The present invention relates to the field of wireless communications, and in particular, to a method for transmitting a reference signal, a method for determining a phase noise, and related apparatuses, to resolve the problem in the prior art that different phase noises of different antenna units or antenna ports of a transmitter cannot be accurately estimated and compensated for. The method comprises: the transmitter respectively transmitting each precoded DMRS and PTRS to a receiver via respective corresponding antenna groups having a same phase noise, and when the receiver receives the PTRS, performing channel estimation based on each received PTRS, to determine phase changes caused by phase noises corresponding to different antenna groups. In this way, even if different antennas of a transmitter have different phase noises, phase changes caused by the different phase noises can still be accurately determined, so that all data transmitted by the different antenna groups can be accurately demodulated according to different phase changes.