Patent ID: 11888529
Assignee: HUAWEI TECHNOLOGIES CO., LTD.
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 12:
13. A coherent transceiver system, comprising:
a light source configured to output an optical signal;
a coherent transmitter coupled to the light source and configured to output a modulated signal, wherein the coherent transmitter comprises:
a first signal modulator, wherein the first signal modulator comprises:
a first beam splitter, wherein the first beam splitter is configured to split a first optical signal to obtain a second optical signal and a third optical signal;
a first modulator coupled to the first beam splitter, wherein the first modulator is configured to modulate the second optical signal to obtain a first modulated signal;
a second modulator coupled to the first beam splitter, wherein the second modulator is configured to modulate the third optical signal to obtain a second modulated signal, and wherein the first modulated signal and the second modulated signal have a same phase;
a first phase shift adjuster coupled to the first modulator, wherein the first phase shift adjuster is configured to:
adjust a first phase of a first sub-signal in the first modulated signal, wherein there is a first phase difference between the first sub-signal and the first modulated signal; and
adjust a second phase of a fourth sub-signal in the first sub-signal, wherein there is a second phase difference between the fourth sub-signal and the first modulated signal, and wherein the second phase difference is twice as large as the first phase difference;

a first beam combiner coupled to the first phase shift adjuster, wherein the first beam combiner is configured to combine a second sub-signal in the first modulated signal and the fourth sub-signal to obtain a first combined signal; and
a second beam combiner coupled to the second modulator and the first phase shift adjuster, wherein the second beam combiner is configured to combine a third sub-signal in the first sub-signal and the second modulated signal to obtain a second combined signal, and wherein the modulated signal is the second combined signal;

a first photodiode (PD) coupled to the first signal modulator, wherein the first PD is configured to perform optical-to-electrical conversion on the first combined signal to obtain a first electrical signal; and
a controller coupled to the first signal modulator and the first PD, wherein the controller is configured to control, based on the first electrical signal, a first voltage applied to the first phase shift adjuster, to cause the first phase difference to fall within a preset range; and

a coherent receiver coupled to the coherent transmitter, wherein the coherent receiver is configured to:
mix the optical signal and the modulated signal to obtain a first mixed signal; and
demodulate the first mixed signal.