| 摘要 |
The present invention relates to the field of mobile communications technologies, and discloses methods and apparatuses for sending and receiving a signal, and a system, which are used to resolve a problem that during signal transmission, digital signal quality is relatively poor and implementation costs are relatively high. The methods for sending and receiving a signal are specifically: splitting a received digital signal into a first digital signal and a second digital signal, respectively converting the first digital signal and the second digital signal into an analog in-phase signal and an analog quadrature signal, respectively modulating the analog in-phase signal and the analog quadrature signal to two optical signals that are perpendicular to each other and are in a polarization state, combining, into one optical signal, the two optical signals that are perpendicular to each other and are in a polarization state, and sending the optical signal to an ONU; and performing, by the ONU, corresponding demodulation on the optical signal, and sending the optical signal to a user terminal. In this way, the problem that during signal transmission, digital signal quality is relatively poor and implementation costs are relatively high is resolved. |
