KR20230138378A - Method and apparatus for transmitting downlink reference signal in mobile communication - Google Patents

Abstract

This specification proposes a method for transmitting and receiving a downlink reference signal for radio channel demodulation in a 5G radio access network or NR.

Description

Method and device for transmitting a downlink reference signal in a wireless mobile communication system {METHOD AND APPARATUS FOR TRANSMITTING DOWNLINK REFERENCE SIGNAL IN MOBILE COMMUNICATION}

This specification relates to the 3GPP 5G NR system.

As more and more communication devices require larger communication traffic with the passage of time, the next-generation 5G system, which is an improved wireless broadband communication system than the existing LTE system, is required. In this next-generation 5G system, called NewRAT, communication scenarios are divided into Enhanced Mobile BroadBand (eMBB)/Ultra-reliability and low-latency communication (URLLC)/Massive Machine-Type Communications (mMTC).

Here, eMBB is a next-generation mobile communication scenario with characteristics such as High Spectrum Efficiency, High User Experienced Data Rate, and High Peak Data Rate, and URLLC is a next-generation mobile communication scenario with characteristics such as Ultra Reliable, Ultra Low Latency, and Ultra High Availability. (e.g., V2X, Emergency Service, Remote Control), mMTC is a next-generation mobile communication scenario with Low Cost, Low Energy, Short Packet, and Massive Connectivity characteristics. (e.g., IoT).

Accordingly, the disclosure of this specification aims to solve the above-mentioned problems.

This specification proposes a method for transmitting and receiving a downlink reference signal for radio channel demodulation in a 5G wireless access network (hereinafter referred to as NR [New Radio] in the present invention). In particular, we propose a NR PDCCH DM-RS transmission method to efficiently apply Dynamic Spectrum Sharing (DSS) technology to support coexistence of LTE and NR.

According to the disclosure of this specification, data channels can be efficiently scheduled in a wireless mobile communication system.

Figure 1 illustrates the structure of a radio frame used in NR.
Figure 2 illustrates the slot structure of an NR frame.
Figure 3 illustrates the structure of a self-contained slot.
Figure 4 shows a block diagram of a processor on which the disclosure of the present specification is implemented.
Figure 5 shows a wireless communication device according to an embodiment of the present specification.
Figure 6 illustrates a block diagram of a network node according to an embodiment of the present specification.
Figure 7 illustrates a block diagram of a communication device according to an embodiment of the present specification.

Although this specification describes embodiments using an LTE system, an LTE-A system, and an NR system, these embodiments may be applied to any communication system that falls within the above definition.

In addition, in this specification, the name of the base station may be used as a comprehensive term including remote radio head (RRH), eNB, transmission point (TP), reception point (RP), relay, etc.

The 3GPP-based communication standard includes downlink physical channels corresponding to resource elements that carry information originating from the upper layer, and downlink physical channels corresponding to resource elements that are used by the physical layer but do not carry information originating from the upper layer. Physical signals are defined. For example, a physical downlink shared channel (PDSCH), a physical broadcast channel (PBCH), a physical multicast channel (PMCH), and a physical control format indicator channel (physical control). format indicator channel (PCFICH), physical downlink control channel (PDCCH), and physical hybrid ARQ indicator channel (PHICH) are defined as downlink physical channels, and reference signals and synchronization signals are defined as downlink physical signals. A reference signal (RS), also called a pilot, refers to a signal with a predefined special waveform known to both the gNB and the UE, for example, cell specific RS (cell specific RS), UE- UE-specific RS (UE-RS), positioning RS (PRS), and channel state information RS (CSI-RS) are defined as downlink reference signals. The 3GPP LTE/LTE-A standard corresponds to uplink physical channels corresponding to resource elements carrying information originating from upper layers, and resource elements used by the physical layer but not carrying information originating from upper layers. Uplink physical signals are defined. For example, a physical uplink shared channel (PUSCH), a physical uplink control channel (PUCCH), and a physical random access channel (PRACH) are used as uplink physical channels. A demodulation reference signal (DMRS) for uplink control/data signals and a sounding reference signal (SRS) used for uplink channel measurement are defined.

In this specification, PDCCH (Physical Downlink Control CHannel) / PCFICH (Physical Control Format Indicator CHannel) / PHICH ((Physical Hybrid automatic retransmit request Indicator CHannel) / PDSCH (Physical Downlink Shared CHannel) are respectively DCI (Downlink Control Information) / CFI ( Control Format Indicator)/Downlink ACK/NACK (ACKnowlegement/Negative ACK)/Refers to a set of time-frequency resources or a set of resource elements carrying downlink data. Also, PUCCH (Physical Uplink Control CHannel)/PUSCH (Physical Uplink Shared CHannel)/PRACH (Physical Random Access CHannel) refers to a set of time-frequency resources or a set of resource elements that carry UCI (Uplink Control Information)/uplink data/random access signal, respectively.

Figure 1 illustrates the structure of a radio frame used in NR.

In NR, uplink and downlink transmission consists of frames. A wireless frame is 10ms long and is defined as two 5ms half-frames (HF). A half-frame is defined as five 1ms subframes (Subframe, SF). A subframe is divided into one or more slots, and the number of slots in a subframe depends on SCS (Subcarrier Spacing). Each slot contains 12 or 14 OFDM(A) symbols depending on the cyclic prefix (CP). Normally when CP is used, each slot contains 14 symbols. When extended CP is used, each slot contains 12 symbols. Here, the symbol may include an OFDM symbol (or CP-OFDM symbol) and an SC-FDMA symbol (or DFT-s-OFDM symbol).

