Optical communication that achieves baud rate greater than sample rate
First Claim
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1. A method of optical communication, implemented at a transmitter in an optical communication network, comprising:
- receiving data bits for transmission over the optical communication network;
encoding the received data bits such that the encoded data bits are duo-binary comprising a zero level and two logical levels;
performing an M-point Fourier transform on the output of the duo-binary encoding, thereby producing M output signals;
generating, from the M output signals, N output signals by eliminating M-N signals representing highest frequency signals from the M output signals, wherein N is less than M;
producing time domain samples from the N output signals by performing an inverse Fourier transform; and
adding a cyclic prefix to the time domain samples for further processing the time domain samples for transmission over the optical communication network.
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Abstract
Duo-binary encoding is used for encoding I and Q data prior to performing orthogonal frequency division multiplexing based transmission using discrete Fourier transform spreading (DFT-S). Advantageously, duo-binary encoding improves robustness of the encoded signal to inter symbol interference, making the degradation caused by the subsequent DFT-S stage less susceptible to reduction in bit error rate performance.
1 Citation
26 Claims
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1. A method of optical communication, implemented at a transmitter in an optical communication network, comprising:
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receiving data bits for transmission over the optical communication network; encoding the received data bits such that the encoded data bits are duo-binary comprising a zero level and two logical levels; performing an M-point Fourier transform on the output of the duo-binary encoding, thereby producing M output signals; generating, from the M output signals, N output signals by eliminating M-N signals representing highest frequency signals from the M output signals, wherein N is less than M; producing time domain samples from the N output signals by performing an inverse Fourier transform; and adding a cyclic prefix to the time domain samples for further processing the time domain samples for transmission over the optical communication network. - View Dependent Claims (2, 3, 4)
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5. A method of recovering data from an orthogonal frequency division multiplexing (OFDM) modulated optical signal, implemented at an optical receiver, comprising:
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digitizing a received signal to generate digital samples of the OFDM modulated optical signal; transforming the digital samples using an N point Fourier transform to generate N intermediate output signals; spreading the N intermediate output signals into M signals by generating M-N signals having zero values, wherein M is an integer greater than N; producing time domain representation of symbols of modulated data by performing an M-point Fourier transform on the M signals; and performing decoding on the symbols of modulated data to recover data from the modulated optical signal. - View Dependent Claims (6, 7, 8, 9)
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10. An optical receiver for recovering data from an orthogonal frequency division multiplexing (OFDM) modulated optical signal comprising a digital signal processor that reads instructions from a computer-readable storage medium and implements a method, comprising:
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controlling a digitizer to digitize a received signal to generate digital samples of the OFDM modulated optical signal; transforming the digital samples using an N point Fourier transform to generate N intermediate output signals; spreading the N intermediate output signals into M signals by generating M−
N signals having zero values, wherein M is an integer greater than N;producing time domain representation of symbols of modulated data by performing an M-point Fourier transform on the M signals; and performing decoding on the symbols of modulated data to recover data from the modulated optical signal. - View Dependent Claims (11, 12, 13, 14)
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15. An optical communication system comprising an optical transmitter and at least one optical receiver, wherein the optical transmitter implements a method comprising:
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receiving data bits for transmission over the optical communication network, encoding the received data bits such that the encoded data bits are duo-binary comprising a zero level and two logical levels, performing an M-point Fourier transform on the output of the duo-binary encoding, thereby producing M output signals, generating, from the M output signals, N output signals by eliminating M−
N signals representing highest frequency signals from the M output signals, wherein N is less than M,producing time domain samples from the N output signals by performing an inverse Fourier transform, and adding a cyclic prefix to the time domain samples for further processing the time domain samples for transmission over the optical communication network; and the at least one optical receiver implements a method of recovering data, comprising; digitizing a received signal to generate digital samples of the OFDM modulated optical signal, transforming the digital samples using an N point Fourier transform to generate N intermediate output signals, spreading the N intermediate output signals into M signals by generating M−
N signals having zero values, wherein M is an integer greater than N,producing time domain representation of symbols of modulated data by performing an M-point Fourier transform on the M signals, and performing decoding on the symbols of modulated data to recover data from the modulated optical signal. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22)
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23. An optical transmitter for optical communication, comprising a digital signal processor that reads instructions from a computer-readable storage medium and is operable to:
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receive data bits for transmission over the optical communication network; encode the data bits such that the encoded data bits are duo-binary comprising a zero level and two logical levels; perform an M-point Fourier transform on the output of the duo-binary encoding, thereby producing M output signals; generate, from the M output signals, N output signals by eliminating M−
N signals representing highest frequency signals from the M output signals, wherein N is less than M;produce time domain samples from the N output signals by performing an inverse Fourier transform; and add a cyclic prefix to the time domain samples for further processing the time domain samples for transmission over the optical communication network. - View Dependent Claims (24, 25, 26)
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Specification