WO2021159303A1

WO2021159303A1 - Methods and apparatus of scell activation in new radio system

Info

Publication number: WO2021159303A1
Application number: PCT/CN2020/074874
Authority: WO
Inventors: Zhixun Tang; Tsang-Wei Yu; Hsuan-Li Lin
Original assignee: Mediatek Singapore Pte. Ltd.
Priority date: 2020-02-12
Filing date: 2020-02-12
Publication date: 2021-08-19
Also published as: TWI762192B; TW202131723A; CN113259967B; CN113259967A

Abstract

When there is no active serving cell on this FR2 band and all SCells to-be-activated belongs to the same intra-band, the SCell activation can be defined as known and unknown condition. If all of the multiple SCell activation can be unknown SCells and if single MAC CE command for these multiple SCells, only one unknown SCell needs to execute cell search and L1-RSRP measurement. Other unknown SCells just hold on the activation procedure until one of the unknown SCell finishing the cell search and L1-RSRP measurement. After that all unknown SCells will wait their TCI configuration from network and execute their SCell activation process independently. It shall be noted that although the TCI configuration for QCL TypeD RS shall be the same source SSB, the TCI configuration for these unknown SCells shall still be different because each serving cell's timing/Doppler configuration RS bases on its serving cell's information independently. If at least one of the multiple SCell activation can be known SCell and one of the multiple SCell activation can be unknown SCell and if single MAC CE command for these multiple SCells, the unknown SCell won' t need these cell search, L1-RSRP measurement and reporting procedure. Unknown SCells will wait PDCCH TCI, PDSCH TCI, CSI-RS reporting configuration and SCell activation command. After that, the Unknown SCells will also have the same activation procedure as known SCell. Owing to the TCI and CSI-RS configuration for each SCell may not come at the same time. The RF retuning occasion for each SCell shall also different, but as we discussed above, UE can schedule the RF retuning occasion to avoid the collision with SSB for timing tracking. Thus, no additional interruption is needed in this scenario. When SCells to-be-activated belongs to the inter-band, UE shall be allowed to use different Rx/Tx beams on 2 CCs at a time. Multiple SCell activation shall be sequential. It means L1-RSRP measurement and reporting procedure shall be extended for each inter-band FR2 SCells.

Description

METHODS AND APPARATUS OF SCELL ACTIVATION IN NEW RADIO SYSTEM

TECHNICAL FIELD

The present disclosure relates to wireless communications, and particularly relates to SCell activation processing in a New Radio system.

BACKGROUND

The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.

The 5G New Radio (NR) system is designed to support sub-6GHz and mmWave. In mmWave, the NR system needs beam management process to set up the suitable Tx-Rx beam pair. To support higher throughput, the system could be deployed with carrier aggregation (CA) or dual-connection (DC) techniques. The network could activate one or multiple SCell (s) to increase the system throughput in CA or DC scenarios.

In LTE and NR SCell activation, the procedure should be SCell identification and CSI reporting. After UE receiving the SCell activation command by MAC-CE, UE should execute AGC retuning, cell search, fine synchronization, MIB reading for SCell identification. After SCell identification, the UE will calculate the CSI and reporting the CSI to the Base Station (BS) .

Nevertheless, for multiple SCell activation in NR mmWave, UE need to consider the beam management. Accordingly, the mechanism of multiple SCell activation in NR mmWave system is important.

SUMMARY

This invention proposes a mechanism of multiple SCell activation in a wireless communication network. The mechanism is used for an mmWave Scell activation scenario.

