Terminal, base station, and communication method

Abstract

To provide a terminal that can properly receive a signal transmitted by a plurality of base stations linking to each other.SOLUTION: A terminal comprises: a reception section that receives a carrier from each of a plurality of base stations linking to each other to transmit a signal; and a control section that controls a reception frequency of each carrier on the basis of a reference signal included in the carrier and estimates a signal on the basis of a decoding result from decoding in each carrier.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present disclosure relates to a terminal, a base station, and a communication method. [Background technology]

[0002] In 5G (5th generation mobile communication system), massive multiple input multiple output (MIMO) using multi-element antennas is one of the main technologies. For example, in massive MIMO, sharp beams are generated by beamforming to realize high-speed, large-capacity communication (see, for example, Patent Document 1). In addition, in massive MIMO, high-speed, large-capacity communication is realized by multiplex transmission of multiple users or multiple streams.

[0003] In order to realize even higher speed and larger capacity communication in future smokeless communication systems, the use of millimeter wave bands that allow for wider bandwidth is being considered. For example, millimeter wave bands have larger path loss and shorter transmission distance than sub-6, so the communication area is narrow and communication between base stations and moving terminals can be unstable. For this reason, technology is being considered in which multiple base stations work together to communicate with terminals. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 008212 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in wireless communication in which multiple base stations cooperate with each other, when a terminal moves, a frequency shift may occur in the carrier waves of each base station, and therefore the terminal may not be able to properly receive signals transmitted by the multiple base stations in cooperation with each other.

[0006] One aspect of the present disclosure is that a terminal properly receives signals transmitted in cooperation from a plurality of base stations. [Means for solving the problem]

[0007] A terminal according to one embodiment of the present disclosure has a receiving unit that receives carrier waves from each of a plurality of base stations that transmit signals in cooperation with each other, and a control unit that controls the receiving frequency of each of the carrier waves based on a reference signal contained in each of the carrier waves, and estimates the signal based on a decoding result of a decoding process in each of the carrier waves.

[0008] A communication method according to one aspect of the present disclosure includes a terminal receiving a carrier wave from each of a plurality of base stations that cooperate to transmit signals, controlling the receiving frequency of each of the carrier waves based on a reference signal contained in each of the carrier waves, and estimating the signal based on a decoding result of a decoding process in each of the carrier waves.

[0009] A base station according to one embodiment of the present disclosure has a receiving unit that receives carrier waves from each of a plurality of terminals, and a control unit that controls the receiving frequency of each of the carrier waves based on a reference signal included in each of the carrier waves, and estimates signals transmitted by the plurality of terminals based on a decoding result of a decoding process in each of the carrier waves.

[0010] A communication method according to one aspect of the present disclosure includes a base station receiving a carrier wave from each of a plurality of terminals, controlling the receiving frequency of each of the carrier waves based on a reference signal contained in each of the carrier waves, and estimating signals transmitted by the plurality of terminals based on a decoding result of a decoding process in each of the carrier waves. Effect of the Invention

[0011] According to the present disclosure, a terminal can properly receive signals transmitted in cooperation from multiple base stations. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating a configuration example of a wireless communication system according to an embodiment of the present disclosure. [Diagram 2] FIG. 13 is a diagram for explaining an example in which one frequency shift appears. [Diagram 3] FIG. 13 is a diagram illustrating an example in which multiple frequency shifts appear. [Figure 4] FIG. 2 is a diagram illustrating an example of functional blocks of a terminal. [Diagram 5] FIG. 2 illustrates an example of functional blocks of a base station. [Figure 6] 11 is a flowchart illustrating an operation example of a terminal. [Figure 7] FIG. 2 is a diagram illustrating an example of a hardware configuration of a terminal and a base station. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment according to one aspect of the present disclosure will be described with reference to the drawings.

[0014] Fig. 1 is a diagram showing a configuration example of a wireless communication system according to an embodiment of the present disclosure. As shown in Fig. 1, the wireless communication system includes a CU 1a, a DU 1b, wireless stations 1ca and 1cb, a mobile base station 2, and terminals 3 and 4. Note that CU stands for Centralized Unit. DU stands for Distributed Unit.

[0015] The CU1a includes, for example, an RRC layer, an SDAP layer, and a PDCP layer. RRC stands for Radio Resource Control. SDAP stands for Service Data Adaptation Protocol. PDCP stands for Packet Data Convergence Protocol.

[0016] DU1b has, for example, an RLC layer, a MAC layer, and a PHY-High layer. RLC is an abbreviation for Radio Link Control. MAC is an abbreviation for Medium Access Control. PHY is an abbreviation for physical.

[0017] The wireless stations 1ca and 1cb each have, for example, a PHY-Low & RF layer. RF is an abbreviation for Radio Frequency.

[0018] CU1a is connected to a core network (not shown) and DU1b. CU1a processes a signal received from the core network based on the above-mentioned layer function, and transmits the signal to DU1b. CU1a also processes a signal received from DU1b based on the above-mentioned layer function, and transmits the signal to the core network.

[0019] DU1b is connected to CU1a and wireless stations 1ca and 1cb. DU1b processes signals received from CU1a based on the above-mentioned layer functions and transmits the signals to wireless stations 1ca and 1cb. DU1b also processes signals received from wireless stations 1ca and 1cb based on the above-mentioned layer functions and transmits the signals to CU1a.

