The communication method includes: sending, by a CMTS (cable modem terminals stem), a reference signal within a first time period by using a valid subcarrier in a first spectrum, where the first time period is a time period within which none of CMs (cable modems) connected to the CMTS sends a signal in the first spectrum; performing, by the CMTS based on an interfering signal received by the CMTS within the first time period, channel interference estimation on a channel that is used during signal reception of the CMTS and that occupies the first spectrum, where the interfering signal is a signal obtained after the reference signal passes through the channel; and canceling, by the CMTS based on a result of the channel interference estimation, interference from a first signal received by the CMTS to a second signal received by the CMTS.