JPWO2019138562A1 - Wireless communication device - Google Patents

Abstract

It provides a new configuration that specifies the mapping of Additional DMRS when front-loaded DMRS is mapped to the first symbol of the resource allocation unit of the radio resource. In the base station device, the number of symbols in the resource allocation unit is 8 or more in the downlink radio link signal in which the front-loaded DMRS (reference signal for first demodulation) is mapped to the first symbol of the resource allocation unit, and the additional DMRS (Additional DMRS). When the number of the second demographic reference signal) is 1 or more, one additional DMRS is mapped within 3 symbols from the last symbol of the resource allocation unit.

Description

The present invention relates to a wireless communication device.

In the UMTS (Universal Mobile Telecommunication System) network, Long Term Evolution (LTE) has been specified for the purpose of further high-speed data rate and low latency (Non-Patent Document 1). In addition, a successor system to LTE is also being studied for the purpose of further widening the bandwidth and increasing the speed from LTE. The successor system of LTE includes, for example, LTE-A (LTE-Advanced), FRA (Future Radio Access), 5G (5th generation mobile communication system), 5G + (5G plus), New-RAT (Radio Access Technology), etc. There is something called.

In future wireless communication systems (for example, 5G), a demodulation reference signal for demodulating a data signal is defined, and specifications for mapping the demodulation reference signal to resources are being promoted. (See Non-Patent Document 2). The demodulation reference signal may be described as "DMRS" (Demodulation Reference Signal), "DM-RS", or "demodulation RS".

3GPP TS 36.300 v13.4.0, “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 13),” June 2016 3GPP TS 38.211 V15.0.0, “Physical channels and modulation (Release 15),” December 2017

However, in the 5G specification, when DMRS (front-loaded DMRS, reference signal for first demodulation) is mapped to the first symbol of the resource allocation unit of the radio resource, additional DMRS (Additional DMRS, second demodulation) There is a part that is not specified about the mapping position of the reference signal).

One aspect of the present invention is to specify the mapping of the additional DMRS when the DMRS is mapped to the first symbol of the resource allocation unit of the radio resource.

The wireless communication device of the present invention includes a transmission unit that transmits a downlink radio link signal in which the first demodulation reference signal is mapped to the first symbol of the resource allocation unit, the number of symbols of the resource allocation unit, and the resource allocation unit. The control unit includes a control unit that controls the mapping position of the second demographic reference signal in the resource allocation unit based on the number of the second demographic reference signals to be mapped in the above. When the number of symbols of the resource allocation unit is 8 or more and the number of the second demographic reference signals is 1 or more, one of the second symbols within 3 symbols from the last symbol of the resource allocation unit. Map the demographic reference signal of.

According to one aspect of the present invention, there is provided a new configuration that defines the mapping of the additional DMRS when the DMRS is mapped to the head symbol of the resource allocation unit of the radio resource.

It is a block diagram which shows an example of the whole structure of the radio base station which concerns on one Embodiment. It is a block diagram which shows an example of the whole structure of the user terminal which concerns on one Embodiment. It is a figure explaining the mapping type A of DMRS. It is a figure explaining the mapping type B of DMRS. It is a figure explaining the mapping position of DMRS in DL. It is a figure which showed an example of the mapping position of DMRS in DL-DMRS-add-pos "2" of mapping type B. It is a figure explaining the mapping position of D-DMRS in DL. It is a figure which showed an example of the mapping position of DMRS in DL-DMRS-add-pos "1" of mapping type B. It is a figure explaining the mapping position of DMRS in UL. It is a figure which showed an example of the mapping position of DMRS in UL-DMRS-add-pos "2" of mapping type B. It is a figure explaining the mapping position of D-DMRS in UL. It is a figure explaining an example of the frequency hopping of DMRS of UL. It is a figure explaining the mapping position of DMRS in UL. It is a figure which shows an example of the hardware composition of the radio base station 10 and the user terminal 20 which concerns on one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

(One Embodiment)
The wireless communication system according to the present embodiment includes the wireless base station 10 shown in FIG. 1 and the user terminal 20 shown in FIG. The radio base station 10 is also referred to as, for example, eNB (eNodeB) or gNB (gNodeB). The user terminal 20 is also called, for example, a UE (User Equipment). The user terminal 20 is wirelessly connected (wirelessly accessed) to the wireless base station 10.

The radio base station 10 transmits a downlink (DL: Downlink) control signal to the user terminal 20 by using a downlink control channel (for example, PDCCH: Physical Downlink Control Channel). The radio base station 10 transmits a DL data signal and a DMRS to the user terminal 20 using a downlink data channel (for example, downlink shared channel: PDSCH: Physical Downlink Shared Channel).

Further, the user terminal 20 updates the wireless base station 10 by using an uplink control channel (for example, PUCCH: Physical Uplink Control Channel) or an uplink data channel (for example, uplink shared channel: PUSCH: Physical Uplink Shared Channel). A link (UL: Uplink) control signal is transmitted. The user terminal 20 transmits a UL data signal and a DMRS to the radio base station 10 using an uplink data channel (for example, uplink shared channel: PUSCH: Physical Uplink Shared Channel).

In the wireless communication system in the present embodiment, as will be described later, one of two mapping types (mapping type A and mapping type B) is set in the DMRS mapping. Then, in the wireless communication system according to the present embodiment, some DMRS positions are defined in each of the two mapping types, and one of them is set.

The downlink channel and uplink channel transmitted and received by the radio base station 10 and the user terminal 20 are not limited to the above-mentioned PDCCH, PDSCH, PUCCH, PUSCH and the like. The downlink channel and uplink channel transmitted and received by the radio base station 10 and the user terminal 20 may be other channels such as PBCH (Physical Broadcast Channel) and RACH (Random Access Channel).

Further, in FIGS. 1 and 2, the DL and / or UL signal waveforms generated by the radio base station 10 and the user terminal 20 may be signal waveforms based on OFDM (Orthogonal Frequency Division Multiplexing) modulation. Alternatively, the DL and / or UL signal waveform may be a signal waveform based on SC-FDMA (Single Carrier-Frequency Division Multiple Access) or DFT-S-OFDM (DFT-Spread-OFDM). Alternatively, the DL and / or UL signal waveforms may be other signal waveforms. In FIGS. 1 and 2, the description of the constituent parts (for example, IFFT processing unit, CP addition unit, CP removal unit, FFT processing unit, etc.) for generating the signal waveform is omitted.

<Wireless base station>
FIG. 1 is a block diagram showing an example of the overall configuration of the radio base station 10 according to the present embodiment. The radio base station 10 includes a scheduler 101, a transmission signal generation unit 102, a coding / modulation unit 103, a mapping unit 104, a transmission unit 105, an antenna 106, a reception unit 107, a control unit 108, and a channel. It includes an estimation unit 109 and a demodulation / decoding unit 110. The radio base station 10 may have a MU-MIMO (Multi-User Multiple-Input Multiple-Output) configuration that communicates with a plurality of user terminals 20 at the same time. Alternatively, the radio base station 10 may have a SU-MIMO (Single-User Multiple-Input Multiple-Output) configuration that communicates with one user terminal 20. Alternatively, the radio base station 10 may have both SU-MIMO and MU-MIMO configurations.