When there is no active serving cell on this FR2 band and all SCells to-be-activated belongs to the same intra-band, the SCell activation can be defined as known and unknown condition. If all of the multiple SCell activation can be unknown SCells and if single MAC CE command for these multiple SCells, only one unknown SCell needs to execute cell search and L1-RSRP measurement. Other unknown SCells just hold on the activation procedure until one of the unknown SCell finishing the cell search and L1-RSRP measurement. After that all unknown SCells will wait their TCI configuration from network and execute their SCell activation process independently. It shall be noted that although the TCI configuration for QCL TypeD RS shall be the same source SSB, the TCI configuration for these unknown SCells shall still be different because each serving cell’s timing/Doppler configuration RS bases on its serving cell’s information independently. If at least one of the multiple SCell activation can be known SCell and one of the multiple SCell activation can be unknown SCell and if single MAC CE command for these multiple SCells, the unknown SCell won’t need these cell search, L1-RSRP measurement and reporting procedure. Unknown SCells will wait PDCCH TCI, PDSCH TCI, CSI-RS reporting configuration and SCell activation command. After that, the Unknown SCells will also have the same activation procedure as known SCell. Owing to the TCI and CSI-RS configuration for each SCell may not come at the same time. The RF retuning occasion for each SCell shall also different, but as we discussed above, UE can schedule the RF retuning occasion to avoid the collision with SSB for timing tracking. Thus, no additional interruption is needed in this scenario.

When SCells to-be-activated belongs to the inter-band, UE shall be allowed to use different Rx/Tx beams on 2 CCs at a time. Multiple SCell activation shall be sequential. It means L1-RSRP measurement and reporting procedure shall be extended for each inter-band FR2 SCells.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of this disclosure that are proposed as examples will be described in detail with reference to the following figures, wherein like numerals reference like elements, and wherein:

Fig. 1 shows a wireless communication system according to an embodiment of the disclosure;

Fig. 2 shows an example of SCell activation procedure according to an embodiment of the disclosure;

Fig. 3 shows an example of SCell activation procedure according to an embodiment of the disclosure;

Fig. 4 shows an example of SCell activation procedure according to an embodiment of the disclosure;

Fig. 5 shows an exemplary block diagram of a user equipment (UE) according to an embodiment of the disclosure.

DETAILED DESCRIPTION

Fig. 1 shows a wireless communication system 100 according to an embodiment of the disclosure. The system 100 can include a user equipment (UE) 110 and a base station (BS) 120. The system 100 can be a cellular network, and employ the New Radio (NR) technologies and the LTE technologies developed by the 3rd Generation Partnership Project (3GPP) for wireless communications between the UE 110 and the BS 120. The UE 110 can be a mobile phone, a laptop computer, a device carried in a vehicle, and the like. The BS 120 can be an implementation of a gNB specified in NR standards. Accordingly, the UE 110 can communicate with the base station 120 through a wireless communication channel according to communication protocols specified in respective communication standards. Please note that the invention is not limited by this.

In one example, the UE 110 and the base station 120 are configured to deploy carrier aggregation (CA) or dual-connection (DC) techniques to enhance UE’s throughput.

When the system deploy the CA, it could have Master Cell Group (MCG) 130. The MCG 130 includes Pcell 131 and SCell 1 132 to SCell N 133.

When the system deploy the DC, it could have Master Cell Group (MCG) 130 and Secondary Cell Group (SCG) 140. The MCG 130 includes Pcell 131 and SCell 1 132 to SCell N 133. The SCG 140 includes PScell 141 and SCell 1 142 to SCell N 143.

Fig. 2 shows an example of multiple SCell activation procedure for intra-band mmWave 200 when none of the SCells being activated is known SCell. Both SCell 1 and SCell 2 are unknown SCell. The definition of known SCell is already captured in the specification and known to related engineer as follow.

For the first SCell activation in FR2 bands, the SCell is known if it has been meeting the following conditions:

-During the period equal to 4s for UE supporting power class1 and 3s for UE supporting power class 2/3/4 before UE receives the last activation command for PDCCH TCI, PDSCH TCI (when applicable) and semi-persistent CSI-RS for CQI reporting (when applicable) :

-the UE has sent a valid L3-RSRP measurement report with SSB index.

-SCell activation command is received after L3-RSRP reporting and no later than the time when UE receives MAC-CE command for TCI activation.

