Waveform matching based optical digital signal receiving device

Patent metadata

Field	Value
Publication number	US-10797803-B2
Application number	US-201916686402-A
Country	US
Kind code	B2
Filing date	Nov 18, 2019
Priority date	Mar 29, 2018
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

A waveform matching based optical digital signal receiving device sequentially comprises an optical arbitrary waveform generator unit, an electro-optic modulator unit, an opto-electric converter unit, an electric filter unit, a sampling and judging module, a digital signal processing unit and a bit-timing extracting module. Accordingly, signal matched filtering, sampling and judgment can be effectively carried out in the optical domain, and the influence of noises on signal reception can be eliminated to the maximum extent, thereby achieving accurate detection and reception of signals. Meanwhile, compared with a conventional electric receiving device, the digital signal receiving device provided by the present invention breaks the limitation of “electronic bottleneck,” and greatly improves the bandwidth of signal reception, which allows digital signal reception at a higher speed.

First claim

We claim:

1. A waveform matching based optical digital signal receiving device, comprising
an optical arbitrary waveform generating module ( 1 ) for generating a periodic optical pulse sequence with an arbitrary pulse profile, the optical arbitrary waveform generating module ( 1 ) having an optical output direction, a control terminal, and a synchronous output terminal,
an electro-optic intensity modulator ( 2 ) having a modulation terminal,
an opto-electric converter ( 3 ),
an electric filter ( 4 ),
a sampling and judging module ( 5 ) having a judging threshold input terminal,
a digital signal processing unit ( 6 ) having a first output terminal, a second output terminal, a third output terminal, and
a bit-timing extracting module ( 7 ) having a first port, a second port, and a third port,
wherein the optical arbitrary waveform generating module ( 1 ), the electro-optic intensity modulator ( 2 ), the opto-electric converter ( 3 ), the electric filter ( 4 ), the sampling and judging module ( 5 ), and the digital signal processing unit ( 6 ) are sequentially arranged in the optical output direction of the optical arbitrary waveform generating module ( 1 ),
the first output terminal of the digital signal processing unit ( 6 ) is connected with the control terminal of the optical arbitrary waveform generating module ( 1 ),
the second output terminal of the digital signal processing unit ( 6 ) is connected with the judging threshold input terminal of the sampling and judging module ( 5 ),
the synchronous output terminal of the optical arbitrary waveform generating module ( 1 ) is connected with the first port of a bit-timing extracting module ( 7 ),
the second port of the bit-timing extracting module ( 7 ) is connected with the sampling and judging module ( 5 ),
the third port of the bit-timing extracting module ( 7 ) is connected with the third output terminal of the digital signal processing unit ( 6 ),
the bit-timing extracting module ( 7 ) receives control of the digital signal processing unit ( 6 ) through the third port to enable the sampling and judging module ( 5 ) to perform sampling and judgment at a peak value of an electrical filtered signal in each period, and a to-be-received signal is input into the modulation terminal of the electro-optic intensity modulator ( 2 ); and
wherein the optical arbitrary waveform generating module ( 1 ) generates the periodic optical pulse sequence with a controllable time-domain profile and a controllable phase according to the control of the digital signal processing unit ( 6 ), and the periodic optical pulse sequence is input into the electro-optic intensity modulator ( 2 );
the modulation terminal of the electro-optic intensity modulator ( 2 ) receives the to-be-received signal and outputs an optical pulse sequence modulated by the to-be-received signal;
the optical pulse sequence is firstly sent into the opto-electric converter ( 3 ) to be converted into an electrical signal, and then the electrical signal is sent into the electric filter ( 4 ) to be filtered;
the sampling and judging module ( 5 ) extracts a peak value of an output signal of the electric filter ( 4 ) in each period, and performs “0”-“1” judgment according to a judging threshold set by the digital signal processing unit ( 6 ); and
the digital signal processing unit ( 6 ) receives a judging result and processes the judging result to recover a digital signal sent by a sending terminal.

2. The waveform matching based optical digital signal receiving device according to claim 1 , wherein the optical pulse sequence generated by the optical arbitrary waveform generating module ( 1 ) has a period Ts identical to a period of the to-be-received signal,
the optical arbitrary waveform generating module ( 1 ) is controlled by the digital signal processing unit ( 6 ) to enable each single optical pulse to have a profile p.sub.s(t) similar to an electrical pulse waveform s1(t) of code “1” in the received digital signal,
wherein ps(t)=K1s1(t), K1 is a constant, and enables a phase of the output optical pulse sequence to coincide with a phase of a digital signal in the received signal within one period during electro-optic intensity modulation, and
the synchronous output terminal of the optical arbitrary waveform generating module ( 1 ) outputs a periodic signal with a period identical to the period of the generated optical pulse sequence.

3. The waveform matching based optical digital signal receiving device according to claim 1 , wherein the bit-timing extracting module ( 7 ) receives a periodic pulse signal output by the synchronous terminal of the arbitrary waveform generating module ( 1 ), performs phase adjustment and locking under control of the digital signal processing unit ( 6 ), and provides a sampling clock for the sampling and judging module ( 5 ) such that the sampling and judging module ( 5 ) performs sampling at the peak value of the filtered electrical signal in each period.

4. The waveform matching based optical digital signal receiving device according to claim 1 , wherein a time-domain width of an impulse response of the electric filter ( 4 ) is larger than a time-domain pulse width of each single optical pulse and smaller than a repetition period Ts of the optical pulse sequence, and a bandwidth of the electric filter ( 4 ) is smaller than a bandwidth of the opto-electric converter ( 3 ).

5. The waveform matching based optical digital signal receiving device according to claim 1 , wherein the judging threshold provided by the digital signal processing unit ( 6 ) to the sampling and judging module ( 5 ) takes an average value of code “1” and code “0” in a sampling result.

6. The waveform matching based optical digital signal receiving device according to claim 1 , wherein the optical pulse time-domain profile p s (t) is adjusted to make a system equivalent impulse response h A (t) approximately satisfy a matched filtering condition: h A (t)=Kp s (T s −t)=KK 1 s 1 (T s −t), wherein K is a constant.

Assignees

• Univ Shanghai Jiaotong

Inventors

• Wu Guiling
• Wang Sitong
• Sun Yiwei
• Chen Jianping

Classifications

• H04L7/0075

  with photonic or optical means · CPC title

• H04B10/695 Primary

  Arrangements for optimizing the decision element in the receiver, e.g. by using automatic threshold control · CPC title

• H04B10/63

  Homodyne {, i.e. coherent receivers where the local oscillator is locked in frequency and phase to the carrier signal} · CPC title

• H04B10/60

  Receivers · CPC title

• H04B10/50

  Transmitters · CPC title