[0020] The wireless stations 1ca and 1cb are connected to the DU 1b. Moreover, the wireless stations 1ca and 1cb perform wireless communication with the terminals 3 and 4 using the millimeter wave band. The wireless stations 1ca and 1cb process signals received from the DU 1b based on the above-mentioned layer functions and transmit the signals to the terminals 3 and 4. Moreover, the wireless stations 1ca and 1cb process signals received from the terminals 3 and 4 based on the above-mentioned layer functions and transmit the signals to the DU 1a.

[0021] The configurations of the CU 1a, the DU 1b, and the wireless stations 1ca and 1cb are not limited to the example in Fig. 1. For example, one wireless station may be connected to the DU 1b, or three or more wireless stations may be connected to the DU 1b.

[0022] Also, one DU may be connected to each of the wireless stations 1ca and 1cb. The DU connected to the wireless station 1ca and the DU connected to the wireless station 1cb may be connected to the CU 1a.

[0023] Furthermore, the wireless stations 1ca and 1cb may be cascade-connected. For example, the wireless station 1ca may be connected to the DU 1b, and the wireless station 1cb may be connected to the wireless station 1ca.

[0024] Also, CU1a and DU1b may be referred to as a base station, a gNB, a fixed base station, or a ground station. Also, CU1a, DU1b, and the radio stations 1ca and 1cb may be referred to as a base station, a fixed base station, or a ground station. The radio station may be referred to as an RU (Radio Unit), a base station, a transmission point, or an antenna panel. Hereinafter, CU1a, DU1b, and the radio stations 1ca and 1cb may be referred to as a fixed base station 1.

[0025] The mobile base station 2 is a mobile base station such as a drone or a High Altitude Platform Station (HAPS). The mobile base station 2 does not have to move in the air, and may be a vehicle that moves on the ground, such as an automobile or a train. The mobile base station 2 performs wireless communication with the terminal 4 using the millimeter wave band.

[0026] The terminal 3 is a terminal that relays communication between the fixed base station 1 and the terminal 4. The communication between the terminal 4 and the fixed base station 1 via the terminal 3 may be referred to as terminal-to-terminal cooperative communication or sidelink communication. The terminal 3 performs wireless communication with the terminal 4 using the millimeter wave band. From the perspective of the terminal 4, the terminal 3 can be regarded as a base station, a mobile base station, or a relay station.

[0027] Fixed base station 1, mobile base station 2, and terminal 3 communicate with terminal 4 in cooperation. For example, as shown in FIG. 1, fixed base station 1 communicates with terminal 4 using stream #0. Mobile base station 2 communicates with terminal 4 using stream #1. Terminal 3 communicates with terminal 4 using stream #2.

[0028] Cooperative communication based on multiple base stations includes, for example, cooperative transmission in which the same signal is transmitted to a terminal 4, distributed MIMO in which different signals are transmitted to a terminal 4, and communication switching in which a base station transmitting a signal is switched. Cooperative transmission may be referred to as simultaneous transmission, cooperative MIMO, or joint transmission. Distributed MIMO may be referred to as distributed transmission or distributed transmission.

[0029] When the terminal 4 moves, a frequency shift may occur in the carrier wave received by the terminal 4. For example, a Doppler frequency shift may occur in the carrier wave received by the terminal 4.

[0030] Fig. 2 is a diagram for explaining an example in which one frequency shift appears. In the explanation of Fig. 2, it is assumed that the fixed base station 1 outputs a carrier wave, and the mobile base station 2 and the terminal 3 do not output a carrier wave.

[0031] 2 indicates the frequency (center frequency) of the carrier wave of the fixed base station 1. "fc+Δf1" shown in Fig. 2 indicates the frequency (reception frequency) of the carrier wave received by the terminal 4.

[0032] The carrier wave of the fixed base station 1 may have a shifted frequency when it is received by the terminal 4. For example, the received frequency of the carrier wave at the terminal 4 may shift from "fc" to "fc+Δf1" as shown in FIG.

[0033] The signal received by the terminal 4 may contain an error due to a deviation in the receiving frequency of the carrier wave. Therefore, the terminal 4 compensates (corrects) the receiving frequency of the carrier wave using AFC (Automatic Frequency Control).

[0034] For example, the AFC calculates the phase rotation of the reference signal based on the reference signal transmitted from the fixed base station 1. The AFC calculates the deviation "Δf1" of the receiving frequency of the carrier based on the calculated phase rotation. The AFC adjusts the receiving frequency of the carrier to "fc+Δf1" based on the calculated "Δf1" and receives the carrier. For example, DMRS (DeModulation Reference Signals) may be used as the reference signal.

[0035] In the above, it has been described that the mobile base station 2 and the terminal 3 do not output carrier waves, but they may output carrier waves. Even if the fixed base station 1, the mobile base station 2, and the terminal 3 output carrier waves, if the carrier wave shifts of the fixed base station 1, the mobile base station 2, and the terminal 3 are the same, one carrier wave shift (Δf1) appears as shown in Fig. 2. In this case, the terminal 4 also compensates for the receiving frequency of the carrier wave using AFC.

[0036] Fig. 3 is a diagram for explaining an example in which a plurality of frequency shifts appear. In the explanation of Fig. 3, it is assumed that the fixed base station 1 and the mobile base station 2 output a carrier wave, and the terminal 3 does not output a carrier wave.

