Beam-based communication method and related apparatus

Abstract

Embodiments of the present application provide a beam-based communication method and a related apparatus. The method comprises: a terminal device receives first indication information of a transmission configuration indicator (TCI), 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, and the first TCI state comprising one or more TCI states; and on the basis of the first indication information, the terminal device measures a first synchronization signal block (SSB) to obtain a first measurement result, the first SSB having a quasi-co-location (QCL) relationship with at least one channel state information reference signal (CSI-RS), the at least one CSI-RS being a reference signal in QCL information of the first TCI state, the type of the QCL information of the first TCI state being type A and / or type D, the first SSB being an SSB of the candidate cell, and the at least one CSI-RS being a CSI-RS of the candidate cell. An SSB associated with a TCI state is pre-measured by means of the first indication information, so as to quickly activate the TCI state. The communication interruption time of terminal devices is shortened, and the communication quality of terminal devices is improved.

Description

A beam-based communication method and related device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office on August 11, 2024, with application number 202311019046.3 and application name “A Beam-Based Communication Method and Related Devices”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a beam-based communication method and related devices. Background Art

[0003] 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. To overcome this problem, high-frequency communication uses analog beam technology, which is processed through a large-scale antenna array to concentrate the signal energy in a smaller range, forming a signal similar to a light beam, called an analog beam (abbreviated 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.

[0004] During the process of switching from a serving cell to a 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 measurement phase of the terminal device is entered, which is as follows: First, the terminal device tracks and measures the above-determined synchronization signal-broadcast channel resource block (Synchronization Signal and PBCH Block, 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. 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.

[0005] 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 based on the measurement results. The above process has a large time delay, which causes the terminal device to suspend communication for a long time, reducing the communication quality.

[0006] Summary of the Invention

[0007] In a first aspect, an embodiment of the present application proposes a beam-based communication method, including:

[0008] The terminal device receives 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, and the first TCI state includes one or more TCI states;

[0009] The terminal device measures the first synchronization signal block SSB according to the first indication information to obtain a first measurement result, where the first SSB has a quasi-co-site QCL relationship with at least one channel state information reference signal CSI-RS, and the at least one CSI-RS is a reference signal in the QCL information of the first TCI state, and 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.

[0010] 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.

[0011] In an embodiment of the present application, when a terminal device switches from a serving cell to a candidate cell, the terminal device may determine a first TCI state to be activated based on received first indication information. A first synchronization signal block (SSB) is then determined based on the first TCI state, and the first SSB is pre-measured to obtain a first measurement result. By pre-measuring the SSB associated with the TCI state using the first indication information, the TCI state can be quickly activated. This reduces the communication interruption time of the terminal device and improves the communication quality of the terminal device.

[0012] 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.

[0013] In this embodiment of the present application, after receiving a handover command, a terminal device measures a 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 for data transmission. This reduces the communication interruption time of the terminal device and improves the communication quality of the terminal device.

[0014] 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.

[0015] 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 reception parameters of the reference signal corresponding to the first TCI state. The reception 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.

[0016] 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, and thus the first SSB can be determined based on the third TCI state.

[0017] In conjunction 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 can include TCI states of multiple QCL types, thereby improving the implementation flexibility of the solution.

[0018] 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 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.

[0019] 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 further includes: the terminal device receives configuration information, and the configuration information includes the QCL information of the TCI state of the candidate cell and / or the relevant information of the CSI-RS of the candidate cell. The configuration information is the configuration information related to the TCI state of the candidate cell, for example, the configuration information includes: the quasi-co-site QCL information of the TCI state of the candidate cell and / or the 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.

[0020] 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 based on the first measurement result, and before obtaining 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 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.

[0021] 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.

[0022] In a second aspect, an embodiment of the present application proposes a beam-based communication method, including:

[0023] The terminal device receives 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, and the first TCI state includes one or more TCI states;

[0024] The terminal device measures the first synchronization signal block SSB according to the first indication information to obtain a first measurement result, where the first SSB has a quasi-co-site QCL relationship with at least one channel state information reference signal CSI-RS, and the at least one CSI-RS is a reference signal in the QCL information of the first TCI state, and 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.

[0025] 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.

[0026] In an embodiment of the present application, when a terminal device switches from a serving cell to a candidate cell, the terminal device may determine a first TCI state to be activated based on received first indication information. A first synchronization signal block (SSB) is then determined based on the first TCI state, and the first SSB is pre-measured to obtain a first measurement result. By pre-measuring the SSB associated with the TCI state using the first indication information, the TCI state can be quickly activated. This reduces the communication interruption time of the terminal device and improves the communication quality of the terminal device.

[0027] 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.

[0028] In this embodiment of the present application, after receiving a handover command, a terminal device measures a 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 for data transmission. This reduces the communication interruption time of the terminal device and improves the communication quality of the terminal device.

[0029] In combination with the second aspect, in an optional implementation 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.

[0030] 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 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.

[0031] 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 further includes: the terminal device receives configuration information, and the configuration information includes the QCL information of the TCI state of the candidate cell and / or the relevant information of the CSI-RS of the candidate cell. The configuration information is the configuration information related to the TCI state of the candidate cell, for example, the configuration information includes: the quasi-co-site QCL information of the TCI state of the candidate cell and / or the 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.

[0032] 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 based on the first measurement result, and before obtaining 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 the default beam, 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.

[0033] 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, it is possible to avoid affecting the normal communication of the terminal device and improve the communication quality of the terminal device.

[0034] In a third aspect, an embodiment of the present application proposes a beam-based communication method, including:

[0035] 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;

[0036] 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;

[0037] The first condition includes: no transmission configuration indication TCI is indicated in the handover command, and the terminal device determines the TA according to the measurement result of the downlink reference signal;

[0038] Alternatively, the timing advance TA is not indicated in the handover command, and the terminal device determines the TA according to a measurement result of a downlink reference signal;

[0039] 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,

[0040] Alternatively, the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is 0;

[0041] Alternatively, the TCI indicated in the handover command is not activated in advance;

[0042] Alternatively, the source reference signal of the TCI indicated in the handover command includes a channel state information reference signal CSI-RS, and the terminal device does not measure the CSI-RS before receiving the handover command;

[0043] 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 when the HARQ-ACK is fed back does not reach the beam effective time point.

[0044] Specifically, the terminal device determines the TA based on downlink reference signal measurement results, including: before the terminal device switches from the serving cell to the candidate cell, the network equipment of the serving cell configures the terminal device. 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. Based on this configuration information, the terminal device calculates the timing advance based on the time difference between the two SSB arrival times.

