KR20200009928A - Apparatus and method of multiple subbands operation in NR - Google Patents

Abstract

The present invention proposes a method for operating multiple BWPs in next generation wireless network. More particularly, the present invention specifically describes a method and a terminal operation for a specific instruction for monitoring between the existing BWP and a moved BWP during BWP switching. According to an embodiment of the present invention, provided is a method of controlling at least one bandwidth part in a next generation wireless network, which indicates whether to monitor the bandwidth part activated before switching through DCI.

Description

Apparatus and method of multiple subbands operation in NR}

The present invention proposes a multiple BWP operation method in NR. In particular, it describes in detail the specific instruction method and the operation of the terminal for monitoring between the existing BWP and the moved BWP during BWP switching.

One embodiment is a method for controlling one or more bandwidth parts in a next generation wireless network, wherein when switching on the bandwidth part occurs, indicating whether to monitor the bandwidth part activated before the switching through DCI. It provides a method characterized by.

1 illustrates an example of symbol level alignment among different SCSs.
2 illustrates NR time domain structure depending on subcarrier-spacing.
3 is a diagram illustrating a conceptual example of a bandwidth part.
4 is a conceptual diagram of a multi BWP operation using a BWP monitoring field (when ON is set).
5 is a conceptual diagram of a multi BWP operation using the BWP monitoring field (when OFF is set).
FIG. 6 is a diagram illustrating an example of previous BWP scheduling data drop in method 1. FIG.
FIG. 7 is a diagram illustrating an example of monitoring off after transmitting previous BWP scheduling data in scheme 2. FIG.
8 is a diagram illustrating a configuration of a base station according to another embodiment.
9 is a diagram illustrating a configuration of a user terminal according to another embodiment.

Hereinafter, some embodiments of the present invention will be described in detail through exemplary drawings. In adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used to refer to the same components as much as possible, even if displayed on different drawings. In addition, in describing the present invention, if it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

In the present specification, the wireless communication system refers to a system for providing various communication services such as voice and packet data. The wireless communication system includes a user equipment (UE) and a base station (BS).

A user terminal is a comprehensive concept of a terminal in a wireless communication, and includes a user equipment (UE) in WCDMA, LTE, HSPA, and IMT-2020 (5G or New Radio), as well as a mobile station (MS) and a UT in GSM. It should be interpreted as a concept that includes a user terminal, a subscriber station (SS), and a wireless device.

A base station or cell generally refers to a station for communicating with a user terminal, and includes a Node-B, an evolved Node-B, an eNB, a gNode-B, and a Low Power Node. ), Sector, site, various types of antenna, base transceiver system (BTS), access point, access point (for example, transmission point, reception point, transmission / reception point), relay node ( It is meant to encompass various coverage areas such as relay nodes, mega cells, macro cells, micro cells, pico cells, femto cells, remote radio heads (RRHs), radio units (RUs), and small cells.

Since the various cells listed above have a base station for controlling each cell, the base station may be interpreted in two meanings. 1) the device providing the mega cell, the macro cell, the micro cell, the pico cell, the femto cell, the small cell in relation to the radio area, or 2) the radio area itself. In 1) all devices that provide a given wireless area are controlled by the same entity or interact with each other to cooperatively configure the wireless area to the base station. According to the configuration of the wireless area, a point, a transmission point, a transmission point, a reception point, and the like become one embodiment of a base station. In 2), the base station may indicate the radio area itself that receives or transmits a signal from a viewpoint of a user terminal or a neighboring base station.

In the present specification, a cell refers to a component carrier having coverage of a signal transmitted from a transmission / reception point or a signal transmitted from a transmission point or a transmission / reception point, and the transmission / reception point itself. Can be.

In the present specification, the user terminal and the base station are used in a comprehensive sense as two entities (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by the terms or words specifically referred to. Do not.

Here, the uplink (Uplink, UL, or uplink) refers to a method for transmitting and receiving data to the base station by the user terminal, the downlink (Downlink, DL, or downlink) means to transmit and receive data to the user terminal by the base station It means the way.

The uplink transmission and the downlink transmission may use a time division duplex (TDD) scheme that is transmitted using different times, and a frequency division duplex (FDD) scheme, a TDD scheme and a FDD scheme, which are transmitted using different frequencies. Mixed mode may be used.

In addition, in a wireless communication system, uplink and downlink are configured based on one carrier or a pair of carriers to configure a standard.