[0037] "fc" in Fig. 3 indicates the frequency of the carrier waves of the fixed base station 1 and the mobile base station 2. "fc+Δf1" in Fig. 3 indicates the reception frequency of the carrier wave of the fixed base station 1 received by the terminal 4. "fc+Δf2" in Fig. 3 indicates the reception frequency of the carrier wave of the mobile base station 2 received by the terminal 4.

[0038] The carrier waves of the fixed base station 1 and the mobile base station 2 may have a frequency shift when received by the terminal 4. For example, the received frequency of the carrier wave at the terminal 4 may shift from "fc" to "fc+Δf1" or "fc+Δf2" as shown in FIG.

[0039] For example, when LOS (Line Of Sigh) communication is performed and there is no reflected wave, the carrier shift appears at most as many as the number of base stations with which the terminal 4 is communicating.

[0040] For example, when the fixed base station 1 and the mobile base station 2 transmit carrier waves, a maximum of two receiving frequency deviations occur in the terminal 4 as shown in Fig. 3. Also, for example, when the fixed base station 1, the mobile base station 2, and the terminal 3 transmit carrier waves, a maximum of three receiving frequency deviations occur in the terminal 4.

[0041] That is, in communication based on base station cooperation, carrier waves arrive at terminal 4 from multiple base stations (multiple directions), resulting in multiple frequency shifts. Therefore, it is important to compensate for the receiving frequency of the carrier waves based on the multiple frequency shifts that occur when terminal 4 moves. In particular, when a wireless communication system includes a mobile base station 2 and a moving terminal 3, a large frequency shift may occur, making it important to compensate for the receiving frequency of the carrier waves. Also, it is important to estimate the transmission signal after compensating for the receiving frequency of the carrier waves.

[0042] <Frequency shift compensation processing and transmission signal estimation processing> The terminal 4 compensates for a plurality of frequency shifts of the carrier wave based on base station cooperation by the following processes 1 to 3. Then, the terminal 4 estimates a transmission signal transmitted by the base station through base station cooperation.

[0043] 1. The receiving frequency of the carrier is adjusted to one of multiple frequency shift positions and the receiving process is performed. For example, in the example of Fig. 3, the AFC of terminal 4 tunes the receiving frequency of the carrier wave to "fc+Δf1" out of the frequency shift positions "fc+Δf1" and "fc+Δf2". After tuning the receiving frequency of the carrier wave to "fc+Δf1", terminal 4 performs receiving processing of the transmission signals transmitted by the fixed base station 1 and the mobile base station 2. For example, terminal 4 performs demodulation and decoding processing of the transmission signals transmitted by the fixed base station 1 and the mobile base station 2.

[0044] 2. The receiving frequency of the carrier is adjusted to a different frequency shift position from that of 1. above. For example, in the example of Fig. 3, the AFC of terminal 4 adjusts the receiving frequency of the carrier wave to "fc+Δf2", which is different from "fc+Δf1" adjusted in 1, out of the frequency shift positions "fc+Δf1" and "fc+Δf2". After adjusting the receiving frequency of the carrier wave to "fc+Δf2", terminal 4 performs receiving processing of the transmission signals transmitted by the fixed base station 1 and the mobile base station 2. For example, terminal 4 performs demodulation and decoding processing of the transmission signals transmitted by the fixed base station 1 and the mobile base station 2.

[0045] 3. Using the results of the reception processing in steps 1 and 2 above, estimate the transmitted signal. The terminal 4 uses (combines) the reception processing results (signals after demodulation and decoding) of 1. and 2. above to estimate the transmission signals included in the carrier waves transmitted by the fixed base station 1 and the mobile base station 2. For example, the terminal 4 estimates the transmission signals transmitted by the fixed base station 1 and the mobile base station 2 using cooperative transmission or distributed MIMO based on maximum ratio combining of the soft values ​​of the reception processing results obtained in 1. above and the soft values ​​of the reception processing results obtained in 2. above. Alternatively, the terminal 4 estimates the transmission signals transmitted by the fixed base station 1 and the mobile base station 2 using cooperative transmission or distributed MIMO based on a majority vote of the hard values ​​of the reception processing results obtained in 1. above and the hard values ​​of the reception processing results obtained in 2. above.

[0046] That is, the terminal 4 compensates the receiving frequency of the receiving carrier wave for each of a plurality of frequency shifts using AFC. The terminal 4 performs receiving processing of the transmission signal cooperatively transmitted by the fixed base station 1 and the mobile base station 2 at each receiving frequency of the compensated carrier wave. Then, the terminal 4 estimates the transmission signal transmitted by the fixed base station 1 and the mobile base station 2 using the receiving processing result at each receiving frequency of the compensated carrier wave.

[0047] Although the AFC is used for the compensation process for the frequency shift of the received carrier wave, the compensation process is not limited to this, and other processes may be used for the compensation process for the frequency shift.

[0048] Furthermore, the reception processing at different frequency shift positions is not limited to being performed twice as in the examples of 1 and 2. Terminal 4 repeats the processing of 1 and 2 according to the number of frequency shifts.

