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Geometrically Shaped 32QAM and Modified Binary Switching Coding Method in Underwater Visible Light Communication

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Chinese Journal of Electronics 2022年第6期31卷 1106-1111页

作者： SHI Jianyang CAI Jifan QIN Guojin JIN Ruizhe LIN Xianhao CHI Nan Key Laboratory for Information Science of Electromagnetic Waves (MoE) Fudan University Peng Cheng Laboratory Shanghai Engineering Research Center of Low-Earth-Orbit Satellite Communication and Applications Shanghai Collaborative Innovation Center of Low-Earth-Orbit Satellite Communication Technology

Visible light communication(VLC) has emerged as a promising communication method in 6G,particularly in the domain of underwater ***, because of its intimate coupling to the lightemitting diodes(LED), the transmission rate is limited by the modulation bandwidth and the nonlinearity of the LED. With current device development, LED bandwidth is substantially lower than that of other optical communication devices, necessitating improved spectral efficiency and nonlinearity robustness to achieve high-speed transmission. In this paper, we propose a hexagonal constellation-based geometrically shaped(GS) 32QAM with carrierless amplitude and phase(CAP) modulation for the underwater VLC system. A comprehensive performance comparison of four GS modulation methods, including our proposed hexagonal-32QAM, normal 32QAM, square-32QAM and 32APSK is investigated in both theory and experiment. The hexagonal-32QAM with a modified binary switching coding(BSC) can obtain a Q factor gain of 0.44 dB, and a data rate improvement of 25 Mb/s compared with Gary coding based normal 32QAM. The experimentally results illustrate the feasibility of geometric shaping 32QAM in underwater visible light communication.

关键词： underwater VLC system comprehensive performance comparison modulation bandwidth amplitude shift keying carrierless amplitude and phase modulation light emitting diodes improved spectral efficiency Q factor gain communication method LED nonlinearity square-32QAM underwater visible light communication data rate improvement binary codes high-speed transmission light-emitting diodes hexagonal constellation-based geometrically shaped 32QAM quadrature amplitude modulation Gary coding based normal 32QAM free-space optical communication optical communication devices underwater optical wireless communication device development LED bandwidth optical modulation underwater communication geometric shaping 32QAM nonlinearity robustness GS modulation methods modified binary switching coding method BSC CAP phase modulation phase shift keying 32APSK hexagonal-32QAM

Generation of DQPSK format and its performance against polarization mode dispersion

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Chinese Optics Letters 2009年第1期7卷 15-18页

作者：何晶陈林文双春 School of Computer and Communication Hunan University

We propose a novel transmitter and receiver for differential quadrature phase-shift keying （DQPSK） format. The impact of the first-order polarization mode dispersion （PMD） on systems using DQPSK with 100- Gb/s non-return-to-zero （NRZ） or return-to-zero （RZ） format is investigated. Through computing the eye openings of DQPSK formats under different PMD conditions, it is found that NRZ DQPSK, as compared with RZ DQPSK, incurs smaller eye opening due to PMD. Carrier-suppressed return-to-zero （CSRZ） DQPSK format has better tolerance than RZ DQPSK format to PMD for a given bit rate.

关键词： Light transmission phase shift keying Polarization Polarization mode dispersion

An Optical Labeling Scheme with Novel DPSK/PPM Orthogonal Modulation

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Chinese Physics Letters 2010年第9期27卷 115-118页

作者：周锐忻向军王拥军张子兴余重秀 Key Laboratory of Information Photonics and Optical Communications (Ministry of Education) Beijing University of Posts and Telecommunications Beijing 100876

A novel differential-phase-shift-keying （DPSK）/pulse-position-modulation （PPM） orthogonal modulation is pro- posed for optical labeling applications, with PPM data as the high-speed payload and DPSK signal as the optical label. The systematic setup for the proposed scheme and research on bit-error rate is presented. The results show that at the bit-error rate of 10-~, the power penalties for 70kin fiber transmission are in the range of 1-3 dB to DPSK label and 5-6 dB to PPM payload in our simulation system. This is under the condition that the large extinction ratio of 18-19 dB is used for the intensity modulators of the PPM payload, with a well received DPSK label. Thus the feasibility of the proposed scheme for all optical transmission networks is clearly verified.

关键词： phase shift keying ORTHOGONALIZATION (Numerical analysis) OPTICAL fibers SIMULATION methods & models ERROR rates DATA transmission systems

Chinese Telemetry Technology under Fast Development

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Journal of Systems Engineering and Electronics 1993年第3期4卷 7-14页

作者： Changjie, Shi China Natl Space Administration Beijing China

The history of the development of Chinese telemetry is introduced in the paper. The new telemetry ground station and the new onboard space telemetry system, with the idea of systematic design and the specification, ar... 详细信息

关键词： Amplitude modulation Controllability History Parameter estimation phase shift keying Pulse code modulation Satellite ground stations Space applications Systems analysis Technology

Separation and insertion of optical bit-serial label in optical packet switching

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Chinese Optics Letters 2006年第3期4卷 138-140页

作者：凌云邱昆郑勉 Key Laboratory of Broadband Optical Fiber Transmission and Communication Networks University of Electronic Science and Technology of ChinaChengdu 610054

The bipolar phase-shift-keying （BPSK） optical orthogonal codes （OOCs） are inserted into the optical packet format of bit-serial label. The ultra-fast separation of the label and payload is performed through the auto-correlation pulses indicating the time position at whicl, the optical switch changes the state. The insertion of the new label can also be realized by detecting the auto-correlatiou pulse at the line rate. Especially, the scheme can be adapted to the asynchronous separation and insertion and realize the variable-length packet switching. The results of simulation verify the *** of the scheme.

