CN116866935A

CN116866935A - Auxiliary network beam pre-switching method for 6G intelligent reflecting surface

Info

Publication number: CN116866935A
Application number: CN202310871446.0A
Authority: CN
Inventors: 张鸿涛; 张博广; 云翔
Original assignee: Beijing University of Posts and Telecommunications
Current assignee: Beijing University of Posts and Telecommunications
Priority date: 2023-07-14
Filing date: 2023-07-14
Publication date: 2023-10-10

Abstract

The application relates to a 6G intelligent reflection surface (RIS) auxiliary network beam pre-switching method, which relates to the field of wireless communication networks, in particular to a network planning tool. The application aims to execute beam switching for the affected service beam in advance before RIS reflection angle adjustment, or delete the beam in a candidate beam set, so that the influence of RIS reflection angle adjustment on all beams is minimized, the beam failure recovery process is reduced, and the communication efficiency is improved. The application is realized by the following steps: first, the base station configuring the RIS notifies all base stations using the RIS. These base stations then evaluate the affected beams and terminals, send signaling to the terminals indicating beam switching or deletion, and send acknowledgement messages to the base stations configuring the RIS. And finally, after the base station configuring the RIS waits for the feedback ACK or overtime, the RIS phase adjustment is carried out, and the terminal executes RIS mode switching according to the signaling instruction. Such RIS-based pre-scheduled beam switching may effectively utilize RIS resources.

Description

Auxiliary network beam pre-switching method for 6G intelligent reflecting surface

Technical Field

The application relates to the field of wireless communication networks, in particular to a network planning tool and a 6G intelligent reflector auxiliary network beam pre-switching method.

Background

In recent years, with the rapid development of intelligent super surface (Reconfigurable Intelligent Surface, RIS) technology, the academic world is actively exploring the performance of actual deployment of RIS to solve the coverage problem of 5G millimeter waves. Under the communication scene that the direct path from the base station to the terminal is blocked, the addition of RIS can make the network obtain significant capacity gain. However, each time the angle of the RIS reflection changes, all beams using the RIS are adjusted, potentially resulting in beam failure for the user.

Therefore, the patent designs a 6G intelligent reflection surface auxiliary network beam pre-switching method, before RIS reflection angle adjustment, beam switching is performed for the affected beams in advance, or the beams are deleted from a candidate beam set, so that the influence of RIS reflection angle adjustment on all beams is reduced to the minimum, the beam failure recovery process is reduced, and the communication efficiency is improved.

Disclosure of Invention

The following two scenes are classified according to different RIS placement positions:

scene one: the RIS is placed at the cell edge to enhance coverage for the users at the cell edge. As shown on the left side of fig. 1, a plurality of base stations share one RIS, and the RIS reflection angle is dynamically changed by one base station, which becomes the base station configuring the RIS. When the RIS angle changes, it affects users served by multiple base stations. For example, base station 1 serves User Equipment (UE) 1, base station 2 serves UE2, and when the RIS angle changes, the beam of UE2 is affected.

Scene II: RIS is placed in the middle of the cell to make blind for the specific area in the cell. As shown in the right side of fig. 1, a single base station covers different areas at different time points, and an RIS reflection angle switching situation also occurs, and a terminal originally served during the switching is affected. For example, if there are more users in the first daytime area and more users in the second nighttime area, the user of the RIS in the first daytime service area and the user in the second blackout service area may be affected by the user of the original RIS coverage area during the switching of the areas.

The 6G intelligent reflecting surface auxiliary network beam pre-switching method comprises the following steps:

step 200, the base station configuring the RIS notifies all base stations using the RIS.

Before the RIS phase configuration is modified, the base station configuring the RIS signals all base stations using the RIS that the RIS is to perform a phase adjustment operation.

Step 210, evaluate the affected beams and terminals, send signaling to the terminals to indicate beam switching or deletion, and send acknowledgement messages to the base station configuring the RIS.

After receiving the first signaling, the base station using the RIS evaluates the affected beam pairs according to the RIS number and the target RIS mode, and screens the affected terminals.

If the beam is the current service beam, beam switching is needed, and the affected terminal is indicated to fail through signaling II; if the beam is not the current serving beam, but is among the set of candidate beams, the beam is deleted from the set of candidate beams; if the beam is neither the current serving beam nor in the candidate set of beams, no action is taken.

After the base station using the RIS transmits the second signaling to the terminal, the base station configuring the RIS transmits the third signaling capable of performing phase adjustment after a period of time.

Step 220, the base station configuring RIS performs RIS phase adjustment after waiting for feedback ACK or overtime, and the terminal performs RIS mode switching according to the signaling instruction.