Table 1 illustrates that when a normal CP is used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS.

SCS(15* ^2u ) N- ^slot _symbol N ^{frame, u} _slot N ^subframe,u _slot 15 KHz (u = 0) 14 10 One 30 KHz (u = 1) 14 20 2 60 KHz (u = 2) 14 40 4 120 KHz (u =3) 14 80 8 240 KHz (u =4) 14 160 16

N ^slot _symb : Number of symbols in a slotN ^frame,u _slot : Number of slots in a frame

N ^subframe,u _slot : Number of slots in the subframe

Table 2 illustrates that when an extended CP is used, the number of symbols per slot, the number of slots per frame, and the number of slots per subframe vary depending on the SCS.

SCS (15* ^2u ) N- ^slot _symbol N ^{frame, u} _slot N ^subframe,u _slot 60KHz (u=2) 12 40 4

In the NR system, OFDM(A) numerology (e.g., SCS, CP length, etc.) may be set differently between multiple cells merged into one UE. Accordingly, the (absolute time) interval of time resources (e.g., SF, slot, or TTI) (for convenience, collectively referred to as TU (Time Unit)) consisting of the same number of symbols may be set differently between merged cells.

Figure 2 illustrates the slot structure of an NR frame.

A slot includes a plurality of symbols in the time domain. For example, in the case of normal CP, one slot contains 14 symbols, but in the case of extended CP, one slot contains 12 symbols. A carrier wave includes a plurality of subcarriers in the frequency domain. RB (Resource Block) is defined as multiple (eg, 12) consecutive subcarriers in the frequency domain. BWP (Bandwidth Part) is defined as a plurality of consecutive (P)RBs in the frequency domain and may correspond to one numerology (e.g., SCS, CP length, etc.). A carrier wave may contain up to N (e.g., 4) BWPs. Data communication is performed through an activated BWP, and only one BWP can be activated for one terminal. Each element in the resource grid is referred to as a Resource Element (RE), and one complex symbol can be mapped.

Figure 3 illustrates the structure of a self-contained slot.

In the NR system, a frame features a self-contained structure in which a DL control channel, DL or UL data, and UL control channel can all be included in one slot. For example, the first N symbols in a slot may be used to transmit a DL control channel (hereinafter, DL control area), and the last M symbols in a slot may be used to transmit a UL control channel (hereinafter, UL control area). N and M are each integers greater than or equal to 0. The resource area (hereinafter referred to as data area) between the DL control area and the UL control area may be used for DL data transmission or may be used for UL data transmission. As an example, the following configuration may be considered. Each section is listed in chronological order.

1. DL only configuration

2. UL only configuration

3. Mixed UL-DL configuration

- DL area + GP (Guard Period) + UL control area

- DL control area + GP + UL area

DL area: (i) DL data area, (ii) DL control area + DL data area

UL area: (i) UL data area, (ii) UL data area + UL control area

PDCCH may be transmitted in the DL control area, and PDSCH may be transmitted in the DL data area. PUCCH may be transmitted in the UL control area, and PUSCH may be transmitted in the UL data area. In the PDCCH, Downlink Control Information (DCI), for example, DL data scheduling information, UL data scheduling information, etc. may be transmitted. In PUCCH, Uplink Control Information (UCI), for example, Positive Acknowledgment/Negative Acknowledgment (ACK/NACK) information for DL data, Channel State Information (CSI) information, Scheduling Request (SR), etc. may be transmitted. GP provides a time gap during the process of the base station and the terminal switching from transmission mode to reception mode or from reception mode to transmission mode. Some symbols at the point of transition from DL to UL within a subframe may be set to GP.

The 5G wireless mobile communication system NR defined by 3GPP supports DSS (Dynamic Spectrum Sharing), a frequency sharing technology for coexistence with LTE. In other words, it is a method for efficiently migrating any LTE frequency band and utilizing it as an NR frequency band in the future. For NR signal transmission, the remaining resources excluding the radio resources used for LTE signal transmission in the corresponding frequency band are utilized. Defined to support DSS technology for use. For example, when transmitting PDSCH, a downlink data channel, any NR base station can set a rate match pattern for LTE CRS to transmit PDSCH through REs (Resource Elements) other than those used for LTE CRS transmission. It has been defined to

However, in the case of PDCCH for transmitting Downlink Control Information (DCI) such as scheduling control information, NR PDCCH transmission is defined to be restricted for symbols on which LTE CRS transmission is performed. Accordingly, NR PDCCH can be transmitted only through symbols #1 and #2 or symbol #2 depending on the number of LTE CRS antenna ports among the first three symbols of any DL slot: symbols #0, #1, and #2. Specifically, when the number of LTE CRS antenna ports is 1 or 2, NR PDCCH transmission is possible through symbol #1 and symbol #2, and when the number of LTE CRS antenna ports is 4, NR PDCCH transmission is possible only through symbol #2.

This limitation of OFDM symbols capable of NR PDCCH transmission can cause a shortage of NR PDCCH capacity, and as a solution to this, the need for technology to support NR PDCCH transmission is increasing for OFDM symbols in which LTE CRS transmission is performed. there is.