[0049] For example, assume that three base stations transmit carrier waves, and three frequency shifts occur in terminal 4: "Δf1, Δf2, Δf3." In this case, terminal 4 compensates the receiving frequency of the carrier wave at Δf1 (compensates the receiving frequency to fc+Δf1) and performs receiving processing. Next, the terminal compensates the receiving frequency of the carrier wave at Δf2, which is different from Δf1 (compensates the receiving frequency to fc+Δf2) and performs receiving processing. Next, the terminal compensates the receiving frequency of the carrier wave at Δf3, which is different from Δf1 and Δf2 (compensates the receiving frequency to fc+Δf3) and performs receiving processing. Then, terminal 4 estimates the transmission signals transmitted by the three base stations using each receiving processing result.

[0050] Furthermore, terminal 4 may use the reception processing result obtained in the reception processing of 1 above for the reception processing of 2 above. For example, terminal 4 may use the reception processing result obtained in the reception processing of 1 above for interference cancellation in the reception processing of 2 above. In other words, terminal 4 may use the reception processing result obtained in one reception processing for another reception processing.

[0051] The reception processes of 1 and 2 may be performed by a single circuit. For example, a single circuit may perform the reception process of 1 and then the reception process of 2.

[0052] Furthermore, the reception processes of 1. and 2. above may be executed by two circuits. For example, a first circuit may execute the reception process of 1. above, and a second circuit may execute the reception process of 1. above. The reception process of the first circuit and the reception process of the second circuit may overlap in processing timing. Furthermore, the first circuit may be composed of multiple circuits. The second circuit may also be composed of multiple circuits.

[0053] Although the above describes the reception processing in the downlink, the above processes 1 to 3 may be applied to the reception processing in the uplink. For example, each of the fixed base station 1, the mobile base station 2, and the terminal 3 may execute the above processes 1 to 3 for signals transmitted from multiple terminals.

[0054] In the uplink direction, the fixed base station 1 may divide the antenna element group of the wireless stations 1ca and 1cb into multiple blocks, and perform the reception process of 1. and the reception process of 2. above in each block. The reception process corresponding to each block may be performed by one circuit. For example, the antenna element group of 128 elements provided in the wireless station 1ca may be divided into a first block of 64 elements and a second block of 64 elements. The reception process in the first block may be performed by a first circuit, and the reception process in the second block may be performed by a second circuit.

[0055] <Frequency shift compensation process using position information> The terminal 4 may compensate for the frequency shift of the carrier wave transmitted by each of the base stations, using the location information of each of the fixed base station 1, the mobile base station 2, and the terminal 3 that perform base station cooperation, and the location information of the terminal 4. After performing the compensation process for the frequency shift of the carrier wave using the location information, the terminal 4 may execute the receiving process of 1. and 2. above.

[0056] For example, terminal 4 calculates the relative angle between fixed base station 1 and terminal 4 based on the location information of fixed base station 1 and the location information of terminal 4. Terminal 4 calculates (estimates) the frequency shift (amount) of the carrier wave transmitted by fixed base station 1 from the calculated relative angle. Terminal 4 compensates the receiving frequency of the carrier wave of fixed base station 1 based on the calculated frequency shift. Terminal 4 executes the AFC in 1 above using the receiving frequency of the compensated carrier wave (from the position of the receiving frequency of the compensated carrier wave). This allows terminal 4 to shorten the processing time (AFC processing time) of 1 above.

[0057] Also, for example, terminal 4 calculates the relative angle between mobile base station 2 and terminal 4 based on the location information of mobile base station 2 and the location information of terminal 4. Terminal 4 calculates (estimates) the frequency shift of the carrier wave transmitted by mobile base station 2 from the calculated relative angle. Terminal 4 compensates the receiving frequency of the carrier wave of mobile base station 2 based on the calculated frequency shift. Terminal 4 executes AFC in 2 above using the receiving frequency of the compensated carrier wave (from the position of the receiving frequency of the compensated carrier wave). This allows terminal 4 to shorten the processing time of 2 above (the processing time of AFC).

[0058] The fixed base station 1 transmits, for example, location information preset in the fixed base station 1 to the terminal 4. The mobile base station 2 has a location acquisition function such as GPS, and transmits the location information of the mobile base station 2 to the terminal 4. The terminal 4 has a location acquisition function such as GPS, and acquires the location information of the terminal 4. The terminal 4 calculates the relative angle between the terminal 4 and the fixed base station 1 using the location information transmitted from the fixed base station 1 and the location information of the terminal 4 acquired by the location acquisition function of the terminal 4. The terminal 4 also calculates the relative angle between the terminal 4 and the mobile base station 2 using the location information transmitted from the mobile base station 2 and the location information of the terminal 4 acquired by the location acquisition function of the terminal 4.

[0059] In the above example, terminal 4 compensates for the frequency shifts in two base stations, fixed base station 1 and mobile base station 2, based on location information, but this is not limited to the above. When three base stations, fixed base station 1, mobile base station 2, and terminal 3, cooperate with each other, terminal 4 also compensates for the frequency shift of terminal 3 based on location information transmitted from terminal 3 and location information of terminal 4. Then, terminal 4 executes AFC of the receiving carrier of terminal 3 using the receiving frequency of the carrier compensated based on the location information, and performs receiving processing of the transmission signal transmitted by terminal 3.

[0060] Furthermore, the fixed base station 1 may calculate (estimate) the deviation (phase rotation (amount)) of the frequency shift of the carrier wave received by the terminal 4, and apply the calculated phase rotation (amount) to the carrier wave to be transmitted to the terminal 4.

