JP7379495B2 - Terminals, wireless communication methods, base stations and systems - Google Patents

Description

The present disclosure relates to a terminal , a wireless communication method , a base station, and a system in a next-generation mobile communication system.

In Universal Mobile Telecommunications System (UMTS) networks, Long Term Evolution (LTE) has been specified for the purpose of higher data rates, lower delays, etc. (Non-Patent Document 1). Furthermore, LTE-Advanced (3GPP Rel. 10-14) has been specified for the purpose of further increasing capacity and sophistication of LTE (Third Generation Partnership Project (3GPP) Release (Rel.) 8, 9).

Successor systems to LTE (for example, also referred to as 5th generation mobile communication system (5G), 5G+ (plus), New Radio (NR), 3GPP Rel. 15 or later) are also being considered.

3GPP TS 36.300 V8.12.0 “Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2 (Release 8)”, April 2010

In future wireless communication systems (eg NR) beam management techniques are being introduced. For example, in NR, forming (or using) a beam at at least one of a base station and a user terminal (user terminal, user equipment (UE)) is being considered.

Beams can be broadly classified into digital beams (digital precoding) that can form a plurality of beams at the same time, and analog beams (analog precoding) that can form up to one beam at the same time.

In future wireless communication systems (for example, NR after Rel. 17), even at high frequencies, operation using only digital beams (which may be called full digital operation) without using analog beams will be used. It is assumed that operations that predominantly use digital beams will be used.

Even if base stations become fully digital, Rel. As long as there are 15 UEs, Rel. 15 UEs should be accommodated (supported).

However, in base stations (cells, networks) that support full digital, Rel. 15 UEs and UEs of later releases (for example, Rel. 16 UEs, Rel. 17 UEs, etc.) have not yet been considered. If UEs of different releases cannot communicate appropriately, there is a possibility that increase in communication throughput may be suppressed.

Therefore, one of the objects of the present disclosure is to provide a terminal , a wireless communication method , a base station, and a system that can appropriately communicate with each other even when terminals of different releases exist.

A terminal according to an aspect of the present disclosure provides a first demodulation reference signal that is transmitted to another terminal among the plurality of terminals when there are a plurality of terminals with different numbers of ports that can be set for demodulation reference signals. a control unit that assumes that different code division multiplexing (CDM) groups are applied to a reference signal and a second demodulation reference signal transmitted to its own terminal among the plurality of terminals ; It is characterized by comprising a receiving unit that receives the second demodulation reference signal at a port of a different CDM group from a port assigned to the first demodulation reference signal transmitted to the other terminal.

According to one aspect of the present disclosure, it is possible to provide a terminal , a wireless communication method , a base station, and a system that can appropriately communicate with each other even when terminals of different releases exist.

1A and 1B are diagrams illustrating an example of a transmitting and receiving configuration in which beam management is utilized. FIG. 2 is a diagram showing predictions of the progress of MIMO technology. 3A and 3B are diagrams illustrating an example of beam operation. FIG. 4 is a diagram illustrating an example in which the same DMRS port is configured between UEs with different releases. FIG. 5 is a diagram illustrating an example in which different DMRS ports are configured between UEs with different releases. FIG. 6 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. FIG. 7 is a diagram illustrating an example of the configuration of a base station according to an embodiment. FIG. 8 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. FIG. 9 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment.

(beam management)
In NR, a beam management technique has been introduced. For example, in NR, forming (or utilizing) beams in at least one of the base station and the UE is being considered.

By applying beam forming (Beam Forming (BF)), it is expected to reduce the difficulty of ensuring coverage due to an increase in carrier frequency and reduce radio wave propagation loss.

BF is a technology that forms a beam (antenna directivity) by controlling (also called precoding) the amplitude/phase of a signal transmitted or received from each element using, for example, a multi-element antenna. . Note that multiple input multiple output (MIMO) using such a multi-element antenna is also called massive MIMO.

1A and 1B are diagrams illustrating an example of a transmitting and receiving configuration in which beam management is utilized. In this example, the transmitting (Tx) side can form four beams (transmitting beams #1-#4), and the receiving (Rx) side can form two beams (receiving beams #1-#2). Assume a system in which this is possible.

In such a system, as shown in FIG. 1A, it is preferable to perform beam sweeping on both the transmitting and receiving sides, and to select an appropriate pair from a total of eight possible patterns of transmitting and receiving beam pairs shown in FIG. 1B. .

A pair of transmit and receive beams may be referred to as a beam pair; for example, transmit beam #3 and receive beam #2 as shown in FIG. 1A may be identified as beam pair candidate index = 6 in FIG. 1B.

Note that in beam management, instead of using a single beam, multiple levels of beam control such as a rough beam and a fine beam may be performed.

BF can be classified into digital BF and analog BF. Digital BF and analog BF may be called digital precoding and analog precoding, respectively.

Digital BF is, for example, a method of performing precoding signal processing (on digital signals) on baseband. In this case, parallel processing such as Inverse Fast Fourier Transform (IFFT), Digital to Analog Converter (DAC), Radio Frequency (RF), etc. chain)) are required. On the other hand, a number of beams can be formed at any timing according to the number of RF chains.

Analog BF is, for example, a method that uses a phase shifter on RF. Analog BF cannot form multiple beams at the same timing, but since it only rotates the phase of the RF signal, it can be easily configured and realized at low cost.

Note that a hybrid BF configuration in which a digital BF and an analog BF are combined is also realizable. The introduction of large-scale MIMO is being considered in NR, but if a huge number of beams are to be formed using only digital BF, the circuit configuration will become expensive, so the use of a hybrid BF configuration is also envisaged.

(TCI, spatial relations, QCL)
In NR, based on the transmission configuration indication state (TCI state), at least one of a signal and a channel (may also be expressed as signal/channel. Hereinafter, "A/B" will be similarly referred to as " reception processing (e.g., at least one of reception, demapping, demodulation, and decoding); transmission processing (e.g., transmission, mapping, precoding, modulation, and encoding); Controlling at least one of the following is currently being considered.

The TCI states may represent those that apply to downlink signals/channels. The equivalent of the TCI state applied to uplink signals/channels may be expressed as a spatial relation.

The TCI state is information regarding quasi-co-location (QCL) of signals/channels, and may also be called spatial reception parameters, spatial relation information (SRI), or the like. The TCI state may be set in the UE on a per-channel or per-signal basis.

QCL is a measure of the statistical properties of a signal/channel. For example, when one signal/channel and another signal/channel have a QCL relationship, the Doppler shift, Doppler spread, and average delay are calculated between these different signals/channels. ), delay spread, and spatial parameters (e.g., spatial Rx parameters) can be assumed to be the same (QCL with respect to at least one of these). You may.

Note that the spatial reception parameters may correspond to the UE's receive beam (eg, receive analog beam), and the beam may be identified based on the spatial QCL. QCL (or at least one element of QCL) in this disclosure may be read as sQCL (spatial QCL).

A plurality of types (QCL types) may be defined for QCL. For example, four QCL types A-D may be provided with different parameters (or parameter sets) that can be assumed to be the same, and the parameters (which may be referred to as QCL parameters) are shown below:
・QCL type A: Doppler shift, Doppler spread, average delay and delay spread,
・QCL type B: Doppler shift and Doppler spread,
・QCL type C: Doppler shift and average delay,
-QCL type D: Spatial reception parameters.

Types A to C may correspond to QCL information related to at least one of time and frequency synchronization processing, and type D may correspond to QCL information related to beam control.

It is not possible for the UE to assume that a given Control Resource Set (CORESET), channel or reference signal is in a particular QCL (e.g. QCL type D) relationship with another CORESET, channel or reference signal. , may also be called the QCL assumption.

The UE may determine at least one of a transmit beam (Tx beam) and a receive beam (Rx beam) for the signal/channel based on TCI conditions or QCL assumptions for the signal/channel.