-During the period from L3-RSRP reporting to the valid CQI reporting, the reported SSBs with indexes remain detectable according to the cell identification conditions specified in clauses 9.2 and 9.3, and the TCI state is selected based on one of the latest reported SSB indexes.

Otherwise, the first SCell in FR2 band is unknown.

The Scell Activation Command Configuration of SCell 1 (210) can be the same as the Scell Activation Command Configuration of SCell 2 (2100) . The Scell activation command parsing &HARQ feedback of SCell 1 (220) can be the same procedure as the Scell 2 (2200) . The RF &AGC retuning of SCell 1 (230) can also be the same procedure as the Scell 2 (2300) .

Only one unknown SCell, such as SCell 1, needs to execute cell search (240) and L1-RSRP measurement &reporting (250) . Other unknown SCells, such as SCell 2, just hold on the activation procedure (2400) until one of the unknown SCell finishing the cell search and L1-RSRP measurement. After that all unknown SCells will wait their TCI configuration from network and execute their SCell activation process independently. For example, SCell 1 and SCell 2 can have their independent CSI-RS configuration, and reporting. It shall be noted that although the TCI configuration for QCL TypeD RS shall be the same source SSB, the TCI configuration for these unknown SCells shall still be different because each serving cell’s timing/Doppler configuration RS bases on its serving cell’s information independently. UE can also retune these unknown SCells’ RF at the same time. Therefore, there is no additional interruption needed in this scenario.

Fig. 3 shows an example of multiple SCell activation procedure for intra-band mmWave 300 when at least one of the SCells being activated is known SCell and one of the SCells being activated is unknown SCell. SCell 1 is known cell, and SCell 2 is unknown cell.

The Scell Activation Command Configuration of SCell 1 (310) can be the same as the Scell Activation Command Configuration of SCell 2 (3100) . The Scell activation command parsing &HARQ feedback of SCell 1 (330) can be the same procedure as the Scell 2 (3300) . The RF &AGC retuning of SCell 1 (340) can also be the same procedure as the Scell 2 (3400) .

The unknown SCell (SCell 2) won’t need cell search, L1-RSRP measurement and reporting procedure. SCell2 will wait PDCCH TCI, PDSCH TCI, CSI-RS reporting configuration and SCell activation command 3200. After that, the Unknown SCells will also have the same but independent activation procedure as known SCell 3300-3600. Owing to the TCI and CSI-RS configuration for each SCell may not come at the same time. The RF retuning occasion for each SCell shall also different, but as we discussed above, UE can schedule the RF retuning occasion to avoid the collision with SSB for timing tracking. Thus, no additional interruption is needed in this scenario.

Fig. 4 shows an example of multiple SCell activation procedure for inter-band mmWave 400. SCell 1 and SCell 2 are inter-band SCells. UE shall be allowed to use different Rx/Tx beams on 2 SCells at a time, but whether to use different/same Rx/Tx beams is up to UE implementation.

The Scell Activation Command Configuration of SCell 1 (410) can be the different as the Scell Activation Command Configuration of SCell 2 (4100) . The Scell activation command parsing &HARQ feedback of SCell 1 (420) can be the different procedure as the Scell 2 (4200) . The RF &AGC retuning of SCell 1 (430) can also be the different procedure as the Scell 2 (4300) .

A possible solution is that SCell 1 will execute cell search 440 and L1-RSRP measurement 450 at first. The SCell 2 will wait SCell 1 to finish the cell search and L1-RSRP measurement 4400. Then, SCell 2 will execute cell search 4500 and L1-RSRP measurement 4600. After that, the SCell 1 and SCell 2 will execute their SCell activation procedure independently.

Fig. 5 shows an exemplary block diagram of a UE 500 according to an embodiment of the disclosure. The UE 500 can be configured to implement various embodiments of the disclosure described herein. The UE 500 can include a processor 510, a memory 520, and a radio frequency (RF) module 1130 that are coupled together as shown in Fig. 5. In different examples, the UE 500 can be a mobile phone, a tablet computer, a desktop computer, a vehicle carried device, and the like.