[0061] For example, the fixed base station 1 receives location information from the terminal 4. The fixed base station 1 calculates the phase rotation of the carrier wave received at the terminal 4 using the location information of the fixed base station 1 and the location information received from the terminal 4. The fixed base station 1 applies the calculated phase rotation to the carrier wave to be transmitted to the terminal 4 and transmits it to the terminal 4. This eliminates the need for the terminal 4 to perform compensation processing for the frequency shift based on the location information, thereby reducing processing overhead. Note that the mobile base station 2 and the terminal 3 also apply phase rotation to the carrier wave to be transmitted to the terminal 4 in the same manner.

[0062] In the above example, an example of frequency shift compensation processing using location information in the downlink direction has been described, but the frequency shift compensation processing using location information may be applied to reception processing in the uplink direction. For example, each of the fixed base station 1, the mobile base station 2, and the terminal 3 may compensate the frequency of the received carrier wave using location information for carrier waves transmitted from multiple terminals. Then, each of the fixed base station 1, the mobile base station 2, and the terminal 3 may execute the above-mentioned processes 1. to 3.

[0063] 4 is a diagram showing an example of functional blocks of the terminal 4. The terminal 4 includes a communication unit 11 and a control unit 12.

[0064] The communication unit 11 receives carrier waves from each of a plurality of base stations that cooperate to transmit signals.

[0065] The control unit 12 controls the reception frequency of each carrier based on a reference signal included in each carrier. For example, the control unit 12 controls the reception frequency of each carrier using AFC. Then, the control unit 12 performs demodulation and decoding processing on each carrier, and estimates signals transmitted by multiple base stations based on the processing results of the demodulation and decoding processing.

[0066] Furthermore, the control unit 12 calculates the amount of frequency shift for each carrier wave based on the location information of each of the multiple base stations and the location information of the terminal 4. The control unit 12 controls the receiving frequency of each carrier wave based on the calculated amount of frequency shift, and then controls the receiving frequency of each carrier wave based on a reference signal.

[0067] 5 is a diagram showing an example of functional blocks of the base station 20. In the following, when there is no need to distinguish between the fixed base station 1, the mobile base station 2, and the terminal 3, they will be referred to as the base station 20.

[0068] The communication unit 21 receives a carrier wave from each of a plurality of terminals.

[0069] The control unit 22 controls the reception frequency of each carrier based on a reference signal included in each carrier. For example, the control unit 22 controls the reception frequency of each carrier using AFC. Then, the control unit 22 performs demodulation and decoding processing on each carrier, and estimates signals transmitted by multiple terminals based on the processing results of the demodulation and decoding processing.

[0070] Furthermore, the control unit 22 calculates the amount of frequency shift for each carrier wave based on the location information of each of the multiple terminals and the location information of the base station 20. The control unit 22 controls the receiving frequency of each carrier wave based on the calculated amount of frequency shift, and then controls the receiving frequency of each carrier wave based on a reference signal.

[0071] Fig. 6 is a flowchart illustrating an example of the operation of the terminal 4. The terminal 4, for example, repeatedly executes the process of the flowchart shown in Fig. 6. Hereinafter, the processes described in 1. to 3. above will be referred to as "repeated reception process."

[0072] The terminal 4 estimates the frequency shift of the carrier wave based on a reference signal included in the carrier wave transmitted from the base station 20 (S1).

[0073] Terminal 4 determines whether the number of frequency shifts estimated in S1 is two or more (S2).

[0074] If the terminal 4 determines that the number of frequency shifts is not two or more (No in S2), that is, if the number of frequency shifts is one as described in FIG. 2, it compensates the receiving frequency of the carrier based on AFC and estimates the transmission signal of the base station 20 (S9).

[0075] On the other hand, when the terminal 4 determines that the number of frequency shifts is two or more (Yes in S2), that is, when the number of frequency shifts is two or more as described in FIG. 3, the terminal 4 determines whether or not it is possible to perform repeated reception processing (whether or not it has a repeated reception processing function) (S3).

[0076] When the terminal 4 determines that repeated reception processing is possible (Yes in S3), it determines whether or not compensation processing for the reception frequency of the carrier wave is possible using the location information of the terminal 4 and the location information of the base station 20 (whether or not it has a compensation processing function for frequency shift using location information) (S4).

[0077] When the terminal 4 determines that compensation processing of the receiving frequency of the carrier wave is possible using the location information of the terminal 4 and the location information of the base station 20 (Yes in S4), the terminal 4 executes compensation processing of the receiving frequency of the carrier wave using the location information of the terminal 4 and the location information of the base station 20, and executes repetitive reception processing (S5). For example, the terminal 4 executes compensation processing of the receiving frequency of the carrier wave using the location information of the terminal 4 and the location information of the base station 20, and executes AFC in the repetitive reception processing from the receiving frequency position of the compensated carrier wave.

[0078] On the other hand, if the terminal 4 determines that compensation processing for the receiving frequency of the carrier wave is not possible using the location information of the terminal 4 and the location information of the base station 20 (No in S4), it does not perform compensation processing for the receiving frequency of the carrier wave using the location information of the terminal 4 and the location information of the base station 20, and repeatedly performs the receiving processing (S6).

[0079] If terminal 4 determines in S3 that repeated reception processing is not possible (No in S3), it determines whether compensation processing of the carrier reception frequency is possible using the location information of terminal 4 and the location information of base station 20 (S7).