The TCI state includes, for example, a target channel (or a reference signal (RS) for the channel) and another signal (for example, another downlink reference signal (DL-RS)). It may also be information regarding QCL with. The TCI state may be set (indicated) by upper layer signaling, physical layer signaling, or a combination thereof. The channel/signal of interest may be referred to as a target channel/RS (target channel/RS), simply a target, etc., and the other signal may be referred to as a reference RS (reference RS), simply a reference, etc. .

In the present disclosure, the upper layer signaling may be, for example, Radio Resource Control (RRC) signaling, Medium Access Control (MAC) signaling, broadcast information, etc., or a combination thereof.

The MAC signaling may use, for example, a MAC Control Element (MAC CE), a MAC Protocol Data Unit (PDU), or the like. Broadcast information includes, for example, Master Information Block (MIB), System Information Block (SIB), Remaining Minimum System Information (RMSI), and other system information ( Other System Information (OSI)) may also be used.

The physical layer signaling may be, for example, downlink control information (DCI).

Examples of channels on which the TCI state is set (designated) include the Physical Downlink Shared Channel (PDSCH), the Physical Downlink Control Channel (PDCCH), and the Physical Uplink Shared Channel (PUSCH). )), uplink control channel (Physical Uplink Control Channel (PUCCH)).

In addition, the RS (DL-RS) that has a QCL relationship with the channel is, for example, a synchronization signal block (SSB), a channel state information reference signal (CSI-RS), a measurement It may be at least one of a sounding reference signal (SRS). Alternatively, the DL-RS may be a CSI-RS (also referred to as Tracking Reference Signal (TRS)) used for tracking, or a reference signal (also referred to as QRS) used for QCL detection.

The SSB is a signal block that includes at least one of a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a broadcast channel (Physical Broadcast Channel (PBCH)). SSB may be called SS/PBCH block.

The TCI state information element ("TCI-state IE" of RRC) set by upper layer signaling may include one or more QCL information ("QCL-Info"). The QCL information may include at least one of information regarding DL-RSs having a QCL relationship (DL-RS relationship information) and information indicating a QCL type (QCL type information). The DL-RS related information includes the index of the DL-RS (for example, SSB index, Non-Zero-Power (NZP) CSI-RS resource ID (Identifier)), and the index of the cell where the RS is located. , the index of the Bandwidth Part (BWP) where the RS is located.

(Progress of MIMO technology and beam)
By the way, MIMO technology has been used in a frequency band (or frequency band) lower than 6 GHz, but application to a frequency band higher than 6 GHz is being considered in the future.

Note that a frequency band lower than 6 GHz may be called sub-6, frequency range (FR) 1, or the like. Frequency bands higher than 6 GHz may be referred to as above-6, FR2, millimeter wave (mmW), FR4, etc.

FIG. 2 is a diagram showing predictions of the progress of MIMO technology. Figure 2 shows an example of how many MIMO layers can be realized at each frequency in each era (for example, 2020, 2030, and 2040s), with frequency on the horizontal axis and the number of MIMO layers on the vertical axis. ing. The maximum number of MIMO layers is assumed to be limited by antenna size.

For example, looking at the line for the 2020s, it can be seen that the number of layers is greatest in a frequency band around sub-6 GHz, and the number of layers is quite small in a high frequency band such as 28 GHz. Furthermore, there is an applicable boundary for digital precoding and analog precoding in the middle of these frequency bands. In this generation, sub-6 GHz communication can be achieved using digital precoding, but it is assumed that communication at about 28 GHz will not be possible. Note that analog precoding may be applicable regardless of frequency band.

Around the 2030s, the number of MIMO layers will increase overall by adopting advanced technologies such as nonlinear precoding, and it is expected that precoding will become applicable even in higher frequency bands. Ru. Therefore, it is expected that the line for the 2030s will be a line that looks like the line for the 2020s expanded toward the upper right of the drawing.

The line for the 2040s is expected to be a line that is a further enlargement of the line for the 2030s toward the upper right of the drawing. In this era, it is expected that sub-6GHz communication can be realized using digital precoding even in frequency bands higher than 28GHz. It is assumed that the application boundaries of digital precoding will shift to significantly higher frequency bands from the 2020s.

Even with mmW, by using high-order MIMO and cooperating with multiple UEs, the degree of freedom and diversity of MIMO multiplexing is improved, and it is expected that throughput will be improved.

In this way, in future wireless communication systems (for example, NR after Rel. It is envisaged that an operation that uses digital beams predominantly will be used.

For example, in the case of full digital operation, improvement in frequency usage efficiency can be expected by applying orthogonal precoding (or orthogonal beams, digital beams) to multiple UEs at the same time. If digital beams cannot be applied appropriately, interference between UEs will increase, leading to deterioration in communication quality (or reduction in cell capacity). Note that orthogonal in the present disclosure may be read as quasi-orthogonal.

3A and 3B are diagrams illustrating an example of beam operation. In this example, FR2 is assumed, but the frequency range of the present disclosure is not limited to this. FIG. 3A shows Rel. FIG. 3B shows the operation of an analog beam such as that used in Rel. This shows the operation of digital beams as used in 17 and later.

In FIG. 3A, the base station (which may also be referred to as Transmission/Reception Point (TRP), panel, etc.) can only transmit one beam (beam #2 in FIG. 3A) at a given time. For this reason, the base station switches beams for transmission and reception to the UE.

In FIG. 3B, the base station can transmit multiple beams (beams #1-#4 in FIG. 3B) at a given time. Therefore, the base station can simultaneously transmit and receive data to and from multiple UEs using different beams.

(Reference signal port)
For orthogonalization of the MIMO layer, reference signals of multiple ports (eg, demodulation reference signal (DMRS), CSI-RS) are used.

For example, for Single User MIMO (SU-MIMO), different DMRS ports/CSI-RS ports may be configured for each layer. Regarding Multi User MIMO (MU-MIMO), different DMRS ports/CSI-RS ports may be configured for each layer within one UE and for each UE.

Note that if the number of CSI-RS ports is larger than the number of layers used for data, it is possible to measure the channel state more accurately based on the CSI-RS, which is expected to contribute to improving throughput.

In Rel-15 NR, multi-port DMRS uses Frequency Division Multiplexing (FDM), Frequency Domain Orthogonal Cover Code (FD-OCC), and Time Domain OCC ( By using TD-OCC), etc., a maximum of 8 ports for type 1 DMRS (DMRS configuration type 1) and a maximum of 12 ports for type 2 DMRS (DMRS configuration type 2) are supported.

Rel. In the X.15 NR, a comb-shaped transmission frequency pattern (comb-shaped resource set) is used as the FDM. Cyclic shift (CS) is used as the FD-OCC. Further, the above TD-OCC may be applied only to double symbol DMRS.

Also, Rel. In V.15 NR, a maximum of 32 ports of CSI-RS are supported by using FDM, time division multiplexing (TDM), frequency domain OCC, time domain OCC, etc. The same method as the above-mentioned DMRS may be applied to orthogonalize the CSI-RS.

A group of DMRS ports (or CSI-RS ports) that are orthogonalized by FD-OCC/TD-OCC as described above is also called a Code Division Multiplexing (CDM) group.

Now, even if base stations become fully digital, Rel. As long as there are 15 UEs, Rel. 15 UEs should be accommodated (supported).

However, in base stations (cells, networks) that support full digital, Rel. 15 UEs and UEs of later releases (for example, Rel. 16 UEs, Rel. 17 UEs, etc.) have not yet been considered. For example, in FIG. 3B, UE1 is Rel. 15 UE, and UE2 is Rel. 17 UE, it is not clear in the current standards what kind of assumptions each UE will perform processing based on.

For example, without clarity on how to allocate DMRS ports to UEs of different releases, UEs of different releases cannot communicate properly. If UEs of different releases cannot communicate appropriately, there is a possibility that increase in communication throughput may be suppressed.

Therefore, the present inventors came up with a method for appropriately processing communication even when there are terminals with different releases.

Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the drawings. The wireless communication methods according to each embodiment may be applied singly or in combination.

Note that "release" in the present disclosure may mean release of the 3GPP standard.

Hereinafter, in this disclosure, "old release UE" refers to Rel. 15 NR UE, and a "new release UE" means a Rel. Although the description will be made assuming that it means a UE of NR 15 or later (for example, a UE of Rel. 16, a UE of Rel. 17), the present invention is not limited to this.

For example, an "older release UE" is defined as a maximum or configurable port number for a particular reference signal (e.g., CSI-RS port number, SRS port number, at least one of PUSCH, PDSCH, PDCCH and PUCCH). DMRS port number) may be less than or equal to a predetermined number, and a "new release UE" means a UE with a greater number of ports for the specific reference signal than the "old release UE". You may. A "new release UE" may mean a UE with different capabilities than an "old release UE."

Moreover, when simply written as "UE", the "UE" may be read as at least one of "old release UE" and "new release UE".

Hereinafter, "RS" in the present disclosure will be explained assuming "DMRS", but is not limited to this. “RS” in the present disclosure may be read as at least one of “DMRS,” “CSI-RS,” “SSB,” and “Cell-specific Reference Signal (CRS).” . Further, the TCI state of the RS (RS indicated by the TCI state) will be described assuming the TCI state of "DMRS" (DMRS indicated by the TCI state), but is not limited to this. The TCI state of the RS of the present disclosure includes the TCI state of "DMRS", the TCI state of "CSI-RS" (CSI-RS indicated by the TCI state), the TCI state of "SSB" (SSB indicated by the TCI state), and the TCI state of "CSI-RS". CRS" TCI status (CRS indicated by the TCI status).

(Wireless communication method)
The present inventors studied the above-mentioned CDM group. Since at least FDM is performed between different CDM groups, orthogonality is ensured. On the other hand, within the same CDM group, the orthogonality of the applied OCC may collapse due to channel fluctuations or the like. In this case, we focused on the fact that if channels/signals within the same CDM group are received with different reception powers, a near-far problem may occur and orthogonality may not be guaranteed.

Therefore, the present inventors came up with the idea of orthogonalizing channels/signals of different layers within one UE using OCC in the same CDM group, while adapting different CDM groups to channels/signals between different UEs. did. According to this configuration, UE's DMRS, CSI-RS, etc. can be efficiently multiplexed.

In addition, the present inventors have found that it is preferable to configure RSs of different CDM groups between UEs in MU-MIMO, which is orthogonalized using digital precoding, because it is difficult to ensure orthogonality with digital precoding. I discovered that. On the other hand, it has been found that even when digital precoding is used, RSs in the same CDM group may be set if orthogonality can be ensured. Based on these findings, the present inventors came up with an idea about the RS beam assumption and the RS port assumption.

RS beams, ports, etc. that can be assumed for UEs of different releases will be explained using FIGS. 4 and 5. FIG. 4 is a diagram illustrating an example in which the same DMRS port is configured between UEs with different releases. FIG. 5 is a diagram illustrating an example in which different DMRS ports are configured between UEs with different releases. Note that "port" in the present disclosure may be interchanged with "resource."

It is assumed that UE1 is an old release UE (eg, Rel.15 UE). It is assumed that UE2 is a new release UE (eg, Rel.17 UE). It is also assumed that the base station supports a new release (eg, Rel. 17). Note that in the present disclosure, UE1 may be replaced with UE2, and UE2 may be replaced with UE1. That is, although the following description mainly describes the UE1, each operation may be reread with the UE2 as the main character.

Note that in both the examples in FIGS. 4 and 5, the RS beam (beam #1) is transmitted to the own UE (UE1), and the RS beam (beam #2) is transmitted to the other UE (UE2). and may each be transmitted using an analog beam, a digital beam, or a combination thereof.

UE1 may make a predetermined assumption as the QCL relationship between the RS transmitted to its own UE (UE1) and the RS transmitted to another UE (UE2). Then, the UE 1 may perform the RS reception process based on predetermined assumptions. The UE 1 may, for example, make the following assumption (1-1) or (1-2) as the predetermined assumption.

Note that in this disclosure, an RS transmitted to a certain UE may be replaced with an RS (if any) that corresponds to a predetermined QCL type (for example, QCL type D) of the TCI state set to the UE. Alternatively, it may be read as an RS that has a relationship between a predetermined channel/signal and a predetermined QCL type (for example, QCL type D). Hereinafter, QCL type D may be interchanged with a predetermined QCL type.

(1-1) UE1 assumes that the QCL relationship between the RS transmitted to its own UE (UE1) and the RS transmitted to another UE (UE2) is not QCL type D. In other words, UE1 assumes that the RS transmitted to its own UE (UE1) is RS#1, and the RS transmitted to the other UE (UE2) is RS#2, which is not QCL-D. You can assume that. In this case, UE1 may assume that the beams of these RSs are orthogonalized using analog precoding. Note that UE1 may assume that the beams of these RSs are orthogonalized using both analog precoding and digital precoding.

(1-2) UE1 assumes that the QCL relationship between the RS transmitted to its own UE (UE1) and the RS transmitted to another UE (UE2) is QCL type D. In other words, UE1 assumes that the RS transmitted to its own UE (UE1) is RS#1, and the RS transmitted to other UE (UE2) is RS#1 and QCL-D RS (that is, RS#1). ) may be assumed. In this case, UE1 may assume that the beams of these RSs are orthogonalized with digital precoding. Note that UE1 may assume that these RSs are transmitted using the same analog precoding (analog beam).

The UE 1 may perform at least one of the assumptions described in (1-1) or (1-2) above, and may also execute (2-1) or (2-2) below. Which of the following (2-1) and (2-2) to perform is determined based on the port used for the received RS (for example, based on the port index or based on the port resource). It's okay.

Note that an instruction (instruction information) about the port to be used may be transmitted from the base station, and the UE may use the port according to the instruction. The port in this disclosure is assumed to be a port used for DMRS (DMRS port), but may be a port used for at least one of DMRS, CSI-RS, TRS, and SRS, for example.

(2-1) UE1 performs reception processing of an RS transmitted to its own UE (UE1) using the same port assigned to an RS transmitted to another UE (UE2). For example, as shown in FIG. 4, it may be assumed that UE1 and UE2 use the same port (DMRS port #1). In this case, the antenna ports can be used efficiently within one beam (or one beam of QCL-D), and frequency usage efficiency can be improved.

(2-2) UE1 performs reception processing of the RS transmitted to its own UE (UE1) using a port different from the port assigned to the RS transmitted to another UE (UE2). For example, as shown in FIG. 5, it may be assumed that UE1 uses DMRS port #1 and UE2 uses DMRS port #2. In this case, even if the orthogonality between different beams (or multiple beams of QCL type D) is destroyed due to reflection scattering, etc., the orthogonality between the reference signal of the own UE and the reference signal of other UEs can be ensured, Communication quality can be improved.

In addition, when applying (2-1), if UE1 uses the same port for at least the same RE between UEs/beams (between QCL type D beams), UE1 will It may be assumed that the RS transmitted to other UEs has a different reference signal sequence (a different reference signal sequence is set). For example, the UE 1 may assume that different scramble IDs are set for the RS transmitted to its own UE and the RS transmitted to other UEs, or the beam index is used for reference signal sequence generation/hopping. may be assumed to be used. Here, the beam index may be, for example, at least one of an SSB index, a CSI-RS index, etc. used for beam identification.

In this way, by using different reference signal sequences between RSs of the same port, their orthogonality can be increased. Note that different ports may be used for the same RE between UEs/beams.

QCL type D in the present disclosure may mean, for example, the following (3-1) or (3-2).
(3-1) The target and reference analog beams are equal.
(3-2) The target and reference beams/precoders (beams/precoders including analog and digital) are equal.

