The present disclosure relates to signal sending methods and apparatuses. One example method includes determining, based on a quantity T of transmit antennas of a radar and a quantity NC of signals transmitted through each transmit antenna in a frame, T codeword sequences that are in a one-to-one correspondence with T transmit antennas, where each of the T codeword sequences includes NC codewords, each codeword sequence is used to process NC signals of a transmit antenna, T>1, NC≥1, both T and NC are integers, a Doppler spectrum corresponding to the T codeword sequences includes a first region corresponding to a main lobe, and a second region and a third region that correspond to side lobes, and a maximum peak value of the side lobe in the second region is less than a maximum peak value of the side lobe in the third region.