After receiving the second signaling, the UE executes RIS mode switching according to the target RIS mode in the signaling.

And the base station configuring the RIS receives more than half of ACK or performs the phase adjustment of the RIS after a period of time from the signaling transmission.

The signaling used in the above steps includes:

signaling one: a base station configuring an RIS transmits an RIS phase adjustment request message to a base station using the RIS, the message including the following fields:

RIS number: for identifying the RIS that needs to be phased.

Target RIS mode: for indicating the beam direction to which the RIS is to be switched.

Signaling II: the base station using the RIS evaluates the affected beam pair and the terminal according to the received RIS phase adjustment request message, and sends an RIS mode switching indication message to the affected terminal through the PDCCH, wherein the message comprises the following fields:

RIS number: a RIS for identifying the need to switch modes.

Target RIS mode: for indicating the beam direction to which the terminal is to be switched.

Signaling three: after all the RIS mode switching indication messages are sent, the base station using the RIS sends an RIS phase adjustment confirmation message to the base station configuring the RIS, wherein the message comprises the following fields:

RIS number: RIS for identifying that a mode switch indication has been completed.

ACK/NACK: for indicating whether a mode switch indication message has been successfully transmitted to all affected terminals.

Drawings

FIG. 1 is a scene graph of the present application;

FIG. 2 is a flow chart of an implementation of the present application;

Detailed Description

In order to make the technical problems, technical solutions and advantages to be solved more apparent, the following detailed description will be given with reference to the accompanying drawings and specific embodiments. In the following description, specific details such as specific configurations and components are provided merely to facilitate a thorough understanding of embodiments of the application. It will therefore be apparent to those skilled in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the application. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

In various embodiments of the present application, it should be understood that the sequence numbers of the following processes do not mean the order of execution, and the order of execution of the processes should be determined by the functions and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

It should be understood that the term "and/or" is merely an association relationship describing the associated object, and means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In the embodiments provided herein, it should be understood that "B corresponding to a" means that B is associated with a from which B may be determined. It should also be understood that determining B from a does not mean determining B from a alone, but may also determine B from a and/or other information.

The application provides a RIS phase configuration method and a RIS phase configuration system, which can reduce the influence on a base station and a terminal using the RIS when the RIS phase configuration is modified. The application is described in detail below with reference to the drawings and the detailed description.

FIG. 2 is a flow chart of a RIS phase configuration method of the present application. As shown in fig. 2, the method comprises the steps of:

step 300, before the RIS phase configuration is modified, the base station configuring the RIS signals to all base stations using the RIS that the RIS is about to perform a phase adjustment operation. The signaling one includes an RIS number and a target RIS pattern for identifying the RIS to which the phase needs to be adjusted and indicating the beam direction to which the RIS is to be switched.

Step 310, after receiving the first signaling, the base station using the RIS evaluates the affected beam pairs according to the RIS number and the target RIS pattern, and screens the affected terminals. The affected beam pair refers to a beam pair used when communication is performed between a base station and a terminal through the RIS using the RIS. An affected terminal refers to a terminal that communicates using an affected beam pair. If the beam is the current service beam, beam switching is needed, and the affected terminal is indicated to fail through signaling II; if the beam is not the current serving beam, but is among the set of candidate beams, the beam is deleted from the set of candidate beams; if the beam is neither the current serving beam nor in the candidate set of beams, no action is taken. The second signaling includes an RIS number and a target RIS mode for indicating the beam direction to which the terminal is to be switched. After the base station using the RIS transmits the second signaling to the terminal, the base station configuring the RIS transmits the third signaling capable of performing phase adjustment after a period of time. The signaling III includes RIS number and ACK/NACK for indicating RIS that has completed the mode switch indication and whether the mode switch indication message is successfully transmitted to all affected terminals.

Step 320, after receiving the second signaling, the ue performs RIS mode switching according to the target RIS mode in the signaling. I.e., selecting a matching receive/transmit beam according to the target RIS mode and communicating with the base station using the RIS. And the base station configuring the RIS receives more than half of ACK or performs the phase adjustment of the RIS after a period of time from the signaling transmission. Namely, sending a phase configuration signal to the RIS according to the target RIS mode, and controlling each adjustable phase unit to adjust the phase of the adjustable phase unit according to the phase configuration signal.

The following describes an embodiment of the present application with a specific example. Suppose that there is one base station 10 configuring the RIS and three base stations 20 using the RIS, denoted BS1, BS2 and BS3, respectively. BS1 may phase configure RIS40, while BS2 and BS3 may only communicate through RIS40, but not. Three terminals 30 are assumed, denoted UE1, UE2 and UE3, respectively. The UE1 and the BS1 communicate with each other through the RIS40, the UE2 and the BS2 communicate with each other through the RIS40, and the UE3 and the BS3 directly communicate with each other. It is assumed that there are two modes of RIS40, denoted M1 and M2, respectively, corresponding to different beam directions.

