TECHNICAL FIELD

This application relates to communications technologies, and in particular, to a measurement method, a terminal device, and an access network device.

BACKGROUND

In a Long Term Evolution (Long Term Evolution, LTE for short) system, a terminal device performs radio resource management (Radio Resource Management, RRM for short) measurement based on a reference signal (Reference Signal, RS for short). If quality of a serving cell of the terminal device reaches a threshold, the terminal device stops measuring an intra-frequency neighboring cell to save power. If quality of a serving cell is lower than a threshold, the terminal device starts measuring an intra-frequency neighboring cell, to find a better intra-frequency neighboring cell. However, in the prior art, when calculating cell quality, a terminal device detects beams of a cell based on a quantity N of beams that need to be measured and that are specified by a network side, and detects a quantity M of beams whose signal quality exceeds a threshold. If M is greater than N, quality of N beams with best quality is averaged to obtain the cell quality. If M is less than N, quality of the M beams is averaged to obtain the cell quality. Cell quality obtained by averaging beam quality is inaccurate.

In a 5th generation mobile communications (5th-Generation, 5G for short) system, a terminal device does not perform RRM measurement based on an RS any more, but performs RRM measurement based on a synchronization signal (Synchronization Signal, SS for short). However, in the prior art, there is no specific implementation of measurement based on a synchronization signal.

SUMMARY

This application provides a measurement method, a terminal device, and an access network device, so as to make measurement of cell signal quality more accurate.

A first aspect of this application provides a measurement method, including: measuring, by a terminal device, signal quality of a plurality of beams, where the signal quality of the plurality of beams is obtained by using synchronization signal blocks, the signal quality of the plurality of beams includes signal quality of a same beam at different moments, and the plurality of beams belong to one cell; and obtaining signal quality of the cell based on the signal quality of the plurality of beams. In this way, cell measurement based on a synchronization signal is implemented, and the signal quality of the cell obtained based on the signal quality of the plurality of beams at the different moments is more accurate.

In a possible implementation, at least one piece of signal quality of one beam in the signal quality of the plurality of beams is obtained by using a synchronization signal block of the beam.

In a possible implementation, the obtaining, by the terminal device, signal quality of the cell based on the signal quality of the plurality of beams is specifically: separately performing, by the terminal device, filtering processing on the signal quality of the plurality of beams; and obtaining the signal quality of the cell based on filtered signal quality of the plurality of beams.

In a possible implementation, the method further includes: measuring, by the terminal device, only some beams of the cell when the signal quality of the cell exceeds a second quality threshold. In other words, remaining beams are no longer measured. Because only some beams of the cell are measured, power consumption of the terminal device is reduced.

In this specification, “exceed” means “greater than” or “greater than or equal to”.

In a possible implementation, the method further includes: obtaining, by the terminal device, a synchronization signal burst set sending period of the cell, where the synchronization signal burst set sending period includes one or more synchronization signal bursts, and there is a time interval between adjacent synchronization signal bursts. Usually, there is a time interval between adjacent synchronization signal bursts in the synchronization signal burst set sending period, each synchronization signal burst may include a plurality of synchronization signal blocks, and each synchronization signal block is sent on one beam. The synchronization signal burst set sending period may also be referred to as a synchronous signal burst set periodicity. Correspondingly, the measuring, by a terminal device, signal quality of a plurality of beams is specifically: detecting, by the terminal device within at least two synchronization signal burst set sending periods, synchronization signal blocks that are sent by an access network device on the plurality of beams, to obtain the signal quality of the plurality of beams; and determining that beam signal quality detected on synchronization signal blocks at a same corresponding position in the at least two synchronization signal burst set sending periods belongs to a same beam.

In a possible implementation, the method further includes: obtaining, by the terminal device, synchronization signal burst configuration information, where if the synchronization signal burst configuration information includes a quantity of synchronization signal bursts included in the synchronization signal burst set sending period, and a length and a starting position of a synchronization signal burst, the detecting, by the terminal device within at least two synchronization signal burst set sending periods, synchronization signal blocks that are sent by an access network device on the beams, to obtain the signal quality of the plurality of beams is specifically: detecting, by the terminal device in synchronization signal bursts of the at least two synchronization signal burst set sending periods based on the synchronization signal burst configuration information, the synchronization signal blocks that are sent by the access network device on the plurality of beams, to obtain the signal quality of the beams.

In a possible implementation, the method further includes: obtaining, by the terminal device, a synchronization signal burst set sending period of the cell, where the synchronization signal burst set sending period includes one or more synchronization signal bursts. There is a time interval between adjacent synchronization signal bursts, each synchronization signal burst includes one or more synchronization signal blocks, and each synchronization signal block is sent on one beam. Correspondingly, the measuring, by a terminal device, signal quality of a plurality of beams is specifically: detecting, by the terminal device within the synchronization signal burst set sending period, synchronization signal blocks that are sent by an access network device on the plurality of beams, to obtain the signal quality of the plurality of beams; determining, based on a beam timing index included in each received synchronization signal block, an identifier of a beam on which each synchronization signal block is sent; and determining that signal quality of beams having a same identifier belongs to a same beam.

In a possible implementation, the determining, by the terminal device based on a beam timing index included in each received synchronization signal block, an identifier of a beam on which each synchronization signal block is sent is specifically: performing, by the terminal device, a modulo operation on the beam timing index included in each synchronization signal block and the synchronization signal burst set sending period, to obtain the identifier of the beam on which each synchronization signal block is sent; or determining, by the terminal device, that the beam timing index included in each synchronization signal block is the identifier of the beam on which each synchronization signal block is sent.

In a possible implementation, the method further includes: measuring, by the terminal device, a neighboring cell of the cell, to obtain signal quality of the neighboring cell; determining an identifier of a to-be-reported beam from a plurality of beams of the neighboring cell, and/or determining an identifier of a to-be-reported beam from the plurality of beams of the cell; and sending the signal quality of the neighboring cell, the signal quality of the cell, and the identifier of the to-be-reported beam of the cell and/or the identifier of the to-be-reported beam of the neighboring cell to an access network device. In this way, the access network device performs neighboring cell handover based on the identifier of the to-be-reported beam, thereby increasing a success rate of neighboring cell handover.

In a possible implementation, the determining, by the terminal device, an identifier of a to-be-reported beam from beams of the neighboring cell, and/or determining an identifier of a to-be-reported beam from the beams of the cell is specifically: determining, by the terminal device, a beam whose filtered signal quality is greater than or equal to a preset third quality threshold as a to-be-reported beam based on the filtered signal quality of the beams of the cell, and/or determining, by the terminal device, a beam whose filtered signal quality is greater than or equal to the third quality threshold as a to-be-reported beam based on filtered signal quality of the beams of the neighboring cell; or determining, by the terminal device, N1beams whose signal quality is the best from the plurality of beams of the cell as to-be-reported beams based on a beam reporting quantity N1configured by the access network device, and/or determining, by the terminal device, N1beams whose signal quality is the best from the plurality of beams of the neighboring cell as to-be-reported beams.

In a possible implementation, the obtaining, by the terminal device, the signal quality of the cell based on filtered signal quality of the plurality of beams is specifically:

selecting, by the terminal device, B beams whose filtered signal quality is the best from the plurality of beams, where B is greater than or equal to 1 and is less than or equal to N, and N is a beam quantity threshold and is greater than or equal to 1;

adding up, by the terminal device, the filtered signal quality of the B beams, to obtain a signal quality sum; and

determining the signal quality of the cell based on the signal quality sum.

In a possible implementation, the selecting, by the terminal device, B beams whose filtered signal quality is the best from the plurality of beams is specifically:

selecting, by the terminal device, M beams whose signal quality is greater than a third quality threshold from the plurality of beams based on the filtered signal quality of the plurality of beams; and

when M is greater than N and B is equal to N, selecting, by the terminal device, N beams from the M beams; or

when M is less than N and B is equal to M, determining, by the terminal device, that the M beams are beams whose filtered signal quality is the best.

In a possible implementation, the determining the signal quality of the cell based on the signal quality sum is specifically:

determining, by the terminal device, the signal quality sum as the signal quality of the cell; or

determining, by the terminal device, a ratio of the signal quality sum to N as the signal quality of the cell; or

determining, by the terminal device, a ratio of the signal quality sum to B as the signal quality of the cell.

In a possible implementation, the measuring, by the terminal device, only some beams of the cell is specifically: measuring, by the terminal device, only synchronization signal blocks that are sent on B beams whose filtered signal quality is the best in the cell, where B is greater than or equal to 1 and is less than or equal to N, and N is a beam quantity threshold and is greater than or equal to 1; or measuring, by the terminal device, only a synchronization signal burst in which the synchronization signal blocks sent on the B beams are located. In other words, remaining beams are no longer measured.

In a possible implementation, the measuring, by the terminal device, only some beams of the cell is specifically: measuring, by the terminal device, only a synchronization signal block that is sent on a beam whose filtered signal quality is the best in the cell; or measuring, by the terminal device, only a synchronization signal burst in which a synchronization signal block sent on a beam whose filtered signal quality is the best is located.

A second aspect of this application provides a beam measurement method, including: sending, by an access network device, synchronization signal blocks on a plurality of beams of a cell; sending a message to a terminal device, where the message indicates a quantity of to-be-reported beams or at least one quality threshold of a to-be-reported beam of the terminal device, and the at least one quality threshold is used for beam measurement; and receiving, by the access network device, signal quality of the cell from the terminal device or an identifier that is of a to-be-reported beam of the cell and that is sent by the terminal device, where the signal quality of the cell is obtained by using the synchronization signal blocks.

In a possible implementation, the method further includes: receiving, by the access network device, signal quality of a neighboring cell of the cell that is sent by the terminal device or an identifier that is of a to-be-reported beam of the neighboring cell and that is sent by the terminal device.

A third aspect of this application provides a terminal device, including:

a receiving module, configured to receive a plurality of beams, where the plurality of beams carry synchronization signal blocks, and the plurality of beams belong to one cell; and

a processing module, configured to obtain signal quality of the plurality of beams based on the synchronization signal blocks, where the signal quality of the plurality of beams includes signal quality of a same beam at different moments, where

the processing module is further configured to obtain signal quality of the cell based on the signal quality of the plurality of beams.

In a possible implementation, at least one piece of signal quality of one beam in the signal quality of the plurality of beams is obtained by using a synchronization signal block of the beam.

In a possible implementation, that the processing module is further configured to obtain signal quality of the cell based on the signal quality of the plurality of beams includes:

separately performing filtering processing on the signal quality of the plurality of beams; and

obtaining the signal quality of the cell based on filtered signal quality of the plurality of beams.

In a possible implementation, the receiving module is further configured to: receive only some beams of the cell when the signal quality of the cell exceeds a second quality threshold.

In a possible implementation, the processing module is further configured to:

obtain a synchronization signal burst set sending period of the cell;

that a receiving module is configured to receive the plurality of beams includes:

receiving, within at least two synchronization signal burst set sending periods, the plurality of beams sent by an access network device; and

that a processing module is configured to obtain signal quality of the plurality of beams based on the synchronization signal blocks includes:

determining that beam signal quality detected on synchronization signal blocks at a same corresponding position in the at least two synchronization signal burst set sending periods belongs to a same beam.

In a possible implementation, the processing module is further configured to:

obtain a synchronization signal burst set sending period of the cell;

that a receiving module is configured to receive the plurality of beams includes:

receiving, within the synchronization signal burst set sending period, the plurality of beams sent by an access network device; and

that a processing module is configured to obtain signal quality of the plurality of beams based on the synchronization signal blocks includes:

determining, based on a beam timing index included in each received synchronization signal block, an identifier of a beam on which each synchronization signal block is sent; and

determining that signal quality of beams having a same identifier belongs to a same beam.

In a possible implementation, that the processing module determines, based on a beam timing index included in each received synchronization signal block, an identifier of a beam on which each synchronization signal block is sent includes:

performing a modulo operation on the beam timing index included in each synchronization signal block and the synchronization signal burst set sending period, to obtain the identifier of the beam on which each synchronization signal block is sent; or

determining that the beam timing index included in each synchronization signal block is the identifier of the beam on which each synchronization signal block is sent.

In a possible implementation, the terminal device further includes: a sending module, where

the receiving module is further configured to receive a plurality of beams of a neighboring cell of the cell;

the processing module is further configured to:

obtain signal quality of the neighboring cell based on the plurality of beams of the neighboring cell; and

determine an identifier of a to-be-reported beam from the plurality of beams of the neighboring cell, and/or determine an identifier of a to-be-reported beam from the plurality of beams of the cell; and

the sending module is configured to send the signal quality of the neighboring cell, the signal quality of the cell, and the identifier of the to-be-reported beam of the cell and/or the identifier of the to-be-reported beam of the neighboring cell to an access network device.

In a possible implementation, that the processing module determines an identifier of a to-be-reported beam from the plurality of beams of the neighboring cell, and/or determines an identifier of a to-be-reported beam from the plurality of beams of the cell includes:

determining a beam whose filtered signal quality is greater than or equal to a preset third quality threshold as a to-be-reported beam based on the filtered signal quality of the beams of the cell, and/or determining a beam whose filtered signal quality is greater than or equal to the third quality threshold as a to-be-reported beam based on filtered signal quality of the beams of the neighboring cell; or

determining N1beams whose signal quality is the best from the plurality of beams of the cell as to-be-reported beams based on a beam reporting quantity N1configured by the access network device, and/or determining N1beams whose signal quality is the best from the plurality of beams of the neighboring cell as to-be-reported beams.

In a possible implementation, the processing module is further configured to:

select B beams whose filtered signal quality is the best from the plurality of beams, where B is greater than or equal to 1 and is less than or equal to N, and N is a beam quantity threshold and is greater than or equal to 1;

add up the filtered signal quality of the B beams, to obtain a signal quality sum; and

determine the signal quality of the cell based on the signal quality sum.

In a possible implementation, that the processing module selects B beams whose filtered signal quality is the best from the plurality of beams includes:

selecting M beams whose signal quality is greater than a third quality threshold from the plurality of beams based on the filtered signal quality of the plurality of beams; and

when M is greater than N and B is equal to N, selecting N beams from the M beams; or

when M is less than N and B is equal to M, determining that the M beams are beams whose filtered signal quality is the best.

In a possible implementation, that the processing module determines the signal quality of the cell based on the signal quality sum includes:

determining the signal quality sum as the signal quality of the cell; or

determining a ratio of the signal quality sum to N as the signal quality of the cell; or

determining a ratio of the signal quality sum to B as the signal quality of the cell.

In a possible implementation, that the receiving module receives only some beams of the cell includes:

receiving only synchronization signal blocks that are sent on B beams whose filtered signal quality is the best in the cell, where B is greater than or equal to 1 and is less than or equal to N, and N is a beam quantity threshold and is greater than or equal to 1; or

receiving only a synchronization signal burst in which the synchronization signal blocks sent on the B beams are located.

In a possible implementation, that the receiving module receives only some beams of the cell includes:

receiving only a synchronization signal block that is sent on a beam whose filtered signal quality is the best in the cell; or

receiving only a synchronization signal burst in which a synchronization signal block sent on a beam whose filtered signal quality is the best is located.

A fourth aspect of this application provides an access network device, including:

a sending module, configured to send synchronization signal blocks on a plurality of beams of a cell, where

the sending module is further configured to send a message to a terminal device, where the message indicates a quantity of to-be-reported beams or at least one quality threshold of a to-be-reported beam of the terminal device, and the at least one quality threshold is used for beam measurement; and

a receiving module, configured to receive signal quality of the cell from the terminal device or an identifier that is of a to-be-reported beam of the cell and that is sent by the terminal device, where the signal quality of the cell is obtained by using the synchronization signal blocks.

In a possible implementation, the receiving module is further configured to:

receive signal quality of a neighboring cell of the cell that is sent by the terminal device or an identifier that is of a to-be-reported beam of the neighboring cell and that is sent by the terminal device.

A fifth aspect of this application provides a terminal device, including a processor and a memory, where the memory is configured to store an instruction, and the processor is configured to execute the instruction stored in the memory, so that the terminal device performs the following method:

measuring signal quality of a plurality of beams, where the signal quality of the plurality of beams is obtained by using synchronization signal blocks, the signal quality of the plurality of beams includes signal quality of a same beam at different moments, and the plurality of beams belong to one cell; and

obtaining signal quality of the cell based on the signal quality of the plurality of beams.

In a possible implementation, at least one piece of signal quality of one beam in the signal quality of the plurality of beams is obtained by using a synchronization signal block of the beam.

In a possible implementation, that the processor obtains signal quality of the cell based on the signal quality of the plurality of beams includes:

separately performing filtering processing on the signal quality of the plurality of beams; and

obtaining the signal quality of the cell based on filtered signal quality of the plurality of beams.

In a possible implementation, the processor is further configured to:

measure only some beams of the cell when the signal quality of the cell exceeds a second quality threshold.

In a possible implementation, the processor is further configured to:

obtain a synchronization signal burst set sending period of the cell; and

that the processor measures signal quality of a plurality of beams includes:

detecting, within at least two synchronization signal burst set sending periods, synchronization signal blocks that are sent by an access network device on the plurality of beams, to obtain the signal quality of the plurality of beams; and

determining that beam signal quality detected on synchronization signal blocks at a same corresponding position in the at least two synchronization signal burst set sending periods belongs to a same beam.

In a possible implementation, the processor is further configured to:

obtain a synchronization signal burst set sending period of the cell; and

that the processor measures signal quality of a plurality of beams includes:

detecting, within the synchronization signal burst set sending period, synchronization signal blocks that are sent by an access network device on the plurality of beams, to obtain the signal quality of the plurality of beams;

determining, based on a beam timing index included in each received synchronization signal block, an identifier of a beam on which each synchronization signal block is sent; and

determining that signal quality of beams having a same identifier belongs to a same beam.

In a possible implementation, that the processor determines, based on a beam timing index included in each received synchronization signal block, an identifier of a beam on which each synchronization signal block is sent includes:

performing a modulo operation on the beam timing index included in each synchronization signal block and the synchronization signal burst set sending period, to obtain the identifier of the beam on which each synchronization signal block is sent; or

determining that the beam timing index included in each synchronization signal block is the identifier of the beam on which each synchronization signal block is sent.

In a possible implementation, the processor is further configured to:

measure a neighboring cell of the cell, to obtain signal quality of the neighboring cell;

determine an identifier of a to-be-reported beam from the plurality of beams of the neighboring cell, and/or determine an identifier of a to-be-reported beam from the plurality of beams of the cell; and

send the signal quality of the neighboring cell, the signal quality of the cell, and the identifier of the to-be-reported beam of the cell and/or the identifier of the to-be-reported beam of the neighboring cell to an access network device.

In a possible implementation, that the processor determines an identifier of a to-be-reported beam from the beams of the neighboring cell, and/or determines an identifier of a to-be-reported beam from the beams of the cell includes:

determining a beam whose filtered signal quality is greater than or equal to a preset third quality threshold as a to-be-reported beam based on the filtered signal quality of the beams of the cell, and/or determining a beam whose filtered signal quality is greater than or equal to the third quality threshold as a to-be-reported beam based on filtered signal quality of the beams of the neighboring cell; or

determining N1beams whose signal quality is the best from the plurality of beams of the cell as to-be-reported beams based on a beam reporting quantity N1configured by the access network device, and/or determining N1beams whose signal quality is the best from the plurality of beams of the neighboring cell as to-be-reported beams.

In a possible implementation, that the processor obtains the signal quality of the cell based on filtered signal quality of the plurality of beams includes:

selecting B beams whose filtered signal quality is the best from the plurality of beams, where B is greater than or equal to 1 and is less than or equal to N, and N is a beam quantity threshold and is greater than or equal to 1;

adding up the filtered signal quality of the B beams, to obtain a signal quality sum; and

determining the signal quality of the cell based on the signal quality sum.

In a possible implementation, that the processor selects B beams whose filtered signal quality is the best from the plurality of beams includes:

selecting M beams whose signal quality is greater than a third quality threshold from the plurality of beams based on the filtered signal quality of the plurality of beams; and

when M is greater than N and B is equal to N, selecting N beams from the M beams; or

when M is less than N and B is equal to M, determining that the M beams are beams whose filtered signal quality is the best.

In a possible implementation, that the processor determines the signal quality of the cell based on the signal quality sum includes:

determining the signal quality sum as the signal quality of the cell; or

determining a ratio of the signal quality sum to N as the signal quality of the cell; or

determining a ratio of the signal quality sum to B as the signal quality of the cell.

In a possible implementation, that the processor measures only some beams of the cell includes:

measuring only synchronization signal blocks that are sent on B beams whose filtered signal quality is the best in the cell, where B is greater than or equal to 1 and is less than or equal to N, and N is a beam quantity threshold and is greater than or equal to 1; or

measuring only a synchronization signal burst in which the synchronization signal blocks sent on the B beams are located.

In a possible implementation, that the processor measures only some beams of the cell includes:

measuring only a synchronization signal block that is sent on a beam whose filtered signal quality is the best in the cell; or

measuring only a synchronization signal burst in which a synchronization signal block that is sent on a beam whose filtered signal quality is the best is located.

A sixth aspect of this application provides an access network device, including a processor and a memory, where the memory is configured to store an instruction, and the processor is configured to execute the instruction stored in the memory, so that the access network device performs the following method:

sending synchronization signal blocks on a plurality of beams of a cell;

sending, by the access network device, a message to a terminal device, where the message indicates a quantity of to-be-reported beams or at least one quality threshold of a to-be-reported beam of the terminal device, and the at least one quality threshold is used for beam measurement; and

receiving, by the access network device, signal quality of the cell from the terminal device or an identifier that is of a to-be-reported beam of the cell and that is sent by the terminal device, where the signal quality of the cell is obtained by using the synchronization signal blocks.

In a possible implementation, the processor is further configured to:

receive signal quality of a neighboring cell of the cell that is sent by the terminal device or an identifier that is of a to-be-reported beam of the neighboring cell and that is sent by the terminal device.

According to the measurement method, the terminal device, and the access network device provided in this application, the terminal device measures signal quality of a plurality of beams, where the signal quality of the plurality of beams is obtained by using synchronization signal blocks, the signal quality of the plurality of beams includes signal quality of a same beam at different moments, and the plurality of beams belong to one cell; and obtains signal quality of the cell based on the signal quality of the plurality of beams. In this way, cell measurement based on a synchronization signal is implemented, and the signal quality of the cell obtained based on the signal quality of the plurality of beams at the different moments is more accurate.