The scheduler 101 schedules DL signals (DL data signals, DL control signals, DMRS, etc.) (for example, resource allocation and port allocation). In addition, the scheduler 101 schedules UL signals (UL data signals, UL control signals, DMRS, etc.) (for example, resource allocation and port allocation).

The scheduler 101 also sets the DMRS mapping type for DL and UL signals. As will be described later, the mapping type includes a mapping type A and a mapping time B. The scheduler 101 maps DMRS to predetermined symbols determined by each mapping type.

Information related to the above DMRS mapping may be described as setting information. The setting information may include other information. The setting information may be included in, for example, downlink control information (DCI).

The scheduler 101 outputs scheduling information including setting information to the transmission signal generation unit 102 and the mapping unit 104. As will be described later, the scheduler 101 may be regarded as an example of a control unit that controls a position for mapping DMRS to a DL signal.

Further, the scheduler 101 uses, for example, an MCS (Modulation and Coding Scheme) (coding rate, modulation method, etc.) of DL data signals and UL data signals based on the channel quality between the radio base station 10 and the user terminal 20. To set. The scheduler 101 outputs the set MCS information to the transmission signal generation unit 102 and the coding / modulation unit 103. The MCS is not limited to the case where the radio base station 10 is set, and the user terminal 20 may be set. When the user terminal 20 sets the MCS, the radio base station 10 may receive the MCS information from the user terminal 20 (not shown).

The transmission signal generation unit 102 generates a transmission signal (including a DL data signal and a DL control signal). For example, the DL control signal includes a DCI including scheduling information (for example, setting information) or MCS information output from the scheduler 101. The transmission signal generation unit 102 outputs the generated transmission signal to the coding / modulation unit 103.

The coding / modulation unit 103 performs coding processing and modulation processing on the transmission signal input from the transmission signal generation unit 102, for example, based on the MCS information input from the scheduler 101. The coding / modulation unit 103 outputs the modulated transmission signal to the mapping unit 104.

Based on the scheduling information (for example, DL resource allocation and setting information) input from the scheduler 101, the mapping unit 104 transmits the transmission signal input from the coding / modulation unit 103 to a predetermined radio resource (DL resource). ). Further, the mapping unit 104 maps the DMRS to a predetermined radio resource (DL resource) based on the scheduling information. The mapping unit 104 outputs the DL signal mapped to the radio resource to the transmission unit 105.

The transmission unit 105 performs transmission processing such as up-conversion and amplification on the DL signal input from the mapping unit 104, and transmits the radio frequency signal (DL signal) from the antenna 106.

The receiving unit 107 performs reception processing such as amplification and down-conversion on the radio frequency signal (UL signal) received by the antenna 106, and outputs the UL signal to the control unit 108.

The control unit 108 separates (demaps) the UL data signal and the DMRS from the UL signal input from the receiving unit 107 based on the scheduling information (UL resource allocation) input from the scheduler 101. Then, the control unit 108 outputs the UL data signal to the demodulation / decoding unit 110 and outputs the DMRS to the channel estimation unit 109.

The channel estimation unit 109 performs channel estimation using the DMRS of the UL signal, and outputs the channel estimation value, which is the estimation result, to the demodulation / decoding unit 110.

The demodulation / decoding unit 110 demodulates and decodes the UL data signal input from the control unit 108 based on the channel estimation value input from the channel estimation unit 109. The demodulation / decoding unit 110 transfers the demodulated UL data signal to the application unit (not shown). The application unit performs processing related to a layer higher than the physical layer or the MAC layer.

The block including the scheduler 101, the transmission signal generation unit 102, the coding / modulation unit 103, the mapping unit 104, and the transmission unit 105 may be regarded as an example of the radio transmission device provided in the radio base station 10. Further, the block including the receiving unit 107, the control unit 108, the channel estimation unit 109, and the demodulation / decoding unit 110 may be regarded as an example of the radio receiving device provided in the radio base station 10.

Further, the block including the control unit 108, the channel estimation unit 109, and the demodulation / decoding unit 110 is a processing unit that receives and processes the UL signal using the DMRS mapped to the time domain of the UL signal, as will be described later. You can think of it as an example.

<User terminal>
FIG. 2 is a block diagram showing an example of the overall configuration of the user terminal 20 according to the present embodiment. The user terminal 20 includes an antenna 201, a receiving unit 202, a control unit 203, a channel estimation unit 204, a demodulation / decoding unit 205, a transmission signal generation unit 206, a coding / modulation unit 207, and a mapping unit 208. And the transmission unit 209.

The receiving unit 202 performs reception processing such as amplification and down-conversion on the radio frequency signal (DL signal) received by the antenna 201, and outputs the DL signal to the control unit 203. DL signals include at least DL data signals and DMRS.

The control unit 203 separates (demaps) the DL control signal and the DMRS from the DL signal input from the reception unit 202. Then, the control unit 203 outputs the DL control signal to the demodulation / decoding unit 205, and outputs the DMRS to the channel estimation unit 204. The control unit 203 can separate the DMRS based on the DMRS setting information.

The channel estimation unit 204 performs channel estimation using the separated DMRS, and outputs the channel estimation value, which is the estimation result, to the demodulation / decoding unit 205.

The demodulation / decoding unit 205 demodulates the DL control signal input from the control unit 203. Further, the demodulation / decoding unit 205 performs a decoding process (for example, a blind detection process) on the demodulated DL control signal. The demodulation / decoding unit 205 outputs scheduling information (for example, DL / UL resource allocation) to its own unit obtained by decoding the DL control signal to the control unit 203 and the mapping unit 208, and outputs the scheduling information to the UL data signal. The MCS information is output to the coding / modulation unit 207.

Further, the demodulation / decoding unit 205 uses the channel estimation value input from the channel estimation unit 204 based on the MCS information for the DL data signal included in the DL control signal input from the control unit 203 to the control unit 203. Demodulation and decoding processing is performed on the input DL data signal. Further, the demodulation / decoding unit 205 transfers the demodulated DL data signal to the application unit (not shown). The application unit performs processing related to a layer higher than the physical layer or the MAC layer.

The transmission signal generation unit 206 generates a transmission signal (including a UL data signal or a UL control signal), and outputs the generated transmission signal to the coding / modulation unit 207.

The coding / modulation unit 207 performs coding processing and modulation processing on the transmission signal input from the transmission signal generation unit 206, for example, based on the MCS information input from the demodulation / decoding unit 205. The coding / modulation unit 207 outputs the modulated transmission signal to the mapping unit 208.