In this specification, we propose a method for supporting NR PDCCH transmission in a symbol where LTE CRS transmission occurs. In particular, when the radio resources allocated for NR PDCCH transmission include LTE CRS, how to set rate matching for the LTE CRS, and RE(s) and LTE CRS in which DM-RS transmission for demodulation of NR PDCCH is performed If overlap occurs between RE(s) where transmission is performed, a method to resolve this is proposed.

Point 1: LTE CRS rate matching configuration

When the base station transmits NR PDCCH and the terminal monitors and receives NR PDCCH, it is defined not to transmit or receive PDCCH payload or PDCCH DM-RS for RE(s) used for LTE CRS transmission, and the base station You can set it.

To support DSS, a random NR base station transmitted LTE CRS rate matching pattern setting information for the NR PDSCH to the terminal in the corresponding cell through RRC signaling. That is, RRC IE (Information Elements) " RateMatchPatternLTE-CRS " for transmitting LTE CRS rate matching configuration information for NR PDSCH has been defined, and the corresponding RRC IE has been defined to include the information below. Accordingly, any NR terminal is defined not to expect reception of the NR PDSCH for the RE(s) used for the corresponding LTE CRS transmission when receiving the NR PDSCH. Likewise, rate matching can be defined for NR PDCCH reception according to the corresponding " RateMatchPatternLTE-CRS ".

RateMatchPatternLTE-CRS information element

--ASN1START
-- TAG-RATEMATCHPATTERNLTE-CRS-START

RateMatchPatternLTE-CRS ::= SEQUENCE {
carrierFreqDL INTEGER (0..16383);
carrierBandwidthDL ENUMERATED {n6, n15, n25, n50, n75, n100, spare2, spare1},
mbsfn-SubframeConfigList EUTRA-MBSFN-SubframeConfigList OPTIONAL, -- Need M
nrofCRS-Ports ENUMERATED {n1, n2, n4},
v-Shift ENUMERATED {n0, n1, n2, n3, n4, n5}
}

LTE-CRS-PatternList-r16 ::= SEQUENCE (SIZE (1..maxLTE-CRS-Patterns-r16)) OF RateMatchPatternLTE-CRS

-- TAG-RATEMATCHPATTERNLTE-CRS-STOP
--ASN1STOP

RateMatchPatternLTE-CRS field descriptions carrierBandwidthDL BW of the LTE carrier in number of PRBs (see TS 38.214 [19], clause 5.1.4.2). carrierFreqDL Center of the LTE carrier (see TS 38.214 [19], clause 5.1.4.2). mbsfn-SubframeConfigList LTE MBSFN subframe configuration (see TS 38.214 [19], clause 5.1.4.2). nrofCRS-Ports Number of LTE CRS antenna port to rate-match around (see TS 38.214 [19], clause 5.1.4.2). v-Shift Shifting value v-shift in LTE to rate match around LTE CRS (see TS 38.214 [19], clause 5.1.4.2).

At this time, as a method to apply LTE CRS rate matching to the corresponding NR PDCCH, LTE CRS rate matching to the NR PDCCH can be set in CORESET units or search space units. In other words, when configuring CORESET for an arbitrary terminal at the NR base station, it can be defined to include indication information for applying NR PDCCH rate matching according to the corresponding " RateMatchPatternLTE-CRS ". Specifically, an information area for indicating whether to apply LTE CRS rate matching according to " RateMatchPatternLTE-CRS " is defined in the RRC IE for setting CORESET for any terminal, and based on this, NR PDCCH is transmitted through the corresponding CORESET. determine whether to apply LTE CRS rate matching, or directly include carrierFreqDL, carrierBandwidthDL, mbsfn-SubframeConfigList information included in the above " RateMatchPatternLTE-CRS " in the relevant CORESET setting information, and LTE for NR PDCCH based on this CRS rate matching can be defined.

Alternatively, when configuring a search space for a random terminal at the NR base station, it can be defined to include indication information for applying NR PDCCH rate matching according to " RateMatchPatternLTE-CRS ". Specifically, in the RRC IE for setting the search space for any terminal, an information area is defined to indicate whether or not to apply CRS rate matching according to the " RateMatchPatternLTE-CRS " setting, and based on this, transmission is performed through the search space. Decide whether to apply LTE CRS rate matching to NR PDCCH, or directly include carrierFreqDL, carrierBandwidthDL, mbsfn-SubframeConfigList information included in " RateMatchPatternLTE-CRS " above in the search space setting information, and LTE CRS based on this. It can be defined so that rate matching occurs.

As another method for applying LTE CRS rate matching to the corresponding NR PDCCH, it can be defined so that whether or not LTE CRS rate matching to the corresponding NR PDCCH is determined on a per-terminal basis.

As an example of this, any UE can implicitly define whether LTE CRS rate matching for the NR PDCCH is determined according to the UE capability configuration information and the “ RateMatchPatternLTE-CRS ” configuration above. Specifically, the base station and the terminal can exchange information about whether the terminal supports LTE CRS rate matching for the NR PDCCH through UE capability configuration information. Based on this, LTE CRS rate matching support for NR PDCCH is determined in any terminal. At this time, if any terminal supports LTE CRS rate matching for the NR PDCCH, LTE CRS rate matching for the NR PDCCH is determined depending on whether the “ RateMatchPatternLTE-CRS ” setting is set. That is, in the case of a terminal for which arbitrary LTE CRS pattern information is set through reception of the above " RateMatchPatternLTE-CRS ", rate matching for LTE CRS RE(s) can be defined to be assumed when receiving NR PDCCH according to the information. . That is, if the NR PDCCH transmission for the corresponding terminal includes RE(s) in which LTE CRS transmission is performed according to the above " RateMatchPatternLTE-CRS ", the corresponding NR PDCCH transmission is rate matching for the RE(s) in which LTE CRS transmission is performed. It can be defined so that this can be achieved.

