Abstract: Embodiments of this application provide an antenna switching method for a terminal device and an apparatus. The terminal device sends detection packets through at least two antennas within uplink estimated time, obtains, based on response messages corresponding to the detection packets, spectrum effectiveness that is of the at least two antennas and that is within the uplink estimated time, and switches a current transmit antenna of the terminal device based on the spectrum effectiveness of the at least two antennas. In this manner, the terminal device determines, based on the uplink spectrum effectiveness of the at least two antennas, whether to switch the current transmit antenna. Because the uplink spectrum effectiveness of the antennas can accurately reflect a real environment of uplink transmission, antenna switching can be accurately performed. This improves performance of an uplink transmit antenna.

Abstract: An in-device coexistence (IDC) indication message sending method includes a network device determining, when configuration information sent by the network device indicates that the terminal device can send an IDC indication message, a most proper IDC interference cancellation manner based on SUL frequency information, a type of an interfering frequency, a transmit power of the terminal device, a transmit power of the network device, a priority of a frequency band in which the interfering frequency is located, or an IDC interference cancellation manner expected by the terminal device that are indicated by the IDC indication message sent by the terminal device.

Abstract: This application provides a data sending method and a terminal device. A plurality of antennas are configured for the terminal device, the plurality of antennas are configured to alternately send SRSs, the plurality of antennas include a first antenna and a second antenna. The terminal device determines to send a first SRS using the first antenna at a first moment; determines to send a second SRS using the second antenna at a second moment which is after the first moment; and determines to send first service data using the first antenna at a third moment which is after the second moment. The terminal device adjusts a transmit antenna of the first SRS as the second antenna, and adjusts a transmit antenna of the second SRS as the first antenna, to enable the transmit antenna of the second SRS to be consistent with a transmit antenna of the first service data.

Abstract: This application provides a transmit power control method, a terminal, a chip system, and a system. The method includes: A terminal connects to a 4G network device over an LTE link and connects to a 5G network device over an NR link, where transmit power of the NR link is first transmit power; determines to send a first data packet over the NR link, where the first data packet is a preset data packet; adjusts the first transmit power to second transmit power, where the second transmit power is greater than the first transmit power; and sends the first data packet at the second transmit power over the NR link.

Abstract: This application provides example methods for controlling an output power of an antenna for user equipment. One example method includes, during a sounding reference signal (SRS) transmission period, transmitting, by a first antenna of at least one antenna of the user equipment, a first SRS signal to a base station at a first SRS output power, where the first SRS output power is equal to a maximum output power (Pcmax) of the first antenna. During the SRS period, a non-SRS signal is transmitted to the base station at a non-SRS output power, where the non-SRS output power is less than a difference between the maximum output power of the first antenna and a maximum output power reduction of the first antenna, and the maximum output power reduction of the first antenna is set to meet an electromagnetic power density exposure requirement of the first antenna.

Abstract: This application provides a method for dynamically switching antennas. User equipment determines an antenna switching sequence based on a networking mode of the user equipment and an actual scenario, and performs antenna switching based on the determined antenna switching sequence. When the technical solutions of this application are implemented, a problem that a conflict exists in an antenna switching process is effectively resolved without adding hardware.

Abstract: This application provides a communication method in a dual-connectivity mode. In the communication method, maximum transmit power used by a terminal device to send a message corresponding to a main network protocol in a semi-persistent power sharing mode is maximum transmit power 2, maximum transmit power used by the terminal device to send a message corresponding to a secondary network protocol is maximum transmit power 3, the maximum transmit power 2 is less than theoretical maximum transmit power corresponding to the main network protocol, and the maximum transmit power 3 is greater than the theoretical maximum transmit power corresponding to the main network protocol.

Abstract: A transmit power control method includes obtaining an uplink-downlink configuration (uplink (UL)/downlink (DL) assignment) from a network side and determining a power decrease that can be reduced in the uplink-downlink configuration compared with that in an all-uplink configuration when and uplink time proportion configured in the uplink-downlink configuration is not 100% and the uplink-downlink configuration is not the all-uplink configuration.

Abstract: Embodiments of this application provide an antenna switching method for a terminal device and an apparatus. The terminal device sends detection packets through at least two antennas within uplink estimated time, obtains, based on response messages corresponding to the detection packets, spectrum effectiveness that is of the at least two antennas and that is within the uplink estimated time, and switches a current transmit antenna of the terminal device based on the spectrum effectiveness of the at least two antennas. In this manner, the terminal device determines, based on the uplink spectrum effectiveness of the at least two antennas, whether to switch the current transmit antenna. Because the uplink spectrum effectiveness of the antennas can accurately reflect a real environment of uplink transmission, antenna switching can be accurately performed. This improves performance of an uplink transmit antenna.

Abstract: A communication method includes determining, by a terminal device, first in-device coexistence (IDC) interference adjustment information, where the first IDC interference adjustment information includes frequency bandwidth information, and sending, by the terminal device sends, the first IDC interference adjustment information to a network device to adjust IDC interference based on the first IDC interference adjustment information.

Abstract: An in-device coexistence (IDC) indication message sending method includes a network device determining, when configuration information sent by the network device indicates that the terminal device can send an IDC indication message, a most proper IDC interference cancellation manner based on SUL frequency information, a type of an interfering frequency, a transmit power of the terminal device, a transmit power of the network device, a priority of a frequency band in which the interfering frequency is located, or an IDC interference cancellation manner expected by the terminal device that are indicated by the IDC indication message sent by the terminal device.

Abstract: Disclosed are a method for transmitting a synchronization channel SCH and a related device. The method include: configuring at least two SCH resources on a first common control channel and an extended control channel of a synchronization transmission period, where the synchronization transmission period includes 10 or 11 Time Division Multiple Access TDMA frames, each TDMA frame includes a total of 8 timeslots from timeslot 0 to timeslot 7, the first common control channel is timeslot 0, the extended control channel does not include timeslot 0, and each SCH resource is a timeslot of a TDMA frame; and transmitting at least two pieces of SCH information on the configured at least two SCH resources, where one piece of SCH information is transmitted on each SCH resource, and the at least two pieces of SCH information include same frame number information.

Abstract: Disclosed are a method for transmitting a synchronization channel SCH and a related device. The method include: configuring at least two SCH resources on a first common control channel and an extended control channel of a synchronization transmission period, where the synchronization transmission period includes 10 or 11 Time Division Multiple Access TDMA frames, each TDMA frame includes a total of 8 timeslots from timeslot 0 to timeslot 7, the first common control channel is timeslot 0, the extended control channel does not include timeslot 0, and each SCH resource is a timeslot of a TDMA frame; and transmitting at least two pieces of SCH information on the configured at least two SCH resources, where one piece of SCH information is transmitted on each SCH resource, and the at least two pieces of SCH information include same frame number information.