The uplink and the downlink transmit control information through a control channel such as a physical downlink control channel (PDCCH), a physical uplink control channel (PUCCH), a physical downlink shared channel (PDSCH), a physical uplink shared channel (PUSCH), and the like. It is composed of the same data channel to transmit data.

Downlink (downlink) may mean a communication or communication path from the multiple transmission and reception points to the terminal, uplink (uplink) may mean a communication or communication path from the terminal to the multiple transmission and reception points. In this case, in the downlink, the transmitter may be part of multiple transmission / reception points, and the receiver may be part of the terminal. In addition, in uplink, a transmitter may be part of a terminal, and a receiver may be part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted and received through a channel such as a PUCCH, a PUSCH, a PDCCH, and a PDSCH may be described in the form of 'sending and receiving a PUCCH, a PUSCH, a PDCCH, and a PDSCH.'

Meanwhile, high layer signaling described below includes RRC signaling for transmitting RRC information including an RRC parameter.

The base station performs downlink transmission to the terminals. The base station transmits downlink control information such as scheduling required for reception of a downlink data channel, which is a main physical channel for unicast transmission, and a physical downlink for transmitting scheduling grant information for transmission on an uplink data channel. The control channel can be transmitted. Hereinafter, the transmission and reception of signals through each channel will be described in the form of transmission and reception of the corresponding channel.

There is no limitation on the multiple access scheme applied in the wireless communication system. Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Code Division Multiple Access (CDMA), Orthogonal Frequency Division Multiple Access (OFDMA), Non-Orthogonal Multiple Access (NOMA), OFDM-TDMA, OFDM-FDMA, Various multiple access techniques such as OFDM-CDMA can be used. Here, the NOMA includes a sparse code multiple access (SCMA) and a low density spreading (LDS).

One embodiment of the present invention is to asynchronous radio communication evolving to LTE / LTE-Advanced, IMT-2020 via GSM, WCDMA, HSPA, and synchronous radio communication evolving to CDMA, CDMA-2000 and UMB Can be applied.

In the present specification, a MTC terminal may mean a terminal supporting low cost (or low complexity) or a terminal supporting coverage enhancement. Alternatively, in the present specification, the MTC terminal may mean a terminal defined in a specific category for supporting low cost (or low complexity) and / or coverage enhancement.

In other words, in the present specification, the MTC terminal may mean a newly defined 3GPP Release-13 low cost (or low complexity) UE category / type for performing LTE-based MTC related operations. Alternatively, in the present specification, the MTC terminal supports an enhanced coverage compared to the existing LTE coverage, or UE category / type defined in the existing 3GPP Release-12 or lower, or newly defined Release-13 low cost (or supporting low power consumption). low complexity) can mean UE category / type. Or, it may mean a further Enhanced MTC terminal defined in Release-14.

In the present specification, a NB-IoT (NarrowBand Internet of Things) terminal refers to a terminal that supports radio access for cellular IoT. The objectives of the NB-IoT technology include improved indoor coverage, support for large scale low speed terminals, low sensitivity, low cost terminal cost, low power consumption, and optimized network architecture.

As a typical usage scenario in NR (New Radio), which is recently discussed by 3GPP, enhanced Mobile BroadBand (eMBB), Massive Machine Type Communication (MMTC), and Ultra Reliable and Low Latency Communication (URLLC) are being raised.

In this specification, frequencies, frames, subframes, resources, resource blocks, regions, bands, subbands, control channels, data channels, synchronization signals, various reference signals, various signals, and various messages related to NR (New Radio). May be interpreted as meaning used in the past or present, or various meanings used in the future.

[5G NR (New Rat)]

3GPP supports a frame structure based on multiple subcarriers in the NR frame structure.

Here, the default SCS is 15 kHz, which supports a total of five SCS types at 15 kHz x 2μ. SCS values according to μ values are shown in Table 1 below.

As shown in FIG. 1, slot lengths may vary depending on numerology. That is, the shorter the slot length, the larger the SCS. In addition, slots defined in NR are defined based on 14 OFDM symbols.

- NR Time domain structure

NR supports the following structures on the time axis: Here, the difference from the existing LTE, the basic scheduling unit is changed to a slot in the NR. In addition, regardless of subcarrier-spacing, the slot has 14 OFDM symbols as shown in FIG. 2. On the other hand, it supports a non-slot structure consisting of 2, 4, and 7 OFDM symbols, which are smaller scheduling units. The non-slot structure may be utilized as a scheduling unit for URLLC service.