Or, define an additional information area to indicate whether to set rate matching for NR PDCCH in the " RateMatchPatternLTE-CRS ", so that the base station explicitly signals whether to apply LTE CRS rate matching to NR PDCCH through the information area. It can be defined. Accordingly, for any terminal that supports LTE CRS rate matching for NR PDCCH, the base station additionally includes explicit setting information about whether to apply LTE CRS rate matching to the " RateMatchPatternLTE-CRS " for the NR PDCCH for that terminal. and transmit it to the corresponding terminal. Accordingly, the terminal can be defined to decide whether to apply rate matching for LTE CRS when receiving the NR PDCCH according to the corresponding “ RateMatchPatternLTE-CRS ”.

Point 2: PDCCH DM-RS collision handling

CORESET settings for PDCCH transmission for any NR terminal can be set up to 3 symbols on the time axis. Accordingly, in the case of CORESET setting for PDCCH transmission including PDSCH/PUSCH scheduling control information based on arbitrary mapping type A, up to the first 3 symbols of any NR slot on the time axis can be done.

DM-RS for NR PDCCH transmission on the frequency axis is transmitted through three subcarriers #1, #5, and #9 among the 12 subcarriers from #0 to #11 that make up one random PRB, as shown in Figure 1 below. is transmitted.

On the other hand, in the case of LTE CRS, when the number of antenna ports is 1 or 2, it is transmitted through the first OFDM symbol, when the number of antenna ports is 4, it is transmitted through the first and second OFDM symbols, and on the frequency axis, when the number of antenna ports is 1 , it is transmitted through subcarriers #0 and #6, and when the number of antenna ports is 2 or 4, it is transmitted through subcarriers #0, #3, #6, and #9, respectively. However, in the case of the frequency axis, transmission is performed by shifting on the frequency axis according to the vshift value according to the PCID.

When NR PDCCH and LTE CRS are transmitted through the same symbol within one PRB, the case in which collision occurs between the above NR PDCCH DM-RS and LTE CRS is as follows depending on the LTE CRS port number.

Subcarrier
index
in a PRB RE(s) for NR PDCCH DM-RS RE(s)
for
LTE CRS Subcarrier
index
in a PRB RE(s) for NR PDCCH DM-RS RE(s)
for
LTE CRS Subcarrier
index
in a PRB RE(s) for NR PDCCH DM-RS RE(s)
for
LTE CRS 11 11 11 10 10 10 9 NR-DMRS 9 NR-DMRS 9 NR-DMRS 8 8 8 port 0 7 7 port 0 7 6 port 0 6 6 5 NR-DMRS 5 NR-DMRS 5 NR-DMRS 4 4 4 3 3 3 2 2 2 port 0 One NR-DMRS One NR-DMRS port 0 One NR-DMRS 0 port 0 0 0

Subcarrier
index
in a PRB RE(s) for NR PDCCH DM-RS RE(s)
for
LTE CRS Subcarrier
index
in a PRB RE(s) for NR PDCCH DM-RS RE(s)
for
LTE CRS Subcarrier
index
in a PRB RE(s) for NR PDCCH DM-RS RE(s)
for
LTE CRS 11 11 11 port 0 10 10 port 0 10 9 NR-DMRS port 0 9 NR-DMRS 9 NR-DMRS 8 8 8 7 7 7 6 6 6 5 NR-DMRS 5 NR-DMRS 5 NR-DMRS port 0 4 4 port 0 4 3 port 0 3 3 2 2 2 One NR-DMRS One NR-DMRS One NR-DMRS 0 0 0

(a) When the number of LTE CRS antenna ports is 1, collision case according to vshift value

Subcarrier
index
in a PRB RE(s) for NR PDCCH DM-RS RE(s)
for
LTE CRS Subcarrier
index
in a PRB RE(s) for NR PDCCH DM-RS RE(s)
for
LTE CRS Subcarrier
index
in a PRB RE(s) for NR PDCCH DM-RS RE(s)
for
LTE CRS 11 11 11 port 1 or 3 10 10 port 1 or 3 10 9 NR-DMRS port 1 or 3 9 NR-DMRS 9 NR-DMRS 8 8 8 port 0 or 2 7 7 port 0 or 2 7 6 port 0 or 2 6 6 5 NR-DMRS 5 NR-DMRS 5 NR-DMRS port 1 or 3 4 4 port 1 or 3 4 3 port 1 or 3 3 3 2 2 2 port 0 or 2 One NR-DMRS One NR-DMRS port 0 or 2 One NR-DMRS 0 port 0 or 2 0 0

(a) When the number of LTE CRS antenna ports is 2 or 4, collision case according to vshift value

As can be seen in the figure above, there are various cases in which collision between NR PDCCH DM-RS and LTE CRS occurs depending on the number of LTE CRS antenna ports (=1, 2, or 4) during the first 3 symbols of any DL slot. It may appear.

