Transmitting device, transmitting method, and integrated circuit

Abstract

To provide a transmitting device capable of properly positioning reference signals.SOLUTION: The transmitting device includes: a control circuit that determines the arrangement of the second reference signal in the second system based on the placement of the first reference signal in the first system; and a transmission circuit that transmits a second reference signal based on the determined placement. The control circuit is configured so as to, when the position of at least one reference signal is changed in the multiple second reference signals, change the position of the remaining reference signals.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present disclosure relates to a receiving device, a transmitting device, a receiving method, and a transmitting method. [Background technology]

[0002] A communication system called the fifth generation mobile communication system (5G) is being considered. The 3rd Generation Partnership Project (3GPP), an international standardization organization, is considering the advancement of the 5G communication system from the perspectives of both the advancement of the LTE / LTE-Advanced system and New Radio Access Technology (also called New RAT or NR), which is a new method that does not necessarily have backward compatibility with the LTE / LTE-Advanced system (for example, see Non-Patent Document 1).

[0003] In NR, technologies (e.g., Dynamic Spectrum Sharing: DSS) that allow an NR system and an LTE system to coexist and communicate simultaneously in the same frequency band are being considered (e.g., see Non-Patent Document 2). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] RP-181726, "Revised WID on New Radio Access Technology", NTT DOCOMO, September 2018 [Non-Patent Document 2] RP-191042, "Enhancements for dynamic spectrum sharing in Rel-16", Ericsson, June 2019 [Non-Patent Document 3] RP-191599, "Enhancements for dynamic spectrum sharing in Rel-16", Ericsson, June 2019 [Non-Patent Document 4] 3GPP TS 38.211 V15.6.0, "NR; Physical channels and modulation (Release 15)," 2019-06 [Non-Patent Document 5] 3GPP TS 38.331 V15.6.0, "NR; Radio Resource Control (RRC) protocol specification (Release 15)," 2019-06 [Non-Patent Document 6] 3GPP TS 38.214 V15.6.0, "NR; Physical layer procedures for data (Release 15)," 2019-06 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the method of allocating reference signals has not been fully considered.

[0006] Non-limiting embodiments of the present disclosure contribute to providing a receiving device, a transmitting device, a receiving method, and a transmitting method that can appropriately allocate reference signals. [Means for solving the problem]

[0007] A receiving device according to one embodiment of the present disclosure includes a control circuit that determines an arrangement of a second reference signal in a second system based on information capable of identifying an arrangement of a first reference signal in a first system, and a receiving circuit that receives the second reference signal based on the determined arrangement.

[0008] These comprehensive or specific aspects may be realized as a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized as any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. Effect of the Invention

[0009] According to an embodiment of the present disclosure, reference signals can be appropriately arranged.

[0010] Further advantages and benefits of an embodiment of the present disclosure will become apparent from the specification and drawings. Such advantages and / or benefits may be provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of them may be provided to obtain one or more identical features. [Brief description of the drawings]

[0011] [Figure 1] A diagram showing an example of a DSS [Diagram 2] A diagram showing an example of PDSCH mapping type B [Diagram 3] Block diagram showing an example of CRS deployment [Figure 4] A diagram showing an example of orthogonal DMRS based MU-MIMO and DSS [Diagram 5] A block diagram showing an example of the configuration of a portion of a base station. [Figure 6] A block diagram showing an example of the configuration of a portion of a mobile station. [Figure 7] Block diagram showing an example of the configuration of a base station [Figure 8] A block diagram showing a configuration example of a mobile station [Figure 9] Flowchart showing an example of the operation of a base station and a mobile station [Figure 10] FIG. 1 shows an example of signal arrangement according to operation example 1-1. [Figure 11] FIG. 1 shows an example of signal arrangement according to operation example 1-2. [Figure 12]FIG. 1 shows an example of signal arrangement according to operation example 1-3. [Figure 13] FIG. 1 shows an example of signal arrangement according to operation example 1-4. [Figure 14] FIG. 1 shows an example of signal arrangement according to operation example 1-4. [Figure 15] A diagram showing an example of operation when orthogonal DMRS based MU-MIMO is not in operation. [Figure 16] FIG. 2 shows an example of signal arrangement according to operation example 2-1. [Figure 17] FIG. 2 shows an example of signal arrangement according to operation example 2-2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

[0013] [Dynamic Spectrum Sharing (DSS)] In DSS, NR systems and LTE systems can coexist and communicate simultaneously in the same frequency band.

[0014] For example, in the operation of DSS in Release 15 (hereinafter referred to as Rel-15), a channel for LTE may be arranged in a downlink subframe of LTE in a frequency band (or carrier) of LTE. For example, as shown in Fig. 1, in a downlink subframe of LTE, a control signal for LTE and a reference signal (e.g., a Cell-specific Reference Signal (CRS)) may be arranged in one or more symbols (e.g., an Orthogonal Frequency Division Multiplexing (OFDM) symbol) from the beginning, and a downlink data channel for LTE (e.g., an LTE Physical Downlink Shared Channel (PDSCH)) and a CRS may be arranged in the remaining OFDM symbols.

[0015] In DSS, for example, in a period of an OFDM symbol in which an LTE PDSCH is arranged, as shown in Fig. 1, an LTE PDSCH may be arranged in some frequency bands, and an NR downlink control channel (NR PDCCH: Physical Downlink Control Channel) or a downlink data channel (NR PDSCH) may be arranged in other frequency bands. In other words, the LTE PDSCH and each NR channel may be frequency-divided. However, as shown in Fig. 1, the CRS (or may be called LTE CRS) may be transmitted not only in the frequency band in which the LTE PDSCH is arranged, but also in the frequency band in which each NR channel is arranged.

[0016] For example, with regard to DSS, the introduction of a mapping method of PDSCH with a length of 9 and 10 OFDM symbols (for example, referred to as NR PDSCH mapping Type B) has been proposed (for example, see Non-Patent Document 3). For example, in this PDSCH mapping method, the position of an NR reference signal (for example, a demodulation reference signal (DMRS)) can be defined or set at a symbol position that does not collide with a symbol including an LTE CRS. The introduction of this NR PDSCH mapping Type B improves the operational efficiency of DSS.

[0017] However, such mapping of the PDSCH is not specified in Rel-15 (see, for example, Non-Patent Document 4), and the arrangement of the DMRS in this PDSCH has not been fully considered.

[0018] Therefore, in one embodiment of the present disclosure, a method for arranging DMRSs in a PDSCH will be described.

[0019] [DMRS mapping] As an example of a method of arranging DMRS in an uplink data channel (e.g., PUSCH: Physical Uplink Shared Channel), a method of arranging DMRS in NR PUSCH mapping Type B having a length of 9 and 10 OFDM symbols is specified in Non-Patent Document 4 (e.g., Section 6.4.1.1.3).

[0020] For example, a similar arrangement method to the arrangement method of DMRS in NR PUSCH mapping Type B can be applied to DMRS in NR PDSCH mapping Type B having a length of 9 and 10 OFDM symbols in a downlink data channel (e.g., PDSCH). For example, the arrangement method of DMRS in NR PDSCH mapping Type B having a length of 9 and 10 OFDM symbols can be as shown in Fig. 2. For example, "dmrs-AdditionalPosition" shown in Fig. 2 is a higher layer parameter (e.g., also referred to as a radio resource control (RRC) parameter) indicating the position of the DMRS (in other words, Additional DMRS). For example, dmrs-AdditionalPosition is notified (in other words, configured) from a base station (e.g., also referred to as a gNB) to a mobile station (e.g., also referred to as a terminal or UE: User Equipment).

[0021] In the following, the DMRS arrangement method shown in FIG. 2 is referred to as “Assumption 1.” For example, in Assumption 1 shown in FIG. 2, d In the case of "dmrs-AdditionalPosition"=9 or 10, the DMRS can be placed in the first symbol (or starting symbol) "l0" where the PDSCH is scheduled in the slot, and in the symbol indicated by "dmrs-AdditionalPosition" (for example, the position based on l0 (=0)).

[0022] [NR DMRS shift] As described above, in DSS, for example, the NR PDSCH may be transmitted in the frequency band in which the LTE CRS is transmitted. At this time, the DMRS in the NR PDSCH and the LTE CRS may be designed not to collide in time resources and frequency resources (for example, see Non-Patent Document 3).

[0023] For example, if there is a possibility of collision between the LTE CRS and a DMRS in an NR PDSCH configured based on "Assumption 1," the base station may transmit the DMRS at a position different from the position (in other words, the resource position) of the DMRS configured based on "Assumption 1." Here, for example, the process of changing the position of the DMRS to a position different from the position configured based on "Assumption 1" may be referred to as a "DMRS shift."

[0024] [CRS mapping] The symbol (in other words, the position in the time domain) in which the CRS is arranged in the LTE subframe varies depending on, for example, the number of ports of the CRS or the type of the subframe. The types of subframe include, for example, a multimedia broadcast service single frequency network (MBSFN subframe) and a non-MBSFN subframe. FIG. 3 shows an example of a method of arranging the CRS. For example, in an MBSFN subframe in which the number of CRS ports is 1 or 2, the CRS is transmitted in four symbols, 0th, 4th, 7th, and 11th. Also, for example, in an MBSFN subframe in which the number of CRS ports is 4, the CRS is transmitted in six symbols, 0th, 1st, 4th, 7th, 8th, and 11th. Also, for example, in a non-MBSFN subframe, the CRS is transmitted in one symbol, 0th, or two symbols, 0th and 1st.

[0025] It should be noted that the first symbol in a subframe or slot is referred to as the "0th symbol" here.