[0045] In an embodiment of the present application, when a terminal device does not have a valid beam indicated by a handover command and cannot determine a default beam through a random access channel (RACH) beam, the terminal device may determine a default beam through the above method. The default beam is used to transmit signals to the serving cell after the handover. This reduces the communication interruption time of the terminal device and improves the communication quality of the terminal device.

[0046] 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 are met, the terminal device determines the default beam, including: the first condition, including: 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, when a specific first condition is met, the terminal device can determine the second SSB as the default beam, thereby improving the implementation flexibility of the solution.

[0047] In conjunction 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 most recently reported by the terminal device to the network device. Through the above method, the communication quality of the terminal device is improved.

[0048] 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 for the last time, 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 periodically measures the SSB of the candidate cell, and then reports 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.

[0049] 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 are 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, when a specific first condition is met, 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.

[0050] 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.

[0051] 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 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, when a specific first condition is met, 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.

[0052] In combination with the third aspect, in an optional implementation of the third aspect, the first condition also 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. 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 where the terminal device configures carrier aggregation in the serving cell and the serving 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.

[0053] 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.

[0054] 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 cell indicated by the first set; the terminal device determines a third synchronization signal block SSB based on 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 of any one or more cells in the first set.

[0055] In a fourth aspect, an embodiment of the present application provides a communication device, including:

[0056] 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 activated TCI state of the candidate cell includes a first TCI state, and the first TCI state includes one or more TCI states;

[0057] 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, where the first SSB has a quasi-co-site QCL relationship with at least one channel state information reference signal CSI-RS, and the at least one CSI-RS is a reference signal in the QCL information of the first TCI state, and 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.

[0058] In some optional embodiments of the present application, the transceiver module is further configured to receive a handover command, the handover command instructing the terminal device to handover from the serving cell to the candidate cell, the handover command being used to indicate a second TCI state, where the second TCI state belongs to the first TCI state;

[0059] The processing module is further configured to measure a reference signal corresponding to the second TCI state based on the first measurement result to obtain a second measurement result;

[0060] The processing module is further configured to activate the second TCI state according to the second measurement result.

[0061] In some optional implementations of the present application, the processing module is further configured to determine QCL information of the first TCI state according to the first indication information;

[0062] The processing module is further configured to determine, based on the QCL information of the first TCI state, the at least one CSI-RS corresponding to the first TCI state;

[0063] The processing module is further configured to determine a third TCI state based on 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 reception parameter for receiving a reference signal corresponding to the first TCI state;

[0064] 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;

[0065] The processing module is further used to measure the first SSB and obtain the first measurement result.

[0066] In some optional embodiments of the present application, the quasi-co-located QCL type of the third TCI state is type C and / or type D.

[0067] In some optional embodiments of the present application, the first TCI state further includes a fourth TCI state, and the quasi-co-site QCL type of the fourth TCI state is type C and / or type D.

[0068] In some optional embodiments of the present application, the processing module is further configured to determine the QCL information of the fourth TCI state according to the first indication information, where the QCL information of the fourth TCI state indicates that the source reference signal of the fourth TCI state includes an SSB;

[0069] The processing module is further configured 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 index information of the first SSB;

[0070] The processing module is further used to measure the first SSB and obtain the first measurement result.

[0071] In some optional embodiments 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.

[0072] 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.

[0073] In some optional implementations 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.

[0074] In a fifth aspect, an embodiment of the present application provides a communication device, characterized by including:

[0075] 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 activated TCI state of the candidate cell includes a first TCI state, and the first TCI state includes one or more TCI states;

[0076] 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, where the first SSB has a quasi-co-site QCL relationship with at least one channel state information reference signal CSI-RS, and the at least one CSI-RS is a reference signal in the QCL information of the first TCI state, and 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.

[0077] In some optional embodiments of the present application, the transceiver module is further configured to receive a handover command, the handover command instructing the terminal device to handover from the serving cell to the candidate cell, the handover command being used to indicate a second TCI state, where the second TCI state belongs to the first TCI state;

[0078] The processing module is further configured to measure a reference signal corresponding to the second TCI state based on the first measurement result to obtain a second measurement result;

[0079] The processing module is further configured to activate the second TCI state according to the second measurement result.

[0080] In some optional embodiments of the present application, the first TCI state further includes a fourth TCI state, and the quasi-co-site QCL type of the fourth TCI state is type C and / or type D.

[0081] In some optional embodiments of the present application, the processing module is further configured to determine the QCL information of the fourth TCI state according to the first indication information, where the QCL information of the fourth TCI state indicates that the source reference signal of the fourth TCI state includes an SSB;

[0082] The processing module is further configured 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 index information of the first SSB;

[0083] The processing module is further used to measure the first SSB and obtain the first measurement result.

[0084] In some optional embodiments 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.

[0085] 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.

[0086] In some optional implementations 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.

[0087] In a sixth aspect, an embodiment of the present application provides a communication device, characterized by including:

[0088] A transceiver module, configured 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;

[0089] a processing module, configured to determine a default beam when any one or more of the first conditions are met, where the default beam is used to transmit signals with a serving cell after switching, where the serving cell after switching belongs to the candidate cell;

[0090] The first condition includes: no transmission configuration indication TCI is indicated in the handover command, and the terminal device determines the TA according to the measurement result of the downlink reference signal;

[0091] Alternatively, the timing advance TA is not indicated in the handover command, and the terminal device determines the TA according to a measurement result of a downlink reference signal;

[0092] 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,

[0093] Alternatively, the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is 0;

[0094] Alternatively, the TCI indicated in the handover command is not activated in advance;

[0095] Alternatively, the source reference signal of the TCI indicated in the handover command includes a channel state information reference signal CSI-RS, and the terminal device does not measure the CSI-RS before receiving the handover command;

[0096] 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 when the HARQ-ACK is fed back does not reach the beam effective time point.

[0097] 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:

[0098] 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;

[0099] 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 the reference signal for measuring the TA of the candidate cell.

[0100] 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:

[0101] 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;

[0102] The processing module, configured to determine the default beam, includes:

[0103] The processing module is further configured to determine, according to the handover command, a fifth TCI state indicated by the handover command;

[0104] 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.

[0105] In some optional embodiments of the present application, the type of the QCL information of the third TCI state is type D;

[0106] The first reference signal is a channel state information reference signal CSI-RS.