[0080] When the terminal 4 determines that the compensation process for the receiving frequency of the carrier wave is possible using the location information of the terminal 4 and the location information of the base station 20 (Yes in S7), the terminal 4 executes the compensation process for the receiving frequency of the carrier wave using the location information of the terminal 4 and the location information of the base station 20 (S8). Then, after the compensation process for the receiving frequency of the carrier wave is executed, the terminal 4 estimates the transmission signal of the base station 20.

[0081] On the other hand, if the terminal 4 determines that compensation processing of the receiving frequency of the carrier wave is not possible using the location information of the terminal 4 and the location information of the base station 20 (No in S7), it performs AFC processing of the receiving frequency of the carrier wave and estimates the transmission signal of the base station 20 (S9).

[0082] If the terminal 4 does not have a compensation processing function for the receiving frequency of the carrier wave based on the location information, the base station 20 may calculate the phase rotation of the receiving carrier wave of the terminal 4 based on the location information of the base station 20 and the location information of the terminal 4. Then, the base station 20 may apply the calculated phase rotation to the carrier wave and transmit it to the terminal 4.

[0083] Also, in FIG. 6, an example of the operation of the terminal 4 has been described, but the base station 20 may also execute the same operation.

[0084] As described above, the terminal 4 includes the communication unit 11 that receives carrier waves from each of the multiple base stations that transmit signals in cooperation with each other, and the control unit 12 that controls the reception frequency of each carrier wave based on a reference signal included in the carrier wave and estimates signals transmitted by the multiple base stations based on the decoding results of the decoding process in each carrier wave. This allows the terminal 4 to properly receive signals transmitted by the multiple base stations in cooperation with each other.

[0085] For example, the control unit 12 controls the receiving frequency of each carrier wave based on a reference signal contained in the carrier wave, and estimates signals transmitted by multiple base stations based on the decoding results for each carrier wave. Therefore, even if a frequency shift occurs in each of the carrier waves transmitted by the multiple base stations, signals transmitted in cooperation from the multiple base stations can be properly received.

[0086] The base station 20 also includes a communication unit 21 that receives carrier waves from each of a plurality of terminals that transmit signals, and a control unit 22 that controls the reception frequency of each carrier wave based on a reference signal included in the carrier wave and estimates the signals transmitted by the plurality of terminals based on the decoding results of the decoding process in each carrier wave. This allows the base station 20 to properly receive signals transmitted by the plurality of terminals.

[0087] For example, the control unit 22 controls the receiving frequency of each carrier based on a reference signal contained in the carrier, and estimates the signals transmitted by the multiple terminals based on the decoding results in each carrier. Therefore, even if a frequency shift occurs in each of the carriers transmitted by the multiple terminals, the signals transmitted by the multiple terminals can be properly received.

[0088] The present disclosure has been described above.

[0089] <Hardware configuration, etc.> The block diagrams used to explain 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 by using one device that is physically or logically combined, or may be realized by using two or more devices that are physically or logically separated and directly or indirectly connected (for example, by wire, wirelessly, etc.). The functional blocks may be realized by combining the one device or the multiple devices with software.

[0090] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, selection, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocation, mapping, assignment, etc. For example, a functional block (component) that performs the function of transmission is called a transmitting unit or a transmitter. In either case, as described above, there is no particular limitation on the method of realization.

[0091] For example, the terminal 4 and the base station 20 in the embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 7 is a diagram showing an example of a hardware configuration of the terminal 4 and the base station 20. Each of the terminal 4 and the base station 20 described above may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input unit 1005, an output unit 1006, a bus 1007, etc.

[0092] In the following description, the term "apparatus" can be interpreted as a circuit, a device, a unit, etc. The hardware configuration of the terminal 4 and the base station 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.

[0093] Each function of the terminal 4 and the base station 20 is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and the memory 1002, causing the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of reading and writing of data in the memory 1002 and the storage 1003. The functions of the modules A, B, and C may be realized by the processor 1001.

[0094] The processor 1001 controls the entire computer by running, for example, an operating system. The processor 1001 may be configured with a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic unit, a register, and the like.

[0095] Moreover, the processor 1001 reads out a program (program code), a software module, data, etc. from at least one of the storage 1003 and the communication device 1004 into the memory 1002, and executes various processes according to the programs. As the programs, programs that cause a computer to execute at least a part of the operations described in the above-mentioned embodiments are used. For example, the functions of the control units 12 and 22 may be realized by a control program stored in the memory 1002 and operated in the processor 1001, and may be similarly realized for other functional blocks. 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 programs may be transmitted from a network via a telecommunication line.

[0096] The memory 1002 is a computer-readable recording medium, and may be configured by at least one of, for example, a Read Only Memory (ROM), an Erasable Programmable ROM (EPROM), an Electrically Erasable Programmable ROM (EEPROM), a Random Access Memory (RAM), etc. The memory 1002 may be called a register, a cache, a main memory (primary storage device), etc. The memory 1002 can store a program (program code), software modules, etc. that are executable to implement a wireless communication method according to an embodiment of the present disclosure.

[0097] Storage 1003 is a computer-readable recording medium, and may be composed of at least one of, for example, 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, and the like. Storage 1003 may be referred to as an auxiliary storage device. The above-mentioned storage medium may be, for example, a database, a server, or other suitable medium including at least one of memory 1002 and storage 1003.