[0026] In addition, the location and number of ports in the frequency domain of the CRS, and the timing of the MBSFN subframe may be configured in the mobile station by, for example, higher layer parameters (for example, the RRC parameter "RateMatchPatternLTE-CRS").

[0027] [multi-user muitiple input multiple output(MU-MIMO)] In MU-MIMO for multiple mobile stations, there is an operation in which the NR DMRS ports between the mobile stations are orthogonal to each other (for example, called orthogonal DMRS based MU-MIMO). In the case of orthogonal DMRS based MU-MIMO, for example, as shown in FIG. 4, it is assumed that the NR DMRS ports between mobile station A and mobile station B are orthogonal to each other.

[0028] Here, for example, when DSS operation is performed for mobile station A and DSS operation is not performed for mobile station B, a case may occur (not shown) where DMRS shift is performed for mobile station A and DMRS shift is not performed for mobile station B. In this case, the positions of the DMRSs of mobile station A and mobile station B are different, and therefore the orthogonality between the DMRS ports may be lost.

[0029] For example, in Rel-15, DCI related to antenna port mapping notifies a mobile station that "all the remaining orthogonal antenna ports are not associated with transmission of PDSCH to another UE," thereby implicitly notifying the mobile station that orthogonal DMRS based MU-MIMO will be operated (for example, see Non-Patent Document 6).

[0030] (Embodiment 1) [Communication system overview] The communication system according to this embodiment includes a base station (corresponding to a transmitting device) 100 and a mobile station (corresponding to a receiving device) 200.

[0031] In this embodiment, for example, a method is described in which base station 100 and mobile station 200 determine whether or not to change (in other words, shift) the symbol in which DMRS is placed in a slot (e.g., called an NR slot) for transmitting an NR signal (e.g., PDSCH) in the downlink to a symbol different from a set symbol (e.g., a symbol based on assumption 1).

[0032] This determination allows base station 100 and mobile station 200 to suppress collision between DMRS and CRS, even when, for example, orthogonal DMRS based MU-MIMO is operated for mobile station 200. Furthermore, base station 100 and mobile station 200 can suppress loss of orthogonality of DMRS ports between mobile stations 200.

[0033] Fig. 5 is a block diagram showing a configuration example of a part of a base station 100 according to the present embodiment. In the base station 100 shown in Fig. 5, a control unit 101 (e.g., corresponding to a control circuit) determines the arrangement of a second reference signal (e.g., DMRS) in a second system (e.g., NR system) based on information capable of identifying the arrangement of a first reference signal (e.g., CRS) in a first system (e.g., LTE system). A transmission unit 104 (e.g., corresponding to a transmission circuit) transmits the second reference signal in the determined arrangement.

[0034] Fig. 6 is a block diagram showing an example of a configuration of a part of a mobile station 200 according to this embodiment. In the mobile station 200 shown in Fig. 6, a control unit 206 (e.g., corresponding to a control circuit) determines the allocation of a second reference signal (e.g., DMRS) in a second system (e.g., NR system) based on information capable of identifying the allocation of a first reference signal (e.g., CRS) in a first system (e.g., LTE system). A receiving unit 202 (e.g., corresponding to a receiving circuit) receives the second reference signal based on the determined allocation.

[0035] [Base station configuration] Fig. 7 is a block diagram showing an example of the configuration of base station 100 according to this embodiment. In Fig. 7, base station 100 has a control unit 101, an encoding and modulation unit 102, a signal mapping unit 103, a transmitting unit 104, and an antenna 105.

[0036] The control unit 101 generates, for example, a higher layer signal (for example, an RRC parameter) including a parameter to be set in the mobile station 200, and outputs the signal to the coding and modulation unit 102. The higher layer signal may include, for example, information related to the LTE CRS (for example, RateMatchPatternLTE-CRS) or information related to a band to be set in the mobile station 200 (for example, active BWP: Bandwidth part).

[0037] Furthermore, the control unit 101 determines information related to data (for example, PDSCH). For example, the control unit 101 determines an active BWP in which the PDSCH is transmitted, an allocation region of the PDSCH (for example, referred to as a PDSCH region), or whether orthogonal DMRS port based MU-MIMO is to be operated. Then, the control unit 101 outputs downlink control information (for example, DCI: Downlink Control Information) including information for explicitly or implicitly notifying the determined information to the signal mapping unit 103. Furthermore, the control unit 101 outputs (in other words, instructs) the determined PDSCH region to the signal mapping unit 103.

[0038] Furthermore, control section 101 determines whether or not to change (in other words, shift) the position of the DMRS in the PDSCH (e.g., the position of the symbol) from a reference position (e.g., a position associated with the PDSCH region, e.g., the position of Assumption 1 shown in FIG. 2). Control section 101 outputs information related to the determined position of the DMRS to signal mapping section 103.

[0039] The coding and modulation section 102 performs error correction coding and modulation on data (for example, PDSCH) and the upper layer signal inputted from the control section 101 , and outputs the modulated signal to the signal mapping section 103 .

[0040] Signal mapping section 103 maps (in other words, assigns or maps) DCI inputted from control section 101 to resources of the PDCCH region, for example. Furthermore, signal mapping section 103 maps DMRS and signals inputted from coding and modulation section 102 to resources of the PDSCH region. Signal mapping section 103 outputs the signals mapped to the resources to transmitting section 104.

[0041] The transmitting section 104 performs radio transmission processing such as frequency conversion using a carrier wave on the signal input from the signal mapping section 103 , and outputs the signal after the radio transmission processing to the antenna 105 .

[0042] The antenna 105 radiates the signal input from the transmitting unit 104 (in other words, a downlink signal) toward the mobile station 200.

[0043] [Mobile station configuration] Fig. 8 is a block diagram showing an example of the configuration of mobile station 200 according to this embodiment. In Fig. 8, mobile station 200 has antenna 201, receiving section 202, signal separating section 203, channel estimating section 204, demodulating and decoding section 205, and control section 206.

[0044] The antenna 201 receives a downlink signal transmitted by the base station 100 (see, for example, FIG. 7), and outputs the received signal to the receiving unit 202.

[0045] Receiving section 202 performs radio reception processing such as frequency conversion on the signal input from antenna 201 , and outputs the signal after radio reception processing to signal separating section 203 .

[0046] Signal separating section 203 extracts (in other words, separates) DCI, for example, arranged in resources of the PDCCH region, from the signal input from receiving section 202, and outputs the DCI to control section 206. Furthermore, signal separating section 203 extracts (in other words, separates) a data signal and a DMRS arranged in resources of the PDSCH region, based on information indicating the resources of the PDSCH region and information indicating the position of the DMRS input from control section 206. Signal separating section 203 outputs the data signal to demodulation and decoding section 205, and outputs the DMRS to channel estimation section 204.

[0047] Channel estimating section 204 performs channel estimation (for example, calculation of a channel estimation value) based on the DMRS inputted from signal separating section 203. Channel estimating section 204 outputs information indicating the channel estimation value to demodulating and decoding section 205.

[0048] The demodulation and decoding unit 205 demodulates and decodes the data signal input from the signal separation unit 203, based on the channel estimation value input from the channel estimation unit 204. The demodulation and decoding unit 205 outputs the upper layer signal obtained by decoding to the control unit 206.

[0049] Based on the higher layer signal input from demodulation and decoding section 205 and the DCI input from signal separation section 203, control section 206 identifies, for example, the PDSCH region and the position of the DMRS associated with the PDSCH region.

[0050] Furthermore, control section 206 determines whether the position of the DMRS in the PDSCH (eg, the position of the symbol) has been changed (in other words, shifted) from the reference position (eg, the position of assumption 1 shown in FIG. 2).

[0051] Control section 206 outputs information relating to the PDSCH region and information relating to the position of the DMRS to signal separation section 203.

[0052] [Example of operation of base station 100 and mobile station 200] Next, an operation example of the base station 100 (see FIG. 7) and the mobile station 200 (see FIG. 8) will be described.

[0053] FIG. 9 is a flowchart showing an example of the processing of the base station 100 and the mobile station 200.

[0054] The base station 100 notifies (in other words, configures) the upper layer signal to the mobile station 200 (ST101). The mobile station 200 receives the uplink layer signal notified from the base station 100.

[0055] The upper layer signal may include, for example, information regarding LTE CRS (e.g., RateMatchPatternLTE-CRS), or information regarding the allocated band for the mobile station 200 (e.g., active BWP). Further, for example, the information regarding the active BWP may include information regarding the subcarrier spacing (SCS) set for the mobile station 200. Note that these pieces of information may be notified to the mobile station 200 by at least one of the upper layer parameters and the downlink control information (e.g., DCI), or may be preset in the mobile station 200.

[0056] The base station 100 determines the content of the DCI to be notified to the mobile station 200 (ST102). The DCI may include, for example, the following information.

[0057] <PDSCH Allocation Information> The PDSCH allocation information may include, for example, information regarding the resources in the frequency domain to which the PDSCH (e.g., mapping type B) is allocated, and information such as the resources in the time domain where the PDSCH is arranged (e.g., start symbol and symbol length).

[0058] <Transmission Band Information of PDSCH> The transmission band information of the PDSCH may include, for example, information regarding the BWP in which the PDSCH is transmitted (including information regarding the subcarrier spacing).

[0059] <Information on orthogonal DMRS port based MU-MIMO> The information on orthogonal DMRS port based MU-MIMO may include, for example, information indicating whether orthogonal DMRS port based MU-MIMO is applied to the mobile station 200. The information on orthogonal DMRS port based MU-MIMO may be explicitly notified or implicitly notified from the base station 100 to the mobile station 200, for example.