The mapping unit 208 maps the transmission signal input from the coding / modulation unit 207 to a predetermined radio resource (UL resource) based on the scheduling information (UL resource allocation) input from the demodulation / decoding unit 205. .. Further, the mapping unit 208 maps the DMRS to a predetermined radio resource (UL resource) based on the scheduling information.

The mapping of DMRS to radio resources may be controlled by, for example, control unit 203. For example, the control unit 203 may be regarded as an example of a control unit that hops the position where the DMRS is mapped to the UL signal to a different frequency at different times, as will be described later.

The transmission unit 209 performs transmission processing such as up-conversion and amplification on the UL signal (including at least UL data signal and DMRS) input from the mapping unit 208, and transmits the radio frequency signal (UL signal) from the antenna 201. Send.

The block including the transmission signal generation unit 206, the coding / modulation unit 207, the mapping unit 208, and the transmission unit 209 may be regarded as an example of the wireless transmission device provided in the user terminal 20. Further, the block including the receiving unit 202, the control unit 203, the channel estimation unit 204, and the demodulation / decoding unit 205 may be regarded as an example of the wireless receiving device provided in the user terminal 20.

Further, the block including the control unit 203, the channel estimation unit 204, and the demodulation / decoding unit 205 is a processing unit that receives and processes the DL signal using the DMRS mapped to the time domain of the DL signal, as will be described later. You can think of it as an example.

In the wireless communication system including the wireless base station 10 and the user terminal 20 described above, front-loaded DMRS is used as an example of DMRS. The front-loaded DMRS is mapped forward in the time direction in a slot (or may be called a resource unit, a subframe, etc.) which is a resource allocation unit. In other words, the first DMRS in the time direction that is mapped to the slot is called the front-loaded DMRS. By mapping the DMRS forward, the wireless communication system can reduce the processing time required for channel estimation and demodulation processing. In the following, front-loaded DMRS may be referred to as FL-DMRS, front-load DMRS or a first demodulation reference signal.

The DMRS mapping type is divided into mapping type A and mapping type B according to the mapping position of FL-DMRS. Hereinafter, two mapping types A and B will be described.

<Mapping type A>
FIG. 3A is a diagram illustrating mapping type A of DMRS. The slot shown in FIG. 3A has, for example, a configuration in which 168 resource elements (REs) are arranged 14 in the time direction and 12 in the frequency direction. 1RE is a radio resource area defined by one symbol and one subcarrier. One slot is composed of 14 symbols and 12 subcarriers.

In the following description, the 14 symbols in the time direction of the RU are referred to as SB0 to SB13 in order from the left. Further, the 12 subcarriers in the frequency direction of the RU are referred to as SC0 to SC11 in order from the bottom. The definition of a slot is not limited to the above. For example, the number of symbols in a slot can be less than 14. Further, for example, the number of subcarriers in the slot may be less than 11 or 13 or more.

The PDCCH is mapped to the two symbols SB0 and SB1 at the beginning of the slot. Alternatively, the PDCCH is mapped to the three symbols SB0, SB1, and SB2 at the beginning of the slot. In the example of FIG. 3A, the PDCCH is mapped to the two symbols SB0 and SB1 at the beginning of the slot. The mapping of PUCCH in the UL signal may be the same as that of PDCCH.

In mapping type A, FL-DMRS is mapped to the third symbol (SB2) or the fourth symbol (SB3) of the slot. That is, FL-DMRS is mapped after the PDCCH symbol in the time direction.

For example, when the PDCCH is mapped to the two symbols SB0 and SB1 as shown in FIG. 3A, the FL-DMRS is mapped to the SB2. Further, when the PDCCH is mapped to the three symbols SB0, SB1 and SB2, the FL-DMRS is mapped to the SB3.

An additional DMRS (additional DMRS) may be mapped behind the FL-DMRS in the time direction. In the example of FIG. 3A, the additional DMRS is mapped to SB11. With the additional DMRS, for example, deterioration of DMRS based on high Doppler can be suppressed, or the coverage of DMRS can be extended. In the following, the additional DMRS may be referred to as an A-DMRS or a second demodulation reference signal.

<Mapping type B>
FIG. 3B is a diagram illustrating mapping type B of DMRS. As described above, in the DMRS mapping type A, the FL-DMRS is mapped to the third symbol (SB2) or the fourth symbol (SB3) of the slot. On the other hand, in the DMRS mapping type B, FL-DMRS is mapped to the first symbol of the slot. That is, as shown in FIG. 3B, FL-DMRS is mapped to SB0.

In FIG. 3B, PDCCH or PUCCH is not mapped to the slot. When FL-DMRS is mapped to the first symbol of a slot, PDCCH or PUCCH is mapped to another slot. Also, in the example of FIG. 3B, A-DMRS is mapped to SB12.

Although FIGS. 3A and 3B illustrate the case where the number of symbols of A-DMRS is one, in the present embodiment, the number of symbols of A-DMRS is not limited to one, and may be plural. is there. Further, in FIGS. 3A and 3B, the case where DMRS is mapped to continuous subcarriers is illustrated, but in the present embodiment, DMRS may be mapped discontinuously to subcarriers.

The mapping position of DMRS is defined in each of DL and UL. Hereinafter, the mapping position of DMRS including A-DMRS will be described.

<DMRS mapping position in DL>
FIG. 4 is a diagram for explaining the mapping position of DMRS in DL. “Duration of PDSCH transmission” shown in FIG. 4 indicates the number of symbols constituting PDCCH and PDSCH in mapping type A. Further, "Duration of PDSCH transmission" indicates the number of symbols constituting the PDSCH in the mapping type B. In NR (New Radio), the number of symbols constituting the PDSCH is variable. For example, the number of symbols constituting the PDCCH can be any of 1 to 3.

The mapping position of DMRS in DL is divided into mapping type A and mapping type B as shown in "PDSCH mapping type A" and "PDSCH mapping type B" in FIG. Then, as shown in "DL-DMRS-add-pos" of FIG. 4, in each mapping type, the position of A-DMRS in each of the four cases of "0, 1, 2, 3" is defined.

“0,1,2,3” shown in the lower column of “DL-DMRS-add-pos” indicates the number of A-DMRS symbols mapped to PDSCH. For example, "0" indicates that A-DMRS is not mapped to PDSCH. “1” indicates that the number of A-DMRS symbols mapped to the PDSCH is one. In other words, FL-DMRS and one symbol A-DMRS are mapped to PDSCH. “2” indicates that the number of A-DMRS symbols mapped to the PDSCH is two. In other words, FL-DMRS and two-symbol A-DMRS are mapped to PDSCH. “3” indicates that the number of A-DMRS symbols mapped to the PDSCH is three. In other words, FL-DMRS and 3-symbol A-DMRS are mapped to PDSCH.

