DIFFERENTIAL QUADRATURE PHASE SHIFT KEYING SYSTEM, METHOD, AND DEVICE
First Claim
1. A differential quadrature phase shift keying (DQPSK) system, comprising a transmitter, wherein the transmitter comprises:
- a pre-coder, configured to pre-code a first signal and a second signal according a predetermined encoding rule, and generate an in-phase signal and a quadrature signal;
a first modulator, configured to modulate the in-phase signal to generate a first differential phase shift keying (DPSK) signal;
a second modulator, configured to modulate the quadrature signal to generate a second DPSK signal; and
an interferometer, configured to;
perform a 90 degree phase shift on the first DPSK signal or the second DPSK signal, interfere with and overlap with the other DPSK signal to obtain a DQPSK signal, and send the DQPSK signal to a receiver.
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Accused Products
Abstract
A differential quadrature phase shift keying (DQPSK) system, method, and device are disclosed. The DQPSK system includes: a transmitter, configured to: pre-code an input first signal and second signal, and generate an in-phase signal and a quadrature signal; modulate the in-phase signal to generate a first differential phase shift keying (DPSK) signal, and modulate the quadrature signal to generate a second DPSK signal; perform a 90 degree phase shift on the first DPSK signal or the second DPSK signal, and interfere with the other DPSK signal to obtain a DQPSK signal; and send the DQPSK signal to a receiver; the receiver, configured to: demodulate the DQPSK signal sent from the transmitter in detuned filter mode, and restore the first signal and the second signal through optical/electrical (o/E) conversion. With the present invention, the accurate control on the phase difference between two arms of an Asymmetric Mach-Zehnder Interferometer (AMZI) is avoided, thus facilitating the signal control and adjustment, and greatly lowering the system cost.
14 Citations
17 Claims
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1. A differential quadrature phase shift keying (DQPSK) system, comprising a transmitter, wherein the transmitter comprises:
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a pre-coder, configured to pre-code a first signal and a second signal according a predetermined encoding rule, and generate an in-phase signal and a quadrature signal; a first modulator, configured to modulate the in-phase signal to generate a first differential phase shift keying (DPSK) signal; a second modulator, configured to modulate the quadrature signal to generate a second DPSK signal; and an interferometer, configured to;
perform a 90 degree phase shift on the first DPSK signal or the second DPSK signal, interfere with and overlap with the other DPSK signal to obtain a DQPSK signal, and send the DQPSK signal to a receiver. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A differential quadrature phase shift keying (DQPSK) system, comprising:
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a transmitter, configured to;
pre-code N first signals and N second signals according to a predetermined encoding rule to generate N in-phase signals and N quadrature signals;
modulate the N in-phase signals to generate N first differential phase shift keying (DPSK) signals, and modulate the N quadrature signals to generate N second DPSK signals;
perform a 90 degree phase shift on the N first DPSK signals or the N second signals, and interfere with and overlap with the other N DPSK signals to obtain N DQPSK signals;
multiplex the N DQPSK signals into an N-channel DQPSK signal; and
send the N-channel DQPSK signal to a receiver; andthe receiver, configured to;
demultiplex the N-channel DQPSK signal sent from the transmitter into N DQPSK signals in detuned filter mode to restore the N first signals and the N second signals, wherein N is an integer greater than 1.
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12. A method for processing signals, comprising:
by a transmitter, pre-coding an input first signal and second signal, and generating an in-phase signal and a quadrature signal;
modulating the in-phase signal to generate a first differential phase shift keying (DPSK) signal, and modulating the quadrature signal to generate a second DPSK signal;
performing a 90 degree phase shift on the first DPSK signal or the second DPSK signal, and interfering with the other DPSK signal to obtain a differential quadrature phase shift keying (DQPSK) signal.- View Dependent Claims (13, 14, 15)
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16. A method for processing signals, comprising:
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by a transmitter, pre-coding input N first signals and N second signals, and generating N in-phase signals and N quadrature signals; modulating the N in-phase signals to generate N first non-return-to-zero differential phase shift keying (NRZ-DPSK) signals, and modulating the N quadrature signals to generate N second DPSK signals; and performing a 90 degree phase shift on the N DPSK signals or the N second DPSK signals, interfering with the other N DPSK signals to obtain N DQPSK signals, and multiplexing the N DQPSK signals into an N-channel DQPSK signal, wherein N is an integer greater than 1. - View Dependent Claims (17)
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Specification