Scheme 1. NR PDCCH DM-RS shifting on frequency domain

If overlap occurs with the LTE CRS RE(s) for the RE(s) allocated for NR PDCCH DM-RS transmission, the NR PDCCH DM-RS transmitted through the RE(s) where the overlap occurred is shifted in the frequency domain. It can be defined as:

At this time, as the first method of frequency shifting for DM-RS, among DM-RS transmitted through subcarriers (#1, #5, #9) of each PRB in a random symbol, only the RE of the subcarrier where a collision occurred with the LTE CRS occurred. In the frequency domain, it can be defined to shift by 1 in the positive direction. In other words, if the subcarrier index where overlap between DM-RS and CRS occurs is N, the DM-RS to be transmitted at the corresponding subcarrier index #N can be transmitted through subcarrier #N+1. Specifically, NR PDCCH DM-RS transmission is performed in one PRB through subcarriers #1, #5, and #9. At this time, if a collision occurs with LTE CRS transmission in subcarrier #1, only the DM-RS transmitted through subcarrier #1 can be defined to be shifted and transmitted to #2. In this case, the corresponding symbol is transmitted through subcarrier indexes #2, #5, and #9 in each PRB of the NR DM-RS. Even if a collision occurs with the LTE CRS in the remaining #5 or #9, 1 subcarrier shifting can be defined in the positive direction only for DM-RS transmitted through the corresponding subcarrier. That is, as a shifted DM-RS pattern within a random PRB, the set of subcarrier indices where DM-RS transmission is performed in the corresponding PRB is (#2, #5, #9), (#1, #6, #9), respectively. It can be defined as (#1, #5, #10).

As a second method of frequency shifting for DM-RS, among DM-RS transmitted through the subcarriers (#1, #5, #9) of each PRB in a random symbol, only the RE of the subcarrier where a collision occurred with the LTE CRS occurs is the frequency. The domain can be defined to shift by 1 in the negative direction. In other words, if the subcarrier index where overlap between DM-RS and CRS occurs is N, it can be defined to transmit DM-RS through subcarrier #N-1. Specifically, NR PDCCH DM-RS transmission is performed in one PRB through subcarriers #1, #5, and #9. At this time, if a collision occurs with LTE CRS transmission in subcarrier #1, only the DM-RS transmitted through subcarrier #1 can be defined to be shifted and transmitted to #0. In this case, the corresponding symbol is transmitted through subcarrier indexes #0, #5, and #9 in each PRB of the NR DM-RS. Even if a collision occurs with the LTE CRS in the remaining #5 or #9, 1 subcarrier shifting can be defined in the negative direction only for DM-RS transmitted through the corresponding subcarrier. That is, as a shifted DM-RS pattern within a random PRB, the set of subcarrier indices where DM-RS transmission occurs in the corresponding PRB is (#0, #5, #9), (#1, #4, #9), respectively. It can be defined as (#1, #5, #8).

As a third method of frequency shifting for DM-RS, when the number of LTE CRS antenna ports is 1 and a collision occurs with LTE CRS in any subcarrier, not only the subcarrier of the DM-RS RE but also the entire DM-RS RE in the PRB It can be defined to shift in the frequency domain. That is, in the figure (a) above, when the vshift values of LTE CRS are 1, 3, and 5, respectively, collision occurs in subcarriers #1, #5, and #9, and in this case, the NR DM-RS positive direction in the corresponding symbol It can be defined to transmit through (#2, #6, #10) by shifting, or to transmit through (#0, #4, #8) by shifting in the negative direction.

To apply frequency shifting (i.e., subcarrier shifting) to the NR PDCCH DM-RS above, the base station provides the terminal with information on the frequency at which LTE CRS transmission occurs (e.g. carrierFreqDL information, carrierBandwidthDL information, etc.) and LTE CRS antenna when setting a random CORESET. It can be defined to include new port number information (i.e., nrofCRS-Ports information) and vshift information. Based on this, any NR terminal obtains information on REs where LTE CRS transmission occurs, and when LTE CRS transmission is expected from any NR PDCCH DM-RS RE(s), the various DM-RS shifting patterns described above are used. You can apply one of the DM-RS shifting patterns. The shifting pattern to be applied at this time can be defined by one of the above methods. In other words, the same shifting method can be defined to be applied to all DM-RS and CRS collision cases in Figures (a) and (b) above. Alternatively, a separate shifting method can be defined to be applied for each collision case. For example, if the number of LTE CRS ports is 1 (i.e., the case corresponding to figure (a) above), the third method above is used. If applied and the number of LTE CRS ports is 2 or 4, it can be defined to apply the first or second method. That is, the NR PDCCH DM-RS shifting pattern can be defined and mapped for each collision case above.

Alternatively, the base station can define the DM-RS shifting pattern information to be set directly through higher layer signaling. For example, it can be defined to include DM-RS shifting pattern information in addition to the CORESET setting information above.

Scheme 2. NR PDCCH DM-RS shifting on time domain

If a collision occurs between the corresponding NR PDCCH DM-RS transmission and LTE CRS transmission in one or more RE(s) for the RE(s) allocated for NR PDCCH DM-RS transmission in any symbol, NR -PDCCH DM-RS The transmission symbol can be defined to shift. Specifically, depending on the duration of CORESET (number of symbols for CORESET) and the number of LTE CRS ports, collision between NR PDCCH DM-RS and LTE CRS may occur in one symbol or two symbols. In this case, it can be defined to shift the PDCCH DM-RS transmission symbol of the corresponding CORESET by the number of symbols in which the collision occurs.