“L ₀ ” and a number shown in the thick line frame A1 in FIG. 4 indicate the position of the symbol to which DMRS is mapped. The mapping type A “l ₀ ” takes any of the values “2” and “3”. The mapping type B "l ₀ " takes a value of "0". That is, "l ₀ " indicates the symbol position to which FL-DMRS is mapped (see FL-DMRS in FIGS. 3A and 3B). The numbers shown in the thick line frame A1 in FIG. 4 indicate the positions of the symbols to which A-DMRS is mapped.

The position of the DMRS of each mapping type is defined by the number of symbols constituting the PDSCH. For example, (if the Duration of PDSCH Transmission shown in Fig. 4 of "11") number of symbols constituting the PDSCH is the case of "11", the mapping type A, the symbols of _{"l 0",} the _"l 0, 9" It is mapped to either a symbol or a symbol of "l ₀ , 6, 9". Further, for example, when the number of symbols constituting the PDSCH is "12" (when the Duration of PDSCH transmission shown in FIG. 4 is "12"), in the mapping type B, the symbols "l ₀ ", "l ₀ , 10" , "L ₀ , 5, 10", and "l ₀ , 3, 6, 9".

In the mapping type A, when the number of symbols constituting the PDSCH is 8 or less, A-DMRS is not mapped to the PDSCH. In the mapping type B, when the number of symbols constituting the PDSCH is 6 or less, A-DMRS is not mapped to the PDSCH.

The position of the DMRS in the DL is notified from the radio base station 10 to the user terminal 20 by, for example, DCI. For example, the radio base station 10 stores the information in the table shown in FIG. 4 in a memory as, for example, a table. The radio base station 10 refers to the table stored in the memory, and specifies the mapping type of DMRS and one of the values "0 to 3" of DL-DMRS-add-pos shown in FIG.

The user terminal 20 stores the information in the table shown in FIG. 4 in a memory as, for example, a table. The user terminal 20 refers to the memory table based on the DMRS mapping type specified by the radio base station 10 and any value of "0 to 3" of DL-DMRS-add-pos, and DMRS. Determines the position of the symbol to which is mapped.

For example, it is assumed that the radio base station 10 configures the PDSCH with 12 symbols and maps the DMRS to the position indicated by the DL-DMRS-add-pos “2” of the mapping type B (dotted frame A2 in FIG. 4). reference).

FIG. 5 is a diagram showing an example of the DMRS mapping position in DL-DMRS-add-pos “2” of mapping type B. It is assumed that the radio base station 10 configures the PDSCH with 12 symbols (SB0 to SB11) and maps DMRS to the position indicated by DL-DMRS-add-pos “2” of mapping type B (dotted line in FIG. 4). See frame A2). In this case, FL-DMRS is mapped to SB0 and A-DMRS is mapped to SB5 and SB10, for example, as shown in FIG.

As described above, the radio base station 10 notifies the user terminal 20 of the DMRS mapping position in the DL by using, for example, DCI. In the case of the above example, the radio base station 10 includes the information of DL-DMRS-add-pos “2” of mapping type B in the DCI and notifies the user terminal 20.

The user terminal 20 refers to a table (information in the table shown in FIG. 4) stored in the memory based on the information of DL-DMRS-add-pos “2” of the mapping type B included in the DCI. .. Then, the user terminal 20, FD-DMRS to _{l 0-th} symbol (SB0) is mapped, determining that A-DMRS is mapped to and SB5 and SB 10. The user terminal 20 can determine the number of symbols (12 symbols) constituting the PDSCH based on the scheduling information notified from the radio base station 10.

In the 5G specifications, the mapping position of DMRS in the frame A3 of the alternate long and short dash line of mapping type B shown in FIG. 4 is not specified. Therefore, in the present invention, the mapping position of DMRS in the frame A3 of the alternate long and short dash line of mapping type B is defined.

The DMRS in the frame A3 of the alternate long and short dash line shown in FIG. 4 is defined so that the symbol spacing to be mapped is equal or close to equal spacing, and is mapped to a certain fixed symbol. For example, when DL-DMRS-add-pos is "2", the Duration of PDSCH transmission is "2n" and "2n + 1" (n is any of 4, 5 or 6). The positions from the beginning of the slots of A-DMRS are the same.

Also, in the time direction, the last DMRS is defined to be mapped within 3 symbols from the back of the symbols constituting the PDSCH. In other words, the DMRS is specified to be mapped to both ends of the PDSCH (one end is FL-DMRS, which is mapped to the leading symbol) in the time direction as much as possible.

For example, as shown in FIG. 5, DMRS is mapped to PDSCH at 5 symbol intervals. Further, as shown in FIG. 4, the DMRS is mapped (reused) to a fixed symbol of SB3 to SB6, SB8 to SB10, and SB12. Further, as shown in FIG. 5, in the time direction, the last DMRS (A-DMRS) is mapped to SB10 in the last 3 symbols SB9, SB10, SB11 among the 12 symbols constituting the PDSCH.

By defining the DMRS mapping intervals to be equal to or close to equal intervals in this way, the accuracy of channel estimation in the PDSCH can be made uniform. In addition, by mapping DMRS to a certain symbol, collision between DMRS and data signal is avoided, the probability of collision between DMRS is increased, and DMRS is higher than when DMRS and data signal collide. The performance of channel estimation when they collide with each other can be improved on average. Further, by mapping the last DMRS within the three symbols from the back of the symbols constituting the PDSCH in the time direction, the interpolation accuracy of the channel estimation over the entire PDSCH can be improved.

<D-DMRS (Double-symbol DMRS) mapping position in DL>
Next, the mapping position of the double-symbol DMRS (hereinafter, may be referred to as D-DMRS) will be described.

In D-DMRS in DL, DMRS is mapped by two symbols in succession. For example, in mapping type A, FL-DMRS is mapped consecutively to two symbols, the third and fourth and (SB2, SB3), or the fourth and fifth and (SB3, SB4). It is continuously mapped to the symbol. A-DMRS is also mapped to two symbols in succession.

In the mapping type B as well as the mapping type A, the FL-DMRS is continuously mapped to the first and second symbols and the two symbols (SB0, SB1). A-DMRS is also mapped to two symbols in succession.

FIG. 6 is a diagram illustrating a mapping position of D-DMRS in DL. The way of reading the table shown in FIG. 6 is the same as that in FIG. However, the DMRS is mapped to a symbol indicated by "l ₀ " and a number shown in the thick line frame A11 and a symbol continuous (continuous in the time direction) with the symbol.

For example, the mapping type of D-DMRS is mapping type B, and PDCSH is composed of 12 symbols. Further, DL-DMRS-add-pos is assumed to be "1". In this case, FL-DMRS is mapped to SB0 and SB1, and A-DMRS is mapped to SB9 and SB10 (see the dotted frame A12 in FIG. 6).

FIG. 7 is a diagram showing an example of the mapping position of DMRS in DL-DMRS-add-pos “1” of mapping type B. It is assumed that the radio base station 10 configures the PDSCH with 12 symbols (SB0 to SB11) and maps DMRS to the position indicated by DL-DMRS-add-pos "1" of mapping type B (dotted line in FIG. 6). See frame A12). In this case, FL-DMRS is mapped to SB0 and SB1, and A-DMRS is mapped to SB9 and SB10, for example, as shown in FIG.

