Communication method and apparatus

A communication apparatus, comprising a processor and a memory, wherein the processor is coupled to the memory, and the processor is configured to implement the following:

• receiving first compressed information from a terminal device, wherein the first compressed information is determined by the terminal device based on a first reference signal sent by an access network device using a first antenna activation mode, and the first compressed information represents first downlink channel information corresponding to an activated antenna port in the first antenna activation mode;
• and
• determining, based on the first compressed information and first information, second downlink channel information corresponding to a target antenna port, wherein the first information is determined based on at least one of a second reference signal or the first antenna activation mode, the target antenna port comprises an activated antenna port and an inactivated antenna port in the first antenna activation mode, and the second reference signal is a reference signal received by the access network device from the terminal device.