In a possible design, the preset identifier corresponding to the user equipment includes a unique identifier pre-allocated to the user equipment, for example, a unique identifier is allocated to the user equipment based on a function of the DCI. Alternatively, the preset identifier corresponding to the user equipment is a group identifier that is pre-allocated to a group in which the user equipment is located.
A third aspect provides a feedback information transmission method, the feedback information transmission method is performed by a first device, and the first device may be user equipment or a network device. Optionally, the first device determines Q pieces of feedback information, where the Q pieces of feedback information are feedbacks for data that is carried by P data transmission units and received by the first device, Q is an integer greater than or equal to 2, P is greater than or equal to Q, and P is an integer.
The first device jointly codes the Q pieces of feedback information in a polar coding manner, to obtain one codeword, and then maps the codeword to a corresponding time-frequency resource for sending.
In a possible design, if the first device is a network device, the data carried by the P data transmission units is data sent by at least one user equipment to the network device, and the at least one user equipment is in same or similar channel conditions. In other words, the network device codes, into one codeword for feedback, feedback information of the at least one user equipment in same or similar channel conditions for data sent by the network device.
If the first device is user equipment, the data carried by the P data transmission units is data sent by a network device to the user equipment.