[0060] Note that the information included in the DCI is not limited to the above-described information, and other information may also be used.

[0061] Based on the information set for the mobile station 200 (for example, the information included in the upper layer parameters and the DCI), the base station 100 determines whether to set (in other words, change or shift) the position of the DMRS in the PDSCH to a position different from the set position (for example, the position of "Assumption 1" shown in FIG. 2) (ST103). For example, the base station 100 may determine whether the condition for shifting the DMRS is "true" or "false".

[0062] When it is determined to shift the DMRS (ST103: YES), the base station 100 determines the position of the DMRS to a different n-th symbol from the m-th symbol set for the mobile station 200, for example (ST104). In other words, the position of the DMRS set for the mobile station 200 is shifted from the m-th symbol to the n-th symbol.

[0063] On the other hand, when it is determined not to shift the DMRS (ST103: NO), the base station 100 does not change (shift) the position of the DMRS.

[0064] Base station 100 transmits a downlink signal to mobile station 200 (ST105). The downlink signal may include, for example, at least one of a PDSCH including a DMRS and a PDCCH including a DCI. Note that the DMRS is placed in, for example, a position (for example, a symbol) determined by base station 100.

[0065] Mobile station 200 receives, for example, a downlink signal transmitted from base station 100, and checks the information (in other words, the contents) indicated in the DCI in the PDCCH included in the downlink signal (ST106). For example, mobile station 200 may determine that the position of the DMRS is set to the m-th symbol based on the allocation information of the PDSCH.

[0066] Mobile station 200 determines, for example, based on the received higher layer signal and information indicated in the DCI, whether or not the position of the DMRS in the PDSCH has been set (in other words, changed or shifted) to a position (for example, the nth symbol) different from the set position (for example, the mth symbol) (ST107). For example, mobile station 200 may determine whether the condition for shifting the DMRS is "true" or "false".

[0067] If it is determined that the DMRS is to be shifted (ST107: YES), mobile station 200 determines the position of the DMRS to be, for example, the nth symbol different from the mth symbol set in mobile station 200 (ST108). In other words, the position of the DMRS set in mobile station 200 is shifted from the mth symbol to the nth symbol.

[0068] On the other hand, if it is determined not to shift the position of the DMRS (ST107: NO), mobile station 200 does not change (shift) the position of the DMRS.

[0069] Mobile station 200 performs reception processing (eg, demodulation processing) of the PDSCH, for example, based on the DMRS allocated to the determined position (ST109).

[0070] Next, an example of the operation of DMRS allocation according to the present embodiment will be described.

[0071] <Example 1-1> In operation example 1-1, a method will be described in which, for example, base station 100 and mobile station 200 determine whether or not to change (in other words, shift) the position of a DMRS set to the 11th symbol (e.g., m=11) in an NR slot to the 12th symbol (n=12).

[0072] As an example, a case will be described in which the NR PDSCH for mobile station 200 is allocated to nine symbols from the fifth symbol to the thirteenth symbol in a slot, as shown in Fig. 10(a). In this case, for example, based on "Assumption 1" shown in Fig. 2, the position of the DMRS in the PDSCH is set to the eleventh symbol corresponding to l=6, as shown in Fig. 10(a).

[0073] 3, for example, a CRS can be placed in the 11th symbol in a slot, but a CRS cannot be placed in the 12th symbol. Therefore, for example, by setting (in other words, changing or shifting) the position of a DMRS to the 12th symbol, which is different from the 11th symbol, it is possible to suppress collision between a DMRS in an NR PDSCH and an LTE CRS.

[0074] For example, when the content indicated in the configuration information of mobile station 200 satisfies at least one of the following conditions, base station 100 and mobile station 200 determine the position of the DMRS to be the 12th symbol different from the 11th symbol configured in mobile station 200 as shown in FIG. 10(b) (for example, the processing of ST103 and ST107 shown in FIG. 9). In other words, in the processing of ST103 and ST107 shown in FIG. 9, base station 100 and mobile station 200 may determine that the condition for shifting the DMRS is "true" when the content indicated in the information configured in mobile station 200 (for example, information that can specify (or estimate) the placement of the LTE CRS) satisfies the following conditions:

[0075] Condition (1): "The mobile station 200 is not operating in an unlicensed band (e.g., also called NR-unlicensed (NR-U))." The NR frequency band (e.g., a licensed band or an unlicensed band) configured for the mobile station 200 may be notified to the mobile station 200 from the base station 100 by, for example, control information (e.g., an upper layer signal or DCI), or may be configured in the mobile station 200.

[0076] For example, it may be assumed that DSS is not used in an unlicensed band. Therefore, when mobile station 200 operates in an unlicensed band, the DMRS included in the NR signal for mobile station 200 does not collide with the LTE CRS, and therefore the position of the DMRS in the NR PDSCH (for example, the 11th symbol) does not need to be changed.

[0077] On the other hand, since DSS may be operated in a licensed band, for example, a CRS may be placed in the 11th symbol in a slot as shown in Fig. 3. Therefore, if the mobile station 200 is not operated in an unlicensed band, it may be determined that the LTE CRS and the DMRS may overlap.

[0078] Therefore, for example, when condition (1) is satisfied, the base station 100 and the mobile station 200 may determine the location of the DMRS to be the 12th symbol, which is different from the 11th symbol. In other words, when the mobile station 200 is operating in a licensed band, the base station 100 and the mobile station 200 may determine the location of the DMRS to be the 12th symbol.

[0079] Condition (2): “The RRC parameter RateMatchPatternLTE-CRS is set for the mobile station 200.” For example, when RateMatchPatternLTE-CRS is set in mobile station 200, since LTE CRS may be set in the LTE system, there is a possibility that the DMRS in the NR PDSCH and the LTE CRS may overlap. For example, as shown in Fig. 3, since a CRS may be placed in the 11th symbol in a slot, it may be determined that the DMRS in the NR PDSCH and the LTE CRS may overlap in the 11th symbol.

[0080] Therefore, when condition (2) is satisfied, base station 100 and mobile station 200 may determine the position of the DMRS to be the 12th symbol, which is different from the 11th symbol.

[0081] Condition (3): "The RRC parameter RateMatchPatternLTE-CRS is configured for the mobile station 200, and the timing of the MBSFN subframe configured by this RRC parameter does not match the transmission timing of the DMRS." For example, in an MBSFN subframe, the CRS may be placed in the 0th or 1st symbol, as shown in Figure 3. Therefore, when the timing of the MBSFN subframe coincides with the transmission timing of the DMRS, the DMRS in the PDSCH and the LTE CRS cannot collide, so the position of the DMRS in the NR PDSCH (e.g., the 11th symbol) does not need to be changed.

[0082] On the other hand, if the timing of the MBSFN subframe does not match the transmission timing of the DMRS, for example, if the timing of a non-MBSFN subframe matches the transmission timing of the DMRS, it may be determined that the DMRS in the PDSCH may collide with the LTE CRS, since the CRS may be placed in the 11th symbol, as shown in FIG. 3.

[0083] Therefore, when condition (3) is satisfied, base station 100 and mobile station 200 may determine the position of the DMRS to be the 12th symbol, which is different from the 11th symbol.

[0084] As described above, in an MBSFN subframe, a DMRS is not allocated to the 11th symbol, so condition (3) is a condition in which the DMRS and CRS are more likely to collide than condition (2).

[0085] Condition (4): "An active BWP with a subcarrier spacing (SCS) of 15 kHz is used in the mobile station 200." When the SCS set in the mobile station 200 in the NR system is 15 kHz, i.e., when the subcarrier spacing is the same as that in the LTE system, for example, as shown in FIG. 3, it may be determined that the DMRS in the NR PDSCH and the LTE CRS may collide in the 11th symbol.

[0086] Therefore, when condition (4) is satisfied, base station 100 and mobile station 200 may determine the position of the DMRS to be the 12th symbol, which is different from the 11th symbol.

[0087] Condition (5): "orthogonal DMRS port based MU-MIMO is being used for mobile station 200" For example, when orthogonal DMRS port based MU-MIMO is notified to mobile station 200 by DCI, if the position of the DMRS is changed in at least one mobile station 200 among multiple mobile stations 200 multiplexed in MU-MIMO, the orthogonality of the DMRS among the multiple mobile stations 200 may be lost.

[0088] Therefore, when condition (5) is satisfied, base station 100 and mobile station 200 may determine the position of the DMRS to be the 12th symbol, which is different from the 11th symbol.

[0089] In other words, when condition (5) is satisfied, the position of the DMRS for multiple mobile stations 200 operating in orthogonal DMRS port based MU-MIMO is set to the 12th symbol. By setting the DMRS in this manner, even if the position of the DMRS for mobile station 200 operating in DSS is changed, the position of the DMRS for other mobile stations 200 multiplexed in MU-MIMO is also changed accordingly, so that it is possible to suppress the orthogonality of the DMRSs between multiple mobile stations 200 from being lost.

[0090] For example, in the example shown in FIG. 4, when mobile station B is notified that orthogonal DMRS port based MU-MIMO is in operation, mobile station B may determine the position of the DMRS to be the 12th symbol, taking into consideration that even if DSS is not in operation for mobile station B, DSS may be in operation for another mobile station A that is multiplexed in MU-MIMO.

[0091] Condition (5) may be defined as, for example, "implying that the DCI received by mobile station 200 is orthogonal DMRS port based MU-MIMO."

