Abstract: This application discloses a modulation method, a demodulation method, and a communication apparatus, and relates to the field of communication technologies. The communication apparatus may obtain information bit sequences, divide the information bit sequences into G groups, then separately encode each group of information bit sequences to obtain r encoded bit sequences, map the r encoded bit sequences into a modulation symbol sequence, and output the modulation symbol sequence. The modulation method provided in embodiments of this application may implement a flexible compromise between complexity and robustness, and has a wider range of application.