1. An uplink data transmission method for negotiating data encoding and modulation schemes for uplink data carried on a data time-frequency resource from a terminal to a network device, wherein the method comprises:encoding and modulating, by the terminal device, control information according to control encoding and modulation schemes to obtain a control symbol,
wherein the control encoding and modulation schemes are agreed upon between the terminal and the network device receiving the control symbol and the control information indicates a data encoding scheme;
encoding and modulating, by the terminal device, uplink data according to the data encoding scheme indicated by the control symbol;
sending the control symbol to a network device by using a control time-frequency resource, wherein the control symbol is for use by the network device in negotiating a decoding scheme for the data symbol; and
sending the data symbol to the network device by using the data time-frequency resource different from the control time-frequency resource,
wherein the control and data time-frequency resources belong to a transmission resource for uplink transmission of the control and data symbols, respectively, from the terminal to the network device without prior notification from the network device.