■ Radio frame: Fixed 10ms regardless of numerology

■ Subframe: Fixed 1ms as a reference for time duration

  ◆ Do not use for data / control scheduling unit

■ Slot: Mainly for eMBB

  ◆ Include 14 OFDM symbols

■ Non-slot (i.e. mini-slot)

  ◆ Mainly for URLLC, but not limited to URLLC only

  ◆ Include 2, 4, or 7 OFDM symbols

■ One TTI duration

  ◆ A Time duration for data / control channel transmission

  ◆ A number of OFDM symbols per a slot / non-slot in the time main

[NR-U]

Unlike licensed bands, unlicensed bands are available for the provision of wireless communications services by any operator or individual within the regulation of each country, rather than a wireless channel exclusively used by any operator. Accordingly, when providing NR service through unlicensed band, co-existence problem with various short-range wireless communication protocols such as WiFi, Bluetooth, NFC, etc. already provided through the unlicensed band and co-existence between each NR provider or LTE provider The problem needs to be solved. Accordingly, when providing NR service through the unlicensed band, the power level of the radio channel or carrier to be used is sensed before transmitting the radio signal in order to avoid interference or collision between the respective radio communication services to determine whether the corresponding radio channel or carrier is available. There is a need to support an LBT (Listen Before Talk) based wireless channel access method. In this case, if a specific wireless channel or carrier in the unlicensed band is in use by another wireless communication protocol or another operator, the wireless communication service in the unlicensed band may be restricted to the provision of NR service through the band. Unlike the wireless communication service through a wireless network, it is difficult to guarantee the QoS required by the user. In particular, in the case of NR-U, unlike the existing LTE, which must support unlicensed spectrum through CA with licensed spectrum, as a deployment scenario of unlicensed band NR, stand-alone NR-U cell or licensed band NR cell or LTE cell There is a need for a design of a data transmission / reception method to satisfy an appropriate QoS.

In addition, NR-Us that use unlicensed bands must also support BWP operations to efficiently use wideband NR CCs. In order to make good use of the unlicensed band, it may be good to map one BWP to one WiFi channel. However, no specific method is provided for BWP operation in NR-U. In particular, NR-U may not guarantee an appropriate level of QoS due to LBT. In order to overcome this problem, QoS can be improved if a plurality of BWPs are activated and used, but the current NR specification does not support this.

[Bandwidth Part operations]

In the case of the existing LTE system, it supports scalable bandwidth operation for any LTC CC (Component Carrier). That is, according to the frequency deployment scenario, any LTE operator may configure a bandwidth of at least 1.4 MHz and up to 20 MHz in configuring one LTE CC, and a normal LTE terminal may have a bandwidth of 20 MHz for one LTE CC. Supports transmit and receive capability.

However, in the case of NR, it is designed to support NR terminals having different transmit / receive bandwidth capabilities through one wideband NR CC. Accordingly, as shown in FIG. One or more configured bandwidth part (s) is configured to support flexible wider bandwidth operation through different bandwidth part configuration and activation for each terminal.

In more detail, in NR, one or more bandwidth parts may be configured through one serving cell configured from a terminal perspective, and the corresponding UE activates one DL bandwidth part and one UL bandwidth part in the corresponding serving cell and uplink / downlink data. It is defined to be used for sending and receiving. In addition, when a plurality of serving cells are configured in the corresponding UE, that is, even for a UE to which CA is applied, one DL bandwidth part and / or UL bandwidth part is activated for each serving cell to use uplink / downlink radio resources of the corresponding serving cell. It is defined to be used for link data transmission and reception.

Specifically, an initial bandwidth part for an initial access procedure of a terminal is defined in an arbitrary serving cell, one or more UE-specific bandwidth parts (s) are configured through dedicated RRC signaling for each terminal, and fallback for each terminal. A default bandwidth part for operation can be defined.

However, in the NR standard, any one terminal is defined to activate and use only one DL bandwidth part and UL bandwidth part at any time.

Currently, NR-U is considering stand-alone design for unlicensed bands. At this time, in order to increase the probability of LBT success, multiple bandwidth parts (BWP) and subband scheduling are considered. However, there is currently no specific method for multiple BWP operation and scheduling. In particular, when using multiple BWPs, based on the existing single BWP operation method, various cases between the current BWP and the switched BWP may not be supported or errors may occur.

