CN112929893A

CN112929893A - Method and device for switching receiving wave beams

Info

Publication number: CN112929893A
Application number: CN201911244120.5A
Authority: CN
Inventors: 白瑞朋
Original assignee: Datang Mobile Communications Equipment Co Ltd
Current assignee: Datang Mobile Communications Equipment Co Ltd
Priority date: 2019-12-06
Filing date: 2019-12-06
Publication date: 2021-06-08

Abstract

The invention provides a method and a device for switching receiving beams. The method comprises the following steps: after a terminal accesses the base station, establishing a beam pair with the terminal; receiving a beam measurement result reported by the terminal; determining whether the reception beam satisfies a beam switching condition based on the beam measurement result and a beam reference signal reception power of a reception beam currently used in the beam pair; switching the receive beam on the basis that the receive beam in the beam pair remains unchanged, if it is determined that the receive beam satisfies a beam switching condition. The invention can make the wave beam select the best wave beam in real time along with the movement of the equipment or the change of the environment, increase the signal to noise ratio of useful signals and noise signals of a receiving end, improve the anti-interference characteristic of a channel and improve the reliability and the applicability of millimeter wave communication.

Description

Method and device for switching receiving wave beams

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a method and an apparatus for switching receive beams.

Background

Due to the shortage of communication frequency resources, in the current communication system, the frequency band below 3GHz (gigahertz) is difficult to be allocated to a continuously large bandwidth to increase the user peak rate, while the millimeter wave frequency band is relatively easy to be obtained and allocated to a continuously large bandwidth.

In China, in the system experiment of allocating 3.3-3.6GHz and 4.8-5.0GHz bands to low-frequency 5G (5th Generation Mobile Networks, fifth Generation Mobile communication technology) in the frequency band below 6GHz, two sections of millimeter wave bands of 24.75-27.5GHz and 37-42.5GHz are generally used as the high-frequency 5G technical experiment. The development of a high-frequency base station supporting an Enhanced Mobile Broadband (eMBB) scene can meet the increasing demand of people on communication bandwidth, and has practical significance. However, the millimeter wave transmission signal is greatly affected by the environment and has high loss.

Disclosure of Invention

The technical problem to be solved by the embodiments of the present invention is to provide a received beam switching method, a received beam switching method and a device, so as to solve the technical problems in the prior art that a millimeter wave transmission signal is greatly influenced by an environment and has high loss.

In order to solve the above technical problem, an embodiment of the present invention provides a method for switching receive beams, which is applied to a base station, and includes:

after a terminal accesses the base station, establishing a beam pair with the terminal;

receiving a beam measurement result reported by the terminal;

determining whether the reception beam satisfies a beam switching condition based on the beam measurement result and a beam reference signal reception power of a reception beam currently used in the beam pair;

switching the receive beam on the basis that the receive beam in the beam pair remains unchanged, if it is determined that the receive beam satisfies a beam switching condition.

Optionally, the receiving the beam measurement result reported by the terminal includes:

transmitting a measurement report for a layer-to-layer reference signal received power to the terminal;

receiving a measurement result reported by the terminal according to the measurement report; the measurement result includes a beam measurement result, which is obtained by the terminal scanning a beam used previously.

Optionally, the determining whether the receiving beam satisfies a beam switching condition based on the beam measurement result and the beam reference signal received power of the currently used receiving beam in the beam pair includes:

obtaining the maximum reference signal received power in the reference signal received powers of all the received beams in the beam measurement result;

calculating a difference between the maximum reference signal received power and the beam reference signal received power;

when the difference is larger than a set threshold, determining that the receiving wave beam meets a wave beam switching condition;

and when the difference is smaller than or equal to the set threshold, determining that the receiving beam does not meet the beam switching condition.

Optionally, after the receiving the beam measurement result reported by the terminal, the method further includes:

and when the beam measurement results received for the continuous preset times do not contain the beam reference signal receiving power of the currently used receiving beam, executing the operation of switching the receiving beam.

In order to solve the above technical problem, an embodiment of the present invention provides a method for switching receive beams, which is applied to a terminal and includes:

after accessing a base station, establishing a beam pair with the base station;

receiving a downlink reference signal sent by the base station;

measuring the downlink reference signal on a group of pre-configured receiving beams to obtain a measurement result;

determining whether the receiving beam satisfies a beam switching condition based on the measurement result and a beam reference signal received power of a receiving beam currently used by the terminal;

Optionally, the measuring the downlink reference signal on a group of pre-configured receive beams to obtain a measurement result includes:

measuring the downlink reference signals on the set of receiving beams, and determining the maximum reference signal receiving power in the reference signal receiving powers of the set of receiving beams;

In order to solve the above technical problem, an embodiment of the present invention provides a receive beam switching apparatus, applied to a base station, including:

a first beam pair establishing module, configured to establish a beam pair with a terminal after the terminal accesses the base station;

a beam measurement result receiving module, configured to receive a beam measurement result reported by the terminal;

a first beam switching condition determining module for determining whether the receiving beam satisfies a beam switching condition based on the beam measurement result and a beam reference signal received power of a currently used receiving beam in the beam pair;

and the receiving beam switching module is used for switching the receiving beam on the basis that the receiving beam in the beam pair is kept unchanged under the condition that the receiving beam is determined to meet the beam switching condition.

