A receiver receiving an optical signal transmitted by a fiber communication system, comprising: two first input ends (111, 112), a despreading module, a multiple-input multiple-output equalization module, and 2N first output ends (1411, 1421, 1412, 1422, 141N, 142N), wherein the two first input ends (111, 112) are connected to the despreading module, and the despreading module is connected to the multiple-input multiple-output equalization module; the two first input ends (111, 112) are configured to respectively receive a digital signal of an X-polarization state and a digital signal of a Y-polarization state, the optical signal being split, by a polarization beam splitter of the receiver, into a first optical signal in an X-polarization state and a second optical signal in an Y-polarization state, and the first and second optical signal being processed by the receiver respectively into the digital signal of a X-polarization state and the digital signal of a Y-polarization state; the despreading module is configured to despread the digital signal of the X-polarization state and the digital signal of the Y-polarization state based on N delay values and spreading codes of N transmitters, to obtain N first baseband signals and N second baseband signals, wherein each first baseband signal comprises a first baseband signal of the X-polarization state and a first baseband signal of the Y-polarization state, each second baseband signal comprises a second baseband signal of the X-polarization state and a second baseband signal of the Y-polarization state, and the N delay values are respectively determined based on differences between synchronization positions of first polarization states and synchronization positions of second polarization states of the N transmitters; the multiple-input multiple-output equalization module is configured to perform equalization filtering processing on the N first baseband signals and the N second baseband signals, to obtain recovered data of the first polarization states and recovered data of the second polarization states of the N transmitters; and the 2N first output ends (1411, 1421, 1412, 1422, 141N, 142N) each are configured to output recovered data of one polarization state of one transmitter, wherein N is a positive integer greater than 1. two first input ends (111, 112), a despreading module, a multiple-input multiple-output equalization module, and 2N first output ends (1411, 1421, 1412, 1422, 141N, 142N), wherein the two first input ends (111, 112) are connected to the despreading module, and the despreading module is connected to the multiple-input multiple-output equalization module; the two first input ends (111, 112) are configured to respectively receive a digital signal of an X-polarization state and a digital signal of a Y-polarization state, the optical signal being split, by a polarization beam splitter of the receiver, into a first optical signal in an X-polarization state and a second optical signal in an Y-polarization state, and the first and second optical signal being processed by the receiver respectively into the digital signal of a X-polarization state and the digital signal of a Y-polarization state; the despreading module is configured to despread the digital signal of the X-polarization state and the digital signal of the Y-polarization state based on N delay values and spreading codes of N transmitters, to obtain N first baseband signals and N second baseband signals, wherein each first baseband signal comprises a first baseband signal of the X-polarization state and a first baseband signal of the Y-polarization state, each second baseband signal comprises a second baseband signal of the X-polarization state and a second baseband signal of the Y-polarization state, and the N delay values are respectively determined based on differences between synchronization positions of first polarization states and synchronization positions of second polarization states of the N transmitters; the multiple-input multiple-output equalization module is configured to perform equalization filtering processing on the N first baseband signals and the N second baseband signals, to obtain recovered data of the first polarization states and recovered data of the second polarization states of the N transmitters; and the 2N first output ends (1411, 1421, 1412, 1422, 141N, 142N) each are configured to output recovered data of one polarization state of one transmitter, wherein N is a positive integer greater than 1.