The present invention proposes a multiple BWP operation method in NR. In particular, it describes in detail the specific instruction method and the operation of the terminal for monitoring between the existing BWP and the moved BWP during BWP switching.

Currently, NR is conducting a Rel-16 Study Item called 'NR-based Access to Unlicensed Spectrum' for unlicensed band access. The agreement regarding channel access procedure for NR-U is as follows.

Agreement:

● LTE-LAA channel access mechanism is adopted as baseline for 5 GHz

o Further enhancements not precluded

● LTE-LAA channel access mechanism is adopted as starting point of the design for 6 GHz

o Further enhancements not precluded

● For 5GHz band, a no-LBT option is beneficial for NR-U, such as for supporting fast A / N feedback, and is permitted per regulation.

o Restrictions / conditions on when no-LBT option can be used will be further identified, e.g., in consideration of fair coexistence.

● No-LBT option can be applied to 6GHz band if allowed by regulation

o Restrictions / conditions on when no-LBT option can be used will be further identified, if fair coexistence criterion is defined for 6GHz band

Note: Channel access mechanisms need to comply with regulations and may therefore need to be adapted for particular frequency ranges.

Agreement:

● Initial active DL / UL BWP is approximately 20MHz for 5GHz band

o The final value will be quantized to number of PRBs

● Initial active DL / UL BWP is approximately 20MHz for 6GHz band if similar channelization as 5GHz band is used for 6GHz band

● FFS: Initial active DL / UL BWP for other applicable bands, including 60 GHz

In the present invention, the multiple BWP switching method for NR is described above. Basically, this proposal is applicable for NR / NR-U. Therefore, the following description is based on a proposal and a scheme common to multiple BWP operations that can be applied to both NR-U / NR.

Scheme 1. When BWP switching occurs, whether to monitor the existing BWP may refer to DCI.

The Rel-15 NR supported single BWP operation. That is, the terminal always operates only a single BWP, and refers to the bandwidth part indicator to move within the DCI when switching BWPs. This information can be found in the information field description section of the DCI format below.

For example, if a single BWP switching is described, the current UE receives the PDCCH at BWP # 0. If the scheduling information in DCI is set to Bandwidth part indicator = 1, the UE switches to BWP # 1 for data reception and switches to BWP # 0. It does not operate for. That is, the terminal no longer monitors BWP # 0.

In this proposal, when switching for operating multiple BWPs in this environment, the corresponding signaling is newly added in DCI as to whether or not to perform previous BWP monitoring. This field can be defined as N_mornitoring, which can be set as a single bit. For example, if N_mornitoring is 1 bit, the following two cases can be considered.

- Case 1: N_mornitoring = ON

■ When switching BWP # X-> BWP # Y, keep BWP # X as it is. That is, after switching to BWP # X-> BWP # Y, the UE performs PDCCH monitoring for both BWP # X and BWP # Y.

■ For example, when receiving scheduling information of BWP # 1 in BWP # 0 as shown in FIG. 4, when BWP switching is possible in consideration of its capability, the UE may receive PDSCH data in BWP # 1. At this time, in the existing operation, the UE no longer performs PDCCH monitoring in BWP # 0. However, considering multiple BWP operation, data can still be received even in BWP # 0. Therefore, BWP # 0 and switched BWP # 1 can be monitored at the same time by setting BWP monitoring field to 'ON' in DCI, which refers to BWP switching.

- Case 2: N_mornitoring = OFF

■ When switching BWP # X-> BWP # Y, BWP # X is not received. That is, after switching to BWP # X-> BWP # Y, the UE performs PDCCH monitoring only for BWP # Y.

■ For example, when receiving scheduling information of BWP # 1 in BWP # 0 as shown in FIG. 5, when the BWP switching is possible in consideration of its capability, the UE may receive PDSCH data in BWP # 1. At this time, when the terminal needs to operate a single BWP as in the existing operation, set the BWP monitoring field to 'OFF'. Through this, the UE no longer performs PDCCH monitoring in BWP # 0.

Scheme 2. In BWPs where different scheduling points overlap, a specific time point can be designated separately to indicate whether to monitor.