Optionally, the beam measurement result receiving module includes:

a measurement report sending submodule for sending a measurement report for a layer-to-layer reference signal received power to the terminal;

a measurement result receiving submodule for receiving the measurement result reported by the terminal according to the measurement report; the measurement result includes a beam measurement result, which is obtained by the terminal scanning a beam used previously.

Optionally, the first beam switching condition determining module includes:

a maximum power obtaining submodule for obtaining a maximum reference signal received power among reference signal received powers of all received beams in the beam measurement result;

a first difference calculation sub-module for calculating a difference between the maximum reference signal received power and the beam reference signal received power;

a first switching condition determining submodule, configured to determine that the received beam satisfies a beam switching condition when the difference is greater than a set threshold;

and the second switching condition determining submodule is used for determining that the receiving beam does not meet the beam switching condition when the difference value is smaller than or equal to the set threshold.

Optionally, the method further comprises:

and the beam switching operation execution module is used for executing the operation of switching the receiving beam when the beam measurement results received for the continuous preset times do not contain the beam reference signal receiving power of the currently used receiving beam.

In order to solve the above technical problem, an embodiment of the present invention provides a receive beam switching apparatus, which is applied to a terminal, and includes:

a second beam pair establishing module, configured to establish a beam pair with a base station after accessing the base station;

a downlink reference signal receiving module, configured to receive a downlink reference signal sent by the base station;

a measurement result obtaining module, configured to measure the downlink reference signal on a group of pre-configured receive beams, and obtain a measurement result;

a second beam switching condition determining module, configured to determine whether the receiving beam satisfies a beam switching condition based on the measurement result and a beam reference signal received power of a receiving beam currently used by the terminal;

Optionally, the second beam switching condition determining module includes:

a maximum power determination sub-module, configured to measure the downlink reference signal on the set of receive beams, and determine a maximum reference signal receive power of the reference signal receive powers of the set of receive beams;

a second difference calculation sub-module for calculating a difference between the maximum reference signal received power and the beam reference signal received power;

a third switching condition determining submodule, configured to determine that the received beam meets a beam switching condition when the difference is greater than a set threshold;

and the fourth switching condition determining submodule is used for determining that the receiving beam does not meet the beam switching condition when the difference value is smaller than or equal to the set threshold.

Compared with the prior art, the embodiment of the invention has the following advantages:

in the embodiment of the invention, the wave beam can select the optimal wave beam in real time along with the movement of equipment or the change of environment, the signal to noise ratio of useful signals and noise signals of a receiving end is increased, the anti-interference characteristic of a channel is improved, and the reliability and the applicability of millimeter wave communication are improved.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

Fig. 1 is a flowchart illustrating steps of a method for switching receive beams according to an embodiment of the present invention;

fig. 1a is a schematic diagram of an SSB frame structure according to an embodiment of the present invention;

FIG. 1b is a schematic diagram of an SS Burst structure according to an embodiment of the present invention;

fig. 1c is a schematic diagram of a receive beam adjustment according to an embodiment of the present invention;

fig. 2 is a flowchart illustrating a method for switching receive beams according to an embodiment of the present invention;

fig. 2a is a schematic diagram of a receive beam adjustment according to an embodiment of the present invention;

fig. 2b is a schematic diagram of a UE relative to a base station according to an embodiment of the present invention;

FIG. 2c is a schematic diagram of a simulation system according to an embodiment of the present invention;

fig. 2d is a schematic diagram of comparing channel SINR parameters for open beam management and wide beam according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a receive beam switching apparatus according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a receive beam switching apparatus according to an embodiment of the present invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the examples of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

In order to support non-line-of-sight transmission and high-reliability mobility, one of the methods is to adjust the gain of the transmit-receive beam to optimize the gain, and the uplink and downlink beams must be managed in real time and accurately, beam parameters are adjusted, beam alignment is ensured, and signals are transmitted with maximum gain and minimum loss.

The following description will be made of a reference signal for downlink beam management, which is commonly used.

Common reference signals for downlink beam management may include:

1) and (3) idle initial access: SSB (Single Side Band );

2) connection state: CSI-RS (downlink reference signal) or SSB.

1. Synchronization signal and PBCH block (SSB)

The Synchronization signal and PBCH block is composed of a primary Synchronization signal pss (primary Synchronization signal), a secondary Synchronization signal sss (secondary Synchronization signal) group, and a PBCH (Physical Broadcast Channel). Each synchronization signal has a duration of 1 symbol and a bandwidth of 127 subcarriers. The PBCH channel occupies 3 consecutive symbols discontinuously, and has a bandwidth of 240 subcarriers. The content of the central symbol part occupied by the PBCH channel is used to traverse the SSS, in particular as shown in fig. 1 a: SS Burst is a set of SSBs sent in a certain direction in a 5ms half subframe, and its meaning is shown in fig. 1 b: and completing one beam scanning in one SS Burst set period. That is, a beam scanning using SSB set is called SS Burst set, and the SS Burst sets a period (i.e., an SSB transmission period of a specific beam), Ts ═ 5, 10, 20, 40, 80, 120 (unit is millisecond). The maximum number of SSBs in each SS burst set is related to the frequency band, and the number of SSBs in the set can be up to 64 when the frequency band is higher than 6 GHz.

2. CSI-RS reference signals

Compared with the SSB, the 5G NR CSI-RS (Channel State Information-Reference Signal) Reference Signal can be used for not only measurement and reporting of a downlink Channel, but also beam management and acquisition and reporting of a downlink beam. Unlike the SSB acting in the initial access state, the CSI-RS is mainly used for RRM (Radio Resource Management) measurement and mobility support of a UE (User Equipment) in a connected state.