In the D-DMRS as well, the mapping position of the DMRS is notified from the radio base station 10 to the user terminal 20 as in the single DMRS. The user terminal 20 stores the information in the table shown in FIG. 6 in a memory as, for example, a table. The user terminal 20 refers to the memory table based on the DMRS mapping type specified by the radio base station 10 and any value of "0, 1" of DL-DMRS-add-pos, and D. -Determine (acquire) the position of the symbol to which DMRS is mapped.

In the 5G specifications, the mapping position of DMRS in the frame A13 of the alternate long and short dash line of mapping type B shown in FIG. 6 is not specified. Therefore, in the present invention, the mapping position of DMRS in the frame A13 of the alternate long and short dash line of mapping type B is defined.

The DMRS in the frame A13 of the alternate long and short dash line shown in FIG. 6 is defined to be mapped to a certain symbol. Also, in the time direction, the last DMRS is defined to be mapped within 3 symbols from the back of the symbols constituting the PDSCH. Further, when DL-DMRS-add-pos is "0, 1" or "2", the position from the beginning of the slot of A-DMRS where the Duration of PDSCH transmission is "10" or more is the mapping type A. And mapping type B are the same.

For example, as shown in FIG. 6, two SB9s are reused in the DMRS mapping. Further, as shown in FIG. 7, in the time direction, the last DMRS (A-DMRS) is mapped to SB10 in the last 3 symbols SB9, SB10, SB11 among the 12 symbols constituting the PDSCH.

By mapping the DMRS to a symbol that is determined to some extent in this way, the performance of channel estimation when the DMRSs collide with each other can be improved on average as compared with the case where the DMRS and the data collide with each other. Further, by mapping the last DMRS within three symbols from the back of the symbols constituting the PDSCH in the time direction, the interpolation accuracy of the channel estimation over the entire PDSCH can be improved.

As shown in FIG. 6, the case where the number of A-DMRS of D-DMRS is one is specified. That is, in A-DMRS of D-DMRS, DL-DMRS-add-pos specifies "0, 1" and does not specify 2 or more. The reason why A-DMRS of D-DMRS is not specified more than 2 is to suppress the decrease of PDSCH resources by DMRS.

For example, as shown in FIG. 7, when there is one A-DMRS of the D-DMRS, the number of symbols to which the DMRS is mapped is four, SB0, SB1, SB9, and SB10. Assuming that the number of A-DMRSs of the D-DMRS is two, the number of symbols to which the DMRS is mapped is six, so that the PDSCH resource for mapping the data signal is reduced. Therefore, A-DMRS of D-DMRS is not specified as 2 or more.

<DMRS mapping position in UL>
Next, the mapping position of DMRS in UL will be described.

FIG. 8 is a diagram illustrating a DMRS mapping position in UL. The way of reading the table shown in FIG. 8 is the same as that in FIG. However, “PUSCH duration in symbols” shown in FIG. 8 indicates the number of symbols constituting PUCCH and PUSCH when the mapping type is A. Further, "PUSCH duration in symbols" indicates the number of symbols constituting PUSCH when the mapping type is B. In NR (New Radio), the number of symbols constituting PUSCH is variable. For example, the number of symbols constituting PUCCH can be any of 1 to 3.

The position of DMRS in UL is notified from the radio base station 10 to the user terminal 20 by, for example, DCI. The user terminal 20 stores the information in the table shown in FIG. 8 in a memory as, for example, a table. The user terminal 20 refers to the table of the memory based on the information of the DMRS mapping position notified by DCI, and determines the position of the DMRS symbol to be mapped to PUSCH.

For example, it is assumed that the user terminal 20 is notified by the radio base station 10 to configure PUSCH with 12 symbols and map DMRS to the position indicated by DL-DMRS-add-pos "2" of mapping type B. (See the dotted frame A21 in FIG. 8).

FIG. 9 is a diagram showing an example of the DMRS mapping position in UL-DMRS-add-pos “2” of mapping type B. As described above, the user terminal 20 may configure the PUSCH with 12 symbols from the radio base station 10 and map the DMRS to the position indicated by the DL-DMRS-add-pos “2” of the mapping type B. Suppose you are notified. In this case, FL-DMRS is mapped to SB0 and A-DMRS is mapped to SB5 and SB10, for example, as shown in FIG. Since the radio base station 10 sets the DMRS mapping position in UL and notifies the user terminal 20 of the set information, it is possible to determine which symbol of the PUSCH received from the user terminal 20 the DMRS is mapped to. ..

The DMRS mapping position in UL may be determined by the user terminal 20. For example, the user terminal 20 may map the DMRS of the UL to the determined mapping position, and include the information of the determined mapping position in, for example, UCI (Uplink Control Information) and notify the radio base station 10. The radio base station 10 stores the information in the table shown in FIG. 8 in a memory as, for example, a table. The radio base station 10 refers to the table of the memory based on the information of the DMRS mapping position notified by UCI, and determines the position of the DMRS symbol mapped to the PUSCH.

In the 5G specifications, the mapping position of DMRS in the frame A22 of the alternate long and short dash line of mapping type B shown in FIG. 8 is not specified. Therefore, in the present invention, the mapping position of DMRS in the frame A22 of the alternate long and short dash line of mapping type B is defined.

It is stipulated that the DMRS in the frame A22 of the alternate long and short dash line shown in FIG. 8 is mapped to symbols that are mapped at equal intervals or close to equal intervals, and to some extent. Further, in the time direction, it is specified that the last DMRS is mapped within 5 symbols from the back of the symbols constituting the PUSCH. In other words, DMRS is specified to be mapped to both ends of PUSCH (one end is FL-DMRS, which is mapped to the first symbol) in the time direction as much as possible.

By defining the DMRS mapping intervals to be equal to or close to equal intervals in this way, the accuracy of channel estimation in the PUSCH can be made uniform. Further, by mapping the DMRS to a symbol that is determined to some extent, the performance of channel estimation when the DMRS collides can be improved. Further, in the time direction, by mapping the last DMRS within 5 symbols from the back of the symbols constituting the PUSCH, the interpolation accuracy of the channel estimation over the entire PDSCH can be improved.

<D-DMRS mapping position in UL>
Next, the mapping position of D-DMRS will be described.

In D-DMRS in UL, DMRS is mapped by two symbols in succession in the same manner as DMRS in DL. For example, similar to the DMRS shown in FIG. 7, DMRS is mapped by two symbols in succession in PDSCH.

FIG. 10 is a diagram illustrating a mapping position of D-DMRS in UL. The way of reading the table shown in FIG. 10 is the same as that in FIG. However, the DMRS is mapped to a symbol indicated by "l ₀ " and a number shown in the thick line frame A31 and a symbol continuous (continuous in the time direction) with the symbol.