[0092] Condition (6): "DCI received by mobile station 200 indicates allocation by PDSCH mapping type B" In the case of PDSCH mapping type B, for example, as shown in Fig. 2, d In the case of l=9, a DMRS in a PDSCH may be arranged in the 11th symbol corresponding to l=6. Also, for example, as shown in Fig. 3, a CRS may be arranged in the 11th symbol in a slot. Therefore, when PDSCH mapping type B is configured, a DMRS in an NR PDSCH and an LTE CRS may collide in the 11th symbol.

[0093] Therefore, when condition (6) is satisfied, base station 100 and mobile station 200 may determine the position of the DMRS to be the 12th symbol, which is different from the 11th symbol.

[0094] Condition (7): "DCI received by mobile station 200 indicates allocation by PDSCH mapping type B, and the allocation is "9 symbols from the 5th symbol to the 13th symbol." As explained in condition (6), in the case of allocation by PDSCH mapping type B, the length of the PDSCH is 9 symbols (for example, the l d In the case of l=6 (l=9), a DMRS in a PDSCH may be mapped to the 11th symbol corresponding to l=6. Also, for example, as shown in Fig. 3, a CRS may be mapped to the 11th symbol in a slot. Therefore, when PDSCH mapping type B is configured, a collision may occur between a DMRS in an NR PDSCH and an LTE CRS in the 11th symbol.

[0095] Therefore, when condition (7) is satisfied, base station 100 and mobile station 200 may determine the position of the DMRS to be the 12th symbol, which is different from the 11th symbol.

[0096] For example, as shown in FIG. 2, in the case of single symbol DMRS, the length of PDSCH is 10 symbols (for example, the l d = 10), no DMRS is placed in the 11th symbol (corresponding to l = 7). Therefore, condition (7) is a condition in which the DMRS and CRS are more likely to collide than condition (6).

[0097] Conditions (1) to (7) have been explained above.

[0098] Base station 100 and mobile station 200 may determine whether to position the DMRS at the 11th symbol or the 12th symbol, based on, for example, any one or more of conditions (1) to (7).

[0099] According to operation example 1-1, for example, when a DMRS in an NR PDSCH may collide with an LTE CRS, base station 100 and mobile station 200 determine (in other words, change or shift) the position of the DMRS in the NR PDSCH to the 12th symbol that does not collide with the CRS based on information set in mobile station 200. By determining the DMRS position in this way, it is possible to avoid collision between the DMRS in the NR PDSCH and the LTE CRS.

[0100] Furthermore, for example, base station 100 and mobile station 200 may determine that orthogonal DMRS based MU-MIMO can be implemented for mobile station 200 when at least one of the above-mentioned conditions (1) to (7) is satisfied.

[0101] For example, base station 100 performs DMRS shift for each of multiple mobile stations 200 in which orthogonal DMRS based MU-MIMO is operated. Also, each mobile station 200 in which orthogonal DMRS based MU-MIMO is operated determines that DMRS shift is to be performed for that mobile station 200 as well, assuming that DMRS shift may be performed in other mobile stations 200 that are MU-MIMO multiplexed in order to avoid collision between DMRS and CRS. This determination can reduce disruption of orthogonality between DMRS ports corresponding to multiple mobile stations 200, when orthogonal DMRS based MU-MIMO is operated for mobile station 200.

[0102] As described above, according to the operation example 1-1, for example, collision between the DMRS and the CRS can be avoided. Also, according to the operation example 1-1, for example, orthogonality between the DMRS ports can be maintained.

[0103] In the operation example 1-1, the case where m=11 and n=12 has been described, but the position of the DMRS after the change (in other words, after the shift) is not limited to the 12th symbol, and may be, for example, the 13th symbol or a symbol after the 10th symbol or a symbol before the 9th symbol. By changing to these symbols, for example, it is possible to flexibly arrange the DMRS at a time position or interval suitable for improving the accuracy of channel estimation in the mobile station 200.

[0104] <Example 1-2> In operation example 1-2, a method will be described in which, for example, base station 100 and mobile station 200 determine whether or not to change (in other words, shift) the position of a DMRS set to the 8th symbol (e.g., m=8) in an NR slot to the 9th symbol (e.g., n=9).

[0105] As an example, a case will be described in which the NR PDSCH for mobile station 200 is allocated to nine symbols from the fifth symbol to the thirteenth symbol in a slot, as shown in Fig. 11(a). In this case, for example, based on "Assumption 1" shown in Fig. 2, the position of the DMRS in the PDSCH is set to the eighth symbol corresponding to l=3, as shown in Fig. 11(a).

[0106] 3, for example, a CRS can be placed in the 8th symbol in a slot, but a CRS cannot be placed in the 9th symbol. Therefore, for example, by setting (in other words, changing or shifting) the position of the DMRS to the 9th symbol, which is different from the 8th symbol, it is possible to suppress collision between the DMRS in the NR PDSCH and the LTE CRS.

[0107] In operation example 1-2, for example, when the contents indicated in the configuration information of mobile station 200 satisfy at least one of conditions (1) to (7) described in operation example 1-1 and the following condition (8), base station 100 and mobile station 200 determine the position of the DMRS to be a 9th symbol, which is different from the 8th symbol set in mobile station 200, as shown in FIG. 11(b) (for example, the processing of ST103 and ST107 shown in FIG. 9).

[0108] Condition (8): Condition (8) is the case where “the RRC parameter RateMatchPatternLTE-CRS is configured for the mobile station 200, the number of CRS ports configured by this RRC parameter is 4, and the timing of the MBSFN subframe configured by this RRC parameter does not match the transmission timing of the DMRS.”

[0109] An example of a case where condition (8) is satisfied is a case where the timing of a non-MBSFN subframe coincides with the transmission timing of a DMRS. For example, as shown in FIG. 3, the number of CRS ports is 4, and in a non-MBSFN subframe, a CRS may be placed in the 8th symbol, so that the DMRS in the NR PDSCH and the LTE CRS may overlap in the 8th symbol.

[0110] Therefore, when condition (8) is satisfied, base station 100 and mobile station 200 may determine the position of the DMRS to be the ninth symbol, which is different from the eighth symbol.

[0111] Base station 100 and mobile station 200 may determine whether to position the DMRS at the eighth symbol or the ninth symbol, based on, for example, any one or more of conditions (1) to (8).

[0112] According to operation example 1-2, for example, when a DMRS in an NR PDSCH may collide with an LTE CRS, base station 100 and mobile station 200 determine (in other words, change or shift) the position of the DMRS in the NR PDSCH to the 9th symbol that does not collide with the CRS based on information set in mobile station 200. By determining the DMRS position in this way, it is possible to avoid collision between the DMRS in the NR PDSCH and the LTE CRS.

[0113] Furthermore, for example, base station 100 and mobile station 200 may determine that orthogonal DMRS based MU-MIMO can be implemented for mobile station 200 when at least one of the above conditions (1) to (8) is satisfied.

[0114] For example, base station 100 performs DMRS shift for each of multiple mobile stations 200 in which orthogonal DMRS based MU-MIMO is operated. Also, each mobile station 200 in which orthogonal DMRS based MU-MIMO is operated determines that DMRS shift is to be performed for that mobile station 200 as well, assuming that DMRS shift may be performed in other mobile stations 200 that are MU-MIMO multiplexed in order to avoid collision between DMRS and CRS. This determination can reduce disruption of orthogonality between DMRS ports corresponding to multiple mobile stations 200, when orthogonal DMRS based MU-MIMO is operated for mobile station 200.

[0115] As described above, according to the operation example 1-2, for example, collision between the DMRS and the CRS can be avoided. Also, according to the operation example 1-2, for example, orthogonality between the DMRS ports can be maintained.

[0116] In the operation example 1-2, the case where m=8 and n=9 has been described, but the position of the DMRS after the change (in other words, after the shift) is not limited to the 9th symbol, and may be, for example, the 10th symbol, the 11th symbol or a symbol after the 7th symbol or a symbol before the 6th symbol. By changing to these symbols, for example, it is possible to flexibly arrange the DMRS at a time position or interval suitable for improving the accuracy of channel estimation in the mobile station 200.

[0117] <Example 1-3> In operation example 1-3, a method will be described in which, for example, the base station 100 and the mobile station 200 determine whether or not to change (in other words, shift) the position of a DMRS (in other words, double symbol DMRS) set to the 10th and 11th symbols (for example, m=10 and 11) in an NR slot to the 12th and 13th symbols (for example, n=12 and 13).

[0118] As an example, a case will be described in which the NR PDSCH for mobile station 200 is allocated to nine symbols from the fifth symbol to the thirteenth symbol in a slot, as shown in Fig. 12(a). In this case, for example, based on "Assumption 1" shown in Fig. 2, the position of the DMRS in the PDSCH is set to the tenth and eleventh symbols corresponding to l=5, as shown in Fig. 12(a).

[0119] 3, for example, a CRS can be placed in the 8th symbol in a slot, but a CRS cannot be placed in the 9th symbol. Therefore, for example, by setting (in other words, changing or shifting) the position of the DMRS to the 9th symbol, which is different from the 8th symbol, it is possible to suppress collision between the DMRS in the NR PDSCH and the LTE CRS.

[0120] In operation example 1-3, for example, when the contents indicated in the configuration information of mobile station 200 satisfy at least one of conditions (1) to (7) described in operation example 1-1, base station 100 and mobile station 200 determine the position of the DMRS to be the 12th symbol and 13th symbol, which are different from the 10th symbol and 11th symbol set in mobile station 200, as shown in FIG. 12(b) (for example, the processing of ST103 and ST107 shown in FIG. 9).

[0121] Base station 100 and mobile station 200 may determine whether to position the DMRS at the 10th and 11th symbols, or at the 12th and 13th symbols, based on, for example, any one or more of conditions (1) to (7).