The processor 510 can be configured to perform various functions of the UE 120 described above with reference to Figs. 1-4. The processor 510 can include signal processing circuitry to process received or to be transmitted data according to communication protocols specified in, for example, LTE and NR standards. Additionally, the processor 510 may execute program instructions, for example, stored in the memory 520, to perform functions related with different communication protocols. The processor 510 can be implemented with suitable hardware, software, or a combination thereof. For example, the processor 510 can be implemented with application specific integrated circuits (ASIC) , field programmable gate arrays (FPGA) , and the like, that includes circuitry. The circuitry can be configured to perform various functions of the processor 510.

In one example, the memory 520 can store program instructions that, when executed by the processor 510, cause the processor 510 to perform various functions as described herein. The memory 520 can include a read only memory (ROM) , a random access memory (RAM) , a flash memory, a solid state memory, a hard disk drive, and the like.

The RF module 530 can be configured to receive a digital signal from the processor 510 and accordingly transmit a signal to a base station in a wireless communication network via an antenna 540. In addition, the RF module 530 can be configured to receive a wireless signal from a base station and accordingly generate a digital signal which is provided to the processor 510. The RF module 530 can include digital to analog/analog to digital converters (DAC/ADC) , frequency down/up converters, filters, and amplifiers for reception and transmission operations. For example, the RF module 530 can include converter circuits, filter circuits, amplification circuits, and the like, for processing signals on different carriers or bandwidth parts.

The UE 500 can optionally include other components, such as input and output devices, additional CPU or signal processing circuitry, and the like. Accordingly, the UE 500 may be capable of performing other additional functions, such as executing application programs, and processing alternative communication protocols.

The processes and functions described herein can be implemented as a computer program which, when executed by one or more processors, can cause the one or more processors to perform the respective processes and functions. The computer program may be stored or distributed on a suitable medium, such as an optical storage medium or a solid-state medium supplied together with, or as part of, other hardware. The computer program may also be distributed in other forms, such as via the Internet or other wired or wireless telecommunication systems. For example, the computer program can be obtained and loaded into an apparatus, including obtaining the computer program through physical medium or distributed system, including, for example, from a server connected to the Internet.

The computer program may be accessible from a computer-readable medium providing program instructions for use by or in connection with a computer or any instruction execution system. A computer readable medium may include any apparatus that stores, communicates, propagates, or transports the computer program for use by or in connection with an instruction execution system, apparatus, or device. The computer-readable medium can be magnetic, optical, electronic, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. The computer-readable medium may include a computer-readable non-transitory storage medium such as a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM) , a read-only memory (ROM) , a magnetic disk and an optical disk, and the like. The computer-readable non-transitory storage medium can include all types of computer readable medium, including magnetic storage medium, optical storage medium, flash medium and solid state storage medium.

While aspects of the present disclosure have been described in conjunction with the specific embodiments thereof that are proposed as examples, alternatives, modifications, and variations to the examples may be made. Accordingly, embodiments as set forth herein are intended to be illustrative and not limiting. There are changes that may be made without departing from the scope of the claims set forth below.

Claims

A method of multiple SCell activation, comprising:

When all of the SCell are unknown SCells,

Only one of the SCell will execute cell search and L1-RSRP measurement and reporting,

Other SCells will wait the TCI and CSI-RS configuration from network, and

After that, all of the SCells will execute their SCell activation procedure independently.
A method of multiple SCell activation, comprising:

When at least one of the SCell is known SCell and at least one of the SCell is unknown SCell,

The known SCell will share the same prior information, such as timing, best beam information with unknown SCell. and

The unknown SCell activation procedure shall be the same as the known SCell.
A method of multiple SCell activation, comprising:

When the SCells are inter-band SCells,

All of the SCells can execute the L1-RSRP measurement at the same time.
A method of multiple SCell activation, comprising:

When the SCells are inter-band SCells,

All of the SCells can execute the L1-RSRP measurement sequentially.