Control information obtaining method and apparatus
The present disclosure relates to control information sending methods in a wireless communications system. In one example waveform control information sending method, a network device obtains control information that includes uplink transmission waveform indication information, and sends the control information to a terminal. After receiving the control information, the terminal determines, based on the control information, a waveform used to send uplink data.
1. A control information sending method, wherein the method comprises:
generating, by a network device, first control information, wherein the first control information comprises first information indicating two uplink transmission waveforms, wherein the two uplink transmission waveforms are configured by the network device for a terminal to transmit uplink data to the network device, wherein the first control information is insufficient for the terminal to determine, from the two uplink transmission waveforms, a waveform used to transmit the uplink data to the network device, and wherein the two uplink transmission waveforms indicated by the first control information are an orthogonal frequency division multiplexing (OFDM) waveform and a discrete Fourier transform-spread orthogonal frequency division multiplexing (DFT-S-OFDM) waveform;
sending, by the network device, the first control information to the terminal;
generating, by the network device, second control information, wherein the second control information comprises second information indicating the terminal to use a particular uplink transmission waveform of the two uplink transmission waveforms comprised in the first control information; and
sending, by the network device, the second control information to the terminal.
2. The method according to claim 1 , wherein the first control information is radio resource control (RRC) signaling, and the second control information is downlink control information (DCI).
3. The method according to claim 1 , wherein the first control information is used to indicate the waveform used when the terminal transmits the uplink data for one time or for a plurality of times.
4. The method according to claim 1 , wherein the first information is transmission mode (TM) information, modulation and coding scheme (MCS) information or waveform and power control mixed information.
5. The method according to claim 1 , wherein the second information is at least one piece of power control information, and a cumulative power offset of the at least one piece of power control information is used by the terminal to determine a waveform.
6. A control information receiving method, wherein the method comprises:
receiving, by a terminal, first control information sent by a network device, wherein the first control information comprises first information indicating two uplink transmission waveforms, wherein the two uplink transmission waveforms are configured by the network device for the terminal to transmit uplink data to the network device, wherein the first control information is insufficient for the terminal to determine, from the two uplink transmission waveforms, a waveform used to transmit the uplink data to the network device, and wherein the two uplink transmission waveforms indicated by the first control information are an orthogonal frequency division multiplexing (OFDM) waveform and a discrete Fourier transform-spread orthogonal frequency division multiplexing (DFT-S-OFDM) waveform;
receiving, by the terminal, second control information sent by the network device, wherein the second control information comprises second information indicating the terminal to use a particular uplink transmission waveform of the two uplink transmission waveforms comprised in the first control information; and
determining, by the terminal based on the first control information and the second control information, the particular uplink transmission waveform as the waveform used to transmit the uplink data to the network device.
7. The method according to claim 6 , wherein the first control information is radio resource control (RRC) signaling, and the second control information is downlink control information (DCI).
8. The method according to claim 6 , wherein the first control information is used to indicate the waveform used when the terminal transmits the uplink data for one time or for a plurality of times.
9. The method according to claim 6 , wherein the first information is transmission mode (TM) information, modulation and coding scheme (MCS) information or waveform and power control mixed information.
10. The method according to claim 6 , wherein the second control information is downlink control information (DCI), and a length of the DCI indicates at least one uplink transmission waveform, or the DCI comprises one piece of waveform indication information.
11. The method according to claim 6 , wherein the second information is at least one piece of power control information, and a waveform of the terminal is determined by using both a cumulative power offset of the at least one piece of power control information and a power value set by the terminal.
12. A network device, wherein the network device comprises at least one processor, one or more memories, and a transmitter, and wherein the one or more memories stores programming instructions for execution by the at least one processor to:
generate first control information, wherein the first control information comprises first information indicating two uplink transmission waveforms, wherein the two uplink transmission waveforms are configured by the network device for a terminal to transmit uplink data to the network device, wherein the first control information is insufficient for the terminal to determine, from the two uplink transmission waveforms, a waveform used to transmit the uplink data to the network device, and wherein the two uplink transmission waveforms indicated by the first control information are an orthogonal frequency division multiplexing (OFDM) waveform and a discrete Fourier transform-spread orthogonal frequency division multiplexing (DFT-S-OFDM) waveform;
send, using the transmitter, the first control information to the terminal;
generate second control information, wherein the second control information comprises second information indicating the terminal to use a particular uplink transmission waveform of the two uplink transmission waveforms comprised in the first control information; and
send, using the transmitter, the second control information to the terminal.
13. The network device according to claim 12 , wherein the first control information is radio resource control (RRC) signaling, and the second control information is downlink control information (DCI).
14. A terminal, comprising a receiver, one or more memories, and at least one processor, wherein:
the receiver is configured to:
receive first control information sent by a network device, wherein the first control information comprises first information indicating two uplink transmission waveforms, wherein the two uplink transmission waveforms are configured by the network device for the terminal to transmit uplink data to the network device, wherein the first control information is insufficient for the terminal to determine, from the two uplink transmission waveforms, a waveform used to transmit the uplink data to the network device, and wherein the two uplink transmission waveforms indicated by the first control information are an orthogonal frequency division multiplexing (OFDM) waveform and a discrete Fourier transform-spread orthogonal frequency division multiplexing (DFT-S-OFDM) waveform; and
receive second control information sent by the network device, wherein the second control information comprises second information indicating the terminal to use a particular uplink transmission waveform of the two uplink transmission waveforms comprised in the first control information; and
the one or more memories stores programming instructions for execution by the at least one processor to determine, based on the first control information and the second control information, the particular uplink transmission waveform as the waveform used to send the uplink data.
15. The terminal according to claim 14 , wherein the first control information is radio resource control (RRC) signaling, and the second control information is downlink control information (DCI).
16. The method according to claim 1 , wherein the second control information is radio resource control (RRC) signaling or a media access control-control element (MAC CE).
17. The method according to claim 6 , wherein the second control information is radio resource control (RRC) signaling or a media access control-control element (MAC CE).
18. The network device according to claim 12 , wherein the second control information is radio resource control (RRC) signaling or a media access control-control element (MAC CE).
19. The method according to claim 1 , wherein the terminal is unable to determine the waveform to send the uplink data based on the first information without the second information.
20. A control information sending method, wherein the method comprises:
generating, by a network device, first control information, wherein the first control information comprises first information indicating two uplink transmission waveforms, wherein the two uplink transmission waveforms are configured by the network device for a terminal to transmit uplink data to the network device, and wherein the two uplink transmission waveforms indicated by the first control information are an orthogonal frequency division multiplexing (OFDM) waveform and a discrete Fourier transform-spread orthogonal frequency division multiplexing (DFT-S-OFDM) waveform;
sending, by the network device, the first control information to the terminal;
generating, by the network device, second control information, wherein the second control information comprises second information indicating the terminal to use a particular uplink transmission waveform of the two uplink transmission waveforms comprised in the first control information, the second control information is downlink control information (DCI), and a length of the DCI indicates at least one uplink transmission waveform; and
sending, by the network device, the second control information to the terminal.