[0107] 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, cause the terminal device to determine the default beam, including:

[0108] 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;

[0109] The processing module is further configured to determine the default beam, including:

[0110] The processing module is further configured to determine an SSB with the largest reference signal received power from the synchronization signal blocks SSB of the candidate cells reported by the terminal device to the network device;

[0111] The processing module is further used to determine the SSB with the largest reference signal receiving power as the default beam.

[0112] 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;

[0113] The processing module is further configured to determine the default beam, including:

[0114] 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.

[0115] In some optional implementations of the present application, 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;

[0116] 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.

[0117] In the seventh aspect of the present application, a communication device is provided, which includes: a processor, a memory, an input and 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.

[0118] In a possible implementation of the seventh aspect, the processor, memory, and input and output devices are respectively connected to the bus.

[0119] 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 enabled to execute any one of the implementation methods of the first aspect, the second aspect or the third aspect.

[0120] The 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 one of the implementation methods of the first, second or third aspects.

[0121] In the tenth aspect, the present application provides a chip system, which includes a processor for executing a computer program or instruction stored in a memory, so that the processor executes the implementation method of any one of the above-mentioned first aspect, second aspect or third aspect.

[0122] In one possible design of the tenth aspect, the chip system further includes a memory for storing computer programs or instructions necessary for the computer device. The processor is configured to retrieve and execute the computer programs or instructions from the memory. The chip system may be composed of a chip alone or may include a chip and other discrete components.

[0123] In a possible design of the tenth aspect, the chip system also includes an input port and an output port, which are used to perform 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 above, wherein the receiving function corresponds to the input port and the sending function corresponds to the output port.

[0124] In an eleventh aspect, the present application provides a communication system, 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

[0125] FIG1 is a schematic diagram of an application scenario proposed in an embodiment of the present application;

[0126] FIG2 is a schematic diagram of a scenario in which a terminal device switches from a serving cell to a candidate cell;

[0127] FIG3 is a schematic diagram of a process of handing over a terminal device from a serving cell to a candidate cell;

[0128] FIG4 is a schematic diagram of an embodiment of a beam-based communication method proposed in an embodiment of the present application;

[0129] FIG5 is a schematic flow chart of another embodiment of a beam-based communication method in an embodiment of the present application;

[0130] FIG6 is a schematic diagram of a communication device provided in an embodiment of the present application;

[0131] FIG7 is another schematic diagram of a communication device provided in an embodiment of the present application;

[0132] FIG8 is another schematic diagram of a communication device provided in an embodiment of the present application;

[0133] FIG9 is another schematic diagram of a communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0134] The terms "first", "second", etc. in the specification and claims of this 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 when describing objects with the same properties in 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 apparatus that includes a series of units is not necessarily limited to those units, but may include other units not expressly listed or inherent to these processes, methods, products or apparatuses.

[0135] 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 merely 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" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0136] 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), world-wide 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 radio access network (open RAN, O-RAN or ORAN), cloud radio access network (CRAN), or wireless fidelity (WiFi) system. The technical solutions of the embodiments of the present application can also be applied to communication systems that integrate two or more of the above systems.

[0137] The part operated by the operator in various communication systems can be called an operator network. The operator network can also be called a PLMN network. It 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 in which mobile network operators (MNOs) 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 (3GPP) standards, referred to as a 3GPP network. Usually, 3GPP networks are operated by operators, including but not limited to fifth-generation mobile communication (5th-generation, 5G) networks (referred to as 5G networks), fourth-generation mobile communication (4th-generation, 4G) networks (referred to as 4G networks) or third-generation mobile communication technology (3rd-generation, 3G) networks (referred to as 3G networks). It also includes future 6G networks. For the convenience of description, the embodiment of the present application will take the operator network (such as a mobile network operator (mobile network operator, MNO) network) as an example for explanation.

[0138] To facilitate understanding of the embodiments of the present application, some application scenarios of this solution are introduced. Please refer to Figure 1, which is a schematic diagram of an application scenario proposed in the embodiments of the present application. In one optional implementation, the transmitting end involved in the embodiments of the present application can be a network device, and the receiving end can be a terminal device. In another optional implementation, the transmitting end involved in the embodiments of the present application can be a terminal device, and the receiving end can be a network device.

[0139] 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 device, 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 capabilities, 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, autonomous driving, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc.The terminal may be a mobile phone, tablet computer, computer with wireless transceiver function, wearable device, vehicle, drone, helicopter, airplane, ship, robot, robotic arm, smart home device, etc. The embodiments of the present application do not limit the device form of the terminal device.

[0140] The network device can be considered a sub-network of the operator network and is the implementation system between the service nodes and terminal devices 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 embodiments 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.

[0141] A RAN node can be a base station, an evolved NodeB (eNodeB), an access point (AP), a transmission reception point (TRP), a next-generation NodeB (gNB), a next-generation base station in a sixth-generation (6G) mobile communication system, a base station in a future mobile communication system, or an access node in a WiFi system. A RAN node can be a macro base station, a micro base station, or an indoor station), a relay node or a donor node, or a wireless controller in a CRAN scenario. Optionally, a RAN node can also be a server, a wearable device, a vehicle, or an onboard device. For example, the access network device in vehicle to everything (V2X) technology can be a road side unit (RSU).

[0142] 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 they can be included in the same network element, such as a baseband unit (BBU). The RU can be included in a radio frequency device or radio frequency unit, such as a remote radio unit (RRU), an active antenna unit (AAU), or a remote radio head (RRH).

[0143] 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, this application uses CU, CU-CP, CU-UP, DU and RU as examples for description. Any unit of CU (or CU-CP, CU-UP), DU and RU in this application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0144] The 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 systems, LTE and 5G hybrid architectures, 5G new radio (NR) systems, and new communication systems emerging in future communication developments. 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.

[0145] In addition, the embodiments of the present application may also be applicable to other future-oriented communication technologies, such as 6G. 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. Those skilled in the art will appreciate that with the evolution of network architecture and the emergence of new service scenarios, the technical solutions provided in this application are also applicable to similar technical problems.

[0146] Below, some technical concepts involved in the embodiments of this application are introduced.

[0147] 1. Beam: A beam is a communication resource. It can be wide, narrow, or any other type of beam. Beam formation can be achieved through beamforming or other techniques. Beamforming techniques include digital beamforming, analog beamforming, and hybrid digital / analog beamforming. Different beams can be considered different resources.