[0122] According to operation example 1-3, for example, when a DMRS in an NR PDSCH may collide with an LTE CRS, base station 100 and mobile station 200 determine (in other words, change or shift) the position of a double symbol DMRS in an NR PDSCH to the 12th and 13th symbols that do not collide with a CRS, based on information set in mobile station 200. By determining the DMRS position in this way, it is possible to avoid collision between a double symbol DMRS in an NR PDSCH and an LTE CRS.

[0123] Also, similarly to operation example 1-1, for example, base station 100 and mobile station 200 may determine that orthogonal DMRS based MU-MIMO can be implemented for mobile station 200 when at least one of the above-mentioned conditions (1) to (7) is satisfied.

[0124] For example, base station 100 performs DMRS shift for each of multiple mobile stations 200 in which orthogonal DMRS based MU-MIMO is operated. Also, each mobile station 200 in which orthogonal DMRS based MU-MIMO is operated determines that DMRS shift is to be performed for that mobile station 200 as well, assuming that DMRS shift may be performed in other mobile stations 200 that are MU-MIMO multiplexed in order to avoid collision between DMRS and CRS. This determination can reduce disruption of orthogonality between DMRS ports corresponding to multiple mobile stations 200, when orthogonal DMRS based MU-MIMO is operated for mobile station 200.

[0125] As described above, according to the operation example 1-3, for example, collision between the double symbol DMRS and the CRS can be avoided. Also, according to the operation example 1-3, for example, orthogonality between DMRS ports can be maintained.

[0126] In the operation example 1-3, the cases of m=10 and 11, and n=12 and 13 have been described, but the position of the DMRS after the change (in other words, after the shift) is not limited to the 12th and 13th symbols, and may be, for example, the 9th and 10th symbols, or the two symbols before the 9th symbol. By changing to these symbols, for example, it is possible to flexibly arrange the DMRS at a time position or interval suitable for improving the accuracy of channel estimation in the mobile station 200.

[0127] <Example 1-4> In operation example 1-4, a method is described in which, for example, base station 100 and mobile station 200 determine whether or not to change (in other words, shift) the position of a DMRS set to the 8th symbol (e.g., m=8) in an NR slot to the 10th symbol (e.g., n=10).

[0128] In operation example 1-4, for example, an active BWP having a subcarrier spacing of 30 kHz may be set for mobile station 200 (for example, the process of ST101 shown in FIG. 9).

[0129] Furthermore, base station 100 may allocate NR PDSCH to mobile station 200, for example, to nine symbols from the fifth symbol to the thirteenth symbol in a slot as shown in FIG. 11(a), or to ten symbols from the fourth symbol to the thirteenth symbol in a slot as shown in FIG. 13 (for example, the processing of ST102 shown in FIG. 9).

[0130] Also, for example, base station 100 may allocate a PDSCH to an active BWP having a subcarrier spacing of 30 kHz for mobile station 200 (for example, the process of ST102 shown in FIG. 9).

[0131] Furthermore, base station 100 may configure mobile station 200 to operate in orthogonal DMRS port based MU-MIMO (for example, the processing in ST 102 shown in FIG. 9).

[0132] For example, based on "Assumption 1" shown in FIG. 2, as shown in FIG. 11(a) and FIG. 13, d l=3 or l=9 d The position of the DMRS in the PDSCH is set to the 8th symbol corresponding to l=4 in =10.

[0133] When the SCS for NR is 30 kHz, the time corresponding to one symbol is half that of the SCS for LTE of 15 kHz. In other words, one symbol with SCS = 15 kHz is equivalent to two symbols with SCS = 30 kHz.

[0134] For example, in FIG. 3, the 4th symbol (or 11th symbol) in which the CRS is arranged in LTE with SCS=15kHz corresponds to two symbols, the 8th symbol and the 9th symbol, in NR with SCS=30kHz. Therefore, for example, in the 8th and 9th symbols in an NR slot with SCS=30kHz, the CRS can be arranged at a position equivalent to the 4th symbol (or the 11th symbol) in SCS=15kHz. In contrast, the CRS cannot be arranged in the 10th symbol (e.g., the 5th symbol or the 12th symbol in SCS=15kHz) in an NR slot with SCS=30kHz. Therefore, for example, the position of the DMRS in an NR slot with SCS=30kHz is set (in other words, changed or shifted) to the 10th symbol, which is different from the 8th symbol, thereby suppressing collision between the DMRS in the NR PDSCH and the LTE CRS.

[0135] In operation example 1-4, for example, when the contents indicated in the configuration information of mobile station 200 satisfy at least one of conditions (1) to (3), (5), and (6) described in operation example 1-1 and the following conditions (4)' and (7)', base station 100 and mobile station 200 determine the position of the DMRS to be the 10th symbol, which is different from the 8th symbol, as shown in Figures 14(a) and 14(b) (for example, the processing of ST103 and ST107 shown in Figure 9).

[0136] Condition (4)': "The mobile station 200 uses an active BWP with a subcarrier spacing (SCS) of 30 kHz." As described above, when the SCS for NR is 30 kHz, a collision may occur between the DMRS in the NR PDSCH and the LTE CRS in the 8th symbol in an NR slot.

[0137] Therefore, when condition (4)' is satisfied, the base station 100 and the mobile station 200 may determine the position of the DMRS to be the tenth symbol (for example, the symbol one symbol behind when SCS=15 kHz) different from the eighth symbol.

[0138] Condition (7)': "DCI received by mobile station 200 indicates allocation according to PDSCH mapping type B, and the allocation is "9 symbols from the 5th symbol to the 13th symbol" or "10 symbols from the 4th symbol to the 13th symbol." As described above, in the case of allocation by PDSCH mapping type B, the length of the PDSCH is 9 symbols (for example, the l d = 9) and the length of the PDSCH is 10 symbols (for example, the length d A DMRS in the PDSCH may be mapped to the 8th symbol corresponding to l=4 in the case of SCS=15 kHz (SCS=10), respectively. Also, as described above, a CRS may be mapped to the 4th symbol or the 11th symbol in a slot with SCS=15 kHz, which corresponds to the 8th symbol in SCS=30 kHz. Therefore, when PDSCH mapping type B is configured and the length of the PDSCH is 9 symbols and 10 symbols, a collision may occur between the DMRS in the NR PDSCH and the LTE CRS in the 8th symbol in an NR slot.

[0139] Therefore, when condition (7)' is satisfied, the base station 100 and the mobile station 200 may determine the position of the DMRS to be the tenth symbol (for example, the symbol one symbol behind when SCS=15 kHz) different from the eighth symbol.

[0140] The base station 100 and the mobile station 200 may determine whether to position the DMRS at the 8th symbol or the 10th symbol based on, for example, any one or more of conditions (1) to (3), (4)', (5), (6) and (7)'.

[0141] According to operation example 1-4, for example, when a DMRS in an NR PDSCH may collide with an LTE CRS, base station 100 and mobile station 200 determine (in other words, change or shift) the position of the DMRS in the NR PDSCH to the 10th symbol that does not collide with the CRS based on information set in mobile station 200. By determining the DMRS position in this way, it is possible to avoid collision between the DMRS in the NR PDSCH and the LTE CRS even if the SCS of NR is different from the SCS of LTE.

[0142] Furthermore, for example, when at least one of the above-mentioned conditions (1) to (3), (4)', (5), (6) and (7)' is satisfied, the base station 100 and the mobile station 200 may determine that orthogonal DMRS based MU-MIMO can be implemented for the mobile station 200.

[0143] For example, base station 100 performs DMRS shift for each of multiple mobile stations 200 in which orthogonal DMRS based MU-MIMO is operated. Also, each mobile station 200 in which orthogonal DMRS based MU-MIMO is operated determines that DMRS shift is to be performed for that mobile station 200 as well, assuming that DMRS shift may be performed in other mobile stations 200 that are MU-MIMO multiplexed in order to avoid collision between DMRS and CRS. This determination can reduce disruption of orthogonality between DMRS ports corresponding to multiple mobile stations 200, when orthogonal DMRS based MU-MIMO is operated for mobile station 200.

[0144] As described above, according to the operation example 1-4, for example, collision between the DMRS and the CRS can be avoided. Also, according to the operation example 1-4, for example, orthogonality between the DMRS ports can be maintained.

[0145] In the operation example 1-4, the case where m=8 and n=10 has been described, but the position of the DMRS after the change (in other words, after the shift) is not limited to the 10th symbol, and may be, for example, the 11th symbol, the 12th symbol or a symbol after the 7th symbol or the 6th symbol or a symbol before the 6th symbol. By changing to these symbols, for example, it is possible to flexibly arrange the DMRS at a time position or interval suitable for improving the accuracy of channel estimation in the mobile station 200.

[0146] As described above, in operation examples 1-1 to 1-4, a case has been described in which the position of a DMRS is determined based on the position of a DMRS and the position of a CRS that may be configured for mobile station 200 in Rel. 16. In other words, in operation examples 1-1 to 1-4, for example, base station 100 and mobile station 200 can identify symbols where a DMRS and a CRS may collide or symbols where a DMRS and a CRS may not collide, based on configuration information of mobile station 200.

[0147] For example, the conditions described in operation examples 1-1 to 1-4 do not depend on whether or not there is overlap (in other words, collision) between the symbol in which the CRS is allocated and the symbol set in the DMRS for the mobile station 200. Therefore, in operation examples 1-1 to 1-4, when the above-mentioned conditions are satisfied, the base station 100 and the mobile station 200 can maintain, for example, orthogonality between the DMRS ports corresponding to the multiple mobile stations 200 multiplexed in MU-MIMO by changing the allocation of the DMRS even if the CRS and the DMRS do not actually collide.