At some point, BS1 needs to switch RIS40 from mode M1 to mode M2 to improve communication performance or save power consumption. At this time, BS1 performs the following steps:

BS1 signals BS2 and BS3 that RIS40 is about to perform a phase adjustment operation and indicates that the target RIS mode is M2.

After receiving the signaling one, BS2 evaluates the affected beam pairs according to the RIS number and the target RIS pattern and screens the affected terminals. Since communication is performed between UE2 and BS2 through RIS40 and RIS40 is about to switch modes, UE2 is an affected terminal. BS2 needs to perform beam switching and indicates to UE2 through signaling two that the beam is about to fail and switch to a new beam matching the target RIS pattern.

After receiving the signaling one, BS3 evaluates the affected beam pairs according to the RIS number and the target RIS pattern and screens the affected terminals. Since communication is directly performed between the UE3 and the BS3 and does not pass through the RIS40, the UE3 is not an affected terminal. BS3 does not need to perform any operation.

After the BS2 transmits the second signaling to the UE2, the BS1 transmits the third signaling that can be phase-adjusted after a certain period of time.

After receiving the second signaling, UE2 performs RIS mode switching according to the target RIS mode M2 in the signaling. I.e., selects a reception/transmission beam matching the target RIS mode and communicates with BS 2.

BS1 receives more than half of the ACKs (i.e., ACKs from BS 2), or performs the phase adjustment of the RIS after a period of time (say 5 seconds) from the signaling transmission. I.e. to send a phase configuration signal to the RIS40 according to the target RIS mode M2 to adjust the RIS phase.

Through the steps, the application can reduce the influence on the base station and the terminal using the RIS when the RIS phase configuration is modified, and improve the communication efficiency and the quality.

While the foregoing is directed to the preferred embodiments of the present application, it will be appreciated by those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present application, and such modifications and adaptations are intended to be comprehended within the scope of the present application.

Claims

1. The 6G intelligent reflection surface assisted network beam pre-switching method is characterized by comprising the following steps of: before the RIS phase configuration is modified, the base station configuring the RIS informs all base stations using the RIS by signaling that the RIS is about to perform a phase adjustment operation; after receiving the first signaling, the base station using the RIS evaluates the affected beam pairs according to the RIS number and the target RIS mode, and screens the affected terminals; if the beam is the current service beam, beam pre-switching is needed, and the affected terminal is indicated by signaling II that the beam is about to fail, if the beam is not the current service beam but is in the candidate beam set, the beam is deleted from the candidate beam set, and if the beam is neither the current service beam nor the candidate beam set, no operation is performed; after the base station using RIS sends signaling II to the terminal, after a period of time, signaling III capable of carrying out phase adjustment is sent to the base station configuring RIS; after receiving the second signaling, the UE executes RIS mode switching according to the target RIS mode in the signaling; and the base station configuring the RIS receives more than half of ACK or performs the phase adjustment of the RIS after a period of time from the signaling transmission.

2. The wireless communication method of claim 1, wherein signaling one is an RIS phase adjustment request message sent by a base station configuring an RIS to a base station using the RIS, the message including an RIS number for identifying a beam direction to which the phase RIS needs to be adjusted, and a target RIS mode for indicating a beam direction to which the RIS is to be switched.

3. The method of claim 1, wherein if a pre-beam switch is required, the base station using the RIS selects an optimal beam from the candidate beam set as a new serving beam and indicates the affected terminal to switch to the new serving beam by signaling two.

4. A radio communication method according to claim 1 or 3, characterized in that signaling two is that the base station using the RIS evaluates the affected beam pair and the terminal according to the received RIS phase adjustment request message and sends an RIS mode switch indication message to the affected terminal via PDCCH, the message containing an RIS number for identifying the RIS to be phase adjusted and a target RIS mode for indicating the beam direction to which the RIS is to be switched.

5. The wireless communication method according to claim 1, wherein when the base station configuring the RIS performs the phase adjustment of the RIS, the phase adjustment of the RIS is performed according to the number of three ACKs signaled to the base station using the RIS or according to an interval of time.

6. The wireless communication method according to claim 1 or 5, wherein the signaling three is an RIS phase adjustment confirmation message transmitted to the base station configuring the RIS after all the RIS mode switch indication messages are transmitted using the base station of the RIS, the message including an RIS number for identifying that the mode switch indication RIS has been completed and ACK or NACK information for indicating whether the mode switch indication message has been successfully transmitted to all the affected terminals.