[0148] In the NR protocol, beam can be called spatial domain filter, spatial filter, spatial domain parameter, spatial parameter, spatial parameter, spatial domain setting, spatial setting, quasi-colocation (QCL) information, QCL assumption, or QCL indication, etc. The beam can be indicated by the TCI-state parameter or by the spatial relation parameter. Therefore, in this application, beam can be replaced by spatial filter, spatial filter, spatial parameter, spatial parameter, spatial setting, spatial setting, QCL information, QCL assumption, QCL indication, TCI-state (including uplink TCI-state, downlink TCI-state), or spatial relationship, etc. The above terms are also equivalent to each other. Beam can also be replaced by other terms representing beams, which are not limited in this application.

[0149] 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 sounding signals, etc. The uplink transmit beam can be indicated by any one of the spatial relationship, TCI-state, and sounding reference signal (SRS) resources (indicating the transmit beam using the SRS). Therefore, the uplink transmit beam can also be replaced by an SRS resource.

[0150] 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.

[0151] 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.

[0152] For example, a transmit beam can refer to the distribution of signal strength in different directions in space after a signal is transmitted by an antenna, while a receive beam can refer to the distribution of signal strength in different directions in space after a wireless signal is received by an antenna. It is understood that the one or more antenna ports that form a beam can also be considered an antenna port set.

[0153] When using low- or medium-frequency bands, the transmitter can send signals omnidirectionally or across a wide angle. When using high-frequency bands, thanks to the shorter carrier wavelength of high-frequency communication systems, antenna arrays consisting of multiple antenna elements can be deployed at both the transmitter and receiver ends. The transmitter transmits signals with specific beamforming weights, forming a spatially directional beam. Simultaneously, the receiver receives the signals using an antenna array with specific beamforming weights. This helps improve the received signal power at the receiver and combats path loss.

[0154] 2. Quasi-co-location (QCL): A quasi-co-location relationship is used to indicate that multiple resources have one or more identical or similar communication characteristics. For multiple resources with a quasi-co-location relationship, the same or similar communication configuration can be used. 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, reception parameters, terminal device receive beam number, transmit / receive channel correlation, receive angle of arrival, spatial correlation of receiver antennas, main angle of arrival (AoA), average angle of arrival, spread of AoA, 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 transmitted by at least two groups of antenna ports come from the same transmission point, or the co-location indication is used to indicate whether the channel state information reference signals transmitted by at least two groups of antenna ports come from the same beam group.

[0155] 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 the random access channel (PRACH), the physical uplink control channel (PUCCH), and the physical uplink shared channel (PUSCH). Uplink signals include the channel sounding signal (SRS), the uplink control channel demodulation reference signal (PUCCH-DMRS), the uplink data channel demodulation reference signal (PUSCH-DMRS), the uplink phase noise tracking reference signal (PTRS), and the uplink positioning RS. 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 signals (TRS), LTE / NR positioning signal (positioning RS), etc.

[0156] Regarding TRS, it can be considered that TRS is a CSI-RS resource set (resource set), and TRS is a CSI-RS resource set including one or more CSI-RS resources.

[0157] 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 a quasi-co-location relationship between one or two downlink reference signals and the demodulation reference signal (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, TCI state indication beam is commonly used.

[0158] The TCI is configured for the terminal device by the network device through an RRC message and is referred to as the TCI state in the configuration signaling. After the network device configures the TCI state for the terminal device through the RRC message, the network device can send a media access control layer control element (MAC CE) to the terminal device. The MAC is used to activate one or more TCI states configured by the network device for the terminal device. Optionally, the network device can further send a DCI to the terminal device. The DCI is used to indicate a TCI state among the TCI states activated by the MAC CE.

[0159] The TCI state includes one or two QCL relationships. A QCL relationship characterizes the consistency between the currently received signal / channel and a previously known reference signal. If a QCL relationship exists, the terminal device can inherit the receive or transmit parameters of the previously received reference signal to receive or transmit the incoming signal / channel. Each TCI state corresponds to a beam, and the terminal device can communicate using that beam.

[0160] The following describes the configuration, activation and indication of TCI status.

[0161] TCI state configuration: The network device configures multiple TCI states to the terminal device through Radio Resource Control (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 and are not further explained here.

[0162] TCI State Activation: After a network device is configured with multiple TCI states, it must activate up to eight of them through MAC-CE. For example, these eight TCI states correspond one-to-one to the eight values ​​of the TCI field in the DCI. Specifically, the eight TCI states corresponding to the eight values ​​of the DCI TCI field are determined through the Media Access Control Layer (MAC CE).

[0163] 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 this 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 adopt the corresponding beam to send or receive data.

[0164] It should be noted that the two descriptions of TCI-state and TCI state in this article can be used interchangeably.

[0165] The QCL types related to 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. QCL Type A is used to obtain channel estimation information.

[0166] QCL type B (QCL-TypeB, or type B, or type B), the characteristics of QCL type B include Doppler shift and Doppler spread, etc. QCL type B is used to obtain channel estimation information;

[0167] QCL Type C (QCL-Type C, or Type C, or type C). QCL Type C features include average delay and delay spread. QCL Type C is used to obtain measurement information such as reference signal received power (RSRP);

[0168] 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.

[0169] 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-State information 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 can 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}".

[0170] Regarding the reference signal configuration information in the QCL information, the following uses the TRS configuration information as an example to illustrate. TRS is a special CSI-RS resource set, and TRS configuration information can also be understood as the configuration information of the CSI-RS resource set, such as the "NZP-CSI-RS-ResourceSet information element." The "NZP-CSI-RS-ResourceSet" includes TRS information (trs-info), which is configured as "true."

[0171] The configuration information of TRS may include configuration information of multiple CSI-RS resources (also referred to as CSI-RS configuration information), such as "NZP-CSI-RS-Resource information element". In the configuration information of CSI-RS, the index information of the TCI state (or the identifier of the TCI state) "TCI-StateId" may also be included. 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.

[0172] 5. Common beam: Currently, each channel uses a separate beam indicator. Each channel has its own corresponding beam. In this application, a common beam is defined to be used for multiple channels in the uplink and / or downlink at the same time.

[0173] Common beam: One or more channels, one or more channels, one or more reference signals, and / or one or more reference signals share the same beam. Channels include, but are not limited to, at least one of the following: PDCCH, PDSCH, PUCCH, PUSCH, and PRACH. Reference signals include, but are not limited to, at least one of the following: synchronization signal block (SSB or SS / PBCH), CSI-RS, DMRS, PTRS, TRS, SRS, etc. The CSI-RS can be a CSI-RS configured for beam management or a CSI-RS configured for channel state information acquisition (CSI).

