Channel measurement method and precoding method and apparatus

An apparatus, comprising:

• at least one processor, and a memory storing instructions for execution by the at least one processor;
• wherein, when executed, the instructions cause the apparatus to perform operations comprising:
• receiving a plurality of reference signals in a plurality of first frequency domain units in a same time domain unit, wherein the plurality of reference signals are respectively precoded by using precoding matrices corresponding to the first frequency domain units in which the plurality of reference signals are located, and precoding matrices corresponding to at least two different first frequency domain units in the plurality of first frequency domain units are different;
• generating a precoding matrix indicator (PMI) based on the plurality of reference signals, wherein the PMI indicates a plurality of codewords corresponding to a plurality of second frequency domain units, the plurality of second frequency domain units and the plurality of first frequency domain units belong to a same frequency domain resource, and the plurality of codewords are used for determining a downlink channel;
• and
• sending the PMI.