关键词： Labels Optical correlation phase shift keying Separation Simulation

Performance evaluation of modulation formats in 40×40-Gb/s WDM repeaterless transmission systems

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Chinese Optics Letters 2006年第4期4卷 199-201页

作者：卢光山徐坤伍剑林金桐 Key Laboratory of Optical Communication and Lightwave Technologies Ministry of Education Beijing University of Posts and TelecommunicationsBeijing 100876

Transmission performance of six modulation formats is numerically compared in 40 × 40-Gb/s wavelength division multiplexing （WDM） repeaterless systems. The results indicate that return-to-zero differential phase shift keying （RZ-DPSK）（33% duty cycle） demonstrates the best performance among all the formats when the accumulated amplified spontaneous emission power （AASEP） is small. But with the increasing of AASEP, the superiority of RZ-DPSK transmission performance over the other five modulation formats is vanished. AASEP is justified to be the major source for the deterioration of the superiority.

关键词： Modulation Performance phase shift keying Signal encoding

Blind equalization and automatic modulation classification based on subspace for subcarrier MPSK optical communications

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Optoelectronics Letters 2017年第4期13卷 304-308页

作者： CHEN Dan GUO Lin-yuan WANG Chen-hao KE Xi-zheng School of Automation ＆ Information Xi ＇an University of Technology Xi＇an 710048 China Xi ＇an Polytechnic University Xi ＇an 710048 China

Equalization can compensate channel distortion caused by channel multipath effects, and effectively improve convergent of modulation constellation diagram in optical wireless system. In this paper, the subspace blind equalization algorithm is used to preprocess M-ary phase shift keying(MPSK) subcarrier modulation signal in receiver. Mountain clustering is adopted to get the clustering centers of MPSK modulation constellation diagram, and the modulation order is automatically identified through the k-nearest neighbor(KNN) classifier. The experiment has been done under four different weather conditions. Experimental results show that the convergent of constellation diagram is improved effectively after using the subspace blind equalization algorithm, which means that the accuracy of modulation recognition is increased. The correct recognition rate of 16 PSK can be up to 85% in any kind of weather condition which is mentioned in paper. Meanwhile, the correct recognition rate is the highest in cloudy and the lowest in heavy rain condition.

关键词： Blind equalization Meteorology Nearest neighbor search Optical communication Optical signal processing Optical systems phase shift keying Signal receivers

Influence of the nonlinear phase and ASE noise on DPSK balanced optical receiver in optical fiber communication system

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Optoelectronics Letters 2009年第1期5卷 45-47页

作者：李蔚梅君瑶韩庆生王腾 Wuhan National Lab for Optoelectronics Huazhong University of Science and Technology

The analytical expression of bit error probability in a balanced differential phase-shift keying(DPSK) optical receiver considering nonlinear phase noise and EDFA ASE noise is given,which is very useful to estimate the performance of DPSK balanced and unbalanced receiver in optical communication *** analysis,if only nonlinear phase noise is considered,both the balance and unbalanced receivers have the same *** if adding the ASE noise of EDFA,the balanced receiver is better.

关键词： Acoustic receivers Bit error rate Communication systems Optical fibers Optical receivers phase noise phase shift keying Probability

Non-linear polarization orthogonality loss in a semiconductor optical amplifier

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Chinese Optics Letters 2016年第9期14卷 6-9页

作者：章威李政勇王海洋詹翔空宋中波吴重庆 Key Laboratory of Education Ministry on Luminescence and Optical Information Technology Beijing Jiaotong University Institute of Optical Information School of ScienceBeijing Jiaotong University

Polarization-based optical communications are attracting more attention recently, where the crucial points are polarization features and their measurements. Based on the Müller matrix method, we obtain measurable expressions for the polarization-dependent gain（PDG） and the loss of polarization orthogonality（LPO）, while give the boundary of the LPO for any PDG devices. We experimentally demonstrate that non-linear LPO can be created in a semiconductor optical amplifier and find that the LPO will slightly skim over the boundary near the threshold of the injected current. Furthermore, an empirical formula is achieved to gauge the LPO-induced power penalty, which is proven to be valid in differential polarization shift-keying transmission by executing a bit error rate measurement. Our conclusions are applicable to non-orthogonal polarization cases and valuable to polarization-related communications, even orbital angular momentum multiplexing.

关键词： Bit error rate Light amplifiers Optical communication Optical switches phase shift keying Polarization Semiconductor insulator boundaries