frequency shift amount corresponding to a point where the Doppler frequency shift changes instantaneously, and corrects a second Doppler frequency shift amount corresponding to a point where the Doppler frequency shift changes continuously.
The terminal of claim 1, wherein the second Doppler frequency shift amount is greater than the first Doppler frequency shift amount.
The terminal according to claim 1, wherein the receiving unit receives at a point where the Doppler frequency shift changes continuously at a carrier frequency higher than the carrier frequency at the point where the Doppler frequency shift changes instantaneously.
The terminal according to claim 3, wherein the control unit connects to a secondary cell at the high carrier frequency.
The terminal according to claim 1, wherein the control unit corrects a plurality of Doppler frequency shift amounts corresponding to a plurality of points where the Doppler frequency shift changes instantaneously, and corrects a plurality of Doppler frequency shift amounts corresponding to a plurality of points where the Doppler frequency shift changes continuously.
A receiving procedure for receiving a signal in a moving environment where a single carrier frequency is used;
a control procedure for correcting a Doppler frequency shift of said signal;
A communication method in which a terminal executes a procedure for correcting a first Doppler frequency shift amount corresponding to a point where the Doppler frequency shift changes instantaneously, and a procedure for correcting a second Doppler frequency shift amount corresponding to a point where the Doppler frequency shift changes continuously.