For a 5G system using a millimeter wave air interface technology, once a connection is established between a UE and a base station, the beam directivity between the UE and the base station needs to be periodically identified, so as to achieve beam alignment between two communication nodes. For the concerned CSI-RS, the communication quality of the link can be calculated by selecting a preset number of best beams among all available beams and obtaining the signal quality thereof for averaging. For a large range of spatial coverage, the reference signal overhead can be high if there are a large number of narrow beams and these beams all transmit CSI-RS. In this case, based on the location of the active UE, only sending CSI-RS in some beams is considered, which not only reduces the system overhead of CSI-RS, but also is beneficial to UE energy saving, i.e. based on the SSB measurement reported by the UE, the base station finds out a subset including all sending directions from all the sets of beams to determine on which beams CSI-RS can be sent, and the UE further performs measurement based on CSI-RS received on these beams and reports to the base station.

Regarding beam management, the 3GPP (3rd Generation Partnership Project) protocol also only gives a rough design solution for beam management of downlink and uplink channels on the high frequency band. Based on the method, the invention mainly researches the management of the downlink wave beams and the design realization of the downlink wave beams. The invention designs a downlink beam management scheme according to a 3GPP protocol, provides a beam management scheme thought for the further development of a high-frequency wireless access network, and provides the specific realization of downlink beam management.

The invention realizes that the wave beam can select the optimal wave beam in real time along with the movement of equipment or the change of environment, increases the signal-to-noise ratio of useful signals and noise signals of a receiving end, improves the anti-interference characteristic of a channel, and improves the reliability and the applicability of millimeter wave communication. The method can be used as a reference for research and development of a high-frequency millimeter wave base station or a reference for designing a beam management frame during system simulation.

The invention divides the beam adjustment into two independent steps:

(1) under the condition that the current receiving beam direction is unchanged, re-evaluating and adjusting the transmitting beam direction;

(2) under the condition that the current transmission beam direction is unchanged, the receiving beam direction is reevaluated and adjusted.

Generally, beam adjustment needs to be performed in both the downlink transmission direction and the uplink transmission direction, and only one direction needs to be adjusted in the case of supporting a beam pair, such as adjusting downlink transmission and reception beam pairs.

Specifically, the technical solutions of the embodiments of the present invention are described in detail below with reference to the following embodiments.

Example one

Referring to fig. 1, a flowchart illustrating steps of a receive beam switching method according to an embodiment of the present invention is shown, where the receive beam switching method may be applied to a base station, and specifically may include the following steps:

step 101: and after the terminal accesses the base station, establishing a beam pair with the terminal.

In the embodiment of the present invention, a base station, i.e. a public mobile communication base station, is an interface device for a mobile device to access the internet, and is also a form of a radio station, which is a radio transceiver station for information transmission between a mobile telephone terminal and a mobile communication switching center in a certain radio coverage area.

In the present invention, the base station may be any one of a macro base station, a micro base station, a repeater station, and the like, and specifically, the present invention may be determined according to an actual situation, and the embodiment of the present invention is not limited thereto.

The terminal may be a mobile terminal, such as a mobile electronic Device like a mobile phone and a PAD (Portable Android Device).

A wave beam (wave beam) refers to a shape formed on the surface of the earth by electromagnetic waves emitted from a satellite antenna.

The beam pair refers to a beam pair formed between a base station and a terminal, and specifically may include an uplink receive beam and a downlink receive beam, that is, the receive beams exist in pairs.

After the terminal accesses the base station, a beam pair with the terminal may be established, specifically, the initial beam establishing immediate device receives a downlink signal, initially accesses the network, and selects an appropriate beam pair while establishing a connection with the network. During the initial cell search, the device acquires the SSB. Within different downlink beams, there may be multiple SSBs transmitting in sequence. The random access opportunity corresponding to each SSB (each SSB corresponds to a different beam) is associated with the preamble, and in the subsequent uplink random access process, the base station can identify the downlink beam captured by the device. Thereby establishing an initial beam pair, i.e. a beam pair between the base station and the terminal.

After the connection is established, the device determines that the network will use the same transmission beam in the subsequent communication process, and uses the receiving beam of the acquisition SSB for downlink reception. In a similar way, the terminal uses the corresponding beam in the random access process to transmit the subsequent uplink data, and the base station uses the initially accessed beam to receive the subsequent uplink data.

After the terminal accesses the base station and establishes a beam pair with the terminal, step 102 is executed.

Step 102: and receiving the beam measurement result reported by the terminal.

The beam measurement result refers to a result obtained by the terminal scanning a previously used beam.

The description in connection with the downlink receive beam is as follows:

the downlink receive beam adjustment is aimed at optimizing network beam transmission. It is assumed at this time that the device side still uses the previous receive beam. The device measures a series of reference signals corresponding to different pairs of downlink beams. The transmissions in the different downlink beams need to be performed in sequence, i.e. beam scanning needs to be performed, so that beam measurements can be obtained.

The terminal reports the beam measurement result to the network, and based on the reported beam measurement result, the network can decide whether to adjust the currently used downlink receiving beam.

Note that this adjustment may not require the selection of a beam that the device has measured, e.g. the network may decide to transmit data using the beam direction between two reported beams, as shown in fig. 1 c. It is also noted that when making measurements to support receive beam adjustment, the device receive beam needs to be held constant in order to measure the different receive beams given the current receive beam is constant.