[0174] Joint common beam: A beam used for both uplink and downlink transmission of at least one channel or reference signal. Examples include PDCCH, PDSCH, PUCCH, and PUSCH. A joint common beam is also referred to as an uplink and downlink common beam.

[0175] Uplink common beam: used for simultaneous transmission of multiple uplink channels and / or multiple uplink channels and / or one or more uplink reference signals, for example, PUCCH, PUSCH, and SRS.

[0176] Downlink common beam: used for simultaneous transmission of multiple downlink channels and / or multiple downlink channels and / or one or more downlink reference signals, such as PDCCH, PDSCH, and CSI-RS.

[0177] Public beam form: The public beam can be a newly defined structure (different from the existing TCI-state). For example, the public beam includes relevant information of the beam indication, including but not limited to one or more of the following: public beam 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)), and path loss reference signal identifier.

[0178] Application scope of common beams: Common beams can be cell-level, meaning a common beam is used for transmission across multiple channels within a cell. Common beams can also be bandwidth part (BWP)-level, meaning they are used for transmission across multiple beams within a BWP. Common beams can also be cross-cell, meaning they are used for transmission across multiple channels across multiple cells. These multiple cells can be within a frequency band or across multiple frequency bands.

[0179] Exemplarily, the common beam may also be referred to as a unified transmission configuration indicator (UTCI).

[0180] Please refer to Figure 2, which is 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 the switching of a terminal device 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 area), 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 cell edge, as the signal quality of the serving cell deteriorates, it is necessary to switch from the serving cell to the candidate cell, that is, to switch from the communication service provided by the serving cell to the communication service provided by the candidate cell. It should be noted that each cell can be configured with multiple carrier components (CCs), and the carrier may also be referred to as a serving cell.

[0181] Taking Figure 2 as an example, the following describes the specific process of a terminal device switching from a serving cell to a candidate cell. Please refer to Figure 3, which is a schematic diagram of a process of a terminal device switching from a serving cell to a candidate cell. Specifically, it includes:

[0182] A1. The terminal device obtains configuration information. This configuration information includes configuration information of the TCI state and configuration information of related reference signals. This configuration information comes from a first network device, which is a network device in the serving cell. Because the terminal device may be configured with multiple candidate cell configurations, before determining the target candidate cell to which the terminal device will switch, the terminal device will incur a huge computational burden in parsing the configurations of all candidate cells. 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 handover command in step A2.

[0183] The configuration information may be carried in an RRC message.

[0184] A2. The first network device sends a handover command to the terminal device. The handover command indicates a TCI state, and the terminal device determines a common beam to be switched based on the TCI state indicated by the handover command. The handover command may be carried in a MAC CE message.

[0185] 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. The terminal device then 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 based on 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. The TCI is different from the TCI indicated in the switching command. The TCI state of the received TRS includes the SSB index.

[0186] A4. The terminal device tracks and measures the SSB. After determining the TRS configuration information, the terminal device needs to track and measure the TRS. Before measuring the TRS, the terminal device must first track and measure the SSB corresponding to the TRS to determine the beam. Based on the SSB measurement results, the corresponding TRS is measured. Therefore, the terminal device must first measure the SSB.

[0187] A5. After the terminal device obtains the SSB measurement result, the terminal device tracks and measures the TRS based on the SSB measurement result.

[0188] A6. The terminal device activates the TCI indicated by the handover command based on the measurement result of the TRS.

[0189] A7. The terminal device and the second network device use the activated TCI as a common beam to transmit signals, and the second network device is a network device of the candidate cell.

[0190] Through the above process, the terminal device activates the TCI state, which is used to transmit signals with the candidate cell, enabling the terminal device to switch from the serving cell to the candidate cell. The applicant's research has found that the terminal device can only parse the configuration information related to the candidate cell after receiving the handover command, then measure the SSB and TRS corresponding to the candidate cell's TCI state, and finally activate the TCI state based on the measurement results. This process is subject to significant latency, resulting in long communication pauses for the terminal device and reduced communication quality.

[0191] 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.

[0192] The following describes an embodiment of the present application with reference to the accompanying drawings. Please refer to Figure 4, which is a flow chart of an embodiment of a beam-based communication method proposed in an embodiment of the present application. The beam-based communication method proposed in an embodiment of the present application includes:

[0193] S1. Obtain configuration information.

[0194] 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.

[0195] Regarding candidate cells, candidate cells refer to candidates for handover target cells, and candidate cells may include multiple cells. Candidate cells may be cells geographically adjacent to the current serving cell, or other cells, which are not limited in the present embodiment.

[0196] After receiving the configuration information, the terminal device may parse the configuration information in advance. For example, the terminal device may parse 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.

[0197] 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.

[0198] The above configuration information is referred to as first configuration information, and other configuration information of the candidate cell is referred to as second configuration information. 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, or parsed and applied, only after the terminal device receives a handover command to switch to the candidate cell.

[0199] In one 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 the first information element and the 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.

[0200] 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.

[0201] It should be noted that the execution steps of the network device in the embodiment of the present application can be executed by the base station, or by any one or more network elements in O-CU-CP, O-CU-UP, O-DU, or O-RU. The embodiment of the present application is not limited to this.

[0202] S2. The first network device sends first indication information to the terminal device, where the first indication information is used to activate the TCI status of the candidate cell.

[0203] 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 information, which is not limited in this embodiment 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 among the multiple TCI states. The TCI state of the activated candidate cell is called the first TCI state. Regarding the first TCI state, it can also be called a semi-activated TCI state.

[0204] 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 whether 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 can 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.

[0205] 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.

[0206] 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).

[0207] In one possible implementation, the first TCI state includes the TCI state of the common beam, and the TCI state of the common beam is also called the 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 TRS or 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 the CSI-RS of the candidate cell, for example, the first CSI-RS and / or the second CSI-RS are the CSI-RS of the candidate cell.

[0208] Exemplarily, the first TCI state includes TCI state #1, TCI state #2, TCI state #3, TCI state #4, and TCI state #5.

[0209] 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.

[0210] 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).

[0211] In another possible implementation, the first TCI state also includes a TCI state in which the QCL information type 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.

[0212] 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.

[0213] S3. Measure the first SSB according to the first indication information to obtain a first measurement result.

[0214] 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.

[0215] 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 will be understood that when the first TCI state includes multiple TCI states, the first SSB refers to multiple SSBs.

[0216] Next, how to determine the first SSB is introduced according to the type of QCL information of the first TCI state.

