- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Ordered Sequence Detection and Barrier Signal Design for Digital Pulse Interval Modulation in Optical Wireless Communications
摘要： This paper proposes an ordered sequence detection (OSD) for digital pulse interval modulation (DPIM) in optical wireless communications. Leveraging the sparsity of DPIM sequences, OSD shows comparable performance to the optimal maximum likelihood sequence detection (MLSD) with much lower complexity. Compared with the widely adopted sample-by-sample optimal threshold detection (OTD), it considerably improves the bit error rate (BER) performance by mitigating error propagation. Moreover, this paper proposes a barrier signal-aided digital pulse interval modulation (BDPIM), where the last of every K symbols is allocated with more power as an inserted barrier signal. BDPIM with OSD (BDPIM-OSD) can limit the error propagation between two adjacent barriers. To reduce the storing delay when using OSD to detect extremely large packets, we propose BDPIM with a combination of OTD and OSD (BDPIM-OTD-OSD), within which long sequences are cut into pieces and separately detected. Approximate upper bounds of the average BER performance of DPIM-OTD, DPIM-OSD, BDPIM-OSD and BDPIM-OTD-OSD are analyzed. Simulations are conducted to corroborate our analysis. Optimal parameter settings are also investigated in uncoded and coded systems by simulations. Simulation results show that the proposed OSD and BDPIM bring significant improvement in uncoded and coded systems over various channels.
关键词： signal design,error propagation,bit error rate,ordered sequence detection,Digital pulse interval modulation
更新于2025-09-23 15:23:52
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10?Gbps CPRI signals transmission impaired by intercore crosstalk in 5G network fronthauls with multicore fibers
摘要： The impact of intercore crosstalk (ICXT) of weakly-coupled multicore fibers (MCFs) on the transmission performance of a Common Public Radio Interface (CPRI) signal in 5G networks fronthaul is studied by numerical simulation. The results show that forward error correction-supported CPRI signals have more tolerance to ICXT due to the higher targeted bit error rate (of 10?3). For a receiver power penalty of 1 dB, an improvement of the tolerance of CPRI signals to ICXT, due to the increase of the MCF skew by about 1 dB, is observed. However, for the crosstalk levels that lead to 1 dB power penalty, we have shown that, the system is unavailable with a high probability. The crosstalk level required for an acceptable outage probability is about 10 dB lower than the crosstalk level leading to 1 dB power penalty.
关键词： 5G wireless networks,Multicore fiber,Common public radio interface,Outage probability,Intercore crosstalk,Bit error rate
更新于2025-09-23 15:23:52
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Error performance of optical wireless communication systems exercising BPSK subcarrier intensity modulation in non-Kolmogorov turbulent atmosphere
摘要： Subcarrier intensity modulation (SIM) scheme is preferred due to efficient bandwidth usage superiority over other modulation techniques such as on–off keying (OOK), pulse position modulation (PPM). In this paper, we investigate the bit error rate (BER) performance of optical wireless communication (OWC) system using binary phase shift keying (BPSK) SIM in non-Kolmogorov turbulent atmosphere. We pay attention to the weak turbulence conditions by using Rytov approximation and considering that the receiver is a PIN photodetector. Propagating beam type is Gaussian. It is seen that BER performance of the BPSK SIM OWC is significantly affected from non-Kolmogorov power law exponent, load resistor, responsivity of the PIN photodetector, bandwidth, beam source size, turbulence strength and noise factor.
关键词： Subcarrier intensity modulation,Optical wireless communication,Bit error rate,Atmospheric turbulence
更新于2025-09-23 15:23:52
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[IEEE 2018 International Conference on Advanced Science and Engineering (ICOASE) - Duhok (2018.10.9-2018.10.11)] 2018 International Conference on Advanced Science and Engineering (ICOASE) - An ICI Reduction Based on PAPR Clipping in Coherent Optical OFDM System
摘要： The Inter-Carrier Interference (ICI) compensation for Coherent Optical Orthogonal Frequency Division Multiplexing (CO-OFDM) system has been studied in this paper. The purpose behind is to investigate the presence of ICI due to the impact of Laser Phase Noise (LPN) and Fiber Non-Linearity (FNL). Thereby, we propose a simple clipping scheme which represents an effective distortion algorithm to decrease the Peak to Average Power Ratio (PAPR) for 4QAM system. The method exhibits a significant process on ICI cancellation in CO-OFDM system. The OFDM signal is basically transmitted along 550km distance rated at 10Gbps single mode fiber for the coherent optical mode. The new findings show that the receiver sensitivity is highly improved below 10-3 FEC for laser power 5dBm; and archives about 1dBm to 2.4dBm when laser power becomes 8dBm at a typical clipping ratio of 0.6. In particular, the system exhibits a good performance over a 385km transmission distance in comparison to the conventional CO-OFDM. As a result, the proposed clipping shows that the system can enhance its the performance by reducing ICI in the CO-OFDM system; in addition to present a high robustness in BER metric against FNL by a clear reduction in PAPR.