To support the beam measurement and reporting, a measurement reporting framework based on a specific reporting configuration is used, and a measurement report is sent to the terminal in advance to instruct the terminal to upload the beam measurement report.

In a preferred embodiment of the present invention, the step 102 may include:

substep A1: transmitting a measurement report for a layer-to-layer reference signal received power to the terminal;

substep A2: receiving a measurement result reported by the terminal according to the measurement report; the measurement result includes a beam measurement result, which is obtained by the terminal scanning a beam used previously.

In the embodiment of the present invention, the L1-RSRP (Layer One-Reference Signal Receive Power) measurement report is a measurement report for instructing the terminal to report the beam measurement result.

The measurement Reference Signal corresponding to the beam needs to be included in a NZP-CSI-RS (Non-Zero Power Channel State Information-Reference Signal resource) resource set, which may include a set of configured CSI-RSs or a set of SSBs. The beam management measurements are made on either the CSI-RS or the SSB.

The base station configures the UE with an L1-RSRP measurement report through RRC signaling in order to determine the beam direction of the UE. L1-RSRP belongs to one of CSI reporting, and in order to support beam management, the mm wave base station needs the UE to report the RSRP measurement result of the beam, and the beam measurement and reporting may be based on SSB or CSI-RS. When the report quality in the report setting is configured to be "CRI-RSRP" or "SSB-Index-RSRP", the beam measurement result marked as beam management is reported, at this time, the associated resource setting contains a plurality of CSI-RS resources or a plurality of SSBs, and the UE determines an optimal plurality of CRIs or SSBs for reporting according to the RSRP measurement of all the resources. The value range of the reported RSRP number is 1, 2 and 4.

After receiving the beam measurement result reported by the terminal, step 104 is executed.

Step 103: determining whether the receive beam satisfies a beam switching condition based on the beam measurement result and a beam reference signal received power of a currently used receive beam of the beam pair.

The beam measurement result reported by the terminal includes Reference Signal Received Power (RSRP) of a reception beam used before the terminal side.

After receiving the beam measurement result reported by the terminal, it may be determined whether the received beam satisfies the beam switching condition by combining the RSRP of the received beam used by the terminal before in the beam measurement result and the beam reference signal received power (i.e., beam RSRP) of the currently used received beam in the beam pair, and specifically, it is described in detail with reference to the following preferred embodiments.

In a preferred embodiment of the present invention, the step 103 may include:

substep B1: and acquiring the maximum reference signal received power in the reference signal received powers of all the received beams in the beam measurement result.

In the embodiment of the present invention, the maximum reference signal received power refers to the maximum RSRP among RSRPs of all received beams in the beam measurement result, i.e., the strongest beam among all received beams in the beam measurement result.

After the beam measurement result is obtained, according to the beam measurement result, the strongest receiving beam of all the receiving beams used by the terminal before may be obtained, and RSRP of the strongest receiving beam, that is, the maximum RSRP, may be obtained.

After the maximum reference signal received power among the reference signal received powers of all the reception beams in the beam measurement result is acquired, sub-step B2 is performed.

Substep B2: calculating a difference between the maximum reference signal received power and the beam reference signal received power.

The difference refers to the difference between the maximum RSRP and the beam RSRP.

After obtaining the maximum RSRP and the beam RSRP of the downlink receiving beam currently used by the terminal, a difference between the maximum RSRP and the beam RSRP may be calculated, and then, sub-step B3 is performed, or sub-step B4 is performed.

Substep B3: and when the difference is larger than a set threshold, determining that the receiving beam meets a beam switching condition.

The setting of the threshold refers to a threshold value preset by a service person, and a specific value of the setting of the threshold may be determined according to a service requirement, which is not limited in the embodiment of the present invention.

When the difference is greater than the set threshold, it can be determined that the receive beam satisfies the beam switching condition.

Substep B4: and when the difference is smaller than or equal to the set threshold, determining that the receiving beam does not meet the beam switching condition.

When the difference is less than or equal to the set threshold, it may be determined that the receive beam does not satisfy the beam switching condition.

After determining whether the reception beam satisfies the beam switching condition, step 104 is performed.

Step 104: switching the receive beam on the basis that the receive beam in the beam pair remains unchanged, if it is determined that the receive beam satisfies a beam switching condition.

When determining that the downlink receive beam satisfies the beam switching condition, the downlink receive beam at the base station side may be kept unchanged, and the downlink receive beam may be switched, specifically, the receive beam corresponding to the maximum RSRP may be used as the downlink receive beam of the base station, thereby completing the switching of the downlink receive beam.

According to the scheme, measurement is carried out on the basis of periodic CSI-RS signals, and UE periodically executes beam measurement and reports the beam measurement through PUCCH. The MAC maintains the current beam direction of the UE according to the reported value of the beam measurement, leads the direction of the corresponding SSB when the initial beam direction of the UE before receiving the measurement report is random access, and triggers the beam switching process when the difference value of the RSRP of the strongest beam and the current beam after receiving the measurement report is larger than a set threshold.

Additionally, in the present invention, when no beam RSRP of the terminal is included in the beam measurement results of the continuous reception, the beam switching operation may be performed, and specifically, the following detailed description is made in conjunction with the preferred embodiments.

In another preferred embodiment of the present invention, after the step 101, the method may further include:

substep C1: and when the beam measurement results received for the continuous preset times do not contain the beam reference signal receiving power of the currently used receiving beam, executing the operation of switching the receiving beam.