[0148] <Example 1-5> In operation example 1-5, an operation example in which the base station 100 and the mobile station 200 cannot determine whether or not there is a collision between the DMRS and the CRS based on the configuration information of the mobile station 200 will be described.

[0149] For example, in operation example 1-5, a method will be described in which the base station 100 and the mobile station 200 determine whether or not to change (in other words, shift) the position of a DMRS set to an arbitrary symbol in an NR slot to a different symbol.

[0150] In operation example 1-5, for example, an active BWP having a subcarrier spacing of 15 kHz, 30 kHz, or 60 kHz may be set for mobile station 200 (for example, the process of ST101 shown in FIG. 9).

[0151] Furthermore, base station 100 may allocate, to mobile station 200, for example, an NR PDSCH to a frequency band in which an LTE CRS can be transmitted and to any time resource within a slot (for example, the processing of ST102 shown in FIG. 9).

[0152] Also, for example, base station 100 may allocate a PDSCH to an active BWP having a subcarrier spacing of any of 15 kHz, 30 kHz, or 60 kHz for mobile station 200 (for example, the process of ST102 shown in FIG. 9).

[0153] Furthermore, base station 100 may configure mobile station 200 to operate in orthogonal DMRS port based MU-MIMO (for example, the processing in ST 102 shown in FIG. 9).

[0154] For example, the position of the DMRS in the PDSCH set based on "Assumption 1" shown in FIG. 2 is assumed to be the "xth symbol."

[0155] Base station 100 determines, for example, whether to change (in other words, shift) the position of the DMRS to a symbol (hereinafter referred to as the "y-th symbol") different from the x-th symbol set in mobile station 200 (for example, the process of ST103 shown in FIG. 9). For example, when the symbol in which the CRS is placed overlaps with the x-th symbol set in mobile station 200, base station 100 may determine the position of the DMRS to be the y-th symbol different from the x-th symbol.

[0156] For example, base station 100 may determine whether or not the symbol in which the CRS is allocated overlaps with the x-th symbol in which the DMRS is allocated, based on information on LTE CRS (e.g., information on the allocation of CRS) and information on resources configured in mobile station 200 (e.g., information on allocated resources in the frequency domain and time domain for PDSCH). In other words, base station 100 determines whether or not the CRS and the DMRS may collide in the x-th symbol. For example, when base station 100 determines that the CRS and the DMRS may collide, base station 100 may determine that the condition for shifting the DMRS is "true".

[0157] If the condition for shifting the DMRS is true (ST103: YES), base station 100 determines (in other words, changes or shifts) the position of the DMRS to the y-th symbol different from the x-th symbol (ST104). For example, base station 100 may allocate (in other words, shift) the DMRS to the y-th symbol having a smaller symbol number among symbols after the x-th symbol that do not collide with the CRS.

[0158] If there is no symbol that does not collide with the CRS among the symbols after the x-th symbol, base station 100 may arrange the DMRS in the x-th symbol (in other words, do not shift).

[0159] Furthermore, mobile station 200 determines whether to change the position of the DMRS to a different position (y-th symbol) from the position (x-th symbol) set based on the control signal notified from base station 100 (for example, the process of ST107 shown in FIG. 9). For example, when the symbol in which the CRS is placed overlaps with the x-th symbol set in mobile station 200, mobile station 200 may determine the position of the DMRS to be the y-th symbol, which is different from the x-th symbol.

[0160] For example, similar to base station 100, mobile station 200 determines whether or not the symbol in which CRS is allocated and the x-th symbol in which DMRS is allocated may overlap (in other words, collide) based on information related to LTE CRS and PDSCH allocation information set in mobile station 200. For example, when mobile station 200 determines that CRS and DMRS may collide, it may determine that the condition for shifting DMRS is "true".

[0161] If the condition for shifting the DMRS is true (ST107: YES), mobile station 200 determines that the position of the DMRS has been determined (in other words, changed or shifted) to the y-th symbol, which is different from the x-th symbol (ST108). For example, mobile station 200 may determine that the DMRS has been placed (in other words, shifted) to the y-th symbol having a smaller symbol number among symbols subsequent to the x-th symbol that do not collide with the CRS.

[0162] If there is no symbol that does not collide with a CRS among the symbols after the x-th symbol, mobile station 200 may determine that a DMRS is allocated to the x-th symbol (in other words, may determine that there is no shift).

[0163] According to operation example 1-5, for example, when the DMRS in the NR PDSCH may collide with the LTE CRS, the base station 100 and the mobile station 200 determine (in other words, change or shift) the position of the DMRS in the NR PDSCH to another symbol that does not collide with the CRS. By determining the DMRS position, it is possible to avoid the collision between the DMRS in the NR PDSCH and the LTE CRS.

[0164] The subcarrier interval set in the mobile station 200 is not limited to 15 kHz, 30 kHz, or 60 kHz, and may be other intervals.

[0165] In addition, in the operation example 1-5, the y-th symbol is not limited to the smallest numbered symbol among the symbols after the x-th symbol that do not collide with a CRS, but may be, for example, the second smallest numbered symbol among the symbols that do not collide with a CRS, or the symbol after the third smallest numbered symbol. Alternatively, the y-th symbol may be a symbol that does not collide with a CRS before the x-th symbol. By changing to these symbols, for example, it is possible to flexibly arrange the DMRS at a time position or interval suitable for improving the accuracy of channel estimation in the mobile station 200.

[0166] In addition to determining whether or not the DMRS and the CRS may collide, the base station 100 and the mobile station 200 may also determine whether or not to change the position of the DMRS configured in the mobile station 200, based on, for example, whether or not the contents indicated in the configuration information of the mobile station 200 satisfy at least one of the above-mentioned conditions (1), (3), (5), and (8).

[0167] Furthermore, for example, when at least one of the above conditions (1), (3), (5) and (8) is satisfied, the base station 100 and the mobile station 200 may determine that the orthogonal DMRS based MU-MIMO can be implemented for the mobile station 200. For example, the base station 100 performs a DMRS shift for each of the multiple mobile stations 200 in which the orthogonal DMRS based MU-MIMO is implemented. Also, each mobile station 200 in which the orthogonal DMRS based MU-MIMO is implemented determines that the DMRS shift is to be implemented for the mobile station 200 as well, assuming that the DMRS shift may be implemented in other mobile stations 200 that are MU-MIMO multiplexed in order to avoid collision between the DMRS and CRS. This determination can reduce the breakdown of orthogonality between the DMRS ports corresponding to the multiple mobile stations 200 when the orthogonal DMRS based MU-MIMO is implemented for the mobile station 200.

[0168] An example of the operation of DMRS allocation has been described above.

[0169] As described above, in this embodiment, base station 100 and mobile station 200 determine the allocation of DMRS in the NR PDSCH based on, for example, information configured in mobile station 200 (in other words, information capable of identifying the allocation of LTE CRS). By determining this DMRS allocation, for example, base station 100 operating DSS can appropriately allocate DMRS and avoid collision between DMRS and CRS. Furthermore, by determining this DMRS allocation, for example, orthogonality between DMRS ports can be maintained. Furthermore, even when DSS is operated, mobile station 200 can appropriately determine the allocation of DMRS and receive NR PDSCH.

[0170] (Variation 1 of the first embodiment) In the first embodiment, when the DMRS is mapped to multiple symbols in a slot, base station 100 and mobile station 200 may simultaneously change (in other words, shift) the multiple symbols in which the DMRS is mapped.

[0171] For example, when the positions of the DMRS in "Assumption 1" shown in FIG. 2 are the eighth and eleventh symbols, the base station 100 and the mobile station 200 may change the positions of the respective DMRSs to the ninth and twelfth symbols.

[0172] This change in DMRS placement makes it possible to avoid collisions between multiple DMRSs and CRSs.

[0173] (Variation 2 of the first embodiment) In the first embodiment, for example, the information about the LTE system (e.g., RRC parameter RateMatchPatternLTE-CRS) notified from base station 100 to mobile station 200 in the processing of ST101 shown in FIG. 9 may be information about a CRS in an LTE component carrier (CC) operating in any of the following bands: (1) System band of the NR component carrier in which the base station 100 and the mobile station 200 operate (2) Any BWP set in the mobile station 200 (3) The active BWP used for transmission to the mobile station 200 (4) Allocated Bandwidth of PDSCH Transmitted to Mobile Station 200

[0174] Furthermore, in the case where there are multiple LTE component carriers in the above-mentioned band, the base station 100 may notify the mobile station 200 of a parameter indicating information related to the CRS of one or more LTE component carriers.

[0175] For example, when multiple parameters are notified, base station 100 and mobile station 200 may determine whether or not to change the position of the DMRS based on one or more parameters (for example, the processes in ST103 and ST107 shown in FIG. 9).

[0176] Furthermore, the base station 100 and the mobile station 200 may determine whether or not to change the location of the DMRS based on some of the multiple parameters. For example, the base station 100 and the mobile station 200 may operate based on parameters including a larger number of CRS ports among the multiple parameters, or may operate based on parameters in which non-MBSFN subframes are set more frequently. By such operation, for example, the location of the DMRS is determined taking into consideration a situation in which the CRS can be allocated to more resources, thereby reducing the possibility of collision between the CRS and the DMRS.

[0177] Furthermore, base station 100 may notify mobile station 200 of parameters based on which it is determined whether or not to change the location of the DMRS.