[0217] In one 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 based on the QCL information of the first TCI state. Then, the terminal device determines the TCI state corresponding to the CSI-RS based on the configuration information of the at least one CSI-RS. For the sake of convenience, this 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 for receiving 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. The QCL type of the third TCI state is type C and / or type D.

[0218] In another possible implementation, when the first TCI state also includes a fourth TCI state, QCL information of the fourth TCI state is determined based on the first indication information. Then, the first SSB is determined based on the QCL information of the fourth TCI state, where the QCL information of the fourth TCI state includes index information of the first SSB.

[0219] 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:

[0220] Measuring the clock offset compensation and / or frequency domain offset compensation and / or receive beam determined by the first SSB. The receive beam may refer to a spatial filter or receive spatial filter parameters (Rx spatial filter parameters) used by the terminal device to receive other signals based on receiving the first SSB.

[0221] Exemplarily, when the first SSB includes multiple SSBs, the terminal device measures multiple first measurement results corresponding to the multiple SSBs. The terminal device then associates the multiple first measurement results with the corresponding first TCI states and stores them. For example, as shown in Table 1:

[0222] Table 1

[0223] S4. Receive a switching command, where the switching command is used to indicate a second TCI state.

[0224] 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.

[0225] Exemplarily, if the first indication information in step S2 is used to activate the TCI status of multiple candidate cells, the handover 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 handover 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 status indicated by the handover command belongs to cell #2.

[0226] 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.

[0227] Exemplarily, the type of QCL information regarding 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.

[0228] Exemplarily, the handover command is carried in a Media Access Control Layer Control Element MAC CE message.

[0229] 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.

[0230] In step S5, in response to the handover command, a first measurement result corresponding to the second TCI state is determined based on the second TCI state indicated by the handover command. Then, based on 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:

[0231] Based on the clock offset compensation and / or frequency domain offset compensation determined by measuring the first SSB, and / or the receive beam, a reference signal corresponding to the second TCI state is received. The reference signal may be a TRS signal or a CSI-RS signal.

[0232] Optionally, before step S5, the terminal device determines, based on the first measurement result, the TCI corresponding to the first SSB as a default beam. The default beam is used to transmit signals to the serving cell after the handover, and the serving cell after the handover is a candidate cell. By using the default beam to transmit signals, the terminal device communication time is reduced and the communication quality of the terminal device is improved.

[0233] Optionally, the TCI corresponding to the reference signal in the first TCI state is not allowed to be indicated by a handover 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 handover command. The TCI corresponding to the reference signal in the first TCI state is not allowed to be indicated by a handover command. This can also be understood as: the TCI indicated by the handover command does not include the TCI corresponding to the reference signal in the first TCI state, and the TCI activated by the handover command is used for data transmission. The reference signal includes but is not limited to: a TRS or a CSI-RS.

[0234] S6. Activate the second TCI state according to the second measurement result.

[0235] In step S6, after the terminal device obtains the second measurement result, 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.

[0236] 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, 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.

[0237] In conjunction with the aforementioned embodiments, the beam-based communication method proposed in the embodiments of the present application can also be used to determine a default beam, which is used for signal transmission between the terminal device and the serving cell after switching. Please refer to Figure 5, which is a flow chart of another embodiment of a beam-based communication method in the embodiments of the present application. The beam-based communication method proposed in the embodiments of the present application further includes:

[0238] F1. The terminal device receives a switching command from the network device.

[0239] 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.

[0240] Exemplarily, the handover command is carried in a Media Access Control Layer Control Element MAC CE message.

[0241] There are many possible ways to switch commands, which are described below:

[0242] 1. The timing advance (TA) is not indicated in the handover command.

[0243] 2. The Transmission Configuration Indicator (TCI) is not indicated in the handover command. The TCI is not indicated in the handover command, which includes the TCI not being explicitly indicated in the handover command.

[0244] 3. TCI is indicated in the switching command.

[0245] 4. Indicate TA in the switching command.

[0246] F2. 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 service cell, and the switched service cell belongs to a candidate cell.

[0247] In step F2, after receiving the handover command, the terminal device detects whether the first condition is met based on 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 to the serving cell after the handover, and the serving cell after the handover is a candidate cell.

[0248] Specifically, the first condition includes: no transmission configuration indication TCI is indicated in the handover command, and the terminal device determines the TA based on the measurement result of the downlink reference signal;

[0249] Alternatively, if the timing advance TA is not indicated in the handover command, the terminal device determines the TA based on the measurement result of the downlink reference signal;

[0250] 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;

[0251] Alternatively, the handover command indicates a TA, and the terminal device determines that the TA of the candidate cell is 0;

[0252] Alternatively, the TCI indicated in the handover command is not activated in advance;

[0253] Alternatively, the source reference signal of the TCI indicated in the handover command includes a channel state information reference signal CSI-RS, and the terminal device does not measure the CSI-RS before receiving the handover command;

[0254] Alternatively, the handover command indicates TCI, and the terminal device feeds back a hybrid automatic repeat request response HARQ-ACK according to the handover command, and the time when the HARQ-ACK is fed back does not reach the beam effectiveness time point;

[0255] 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).

[0256] The terminal device determines the TA based on downlink reference signal measurement results, including: before the terminal device switches from the serving cell to the candidate cell, the network equipment of the serving cell configures the terminal device. 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. Based on this configuration information, the terminal device calculates the timing advance based on the time difference between the two SSB arrival times.

[0257] 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:

[0258] In one 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, and 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. Specifically, the terminal device determines the second SSB as the default beam, including:

[0259] In one 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 having 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 resource based on the second SSB of the candidate cell before switching and sends a preamble code, 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.

[0260] In one 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, where the second SSB is the QCL reference source signal in the TCI configuration of the CSI-RS.

[0261] In one possible implementation, the first condition is that no TCI is indicated in the handover command. If the terminal device determines the 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 handover 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.

[0262] 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 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 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.

[0263] 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.

[0264] Optionally, the second SSB is the SSB of the candidate cell most recently reported by the terminal device to the network device.

[0265] In another possible implementation, the terminal device determines, based on the handover command, a fifth TCI state indicated by the handover command; the terminal device determines the first reference signal as a default beam, or determines the synchronization signal block (SSB) associated with the first reference signal as the default beam, where the first reference signal is a reference signal indicated by quasi-co-site QCL information of the fifth TCI state. The QCL information of the fifth TCI state may be of type D. The first reference signal includes a CSI-RS or a TRS.

[0266] 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.

[0267] 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.

