Communication method

The invention provides a communication method. The downlink communication operation of the communication method includes: an optical network unit receives an optical signal sent from an optical line terminal, and converts the optical signal into a digital signal, and sends the digital signal to a head end device; the head end device receives the digital signal and converts the digital signal into a carrier signal and sends the carrier signal to a repeater device; the repeater device receives the carrier signal sent from the head end device, and performs gain for the carrier signal, and sends the carrier signal after gain to a terminal device; and the terminal device receives the carrier signal, sent from the repeater device, after gain, and converts the carrier signal after gain into a digital signal, and sends the digital signal to a first user terminal.