For example, if the CORESET duration is set to 3 (i.e., when PDCCH is transmitted through the first 3 symbols of a random slot) and the number of CRS ports is 2, the transmission between NR PDCCH DM-RS and LTE CRS in the first symbol Collision may occur. In this case, the NR PDCCH DM-RS transmitted through the first, second, and third symbols, respectively, can be defined to be shifted by 1 symbol and transmitted through the second, third, and fourth symbols.

However, in the case of time domain shifting, it may be limited within the set CORESET duration. That is, in the above example, when the CORESET duration is set to 3 and the number of LTE CRS ports is 2, if time shifting is limited within the CORESET duration, a collision occurs between the NR PDCCH DM-RS and LTE CRS, unlike the example above. It can be defined to transmit the NR PDCCH DM-RS through the second and third symbols, excluding the first symbol. That is, in the case of NR PDCCH DM-RS, the existing pattern can be maintained on the existing frequency axis, but transmission can be defined so that transmission occurs only in the remaining symbols excluding the symbols in which LTE CRS transmission occurs.

Scheme 3. NR PDCCH DM-RS puncturing

When LTE CRS transmission is performed on a RE(s) allocated for NR PDCCH DM-RS transmission in a random symbol, the RE(s) can be defined to puncture the NR PDCCH DM-RS. Within one PRB, NR PDCCH DM-RS is transmitted through subcarriers (#1, #5, #9). However, as shown in Figures (a) and (b) above, collision between DM-RS transmission and LTE CRS transmission may occur in one symbol or two symbols depending on the number of LTE CRS ports. At this time, it can be defined that NR PDCCH DM-RS transmission is not performed for REs where LTE CRS transmission is performed, that is, DM-RS transmission is punctured. For example, if a collision occurs with LTE CRS transmission on subcarrier #1, NR PDCCH DM-RS can be defined to be transmitted only through subcarrier (#5, #9).

In this case, as with frequency shifting in method 1 above, when setting CORESET, the base station tells the terminal to apply frequency shifting (i.e., subcarrier shifting) to the NR PDCCH DM-RS above. When setting a random CORESET, LTE CRS transmission is performed. It can be defined to newly include frequency information (e.g. carrierFreqDL information, carrierBandwidthDL information, etc.), LTE CRS antenna port number information (i.e., nrofCRS-Ports information), and vshift information. Based on this, any NR terminal obtains information on REs where LTE CRS transmission occurs, and when LTE CRS transmission is expected in any NR PDCCH DM-RS RE(s), DM-RS transmission from that RE(s) You can do puncturing. Alternatively, a punctured DM-RS pattern can be defined to indicate it directly through higher layer signaling. For example, you can define a punctured DM-RS pattern for subcarrier #1 or a punctured DM-RS for subcarrier #5 and subcarrier #9, respectively, so that information about this is signaled directly to the terminal.

Additionally, the base station can directly set/instruct or implicitly set the method to be applied among the above methods (frequency or time domain shifting or puncturing). For example, the base station can define the method to be applied among the above methods to signal to the terminal. That is, cell-specific or UE-specific CORESET configuration information can be defined to include a PDCCH candidate configured through the corresponding CORESET and DM-RS transmission configuration information for the PDCCH transmitted through it. Alternatively, the above NR PDCCH DM-RS shifting or puncturing can be implicitly defined to be applied according to the density of DM-RS. In other words, it can be defined to decide whether to apply puncturing or shifting according to the number of symbols (1 symbol or 2 symbols) in which collision with LTE CRS occurs and the duration of CORESET. Alternatively, the corresponding PDCCH DM-RS transmission method can be defined to be derived depending on the presence or absence of symbols that do not include LTE CRS or the ratio of symbols that include LTE CRS to the total CORESET duration. In other words, the method to be applied among the frequency domain shifting, time domain shifting, or puncturing methods can be defined to be mapped for each of the above collision cases. However, the relevant NR PDCCH DM-RS transmission method setting/instruction information is described from the base station's perspective, and when this is defined from the terminal's perspective, the NR PDCCH DM-RS reception method setting/instruction information or the channel estimation method for the NR PDCCH accordingly It can be defined as a setting/instruction information area. However, in the case of punctured DM-RS in method 3, configuration/instruction information regarding whether to transmit the corresponding punctured DM-RS to the terminal may not be separately defined, and in this case, the base station transmits NR PDCCH DM- in the RE that overlaps with the LTE CRS. RS transmission is punctured, but the UE can follow the existing NR PDCCH channel estimation method or perform punctured DM-RS-based channel estimation.

For example, method 2, the time shifting method, and the puncturing method of method 3 can be applied, and when setting a random CORESET, the base station can be defined to transmit to the terminal including the corresponding setting information, or MAC CE for a random CORESET It can be defined to indicate the corresponding DM-RS transmission method through signaling. Alternatively, it can be defined to include setting information about the UE's channel estimation method according to the corresponding DM-RS transmission. That is, in the case of Scheme 2 above, channel estimation is set to be performed only for DM-RS REs of symbols that do not overlap with the symbol on which LTE CRS transmission is performed, or according to Scheme 3, including symbols on which all LTE CRS transmission is performed. All symbols can include information that configures channel estimation to be performed using existing DM-RS REs. Or only DM-RS REs of symbols that do not include LTE CRS transmission according to Scheme 2 above, depending on whether any CORESET or PDCCH transmission includes symbols for which LTE CRS transmission is not performed according to the implicit method above. It can be defined to determine whether to perform channel estimation based on or based on existing NR PDCCH DM-RS REs.