In Rel-15 NR, 'Time domain resource assignment' field is added as below to indicate between PDCCH reception time and actual scheduling time. In conventional LTE, the time point is fixed to in + subframe for PDCCH-> PDSCH scheduling and n + 4 suframe for PDCCH-> PUSCH scheduling. However, in the NR, as described above, the slot in which the PDCCH is detected and the slot timing in which the actual scheduling is applied can be directly designated. Therefore, in this proposal, we propose a solution to solve the mismatch problem that may occur between the time when scheduling information is received and the time when actual data transmission occurs, such as Case-1 and Case-2, when applying multiple BWP-based BWP switching. In this case, the BWP monitoring field of the proposed method 1 can be applied to both or not.

Case-1: PDCCH scheduling with different scheduling points

■ When the BWP switching timing and the existing BWP scheduling timing do not match, the UE may define the following two operations.

◆ Method 1: Change the monitoring BWP to match the BWP switching time point and stop all transmission of the existing BWP. If the PDSCH / PUSCH that has been scheduled for transmission is dropped or rescheduled at the changed BWP, the PDSCH / PUSCH attempts transmission. That is, if the UE receives the scheduling information to turn off BWP # 0 through the BWP monitoring field as shown in FIG.

→ BWP switching is performed regardless of the transmission time of the scheduling data.

◆ Scheme 2: If the existing BWP scheduling point is behind the BWP switching point, the existing BWP is not turned off during the last scheduling period. That is, in case that PDSCH / PUSCH to be scheduled and transmitted to the existing BWP remains, the corresponding BWP is turned off after all the data is transmitted. That is, even if the UE receives scheduling information to turn off BWP # 0 through the BWP monitoring field as shown in FIG.

→ BWP switching is completed after finishing the latest data transmission. Perform BWP switching regardless of which is the latest in time.

Case-2: SPS Scheduling and PDCCH Scheduling Are Different

■ If the SPS transmission is in progress to the existing BWP where the BWP switching occurs, turn off the corresponding BWP after the SPS transmission is completely terminated. Hereinafter, the operation principle is the same as in the case 2 of Case-1.

The present invention proposes a multiple BWP operation method in NR. In particular, it describes in detail the specific instruction method and the operation of the terminal for monitoring between the existing BWP and the moved BWP during BWP switching.

8 is a diagram illustrating a configuration of a base station 1000 according to another embodiment.

Referring to FIG. 8, the base station 1000 according to another embodiment includes a controller 1010, a transmitter 1020, and a receiver 1030.

The control unit 1010 is a method for controlling one or more bandwidth parts in the next-generation wireless network required to implement the above-described invention, when switching to the bandwidth part occurs, the bandwidth part that was activated before switching It controls the overall operation of the base station 1000 according to the method characterized in that indicating whether or not to monitor over the DCI.

The transmitter 1020 and the receiver 1030 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention.

9 is a diagram illustrating a configuration of a user terminal 1100 according to another embodiment.

Referring to FIG. 9, a user terminal 1100 according to another embodiment includes a receiver 1110, a controller 1120, and a transmitter 1130.

The receiver 1110 receives downlink control information, data, and a message from a base station through a corresponding channel.

In addition, the control unit 1120 is a method for controlling one or more bandwidth parts in the next-generation wireless network required to perform the present invention described above, when switching on the bandwidth part, the bandwidth part that was activated before switching Controls the overall operation of the user terminal 1100 according to the method of instructing whether or not to monitor through the DCI.

The transmitter 1130 transmits uplink control information, data, and a message to a base station through a corresponding channel.

Also, terms such as "system", "processor", "controller", "component", "module", "interface", "model", "unit" generally refer to computer-related entity hardware, a combination of hardware and software, May mean software or running software. For example, the aforementioned components may be, but are not limited to, a process driven by a processor, a processor, a controller, a control processor, an object, an execution thread, a program, and / or a computer. For example, both an application running on a controller or processor and a controller or processor can be components. One or more components can reside within a process and / or thread of execution and a component can be located on one system or deployed on more than one system.

The standard contents or standard documents mentioned in the above embodiments are omitted to simplify the description of the specification and form a part of the present specification. Therefore, the addition of the contents of the above standards and some of the standard documents to the specification or the claims should be construed as falling within the scope of the present invention.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

Claims (1)

In the method for controlling one or more bandwidth parts in the next generation wireless network,
When switching for the bandwidth part occurs, indicating whether to monitor for the bandwidth part activated before the switching through the DCI.

Images