For example, when the mapping type of D-DMRS is mapping type B, PUCSH is composed of 12 symbols, and UL-DMRS-add-pos is "1", FL-DMRS is set to SB0 and SB1. It is mapped and A-DMRS is mapped to SB9 and SB10 (see the dotted frame A32 in FIG. 10).

In the D-DMRS as well, the mapping position of the DMRS is notified from the radio base station 10 to the user terminal 20 as in the single DMRS. The user terminal 20 stores the information in the table shown in FIG. 10 in a memory as, for example, a table. The user terminal 20 refers to the memory table based on the DMRS mapping type specified by the radio base station 10 and any value of "0, 1" of UL-DMRS-add-pos, and D. -Determine the position of the symbol that maps DMRS.

In the 5G specifications, the mapping position of DMRS in the frame A33 of the alternate long and short dash line of mapping type B shown in FIG. 10 is not specified. Therefore, the mapping position of DMRS in the frame A33 of the alternate long and short dash line of mapping type B is defined.

It is stipulated that the DMRS in the frame A33 of the alternate long and short dash line shown in FIG. 10 is mapped to a certain fixed symbol. Further, in the time direction, it is specified that the last DMRS is mapped to the fourth symbol from the back of the symbols constituting the PUSCH.

By mapping the DMRS to a symbol that is determined to some extent in this way, the performance of channel estimation when the DMRSs collide with each other can be improved on average as compared with the case where the DMRS and the data collide with each other. Further, by mapping the last DMRS to the fourth symbol from the back of the symbols constituting the PUSCH in the time direction, the interpolation accuracy of the channel estimation over the entire PUSCH can be improved.

As shown in FIG. 10, the case where the A-DMRS of the D-DMRS is one is specified. That is, in A-DMRS of D-DMRS, UL-DMRS-add-pos specifies "0, 1" and does not specify 2 or more. The reason why two or more A-DMRSs of D-DMRS are not specified is to suppress the decrease of PUSCH resources by DMRS.

<DMRS frequency hopping in UL>
In UL, frequency hopping may be applied in one slot. For example, if one slot is composed of 14 symbols, one slot may be divided into two regions composed of 7 symbols and frequency hopping may be applied to the two regions.

However, the 5G specification does not specify the DMRS mapping position when frequency hopping is applied. Therefore, in the present invention, the mapping position of DMRS when frequency hopping is applied is defined.

FIG. 11 is a diagram illustrating an example of frequency hopping of DMRS of UL. As shown in FIG. 11, one slot may be divided into a first hop region located in the first half and a second hop region located in the second half in the time direction. In the example of FIG. 11, the second hop region is hopped to a frequency band lower than that of the first hop region. The second hop region may be hopped to a frequency band higher than that of the first hop region.

The 7 symbols of each hop region in FIG. 11 are referred to as SB0 to SB6 in order from the left.

PUCCH is mapped to the first two symbols (SB0 and SB1) of the first hop region of FIG. The number of symbols of PUCCH is not limited to 2 symbols, and may be 1 symbol or 3 symbols.

The DMRS is mapped in each of the first hop region and the second hop region. For example, DMRS may be mapped to SB2 and SB4 in each of the first hop region and the second hop region.

FIG. 12 is a diagram illustrating a DMRS mapping position in UL. The way of reading the table shown in FIG. 12 is the same as that in FIG. However, “PUSCH duration in symbols” shown in FIG. 12 indicates the number of symbols in the first hop region and also indicates the number of symbols in the second hop region. The DMRS shown in FIG. 11 is a case of “l ₀ = 2” of the mapping type A, and is mapped to the radio resource based on the mapping position specified by the thick line frame A41 in FIG. .. That is, the DMRS is mapped to SB2 and SB6 in the first hop region, and is mapped to SB2 and SB6 in the second hop region.

In addition, in FIG. 11, PUCCH may be mapped also in the 2nd hop region. Further, in FIG. 11, the DMRS is mapped to the same symbol position in the first hop region and the second hop region, but may be mapped to different symbol positions in the first hop region and the second hop region. .. For example, in the second hop region, DMRS may be mapped to the first symbol (SB0) instead of mapping DMRS to SB2. In this case, a table (information defining the mapping position) as shown in FIG. 12 may be prepared in each of the first hop region and the second hop region. Alternatively, in the case of mapping type A DMRS mapping to which frequency hopping is applied, the position of the DMRS in the first hop region to which the PUCCH is mapped is set based on the mapping type A shown in FIG. 12, and the PUCCH is not mapped. The position of the DMRS in the second hop region may be set based on the mapping type B shown in FIG.

The 5G specification does not specify the mapping position of DMRS of mapping types A and B in frequency hopping. Therefore, in the present invention, the mapping position of DMRS of mapping types A and B in frequency hopping is defined.

The embodiments of the present invention have been described above.

(Hardware configuration)
The block diagram used in the description of the above embodiment shows a block of functional units. These functional blocks (components) are realized by any combination of hardware and / or software. Further, the means for realizing each functional block is not particularly limited. That is, each functional block may be realized by one physically and / or logically coupled device, or directly and / or indirectly by two or more physically and / or logically separated devices. (For example, wired and / or wireless) may be connected and realized by these plurality of devices.

For example, the wireless base station 10, the user terminal 20, and the like according to the embodiment of the present invention may function as a computer that processes the wireless communication method of the present invention. FIG. 13 is a diagram showing an example of the hardware configuration of the radio base station 10 and the user terminal 20 according to the embodiment of the present invention. Even if the radio base station 10 and the user terminal 20 described above are physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like. Good.

In the following description, the word "device" can be read as a circuit, device, unit, or the like. The hardware configuration of the radio base station 10 and the user terminal 20 may be configured to include one or more of the devices shown in the figure, or may be configured not to include some of the devices.

For example, although only one processor 1001 is shown, there may be multiple processors. Further, the processing may be executed by one processor, or the processing may be executed simultaneously, sequentially, or by other methods on one or more processors. The processor 1001 may be mounted on one or more chips.

For each function of the radio base station 10 and the user terminal 20, by loading predetermined software (program) on hardware such as the processor 1001 and the memory 1002, the processor 1001 performs an calculation, and communication by the communication device 1004 or communication by the communication device 1004 or , The memory 1002 and the storage 1003 are realized by controlling the reading and / or writing of data.

Processor 1001 operates, for example, an operating system to control the entire computer. The processor 1001 may be configured by a central processing unit (CPU) including an interface with a peripheral device, a control device, an arithmetic unit, a register, and the like. For example, the above-mentioned scheduler 101, transmission signal generation units 102, 206, coding / modulation units 103, 207, mapping units 104, 208, control units 108, 203, channel estimation units 109, 204, demodulation / decoding units 110, 205. Etc. may be realized by the processor 1001.