[0268] Optionally, a default beam is used for signal transmission in a primary cell, and a default beam is also used for signal transmission in a 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 cells indicated by a list of simultaneously updated beams, "simultaneousUTCI-Updatelist."

[0269] 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 the third synchronization signal block SSB based on 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.

[0270] Furthermore, the terminal device may also select a corresponding method to determine the default beam according to the first condition that is satisfied. Specifically,

[0271] 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 handover command does not indicate the transmission configuration indication TCI, and the terminal device determines the TA according to the measurement result of the downlink reference signal; or the handover command does not indicate the timing advance TA, and the terminal device determines the TA according to the measurement result of the downlink reference signal;

[0272] 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.

[0273] 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.

[0274] Optionally, the second SSB is the SSB of the candidate cell most recently reported by the terminal device to the network device.

[0275] 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;

[0276] 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.

[0277] 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.

[0278] 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;

[0279] The terminal device determines a default beam, including: 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.

[0280] 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;

[0281] 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.

[0282] 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.

[0283] 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 the third synchronization signal block SSB based on 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.

[0284] The present application is described above from the perspective of method, and other embodiments provided in the present application will be further described below.

[0285] Please refer to Figure 6, which is a schematic diagram of an implementation of the communication device provided in this application. 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 devices and / or network devices, etc.) in the above-mentioned method embodiments, and thus can also achieve the beneficial effects of the above-mentioned method embodiments. In the embodiments of the present application, the communication device 600 can be a terminal device and / or network device, or it can be an integrated circuit or component within the terminal device and / or network device, such as a chip.

[0286] The transceiver module 602 can implement corresponding communication functions and can also be called a communication interface or a communication unit, and is used to implement 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.

[0287] 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 implements any of the method embodiments shown in any of the aforementioned Figures 4-5.

[0288] The communication device 600 can be used to perform the actions performed by the communication device (terminal device or network device) in each of the above method embodiments. 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 of the above method embodiments, and the processing module 602 is used to perform the processing-related operations on the communication device side of the above method embodiments.

[0289] Optionally, the transceiver module 602 may include a sending module and a receiving module. The sending module is used to perform the sending operation of the communication device in each method embodiment shown in Figures 4 and 5. The receiving module is used to perform the receiving operation of the communication device in each method embodiment shown in Figures 4 and 5.

[0290] 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. The specific implementation depends on whether the above solution executed by the communication device 600 includes a sending action and a receiving action.

[0291] Please refer to Fig. 7, which is another schematic structural diagram of a communication device 700 provided in this application. 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.

[0292] Optionally, the communication device further includes a logic circuit 701.

[0293] The transceiver module 602 shown in FIG6 may be a communication interface, which may be the input / output interface 702 in FIG7 , which may include an input interface and an output interface. Alternatively, the communication interface may be a transceiver circuit, which may include an input interface circuit and an output interface circuit.

[0294] Optionally, when the communication device 700 is the session management function (or a component of the session management function) in the aforementioned embodiment, the input and output interface 702 is used to input and output information; the logic circuit 701 is used to execute the method executed by the terminal device and / or network device in the aforementioned Figures 4-5 and related embodiments.

[0295] 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.

[0296] In a possible implementation, the processing module 601 shown in FIG. 6 may be the logic circuit 701 in FIG. 7 .

[0297] Optionally, the logic circuit 701 may be a processing device, and the functions of the processing device may be partially or entirely implemented by software. The functions of the processing device may be partially or entirely implemented by software.

[0298] 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.

[0299] Alternatively, the processing device may include only a processor. A memory for storing the computer program is located outside the processing device, and the processor is connected to the memory via circuits / wires to read and execute the computer program stored in the memory. The memory and processor may be integrated or physically separate.

[0300] 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 (FPGAs), application-specific integrated circuits (ASICs), system-on-chips (SoCs), central processor units (CPUs), network processors (NPs), digital signal processors (DSPs), microcontroller units (MCUs), programmable logic devices (PLDs), or other integrated chips, or any combination of the above chips or processors.

[0301] Please refer to FIG8 , which shows a communication device 800 involved in the above embodiments provided in an embodiment of the present application. Specifically, the communication device 800 may be a communication device serving as a terminal device and / or a network device in the above embodiments.

[0302] Herein, a possible logical structure diagram of the communication device 800 is shown. The communication device 800 may include but is not limited to at least one processor 801 and a communication port 802 .

[0303] 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.

[0304] Furthermore, the processor 801 may be a central processing unit (CPU), a general-purpose processor (GPPC), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic device (PLD), a transistor logic device (TLD), a hardware component, or any combination thereof. It may implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this application. The processor may also be a combination that implements computing functions, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, and the like. Those skilled in the art will readily appreciate that, for ease and brevity of description, the specific operating processes of the systems, devices, and units described above may refer to the corresponding processes in the aforementioned method embodiments and will not be further elaborated upon herein.

[0305] It should be noted that the communication device 800 shown in Figure 8 can be specifically used to implement the steps implemented by the terminal device and / or network device in the aforementioned method embodiment, and to achieve the corresponding technical effects of the terminal device and / or network device. The specific implementation methods of the communication device shown in Figure 8 can refer to the description in the aforementioned method embodiment, and will not be repeated here.

[0306] Please refer to Figure 9, which is a schematic diagram of the structure of a communication device 900 involved in the above embodiments provided in an embodiment of the present application. The communication device 900 can specifically be a communication device used as a terminal device and / or a network device in the above embodiments. The structure of the communication device can refer to the structure shown in Figure 9.

[0307] 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, via 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.

[0308] Processor 901 is primarily used to process communication protocols and communication data, control the entire communication device, execute software programs, and process software program data, for example, to support the communication device in performing the actions described in the embodiments. The communication device may include a baseband processor and a central processing unit. The baseband processor is primarily used to process communication protocols and communication data, while the central processing unit is primarily used to control the entire terminal device, execute software programs, and process software program data. Processor 901 in Figure 9 may integrate the functions of both a baseband processor and a central processing unit. Those skilled in the art will appreciate that the baseband processor and the central processing unit may also be independent processors interconnected via a bus or other technology. Those skilled in the art will appreciate that a terminal device may include multiple baseband processors to accommodate different network standards, multiple central processing units to enhance its processing capabilities, and various components of the terminal device may be connected via various buses. The baseband processor may also be referred to as a baseband processing circuit or a baseband processing chip. The central processing unit may also be referred to as a central processing circuit or a central processing chip. The functionality for processing communication protocols and communication data may be built into the processor or stored in memory as a software program, which is executed by the processor to implement the baseband processing functionality.