In the embodiment of the present invention, the preset number of times refers to a number of times for determining a reception beam measurement result, which is preset by a service person.

The preset times may be 3 times, 5 times, 8 times, and the like, and specifically may be determined according to a service requirement, and the embodiment of the present invention does not limit a specific numerical value of the preset times.

And when the beam measurement results received for the continuous preset times do not contain the RSRP of the currently used receiving beam at the terminal side, executing switching operation on the receiving beam.

When performing beam switching, a beam direction of a CSI-RS, which is used by the UE for CQI (Channel Quality Indicator)/RI (Rank Indication)/PMI (Precoding Matrix Indicator) reporting, is switched simultaneously with a beam direction of a PDSCH (Physical Downlink Shared Channel) of the UE, and always keeps consistent.

According to the scheme, the terminal can report the measurement values (four reference signals correspond to four beams) corresponding to four reference signals (CSI-RS or SSB) at one time, and each measurement report comprises the following steps:

(1) this report is indicative of the relevant reference signals (up to 4, one for each beam);

(2) measurement of the strongest beam L1-RSRP;

(3) the L1-RSRP difference of the three beams with respect to the strongest beam remains.

It can be understood that, in the above process, description is focused on the downlink receiving beam switching process, and the uplink receiving beam switching process is similar to the downlink receiving beam switching process, and details of this process are not repeated in the embodiment of the present invention.

The embodiment of the invention can realize that the receiving wave beam can select the optimal wave beam in real time along with the movement of equipment or the change of environment, and can improve the anti-interference characteristic of a channel.

In the method for switching received beams provided in the embodiments of the present invention, after a terminal accesses a base station, a beam pair with the terminal is established, a beam measurement result reported by the terminal is received, and on the basis of the beam measurement result and a beam reference signal received power of a currently used received beam in the beam pair, the received beam is switched on the basis that the received beam in the beam pair remains unchanged when it is determined that the received beam satisfies a beam switching condition. The embodiment of the invention can realize that the receiving wave beam selects the optimal wave beam in real time along with the movement of equipment or the change of environment, increases the signal-to-noise ratio of useful signals and noise signals of a receiving end, improves the anti-interference characteristic of a channel, and improves the reliability and the applicability of millimeter wave communication.

Example two

Referring to fig. 2, a flowchart illustrating steps of a method for switching a receive beam according to an embodiment of the present invention is shown, where the method for switching a receive beam may be applied to a terminal, and specifically may include the following steps:

step 201: after accessing a base station, a beam pair with the base station is established.

The embodiment of the invention can be applied to the scene of switching the receiving beams.

The receiving beams may include an uplink receiving beam and a downlink receiving beam, and the embodiment of the present invention focuses on the downlink receiving beam for the handover process of the receiving beams.

A base station, i.e. a public mobile communication base station, is an interface device for a mobile device to access the internet, and is a form of a radio station, which is a radio transceiver station for information transmission with a mobile phone terminal through a mobile communication switching center in a certain radio coverage area.

After the terminal accesses the base station and establishes a beam pair with the base station, step 202 is performed.

Step 202: and receiving a downlink reference signal sent by the base station.

The receive beam adjustment aims to find the best receive beam, with the proviso that the current transmit beam is used. To support this function, the device will configure a set of downlink reference signals that are transmitted in the downlink beam at the base station side that is currently providing service.

After receiving the downlink reference signal transmitted by the base station, step 203 is executed.

Step 203: and measuring the downlink reference signal on a group of pre-configured receiving beams to obtain a measuring result.

The measurement result refers to a result obtained by measuring the downlink reference signal according to a set of pre-configured receiving beams. As shown in fig. 2a, the terminal device performs receive beam scanning, and measures configured downlink reference signals on a set of receive beams in sequence, so that a measurement result can be obtained.

After the measurement result is acquired, step 203 is performed.

Step 204: determining whether the reception beam satisfies a beam switching condition based on the measurement result and a beam reference signal reception power of a reception beam currently used by the terminal.

The measurement results include the reference signal received power (i.e., RSRP) of a set of receive beams.

After the measurement result is obtained, whether the receive beam satisfies the beam switching condition may be determined according to the RSRP of the group of receive beams included in the measurement result and the beam RSRP of the receive beam currently used by the terminal, and in particular, detailed description may be given in conjunction with the following preferred embodiments.

In a preferred embodiment of the present invention, the step 204 may include:

substep D1: measuring the downlink reference signals on the group of receiving beams, and determining the maximum reference signal receiving power in the reference signal receiving powers of the group of receiving beams.

In the embodiment of the present invention, after measuring downlink reference signals on a group of receive beams, reference signal received powers (i.e., RSRPs) of the group of receive beams may be determined, and then a maximum RSRP of the group of RSRPs may be obtained.

After determining the maximum RSRP, sub-step D2 is performed.

Substep D2: calculating a difference between the maximum reference signal received power and the beam reference signal received power.

The difference value refers to a difference value between the maximum RSRP and the beam RSRP of the reception beam currently used by the terminal.

After the maximum RSRP is determined, the difference between the maximum RSRP and the beam RSRP may be calculated and sub-step D3 performed, or sub-step D4 performed.

Substep D3: and when the difference is larger than a set threshold, determining that the receiving beam meets a beam switching condition.

