Abstract: A clock synchronization method and a communication apparatus are provided. The method includes: multiplexing a local analog clock signal and a first data signal to obtain a first multiplexed signal; sending the first multiplexed signal to a first apparatus; receiving a second multiplexed signal from the first apparatus; demultiplexing the second multiplexed signal to obtain a second data signal and a first analog clock signal, where the first analog clock signal corresponds to the local analog clock signal after it has gone through a transmission delay; obtaining a first signal based on the first analog clock signal, where the first signal is a delay compensation amount or a second analog clock signal, and the second analog clock signal is obtained by applying delay compensation to the local analog clock signal; and processing data based on the first signal to obtain the first data signal, to which delay compensation has been applied.

Abstract: This application provides an example wireless center device and an example wireless device for delay measurement, and an example wireless communication system. The example wireless center device includes a delay measurement circuit, configured to obtain a first clock signal of the wireless center device, and a modem configured to send a first optical wave and a second optical wave to the wireless device through a fiber link, where the first optical wave carries the first clock signal, receive the second optical wave that is sent by the wireless device and that carries a second clock signal, receive a second sub optical wave reflected by the wireless device to obtain the second clock signal carried by the second optical wave and a first clock signal carried by the second sub optical wave, and send the second clock signal and the first clock signal to the delay measurement circuit.

Abstract: This application provides an example wireless center device and an example wireless device for delay measurement, and an example wireless communication system. The example wireless center device includes a delay measurement circuit, configured to obtain a first clock signal of the wireless center device, and a modem configured to send a first optical wave and a second optical wave to the wireless device through a fiber link, where the first optical wave carries the first clock signal, receive the second optical wave that is sent by the wireless device and that carries a second clock signal, receive a second sub optical wave reflected by the wireless device to obtain the second clock signal carried by the second optical wave and a first clock signal carried by the second sub optical wave, and send the second clock signal and the first clock signal to the delay measurement circuit.