[0098] The communication device 1004 is hardware (transmission / reception device) for performing communication 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., in order to realize at least one of Frequency Division Duplex (FDD) and Time Division Duplex (TDD). The communication units 11 and 21 may be realized by the communication device 1004. Each of the communication units 11 and 21 may have a transmission unit that transmits a signal and a reception unit that receives a signal.

[0099] An input device (e.g., a key device, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts input from the outside and an operation device (e.g., a dial) are connected to the input unit 1005. An output device (e.g., a display, a speaker, an LED lamp, etc.) is connected to the output unit 1006. The input device and the output device connected to the input unit 1005 and the output unit 1006 may be an integrated device (e.g., a touch panel).

[0100] In addition, each device such as the processor 1001 and the memory 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.

[0101] Furthermore, the terminal 4 and the base station 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), and 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.

[0102] <Information notification, signaling> 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. 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, or the like.

[0103] <Applicable systems> Each aspect / embodiment described in the present disclosure may be applied to at least one of systems using LTE (Long Term Evolution), LTE-A (LTE-Advanced), 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), and other suitable systems, and next-generation systems extended based on these. In addition, a combination of multiple systems (e.g., a combination of at least one of LTE and LTE-A and 5G, etc.) may be applied.

[0104] <Processing procedures, etc.> The order of the steps, sequences, flow charts, etc. of each aspect / embodiment described in this disclosure may be changed 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.

[0105] <Base station operation> In the present disclosure, a specific operation performed by a base station may be performed by its upper node in some cases. In a network consisting of one or more network nodes having a base station, it is clear that various operations performed for communication with a terminal may be performed by at least one of the base station and other network nodes other than the base station (e.g., MME or S-GW, etc., but are not limited to these). Although the above example illustrates a case in which there is one other network node other than the base station, it may also be a combination of multiple other network nodes (e.g., MME and S-GW).

[0106] <Input / output direction> Information, etc. (see the "Information, Signals" section) may be output from a higher layer (or a lower layer) to a lower layer (or a higher layer). It may also be input / output via multiple network nodes.

[0107] <Handling of input and output information, etc.> 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 transmitted to another device.

[0108] <Judgment method> The determination may be based on a value represented by a single bit (0 or 1), a Boolean value (true or false), or a numerical comparison (e.g., comparison with a predetermined value).

[0109] <Variations in form, etc.> Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched according to 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).

[0110] 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 in the present disclosure. 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.

[0111] <Software> 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.

[0112] Additionally, software, instructions, information, etc. may be transmitted or received over a transmission medium. For example, if the software is transmitted from a website, server, or other remote source using wired and / or wireless technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL)), and / or wireless technologies (such as infrared, microwave, etc.), then these wired and / or wireless technologies are included within the definition of transmission media.

[0113] <Information, Signals> 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.

[0114] In addition, 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 a channel and a symbol may be a signal (signaling). Also, a signal may be a message. Also, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0115] <System, Network> As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0116] <Parameter, channel name> In addition, the information, parameters, etc. described in the present 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.

[0117] The names used for the above-mentioned parameters are not limiting in any way. Moreover, the formulas 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.

[0118] <Base station> In this disclosure, terms such as "base station (BS)", "radio base station", "fixed station", "NodeB", "eNodeB (eNB)", "gNodeB (gNB)", "access point", "transmission point", "reception point", "transmission / reception point", "cell", "sector", "cell group", "carrier", "component carrier", etc. may be used interchangeably. A base station may also be referred to by terms such as a macro cell, a small cell, a femto cell, a pico cell, etc.

[0119] 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 be provided with 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 ​​a base station and / or a base station subsystem that provides communication services in this coverage.

[0120] <Mobile Station> In this disclosure, the terms "Mobile Station (MS)", "user terminal", "User Equipment (UE)", "terminal", etc. may be used interchangeably.

[0121] 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.

[0122] <Base station / mobile station> 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.

[0123] 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 a plurality of user terminals (which may be called, for example, D2D (Device-to-Device) or V2X (Vehicle-to-Everything)). In this case, the user terminal may be configured to have the functions of the above-mentioned base station. Furthermore, terms such as "uplink" and "downlink" may be read as terms corresponding to terminal-to-terminal communication (for example, "side"). For example, an uplink channel, a downlink channel, etc. may be read as a side channel.

[0124] Similarly, a user terminal in the present disclosure may be read as a base station. In this case, the base station may be configured to have the functions of the above-mentioned user terminal.

[0125] <Terminology and interpretation> 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), 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 a 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." In addition, "judgment" can be interpreted as "assuming," "expecting," "considering," etc.

[0126] 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.

[0127] <Reference signal> The reference signal may be abbreviated as RS (Reference Signal) and may be called a pilot depending on the applicable standard.

[0128] <The meaning of "based on"> 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."

[0129] <"First", "Second"> 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.

[0130] <“Means”> In the configurations of each of the above-described apparatuses, the "means" may be replaced with a "section", "circuit", "device", or the like.

[0131] <Open format> In the present disclosure, when the terms "include", "including", and their variants are used, these terms are intended to be inclusive, similar to the term "comprising". Further, the term "or" used in the present disclosure is not intended to be an exclusive disjunction.

[0132] <Time units such as TTI, frequency units such as RB, radio frame configuration> A radio frame may be composed of one or more frames in the time domain. In the time domain, each of one or more frames may be referred to as a subframe.