Substep D4: and when the difference is smaller than or equal to the set threshold, determining that the receiving beam does not meet the beam switching condition.

After determining whether the reception beam satisfies the beam switching condition, step 205 is performed.

Step 205: switching the receive beam on the basis that the receive beam in the beam pair remains unchanged, if it is determined that the receive beam satisfies a beam switching condition.

When it is determined that the receive beam satisfies the beam switching condition, the receive beam at the terminal side may be kept unchanged, and the receive beam may be switched, specifically, the receive beam corresponding to the maximum RSRP may be used as the receive beam of the terminal, so that the switch of the receive beam is completed.

The receive beam adjustment can adjust the same reporting configuration based on the receive beam. The difference is that the receive beam adjustment is implemented in the device itself, and no measurement is reported.

To support receive-side analog beamforming, different reference signals in a set of resources are transmitted in different symbols so that a receive beam can scan the set of reference signals. Meanwhile, the device should agree that different reference signals in this resource set are transmitted using the same spatial filter (i.e. the transmission beams on the network side are the same, the same below). Typically, a configured resource set contains a duplicate flag indicating whether the device can consider all reference signals in the resource set to be transmitted using the same filter. The repetition flag should be set for the set of resources used for receive beamforming.

The embodiment of the invention can realize that the receiving wave beam can select the optimal wave beam in real time along with the movement of equipment or the change of environment, thereby improving the anti-interference characteristic of a channel.

In the method for switching received beams provided in the embodiment of the present invention, after accessing a base station, a beam pair with the base station is established, a downlink reference signal sent by the base station is received, the downlink reference signal is measured on a group of pre-configured received beams, a measurement result is obtained, and based on the measurement result and a beam reference signal reception power of a received beam currently used by the terminal, the received beam is switched on the basis that the received beam in the beam pair remains unchanged when it is determined that the received beam satisfies a beam switching condition. The embodiment of the invention can realize that the receiving wave beam selects the optimal wave beam in real time along with the movement of equipment or the change of environment, increases the signal-to-noise ratio of useful signals and noise signals of a receiving end, improves the anti-interference characteristic of a channel, and improves the reliability and the applicability of millimeter wave communication.

In the above first and second embodiments of the method, the switching between the receive beam and the transmit beam is described in detail, and in the present invention, beam recovery can also be achieved.

1. Beam recovery

For the millimeter wave band, movement or other factors present in the environment may cause the established beam pair to become rapidly blocked and it is too late to perform normal beam adjustments to accommodate this change. The specified specification sets out a set of procedures called beam recovery to deal with this scenario, and the reasons for introducing the beam recovery procedure for handling beam failure are:

(1) beam failure is typically a rapid deterioration in the channel quality of an established beam pair resulting in a loss of connection, which is particularly evident for narrow beams. The beam Failure occurs more frequently than the Radio Link Failure (RLF), and the RLF corresponds to many scenarios in which the terminal moves out of the coverage of a certain cell, and the scenarios are different.

(2) RLF typically means that the terminal loses the signal of the current serving cell and must re-establish a connection in a new cell (which may also be the same as the previous serving cell), which may be different in frequency from the previous serving cell. After a beam failure occurs, a new beam pair is reestablished in the current cell so that the connection can be reestablished. The beam failure recovery is usually realized through a bottom layer function, and can be quickly recovered; while RLF is typically implemented by higher layer mechanisms, the recovery speed is relatively slow.

Typically the beam failure/recovery comprises the following steps:

(1) and (3) beam failure detection: the terminal detects that the beam failure occurs;

(2) candidate beam identification: the terminal attempts to identify a new beam, i.e. identifies a pair of beams that may restore the connection;

(3) and (3) recovery request transmission: the device transmits a beam recovery request to the network;

(4) the network responds to the beam recovery request.

Step 1: beam failure detection

When the PDCCH (Physical Downlink Control Channel) error probability exceeds a certain value, it can be considered that a beam failure occurs. Similar to radio link failure, the terminal device does not actually measure the error probability of the PDCCH, but measures the quality of some reference signals. The terminal measures a periodic CSI-RS of PDCCH quasi-parity or L1-RSRP of one SSB to determine whether a beam failure has occurred. The device should measure a reference signal (CSI-RS or SSB) related based on a PDCCH TCI (PDCCH Tag Control Information) state to determine whether a beam failure has occurred. The network may also configure a different CSI-RS with certainty, from which the terminal makes measurements to determine whether the beam has failed.

And if the LI-RSRP measured each time is lower than a configured threshold, a beam failure event occurs, and if the continuous beam failure events exceed a configured value, the beam failure occurs, and the subsequent beam recovery process is executed.

Step 2: new candidate beam identification

As a first step of the beam recovery procedure, the terminal tries to find a new set of beam pairs in order to recover the connection. To accomplish this, the terminal is configured with a set of resources that includes a set of CSI-RSs or a set of SSBs. Each of the set of resources is actually a signal transmitted on each particular downlink beam, such that each of the set of resources corresponds to a set of candidate beams.

As with conventional beam setup, the terminal device measures the L1-RSRP of the reference signal on the candidate beam, indicating that the corresponding beam may be used for recovery if its value exceeds some configured threshold. Note that when performing this operation, the terminal device must consider the different receive-side beam directions as much as possible, i.e., the terminal device actually determines a candidate beam pair.

Step 3: beam recovery request and response

If a beam failure occurs and a new beam pair is identified, the terminal performs a beam recovery request procedure. This procedure is used to inform the network that the device has detected a beam failure. The recovery request may contain candidate beams identified by the device.