When using MU-MIMO in a digital precoder and applying the above (3-2), (1-1) of the above (1-1) and (1-2) may be applied. That is, UE1 assumes that the QCL relationship between the RS transmitted to its own UE (UE1) and the RS transmitted to another UE (UE2) is not QCL type D. A UE that assumes (3-2) above assumes that, regardless of whether the precoder used is digital or analog, if multiple beams have different directions, different QCL type D RSs will be assigned to them. Good too.

Regarding the setting of the TCI state, the UE may assume that in the case of full digital operation, an RS of QCL type D (QCL type D in (3-2) above) is set in the TCI state. In this case, the UE may assume that one panel can transmit and receive only one QCL-D RS at the same time.

Regarding the setting of the TCI state, the UE may assume that in the case of full digital operation, an RS of QCL type D (QCL type D in (3-1) above) is not set in the TCI state. In this case, the UE may assume that QCL type D is used only for analog beam selection and cannot be used for digital beam selection.

Note that in MU-MIMO in which the UE is orthogonalized by digital precoding, it may be assumed that DMRS of different CDM groups (at least different DMRS ports) are configured between the UEs. Further, depending on the implementation of the base station, processing equivalent to MU-MIMO may be performed on the analog beam. As long as beam orthogonality is ensured, the UE may transmit and receive data using the same DMRS port used by other UEs.

Note that the QCL type D in (3-2) above may be referred to as QCL type E (QCL-E). E may be another alphanumeric character. The "precoder" in QCL-E may be replaced with a spatial reception parameter ("Spatial Rx parameter") or a spatial transmission parameter ("Spatial Tx parameter"). This spatial reception parameter is based on 3GPP Rel. In order to distinguish it from the spatial reception parameter of QCL-D in 15, it may be called, for example, spatial reception parameter 2 (Spatial Rx parameter II) or spatial transmission parameter 2 (Spatial Tx parameter II). QCL type D of the present disclosure may be replaced with QCL type E.

According to the embodiment described above, by performing reception processing based on a predetermined assumption about the QCL relationship between a signal transmitted to another terminal and a signal transmitted to the own terminal, different releases can be generated. Even if there are multiple terminals, each can communicate appropriately.

In addition, in the above-mentioned embodiment, although UE1 is a UE of an old release, and UE2 is a UE of a new release, although it was described assuming that it is a UE, it is not limited to this. For example, the embodiments described above are also applicable if both UE1 and UE2 are new release UEs.

Furthermore, in the embodiments described above, it may be assumed that both UE1 and UE2 connect to the same serving cell, or it may be assumed that UE1 and UE2 connect to different serving cells.

(wireless communication system)
The configuration of a wireless communication system according to an embodiment of the present disclosure will be described below. In this wireless communication system, communication is performed using any one of the wireless communication methods according to the above-described embodiments of the present disclosure or a combination thereof.

FIG. 6 is a diagram illustrating an example of a schematic configuration of a wireless communication system according to an embodiment. The wireless communication system 1 may be a system that realizes communication using Long Term Evolution (LTE), 5th generation mobile communication system New Radio (5G NR), etc. specified by the Third Generation Partnership Project (3GPP). .

Furthermore, the wireless communication system 1 may support dual connectivity between multiple Radio Access Technologies (RATs) (Multi-RAT Dual Connectivity (MR-DC)). MR-DC has dual connectivity between LTE (Evolved Universal Terrestrial Radio Access (E-UTRA)) and NR (E-UTRA-NR Dual Connectivity (EN-DC)), and dual connectivity between NR and LTE (NR-E -UTRA Dual Connectivity (NE-DC)).

In EN-DC, an LTE (E-UTRA) base station (eNB) is a master node (Master Node (MN)), and an NR base station (gNB) is a secondary node (Secondary Node (SN)). In NE-DC, the NR base station (gNB) is the MN, and the LTE (E-UTRA) base station (eNB) is the SN.

The wireless communication system 1 has dual connectivity between multiple base stations within the same RAT (for example, NR-NR Dual Connectivity (NN-DC) where both the MN and SN are NR base stations (gNB)). )) may be supported.

The wireless communication system 1 includes a base station 11 that forms a macro cell C1 with relatively wide coverage, and base stations 12 (12a-12c) that are located within the macro cell C1 and form a small cell C2 that is narrower than the macro cell C1. You may prepare. User terminal 20 may be located within at least one cell. The arrangement, number, etc. of each cell and user terminal 20 are not limited to the embodiment shown in the figure. Hereinafter, when base stations 11 and 12 are not distinguished, they will be collectively referred to as base station 10.

The user terminal 20 may be connected to at least one of the plurality of base stations 10. The user terminal 20 may utilize at least one of carrier aggregation (CA) using a plurality of component carriers (CC) and dual connectivity (DC).

Each CC may be included in at least one of a first frequency band (Frequency Range 1 (FR1)) and a second frequency band (Frequency Range 2 (FR2)). Macro cell C1 may be included in FR1, and small cell C2 may be included in FR2. For example, FR1 may be a frequency band below 6 GHz (sub-6 GHz), and FR2 may be a frequency band above 24 GHz (above-24 GHz). Note that the frequency bands and definitions of FR1 and FR2 are not limited to these, and FR1 may correspond to a higher frequency band than FR2, for example.

Further, the user terminal 20 may communicate using at least one of time division duplex (TDD) and frequency division duplex (FDD) in each CC.

The plurality of base stations 10 may be connected by wire (for example, optical fiber compliant with Common Public Radio Interface (CPRI), X2 interface, etc.) or wirelessly (for example, NR communication). For example, when NR communication is used as a backhaul between base stations 11 and 12, base station 11, which is an upper-level station, is an Integrated Access Backhaul (IAB) donor, and base station 12, which is a relay station, is an IAB donor. May also be called a node.

Base station 10 may be connected to core network 30 via other base stations 10 or directly. The core network 30 may include, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), a Next Generation Core (NGC), and the like.

The user terminal 20 may be a terminal compatible with at least one of communication systems such as LTE, LTE-A, and 5G.

In the wireless communication system 1, an orthogonal frequency division multiplexing (OFDM)-based wireless access method may be used. For example, in at least one of the downlink (DL) and uplink (UL), Cyclic Prefix OFDM (CP-OFDM), Discrete Fourier Transform Spread OFDM (DFT-s-OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), Single Carrier Frequency Division Multiple Access (SC-FDMA), etc. may be used.

A wireless access scheme may be referred to as a waveform. Note that in the wireless communication system 1, other wireless access methods (for example, other single carrier transmission methods, other multicarrier transmission methods) may be used as the UL and DL radio access methods.

In the wireless communication system 1, downlink channels include a physical downlink shared channel (PDSCH) shared by each user terminal 20, a broadcast channel (physical broadcast channel (PBCH)), and a downlink control channel (physical downlink control channel). Channel (PDCCH)) or the like may be used.

In the wireless communication system 1, uplink channels include an uplink shared channel (Physical Uplink Shared Channel (PUSCH)) shared by each user terminal 20, an uplink control channel (Physical Uplink Control Channel (PUCCH)), and a random access channel. (Physical Random Access Channel (PRACH)) or the like may be used.

User data, upper layer control information, System Information Block (SIB), etc. are transmitted through the PDSCH. User data, upper layer control information, etc. may be transmitted by PUSCH. Furthermore, a Master Information Block (MIB) may be transmitted via the PBCH.

Lower layer control information may be transmitted by PDCCH. The lower layer control information may include, for example, downlink control information (DCI) that includes scheduling information for at least one of PDSCH and PUSCH.

Note that the DCI that schedules PDSCH may be called DL assignment, DL DCI, etc., and the DCI that schedules PUSCH may be called UL grant, UL DCI, etc. Note that PDSCH may be replaced with DL data, and PUSCH may be replaced with UL data.

A control resource set (CORESET) and a search space may be used to detect the PDCCH. CORESET corresponds to a resource for searching DCI. The search space corresponds to a search area and a search method for PDCCH candidates. One CORESET may be associated with one or more search spaces. The UE may monitor the CORESET associated with a certain search space based on the search space configuration.