[0133] A subframe may further be composed of one or more slots in the time domain. A subframe may have a fixed time duration (e.g., 1 ms) that does not depend on numerology.

[0134] Numerology may be a communication parameter applied to at least one of transmission and reception of a certain signal or channel. Numerology may indicate, for example, at least one of subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering processing performed by a transceiver in the frequency domain, and specific windowing processing performed by a transceiver in the time domain.

[0135] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol, a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol, etc.) in the time domain. A slot may be a time unit based on numerology.

[0136] A slot may include multiple minislots. Each minislot may be composed of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may be composed 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.

[0137] A radio frame, a subframe, a slot, a minislot, and a symbol each represent a time unit for transmitting a signal. The radio frame, the subframe, the slot, the minislot, and the symbol may each be referred to by a different name.

[0138] 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. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in the existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit expressing the TTI may be called a slot, a minislot, or the like, instead of a subframe.

[0139] Here, TTI refers to, for example, the minimum time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. Note that the definition of TTI is not limited to this.

[0140] The TTI may be a transmission time unit for a channel-encoded 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. are actually mapped may be shorter than the TTI.

[0141] In addition, when one slot or one minislot is called TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit of scheduling. Also, the number of slots (minislots) constituting the minimum time unit of scheduling may be controlled.

[0142] A TTI having a time length of 1 ms may be called a normal TTI (TTI in LTE Rel. 8-12), a normal TTI, a long TTI, a normal subframe, a normal subframe, a long subframe, a slot, etc. A TTI shorter than a normal TTI may be called a shortened TTI, a short TTI, a partial or fractional TTI, a shortened subframe, a short subframe, a minislot, a subslot, a slot, etc.

[0143] In addition, 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 shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0144] A resource block (RB) is a resource allocation unit in the time domain and the 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.

[0145] In addition, the time domain of the RB may include one or more symbols and may be one slot, one minislot, one subframe, or one TTI in length. Each of one TTI, one subframe, etc. may be composed of one or more resource blocks.

[0146] Note that one or more RBs may be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, or the like.

[0147] Furthermore, a resource block may 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.

[0148] A Bandwidth Part (BWP), which may also be referred to as a fractional bandwidth, may represent a subset of contiguous common resource blocks (RBs) for a numerology on a carrier, where the common RBs may be identified by the index of the RBs relative to a common reference point of the carrier. PRBs may be defined in a BWP and numbered within the BWP.

[0149] 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.

[0150] 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 replaced with "BWP".

[0151] The above-mentioned structures of radio frames, subframes, slots, minislots, symbols, etc. 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, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0152] <Maximum transmission power> The "maximum transmit power" in this disclosure may mean the maximum value of transmit power, may mean the nominal UE maximum transmit power, or may mean the rated UE maximum transmit power.

[0153] <Article> In this disclosure, where articles have been added due to translation, such as, for example, a, an, and the in English, the disclosure may include that the nouns following these articles are in the plural form.

[0154] <"Different"> In the present 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 "coupled" may also be interpreted in the same way as "different." [Industrial Applicability]

[0155] The present disclosure is useful in wireless systems. [Explanation of symbols]

[0156] 1 Fixed base station 1a CU 1b DU 1ca,1cb wireless station 2 Mobile base station 3,4 Devices 11,21 Communications Department 12,22 Control section 20 base station

Claims

1. a receiving unit for receiving a carrier wave from each of a plurality of base stations which cooperate to transmit signals; a control unit that controls a reception frequency of each of the carriers based on a reference signal included in each of the carriers, and estimates the signal based on a decoding result of a decoding process in each of the carriers; having The control unit controls a reception frequency of each of the carriers based on a frequency shift amount of each of the carriers obtained from location information of each of the plurality of base stations and location information of a terminal, and then controls a reception frequency of each of the carriers based on the reference signal. Terminal.

2. The device is receiving a carrier wave from each of a plurality of base stations which cooperate to transmit a signal; Controlling the reception frequency of each of the carrier waves based on a reference signal included in each of the carrier waves; A communication method for estimating the signal based on a decoding result of a decoding process for each of the carriers, comprising: The control includes controlling a reception frequency of each of the carriers based on a frequency shift amount of each of the carriers obtained from location information of each of the plurality of base stations and location information of the terminal, and then controlling the reception frequency of each of the carriers based on the reference signal. Communication methods.

3. A receiving unit that receives a carrier wave from each of a plurality of terminals; a control unit that controls a reception frequency of each of the carriers based on a reference signal included in each of the carriers, and estimates signals transmitted by the plurality of terminals based on a decoding result of a decoding process in each of the carriers; having The control unit controls a reception frequency of each of the carriers based on a frequency shift amount of each of the carriers obtained from location information of each of the plurality of terminals and location information of a base station, and then controls a reception frequency of each of the carriers based on the reference signal. Base station.

4. The base station Receive a carrier wave from each of a plurality of terminals; Controlling the reception frequency of each of the carrier waves based on a reference signal included in each of the carrier waves; A communication method for estimating signals transmitted by the plurality of terminals based on a decoding result of a decoding process for each of the carriers, comprising: The control includes controlling a reception frequency of each of the carriers based on a frequency shift amount of each of the carriers obtained from location information of each of the plurality of terminals and location information of the base station, and then controlling the reception frequency of each of the carriers based on the reference signal. Communication methods.

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