This application relates to the field of communications technologies and discloses a transmitter device and a signal processing method. m transmit antenna groups of the transmitter are configured to send m training signals under control of the processor. A target feedback antenna of the transmitter is configured to receive, under control of the processor, a first mixed signal obtained by superimposing the m training signals in space, where a phase difference between the first mixed signal and a second mixed signal obtained by superimposing in space the m training signals received by a receiver device falls within a preset range. A processor of the transmitter is configured to: perform DPD parameter estimation and pre-distortion processing on a to-be-sent signal. The m transmit antenna groups are further configured to send, under control of the processor, the to-be-sent signal on which pre-distortion processing has been performed.