Further, the processor 1001 reads a program (program code), a software module or data from the storage 1003 and / or the communication device 1004 into the memory 1002, and executes various processes according to these. As the program, a program that causes a computer to execute at least a part of the operations described in the above-described embodiment is used. For example, the scheduler 101 of the radio base station 10 may be realized by a control program stored in the memory 1002 and operated by the processor 1001, and may be realized for other functional blocks as well. Although it has been described that the various processes described above are executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. Processor 1001 may be mounted on one or more chips. The program may be transmitted from the network via a telecommunication line.

The memory 1002 is a computer-readable recording medium, and is composed of at least one such as a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), and a RAM (Random Access Memory). May be done. The memory 1002 may be referred to as a register, a cache, a main memory (main storage device), or the like. The memory 1002 can store a program (program code), a software module, or the like that can be executed to carry out the wireless communication method according to the embodiment of the present invention.

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

The communication device 1004 is hardware (transmission / reception device) for performing communication between computers via a wired and / or wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, or the like. For example, the above-mentioned transmitting units 105, 209, antennas 106, 201, receiving units 107, 202, and the like may be realized by the communication device 1004.

The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives an input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may have an integrated configuration (for example, a touch panel).

Further, each device such as the processor 1001 and the memory 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be composed of a single bus or may be composed of different buses between the devices.

Further, the radio base station 10 and the user terminal 20 include a microprocessor, a digital signal processor (DSP: Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), an FPGA (Field Programmable Gate Array), and the like. It may be configured to include hardware, and the hardware may realize a part or all of each functional block. For example, processor 1001 may be implemented on at least one of these hardware.

(Information notification, signaling)
Further, the notification of information is not limited to the embodiment / embodiment described in the present specification, and may be performed by other methods. For example, information notification includes physical layer signaling (for example, DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (for example, RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling, etc. It may be carried out by notification information (MIB (Master Information Block), SIB (System Information Block)), other signals, or a combination thereof. Further, the RRC signaling may be referred to as an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like.

(Adaptive system)
Each aspect / embodiment described herein includes LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G, 5G, FRA (Future Radio Access), W-CDMA. (Registered Trademarks), GSM (Registered Trademarks), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth It may be applied to (Registered Trademarks), other systems that utilize suitable systems and / or next-generation systems that are extended based on them.

(Processing procedure, etc.)
The order of the processing procedures, sequences, flowcharts, and the like of each aspect / embodiment described in the present specification may be changed as long as there is no contradiction. For example, the methods described herein present elements of various steps in an exemplary order, and are not limited to the particular order presented.

(Operation of base station)
In some cases, the specific operation performed by the base station (radio base station) in the present specification may be performed by its upper node. In a network consisting of one or more network nodes having a base station, various operations performed for communication with the terminal are performed on the base station and / or other network nodes other than the base station (for example,). It is clear that it can be done by MME (Mobility Management Entity), S-GW (Serving Gateway), etc., but not limited to these). Although the case where there is one network node other than the base station is illustrated above, it may be a combination of a plurality of other network nodes (for example, MME and S-GW).

(Input / output direction)
Information, signals, etc. can be output from the upper layer (or lower layer) to the lower layer (or upper layer). Input / output may be performed via a plurality of network nodes.

(Handling of input / output information, etc.)
The input / output information and the like may be stored in a specific location (for example, a memory), or may be managed by a management table. Input / output information and the like can be overwritten, updated, or added. The output information and the like may be deleted. The input information or the like may be transmitted to another device.

(Judgment method)
The determination may be made by a value represented by 1 bit (0 or 1), by a boolean value (Boolean: true or false), or by comparing numerical values (for example, a predetermined value). It may be done by comparison with the value).

(software)
Software is an instruction, instruction set, code, code segment, program code, program, subprogram, software module, whether called software, firmware, middleware, microcode, hardware description language, or another name. , Applications, software applications, software packages, routines, subroutines, objects, executables, execution threads, procedures, features, etc. should be broadly interpreted to mean.

Further, software, instructions, and the like may be transmitted and received via a transmission medium. For example, the software uses wired technology such as coaxial cable, fiber optic cable, twist pair and digital subscriber line (DSL) and / or wireless technology such as infrared, wireless and microwave to websites, servers, or other When transmitted from a remote source, these wired and / or wireless technologies are included within the definition of transmission medium.

(Information, signal)
The information, signals, etc. described herein may be represented using any of a variety of different techniques. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these. It may be represented by a combination of.

In addition, the terms described in the present specification and / or the terms necessary for understanding the present specification may be replaced with terms having the same or similar meanings. For example, the channel and / or symbol may be a signal. Also, the signal may be a message. Further, the component carrier (CC) may be referred to as a carrier frequency, a cell, or the like.

("System", "Network")
The terms "system" and "network" as used herein are used interchangeably.

(Parameter, channel name)
Further, the information, parameters, etc. described in the present specification may be represented by an absolute value, a relative value from a predetermined value, or another corresponding information. .. For example, the radio resource may be indexed.

The names used for the above parameters are not limited in any way. Further, mathematical formulas and the like using these parameters may differ from those expressly disclosed herein. Since the various channels (eg, PUCCH, PDCCH, etc.) and information elements (eg, TPC, etc.) can be identified by any suitable name, the various names assigned to these various channels and information elements are in any respect. However, it is not limited.

(base station)
A base station (radio base station) can accommodate one or more (eg, three) cells (also referred to as sectors). When a base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, each smaller area being a base station subsystem (eg, small indoor base station RRH: Remote). Communication services can also be provided by Radio Head). The term "cell" or "sector" refers to a part or all of the coverage area of a base station and / or base station subsystem that provides communication services in this coverage. In addition, the terms "base station,""eNB,""gNB,""cell," and "sector" may be used interchangeably herein. Base stations are sometimes referred to by terms such as fixed station, NodeB, eNodeB (eNB), gNodeB (gNB) access point, femtocell, and small cell.

(Terminal)
User terminals may be mobile stations, subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobiles, depending on the trader. It may also be referred to as a terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, UE (User Equipment), or some other suitable term.

(Meaning and interpretation of terms)
As used herein, the terms "determining" and "determining" may include a wide variety of actions. "Judgment" and "decision" are, for example, judgment, calculation, computing, processing, deriving, investigating, looking up (for example, table). , Searching in a database or another data structure), ascertaining can be considered as a "judgment" or "decision". Also, "judgment" and "decision" are receiving (for example, receiving information), transmitting (for example, transmitting information), input (input), output (output), and access. (Accessing) (for example, accessing data in memory) may be regarded as "judgment" or "decision". In addition, "judgment" and "decision" mean that "resolving", "selecting", "choosing", "establishing", "comparing", etc. are regarded as "judgment" and "decision". Can include. That is, "judgment" and "decision" may include that some action is regarded as "judgment" and "decision".