One search space may correspond to PDCCH candidates corresponding to one or more aggregation levels. One or more search spaces may be referred to as a search space set. Note that "search space", "search space set", "search space setting", "search space set setting", "CORESET", "CORESET setting", etc. in the present disclosure may be read interchangeably.

PUCCH allows channel state information (CSI), delivery confirmation information (for example, may be called Hybrid Automatic Repeat reQuest ACKnowledgement (HARQ-ACK), ACK/NACK, etc.), and scheduling request ( Uplink Control Information (UCI) including at least one of SR)) may be transmitted. A random access preamble for establishing a connection with a cell may be transmitted by PRACH.

Note that in the present disclosure, downlinks, uplinks, etc. may be expressed without adding "link". Furthermore, various channels may be expressed without adding "Physical" at the beginning.

In the wireless communication system 1, a synchronization signal (SS), a downlink reference signal (DL-RS), and the like may be transmitted. In the wireless communication system 1, the DL-RS includes a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS), and a demodulation reference signal (DeModulation). Reference Signal (DMRS)), Positioning Reference Signal (PRS), Phase Tracking Reference Signal (PTRS), etc. may be transmitted.

The synchronization signal may be, for example, at least one of a primary synchronization signal (PSS) and a secondary synchronization signal (SSS). A signal block including SS (PSS, SSS) and PBCH (and DMRS for PBCH) may be called an SS/PBCH block, SS Block (SSB), etc. Note that SS, SSB, etc. may also be called reference signals.

In addition, in the wireless communication system 1, measurement reference signals (Sounding Reference Signal (SRS)), demodulation reference signals (DMRS), etc. are transmitted as uplink reference signals (UL-RS). good. Note that DMRS may be called a user terminal-specific reference signal (UE-specific reference signal).

(base station)
FIG. 7 is a diagram illustrating an example of the configuration of a base station according to an embodiment. The base station 10 includes a control section 110, a transmitting/receiving section 120, a transmitting/receiving antenna 130, and a transmission line interface 140. Note that one or more of each of the control unit 110, the transmitting/receiving unit 120, the transmitting/receiving antenna 130, and the transmission path interface 140 may be provided.

Note that this example mainly shows functional blocks that are characteristic of the present embodiment, and it may be assumed that base station 10 also has other functional blocks necessary for wireless communication. A part of the processing of each unit described below may be omitted.

The control unit 110 controls the base station 10 as a whole. The control unit 110 can be configured from a controller, a control circuit, etc., which will be explained based on common recognition in the technical field related to the present disclosure.

The control unit 110 may control signal generation, scheduling (eg, resource allocation, mapping), and the like. The control unit 110 may control transmission and reception, measurement, etc. using the transmitting/receiving unit 120, the transmitting/receiving antenna 130, and the transmission path interface 140. The control unit 110 may generate data, control information, a sequence, etc. to be transmitted as a signal, and may transfer the generated data to the transmitting/receiving unit 120. The control unit 110 may perform communication channel call processing (setting, release, etc.), status management of the base station 10, radio resource management, and the like.

The transmitting/receiving section 120 may include a baseband section 121, a radio frequency (RF) section 122, and a measuring section 123. The baseband section 121 may include a transmission processing section 1211 and a reception processing section 1212. The transmitting/receiving unit 120 includes a transmitter/receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measuring circuit, a transmitting/receiving circuit, etc., which are explained based on common understanding in the technical field related to the present disclosure. be able to.

The transmitter/receiver 120 may be configured as an integrated transmitter/receiver, or may be configured from a transmitter and a receiver. The transmitting section may include a transmitting processing section 1211 and an RF section 122. The reception section may include a reception processing section 1212, an RF section 122, and a measurement section 123.

The transmitting/receiving antenna 130 can be configured from an antenna described based on common recognition in the technical field related to the present disclosure, such as an array antenna.

The transmitter/receiver 120 may transmit the above-mentioned downlink channel, synchronization signal, downlink reference signal, etc. The transmitter/receiver 120 may receive the above-mentioned uplink channel, uplink reference signal, and the like.

The transmitting/receiving unit 120 may form at least one of a transmitting beam and a receiving beam using digital beamforming (eg, precoding), analog beamforming (eg, phase rotation), or the like.

The transmitting/receiving unit 120 (transmission processing unit 1211) performs Packet Data Convergence Protocol (PDCP) layer processing, Radio Link Control (RLC) layer processing (for example, on the data, control information, etc. acquired from the control unit 110). RLC retransmission control), Medium Access Control (MAC) layer processing (for example, HARQ retransmission control), etc. may be performed to generate a bit string to be transmitted.

The transmitting/receiving unit 120 (transmission processing unit 1211) performs channel encoding (which may include error correction encoding), modulation, mapping, filter processing, and discrete Fourier transform (DFT) on the bit string to be transmitted. A baseband signal may be output after performing transmission processing such as processing (if necessary), Inverse Fast Fourier Transform (IFFT) processing, precoding, and digital-to-analog conversion.

The transmitting/receiving unit 120 (RF unit 122) may perform modulation, filter processing, amplification, etc. on the baseband signal in a radio frequency band, and may transmit the signal in the radio frequency band via the transmitting/receiving antenna 130. .

On the other hand, the transmitting/receiving section 120 (RF section 122) may perform amplification, filter processing, demodulation into a baseband signal, etc. on the radio frequency band signal received by the transmitting/receiving antenna 130.

The transmitting/receiving unit 120 (reception processing unit 1212) performs analog-to-digital conversion, fast Fourier transform (FFT) processing, and inverse discrete Fourier transform (IDFT) on the acquired baseband signal. )) processing (if necessary), applying reception processing such as filter processing, demapping, demodulation, decoding (which may include error correction decoding), MAC layer processing, RLC layer processing and PDCP layer processing, User data etc. may also be acquired.

The transmitting/receiving unit 120 (measuring unit 123) may perform measurements regarding the received signal. For example, the measurement unit 123 may perform Radio Resource Management (RRM) measurement, Channel State Information (CSI) measurement, etc. based on the received signal. The measurement unit 123 measures reception power (for example, Reference Signal Received Power (RSRP)), reception quality (for example, Reference Signal Received Quality (RSRQ), Signal to Interference plus Noise Ratio (SINR), Signal to Noise Ratio (SNR)). , signal strength (for example, Received Signal Strength Indicator (RSSI)), propagation path information (for example, CSI), etc. may be measured. The measurement results may be output to the control unit 110.

The transmission path interface 140 transmits and receives signals (backhaul signaling) between devices included in the core network 30, other base stations 10, etc., and transmits and receives user data (user plane data) for the user terminal 20, control plane It is also possible to acquire and transmit data.

Note that the transmitting unit and receiving unit of the base station 10 in the present disclosure may be configured by at least one of the transmitting/receiving unit 120, the transmitting/receiving antenna 130, and the transmission path interface 140.

Note that the control unit 110 may control signal processing so that the relationship between the signal transmitted to a specific UE and the signal transmitted to other UEs is a QCL relationship. The QCL relationship may be of QCL type D or may not be of QCL type D. The transmitting/receiving unit 120 may transmit the processed signal to the specific UE and the other UE.

The control unit 110 may assign different ports or the same port to a signal to be transmitted to a specific UE and a signal to be transmitted to another UE. The transmitting/receiving unit 120 may transmit an instruction indicating port assignment to the specific UE and the other UE.

(user terminal)
FIG. 8 is a diagram illustrating an example of the configuration of a user terminal according to an embodiment. The user terminal 20 includes a control section 210, a transmitting/receiving section 220, and a transmitting/receiving antenna 230. Note that one or more of each of the control unit 210, the transmitting/receiving unit 220, and the transmitting/receiving antenna 230 may be provided.