In addition, in the present invention, signaling by the base station to the terminal includes both explicit signaling to the terminal through higher layer signaling, MAC CE signaling, or L1 control signaling, or implicit signaling methods. Here, higher layer signaling refers to RRC signaling transmitted through PDSCH and includes UE-specific, cell-specific, or UE-group common RRC signaling. L1 control signaling is DCI (Downlink Control Information) transmitted through PDCCH and includes UE-specific DCI, UE-group common DCI, or cell-specific DCI. Implicit signaling may include all cases where the settings are determined depending on the settings of other information.

The methods provided in this specification may be applied independently or may be operated in combination in any form. In addition, in the case of new terms, the terms used in this specification are arbitrary names whose meanings are easy to understand, and this specification can be applied even when other terms with the same meaning are actually used.

<General devices to which this specification can be applied>

Below, the device to which this specification can be applied will be described.

Figure 4 shows a block diagram of a processor on which the disclosure of the present specification is implemented.

As can be seen with reference to Figure 4, the processor 1020 in which the disclosure of this specification is implemented implements the proposed functions, procedures and/or methods described in this specification. Includes multiple circuits to do this: can do. For example, the processor 1020 may include a first circuit 1020-1, a second circuit 1020-2, and a third circuit 1020-3.

Additionally, although not shown, the processor 1020 may include more circuitry. Each circuit may include a plurality of transistors.

The processor 1020 may be called an application-specific integrated circuit (ASIC) or an application processor (AP), and includes at least one of a digital signal processor (DSP), a central processing unit (CPU), and a graphics processing unit (GPU). can do.

Figure 5 shows a wireless communication device according to an embodiment of the present specification.

Referring to Figure 5, the wireless communication system may include a first device 100a and a second device 100b.

The first device 100a includes a base station, a network node, a transmission terminal, a reception terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, and a connected car ( Connected Car), Drone (Unmanned Aerial Vehicle, UAV), AI (Artificial Intelligence) module, robot, AR (Augmented Reality) device, VR (Virtual Reality) device, MR (Mixed Reality) device, hologram device, public safety device, MTC device, IoT device, medical device, pin. It may be a tech device (or financial device), a security device, a climate/environment device, a device related to 5G services, or a device related to the 4th industrial revolution field other than that.

The second device (100b) includes a base station, a network node, a transmission terminal, a reception terminal, a wireless device, a wireless communication device, a vehicle, a vehicle equipped with an autonomous driving function, and a connected car ( Connected Car), Drone (Unmanned Aerial Vehicle, UAV), AI (Artificial Intelligence) module, robot, AR (Augmented Reality) device, VR (Virtual Reality) device, MR (Mixed Reality) device, hologram device, public safety device, MTC device, IoT device, medical device, pin. It may be a tech device (or financial device), a security device, a climate/environment device, a device related to 5G services, or a device related to the 4th industrial revolution field other than that.

The first device 100a includes at least one processor such as the processor 1020a, at least one memory such as the memory 1010a, and the transceiver 1031a. It may include at least one transceiver. The processor 1020a may perform the above-described functions, procedures, and/or methods. The processor 1020a is capable of performing one or more protocols. For example, the processor 1020a may perform one or more layers of a wireless interface protocol. The memory 1010a is connected to the processor 1020a and can store information and/or instructions in various forms. The transceiver 1031a is connected to the processor 1020a and can be controlled to transmit and receive wireless signals.

The second device 100b includes at least one processor such as the processor 1020b, at least one memory device such as the memory 1010b, and a transceiver 1031b. It may include at least one transceiver. The processor 1020b may perform the above-described functions, procedures, and/or methods. The processor 1020b may implement one or more protocols. For example, the processor 1020b may implement one or more layers of a wireless interface protocol. The memory 1010b is connected to the processor 1020b and can store information and/or instructions in various forms. The transceiver (1031b) is connected to the processor (1020b) and can be controlled to transmit and receive wireless signals.

The memory 1010a and/or the memory 1010b may be connected respectively inside or outside the processor 1020a and/or the processor 1020b. other processors through various technologies, such as wired or wireless connections. It may be connected to.

The first device 100a and/or the second device 100b may have one or more antennas. For example, antenna 1036a and/or antenna 1036b may be configured to transmit and receive wireless signals.

Figure 6 illustrates a block diagram of a network node according to an embodiment of the present specification.

In particular, FIG. 6 is a diagram illustrating the network nodes of FIG. 6 in more detail when the base station is divided into a central unit (CU) and a distributed unit (DU).

Referring to FIG. 6, base stations W20 and W30 may be connected to the core network W10, and base station W30 may be connected to a neighboring base station W20. For example, the interface between the base stations (W20, W30) and the core network (W10) may be referred to as NG, and the interface between the base station (W30) and the neighboring base station (W20) may be referred to as Xn.

