Method for sending control information, apparatus, and system

A method for detecting control information, the method comprising:

• determining, by a user terminal, at least one information field comprised in first control information based on a first time-frequency domain resource for detecting the first control information;
• determining, by the user terminal, a quantity of bits of the first control information based on the at least one information field;
• detecting, by the user terminal, the first control information on the first time-frequency domain resource based on the quantity of bits of the first control information;
• and
• receiving, by the user terminal, the first control information after detecting the first control information.

A network device, comprising:

• a processor, configured to:
• determine, based on a first time-frequency domain resource for sending first control information, at least one information field comprised in the first control information;
• and
• determine a quantity of bits of the first control information based on the at least one information field;
• and
• a sending circuit, configured to send the first control information to a user terminal on the first time-frequency domain resource based on the quantity of bits of the first control information.

A user terminal, comprising:

• a processor, configured to:
• determine, based on a first time-frequency domain resource for detecting first control information, at least one information field comprised in the first control information;
• wherein
• determine a quantity of bits of the first control information based on the at least one information field;
• detect the first control information on the first time-frequency domain resource based on the quantity of bits of the first control information;
• and
• a receiving circuit, configured to receive the first control information after the processor detects the first control information.