[0178] (Variation 3 of the First Embodiment) In the first embodiment, the condition for determining whether or not to change the position of the DMRS may be, for example, information known between the base station 100 and the mobile station 200, or may be information notified from the base station 100 to the mobile station 200 by a control signal such as a higher layer signal or a DCI.

[0179] Alternatively, information indicating the result of the decision as to whether or not to change the location of the DMRS may be transmitted from base station 100 to mobile station 200 by a control signal such as a higher layer signal or DCI.

[0180] This notification enables mobile station 200 to accurately determine whether the position of the DMRS transmitted by base station 100 has changed.

[0181] (Variation 4 of the First Embodiment) In the first embodiment, the fact that mobile station 200 is operated in the orthogonal DMRS port based MU-MIMO may be implicitly notified by, for example, DCI related to antenna port mapping notifying that "all the remaining orthogonal antenna ports are not associated with transmission of PDSCH to another UE".

[0182] (Variation 5 of the First Embodiment) In the first embodiment, the position of the DMRS received by mobile station 200 not operating in orthogonal DMRS based MU-MIMO may be shifted as shown in Fig. 15. This can mitigate, for example, degradation of reception accuracy caused by collision of DMRS between cells.

[0183] (Variation 6 of the First Embodiment) In the first embodiment, the parameters included in the conditions of each of the above operation examples are not limited to RateMatchPatternLTE-CRS, but may be, for example, parameters related to at least CRS or MBSFN subframes, and may be higher layer parameters having names different from RateMatchPatternLTE-CRS or parameters included in control signals such as DCI.

[0184] (Embodiment 2) For example, when multiple DMRSs are placed in a slot, as described in embodiment 1, changing the position of a DMRS that may collide with a CRS may change the positional relationship (e.g., time interval) between the DMRS whose position has been changed and other DMRSs (in other words, DMRSs whose position has not been changed).

[0185] For example, the greater the time interval between DMRSs, the more likely it is that the accuracy of channel estimation between the DMRSs will deteriorate.

[0186] Also, for example, the smaller the time interval between DMRSs, the less effective it is to arrange the DMRSs in multiple symbols. In other words, the smaller the time interval between DMRSs, the more overhead caused by the DMRSs increases, and the less efficient resource usage may be.

[0187] In this embodiment, a DMRS allocation method that suppresses deterioration of channel estimation accuracy and a DMRS allocation method that improves resource utilization efficiency will be described.

[0188] The base station and mobile station according to this embodiment have the same basic configuration as base station 100 and mobile station 200 according to the first embodiment.

[0189] Next, an example of the operation of DMRS allocation according to the present embodiment will be described.

[0190] <Example of operation 2-1> In operation example 2-1, for example, when DMRSs are placed in multiple symbols within a slot, base station 100 and mobile station 200 change (in other words, shift) the positions of DMRSs that may collide with CRS, as well as DMRSs that may not collide with CRS.

[0191] As an example, a case will be described in which NR PDSCH is allocated to nine symbols from the fifth symbol to the thirteenth symbol within a BWP with a subcarrier spacing of 15 kHz for mobile station 200 as shown in FIG. 16(a).

[0192] In this case, for example, based on "Assumption 1" shown in FIG. 2, the positions of the DMRS in the PDSCH are set to the 5th, 8th, and 11th symbols (l=0, 3, 6).

[0193] Also, for example, the base station 100 and the mobile station 200 determine that the CRS may be placed in at least the seventh symbol, the eighth symbol, and the eleventh symbol in the slot, as shown in FIG.

[0194] In this case, the base station 100 and the mobile station 200 determine that, for example, the DMRS and the CRS may collide in the eighth and eleventh symbols.

[0195] Therefore, base station 100 may change (in other words, shift) the positions of DMRSs that may be placed in the eighth and eleventh symbols, and the position of DMRSs that may be placed in the fifth symbol. For example, base station 100 may change the DMRSs in the fifth, eighth, and eleventh symbols shown in Fig. 16(a) to the sixth, ninth, and twelfth symbols, respectively, as shown in Fig. 16(b).

[0196] Furthermore, like base station 100, mobile station 200 may determine that the DMRSs in the fifth, eighth, and eleventh symbols shown in FIG. 16(a) are allocated to the sixth, ninth, and twelfth symbols, respectively, as shown in FIG. 16(b).

[0197] In operation example 2-1, when base station 100 and mobile station 200 change the position of at least one DMRS among a plurality of DMRSs in a slot, they change the positions of the remaining DMRSs based on the DMRS position (in other words, the change of position). For example, as shown in Fig. 16(a) and Fig. 16(b), three DMRSs in a PDSCH are each shifted one symbol backward from the position set in mobile station 200 (for example, the position based on "Assumption 1"). In other words, as shown in Fig. 16(b), the allocation interval between DMRSs after the change (for example, three symbols) remains the same as the allocation interval between DMRSs before the change (for example, three symbols).

[0198] With this DMRS allocation, even if the positions of the DMRSs are changed, the allocation intervals between multiple DMRSs in the time domain do not change, so that degradation of channel estimation accuracy due to DMRSs can be suppressed.

[0199] <Example of operation 2-2> In operation example 2-2, for example, when DMRSs are placed in multiple symbols within a slot, the base station 100 and the mobile station 200 decide not to transmit (in other words, drop) one of two DMRSs whose time interval is less than or equal to a threshold in the determined DMRS placement (in other words, the changed position).

[0200] As an example, a case will be described in which NR PDSCH is assigned to nine symbols from the fifth symbol to the thirteenth symbol within a BWP with a subcarrier spacing of 30 kHz for mobile station 200 as shown in FIG. 17(a).

[0201] Also, here, the threshold value for the time interval between DMRSs for determining whether or not to drop a DMRS is set to 1 symbol. Note that the threshold value is not limited to 1 symbol, and may be 2 symbols or more.

[0202] In this case, for example, based on "Assumption 1" shown in FIG. 2, the positions of the DMRS in the PDSCH are set to the 5th, 8th, and 11th symbols (l=0, 3, 6).

[0203] Also, for example, the base station 100 and the mobile station 200 determine that the LTE CRS (for example, a 15 kHz SCS) may be placed at least in the eighth symbol in the slot. In this case, the base station 100 and the mobile station 200 determine that the DMRS and the CRS may collide in the eighth symbol, for example.

[0204] Therefore, base station 100 and mobile station 200 determine (in other words, change or shift) the position of the DMRS to, for example, the 10th symbol, which is different from the 8th symbol. In this case, the determined arrangement of the DMRS is the 5th, 10th, and 11th symbols.

[0205] Here, since the interval between the DMRSs that can be placed in the 10th symbol and the 11th symbol is less than or equal to a threshold (1 symbol), the base station 100 and the mobile station 200 may decide to drop the DMRS that can be placed in the 10th symbol, for example, as shown in FIG. 17(b).

[0206] Therefore, as shown in FIG. 17(b), base station 100 may transmit the DMRS in the fifth and eleventh symbols, and mobile station 200 may receive the DMRS in the fifth and eleventh symbols.

[0207] Also, for example, base station 100 may transmit another signal (for example, PDSCH) in the tenth symbol after dropping the DMRS, as shown in FIG. 17(b).

[0208] For example, as shown in FIG. 17(b), when a DMRS is arranged in the 11th symbol, the channel estimation accuracy is about the same as when the DMRS is arranged in the 10th and 11th symbols. In the operation example 2-2, for example, as shown in FIG. 17(b), the DMRS is dropped in the 10th symbol, so that it is possible to suppress deterioration of the channel estimation accuracy and suppress an increase in overhead due to the DMRS. In addition, since another signal is arranged in the 10th symbol from which the DMRS is dropped, it is possible to improve resource utilization efficiency.

[0209] In FIG. 17(b), we have described a case in which the DMRS in the 10th symbol is dropped among the DMRSs that can be placed in the 10th and 11th symbols whose spacing is equal to or less than a threshold value, but the DMRS to be dropped may also be the DMRS in the 11th symbol.

[0210] The embodiments of the present disclosure have been described above.

[0211] (Other embodiments) In each of the above-described embodiments, it is assumed that the base station is a transmitting device and the mobile station is a receiving device, and that the downlink communication is performed. However, an embodiment of the present disclosure is not limited to this, and may be applied to an uplink communication in which the mobile station is a transmitting device and the base station is a receiving device, or a communication between mobile stations, i.e., a sidelink communication.

[0212] Furthermore, in each of the above embodiments, the case where the number of constituent symbols of a slot is 14 symbols has been described, but the number of constituent symbols of a slot is not limited to 14 symbols and may be another number of symbols (for example, 12 symbols).

[0213] Moreover, in each of the above embodiments, a case has been described in which the position (e.g., symbol) of the DMRS is changed (in other words, shifted). However, the signal whose position is changed is not limited to the DMRS, but may be other signals. Furthermore, in each of the above embodiments, a case has been described in which collision between the DMRS and the CRS is avoided by determining the DMRS position. However, the signal whose collision with the DMRS is to be considered is not limited to the CRS, but may be other signals different from the CRS. For example, an embodiment of the present disclosure may be applied to a reference signal, channel, or other signal in NR or LTE, such as the following, instead of at least one of the DMRS and the CRS. Phase Tracking Reference Signal (PT-RS, PTRS) -Channel State Information Reference Signal (CSI-RS) Sounding Reference Signal (SRS) Tracking Reference Signal (TRS) Discovery Reference Signal (Discovery Signal, DRS) Primary Synchronization Signal (PSS) Secondary Synchronization Signal (SSS) Downlink control channel (Physical Downlink Control Channel (PDCCH)) Physical Downlink Shared Channel (PDSCH) Physical Uplink Control Channel (PUCCH) Physical Uplink Shared Channel (PUSCH) ·Physical Broadcast Channel (PBCH) Physical Control Format Indicator Channel (PCFICH) Physical HARQ Indicator Channel (PHICH) Physical Multicast Channel (PMCH)

[0214] In addition, in each of the above embodiments, the mapping method of the PDSCH is not limited to PDSCH mapping type B. The mapping method of the PDSCH may be, for example, PDSCH mapping type A or another mapping method. An embodiment of the present disclosure can be applied to a case where a DMRS and a CRS may collide, for example, regardless of the mapping method of the PDSCH.