The base station (W30) can be divided into CU (W32) and DU (W34, W36). That is, the base station W30 can be operated hierarchically separated. The CU (W32) may be connected to one or more DUs (W34, W36). For example, the interface between the CU (W32) and the DUs (W34, W36) may be referred to as F1.

The CU (W32) can perform the functions of the upper layers of the base station, and the DUs (W34, W36) can perform the functions of the lower layers of the base station. For example, the CU (W32) is a logical node that hosts the radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) layers of a base station (e.g., gNB). may be, and the DUs (W34, W36) may be logical nodes that host the radio link control (RLC), media access control (MAC), and physical (PHY) layers of the base station. Alternatively, CU (W32) may be a logical node hosting the RRC and PDCP layers of a base station (eg, en-gNB).

The operation of DUs (W34, W36) may be partially controlled by CU (W32). One DU (W34, W36) can support one or more cells. One cell can be supported by only one DU (W34, W36). One DU (W34, W36) can be connected to one CU (W32), and by appropriate implementation, one DU (W34, W36) can be connected to multiple CUs.

Figure 7 illustrates a block diagram of a communication device according to an embodiment of the present specification.

In particular, Figure 7 is a diagram illustrating the terminal of Figure 6 in more detail.

The terminal includes a memory 1010, a processor 1020, a transceiver 1031, a power management module 1091, a battery 1092, a display 1041, an input unit 1053, a speaker 1042, and a microphone 1052, Includes a subscriber identification module (SIM) card and one or more antennas.

Processor 1020 may be configured to implement the suggested functions, procedures and/or methods described herein. Layers of the air interface protocol may be implemented in processor 1020. Processor 1020 may include an application-specific integrated circuit (ASIC), other chipset, logic circuit, and/or data processing device. The processor 1020 may be an application processor (AP). The processor 1020 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator and demodulator). Examples of processors 1020 include SNAPDRAGONTM series processors manufactured by Qualcomm®, EXYNOSTM series processors manufactured by Samsung®, A series processors manufactured by Apple®, HELIOTM series processors manufactured by MediaTek®, INTEL® It may be an ATOMTM series processor manufactured by or a corresponding next-generation processor.

The power management module 1091 manages power for the processor 1020 and/or the transceiver 1031. Battery 1092 supplies power to power management module 1091. The display 1041 outputs the results processed by the processor 1020. Input unit 1053 receives input to be used by processor 1020. The input unit 1053 may be displayed on the display 1041. A SIM card is an integrated circuit used to securely store an international mobile subscriber identity (IMSI) and its associated keys, which are used to identify and authenticate subscribers in mobile phone devices such as mobile phones and computers. You can also store contact information on many SIM cards.

The memory 1010 is operably coupled to the processor 1020 and stores various information for operating the processor 610. Memory 1010 may include read-only memory (ROM), random access memory (RAM), flash memory, memory cards, storage media, and/or other storage devices. When an embodiment is implemented as software, the techniques described herein may be implemented as modules (eg, procedures, functions, etc.) that perform the functions described herein. Modules may be stored in memory 1010 and executed by processor 1020. The memory 1010 may be implemented inside the processor 1020. Alternatively, the memory 1010 may be implemented external to the processor 1020 and may be communicatively connected to the processor 1020 through various means known in the art.

The transceiver 1031 is operably coupled to the processor 1020 and transmits and/or receives wireless signals. The transceiver unit 1031 includes a transmitter and a receiver. The transceiver 1031 may include a baseband circuit for processing radio frequency signals. The transceiver controls one or more antennas to transmit and/or receive wireless signals. The processor 1020 transmits command information to the transceiver 1031 to initiate communication, for example, to transmit a wireless signal constituting voice communication data. The antenna functions to transmit and receive wireless signals. When receiving a wireless signal, the transceiver 1031 may transfer the signal and convert the signal to baseband for processing by the processor 1020. The processed signal may be converted into audible or readable information output through the speaker 1042.

The speaker 1042 outputs sound-related results processed by the processor 1020. Microphone 1052 receives sound-related input to be used by processor 1020.

The user inputs command information such as a phone number, for example, by pressing (or touching) a button on the input unit 1053 or by voice activation using the microphone 1052.

The processor 1020 receives this command information and processes it to perform appropriate functions, such as calling a phone number. Operational data can be extracted from the SIM card or memory 1010.

Additionally, the processor 1020 may display command information or driving information on the display 1041 for the user's recognition and convenience.

The examples of the present disclosure posted in the specification and drawings are merely provided as specific examples to easily explain the technical content of the present disclosure and aid understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In addition to the examples posted here, it is obvious to those skilled in the art that other modifications based on the technical idea of the invention can be implemented.

Claims (4)

In a terminal method for monitoring a control channel,
Receiving cell-specific reference signal (CRS) configuration information through signaling from a base station; and
Based on the received CRS setting information,
i) determining rate matching for at least one resource element (RE) of a physical downlink control channel (PDCCH),
ii) determining shifting of the demodulation reference signal (DM-RS) of the PDCCH;
iii) a method comprising at least one of the steps of determining puncturing of the DM-RS of the PDCCH. According to clause 1,
A method characterized in that the shifting of the DM-RS of the PDCCH is in the time domain. According to clause 1,
A method characterized in that the shifting of the DM-RS of the PDCCH is in the frequency domain. According to clause 1,
A method characterized in that the signaling is RRC (radio resource control) signaling.

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