The beam recovery request is essentially a contention-free random access procedure, including transmitting a preamble and receiving a random access response. Each reference signal corresponding to a different candidate beam is associated with a particular preamble configuration (RACH occasion and preamble sequence, etc.). For the identified beam, preamble transmission should be performed using the associated preamble configuration. The uplink beam used for preamble transmission should correspond to the identified downlink beam.

It should be noted that each candidate beam does not have to be associated with a unique preamble configuration, and there are the following candidate methods:

(1) each candidate beam is associated with a unique preamble configuration. In this case, the network can directly identify the corresponding downlink beam information from the received preamble information;

(2) the candidate beams are divided into different groups, all beams in the same group corresponding to the same preamble configuration, and beams in different groups corresponding to different preamble configurations. In this case, the received preamble only indicates the group to which the downlink beam is identified;

(3) all candidate beams are associated with the same preamble configuration. In this case, the preamble reception merely indicates that a beam failure has occurred, and the device needs to perform beam failure recovery.

Given that the candidate beams originate from the same site, the random access transmissions can be considered well time aligned when they arrive at the receiver. Since there may be large differences in the overall path loss for different candidate beam pairs, the configuration of the beam recovery request transmission should include a power ramping parameter. The terminal monitors the recovery request response at the beginning of four time slots after sending the recovery request. If no response is received within a configurable window of size, the device retransmits the beam recovery request according to the configured power ramp parameter.

And then combining the specific experimental result and analysis of the downlink wave beam.

1. PDCCH beam

The beam direction of the PDCCH is indicated by a tci (transmission Configuration indicator) state of the CORESET (physical resource). The TCI state of the PDCCH is not configured independently and can be selected from the TCI states of the PDSCH, the RRC configures M TCI states (M is a positive integer greater than or equal to 1) for the PDSCH through PDSCH-Config, and the PDCCH has 64 TCI states at most, namely the maximum value of M is 64. The UE has a plurality of CORESET at each bwp (bandwidth part), and each CORESET configures K TCI states selected from M TCI states. For each core set, the MAC-CE may activate one TCI state from K TCI states, and if K is 1, it is not necessary to activate a certain TCI state using the MAC-CE (control unit).

When the base station reports through beam measurement that the optimal transmitting beam of the UE changes, the beam directions of all CORESETs on the current BWP of the UE are modified into new beam directions through MAC-CE. And the MAC-CE can be repeatedly transmitted for multiple times in multiple continuous slots through the beam switching of the MAC-CE, so that the UE can be ensured to receive the MAC-CE.

After receiving the MAC-CE, the UE has a certain effective time delay, and it is to be ensured that the time when the base station switches to the new beam is as consistent as possible with the time when the UE switches to the new beam for reception. For a coverage scene, the sending opportunity of the MAC-CE switched by the beam can be placed at slots 5ms before the SSB is sent, the UE has no downlink service in the 5ms of the SSB, and the MAC-CE is waited to take effect in the 5 ms. After the SSB is finished, the new wave beam is directly switched to send the UE service, so that the inconsistency of the effective time can be avoided.

2. PDSCH beam

The RRC configures M TCI states for the PDSCH through PDSCH-Config, the maximum configuration of 128 states is supported in the protocol, and the number of the configurations depends on the UE capability. A maximum of 8 TCI states are selected by the MAC-CE. The number of TCI states that the UE can support for activating PDSCH needs to refer to UE capability and beam measurement report of the UE, and select activated TCI states for the UE, for example, if the UE supports activation of 8 TCI states, then select the most likely 8 used TCI states according to the beam measurement report of the UE in the latest period of time. DCI (downlink control information) indicates a PDSCH beam, selects the strongest beam as a PDSCH transmission beam according to a beam measurement report of the UE, and notifies the UE of the DCI information. And the PDSCH and the PDCCH special for the UE are scheduled in the same time slot, and the beam of the PDSCH is indicated by using the beam direction of the CORESET with the lowest CORESET-ID in the nearest slot containing the CORESET instead of using the DCI or the PDCCH for scheduling the DCI. If the base station detects that the optimal transmitting beam of the UE is changed, the beam of the PDCCH indicates the beam direction of the CORESET used for scheduling the PDCCH through the MAC-CE, so the beam of the PDSCH can be kept consistent with the PDCCH beam by modifying the beam direction of the CORESET, and the base station does not need to separately process 3, NS3 network simulation and verification for the beam change of the PDSCH

Fig. 2c shows that a high-frequency-band millimeter wave network system structure is built based on NS3 network simulation, and a downlink beam management scheme designed by the present invention is used in the simulation to determine the best signal path and enable the beam to select the best beam in real time along with the movement of the device or environmental changes to ensure the channel quality. The simulation basic scene settings are shown in table 1. The comparison of the channel SINR (Signal to Interference plus Noise Ratio) values output by simulation shows that the beam management can improve the communication quality.

Table 1:

in the simulation experiment, the relative position between the UE and the base station under the same environment is shown in fig. 2b, and the SINR parameters outputted under the scenarios of the wide beam and the on beam management function without using the beam management are shown in fig. 2d, respectively.

As shown in fig. 2d, when the UE moves at a speed of 1m/s, it can be seen that the SINR of the received desired signal and interference signal is about 20dbm when the UE does not use beam management for transmitting and receiving signals, which results in poor transmission and low efficiency. But under the condition of using the beam management function, the SINR value is on a 50dbm horizontal line, the channel quality performance is obviously improved, and the transmission efficiency is further improved.