[0215] In addition, in each of the above embodiments, when changing (in other words, shifting) the position of the DMRS, it may be changed to another frequency position. For example, a DMRS belonging to a certain DMRS CDM group may be changed to a frequency position corresponding to another DMRS CDM group. This makes it possible to avoid collision with the CRS more flexibly.

[0216] In addition, in each of the above embodiments, the "higher layer signal" may be called, for example, an "RRC signal" or a "MAC signal".

[0217] In addition, in each of the above embodiments, the "reference signal" may be called, for example, a "reference signal" or a "pilot signal." Furthermore, the DMRS may be written as "DM-RS."

[0218] Furthermore, in each of the above embodiments, the unit of time resource is not limited to slot and symbol, but may be other time resource unit such as frame, subframe, or subslot.

[0219] The present disclosure can be realized by software, hardware, or software linked to hardware. Each functional block used in the description of the above embodiment may be realized partially or entirely as an LSI, which is an integrated circuit, and each process described in the above embodiment may be controlled partially or entirely by one LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of one chip to include some or all of the functional blocks. The LSI may have input and output data. Depending on the degree of integration, the LSI may be called an IC, a system LSI, a super LSI, or an ultra LSI. The method of integration is not limited to LSI, and may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. In addition, a field programmable gate array (FPGA) that can be programmed after LSI manufacture, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used. The present disclosure may be realized as digital processing or analog processing. Furthermore, if a new integrated circuit technology that can replace LSI appears due to the progress of semiconductor technology or a derivative technology, it is possible to integrate the functional blocks using that technology. The application of biotechnology is also a possibility.

[0220] The present disclosure may be implemented in any type of apparatus, device, or system having a communication function (collectively referred to as a communication apparatus). The communication apparatus may include a radio transceiver and processing / control circuitry. The radio transceiver may include a receiver and a transmitter, or both as functions. The radio transceiver (transmitter and receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones, etc.), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks, etc.), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smart watches, tracking devices, etc.), game consoles, digital book readers, telehealth and telemedicine devices, communication-enabled vehicles or mobile conveyances (e.g., cars, airplanes, boats, etc.), and combinations of the above devices.

[0221] Communications Equipment includes, but is not limited to portable or mobile equipment, non-portable or fixed equipment, devices and systems of any kind, such as smart home devices (appliances, lighting equipment, smart meters or metering devices, control panels, etc.), vending machines and any other "Things" that may exist on an Internet of Things (IoT) network.

[0222] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0223] A communications apparatus also includes devices, such as controllers and sensors, connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0224] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0225] A receiving device according to one embodiment of the present disclosure includes a control circuit that determines an arrangement of a second reference signal based on information capable of identifying an arrangement of a first reference signal, and a receiving circuit that receives the second reference signal based on the determined arrangement.

[0226] In one embodiment of the present disclosure, when the content indicated in the information satisfies a certain condition, the control circuit determines the position of the second reference signal to be a symbol different from the symbol set in the receiving device.

[0227] In one embodiment of the present disclosure, the condition does not depend on whether or not a symbol in which the first reference signal is arranged overlaps with a symbol set in the second reference signal for the receiving device.

[0228] In one embodiment of the present disclosure, based on the information, when a first symbol in which the first reference signal is placed overlaps with a second symbol set as the second reference signal for the receiving device, the control circuit determines the position of the second reference signal to be a third symbol different from the second symbol.

[0229] In one embodiment of the present disclosure, the control circuit determines whether the first symbol and the second symbol overlap based on allocation information of data including the second reference signal and information regarding the arrangement of the first reference signal.

[0230] In one embodiment of the present disclosure, the control circuit determines the position of the second reference signal to be the third symbol when the content indicated in the information satisfies a certain condition.

[0231] In one embodiment of the present disclosure, the condition does not depend on whether the first symbol and the second symbol overlap.

[0232] In one embodiment of the present disclosure, when the control circuit changes the position of at least one reference signal among the plurality of second reference signals, the control circuit changes the positions of the remaining reference signals based on the position of the at least one reference signal.

[0233] In one embodiment of the present disclosure, the control circuit determines not to transmit one of the two second reference signals whose time interval is equal to or less than a threshold in the determined configuration.

[0234] A transmitting device according to one embodiment of the present disclosure includes a control circuit that determines an arrangement of a second reference signal based on information capable of identifying an arrangement of a first reference signal, and a transmitting circuit that transmits the second reference signal in the determined arrangement.

[0235] In a receiving method according to one embodiment of the present disclosure, a receiving device determines a placement of a second reference signal based on information capable of identifying a placement of a first reference signal, and receives the second reference signal based on the determined placement.

[0236] In a transmission method according to one embodiment of the present disclosure, a transmitting device determines a placement of a second reference signal based on information capable of identifying a placement of a first reference signal, and transmits the second reference signal in the determined placement.

[0237] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2019-149144, filed on August 15, 2019, are incorporated herein by reference in their entirety. [Industrial Applicability]

[0238] An embodiment of the present disclosure is useful in a mobile communication system. [Explanation of symbols]

[0239] 100 base stations 101,206 Control section 102 Encoding and modulation section 103 Signal arrangement section 104 Transmitter 105,201 Antennas 200 Mobile Station 202 Receiving unit 203 Signal separation section 204 Channel Estimation Unit 205 Demodulation and Decoding Section

Claims

1. A control circuit that determines an arrangement of a second reference signal in a second system based on an arrangement of a first reference signal in a first system; a transmission circuit that transmits the second reference signal based on the determined arrangement; Equipped with When changing the position of at least one reference signal among the plurality of second reference signals, the control circuit changes positions of the remaining reference signals. Transmitting device.

2. When a certain condition is satisfied, the control circuit determines a position of the second reference signal to be a symbol different from a symbol set in the transmitting device. The transmitting device according to claim 1 .

3. The condition does not depend on whether a symbol in which the first reference signal is arranged and a symbol in which the second reference signal is set overlap. The transmitting device according to claim 2.

4. The control circuit determines a position of the second reference signal to be a third symbol different from the second symbol when a first symbol in which the first reference signal is placed and a second symbol set in the second reference signal overlap or when a certain condition is satisfied. The transmitting device according to claim 1 .

5. the control circuit determines whether or not the first symbol and the second symbol overlap based on an allocation method of the data including the second reference signal and an arrangement of the first reference signal. The transmitting device according to claim 4.

6. the condition does not depend on whether the first symbol and the second symbol overlap. The transmitting device according to claim 4.

7. The control circuit determines not to transmit one of the two second reference signals whose time interval is equal to or less than a threshold in the determined arrangement. The transmitting device according to claim 1 .

8. The control circuit determines a position of the second reference signal to be the third symbol when a subcarrier interval set in the transmitting device is a specific value. The transmitting device according to claim 4.

9. The control circuit determines the position of the second reference signal to be the third symbol when a subcarrier interval set in the transmitting device is 15 kHz. The transmitting device according to claim 4.

10. The control circuit determines a position of the second reference signal to be the third symbol when a PDSCH resource is notified by PDSCH mapping type B and the PDSCH resource has a specific length. The transmitting device according to claim 4.

11. The transmitting device determining an arrangement of a second reference signal in a second system based on an arrangement of a first reference signal in a first system; Transmitting the second reference signal based on the determined constellation; When changing the position of at least one of the second reference signals, changing the positions of the remaining reference signals. Transmission method.

12. If a certain condition is satisfied, a position of the second reference signal is determined to be a symbol different from a symbol set in the transmitting device. The transmission method according to claim 11.

13. The condition does not depend on whether a symbol in which the first reference signal is arranged and a symbol in which the second reference signal is set overlap. The transmission method according to claim 12.

14. When a first symbol in which the first reference signal is arranged and a second symbol set for the second reference signal overlap, or when a certain condition is satisfied, a position of the second reference signal is determined to be a third symbol different from the second symbol. The transmission method according to claim 11.

15. determining whether or not the first symbol and the second symbol overlap, based on an allocation method of the data including the second reference signal and an arrangement of the first reference signal; The transmission method according to claim 14.

16. the condition does not depend on whether the first symbol and the second symbol overlap. The transmission method according to claim 14.

17. determining non-transmission of one of the two second reference signals whose time interval is equal to or less than a threshold in the determined configuration; The transmission method according to claim 11.

18. determining a position of the second reference signal to be the third symbol when a subcarrier interval set in the transmitting device is a specific value; The transmission method according to claim 14.

19. When the subcarrier spacing set in the transmitting device is 15 kHz, the position of the second reference signal is determined to be the third symbol. The transmission method according to claim 14.

20. When a PDSCH resource is notified by PDSCH mapping type B and the PDSCH resource has a specific length, the position of the second reference signal is determined to be the third symbol. The transmission method according to claim 14.

21. A process of determining an arrangement of a second reference signal in a second system based on an arrangement of a first reference signal in a first system; transmitting the second reference signal based on the determined constellation; When changing the position of at least one of the second reference signals, changing the positions of the remaining reference signals. Integrated circuits.

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