Note that this example mainly shows functional blocks that are characteristic of the present embodiment, and it may be assumed that the user terminal 20 also has other functional blocks necessary for wireless communication. A part of the processing of each unit described below may be omitted.

The control unit 210 controls the entire user terminal 20. The control unit 210 can be configured from a controller, a control circuit, etc., which will be explained based on common recognition in the technical field related to the present disclosure.

The control unit 210 may control signal generation, mapping, and the like. The control unit 210 may control transmission and reception using the transmitting/receiving unit 220 and the transmitting/receiving antenna 230, measurement, and the like. The control unit 210 may generate data, control information, sequences, etc. to be transmitted as a signal, and may transfer the generated data to the transmitting/receiving unit 220.

The transmitting/receiving section 220 may include a baseband section 221, an RF section 222, and a measuring section 223. The baseband section 221 may include a transmission processing section 2211 and a reception processing section 2212. The transmitting/receiving unit 220 can be configured from a transmitter/receiver, an RF circuit, a baseband circuit, a filter, a phase shifter, a measuring circuit, a transmitting/receiving circuit, etc., which are explained based on common recognition in the technical field related to the present disclosure.

The transmitting/receiving section 220 may be configured as an integrated transmitting/receiving section, or may be configured from a transmitting section and a receiving section. The transmitting section may include a transmitting processing section 2211 and an RF section 222. The reception section may include a reception processing section 2212, an RF section 222, and a measurement section 223.

The transmitting/receiving antenna 230 can be configured from an antenna described based on common recognition in the technical field related to the present disclosure, such as an array antenna.

The transmitter/receiver 220 may receive the above-described downlink channel, synchronization signal, downlink reference signal, and the like. The transmitter/receiver 220 may transmit the above-mentioned uplink channel, uplink reference signal, and the like.

The transmitting/receiving unit 220 may form at least one of a transmitting beam and a receiving beam using digital beamforming (eg, precoding), analog beamforming (eg, phase rotation), or the like.

The transmission/reception unit 220 (transmission processing unit 2211) performs PDCP layer processing, RLC layer processing (e.g. RLC retransmission control), MAC layer processing (e.g. , HARQ retransmission control), etc., to generate a bit string to be transmitted.

The transmitting/receiving unit 220 (transmission processing unit 2211) performs channel encoding (which may include error correction encoding), modulation, mapping, filter processing, DFT processing (as necessary), and IFFT processing on the bit string to be transmitted. , precoding, digital-to-analog conversion, etc., and output a baseband signal.

Note that whether or not to apply DFT processing may be based on the settings of transform precoding. When transform precoding is enabled for a certain channel (for example, PUSCH), the transmitting/receiving unit 220 (transmission processing unit 2211) performs the above processing in order to transmit the channel using the DFT-s-OFDM waveform. DFT processing may be performed as the transmission processing, or if not, DFT processing may not be performed as the transmission processing.

The transmitting/receiving unit 220 (RF unit 222) may perform modulation, filter processing, amplification, etc. on the baseband signal in a radio frequency band, and may transmit the signal in the radio frequency band via the transmitting/receiving antenna 230. .

On the other hand, the transmitting/receiving section 220 (RF section 222) may perform amplification, filter processing, demodulation into a baseband signal, etc. on the radio frequency band signal received by the transmitting/receiving antenna 230.

The transmission/reception unit 220 (reception processing unit 2212) performs analog-to-digital conversion, FFT processing, IDFT processing (if necessary), filter processing, demapping, demodulation, and decoding (error correction) on the acquired baseband signal. (which may include decoding), MAC layer processing, RLC layer processing, and PDCP layer processing may be applied to obtain user data and the like.

The transmitting/receiving section 220 (measuring section 223) may perform measurements regarding the received signal. For example, the measurement unit 223 may perform RRM measurement, CSI measurement, etc. based on the received signal. The measurement unit 223 may measure received power (for example, RSRP), reception quality (for example, RSRQ, SINR, SNR), signal strength (for example, RSSI), propagation path information (for example, CSI), and the like. The measurement results may be output to the control unit 210.

Note that the transmitting unit and receiving unit of the user terminal 20 in the present disclosure may be configured by at least one of the transmitting/receiving unit 220 and the transmitting/receiving antenna 230.

Note that the control unit 210 may make a predetermined assumption regarding the QCL relationship between the signal transmitted to another UE and the signal transmitted to the own UE. The control unit 210 may assume that the QCL relationship is QCL type D, or may assume that the QCL relationship is not QCL type D, as the predetermined assumption.

The transmitter/receiver 220 may perform the reception process based on a predetermined assumption made by the controller 210. The transmitting/receiving unit 220 may perform reception processing on signals transmitted to its own UE using the same port as the port assigned to signals transmitted to other UEs or a different port.

(Hardware configuration)
It should be noted that the block diagram used to explain the above embodiment shows blocks in functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Furthermore, the method for realizing each functional block is not particularly limited. That is, each functional block may be realized using one physically or logically coupled device, or may be realized using two or more physically or logically separated devices directly or indirectly (e.g. , wired, wireless, etc.) and may be realized using a plurality of these devices. The functional block may be realized by combining software with the one device or the plurality of devices.

Here, functions include judgment, decision, judgement, calculation, calculation, processing, derivation, investigation, exploration, confirmation, reception, transmission, output, access, solution, selection, selection, establishment, comparison, assumption, expectation, and consideration. , broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocating, mapping, assigning, etc. Not limited. For example, a functional block (configuration unit) that performs transmission may be called a transmitting unit, a transmitter, or the like. In either case, as described above, the implementation method is not particularly limited.

For example, a base station, a user terminal, etc. in an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. FIG. 9 is a diagram illustrating an example of the hardware configuration of a base station and a user terminal according to an embodiment. The base station 10 and user terminal 20 described above may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc. .

Note that in the present disclosure, words such as apparatus, circuit, device, section, unit, etc. can be read interchangeably. The hardware configuration of the base station 10 and the user terminal 20 may be configured to include one or more of each device 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. Also, the processing may be performed by one processor, or the processing may be performed by two or more processors simultaneously, sequentially, or using other techniques. Note that the processor 1001 may be implemented using one or more chips.

Each function in the base station 10 and the user terminal 20 is performed by, for example, loading predetermined software (program) onto hardware such as a processor 1001 and a memory 1002, so that the processor 1001 performs calculations and communicates via the communication device 1004. This is achieved by controlling at least one of reading and writing data in the memory 1002 and storage 1003.

The processor 1001, for example, operates an operating system to control the entire computer. The processor 1001 may be configured by a central processing unit (CPU) that includes interfaces with peripheral devices, a control device, an arithmetic device, registers, and the like. For example, at least a portion of the above-mentioned control unit 110 (210), transmitting/receiving unit 120 (220), etc. may be realized by the processor 1001.

Furthermore, the processor 1001 reads programs (program codes), software modules, data, and the like from at least one of the storage 1003 and the communication device 1004 to the memory 1002, and executes various processes in accordance with these. As the program, a program that causes a computer to execute at least part of the operations described in the above embodiments is used. For example, the control unit 110 (210) may be realized by a control program stored in the memory 1002 and operated in the processor 1001, and other functional blocks may also be realized in the same way.

Memory 1002 is a computer-readable storage medium, such as at least Read Only Memory (ROM), Erasable Programmable ROM (EPROM), Electrically EPROM (EEPROM), Random Access Memory (RAM), or other suitable storage medium. It may be composed of one. Memory 1002 may be called a register, cache, main memory, or the like. The memory 1002 can store executable programs (program codes), software modules, and the like to implement a wireless communication method according to an embodiment of the present disclosure.

The storage 1003 is a computer-readable recording medium, such as a flexible disk, a floppy (registered trademark) disk, a magneto-optical disk (for example, a compact disk (CD-ROM), etc.), a digital versatile disk, removable disk, hard disk drive, smart card, flash memory device (e.g., card, stick, key drive), magnetic stripe, database, server, or other suitable storage medium. It may be configured by Storage 1003 may also be called an auxiliary storage device.