EXAMPLE III

Referring to fig. 3, a schematic structural diagram of a receive beam switching apparatus according to an embodiment of the present invention is shown, where the receive beam switching apparatus may be applied to a base station, and specifically includes the following modules:

a first beam pair establishing module 310, configured to establish a beam pair with a terminal after the terminal accesses the base station;

a beam measurement result receiving module 320, configured to receive a beam measurement result reported by the terminal;

a first beam switching condition determining module 330, configured to determine whether the receiving beam satisfies a beam switching condition based on the beam measurement result and a beam reference signal received power of a currently used receiving beam in the beam pair;

a receive beam switching module 340, configured to switch the receive beam on the basis that the receive beam in the beam pair remains unchanged, if it is determined that the receive beam satisfies the beam switching condition.

Optionally, the beam measurement result receiving module 320 includes:

Optionally, the first beam switching condition determining module 330 includes:

Optionally, the method further comprises:

The receiving beam switching device provided in the embodiment of the present invention establishes a beam pair with a terminal after the terminal accesses a base station, receives a beam measurement result reported by the terminal, and switches a receiving beam on the basis that the receiving beam in the beam pair remains unchanged when it is determined that the receiving beam satisfies a beam switching condition based on the beam measurement result and a beam reference signal receiving power of the receiving beam currently used in the beam pair. The embodiment of the invention can realize that the receiving wave beam selects the optimal wave beam in real time along with the movement of equipment or the change of environment, increases the signal-to-noise ratio of useful signals and noise signals of a receiving end, improves the anti-interference characteristic of a channel, and improves the reliability and the applicability of millimeter wave communication.

Example four

Referring to fig. 4, a schematic structural diagram of a receive beam switching apparatus according to an embodiment of the present invention is shown, where the receive beam switching apparatus may be applied to a base station, and specifically includes the following modules:

a second beam pair establishing module 410, configured to establish a beam pair with a base station after accessing the base station;

a downlink reference signal receiving module 420, configured to receive a downlink reference signal sent by the base station;

a measurement result obtaining module 430, configured to measure the downlink reference signal on a group of pre-configured receive beams, so as to obtain a measurement result;

a second beam switching condition determining module 440, configured to determine whether the receiving beam satisfies a beam switching condition based on the measurement result and a beam reference signal received power of a receiving beam currently used by the terminal;

a receive beam switching module 450, configured to switch the receive beam on the basis that the receive beam in the beam pair remains unchanged, if it is determined that the receive beam satisfies the beam switching condition.

Optionally, the second beam switching condition determining module 440 includes:

The receiving beam switching device provided in the embodiment of the present invention establishes a beam pair with a base station after accessing the base station, receives a downlink reference signal sent by the base station, measures the downlink reference signal on a group of receiving beams configured in advance, obtains a measurement result, and switches the receiving beam on the basis that the receiving beam in the beam pair remains unchanged when it is determined that the receiving beam satisfies a beam switching condition based on the measurement result and the beam reference signal receiving power of the receiving beam currently used by the terminal. The embodiment of the invention can realize that the receiving wave beam selects the optimal wave beam in real time along with the movement of equipment or the change of environment, increases the signal-to-noise ratio of useful signals and noise signals of a receiving end, improves the anti-interference characteristic of a channel, and improves the reliability and the applicability of millimeter wave communication.

The embodiments in the present specification are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, apparatus, or computer program product. Accordingly, embodiments of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, embodiments of the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

Embodiments of the present invention are described with reference to flowchart illustrations and/or block diagrams of methods, terminals (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing terminal to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing terminal to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

While preferred embodiments of the present invention have been described, additional variations and modifications of these embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. Therefore, it is intended that the appended claims be interpreted as including preferred embodiments and all such alterations and modifications as fall within the scope of the embodiments of the invention.

Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or terminal that comprises the element.

The foregoing describes in detail a method and a device for switching receive beams according to the present invention, and the present invention applies specific examples to explain the principles and embodiments of the present invention, and the descriptions of the above examples are only used to help understand the method and the core ideas of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

1. A method for switching receiving beams is applied to a base station, and is characterized by comprising the following steps:

receiving a beam measurement result reported by the terminal;

2. The method of claim 1, wherein the receiving the beam measurement reported by the terminal comprises:

3. The method of claim 1, wherein the determining whether the receiving beam satisfies a beam switching condition based on the beam measurement result and a beam reference signal received power of a currently used receiving beam of the beam pair comprises:

4. The method of claim 1, wherein after the receiving the beam measurement reported by the terminal, further comprising:

5. A method for switching receiving beams is applied to a terminal, and is characterized by comprising the following steps:

after accessing a base station, establishing a beam pair with the base station;

receiving a downlink reference signal sent by the base station;

6. The method of claim 5, wherein the measuring the downlink reference signal on a pre-configured set of receiving beams to obtain a measurement result comprises:

7. A receiving beam switching device applied to a base station, comprising:

8. The apparatus of claim 7, wherein the beam measurement receiving module comprises:

9. The apparatus of claim 7, wherein the first beam switching condition determining module comprises:

10. The apparatus of claim 7, further comprising:

11. A receiving beam switching device applied to a terminal, comprising:

12. The apparatus of claim 11, wherein the second beam switching condition determining module comprises: