Beam-based communication method and related device

Abstract

Embodiments of the present application provide a beam-based communication method and a related device, the method comprising: a terminal device receiving first indication information for a transmission configuration indication, the first indication information being used for activating a TCI state of a candidate cell, the activated TCI state of the candidate cell comprising a first TCI state, the first TCI state comprising one or more TCI states; the terminal device measures a first synchronization signal block (SSB) according to the first indication information to obtain a first measurement result, the first SSB and at least one channel state information reference signal (CSI-RS) have a quasi co-location QCL relationship, the at least one CSI-RS is a reference signal in QCL information of a first TCI state, the type of the QCL information of the first TCI state is type A and / or type D, the first SSB is an SSB of a candidate cell, and the second SSB is an SSB of the candidate cell. The at least one CSI-RS is the CSI-RS of the candidate cell. Through the first indication information, the SSB associated with the TCI state is measured in advance, and the TCI state is rapidly activated. The communication interruption time of the terminal device is reduced, and the communication quality of the terminal device is improved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a beam-based communication method and related devices. Background Art

[0002] The fifth generation mobile communication system (5th generation, 5G) uses high-frequency communication, that is, it uses ultra-high frequency band (>6GHz) signals to transmit data. A major problem with high-frequency communication is that the signal energy drops sharply with the transmission distance, resulting in a short signal transmission distance. In order to overcome this problem, high-frequency communication uses analog beam technology, which is processed by a large-scale antenna array to concentrate the signal energy in a smaller range to form a signal similar to a light beam, called an analog beam (referred to as beam), thereby extending the transmission distance. Network equipment can generate different beams pointing to different transmission directions. In downlink data transmission, the network device will use a specific beam to send data to the terminal device and inform the terminal device of the transmission beam information it uses, so that the terminal device will use the correct receiving beam (that is, the receiving beam corresponding to the transmitting beam) to receive the data sent by the network device.

[0003] During the process of switching the terminal device from the serving cell to the candidate cell, the terminal device receives a switching command sent by the serving cell, and the switching command is also used to indicate the transmission configuration indicator (TCI) state. In response to the switching command, the terminal device applies the configuration information related to the candidate cell, and the configuration information of the candidate cell includes the TCI state indicated by the switching command. The terminal device obtains the resource configuration information of the corresponding reference signal according to the TCI state, and the reference signal includes a tracking reference signal (TRS). After parsing the above configuration information, the tracking and measurement phase of the terminal device is entered, which is as follows: First, the terminal device tracks and measures the above-determined SSB, and determines the beam information according to the measurement result of the SSB. Then, the terminal device needs to track and measure the above-determined TRS according to the beam information, and the TRS has a corresponding relationship with the SSB to obtain the measurement result of the TRS. Finally, the terminal device activates the TCI state according to the measurement result of the TRS.

[0004] The applicant's research found that the terminal device can only parse the configuration information related to the candidate cell after receiving the switching command, and then measure the SSB and TRS corresponding to the TCI state of the candidate cell, and finally activate the TCI state according to the measurement results. The above process has a large time delay, which causes the terminal device to suspend communication for a long time and reduces the communication quality. Summary of the invention

[0005] In a first aspect, an embodiment of the present application proposes a beam-based communication method, including:

[0006] The terminal device receives a transmission configuration indicating first indication information, where the first indication information is used to activate a TCI state of a candidate cell, where the TCI state of the activated candidate cell includes a first TCI state, where the first TCI state includes one or more TCI states;

[0007] The terminal device measures a first synchronization signal block SSB according to the first indication information to obtain a first measurement result, wherein the first SSB has a quasi-co-site QCL relationship with at least one channel state information reference signal CSI-RS, the at least one CSI-RS is a reference signal in the QCL information of the first TCI state, the type of the QCL information of the first TCI state is type A and / or type D, the first SSB is the SSB of the candidate cell, and the at least one CSI-RS is the CSI-RS of the candidate cell.

[0008] Optionally, the first TCI state also includes a TCI state in which the type of QCL information is type B and / or type C. The embodiment of the present application does not limit the type of QCL information in the first TCI state.

[0009] In an embodiment of the present application, when a terminal device switches from a serving cell to a candidate cell, the first TCI state to be activated can be determined according to the received first indication information. Then, the first synchronization signal block SSB is determined according to the first TCI state, and the first SSB is pre-measured to obtain a first measurement result. Through the first indication information, the SSB associated with the TCI state is pre-measured to achieve rapid activation of the TCI state. The communication interruption time of the terminal device is reduced and the communication quality of the terminal device is improved.

[0010] In combination with the first aspect, in an optional implementation of the first aspect, the method also includes: the terminal device receives a switching command, the switching command instructs the terminal device to switch from the serving cell to the candidate cell, the switching command is used to indicate a second TCI state, and the second TCI state belongs to the first TCI state; the terminal device measures the reference signal corresponding to the second TCI state according to the first measurement result to obtain a second measurement result; the terminal device activates the second TCI state according to the second measurement result.

[0011] In an embodiment of the present application, after the terminal device receives the switching command, the reference signal corresponding to the second TCI state is measured according to the first measurement result to obtain a second measurement result. According to the second measurement result, the second TCI state is activated, and the activated second TCI state is used to transmit data. The communication interruption time of the terminal device is reduced and the communication quality of the terminal device is improved.

[0012] In combination with the first aspect, in an optional implementation of the first aspect, the terminal device measures the first synchronization signal block SSB according to the first indication information to obtain the first measurement result, including: the terminal device determines the QCL information of the first TCI state according to the first indication information; the terminal device determines the at least one CSI-RS corresponding to the first TCI state according to the QCL information of the first TCI state; the terminal device determines the third TCI state according to the configuration information of the at least one CSI-RS, wherein the configuration information of the at least one CSI-RS includes identification information of the third TCI state, and the third TCI state is used to determine the receiving parameters of the reference signal corresponding to the first TCI state; the terminal device determines the first SSB according to the QCL information of the third TCI state, wherein the QCL information of the third TCI state includes index information of the first SSB; the terminal device measures the first SSB to obtain the first measurement result.

[0013] Specifically, the configuration information of the at least one CSI-RS includes identification information of the third TCI state, and the third TCI state is used to determine the receiving parameters of the reference signal corresponding to the first TCI state. The receiving parameters include but are not limited to: time offset compensation, frequency offset compensation, and / or receiving beam, etc. Since the QCL information of the third TCI state includes the index information of the first SSB, the terminal device determines the first SSB based on the index information of the first SSB in the QCL information of the third TCI state. Through the above method, the first SSB is measured to obtain the first measurement result, which improves the implementation flexibility of the solution.

[0014] In combination with the first aspect, in an optional implementation of the first aspect, the quasi-co-located QCL type of the third TCI state is type C and / or type D. The TCI state in which the QCL type is type C and / or type D is associated with the SSB, so the first SSB can be determined according to the third TCI state.

[0015] In combination with the first aspect, in an optional implementation of the first aspect, the first TCI state also includes a fourth TCI state, and the quasi-co-located QCL type of the fourth TCI state is type C and / or type D. The first TCI state may include TCI states of multiple QCL types, thereby improving the implementation flexibility of the solution.

[0016] In combination with the first aspect, in an optional implementation of the first aspect, the terminal device measures the first synchronization signal block SSB according to the first indication information to obtain the first measurement result, including: the terminal device determines the QCL information of the fourth TCI state according to the first indication information, and the QCL information of the fourth TCI state indicates that the source reference signal of the fourth TCI state includes SSB; the terminal device determines the first SSB according to the QCL information of the fourth TCI state, and the QCL information of the fourth TCI state includes the index information of the first SSB; the terminal device measures the first SSB to obtain the first measurement result. Through the above method, the first SSB is measured to obtain the first measurement result, which improves the implementation flexibility of the solution.

[0017] In combination with the first aspect, in an optional implementation of the first aspect, before the terminal device receives the first indication information, the method also includes: the terminal device receives configuration information, and the configuration information includes QCL information of the TCI state of the candidate cell and / or relevant information of the CSI-RS of the candidate cell. The configuration information is configuration information related to the TCI state of the candidate cell, for example, the configuration information includes: quasi-co-site QCL information of the TCI state of the candidate cell and / or relevant information of the CSI-RS of the candidate cell. The relevant information of the CSI-RS of the candidate cell specifically includes the configuration information of the CSI-RS, and the configuration information is used to determine the time domain and frequency domain resource configuration of the CSI-RS. The configuration information may also include the configuration information of the TRS of the candidate cell, including the TCI state identifier required for receiving the TRS. By parsing the configuration information in advance, the processing delay of the terminal device is reduced, the communication interruption time of the terminal device is reduced, and the communication quality is improved.

[0018] In combination with the first aspect, in an optional implementation of the first aspect, the terminal device measures the reference signal corresponding to the second TCI state according to the first measurement result, and before obtaining the second measurement result, the method further includes: the terminal device determines the TCI corresponding to the first SSB as the default beam according to the first measurement result, and the default beam is used to transmit signals with the switched service cell, and the switched service cell belongs to the candidate cell. By using the TCI corresponding to the first SSB as the default beam and using the default beam to transmit signals before the terminal device activates the second TCI state, the communication interruption time of the terminal device is further reduced and the communication quality is improved.

[0019] In combination with the first aspect, in an optional implementation of the first aspect, the TCI corresponding to the reference signal in the first TCI state is not allowed to be indicated by the switching command, or the TCI corresponding to the reference signal in the first TCI state is not allowed to be used for data transmission after receiving the switching command. The TCI corresponding to the reference signal in the first TCI state is not allowed to be indicated by the switching command, which can also be understood as: the TCI indicated by the switching command does not include the TCI corresponding to the reference signal in the first TCI state, and the TCI activated by the switching command is used for data transmission. The reference signal includes but is not limited to: TRS or CSI-RS. By restricting the TCI from performing data transmission, the normal communication of the terminal device is avoided from being affected, and the communication quality of the terminal device is improved.

[0020] In a second aspect, an embodiment of the present application proposes a beam-based communication method, including:

[0021] The terminal device receives a transmission configuration indicating first indication information, where the first indication information is used to activate a TCI state of a candidate cell, where the TCI state of the activated candidate cell includes a first TCI state, where the first TCI state includes one or more TCI states;

[0022] The terminal device measures the first synchronization signal block SSB according to the first indication information to obtain a first measurement result, wherein the first SSB has a quasi-co-site QCL relationship with at least one channel state information reference signal CSI-RS, the at least one CSI-RS is a reference signal in the QCL information of the first TCI state, the type of the QCL information of the first TCI state is type C and / or type D, the first SSB is the SSB of the candidate cell, and the at least one CSI-RS is the CSI-RS of the candidate cell.

[0023] Optionally, the first TCI state also includes a TCI state in which the type of QCL information is type B and / or type C. The embodiment of the present application does not limit the type of QCL information in the first TCI state.

[0024] In an embodiment of the present application, when a terminal device switches from a serving cell to a candidate cell, the first TCI state to be activated can be determined according to the received first indication information. Then, the first synchronization signal block SSB is determined according to the first TCI state, and the first SSB is pre-measured to obtain a first measurement result. Through the first indication information, the SSB associated with the TCI state is pre-measured to achieve rapid activation of the TCI state. The communication interruption time of the terminal device is reduced and the communication quality of the terminal device is improved.

[0025] In combination with the second aspect, in an optional implementation of the second aspect, the method also includes: the terminal device receives a switching command, the switching command instructs the terminal device to switch from the serving cell to the candidate cell, the switching command is used to indicate a second TCI state, and the second TCI state belongs to the first TCI state; the terminal device measures the reference signal corresponding to the second TCI state according to the first measurement result to obtain a second measurement result; the terminal device activates the second TCI state according to the second measurement result.

[0026] In an embodiment of the present application, after the terminal device receives the switching command, the reference signal corresponding to the second TCI state is measured according to the first measurement result to obtain a second measurement result. According to the second measurement result, the second TCI state is activated, and the activated second TCI state is used to transmit data. The communication interruption time of the terminal device is reduced and the communication quality of the terminal device is improved.

[0027] In combination with the second aspect, in an optional implementation manner of the second aspect, the first TCI state includes a fourth TCI state, and the quasi-co-site QCL type of the fourth TCI state is type C and / or type D.

[0028] In combination with the second aspect, in an optional implementation of the second aspect, the terminal device measures the first synchronization signal block SSB according to the first indication information to obtain the first measurement result, including: the terminal device determines the QCL information of the fourth TCI state according to the first indication information, and the QCL information of the fourth TCI state indicates that the source reference signal of the fourth TCI state includes SSB; the terminal device determines the first SSB according to the QCL information of the fourth TCI state, and the QCL information of the fourth TCI state includes the index information of the first SSB; the terminal device measures the first SSB to obtain the first measurement result. Through the above method, the first SSB is measured to obtain the first measurement result, which improves the implementation flexibility of the solution.

[0029] In combination with the second aspect, in an optional implementation of the second aspect, before the terminal device receives the first indication information, the method also includes: the terminal device receives configuration information, and the configuration information includes QCL information of the TCI state of the candidate cell and / or relevant information of the CSI-RS of the candidate cell. The configuration information is configuration information related to the TCI state of the candidate cell, for example, the configuration information includes: quasi-co-site QCL information of the TCI state of the candidate cell and / or relevant information of the CSI-RS of the candidate cell. The relevant information of the CSI-RS of the candidate cell specifically includes the configuration information of the CSI-RS, and the configuration information is used to determine the time domain and frequency domain resource configuration of the CSI-RS. The configuration information may also include the configuration information of the TRS of the candidate cell, including the TCI state identifier required for receiving the TRS. By parsing the configuration information in advance, the processing delay of the terminal device is reduced, the communication interruption time of the terminal device is reduced, and the communication quality is improved.

[0030] In combination with the second aspect, in an optional implementation of the second aspect, the terminal device measures the reference signal corresponding to the second TCI state according to the first measurement result, and before obtaining the second measurement result, the method further includes: the terminal device determines the TCI corresponding to the first SSB as the default beam according to the first measurement result, and the default beam is used to transmit signals with the switched service cell, and the switched service cell belongs to the candidate cell. By using the TCI corresponding to the first SSB as the default beam and using the default beam to transmit signals before the terminal device activates the second TCI state, the communication interruption time of the terminal device is further reduced and the communication quality is improved.

[0031] In combination with the second aspect, in an optional implementation of the second aspect, the TCI corresponding to the reference signal in the first TCI state is not allowed to be indicated by the switching command, or the TCI corresponding to the reference signal in the first TCI state is not allowed to be used for data transmission after receiving the switching command. The TCI corresponding to the reference signal in the first TCI state is not allowed to be indicated by the switching command, which can also be understood as: the TCI indicated by the switching command does not include the TCI corresponding to the reference signal in the first TCI state, and the TCI activated by the switching command is used for data transmission. The reference signal includes but is not limited to: TRS or CSI-RS. By restricting the TCI from performing data transmission, the normal communication of the terminal device is avoided from being affected, and the communication quality of the terminal device is improved.

[0032] In a third aspect, an embodiment of the present application proposes a beam-based communication method, including:

[0033] The terminal device receives a handover command, wherein the handover command instructs the terminal device to handover from a serving cell to a candidate cell;

[0034] When any one or more of the first conditions are met, the terminal device determines a default beam, where the default beam is used to transmit signals with a switched serving cell, where the switched serving cell belongs to the candidate cell;

[0035] The first condition includes: the transmission configuration indication TCI is not indicated in the handover command, and the terminal device determines the TA according to the measurement result of the downlink reference signal;

[0036] Alternatively, the timing advance TA is not indicated in the switching command, and the terminal device determines the TA according to the measurement result of the downlink reference signal;

[0037] Alternatively, the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is the same as the TA of the serving cell,

[0038] Alternatively, the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is 0;

[0039] Alternatively, the TCI indicated in the handover command is not activated in advance;

[0040] Alternatively, the source reference signal of the TCI indicated in the switching command includes a channel state information reference signal CSI-RS, and the terminal device does not measure the CSI-RS before receiving the switching command;

[0041] Alternatively, the switching command indicates TCI, and the terminal device feeds back a hybrid automatic repeat request response HARQ-ACK according to the switching command, and the time of feeding back the HARQ-ACK does not reach the beam effective time point.

[0042] Specifically, the terminal device determines the TA based on the measurement result of the downlink reference signal, including: before the terminal device switches from the serving cell to the candidate cell, the network device of the serving cell configures the terminal device. The specific configuration information includes but is not limited to: the terminal device calculates the timing advance based on the time difference between the measured SSB arrival time of the serving cell and the measured SSB arrival time of the candidate cell. According to the configured information, the terminal device calculates the timing advance based on the time difference between the two SSB arrival times.

[0043] In the embodiment of the present application, when the terminal device does not have a valid beam indicated by the switching command and cannot determine the default beam through the random access channel (RACH) beam, the terminal device can determine the default beam through the above method, and the default beam is used to transmit signals with the serving cell after switching. The communication interruption time of the terminal device is reduced and the communication quality of the terminal device is improved.

[0044] In combination with the third aspect, in an optional implementation of the third aspect, when one or more of the following one or more of the first condition is met, the terminal device determines the default beam, including: the first condition includes: the transmission configuration indication TCI is not indicated in the switching command, and the terminal device determines the TA according to the measurement result of the downlink reference signal; or, the timing advance TA is not indicated in the switching command, and the terminal device determines the TA according to the measurement result of the downlink reference signal; the terminal device determines the default beam, including: the terminal device determines the second synchronization signal block SSB as the default beam, the second SSB is the SSB of the candidate cell, the second SSB is used to measure the TA of the candidate cell, or the second SSB has a quasi-co-location QCL relationship with the reference signal for measuring the TA of the candidate cell. Through the above method, under the specific first condition, the terminal device can determine the second SSB as the default beam, which improves the implementation flexibility of the solution.

[0045] In combination with the third aspect, in an optional implementation of the third aspect, the second SSB is the first SSB in a first SSB set, the first SSB set includes multiple SSBs, and the first SSB set is used to measure the TA of the candidate cell; or, the second SSB is the SSB of the candidate cell that the terminal device last reported to the network device. Through the above method, the communication quality of the terminal device is improved.

[0046] In combination with the third aspect, in an optional implementation of the third aspect, the second SSB is the SSB of the candidate cell that the terminal device reported to the network device most recently, including: the second SSB is the SSB with the largest reference signal power RSRP among the SSBs of the candidate cell reported by the terminal device to the network device. Specifically, the terminal device will periodically measure the SSB of the candidate cell, and then report the measurement strength to the network device of the serving cell. The serving cell decides whether to switch from the serving cell to the candidate cell based on the measurement strength. Through the above method, the communication quality of the terminal device is improved and the switching interruption time is reduced.

[0047] In combination with the third aspect, in an optional implementation of the third aspect, when one or more of the following of the first condition is met, the terminal device determines the default beam, including: the first condition, including: TA is indicated in the switching command, and the terminal device determines that the TA of the candidate cell is the same as the TA of the serving cell; or TA is indicated in the switching command, and the terminal device determines that the TA of the candidate cell is 0; the terminal device determines the default beam, including: the terminal device determines the fifth TCI state indicated by the switching command according to the switching command; the terminal device determines the first reference signal as the default beam, or the terminal device determines the synchronization signal block SSB associated with the first reference signal as the default beam, and the first reference signal is the reference signal indicated by the quasi-co-site QCL information of the fifth TCI state. Through the above method, under the specific first condition, the terminal device can determine the synchronization signal block SSB associated with the first reference signal or the first reference signal as the default beam, which improves the implementation flexibility of the solution and reduces the switching interruption time.

[0048] In combination with the third aspect, in an optional implementation of the third aspect, the type of the QCL information of the third TCI state is type D; and the first reference signal is a channel state information reference signal CSI-RS.

[0049] In combination with the third aspect, in an optional implementation of the third aspect, when one or more of the following of the first condition is met, the terminal device determines the default beam, including: the first condition includes: TA is indicated in the switching command, and the terminal device determines that the TA of the candidate cell is the same as the TA of the serving cell; or, TA is indicated in the switching command, and the terminal device determines that the TA of the candidate cell is 0; the terminal device determines the default beam, including: the terminal device determines the SSB with the largest reference signal reception power from the synchronization signal block SSB of the candidate cell reported by the terminal device to the network device; the terminal device determines the SSB with the largest reference signal reception power as the default beam. Through the above method, under the specific first condition, the terminal device can determine the SSB with the largest reference signal reception power as the default beam, which improves the implementation flexibility of the solution, ensures the communication quality of the terminal device, and reduces the switching interruption time.

[0050] In combination with the third aspect, in an optional implementation of the third aspect, the first condition also includes: the service cell includes a primary cell and at least one secondary cell, or the candidate cell includes a primary cell and at least one secondary cell, and the primary cell and the secondary cell are in the same timing advance group TAG; the terminal device determines the default beam, including: the terminal device determines to measure the synchronization signal block SSB of the TA of the primary cell as the default beam. Specifically, the terminal device only obtains the TA of the primary cell (primary cell, PCell), and the secondary cell (secondary cell, SCell) and the PCell are in the same timing advance group (Timing Advance Group, TAG). For the scenario in which the terminal device configures carrier aggregation in the service cell, and the service cell (candidate cell) after switching is also configured with carrier aggregation, the default beam can be determined. The implementation flexibility of the solution is improved, the communication quality of the terminal device is ensured, and the switching interruption time is reduced.

[0051] In combination with the third aspect, in an optional implementation of the third aspect, the default beam is used to transmit signals in the primary cell, and the default beam is also used to transmit signals in the secondary cell; the primary cell and the secondary cell are configured in a first set, and the first set is used to configure multiple cells to update beams according to at least one beam indication.

[0052] In combination with the third aspect, in an optional implementation of the third aspect, the method also includes: the terminal device obtains the TA of the target cell among the multiple cells indicated by the first set, and the target cell is any one of the cells indicated by the first set; the terminal device determines a third synchronization signal block SSB according to the TA of the target cell, and the third SSB is used to measure the TA of the target cell, and the third SSB is the SSB of the candidate cell; the terminal device determines the third SSB as the default beam for any one or more cells in the first set.

[0053] In a fourth aspect, an embodiment of the present application provides a communication device, including:

[0054] A transceiver module, configured to receive first indication information indicating a transmission configuration, where the first indication information is used to activate a TCI state of a candidate cell, where the TCI state of the activated candidate cell includes a first TCI state, where the first TCI state includes one or more TCI states;

[0055] A processing module is used to measure a first synchronization signal block SSB according to the first indication information to obtain a first measurement result, wherein the first SSB has a quasi-co-site QCL relationship with at least one channel state information reference signal CSI-RS, the at least one CSI-RS is a reference signal in the QCL information of the first TCI state, the type of the QCL information of the first TCI state is type A and / or type D, the first SSB is the SSB of the candidate cell, and the at least one CSI-RS is the CSI-RS of the candidate cell.

[0056] In some optional implementations of the present application, the transceiver module is further used to receive a handover command, the handover command instructing the terminal device to switch from the serving cell to the candidate cell, the handover command is used to indicate a second TCI state, and the second TCI state belongs to the first TCI state;

[0057] The processing module is further configured to measure, according to the first measurement result, a reference signal corresponding to the second TCI state to obtain a second measurement result;

[0058] The processing module is further used to activate the second TCI state according to the second measurement result.

[0059] In some optional implementations of the present application, the processing module is further used to determine the QCL information of the first TCI state according to the first indication information;

[0060] The processing module is further configured to determine, according to the QCL information of the first TCI state, the at least one CSI-RS corresponding to the first TCI state;

[0061] The processing module is further used to determine a third TCI state according to the configuration information of the at least one CSI-RS, wherein the configuration information of the at least one CSI-RS includes identification information of the third TCI state, and the third TCI state is used to determine a receiving parameter for receiving a reference signal corresponding to the first TCI state;

[0062] The processing module is further configured to determine the first SSB according to the QCL information of the third TCI state, wherein the QCL information of the third TCI state includes index information of the first SSB;

[0063] The processing module is also used to measure the first SSB to obtain the first measurement result.

[0064] In some optional embodiments of the present application, the quasi-co-site QCL type of the third TCI state is type C and / or type D.

[0065] In some optional embodiments of the present application, the first TCI state also includes a fourth TCI state, and the quasi-co-site QCL type of the fourth TCI state is type C and / or type D.

[0066] In some optional implementations of the present application, the processing module is further used to determine the QCL information of the fourth TCI state according to the first indication information, and the QCL information of the fourth TCI state indicates that the source reference signal of the fourth TCI state includes SSB;

[0067] The processing module is further used to determine the first SSB according to the QCL information of the fourth TCI state, where the QCL information of the fourth TCI state includes the index information of the first SSB;

[0068] The processing module is also used to measure the first SSB to obtain the first measurement result.

[0069] In some optional implementations of the present application, the transceiver module is further used to receive configuration information, where the configuration information includes QCL information of the TCI state of the candidate cell and / or related information of the CSI-RS of the candidate cell.

[0070] In some optional embodiments of the present application, the processing module is also used to determine the TCI corresponding to the first SSB as a default beam based on the first measurement result, and the default beam is used to transmit signals with the switched service cell, and the switched service cell belongs to the candidate cell.

[0071] In some optional embodiments of the present application, the TCI corresponding to the reference signal in the first TCI state is not allowed to be indicated by the switching command, or the TCI corresponding to the reference signal in the first TCI state is not allowed to be used for data transmission after receiving the switching command.

[0072] In a fifth aspect, an embodiment of the present application provides a communication device, characterized in that it includes:

[0073] A transceiver module, configured to receive first indication information indicating a transmission configuration, where the first indication information is used to activate a TCI state of a candidate cell, where the TCI state of the activated candidate cell includes a first TCI state, where the first TCI state includes one or more TCI states;

[0074] A processing module is used to measure a first synchronization signal block SSB according to the first indication information to obtain a first measurement result, wherein the first SSB has a quasi-co-site QCL relationship with at least one channel state information reference signal CSI-RS, the at least one CSI-RS is a reference signal in the QCL information of the first TCI state, the type of the QCL information of the first TCI state is type C and / or type D, the first SSB is the SSB of the candidate cell, and the at least one CSI-RS is the CSI-RS of the candidate cell.

[0075] In some optional implementations of the present application, the transceiver module is further used to receive a handover command, the handover command instructing the terminal device to switch from the serving cell to the candidate cell, the handover command is used to indicate a second TCI state, and the second TCI state belongs to the first TCI state;

[0076] The processing module is further configured to measure, according to the first measurement result, a reference signal corresponding to the second TCI state to obtain a second measurement result;

[0077] The processing module is further used to activate the second TCI state according to the second measurement result.

[0078] In some optional embodiments of the present application, the first TCI state also includes a fourth TCI state, and the quasi-co-site QCL type of the fourth TCI state is type C and / or type D.

[0079] In some optional implementations of the present application, the processing module is further used to determine the QCL information of the fourth TCI state according to the first indication information, and the QCL information of the fourth TCI state indicates that the source reference signal of the fourth TCI state includes SSB;

[0080] The processing module is further used to determine the first SSB according to the QCL information of the fourth TCI state, where the QCL information of the fourth TCI state includes the index information of the first SSB;

[0081] The processing module is also used to measure the first SSB to obtain the first measurement result.

[0082] In some optional implementations of the present application, the transceiver module is further used to receive configuration information, where the configuration information includes QCL information of the TCI state of the candidate cell and / or related information of the CSI-RS of the candidate cell.

[0083] In some optional embodiments of the present application, the processing module is also used to determine the TCI corresponding to the first SSB as a default beam based on the first measurement result, and the default beam is used to transmit signals with the switched service cell, and the switched service cell belongs to the candidate cell.

[0084] In some optional embodiments of the present application, the TCI corresponding to the reference signal in the first TCI state is not allowed to be indicated by the switching command, or the TCI corresponding to the reference signal in the first TCI state is not allowed to be used for data transmission after receiving the switching command.

[0085] In a sixth aspect, an embodiment of the present application provides a communication device, characterized in that it includes:

[0086] A transceiver module, used for a terminal device to receive a handover command, wherein the handover command instructs the terminal device to handover from a serving cell to a candidate cell;

[0087] a processing module, configured to determine a default beam when any one or more of the first conditions are met, wherein the default beam is used to transmit a signal with a serving cell after switching, and the serving cell after switching belongs to the candidate cell;

[0088] The first condition includes: the transmission configuration indication TCI is not indicated in the handover command, and the terminal device determines the TA according to the measurement result of the downlink reference signal;

[0089] Alternatively, the timing advance TA is not indicated in the switching command, and the terminal device determines the TA according to the measurement result of the downlink reference signal;

[0090] Alternatively, the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is the same as the TA of the serving cell,

[0091] Alternatively, the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is 0;

[0092] Alternatively, the TCI indicated in the handover command is not activated in advance;

[0093] Alternatively, the source reference signal of the TCI indicated in the switching command includes a channel state information reference signal CSI-RS, and the terminal device does not measure the CSI-RS before receiving the switching command;

[0094] Alternatively, the switching command indicates TCI, and the terminal device feeds back a hybrid automatic repeat request response HARQ-ACK according to the switching command, and the time of feeding back the HARQ-ACK does not reach the beam effective time point.

[0095] In some optional implementations of the present application, the processing module is further configured to determine the default beam when one or more of the following first conditions are met:

[0096] The first condition includes: the handover command does not indicate a transmission configuration indication TCI, and the terminal device determines the TA according to a measurement result of a downlink reference signal; or the handover command does not indicate a timing advance TA, and the terminal device determines the TA according to a measurement result of a downlink reference signal;

[0097] The processing module, used to determine the default beam, includes: the processing module, also used to determine a second synchronization signal block SSB as the default beam, the second SSB is the SSB of the candidate cell, the second SSB is used to measure the TA of the candidate cell, or the second SSB has a quasi-co-site QCL relationship with a reference signal for measuring the TA of the candidate cell.

[0098] In some optional implementations of the present application, the processing module is further configured to determine the default beam when one or more of the following first conditions are met:

[0099] The first condition includes: the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is the same as the TA of the serving cell; or the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is 0;

[0100] The processing module, used to determine the default beam, includes:

[0101] The processing module is further configured to determine, according to the switching command, a fifth TCI state indicated by the switching command;

[0102] The processing module is also used to determine a first reference signal as the default beam, or the terminal device determines the synchronization signal block SSB associated with the first reference signal as the default beam, and the first reference signal is the reference signal indicated by the quasi-co-site QCL information of the fifth TCI state.

[0103] In some optional implementations of the present application, the type of the QCL information of the third TCI state is type D;

[0104] The first reference signal is a channel state information reference signal CSI-RS.

[0105] In some optional implementations of the present application, the processing module is further configured to, when one or more of the following first conditions are met, determine, by the terminal device, the default beam, including:

[0106] The first condition includes: the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is the same as the TA of the serving cell; or the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is 0;

[0107] The processing module is further used to determine the default beam, including:

[0108] The processing module is further used to determine the SSB with the largest reference signal received power from the synchronization signal blocks SSB of the candidate cell reported by the terminal device to the network device;

[0109] The processing module is further used to determine the SSB with the largest reference signal receiving power as the default beam.

[0110] In some optional implementations of the present application, the first condition further includes: the serving cell includes a primary cell and at least one secondary cell, or the candidate cell includes a primary cell and at least one secondary cell, and the primary cell and the secondary cell are in the same timing advance group TAG;

[0111] The processing module is further used to determine the default beam, including:

[0112] The processing module is also used to determine the synchronization signal block SSB of the TA of the primary cell to be measured as the default beam.

[0113] In some optional implementations of the present application, the default beam is used for the primary cell to transmit signals, and the default beam is also used for the secondary cell to transmit signals;

[0114] The primary cell and the secondary cell are configured in a first set, and the first set is used to configure multiple cells to update beams according to at least one beam indication.

[0115] In the seventh aspect of the present application, a communication device is provided, which includes: a processor, a memory, an input / output device, and a bus; the memory stores computer instructions; when the processor executes the computer instructions in the memory, the memory stores computer instructions; when the processor executes the computer instructions in the memory, it is used to implement any one of the implementation methods of the first aspect, the second aspect, or the third aspect.

[0116] In a possible implementation manner of the seventh aspect, the processor, the memory, and the input and output devices are respectively connected to the bus.

[0117] An eighth aspect of the present application provides a computer program product comprising instructions, characterized in that when the computer program product is run on a computer, the computer is caused to execute any one of the implementation methods of the first aspect, the second aspect or the third aspect.

[0118] A ninth aspect of the present application provides a computer-readable storage medium, characterized in that it includes instructions, which, when executed on a computer, enable the computer to execute any implementation method of any of the first, second or third aspects.

[0119] The tenth aspect of the present application provides a chip system, which includes a processor, which is used to execute a computer program or instruction stored in a memory, so that the processor executes any implementation method of any of the above-mentioned first aspect, second aspect or third aspect.

[0120] In a possible design of the tenth aspect, the chip system also includes a memory, which is used to store computer programs or instructions necessary for the computer device. The processor is used to call and run the computer program or instruction from the memory. The chip system can be composed of a chip, or it can include a chip and other discrete devices.

[0121] In a possible design of the tenth aspect, the chip system also includes an input port and an output port, which are used to execute the receiving function and the sending function of the terminal device in any implementation of the first aspect, the second aspect or the third aspect, wherein the receiving function corresponds to the input port, and the sending function corresponds to the output port.

[0122] In an eleventh aspect of the present application, a communication system is provided, which includes a terminal device as in the first aspect, a terminal device as in the second aspect, or a terminal device as in the third aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0123] Figure 1 A schematic diagram of an application scenario proposed in an embodiment of the present application;

[0124] Figure 2 A schematic diagram of a scenario in which a terminal device switches from a serving cell to a candidate cell;

[0125] Figure 3 A schematic diagram of a process of switching a terminal device from a serving cell to a candidate cell;

[0126] Figure 4 A schematic diagram of an embodiment flow of a beam-based communication method proposed in an embodiment of the present application;

[0127] Figure 5A schematic diagram of another embodiment of a beam-based communication method in an embodiment of the present application;

[0128] Figure 6 A schematic diagram of a communication device provided in an embodiment of the present application;

[0129] Figure 7 Another schematic diagram of a communication device provided in an embodiment of the present application;

[0130] Figure 8 Another schematic diagram of a communication device provided in an embodiment of the present application;

[0131] Fig. 9 Another schematic diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0132] The terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged under appropriate circumstances. This is merely a way of distinguishing objects with the same properties when describing the embodiments of the present application. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, so that a process, method, system, product, or device that includes a series of units is not necessarily limited to those units, but may include other units that are not explicitly listed or inherent to these processes, methods, products, or devices.

[0133] The technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. In the description of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in the present application is only a description of the association relationship of associated objects, indicating that three relationships can exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the present application, "at least one" refers to one or more items, and "multiple items" refers to two or more items. "At least one of the following (items)" or similar expressions refers to any combination of these items, including any combination of single items (items) or plural items (items). For example, at least one of a, b, or c can be represented by: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0134] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as: Long Term Evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) system or NR and future sixth generation communication system, etc. For another example, the technical solutions of the embodiments of the present application can also be applied to open access network (openRAN, O-RAN or ORAN), cloud radio access network (cloud radio access network, CRAN), or wireless fidelity (WiFi) system, and the technical solutions of the embodiments of the present application can also be applied to communication systems in which two or more of the above systems are integrated.

[0135] The part operated by the operator in various communication systems can be called the operator network. The operator network can also be called the PLMN network, which is a network established and operated by the government or an operator approved by the government for the purpose of providing land mobile communication services to the public. It is mainly a public network where mobile network operators (MNO) provide mobile broadband access services to users. The operator network or PLMN network described in the embodiment of the present application can be a network that meets the requirements of the third generation partnership project (3rd generation partnership project, 3GPP) standards, referred to as the 3GPP network. Usually, the 3GPP network is operated by an operator, including but not limited to the fifth generation mobile communication (5th-generation, 5G) network (referred to as 5G network), the fourth generation mobile communication (4th-generation, 4G) network (referred to as 4G network) or the third generation mobile communication technology (3rd-generation, 3G) network (referred to as 3G network). It also includes the future 6G network. For the convenience of description, the operator network (such as the mobile network operator (mobile network operator, MNO) network) will be used as an example in the embodiment of the present application.

[0136] In order to facilitate understanding of the embodiments of this application, some application scenarios of this solution are introduced. Figure 1 , Figure 1 A schematic diagram of an application scenario proposed in an embodiment of the present application. In an optional implementation, the transmitting end involved in the embodiment of the present application may be a network device, and the receiving end may be a terminal device. In another optional implementation, the transmitting end involved in the embodiment of the present application may be a terminal device, and the receiving end may be a network device.

[0137] In the embodiments of the present application, the terminal device may also be referred to as user equipment (UE). The terminal device involved in the embodiments of the present application is a device with wireless transceiver functions, which can communicate with one or more core networks (CN) via the access network device in the network device. The terminal device may also be referred to as an access terminal, terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, wireless network equipment, user agent or user device, etc. The terminal device can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; it can also be deployed on the water (such as ships, etc.); it can also be deployed in the air (such as airplanes, balloons and satellites, etc.). The terminal device can be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a smart phone, a mobile phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device or other device connected to a wireless modem, a vehicle-mounted device, a wearable device, an unmanned aerial vehicle device or an Internet of Things, a terminal in the Internet of Vehicles, a terminal of any form in the fifth generation mobile communication (5G) network and future networks, a relay user device or a terminal in a future evolved public land mobile communication network (PLMN), etc., wherein the relay user device can be, for example, a 5G residential gateway (RG). For example, the terminal device can be a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. The embodiments of the present application are not limited to this. The terminal device can be widely used in various scenarios, such as virtual reality, augmented reality, industrial control, automatic driving, remote medical, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc.The terminal may be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a drone, a helicopter, an airplane, a ship, a robot, a mechanical arm, a smart home device, etc. The embodiments of the present application do not limit the device form of the terminal device.

[0138] The network device can be regarded as a sub-network of the operator network, and is an implementation system between the service node and the terminal device in the operator network. To access the operator network, the terminal device must first pass through the network device, and then connect to the service node of the operator network through the network device. The network device in the embodiment of the present application is a device that provides wireless communication functions for the terminal device, and can also be called an access network (AN) or a radio access network (RAN) node.

[0139] RAN nodes can be base stations, evolved NodeBs (eNodeBs), access points (APs), transmission reception points (TRPs), next generation NodeBs (gNBs), next generation base stations in 6th generation (6G) mobile communication systems, base stations in future mobile communication systems, or access nodes in WiFi systems. RAN nodes can be macro base stations, micro base stations, or indoor stations), relay nodes or donor nodes, or wireless controllers in CRAN scenarios. Optionally, RAN nodes can also be servers, wearable devices, vehicles, or on-board devices. For example, the access network equipment in vehicle to everything (V2X) technology can be a road side unit (RSU).

[0140] In another possible scenario, multiple RAN nodes collaborate to assist the terminal in achieving wireless access, and different RAN nodes respectively implement part of the functions of the base station. For example, the RAN node can be a centralized unit (CU), a distributed unit (DU), a CU-control plane (CP), a CU-user plane (UP), or a radio unit (RU). The CU and DU can be set separately, or can also be included in the same network element, such as a baseband unit (BBU). The RU can be included in a radio frequency device or a radio frequency unit, such as a remote radio unit (RRU), an active antenna unit (AAU) or a remote radio head (RRH).

[0141] In different systems, CU (or CU-CP and CU-UP), DU or RU may also have different names, but those skilled in the art can understand their meanings. For example, in the ORAN system, CU may also be called O-CU (open CU), DU may also be called O-DU, CU-CP may also be called O-CU-CP, CU-UP may also be called O-CU-UP, and RU may also be called O-RU. For the convenience of description, CU, CU-CP, CU-UP, DU and RU are described as examples in this application. Any unit of CU (or CU-CP, CU-UP), DU and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0142] A beam-based communication method provided in the present application can be applied to various communication systems, for example, the Internet of Things (IoT), narrowband Internet of Things (NB-IoT), long term evolution (LTE), fifth generation (5G) communication system, LTE and 5G hybrid architecture, 5G new radio (NR) system and new communication systems emerging in future communication development. The 5G communication system of the present application may include at least one of a non-standalone (NSA) 5G communication system and a standalone (SA) 5G communication system. The communication system may also be a public land mobile network (PLMN) network, a device-to-device (D2D) network, a machine-to-machine (M2M) network or other networks.

[0143] In addition, the embodiments of the present application may also be applicable to other future-oriented communication technologies, such as 6G, etc. The network architecture and service scenarios described in this application are intended to more clearly illustrate the technical solutions of this application, and do not constitute a limitation on the technical solutions provided by this application. A person of ordinary skill in the art will know that with the evolution of the network architecture and the emergence of new service scenarios, the technical solutions provided by this application are also applicable to similar technical problems.

[0144] Below, some technical concepts involved in the embodiments of the present application are introduced.

[0145] 1. Beam: A beam is a communication resource. A beam can be a wide beam, a narrow beam, or other types of beams. The technology used to form the beam can be beamforming technology or other technical means. Beamforming technology can specifically include digital beamforming technology, analog beamforming technology, and hybrid digital / analog beamforming technology. Different beams can be considered as different resources.

[0146] In the NR protocol, a beam can be called a spatial domain filter, a spatial filter, a spatial domain parameter, a spatial parameter, a spatial parameter, a spatial domain setting, a spatial setting, quasi-colocation (QCL) information, a QCL assumption, or a QCL indication, etc. The beam can be indicated by a TCI-state parameter or by a spatial relation parameter. Therefore, in this application, the beam can be replaced by a spatial domain filter, a spatial filter, a spatial domain parameter, a spatial parameter, a spatial setting, a spatial setting, QCL information, a QCL assumption, a QCL indication, a TCI-state (including uplink TCI-state, downlink TCI-state), or a spatial relation, etc. The above terms are also equivalent to each other. The beam can also be replaced by other terms representing the beam, which are not limited in this application.

[0147] The transmitter can send the same information or different information through different beams. Optionally, multiple beams with the same or similar communication characteristics can be regarded as one beam. A beam can include one or more antenna ports for transmitting data channels, control channels, and detection signals, etc. The uplink transmit beam can be indicated by any one of the spatial relationship, TCI-state, and SRS resources (indicating the transmit beam using the SRS). Therefore, the uplink transmit beam can also be replaced by an SRS resource.

[0148] A beam used to transmit a signal may be referred to as a transmission beam (Tx beam), a spatial domain transmission filter, a spatial transmission filter, a spatial domain transmission parameter, a spatial transmission parameter, a spatial domain transmission setting, or a spatial transmission setting.

[0149] A beam used to receive a signal may be referred to as a reception beam (Rx beam), a spatial domain reception filter, a spatial reception filter, a spatial domain reception parameter or a spatial reception parameter, a spatial domain reception setting, or a spatial reception setting.

[0150] For example, a transmit beam may refer to the distribution of signal strength in different directions of space after a signal is transmitted by an antenna, and a receive beam may refer to the distribution of signal strength in different directions of space of a wireless signal received from an antenna. It is understandable that one or more antenna ports forming a beam may also be regarded as an antenna port set.

[0151] When the transmitter uses low-frequency or medium-frequency bands, it can send signals omnidirectionally or at a wider angle. When using high-frequency bands, thanks to the smaller carrier wavelength of the high-frequency communication system, an antenna array consisting of many antenna elements can be arranged at the transmitter and receiver. The transmitter sends signals with a certain beamforming weight, so that the transmitted signal forms a beam with spatial directivity. At the same time, the antenna array is used at the receiver to receive the signal with a certain beamforming weight. This is beneficial to increase the received power of the signal at the receiver and combat path loss.

[0152] 2. Quasi-co-location (QCL): Quasi-co-location relationship is used to indicate that multiple resources have one or more identical or similar communication characteristics. For multiple resources with quasi-co-location relationship, the same or similar communication configuration can be adopted. For example, if two antenna ports have a quasi-co-location relationship, the large-scale characteristics of the channel for transmitting a symbol on one port can be inferred from the large-scale characteristics of the channel for transmitting a symbol on the other port. Large-scale characteristics may include: delay spread, average delay, Doppler spread, Doppler shift, average gain, receiving parameters, terminal device receiving beam number, transmit / receive channel correlation, receive arrival angle, receiver antenna spatial correlation, main arrival angle (Angel-of-Arrival, AoA), average arrival angle, AoA extension, etc. Specifically, the co-location indication is used to indicate whether at least two groups of antenna ports have a co-location relationship, including: the co-location indication is used to indicate whether the channel state information reference signals sent by at least two groups of antenna ports are from the same transmission point, or the co-location indication is used to indicate whether the channel state information reference signals sent by at least two groups of antenna ports are from the same beam group.

[0153] 3. Reference Signal: According to the Long Term Evolution LTE / NR protocol, at the physical layer, uplink communication includes the transmission of uplink physical channels and uplink signals. Uplink physical channels include random access channel (PRACH), uplink control channel (PUCCH), uplink data channel (PUSCH), etc. Uplink signals include channel sounding signal SRS, uplink control channel demodulation reference signal (PUCCH de-modulation reference signal, PUCCH-DMRS), uplink data channel demodulation reference signal PUSCH-DMRS, uplink phase noise tracking signal (PTRS), uplink positioning signal (uplink positioning RS), etc. Downlink communication includes the transmission of downlink physical channels and downlink signals. The downlink physical channels include physical broadcast channel (PBCH), physical downlink control channel (PDCCH), physical downlink shared channel (PDSCH), etc. The downlink signals include primary synchronization signal (PSS) / secondary synchronization signal (SSS), downlink control channel demodulation reference signal PDCCH-DMRS, downlink data channel demodulation reference signal PDSCH-DMRS, phase noise tracking signal PTRS, channel status information reference signal (CSI-RS), cell signal (CRS) (NR does not have), tracking reference signal (TRS), LTE / NR positioning signal (positioning RS), etc.

[0154] Regarding TRS, TRS can be considered as a CSI-RS resource set (resource set), and TRS is a CSI-RS resource set including one or more CSI-RS resources.

[0155] 4. Transmission Configuration Indicator (TCI): It can also be called TCI-State. The communication protocol stipulates that QCL is configured through TCI state. The parameters of TCI state are used to configure the quasi-co-location relationship between one or two downlink reference signals and the DMRS of PDSCH. The downlink control information (DCI) may include a TCI field, which is a field in DCI used to indicate the quasi-co-location of the PDSCH antenna port. In the current 3GPP standard, the TCI state is commonly used to indicate the beam.

[0156] TCI is configured by the network device for the terminal device through an RRC message, and is called TCI state in the configuration signaling. After the network device configures the TCI state for the terminal device through an RRC message. The network device can send a media access control layer control element (MAC CE) to the terminal device, and the MAC is used to activate one or more TCI states in the TCI state configured by the network device for the terminal device. Optionally, the network device can further send a DCI to the terminal device, and the DCI is used to indicate a TCI state in the TCI state activated by the MAC CE.

[0157] The TCI state includes one or two QCL relationships, which characterize a certain consistency relationship between the signal / channel to be received and a previously known reference signal. If a QCL relationship exists, the terminal device can inherit the receiving or sending parameters when a reference signal was previously received to receive or send the upcoming signal / channel. Each TCI state corresponds to a beam. The terminal device can communicate through the beam.

[0158] The following describes the configuration, activation and indication of TCI status.

[0159] TCI state configuration: The network device configures multiple TCI states to the terminal device through Radio Resource Controller (RRC) signaling. These TCI states all include a QCL-Info of type D. The network device can also configure TCI-states that do not include QCL-info of type D, but these TCI states are not used for data transmission beam indication, so they are not further explained here.

[0160] TCI state activation: After the network device configures multiple TCI states, it needs to activate up to 8 of them through MAC-CE. Taking 8 as an example, these 8 TCI states correspond one-to-one to the 8 values ​​of the TCI field in the DCI. That is, which 8 TCI states the 8 values ​​of the TCI field of the DCI correspond to is determined by the media access control layer control element (MAC CE).

[0161] TCI state indication: The network device indicates a specific TCI-state through the TCI field in the DCI. For example, the value of the TCI field in the DCI sent by the network device to the terminal device is 000, indicating that the data transmission beam adopts the TCI state corresponding to 000. The reference signal contained in the QCL-Info of type D in the TCI state is the channel state information-reference signal (CSI-RS) with an index of #1, indicating that the beam used for data transmission is the same as the receiving beam corresponding to the CSI-RS with an index of #1. The receiving beam corresponding to the CSI-RS with an index of #1 can be determined through the beam measurement process and is known to the terminal device. Therefore, through the specific value of the TCI field, the terminal device can determine the beam corresponding to the data transmission beam, and thus use the corresponding beam to send or receive data.

[0162] It should be noted that the two descriptions of TCI-state and TCI state in this article can be interchangeable.

[0163] The QCL types regarding TCI include: QCL type A (QCL-Type A, or type A, or type A), the characteristics of QCL type A include Doppler shift, Doppler spread, average delay, and delay spread, etc. QCL type A is used to obtain channel estimation information;

[0164] QCL type B (QCL-TypeB, or type B, or typeB), the characteristics of QCL type B include Doppler shift and Doppler spread, etc. QCL type B is used to obtain channel estimation information;

[0165] QCL type C (QCL-Type C, or type C, or type C), the characteristics of QCL type C include average delay and delay spread, etc. QCL type C is used to obtain measurement information such as reference signal received power (RSRP);

[0166] QCL type D (QCL-TypeD, or type D, or, typeD), the characteristics of QCL type D include spatial reception (Rx) parameters, etc. QCL type D is used to assist UE beamforming.

[0167] The QCL information about the TCI state (also referred to as QCL configuration, or QCL configuration information, which is not limited in this application) is specifically indicated by the TCI state information element (TCI-State information element). A maximum of two QCL information (QCL-Info) can be indicated in the "TCI-Stateinformation element", for example: "qcl-Type1 QCL-Info, qcl-Type2 QCL-Info". The QCL information further includes the configuration information of the reference signal (the configuration information of the reference signal may also be referred to as the relevant information of the reference signal, which is not limited in this application) and the type configuration of the QCL information (qcl-Type), wherein the configuration information of the reference signal is, for example, "referenceSignal CHOICE{csi-rs NZP-CSI-RS-ResourceId, ssb SSB-Index}", and the type configuration of the QCL information is, for example: "qcl-Type ENUMERATED{typeA, typeB, typeC, typeD}".

[0168] Regarding the configuration information of the reference signal in the QCL information, the configuration information of TRS is used as an example below. TRS is a special CSI-RS resource set, and the configuration information of TRS can also be understood as the configuration information of the CSI-RS resource set, such as "NZP-CSI-RS-ResourceSet information element". "NZP-CSI-RS-ResourceSet" includes TRS information (trs-info), and the TRS information is configured as "true".

[0169] The configuration information of TRS may include configuration information of multiple CSI-RS resources (also referred to as configuration information of CSI-RS), such as "NZP-CSI-RS-Resource information element". The configuration information of CSI-RS may also include index information of TCI state (or identifier of TCI state) "TCI-StateId". For example, the configuration information of CSI-RS "NZP-CSI-RS-Resource information element" includes "qcl-InfoPeriodicCSI-RS TCI-StateId". In other words, the QCL information of the TCI state indicates that the TCI state is associated with the reference signal, and the reference signal serves as the source reference signal (source RS) of the TCI state. The TCI state corresponding to the reference signal may be recorded in the configuration information of the reference signal.

[0170] 5. Common beam: Currently, each channel uses a separate beam indication. Each channel has its own corresponding beam. In this application, a common beam is defined, which is used for multiple uplink and / or downlink channels at the same time.

[0171] Common beam: the same beam used by one or more channels, one or more channels, one or more reference signals, and / or one or more reference signals. Channels include but are not limited to at least one of: PDCCH, PDSCH, PUCCH, PUSCH, PRACH. Reference signals include but are not limited to at least one of: synchronization signal block (SSB or SS / PBCH), CSI-RS, DMRS, PTRS, TRS, SRS, etc. Among them, CSI-RS can be CSI-RS configured for beam management, or it can be CSI-RS configured for channel state information acquisition (for CSI).

[0172] Joint common beam: used for transmission of at least one uplink channel or at least one reference signal and at least one downlink channel or at least one reference signal. For example, PDCCH, PDSCH, PUCCH and PUSCH. Joint common beam can also be called uplink and downlink common beam.

[0173] Uplink common beam: used for transmission of multiple uplink channels at the same time, and / or, used for transmission of multiple uplink channels at the same time, and / or, used for transmission of one or more uplink reference signals at the same time, for example, PUCCH, PUSCH and SRS.

[0174] Downlink common beam: used for transmission of multiple downlink channels at the same time, and / or, used for transmission of multiple downlink channels at the same time, and / or, used for transmission of one or more downlink reference signals at the same time, such as PDCCH, PDSCH and CSI-RS.

[0175] The form of common beam: the common beam can be a newly defined structure (different from the existing TCI-state). For example, the common beam includes relevant information of the beam indication, including but not limited to one or more of the following: common beam identifier (identifier, ID), logical cell identifier (cell ID), physical cell identifier, partial bandwidth identifier, reference signal resources for determining the beam, QCL type, uplink power control related parameters (such as path loss measurement reference signal resources, p0, closed loop index (closedLoopIndex)), path loss reference signal identifier.

[0176] Application scope of common beam: Common beam can be cell-level, that is, one common beam is used for transmission of multiple channels in one cell. Common beam can be BWP-level, used for transmission of multiple beams in one BWP. Common beam can also be cross-cell, that is, used for transmission of multiple channels in multiple cells. The multiple cells can be multiple cells in one frequency band. The multiple cells can also be multiple cells across frequency bands.

[0177] Exemplarily, the common beam may also be referred to as a unified transmission configuration indicator (UTCI).

[0178] See also Figure 2 , Figure 2 A schematic diagram of a scenario in which a terminal device switches from a serving cell to a candidate cell. It is understandable that this scenario may also include multiple network devices and multiple terminal devices. Take a terminal device switching from a serving cell to a candidate cell as an example for illustration. The candidate cell may also be referred to as a neighbor cell (or neighboring cell), and the candidate cell may be understood as other cells near the serving cell. After the terminal device moves from the serving cell to the edge of the cell, as the signal quality of the serving cell deteriorates, it is necessary to switch from the serving cell to the candidate cell, that is, the communication service provided by the serving cell is switched to the communication service provided by the candidate cell. It should be noted that each cell can be configured with multiple carriers (CC), and the carrier may also be referred to as a serving cell.

[0179] by Figure 2 For example, the following describes the specific process of switching from a serving cell to a candidate cell. Figure 3 , Figure 3 The present invention is a flow chart of a terminal device switching from a serving cell to a candidate cell. Specifically, it includes:

[0180] A1. The terminal device obtains configuration information. The configuration information includes configuration information of the TCI state and configuration information of related reference signals. The configuration information comes from the first network device, which is a network device in the service cell. Since the terminal device may be configured with multiple candidate cell configurations, before determining the target candidate cell to which the terminal device is to switch, the terminal device will parse the configurations of all candidate cells, which will bring a huge computational burden. Therefore, after receiving the configuration information, the terminal device may not parse and cache the configuration information, and parse the configuration information after receiving the switching command of step A2.

[0181] The configuration information may be carried in an RRC message.

[0182] A2. The first network device sends a switching command to the terminal device. The switching command indicates a TCI state, and the terminal device determines the common beam after switching according to the TCI state indicated by the switching command. The switching command can be carried in a MAC CE message.

[0183] A3. The terminal device determines the reference signal (CSI-RS / TRS) corresponding to the TCI state from the configuration information according to the switching command. In step A3, after receiving the switching command, the terminal device parses the QCL information of the TCI state from the configuration information, and then determines the reference signal identifier corresponding to the TCI state, such as the identifier of TRS and CSI-RS. Then the terminal device further determines the reference signal according to the identifier of the reference signal, such as the configuration information corresponding to TRS and the configuration information of CSI-RS. Among them, the terminal device determines the TCI corresponding to TRS according to the configuration information of TRS. The TCI corresponding to TRS is the beam information of the received TRS, which is configured in the configuration information of TRS, and the TCI is different from the TCI indicated in the switching command. The TCI state of the received TRS includes the SSB index.

[0184] A4. The terminal device tracks and measures the SSB. After the terminal device determines the configuration information of the TRS, the terminal device needs to track and measure the TRS. Before measuring the TRS, the terminal device needs to first track and measure the SSB corresponding to the TRS to determine the beam. According to the measurement result of the SSB, the corresponding TRS is measured. Therefore, the terminal device needs to measure the SSB first.

[0185] A5. After the terminal device obtains the measurement result of SSB, the terminal device tracks and measures TRS based on the measurement result of SSB.

[0186] A6. The terminal device activates the TCI indicated by the switching command according to the measurement result of the TRS.

[0187] A7. The terminal device and the second network device use the activated TCI as a common beam transmission signal, and the second network device is a network device of the candidate cell.

[0188] Through the above process, the terminal device activates the TCI state, which is used to transmit signals with the candidate cell to switch the terminal device from the serving cell to the candidate cell. The applicant found that the terminal device can only parse the configuration information related to the candidate cell after receiving the switching command, and then measure the SSB and TRS corresponding to the TCI state of the candidate cell, and finally activate the TCI state according to the measurement results. The above process has a large delay, resulting in a long suspension time of the terminal device communication, which reduces the communication quality.

[0189] Based on this, an embodiment of the present application proposes a beam-based communication method. In a scenario where a terminal device switches from a serving cell to a candidate cell, the first TCI state that needs to be activated can be determined based on the received first indication information. Then, the first synchronization signal block SSB is determined based on the first TCI state, and the first SSB is pre-measured to obtain a first measurement result. After the terminal device receives the switching command, it measures the reference signal corresponding to the second TCI state based on the first measurement result to obtain a second measurement result. Based on the second measurement result, the second TCI state is activated, and the activated second TCI state is used to transmit data. Through the first indication information, the SSB associated with the TCI state is pre-measured to achieve rapid activation of the TCI state. Reduce the communication interruption time of the terminal device and improve the communication quality of the terminal device.

[0190] The following is an introduction to the embodiments of the present application in conjunction with the accompanying drawings. Figure 4 , Figure 4 A beam-based communication method according to an embodiment of the present application is provided. The beam-based communication method according to an embodiment of the present application includes:

[0191] S1. Obtain configuration information.

[0192] In step S1, the terminal device obtains configuration information, which is configuration information related to the candidate cell and the TCI state. For example, the configuration information includes: quasi-co-location QCL information of the TCI state of the candidate cell and / or relevant information of the CSI-RS of the candidate cell. The relevant information of the CSI-RS of the candidate cell specifically includes the configuration information of the CSI-RS, and the configuration information is used to determine the time domain and frequency domain resource configuration of the CSI-RS. The configuration information may also include the configuration information of the TRS of the candidate cell, including the TCI state identifier required to receive the TRS.

[0193] Regarding the candidate cell, the candidate cell refers to a candidate of the handover target cell, and the candidate cell may include multiple cells. The candidate cell may be a cell geographically adjacent to the current serving cell, or may be other cells, which is not limited in the embodiments of the present application.

[0194] After the terminal device receives the configuration information, the terminal device may parse the configuration information in advance. For example, the terminal device parses the configuration information in advance before receiving the first indication information of step S2. For another example, after receiving the first indication information of step S2, the terminal device parses the configuration information in response to the first indication information.

[0195] The configuration information may be carried in an RRC message (or RRC signaling). The configuration information may also be carried in other messages or signaling, which is not limited in this application.

[0196] The above configuration information is referred to as the first configuration information, and the other configuration information of the candidate cell is referred to as the second configuration information, and the second configuration information includes relevant configuration information such as the uplink and downlink physical channels of the candidate cell. The second configuration information is, for example, the cell group configuration information (cellgroupconfig) of the candidate cell. The second configuration information is applied by the terminal device only after the terminal device receives a switching command to switch to the candidate cell, or the second configuration information is parsed and applied.

[0197] In a possible implementation, the first configuration information is carried in a first information element, and the second configuration information is carried in a second information element. The RRC message includes a first information element and a second information element. After receiving the RRC message, the terminal device extracts the first information element and the second information element from the RRC message. For the first information element, the terminal device parses the first information element in advance and validates the first configuration information included in the first information element; for the second information element, the terminal device parses the second information element after receiving the corresponding switching command, and then validates the second configuration information included in the second information element in response to the switching command.

[0198] In another possible implementation, the above-mentioned configuration information related to the TCI status is carried in the first sub-configuration information, and other configuration information is carried in the second sub-configuration information. The first sub-configuration information and the second sub-configuration information can be sent in the same message or in different messages. The embodiment of the present application does not limit this.

[0199] It should be noted that the execution steps of the network device in the embodiment of the present application can be executed by a base station, or by any one or more network elements in O-CU-CP, O-CU-UP, O-DU, or O-RU, and the embodiment of the present application is not limited to this.

[0200] S2. The first network device sends first indication information to the terminal device, and the first indication information is used to activate the TCI state of the candidate cell.

[0201] In step S2, the first network device of the serving cell sends a first indication message to the terminal device. The first indication message may also be referred to as TCI activation signaling or TCI activation message, which is not limited in the embodiments of the present application. The first indication message is used to activate the TCI state of the candidate cell. The TCI state of the activated candidate cell includes a first TCI state, and the first TCI state includes one or more TCI states. In other words, the candidate cell may include a configuration of multiple TCI states, and the first indication message is used to activate one or more TCI states of the multiple TCI states. The TCI state of the activated candidate cell is called the first TCI state. Regarding the first TCI state, it may also be referred to as a semi-activated TCI state.

[0202] In a possible implementation, the first indication information can also be used to deactivate the TCI state of the candidate cell. Specifically, the first indication information can explicitly include an "activation / deactivation" field, which can be used to identify that the first indication information is used to activate or deactivate the TCI state, that is, all TCI state identifiers included in the same first indication information are activated or deactivated according to the "activation / deactivation" field, such as a 1-bit indication, where '1' indicates activation and '0 indicates deactivation'. Or this field can be used to identify the TCI state for activation or deactivation corresponding to each TCI state in the first indication information. For example, if the first indication information includes 8 TCI state identifiers, the "activation / deactivation" field may include 8 bits, where the value of each bit '1' indicates activation of the corresponding TCI state, and '0 indicates deactivation' of the corresponding TCI state. The "activation / deactivation" field corresponds to the TCI state identifier in order, for example, the leftmost or rightmost in the field corresponds to the first TCI state identifier, and so on.

[0203] Exemplarily, the candidate cells include: cell #1, cell #2, cell #3, cell #4 and cell #5. The first indication information in step S2 is used to activate the TCI status of cell #1, the TCI status of cell #2, the TCI status of cell #3, the TCI status of cell #4 and the TCI status of cell #5. The first indication information can also be used to activate the TCI status of some candidate cells, for example, activating the TCI status of cell #1 and the TCI status of cell #2. It can be understood that the first indication information can also be used to activate any one or more TCI states in the cell, and the embodiments of the present application are not limited to this.

[0204] The first indication information may be carried in a variety of messages. For example, the first indication information may be carried in a media access control layer control element (MAC CE) message. The first indication information may also be carried in downlink control information (DCI).

[0205] In a possible implementation, the first TCI state includes the TCI state of a common beam, and the TCI state of a common beam is also referred to as a UTCI (unified TCI) state. The type of QCL information included in the first TCI state may be type A and / or type D, and the source reference signal (source RS) of the first TCI state includes a TRS or a CSI-RS. Specifically, the reference signal in the QCL information of the first TCI state includes at least one CSI-RS, for example, the QCL information of the first TCI state includes a first CSI-RS and / or a second CSI-RS. For another example, the QCL information of the first TCI state includes a first TRS. The at least one CSI-RS is a CSI-RS of a candidate cell, for example, the first CSI-RS and / or the second CSI-RS are CSI-RS of a candidate cell.

[0206] Exemplarily, the first TCI state includes TCI state #1, TCI state #2, TCI state #3, TCI state #4, and TCI state #5.

[0207] In a possible example, the types of QCL information in TCI state #1 are type A and type D, the types of QCL information in TCI state #2 are type A and type D, the types of QCL information in TCI state #3 are type A and type D, the types of QCL information in TCI state #4 are type A and type D, and the types of QCL information in TCI state #5 are type A and type D.

[0208] In another possible implementation, the first TCI state further includes a fourth TCI state, and the type of QCL information of the fourth TCI state is type C and / or type D. The source reference signal of the fourth TCI state includes a synchronization signal block (SSB or SS / PBCH).

[0209] In another possible implementation, the first TCI state also includes a TCI state in which the type of QCL information is type B and / or type C. The embodiment of the present application does not limit the type of QCL information in the first TCI state.

[0210] It can be understood that in the embodiment of the present application, the "type of QCL information in the TCI state" can also be expressed as the "type of QCL information in the TCI state configuration", and the present application does not impose any restrictions on this.

[0211] S3. According to the first indication information, measure the first SSB to obtain a first measurement result.

[0212] In step S3, after determining the first TCI state according to the first indication information, the first SSB is further measured to obtain a first measurement result.

[0213] Specifically, the first SSB has a QCL relationship with at least one CSI-RS in the QCL information of the first TCI state, the first SSB is the SSB of the candidate cell, and the CSI-RS is the CSI-RS resource of the candidate cell. It can be understood that when the first TCI state includes multiple TCI states, the first SSB refers to multiple SSBs.

[0214] Next, how to determine the first SSB is introduced according to the type of QCL information in the first TCI state.

[0215] In a possible implementation, when the type of the QCL information of the first TCI state is type A and / or type D, at least one CSI-RS corresponding to the first TCI state is determined according to the QCL information of the first TCI state. Then, the terminal device determines the TCI state corresponding to the CSI-RS according to the configuration information of the at least one CSI-RS. For the convenience of description, the TCI state is referred to as the third TCI state. The configuration information of the CSI-RS may be the configuration information acquired by the terminal device in step S1. The configuration information of the at least one CSI-RS includes identification information of the third TCI state, and the third TCI state is used to determine the receiving parameters of the reference signal corresponding to the first TCI state. The receiving parameters include, but are not limited to, time offset compensation, frequency offset compensation, and / or receiving beam, etc. Since the QCL information of the third TCI state includes the index information of the first SSB, the terminal device determines the first SSB according to the index information of the first SSB in the QCL information of the third TCI state. The QCL type of the third TCI state is type C and / or type D.

[0216] In another possible implementation, when the first TCI state also includes a fourth TCI state, the QCL information of the fourth TCI state is determined according to the first indication information. Then, according to the QCL information of the fourth TCI state, the first SSB is determined, wherein the QCL information of the fourth TCI state includes the index information of the first SSB.

[0217] After the terminal device determines the first SSB, the terminal device measures the first SSB to obtain a first measurement result, which is as follows:

[0218] The clock offset compensation and / or frequency domain offset compensation and / or receiving beam determined by measuring the first SSB. The receiving beam may refer to the spatial filter used by the terminal device to receive the first SSB, or the receiving spatial filter parameters (Rxspatial filter parameters) for receiving other signals.

[0219] Exemplarily, when the first SSB includes multiple SSBs, the terminal device measures multiple first measurement results corresponding to the multiple SSBs. Then, the terminal device associates the multiple first measurement results with the corresponding first TCI states and stores them. For example, as shown in Table 1:

[0220] TCI Status SSB First measurement result TCI Status #1 SSB#1 First measurement result #1 TCI Status #2 SSB#2 First measurement result #2 TCI Status #3 SSB#3 First measurement result #3 TCI Status #4 SSB#4 First measurement result #4

[0221] Table 1

[0222] S4. Receive a switching command, where the switching command is used to indicate a second TCI state.

[0223] In step S4, after step S3, the terminal device receives a switching command sent by the first network device, and the switching command instructs the terminal device to switch from the serving cell to the candidate cell.

[0224] Exemplarily, if the first indication information in step S2 is used to activate the TCI status of multiple candidate cells, the switching command in step S4 instructs the terminal device to switch from the serving cell to a target cell among the multiple candidate cells. For example, the candidate cells include: cell #1, cell #2, cell #3, cell #4, and cell #5. The first indication information in step S2 is used to activate the TCI status of cell #1, the TCI status of cell #2, the TCI status of cell #3, the TCI status of cell #4, and the TCI status of cell #5. The switching command in step S4 is used to instruct the terminal device to switch from the serving cell to cell #2, which serves as the target cell. The second TCI state indicated by the switching command belongs to cell #2.

[0225] The switching command is also used to indicate a second TCI state, which belongs to the first TCI state. For example, the first TCI state includes TCI state #1, TCI state #2, TCI state #3, TCI state #4 and TCI state #5. The second TCI state is TCI state #3.

[0226] Exemplarily, the type of QCL information about the second TCI state may be a TCI state of type A and / or type D, and the source reference signal of the second TCI state includes a CSI-RS or a TRS.

[0227] Exemplarily, the handover command is carried in a media access control layer control element MAC CE message.

[0228] S5. In response to the switching command, measure a reference signal corresponding to the second TCI state according to the first measurement result to obtain a second measurement result.

[0229] In step S5, in response to the switching command, according to the second TCI state indicated by the switching command, a first measurement result corresponding to the second TCI state is determined. Then, according to the first measurement result (corresponding to the second TCI state), a reference signal corresponding to the second TCI state is measured to obtain a second measurement result, as follows:

[0230] According to the clock offset compensation and / or frequency domain offset compensation and / or receiving beam determined by measuring the first SSB, a reference signal corresponding to the second TCI state is received. The reference signal may be a TRS signal or a CSI-RS signal.

[0231] Optionally, before step S5, the terminal device determines the TCI corresponding to the first SSB as a default beam based on the first measurement result, and the default beam is used to transmit signals with the switched serving cell, and the switched serving cell belongs to the candidate cell. By using the default beam to transmit signals, the communication terminal time of the terminal device is reduced and the communication quality of the terminal device is improved.

[0232] Optionally, the TCI corresponding to the reference signal in the first TCI state is not allowed to be indicated by a switching command, or the TCI corresponding to the reference signal in the first TCI state is not allowed to be used for data transmission after receiving the switching command. The TCI corresponding to the reference signal in the first TCI state is not allowed to be indicated by a switching command, which can also be understood as: the TCI indicated by the switching command does not include the TCI corresponding to the reference signal in the first TCI state, and the TCI activated by the switching command is used for data transmission. The reference signal includes but is not limited to: TRS or CSI-RS.

[0233] S6. Activate the second TCI state according to the second measurement result.

[0234] In step S6, after the terminal device obtains the second measurement result through measurement, the second TCI state is activated according to the second measurement result. The activated second TCI state is used to transmit signals with the serving cell after the handover.

[0235] In an embodiment of the present application, in a scenario where a terminal device switches from a serving cell to a candidate cell, the first TCI state that needs to be activated can be determined based on the received first indication information. Then, the first synchronization signal block SSB is determined based on the first TCI state, and the first SSB is pre-measured to obtain a first measurement result. After the terminal device receives the switching command, the reference signal corresponding to the second TCI state is measured based on the first measurement result to obtain a second measurement result. Based on the second measurement result, the second TCI state is activated, and the activated second TCI state is used to transmit data. Through the first indication information, the SSB associated with the TCI state is pre-measured to achieve rapid activation of the TCI state. Reduce the communication interruption time of the terminal device and improve the communication quality of the terminal device.

[0236] In combination with the above-mentioned embodiment, the beam-based communication method proposed in the embodiment of the present application can also be used to determine a default beam, which is used for the terminal device to transmit signals to the serving cell after switching. Figure 5 , Figure 5 A beam-based communication method according to an embodiment of the present application is provided in the flowchart of another embodiment of the present application. A beam-based communication method according to an embodiment of the present application further includes:

[0237] F1. The terminal device receives a switching command from the network device.

[0238] In step F1, the handover command instructs the terminal device to handover from the serving cell to the candidate cell. The network device is the network device of the serving cell.

[0239] Exemplarily, the handover command is carried in a media access control layer control element MAC CE message.

[0240] There are many possible ways to switch commands, which are described below:

[0241] 1. The timing advance (TA) is not indicated in the handover command.

[0242] 2. The transmission configuration indication TCI is not indicated in the handover command. The handover command does not indicate TCI, including the handover command does not explicitly indicate TCI.

[0243] 3. TCI is indicated in the switching command.

[0244] 4. Indicate TA in the switching command.

[0245] F2. When any one or more of the first conditions are met, the terminal device determines a default beam, and the default beam is used to transmit signals with the switched service cell, and the switched service cell belongs to a candidate cell.

[0246] In step F2, after receiving the handover command, the terminal device detects whether the first condition is met according to the handover command. When any one or more of the first conditions are met, the terminal device determines a default beam, which is used to transmit signals with the switched serving cell, and the switched serving cell belongs to the candidate cell.

[0247] Specifically, the first condition includes: the transmission configuration indication TCI is not indicated in the handover command, and the terminal device determines the TA according to the measurement result of the downlink reference signal;

[0248] Alternatively, if the timing advance TA is not indicated in the switching command, the terminal device determines the TA based on the measurement result of the downlink reference signal;

[0249] Alternatively, the TA is indicated in the handover command, and the terminal device determines that the TA of the candidate cell is the same as the TA of the serving cell;

[0250] Alternatively, the TA is indicated in the handover command, and the terminal device determines that the TA of the candidate cell is 0;

[0251] Or, the TCI indicated in the switching command is not activated in advance;

[0252] Alternatively, the source reference signal of the TCI indicated in the switching command includes a channel state information reference signal CSI-RS, and the terminal device does not measure the CSI-RS before receiving the switching command;

[0253] Alternatively, the TCI is indicated in the switching command, and the terminal device feeds back a hybrid automatic repeat request response HARQ-ACK according to the switching command, and the time when the HARQ-ACK is fed back does not reach the beam effective time point;

[0254] Alternatively, the serving cell includes a primary cell (PCell) and at least one secondary cell (SCell), or the candidate cell includes a primary cell and at least one secondary cell, and the primary cell and the secondary cell are in the same timing advance group (TAG).

[0255] The terminal device determines the TA based on the measurement result of the downlink reference signal, including: before the terminal device switches from the serving cell to the candidate cell, the network device of the serving cell configures the terminal device. The specific configuration information includes but is not limited to: the terminal device calculates the timing advance based on the time difference between the measured SSB arrival time of the serving cell and the measured SSB arrival time of the candidate cell. According to the configured information, the terminal device calculates the timing advance based on the time difference between the two SSB arrival times.

[0256] When the terminal device determines that any one or more of the first conditions are met, the terminal device determines a default beam. The specific method for determining the default beam is as follows:

[0257] In a possible implementation, the terminal device determines the second synchronization signal block SSB as the default beam, the second SSB is the SSB of the candidate cell, the second SSB is used to measure the TA of the candidate cell, or the second SSB has a quasi-co-location QCL relationship with a reference signal for measuring the TA of the candidate cell. Specifically, the terminal device determines the second SSB as the default beam, including:

[0258] In a possible implementation, the first condition is that the source reference signal indicating TCI in the switching command includes a channel state information reference signal CSI-RS, and the terminal device has not measured the CSI-RS before receiving the switching command. And the switching command indicates TA, and the terminal device determines that the TA of the candidate cell is 0. At this time, the terminal device uses the second SSB that has a QCL relationship with the CSI-RS as the default beam. Or the terminal device receives the beam of the second SSB as the default beam, and the second SSB is the QCL reference source signal in the TCI configuration of the CSI-RS. In a possible implementation, the first condition is that the source reference signal indicating TCI in the switching command includes a channel state information reference signal CSI-RS, and the terminal device has not measured the CSI-RS before receiving the switching command. And the switching command indicates TA, and the terminal device determines the random access resources and sends the preamble code based on the second SSB of the candidate cell before switching, and the random access is triggered by the serving cell sending a PDCCH command. At this time, the terminal device uses the second SSB of the candidate cell for random access triggered by the PDCCH of the serving cell before switching as the default beam, and the candidate cell for random access triggered by the PDCCH is the target cell indicated by the switching command.

[0259] In a possible implementation, the first condition is that the source reference signal indicating TCI in the switching command includes a channel state information reference signal CSI-RS or TRS, and the terminal device does not measure the CSI-RS or TRS before receiving the switching command. At this time, the terminal device uses the second SSB having a QCL relationship with the CSI-RS or TRS as the default beam. The QCL type may be Type-D. Or the terminal device uses the beam receiving the second SSB as the default beam, and the second SSB is the QCL reference source signal in the TCI configuration of the CSI-RS.

[0260] In a possible implementation, the first condition is that TCI is not indicated in the switching command. If the terminal device determines TA based on the measurement result of the arrival time difference between the downlink reference signal of the candidate cell and the downlink reference signal of the serving cell before the switching command, the terminal device will receive the beam of the downlink reference signal of the candidate cell as the default beam. The downlink reference signal of the candidate cell can be a second SSB, CSI-RS, or other types of reference signals, which is not limited in the embodiments of the present application.

[0261] In one possible implementation, the first condition is that TCI is not indicated in the handover command. If the terminal device determines the random access resource based on the second SSB of the candidate cell and sends a preamble before the handover command, the random access is triggered by the PDCCH command sent by the serving cell. At this time, the terminal device uses the second SSB of the candidate cell for random access triggered by the PDCCH of the serving cell before the handover as the default beam, and the candidate cell for random access triggered by the PDCCH is the target cell indicated by the handover command.

[0262] Optionally, the second SSB is the first SSB in the first SSB set, the first SSB set includes multiple SSBs, and the first SSB set is used to measure the TA of the candidate cell.

[0263] Optionally, the second SSB is the SSB of the candidate cell most recently reported by the terminal device to the network device.

[0264] In another possible implementation, the terminal device determines the fifth TCI state indicated by the switching command according to the switching command; the terminal device determines the first reference signal as the default beam, or the terminal device determines the synchronization signal block SSB associated with the first reference signal as the default beam, and the first reference signal is the reference signal indicated by the quasi-co-location QCL information of the fifth TCI state. The type of the QCL information of the fifth TCI state may be type D. The first reference signal includes a CSI-RS or a TRS.

[0265] In another possible implementation, the terminal device determines the SSB with the largest reference signal receiving power from the synchronization signal blocks SSB of the candidate cells reported by the terminal device to the network device; the terminal device determines the SSB with the largest reference signal receiving power as the default beam.

[0266] In another possible implementation, the terminal device determines to measure the synchronization signal block SSB of the TA of the primary cell as the default beam.

[0267] Optionally, the default beam is used for transmitting signals in the primary cell, and the default beam is also used for transmitting signals in the secondary cell; the primary cell and the secondary cell are configured in a first set, and the first set is used to configure multiple cells to update beams according to at least one beam indication. Exemplarily, the first set may be the cells indicated by the list of simultaneously updated beams "simultaneousUTCI-Updatelist".

[0268] In another possible implementation, the terminal device obtains the TA of the target cell among the multiple cells indicated by the first set, and the target cell is any cell indicated by the first set; the terminal device determines a third synchronization signal block SSB according to the TA of the target cell, and the third SSB is used to measure the TA of the target cell, and the third SSB is the SSB of the candidate cell; the terminal device determines the third SSB as the default beam for any one or more cells in the first set.

[0269] Furthermore, the terminal device may also select a corresponding method to determine the default beam according to the first condition that is satisfied. Specifically, as follows:

[0270] In a possible implementation, when one or more of the following first conditions are met, the terminal device determines the default beam, including: the first condition includes: the transmission configuration indication TCI is not indicated in the handover command, and the terminal device determines the TA according to the measurement result of the downlink reference signal; or, the timing advance TA is not indicated in the handover command, and the terminal device determines the TA according to the measurement result of the downlink reference signal;

[0271] The terminal device determines a default beam, including: the terminal device determines a second synchronization signal block SSB as the default beam, the second SSB is the SSB of the candidate cell, the second SSB is used to measure the TA of the candidate cell, or the second SSB has a quasi-co-site QCL relationship with a reference signal for measuring the TA of the candidate cell.

[0272] Optionally, the second SSB is the first SSB in the first SSB set, the first SSB set includes multiple SSBs, and the first SSB set is used to measure the TA of the candidate cell.

[0273] Optionally, the second SSB is the SSB of the candidate cell most recently reported by the terminal device to the network device.

[0274] In another possible implementation, when one or more of the following first conditions are met, the terminal device determines the default beam, including: the first condition includes: the TA is indicated in the handover command, and the terminal device determines that the TA of the candidate cell is the same as the TA of the serving cell; or, the TA is indicated in the handover command, and the terminal device determines that the TA of the candidate cell is 0;

[0275] The terminal device determines a default beam, including: the terminal device determines the fifth TCI state indicated by the switching command according to the switching command; the terminal device determines the first reference signal as the default beam, or the terminal device determines the synchronization signal block SSB associated with the first reference signal as the default beam, and the first reference signal is the reference signal indicated by the quasi-co-site QCL information of the fifth TCI state.

[0276] Optionally, the type of QCL information of the fifth TCI state is type D; the first reference signal is a channel state information reference signal CSI-RS.

[0277] In another possible implementation, when one or more of the following first conditions are met, the terminal device determines the default beam, including: the first condition includes: the TA is indicated in the handover command, and the terminal device determines that the TA of the candidate cell is the same as the TA of the serving cell; or, the TA is indicated in the handover command, and the terminal device determines that the TA of the candidate cell is 0;

[0278] The terminal device determines a default beam, including: the terminal device determines an SSB with the largest reference signal receiving power from the synchronization signal blocks SSB of the candidate cells reported by the terminal device to the network device; the terminal device determines the SSB with the largest reference signal receiving power as the default beam.

[0279] In another possible implementation, the first condition further includes: the serving cell includes a primary cell and at least one secondary cell, or the candidate cell includes a primary cell and at least one secondary cell, and the primary cell and the secondary cell are in the same timing advance group TAG;

[0280] The terminal device determines a default beam, including: the terminal device determines the synchronization signal block SSB of the TA of the measured primary cell as the default beam.

[0281] Optionally, the default beam is used to transmit signals in the primary cell, and the default beam is also used to transmit signals in the secondary cell; the primary cell and the secondary cell are configured in a first set, and the first set is used to configure multiple cells to update beams according to at least one beam indication.

[0282] Optionally, the terminal device obtains the TA of the target cell among the multiple cells indicated by the first set, and the target cell is any cell indicated by the first set; the terminal device determines a third synchronization signal block SSB according to the TA of the target cell, and the third SSB is used to measure the TA of the target cell, and the third SSB is the SSB of the candidate cell; the terminal device determines the third SSB as the default beam for any one or more cells in the first set.

[0283] The present application is described above from the perspective of method, and other embodiments provided by the present application will be further described below.

[0284] See also Figure 6 , is a schematic diagram of an implementation of a communication device provided in the present application, and the communication device 600 includes a processing module 601 and a transceiver module 602. The communication device 600 can implement the functions of the communication device (including terminal equipment and / or network equipment, etc.) in the above method embodiment, and thus can also achieve the beneficial effects of the above method embodiment. In the embodiment of the present application, the communication device 600 can be a terminal device and / or a network device, or an integrated circuit or component inside the terminal device and / or the network device, such as a chip.

[0285] The transceiver module 602 can realize corresponding communication functions, and can also be called a communication interface or a communication unit, for realizing signal transmission and reception or signal input and output. The processing module 601 is used to perform processing operations other than signal transmission and reception.

[0286] Optionally, the communication device 600 may further include a storage module, which may be used to store instructions and / or data, and the processing module 602 may read the instructions and / or data in the storage module, so that the communication device can implement the aforementioned Figure 4-Figure 5 Any of the various method embodiments shown.

[0287] The communication device 600 can be used to perform the actions performed by the communication device (terminal device or network device) in each method embodiment above. The communication device 600 can be a communication device or a component that can be configured in a communication device. The transceiver module 602 is used to perform the transceiver-related operations on the communication device side in the above method embodiment, and the processing module 602 is used to perform the processing-related operations on the communication device side in the above method embodiment.

[0288] Optionally, the transceiver module 602 may include a sending module and a receiving module. The sending module is used to execute the above Figure 4-Figure 5 The sending operation of the communication device in each method embodiment shown in the figure. The receiving module is used to perform the above Figure 4-Figure 5 The receiving operation of the communication device in each method embodiment is shown.

[0289] It should be noted that the communication device 600 may include a sending module but not a receiving module. Alternatively, the communication device 600 may include a receiving module but not a sending module. Specifically, it depends on whether the above solution executed by the communication device 600 includes a sending action and a receiving action.

[0290] See also Figure 7 , is another schematic structural diagram of a communication device 700 provided in the present application, and the communication device 700 at least includes an input and output interface 702. The communication device 700 may be a chip or an integrated circuit.

[0291] Optionally, the communication device further includes a logic circuit 701.

[0292] in, Figure 6 The transceiver module 602 shown may be a communication interface, which may be Figure 7 The input / output interface 702 in the communication interface may include an input interface and an output interface. Alternatively, the communication interface may also be a transceiver circuit, which may include an input interface circuit and an output interface circuit.

[0293] Optionally, when the communication device 700 is a session management function (or a component in a session management function) in the aforementioned embodiment, the input / output interface 702 is used to input / output information; the logic circuit 701 is used to execute the aforementioned Figure 4-Figure 5 And methods executed by terminal devices and / or network devices in related embodiments.

[0294] The logic circuit 701 and the input / output interface 702 may also execute other steps executed by the communication device in any embodiment and achieve corresponding beneficial effects, which will not be described in detail here.

[0295] In one possible implementation, Figure 6 The processing module 601 shown can be Figure 7 The logic circuit 701 in.

[0296] Optionally, the logic circuit 701 may be a processing device, and the functions of the processing device may be partially or completely implemented by software. The functions of the processing device may be partially or completely implemented by software.

[0297] Optionally, the processing device may include a memory and a processor, wherein the memory is used to store a computer program, and the processor reads and executes the computer program stored in the memory to perform corresponding processing and / or steps in any one of the method embodiments.

[0298] Alternatively, the processing device may include only a processor. A memory for storing a computer program is located outside the processing device, and the processor is connected to the memory via a circuit / wire to read and execute the computer program stored in the memory. The memory and the processor may be integrated together, or may be physically independent of each other.

[0299] Optionally, the processing device may be one or more chips, or one or more integrated circuits. For example, the processing device may be one or more field-programmable gate arrays (FPGA), application specific integrated circuits (ASIC), system on chip (SoC), central processor unit (CPU), network processor (NP), digital signal processor (DSP), microcontroller unit (MCU), programmable logic device (PLD) or other integrated chips, or any combination of the above chips or processors.

[0300] See also Figure 8 , is the communication device 800 involved in the above-mentioned embodiments provided by the embodiments of the present application, and the communication device 800 can specifically be the communication device as a terminal device and / or a network device in the above-mentioned embodiments.

[0301] Among them, a possible logical structure diagram of the communication device 800 is shown, and the communication device 800 may include but is not limited to at least one processor 801 and a communication port 802.

[0302] Further optionally, the device may also include at least one of a memory 803 and a bus 804 . In an embodiment of the present application, the at least one processor 801 is used to control and process the actions of the communication device 800 .

[0303] In addition, the processor 801 can be a central processing unit, a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a transistor logic device, a hardware component or any combination thereof. It can implement or execute various exemplary logic blocks, modules and circuits described in conjunction with the disclosure of this application. The processor can also be a combination that implements a computing function, such as a combination of one or more microprocessors, a combination of a digital signal processor and a microprocessor, and the like. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here.

[0304] It should be noted that Figure 8The communication device 800 shown can be specifically used to implement the steps implemented by the terminal device and / or the network device in the aforementioned method embodiment, and achieve the corresponding technical effects of the terminal device and / or the network device. Figure 8 The specific implementation methods of the communication device shown can all refer to the description in the aforementioned method embodiment, and will not be described in detail here.

[0305] See also Fig. 9 , is a schematic diagram of the structure of the communication device 900 involved in the above embodiment provided in the embodiment of the present application. The communication device 900 may be a communication device as a terminal device and / or a network device in the above embodiment. The structure of the communication device may refer to Fig. 9 The structure shown.

[0306] The communication device 900 includes at least one processor 901 and at least one network interface 904. Further optionally, the communication device also includes at least one memory 902, at least one transceiver 903 and one or more antennas 905. The processor 901, the memory 902, the transceiver 903 and the network interface 904 are connected, for example, through a bus. In an embodiment of the present application, the connection may include various interfaces, transmission lines or buses, etc., which are not limited in this embodiment. The antenna 905 is connected to the transceiver 903. The network interface 904 is used to enable the communication device to communicate with other communication devices through a communication link. For example, the network interface 904 may include a network interface between the communication device and the core network device, such as an S1 interface, and the network interface may include a network interface between the communication device and other communication devices (such as other radio access networks or core network devices), such as an X2 or Xn interface.

[0307] The processor 901 is mainly used to process the communication protocol and communication data, and to control the entire communication device, execute the software program, and process the data of the software program, for example, to support the communication device to perform the actions described in the embodiment. The communication device may include a baseband processor and a central processing unit, the baseband processor is mainly used to process the communication protocol and communication data, and the central processing unit is mainly used to control the entire terminal device, execute the software program, and process the data of the software program. Fig. 9The processor 901 in the embodiment can integrate the functions of the baseband processor and the central processor. It can be understood by those skilled in the art that the baseband processor and the central processor can also be independent processors, which are interconnected through technologies such as buses. It can be understood by those skilled in the art that the terminal device can include multiple baseband processors to adapt to different network formats, and the terminal device can include multiple central processors to enhance its processing capabilities. The various components of the terminal device can be connected through various buses. The baseband processor can also be expressed as a baseband processing circuit or a baseband processing chip. The central processor can also be expressed as a central processing circuit or a central processing chip. The function of processing the communication protocol and the communication data can be built into the processor, or it can be stored in the memory in the form of a software program, and the processor executes the software program to realize the baseband processing function.

[0308] The memory is mainly used to store software programs and data. The memory 902 can be independent and connected to the processor 901. Optionally, the memory 902 can be integrated with the processor 901, for example, integrated into a chip. Among them, the memory 902 can store program codes for executing the technical solutions of the embodiments of the present application, and the execution is controlled by the processor 901. The various types of computer program codes executed can also be regarded as drivers of the processor 901.

[0309] Fig. 9 Only one memory and one processor are shown. In an actual terminal device, there may be multiple processors and multiple memories. The memory may also be referred to as a storage medium or a storage device, etc. The memory may be a storage element on the same chip as the processor, i.e., an on-chip storage element, or an independent storage element, which is not limited in the embodiments of the present application.

[0310] The transceiver 903 can be used to support the reception or transmission of radio frequency signals between the communication device and the terminal, and the transceiver 903 can be connected to the antenna 905. The transceiver 903 includes a transmitter Tx and a receiver Rx. Specifically, one or more antennas 905 can receive radio frequency signals, and the receiver Rx of the transceiver 903 is used to receive the radio frequency signal from the antenna, convert the radio frequency signal into a digital baseband signal or a digital intermediate frequency signal, and provide the digital baseband signal or the digital intermediate frequency signal to the processor 901, so that the processor 901 further processes the digital baseband signal or the digital intermediate frequency signal, such as demodulation and decoding. In addition, the transmitter Tx in the transceiver 903 is also used to receive a modulated digital baseband signal or a digital intermediate frequency signal from the processor 901, and convert the modulated digital baseband signal or the digital intermediate frequency signal into a radio frequency signal, and send the radio frequency signal through one or more antennas 905. Specifically, the receiver Rx can selectively perform one or more stages of down-mixing and analog-to-digital conversion processing on the RF signal to obtain a digital baseband signal or a digital intermediate frequency signal, and the order of the down-mixing and analog-to-digital conversion processing is adjustable. The transmitter Tx can selectively perform one or more stages of up-mixing and digital-to-analog conversion processing on the modulated digital baseband signal or digital intermediate frequency signal to obtain a RF signal, and the order of the up-mixing and digital-to-analog conversion processing is adjustable. The digital baseband signal and the digital intermediate frequency signal can be collectively referred to as a digital signal.

[0311] The transceiver 903 may also be referred to as a transceiver module, a transceiver, a transceiver device, etc. Optionally, a device in the transceiver module for implementing a receiving function may be regarded as a receiving unit, and a device in the transceiver module for implementing a sending function may be regarded as a sending unit, that is, the transceiver module includes a receiving unit and a sending unit, the receiving unit may also be referred to as a receiver, an input port, a receiving circuit, etc., and the sending unit may be referred to as a transmitter, a transmitter, or a transmitting circuit, etc.

[0312] In the embodiment of the present application, the antenna and the radio frequency circuit having the transceiver function may be regarded as the transceiver 903 of the terminal device, and the processing unit having the processing function may be regarded as the processor 901 of the terminal device. Fig. 9 As shown, the terminal device includes a transceiver 903 and a processor 901. The transceiver 903 may also be referred to as a transceiver unit, a transceiver, a transceiver device, etc. The processor 901 may also be referred to as a processing unit, a processing board, a processing module, a processing device, etc.

[0313] Optionally, the device used to implement the receiving function in the transceiver 903 may be regarded as a receiving unit, and the device used to implement the sending function in the transceiver 903 may be regarded as a sending unit, that is, the transceiver 903 includes a receiving unit and a sending unit. The transceiver unit may sometimes be referred to as a transceiver, or a transceiver circuit, etc. The receiving unit may sometimes be referred to as a receiver, a receiver, or a receiving circuit, etc. The sending unit may sometimes be referred to as a transmitter, a transmitter, or a transmitting circuit, etc.

[0314] It should be understood that the transceiver 903 is used to perform sending and receiving operations of the communication device (terminal device or network device) in the above-mentioned method embodiments, and the processor 901 is used to perform other operations except sending and receiving operations on the communication device (terminal device or network device) in the above-mentioned method embodiments.

[0315] When the communication device is a chip, the chip includes a transceiver unit and a processing unit, wherein the transceiver unit may be an input / output circuit or a communication interface; and the processing unit may be a processor or a microprocessor or an integrated circuit or a logic circuit integrated on the chip.

[0316] It should be noted that Fig. 9 The communication device 900 shown can be specifically used to implement the steps implemented by the terminal device and / or the network device in the aforementioned method embodiment, and achieve the corresponding technical effects of the terminal device and / or the network device. Fig. 9 The specific implementation methods of the communication device 900 shown can all refer to the description in the aforementioned method embodiment, and will not be repeated here.

[0317] An embodiment of the present application also provides a computer-readable storage medium storing one or more computer-executable instructions. When the computer-executable instructions are executed by a processor, the processor executes the method as a possible implementation method of a terminal device or a network device in the aforementioned embodiment.

[0318] An embodiment of the present application also provides a computer program product (or computer program) storing one or more computers. When the computer program product is executed by the processor, the processor executes the method of the possible implementation mode of the above-mentioned terminal device or network device.

[0319] The embodiment of the present application also provides a chip system, which includes at least one processor for supporting a communication device to implement the functions involved in the possible implementation methods of the above-mentioned communication device. Optionally, the chip system also includes an interface circuit, which provides program instructions and / or data to the at least one processor. In one possible design, the chip system may also include a memory, which is used to store the necessary program instructions and data for the communication device. The chip system can be composed of chips, and may also include chips and other discrete devices, wherein the communication device can specifically be a terminal device or a network device in the aforementioned method embodiment.

[0320] An embodiment of the present application also provides a communication system, which includes the terminal device and / or network device in any of the above embodiments.

[0321] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the unit is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0322] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0323] In addition, each functional unit in each embodiment of the present application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of a software functional unit. If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a wireless access network, etc.) to perform all or part of the steps of the method of each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk and other media that can store program code.

Claims

1. A beam-based communication method, characterized in that: include: The terminal device receives a transmission configuration indicating first indication information, where the first indication information is used to activate a TCI state of a candidate cell, where the TCI state of the activated candidate cell includes a first TCI state, where the first TCI state includes one or more TCI states; The terminal device measures a first synchronization signal block SSB according to the first indication information to obtain a first measurement result, wherein the first SSB has a quasi-co-site QCL relationship with at least one channel state information reference signal CSI-RS, the at least one CSI-RS is a reference signal in the QCL information of the first TCI state, the type of the QCL information of the first TCI state is type A and / or type D, the first SSB is the SSB of the candidate cell, and the at least one CSI-RS is the CSI-RS of the candidate cell.

2. The method according to claim 1, characterized in that The method further comprises: The terminal device receives a handover command, where the handover command instructs the terminal device to handover from the serving cell to the candidate cell, where the handover command is used to indicate a second TCI state, where the second TCI state belongs to the first TCI state; The terminal device measures, according to the first measurement result, a reference signal corresponding to the second TCI state to obtain a second measurement result; The terminal device activates the second TCI state according to the second measurement result.

3. The method according to claim 1 or 2, characterized in that: The terminal device measures the first synchronization signal block SSB according to the first indication information to obtain the first measurement result, including: The terminal device determines the QCL information of the first TCI state according to the first indication information; The terminal device determines, according to the QCL information of the first TCI state, the at least one CSI-RS corresponding to the first TCI state; The terminal device determines, according to the configuration information of the at least one CSI-RS, a third TCI state, wherein the configuration information of the at least one CSI-RS includes identification information of the third TCI state, and the third TCI state is used to determine a reception parameter for receiving a reference signal corresponding to the first TCI state; The terminal device determines the first SSB according to the QCL information of the third TCI state, wherein the QCL information of the third TCI state includes index information of the first SSB; The terminal device measures the first SSB to obtain the first measurement result.

4. The method according to claim 3, characterized in that The quasi co-site QCL types of the third TCI state are type C and type D.

5. The method according to any one of claims 1 to 4, characterized in that The first TCI state also includes a fourth TCI state, and the quasi-co-site QCL type of the fourth TCI state is type C and type D.

6. The method according to claim 5, characterized in that The terminal device measures the first synchronization signal block SSB according to the first indication information to obtain the first measurement result, including: The terminal device determines, according to the first indication information, the QCL information of the fourth TCI state, where the QCL information of the fourth TCI state indicates that the source reference signal of the fourth TCI state includes SSB; The terminal device determines the first SSB according to the QCL information of the fourth TCI state, where the QCL information of the fourth TCI state includes index information of the first SSB; The terminal device measures the first SSB to obtain the first measurement result.

7. The method according to any one of claims 1 to 6, characterized in that Before the terminal device receives the first indication information, the method further includes: The terminal device receives configuration information, where the configuration information includes QCL information of the TCI state of the candidate cell and / or relevant information of the CSI-RS of the candidate cell.

8. The method according to any one of claims 1 to 7, characterized in that Before the terminal device measures, according to the first measurement result, a reference signal corresponding to the second TCI state, and obtains the second measurement result, the method further includes: The terminal device determines, based on the first measurement result, the TCI corresponding to the first SSB as a default beam, and the default beam is used to transmit signals to a switched service cell, and the switched service cell belongs to the candidate cell.

9. The method according to any one of claims 1 to 8, characterized in that The TCI corresponding to the reference signal in the first TCI state is not allowed to be indicated by the switching command, or the TCI corresponding to the reference signal in the first TCI state is not allowed to be used for data transmission after receiving the switching command.

10. A beam-based communication method, characterized in that: include: The terminal device receives a handover command, wherein the handover command instructs the terminal device to handover from a serving cell to a candidate cell; When any one or more of the first conditions are met, the terminal device determines a default beam, where the default beam is used to transmit signals with a switched serving cell, where the switched serving cell belongs to the candidate cell; The first condition includes: the transmission configuration indication TCI is not indicated in the handover command, and the terminal device determines the TA according to the measurement result of the downlink reference signal; Alternatively, the timing advance TA is not indicated in the switching command, and the terminal device determines the TA according to the measurement result of the downlink reference signal; Alternatively, the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is the same as the TA of the serving cell, Alternatively, the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is 0; Alternatively, the TCI indicated in the handover command is not activated in advance; Alternatively, the source reference signal of the TCI indicated in the switching command includes a channel state information reference signal CSI-RS, and the terminal device does not measure the CSI-RS before receiving the switching command; Alternatively, the switching command indicates TCI, and the terminal device feeds back a hybrid automatic repeat request response HARQ-ACK according to the switching command, and the time of feeding back the HARQ-ACK does not reach the beam effective time point.

11. The method according to claim 10, characterized in that When one or more of the following of the first condition is met, the terminal device determines the default beam, including: The first condition includes: the handover command does not indicate a transmission configuration indication TCI, and the terminal device determines the TA according to a measurement result of a downlink reference signal; or the handover command does not indicate a timing advance TA, and the terminal device determines the TA according to a measurement result of a downlink reference signal; The terminal device determines the default beam, including: the terminal device determines a second synchronization signal block SSB as the default beam, the second SSB is the SSB of the candidate cell, the second SSB is used to measure the TA of the candidate cell, or the second SSB has a quasi-co-site QCL relationship with a reference signal for measuring the TA of the candidate cell.

12. The method according to claim 11, characterized in that When one or more of the following of the first condition is met, the terminal device determines the default beam, including: The first condition includes: the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is the same as the TA of the serving cell; or the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is 0; The terminal device determines the default beam, including: The terminal device determines, according to the switching command, a fifth TCI state indicated by the switching command; The terminal device determines a first reference signal as the default beam, or the terminal device determines a synchronization signal block SSB associated with the first reference signal as the default beam, and the first reference signal is a reference signal indicated by the quasi-co-site QCL information of the fifth TCI state.

13. The method according to claim 12, characterized in that The type of the QCL information of the third TCI state is type D; The first reference signal is a channel state information reference signal CSI-RS.

14. The method according to claim 11, characterized in that When one or more of the following of the first condition is met, the terminal device determines the default beam, including: The first condition includes: the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is the same as the TA of the serving cell; or the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is 0; The terminal device determines the default beam, including: The terminal device determines, from the synchronization signal blocks SSB of the candidate cells reported by the terminal device to the network device, an SSB with the largest reference signal received power; The terminal device determines the SSB with the largest reference signal receiving power as the default beam.

15. The method according to claim 11, characterized in that The first condition further includes: the serving cell includes a primary cell and at least one secondary cell, or the candidate cell includes a primary cell and at least one secondary cell, and the primary cell and the secondary cell are in the same timing advance group TAG; The terminal device determines the default beam, including: The terminal device determines to measure the synchronization signal block SSB of the TA of the primary cell as the default beam.

16. The method according to claim 15, characterized in that The default beam is used for transmitting signals in the primary cell, and the default beam is also used for transmitting signals in the secondary cell; The primary cell and the secondary cell are configured in a first set, and the first set is used to configure multiple cells to update beams according to at least one beam indication.

17. A communication device, characterized in that: include: A transceiver module, configured to receive first indication information indicating a transmission configuration, where the first indication information is used to activate a TCI state of a candidate cell, where the TCI state of the activated candidate cell includes a first TCI state, where the first TCI state includes one or more TCI states; A processing module is used to measure a first synchronization signal block SSB according to the first indication information to obtain a first measurement result, wherein the first SSB has a quasi-co-site QCL relationship with at least one channel state information reference signal CSI-RS, the at least one CSI-RS is a reference signal in the QCL information of the first TCI state, the type of the QCL information of the first TCI state is type A and / or type D, the first SSB is the SSB of the candidate cell, and the at least one CSI-RS is the CSI-RS of the candidate cell.

18. A communication device, characterized in that: include: A transceiver module, used for a terminal device to receive a handover command, wherein the handover command instructs the terminal device to handover from a serving cell to a candidate cell; a processing module, configured to determine a default beam when any one or more of the first conditions are met, wherein the default beam is used to transmit a signal with a serving cell after switching, and the serving cell after switching belongs to the candidate cell; The first condition includes: the transmission configuration indication TCI is not indicated in the handover command, and the terminal device determines the TA according to the measurement result of the downlink reference signal; Alternatively, the timing advance TA is not indicated in the switching command, and the terminal device determines the TA according to the measurement result of the downlink reference signal; Alternatively, the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is the same as the TA of the serving cell, Alternatively, the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is 0; Alternatively, the TCI indicated in the handover command is not activated in advance; Alternatively, the source reference signal of the TCI indicated in the switching command includes a channel state information reference signal CSI-RS, and the terminal device does not measure the CSI-RS before receiving the switching command; Alternatively, the switching command indicates TCI, and the terminal device feeds back a hybrid automatic repeat request response HARQ-ACK according to the switching command, and the time of feeding back the HARQ-ACK does not reach the beam effective time point.

19. A communication device, characterized in that: Including communication interface and processor: The communication interface is used to input and / or output signaling or data; The processor is used to execute a computer executable program so that the method described in any one of claims 1 to 9 is executed, or the method described in any one of claims 10 to 16 is executed.

20. A communication device, characterized in that: including a processor and memory, The memory is used to store computer programs or instructions; The processor is used to execute the computer program or instructions in the memory, so that the method described in any one of claims 1 to 9 is executed, or the method described in any one of claims 10 to 16 is executed.

21. A computer-readable storage medium comprising instructions, characterized in that: When the instructions are executed by a processor, the method of any one of claims 1-9 or claims 10-16 is implemented.

22. A chip system, characterized in that: The chip system includes at least one processor, and when the program instructions are executed in the at least one processor, the method described in any one of claims 1 to 9 or claims 10 to 16 is implemented.

23. A communication system, characterized in that: The invention comprises a communication device for executing the method according to any one of claims 1 to 9, and / or a communication device for executing the method according to any one of claims 10 to 16.

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