The communication device 1004 is hardware (transmission/reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, a communication module, or the like. The communication device 1004 includes, for example, a high frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). It may be configured to include. For example, the above-described transmitting/receiving unit 120 (220), transmitting/receiving antenna 130 (230), etc. may be realized by the communication device 1004. The transmitter/receiver 120 (220) may be physically or logically separated into a transmitter 120a (220a) and a receiver 120b (220b).

The input device 1005 is an input device (eg, keyboard, mouse, microphone, switch, button, sensor, etc.) that accepts input from the outside. The output device 1006 is an output device (for example, a display, a speaker, a light emitting diode (LED) lamp, etc.) that performs output to the outside. Note that 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 configured using a single bus, or may be configured using different buses for each device.

The base station 10 and the user terminal 20 also include a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), a field programmable gate array (FPGA), etc. It may be configured to include hardware, and a part or all of each functional block may be realized using the hardware. For example, processor 1001 may be implemented using at least one of these hardwares.

(Modified example)
Note that terms explained in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings. For example, channel, symbol and signal may be interchanged. Also, the signal may be a message. The reference signal may also be abbreviated as RS, and may be called a pilot, pilot signal, etc. depending on the applicable standard. Further, a component carrier (CC) may be called a cell, a frequency carrier, a carrier frequency, or the like.

A radio frame may be composed of one or more periods (frames) in the time domain. Each of the one or more periods (frames) constituting a radio frame may be called a subframe. Furthermore, a subframe may be composed of one or more slots in the time domain. A subframe may have a fixed time length (eg, 1 ms) that does not depend on numerology.

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

A slot may be constituted by one or more symbols (Orthogonal Frequency Division Multiplexing (OFDM) symbols, Single Carrier Frequency Division Multiple Access (SC-FDMA) symbols, etc.) in the time domain. Furthermore, a slot may be a time unit based on numerology.

A slot may include multiple minislots. Each minislot may be made up of one or more symbols in the time domain. Furthermore, a mini-slot may also be called a sub-slot. A minislot may be made up of fewer symbols than a slot. PDSCH (or PUSCH) transmitted in time units larger than minislots may be referred to as PDSCH (PUSCH) mapping type A. PDSCH (or PUSCH) transmitted using minislots may be referred to as PDSCH (PUSCH) mapping type B.

Radio frames, subframes, slots, minislots, and symbols all represent time units for transmitting signals. Other names may be used for the radio frame, subframe, slot, minislot, and symbol. Note that time units such as frames, subframes, slots, minislots, and symbols in the present disclosure may be read interchangeably.

For example, one subframe may be called a TTI, multiple consecutive subframes may be called a TTI, and one slot or minislot may be called a TTI. In other words, at least one of the subframe and TTI may be a subframe (1ms) in existing LTE, a period shorter than 1ms (for example, 1-13 symbols), or a period longer than 1ms. It may be. Note that the unit representing the TTI may be called a slot, minislot, etc. instead of a subframe.

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

The TTI may be a transmission time unit of a channel-coded data packet (transport block), a code block, a codeword, etc., or may be a processing unit of scheduling, link adaptation, etc. Note that when a TTI is given, the time interval (for example, the number of symbols) to which transport blocks, code blocks, code words, etc. are actually mapped may be shorter than the TTI.

Note that when one slot or one minislot is called a TTI, one or more TTIs (that is, one or more slots or one or more minislots) may be the minimum time unit for scheduling. Further, the number of slots (minislot number) that constitutes the minimum time unit of the scheduling may be controlled.

A TTI having a time length of 1 ms may be called a normal TTI (TTI in 3GPP Rel. 8-12), normal TTI, long TTI, normal subframe, normal subframe, long subframe, slot, etc. A TTI that is shorter than a normal TTI may be referred to as an abbreviated TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, or the like.

Note that long TTI (for example, normal TTI, subframe, etc.) may be read as TTI with a time length exceeding 1 ms, and short TTI (for example, short TTI, etc.) It may also be read as a TTI having the above TTI length.

A resource block (RB) is a unit of resource allocation in the time domain and frequency domain, and may include one or more continuous subcarriers (subcarriers) in the frequency domain. The number of subcarriers included in an RB may be the same regardless of the numerology, and may be 12, for example. The number of subcarriers included in an RB may be determined based on numerology.

Additionally, an RB may include one or more symbols in the time domain and may be one slot, one minislot, one subframe, or one TTI long. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

Note that one or more RBs include a physical resource block (Physical RB (PRB)), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, and an RB. They may also be called pairs.

Further, a resource block may be configured by one or more resource elements (REs). For example, 1 RE may be a radio resource region of 1 subcarrier and 1 symbol.

Bandwidth Part (BWP) (also called partial bandwidth, etc.) refers to a subset of contiguous common resource blocks (RBs) for a certain numerology in a certain carrier. Good too. Here, the common RB may be specified by an RB index based on a common reference point of the carrier. PRBs may be defined in a BWP and numbered within that BWP.

BWP may include UL BWP (BWP for UL) and DL BWP (BWP for DL). One or more BWPs may be configured within one carrier for a UE.

At least one of the configured BWPs may be active and the UE may not expect to transmit or receive a given signal/channel outside of the active BWP. Note that "cell", "carrier", etc. in the present disclosure may be replaced with "BWP".

Note that the structures of the radio frame, subframe, slot, minislot, symbol, etc. described above are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of symbols included in an RB, The number of subcarriers, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, and other configurations can be changed in various ways.

In addition, the information, parameters, etc. described in this disclosure may be expressed using absolute values, relative values from a predetermined value, or using other corresponding information. may be expressed. For example, radio resources may be indicated by a predetermined index.

The names used for parameters and the like in this disclosure are not limiting in any respect. Furthermore, the mathematical formulas etc. using these parameters may differ from those explicitly disclosed in this disclosure. Since the various channels (PUCCH, PDCCH, etc.) and information elements can be identified by any suitable designation, the various names assigned to these various channels and information elements are not in any way exclusive designations. .

The information, signals, etc. described in this disclosure may be represented using any of a variety of different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc., which may be referred to throughout the above description, may refer to voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these. It may also be represented by a combination of

Further, information, signals, etc. may be output from the upper layer to the lower layer and from the lower layer to at least one of the upper layer. Information, signals, etc. may be input and output via multiple network nodes.

Input/output information, signals, etc. may be stored in a specific location (eg, memory) or may be managed using a management table. Information, signals, etc. that are input and output can be overwritten, updated, or added. The output information, signals, etc. may be deleted. The input information, signals, etc. may be transmitted to other devices.

Notification of information is not limited to the aspects/embodiments described in this disclosure, and may be performed using other methods. For example, the information notification in this disclosure may be performed using physical layer signaling (e.g., Downlink Control Information (DCI), uplink control information (UCI)), upper layer signaling (e.g., Radio Resource Control (RRC) signaling, broadcast information (Master Information Block (MIB), System Information Block (SIB), etc.), Medium Access Control (MAC) signaling), other signals, or a combination thereof. It may be carried out by

Note that the physical layer signaling may be called Layer 1/Layer 2 (L1/L2) control information (L1/L2 control signal), L1 control information (L1 control signal), etc. Further, RRC signaling may be called an RRC message, and may be, for example, an RRC Connection Setup message, an RRC Connection Reconfiguration message, or the like. Further, MAC signaling may be notified using, for example, a MAC Control Element (CE).

Further, notification of prescribed information (for example, notification of "X") is not limited to explicit notification, but may be made implicitly (for example, by not notifying the prescribed information or by providing other information) (by notification).

The determination may be made by a value expressed by 1 bit (0 or 1), or by a boolean value expressed by true or false. , may be performed by numerical comparison (for example, comparison with a predetermined value).

Software includes instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, whether referred to as software, firmware, middleware, microcode, hardware description language, or by any other name. , should be broadly construed to mean an application, software application, software package, routine, subroutine, object, executable, thread of execution, procedure, function, etc.

Additionally, software, instructions, information, etc. may be sent and received via a transmission medium. For example, if the software uses wired technology (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), etc.) and/or wireless technology (such as infrared, microwave) to , a server, or other remote source, these wired and/or wireless technologies are included within the definition of a transmission medium.

As used in this disclosure, the terms "system" and "network" may be used interchangeably. "Network" may refer to devices (eg, base stations) included in the network.

In this disclosure, "precoding", "precoder", "weight (precoding weight)", "quasi-co-location (QCL)", "Transmission Configuration Indication state (TCI state)", "spatial "spatial relation", "spatial domain filter", "transmission power", "phase rotation", "antenna port", "antenna port group", "layer", "number of layers", Terms such as "rank", "resource", "resource set", "resource group", "beam", "beam width", "beam angle", "antenna", "antenna element", and "panel" are interchangeable. can be used.

In this disclosure, "Base Station (BS)", "Wireless base station", "Fixed station", "NodeB", "eNB (eNodeB)", "gNB (gNodeB)", "Access point", "Transmission Point (TP)", "Reception Point (RP)", "Transmission/Reception Point (TRP)", "Panel" , "cell," "sector," "cell group," "carrier," "component carrier," and the like may be used interchangeably. A base station is sometimes referred to by terms such as macrocell, small cell, femtocell, and picocell.

A base station can accommodate one or more (eg, three) cells. If a base station accommodates multiple cells, the overall coverage area of the base station can be partitioned into multiple smaller areas, and each smaller area is divided into base station subsystems (e.g., small indoor base stations (Remote Radio Communication services can also be provided by the Head (RRH)). The term "cell" or "sector" refers to part or all of the coverage area of a base station and/or base station subsystem that provides communication services in this coverage.

In this disclosure, terms such as "Mobile Station (MS)," "user terminal," "User Equipment (UE)," and "terminal" are used interchangeably. can be done.

A mobile station is a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal. , handset, user agent, mobile client, client, or some other suitable terminology.

At least one of a base station and a mobile station may be called a transmitting device, a receiving device, a wireless communication device, or the like. Note that at least one of the base station and the mobile station may be a device mounted on a mobile body, the mobile body itself, or the like. The moving object may be a vehicle (for example, a car, an airplane, etc.), an unmanned moving object (for example, a drone, a self-driving car, etc.), or a robot (manned or unmanned). ). Note that at least one of the base station and the mobile station includes devices that do not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an Internet of Things (IoT) device such as a sensor.

Furthermore, the base station in the present disclosure may be replaced by a user terminal. For example, communication between a base station and a user terminal is replaced with communication between multiple user terminals (for example, it may be called Device-to-Device (D2D), Vehicle-to-Everything (V2X), etc.). Regarding the configuration, each aspect/embodiment of the present disclosure may be applied. In this case, the user terminal 20 may have the functions that the base station 10 described above has. Further, words such as "upstream" and "downstream" may be replaced with words corresponding to inter-terminal communication (for example, "side"). For example, uplink channels, downlink channels, etc. may be replaced with side channels.

Similarly, the user terminal in the present disclosure may be replaced by a base station. In this case, the base station 10 may have the functions that the user terminal 20 described above has.

In this disclosure, the operations performed by the base station may be performed by its upper node in some cases. In a network including one or more network nodes having a base station, various operations performed for communication with a terminal may be performed by the base station, one or more network nodes other than the base station (e.g. It is clear that this can be done by a Mobility Management Entity (MME), a Serving-Gateway (S-GW), etc. (but not limited to these) or a combination thereof.

Each aspect/embodiment described in this disclosure may be used alone, may be used in combination, or may be switched and used in accordance with execution. Further, the order of the processing procedures, sequences, flowcharts, etc. of each aspect/embodiment described in this disclosure may be changed as long as there is no contradiction. For example, the methods described in this disclosure use an example order to present elements of the various steps and are not limited to the particular order presented.

Each aspect/embodiment described in this disclosure is applicable to Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system ( 4G), 5th generation mobile communication system (5G), Future Radio Access (FRA), New-Radio Access Technology (RAT), New Radio (NR), New radio access (NX), Future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802. 20, Ultra-WideBand (UWB), Bluetooth (registered trademark), and other appropriate wireless communication methods, and next-generation systems expanded based on these may be applied. Furthermore, a combination of multiple systems (for example, a combination of LTE or LTE-A and 5G) may be applied.

As used in this disclosure, the phrase "based on" does not mean "based solely on" unless explicitly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

As used in this disclosure, the terms "connected", "coupled", or any variations thereof refer to any connection or coupling, direct or indirect, between two or more elements. can include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. For example, "connection" may be replaced with "access."

In this disclosure, when two elements are connected, they may be connected using one or more electrical wires, cables, printed electrical connections, etc., as well as in the radio frequency domain, microwave can be considered to be "connected" or "coupled" to each other using electromagnetic energy having wavelengths in the light (both visible and invisible) range.

In the present disclosure, the term "A and B are different" may mean "A and B are different from each other." Note that the term may also mean that "A and B are each different from C". Terms such as "separate" and "coupled" may also be interpreted similarly to "different."

Where "include", "including" and variations thereof are used in this disclosure, these terms are inclusive, as is the term "comprising". It is intended that Furthermore, the term "or" as used in this disclosure is not intended to be exclusive or.

In this disclosure, when articles are added by translation, such as a, an, and the in English, the disclosure may include that the nouns following these articles are plural.

Although the invention according to the present disclosure has been described in detail above, it is clear for those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The invention according to the present disclosure can be implemented as modifications and variations without departing from the spirit and scope of the invention as determined based on the claims. Therefore, the description of the present disclosure is for the purpose of illustrative explanation and does not have any limiting meaning on the invention according to the present disclosure.

Claims (4)

When there are multiple terminals with different numbers of ports that can be set as demodulation reference signals, the first demodulation reference signal transmitted to another terminal among the multiple terminals and the first demodulation reference signal transmitted to another terminal among the multiple terminals a control unit that assumes that a different code division multiplexing (CDM) group is applied to a second demodulation reference signal transmitted to the own terminal;
a receiving unit that receives the second demodulation reference signal at a port in a CDM group different from the port assigned to the first demodulation reference signal transmitted to the other terminal;
A terminal characterized by having. When there are multiple terminals with different numbers of ports that can be set as demodulation reference signals, the first demodulation reference signal transmitted to another terminal among the multiple terminals and the first demodulation reference signal transmitted to another terminal among the multiple terminals a step of assuming that a different code division multiplexing (CDM) group is applied to the second demodulation reference signal transmitted to the own terminal;
receiving the second demodulation reference signal at a port in a different CDM group from the port assigned to the first demodulation reference signal transmitted to the other terminal;
A wireless communication method for a terminal , comprising: When there are multiple terminals with different numbers of ports that can be set as demodulation reference signals, a first demodulation reference signal to be transmitted to a first terminal among the multiple terminals, and a first demodulation reference signal to be transmitted to a first terminal among the multiple terminals; a control unit that applies a different code division multiplexing (CDM) group to a second demodulation reference signal transmitted to a second terminal of the controller;
a transmitter that transmits the second demodulation reference signal at a port in a different CDM group from a port assigned to the first demodulation reference signal transmitted to the first terminal;
A base station with a A system including a terminal and a base station,
The terminal is
When there are multiple terminals with different numbers of ports that can be set as demodulation reference signals, the first demodulation reference signal transmitted to another terminal among the multiple terminals and the first demodulation reference signal transmitted to another terminal among the multiple terminals a control unit that assumes that a different code division multiplexing (CDM) group is applied to a second demodulation reference signal transmitted to the own terminal;
a receiving unit that receives the second demodulation reference signal at a port in a CDM group different from the port assigned to the first demodulation reference signal transmitted to the other terminal;
A system with.

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