[0309] The memory is primarily used to store software programs and data. Memory 902 can exist independently and be connected to processor 901. Alternatively, memory 902 can be integrated with processor 901, for example, within a single chip. Memory 902 can store program code for executing the technical solutions of the embodiments of the present application, and execution is controlled by processor 901. The various computer program codes executed can also be considered drivers for processor 901.

[0310] Figure 9 shows only one memory and one processor. 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. 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 present embodiment.

[0311] 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. 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 digital intermediate frequency signal to the processor 901 so that the processor 901 can further process the digital baseband signal or 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 digital intermediate frequency signal from the processor 901, convert the modulated digital baseband signal or 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 on the RF signal to obtain a digital baseband signal or a digital intermediate frequency signal. The order of the down-mixing and analog-to-digital conversion processes is adjustable. The transmitter Tx can selectively perform one or more stages of up-mixing and digital-to-analog conversion on the modulated digital baseband signal or digital intermediate frequency signal to obtain a RF signal. The order of the up-mixing and digital-to-analog conversion processes is adjustable. The digital baseband signal and the digital intermediate frequency signal may be collectively referred to as digital signals.

[0312] 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 that implements a receiving function may be referred to as a receiving unit, and a device in the transceiver module that implements a transmitting function may be referred to as a transmitting unit. That is, the transceiver module includes a receiving unit and a transmitting unit. The receiving unit may also be referred to as a receiver, an input port, a receiving circuit, etc., and the transmitting unit may be referred to as a transmitter, a transmitter, or a transmitting circuit, etc.

[0313] In the embodiments of the present application, the antenna and RF circuit with transceiver functions can be considered the transceiver 903 of the terminal device, and the processing unit with processing functions can be considered the processor 901 of the terminal device. As shown in Figure 9, the terminal device includes a transceiver 903 and a processor 901. The transceiver 903 can also be referred to as a transceiver unit, a transceiver, a transceiver device, etc. The processor 901 can also be referred to as a processing unit, a processing board, a processing module, a processing device, etc.

[0314] Alternatively, the device in transceiver 903 that implements the receiving function may be referred to as a receiving unit, and the device in transceiver 903 that implements the transmitting function may be referred to as a transmitting unit. That is, transceiver 903 includes a receiving unit and a transmitting unit. The transceiver unit may also be referred to as a transceiver, a transceiver circuit, etc. The receiving unit may also be referred to as a receiver, a receiver, or a receiving circuit, etc. The transmitting unit may also be referred to as a transmitter, a transmitter, or a transmitting circuit, etc.

[0315] It should be understood that the transceiver 903 is used to perform the 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 other than the sending and receiving operations on the communication device (terminal device or network device) in the above-mentioned method embodiments.

[0316] 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, microprocessor, integrated circuit, or logic circuit integrated on the chip.

[0317] It should be noted that the communication device 900 shown in Figure 9 can be specifically used to implement the steps implemented by the terminal device and / or network device in the aforementioned method embodiment, and to achieve the corresponding technical effects of the terminal device and / or network device. The specific implementation methods of the communication device 900 shown in Figure 9 can refer to the description in the aforementioned method embodiment, and will not be repeated here.

[0318] 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.

[0319] 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 method of the above-mentioned terminal device or network device.

[0320] An 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 a chip, or it can include a chip and other discrete devices, wherein the communication device can specifically be a terminal device or a network device in the aforementioned method embodiment.

[0321] 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.

[0322] In the several embodiments provided in this 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 merely schematic. For example, the division of the unit is only a logical function division. In actual implementation, there may be other division methods, 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 interface, device or unit, which can be electrical, mechanical or other forms.

[0323] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to achieve the purpose of the solution of this embodiment according to actual needs.

[0324] In addition, the functional units in the various embodiments 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 contributing part 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 enabling a computer device (which can be a personal computer, a server, or a wireless access network, etc.) to execute all or part of the steps of the method of each embodiment of the present application. The aforementioned storage medium includes various media that can store program code, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

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. The communication device according to claim 17, characterized in that: 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; 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; The processing module is further used to activate the second TCI state according to the second measurement result.

19. The communication device according to claim 17 or 18, characterized in that: The processing module is further used to determine the QCL information of the first TCI state according to the first indication information; 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; 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; 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; The processing module is also used to measure the first SSB to obtain the first measurement result.

20. The communication device according to claim 19, characterized in that The quasi co-site QCL types of the third TCI state are type C and type D.

21. The communication device according to any one of claims 17 to 20, 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.

22. The communication device according to claim 21, characterized in that The processing module is further configured to determine the QCL information of the fourth TCI state according to the first indication information, wherein the QCL information of the fourth TCI state indicates that the source reference signal of the fourth TCI state includes SSB; 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; The processing module is also used to measure the first SSB to obtain the first measurement result.

23. The communication device according to any one of claims 17 to 22, characterized in that: 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 relevant information of the CSI-RS of the candidate cell.

24. The communication device according to any one of claims 17 to 23, characterized in that: 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.

25. The communication device according to any one of claims 17 to 24, 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.

26. 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.

27. The communication device according to claim 26, characterized in that The processing module is further configured to determine the default beam when one or more of the following conditions of the first condition are met: The first condition includes: the handover command does not indicate a transmission configuration indication TCI, and the terminal device determines the TA according to the measurement result of the downlink reference signal; or the handover command does not indicate a timing advance TA, and the terminal device determines the TA according to the measurement result of the downlink reference signal. Determine TA based on the measurement results; The processing module is also used to determine 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.

28. The communication device according to claim 27, characterized in that The processing module is further configured to determine the default beam when one or more of the following conditions of the first condition are met: 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 processing module is further configured to determine, according to the switching command, a fifth TCI state indicated by the switching command; 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.

29. The communication device according to claim 28, 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.

30. The communication device according to claim 27, characterized in that The processing module is further configured to determine the default beam when one or more of the following conditions of the first condition are met: 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 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; The processing module is further used to determine the SSB with the largest reference signal receiving power as the default beam.

31. The communication device according to claim 27, characterized in that: The processing module is further used for: 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; Determine to measure the synchronization signal block SSB of the TA of the primary cell as the default beam.

32. The communication device according to claim 30, 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.

33. 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.

34. A communication device, characterized in that: including a processor and memory, The memory is used to store computer programs or computer programs or instructions; The processor is used to execute the computer program or computer program or instruction 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.

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

36. 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.

37. 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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