The terms "connected", "coupled", or any variation thereof, mean any direct or indirect connection or connection between two or more elements, and each other. It can include the presence of one or more intermediate elements between two "connected" or "combined" elements. The connection or connection between the elements may be physical, logical, or a combination thereof. As used herein, the two elements are by using one or more wires, cables and / or printed electrical connections, and, as some non-limiting and non-comprehensive examples, radio frequencies. It can be considered to be "connected" or "coupled" to each other by using electromagnetic energies such as electromagnetic energies having wavelengths in the region, microwave region and light (both visible and invisible) regions.

The reference signal may also be abbreviated as RS (Reference Signal) and may be referred to as a pilot depending on the applied standard. Further, the DMRS may be another corresponding name, for example, a demodulation RS or a DM-RS.

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

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

As long as "including," "comprising," and variations thereof are used herein or in the claims, these terms are as comprehensive as the term "comprising." Intended to be targeted. Furthermore, the term "or" as used herein or in the claims is intended not to be an exclusive OR.

The radio frame may consist of one or more frames in the time domain. Each one or more frames in the time domain may be referred to as a subframe, a time unit, or the like. Subframes may further consist of one or more slots in the time domain. The slot may further be composed of one or more symbols (OFDMA (Orthogonal Frequency Division Multiplexing) symbol, SC-FDMA (Single Carrier-Frequency Division Multiple Access) symbol, etc.) in the time domain.

Wireless frames, subframes, slots, minislots, and symbols all represent the time unit in which a signal is transmitted. Radio frames, subframes, slots, minislots, and symbols may have different names corresponding to each.

For example, in an LTE system, a base station schedules each mobile station to allocate radio resources (frequency bandwidth that can be used by each mobile station, transmission power, etc.). The minimum scheduling time unit may be called TTI (Transmission Time Interval).

For example, one subframe may be referred to as TTI, a plurality of consecutive subframes may be referred to as TTI, one slot may be referred to as TTI, and one minislot may be referred to as TTI.

A resource unit is a resource allocation unit in the time domain and the frequency domain, and may include one or more consecutive subcarriers in the frequency domain. Further, the time domain of the resource unit may include one or more symbols, and may have a length of 1 slot, 1 mini slot, 1 subframe, or 1 TTI. One TTI and one subframe may each be composed of one or a plurality of resource units. Further, the resource unit may be referred to as a resource block (RB: Resource Block), a physical resource block (PRB: Physical RB), a PRB pair, an RB pair, a scheduling unit, a frequency unit, or a subband. Further, the resource unit may be composed of one or a plurality of REs. For example, 1RE may be a resource of a unit smaller than the resource unit that is the resource allocation unit (for example, the smallest resource unit), and is not limited to the name RE.

The structure of the radio frame described above is merely an example, and the number of subframes contained in the radio frame, the number of slots contained in the subframe, the number of mini slots contained in the subframe, and the symbols and resource blocks contained in the slots. The number and the number of subcarriers contained in the resource block can be changed in various ways.

Throughout this disclosure, if articles are added by translation, for example, a, an, and the in English, unless the context clearly indicates that these articles are not. It shall include more than one.

(Variations of modes, etc.)
Each aspect / embodiment described in the present specification may be used alone, in combination, or may be switched and used according to the execution. Further, the notification of predetermined information (for example, the notification of "being X") is not limited to the explicit one, but is performed implicitly (for example, the notification of the predetermined information is not performed). May be good.

Although the present invention has been described in detail above, it is clear to those skilled in the art that the present invention is not limited to the embodiments described herein. The present invention can be implemented as modifications and modifications without departing from the spirit and scope of the present invention as defined by the claims. Therefore, the description of the present specification is for the purpose of exemplification and does not have any limiting meaning to the present invention.

10 Radio base station 20 User terminal 101 Scheduler 102, 206 Transmission signal generation unit 103, 207 Coding / modulation unit 104, 208 Mapping unit 105, 209 Transmission unit 106, 201 Antenna 107, 202 Reception unit 108, 203 Control unit 109, 204 channel estimation unit 110,205 demodulation / decoding unit

Claims (6)

A transmitter that transmits a downlink radio link signal in which the first demodulation reference signal is mapped to the first symbol of the resource allocation unit, and
The mapping position of the second demodulation reference signal in the resource allocation unit is controlled based on the number of symbols in the resource allocation unit and the number of second demodulation reference signals mapped in the resource allocation unit. Control unit and
Equipped with
The control unit
When the number of symbols of the resource allocation unit is 8 or more and the number of the second demodulation reference signals is 1 or more, one of the second symbols within 3 symbols from the last symbol of the resource allocation unit. Map the demodulation reference signal,
Wireless communication device. The control unit
When the number of the second demodulation reference signals is 2 or more, the first and second demodulation reference signals are mapped at equal intervals.
The wireless communication device according to claim 1. The control unit
When the number of the second demodulation reference signals of the resource allocation unit is 2, the number of symbols of the resource allocation unit is 2n or (2n + 1), and (n is any of 4, 5, and 6). Or), the second demodulation reference signal is mapped to the same position from the beginning of the resource allocation unit.
The wireless communication device according to claim 1. A transmitter that transmits a downlink radio link signal in which the first demodulation reference signal is continuously mapped by two symbols from the beginning of the resource allocation unit, and
The mapping position of the second demodulation reference signal in the resource allocation unit is controlled based on the number of symbols in the resource allocation unit and the number of second demodulation reference signals mapped in the resource allocation unit. Control unit and
Equipped with
The control unit
When the number of symbols in the resource allocation unit is 8 or more and the number of the second demodulation reference signals is 1 or more, the second demodulation reference signals are mapped by two symbols in succession, and the above. Map at least one of the second demodulation reference signals within 3 symbols of the last symbol of the resource allocation unit.
Wireless communication device. A transmitter that transmits an uplink radio link signal in which the first demodulation reference signal is mapped to the first symbol of the resource allocation unit, and
The mapping position of the second demodulation reference signal in the resource allocation unit is controlled based on the number of symbols in the resource allocation unit and the number of second demodulation reference signals mapped in the resource allocation unit. Control unit and
Equipped with
The control unit
When the number of symbols in the resource allocation unit is 14 and the number of reference signals for the second demodulation is 1 or more, one demodulation of the second demodulation within 5 symbols from the last symbol of the resource allocation unit. To map the reference signal,
Wireless communication device. A transmitter that transmits an uplink radio link signal in which the first demodulation reference signal is continuously mapped by two symbols from the beginning of the resource allocation unit, and
The mapping position of the second demodulation reference signal in the resource allocation unit is controlled based on the number of symbols in the resource allocation unit and the number of second demodulation reference signals mapped in the resource allocation unit. Control unit and
Equipped with
The control unit
When the number of symbols in the resource allocation unit is 13 or more and the number of the second demodulation reference signals is 1, the second demodulation reference signals are mapped by two symbols in succession, and the above. Map at least one of the second demodulation reference signals within 5 symbols of the last symbol of the resource allocation unit.
Wireless communication device.

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