关键词： Coherent Optical Orthogonal Frequency Division Multiplexing (CO-OFDM),Inter-Carrier Interference (ICI),Peak to Average Power Ratio (PAPR),Fiber Nonlinearity (FNL),Bit Error Rate (BER),Laser Phase Noise (LPN)
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Intelligent and Innovative Computing Applications (ICONIC) - Mon Tresor, Plaine Magnien, Mauritius (2018.12.6-2018.12.7)] 2018 International Conference on Intelligent and Innovative Computing Applications (ICONIC) - Climatic Effects on Free Space Optics Link: South African Climate
摘要： The growth in demand of high data rate, reliable quality of service, low cost technology and secured connectivity have been telecommunication users' concerns. Free Space Optics (FSO) is the best choice for meeting these demands as it offers data rates in Gbps with the most secure communication because light beam is prone to eavesdropping. However, usage of FSO as a communication link relies upon local weather condition. Atmospheric attenuation of fog, rain and snow are the most limitation of free space optic availability, as they lead to the diminution of limited available bandwidth. This paper investigated the link performance under climatic conditions such as fog, rain and snow by at various wavelengths of 650nm, 750nm, 850nm, 950nm and 1550nm. It is further deals with FSO performance targeting to acquire minimal Bit Error Rate (BER), suitable transmitting power, optimum link margin and reliable data transmission rate at maximum link distance of 1km. The studies observed that received power signal and the link distance have an inverse correlation because once the signal reaches to an extended distance; it faces greater climatic attenuation due to scattering and absorption lessening.
关键词： communication link,Free space optics,atmospheric attenuation,light beam,bit error rate
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET) - Chennai (2018.3.22-2018.3.24)] 2018 International Conference on Wireless Communications, Signal Processing and Networking (WiSPNET) - Performance Analysis for Mixed Line Rates (MLR) WDM/DWDM Networks Under Various Modulation Techniques
摘要： In recent years, a rapid growth of new technologies requires communication systems to support higher bit rate and longer distance. The Optical network is one of the best optimal solutions which can satisfy the demand for high data rate. The performance of current optical networks depends on the traffic demands. To minimize the traffic mixed line rate (MLR) optical network is implemented. In a transparent MLR optical network, data transmission is done over different wavelength at different line rates within the same fiber. MLR optical networks with data rate 10/40/100 Gb/s over different wavelength channels is a new networking paradigm. This paper considers various modulation techniques in order to achieve better bit error rates (BER). It also shows that modulation technique has a great role in improving the data rates and quality of transmission.
关键词： Wavelength division multiplexing/Dense wavelength division Multiplexing (WDM/DWDM),Bit error rate,Chromatic dispersion,Mixed line rates,Physical layer impairments,Amplifier spontaneous emission
更新于2025-09-23 15:22:29
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Error rate and ergodic capacity of RF-FSO system with partial relay selection in the presence of pointing errors
摘要： This paper presents an analysis of a multiple dual-hop relaying system, which is composed of km-class radio frequency (RF)-free-space optical (FSO) links. Partial relay selection based on outdated channel state information (CSI) is employed in order to select active relay for further transmission. Amplify-and-forward relaying protocol is utilized. The RF links are assumed to be subject to Rayleigh fading, and the FSO links are influenced by both Gamma-Gamma atmospheric turbulence and pointing errors. On the basis of our previously derived expression for cumulative distribution function of the equivalent signal-to-noise ratio of the whole system, we derive novel analytical expressions for the average bit-error rate (BER) and ergodic capacity that are presented in terms of the Meijer’s G-function and extended generalized bivariate Meijer’s G-function, respectively. The numerical results are confirmed by Monte Carlo simulations. Considering the effect of time-correlation between outdated CSI and actual CSI related to the RF channel at the time of transmission, the average BER and the ergodic capacity dependence on various system and channel parameters are observed and discussed. The results illustrate that the temporal correlation between outdated and actual CSI has strong effect on system performance, particularly on BER values, when FSO hop is influenced by favorable conditions.
关键词： ergodic capacity,free-space optical systems,Bit error rate,partial relay selection,radio frequency systems.
更新于2025-09-23 15:22:29
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[IEEE 2018 Second International Conference on Electronics, Communication and Aerospace Technology (ICECA) - Coimbatore (2018.3.29-2018.3.31)] 2018 Second International Conference on Electronics, Communication and Aerospace Technology (ICECA) - FSO Link Performance Analysis with Different Modulation Techniques under Atmospheric Turbulence
摘要： Free space optics (FSO) has achieved prominence in extremely large bandwidth, unlicensed spectrum and low power secure transmission in the field of wireless communication. Despite the advantages, it is deeply impacted due to atmospheric turbulence and fog weather conditions. This paper considers different modulation schemes under the presence of atmospheric turbulence and fog conditions. The desired expression of bit error rate (BER) is obtained by modeling the turbulence as gamma-gamma distributed channel and under this channel condition, 16-PPM has provided better performance than other schemes. BER is considered for the channel performance evaluation. This analysis can help to adopt a modulation technique according to the channel condition.
关键词： Bit error rate (BER),gamma-gamma distribution,atmospheric turbulence,Free space optics (FSO),Meijer’s G function
更新于2025-09-23 15:21:21
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Research on the Performance of 40 Gbps UV Communication System Based on DWDM
摘要： Due to the atmospheric transmission attenuation, the rate of UV communication is low and range is limited at present. According to the idea of DWDM in optical fiber communication, we proposed a 40 Gbps UV communication scheme, which has 8 channels in total. The transmission rate of each channel is 5 Gbps. And its performance was simulated by the optical communication system simulation design software which is called OptiSystem. Simulation analysis shows that the maximum transmission distance of the designed system is up to 1200 meters under the transmission rate of 40 Gbps without any compensation scheme. On the 280nm channel, the minimum error rate and Q factor are 1.56-14 and 7.59201 at 1 km respectively. When the transmission distance reaches 1.5 kilometers, the bit error rate becomes very high and the communication effect is very poor. The simulation results can provide reference for the design of UV communication system.
关键词： DWDM,OptiSystem,bit error rate,UV communication,Q factor
更新于2025-09-23 15:21:01
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[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Dual Polarization (TE and TM) Terahertz Spoof Surface Plasmon Polaritons Enabled by Metasurface
摘要： The FEC limit paradigm is the prevalent practice for designing optical communication systems to attain a certain bit error rate (BER) without forward error correction (FEC). This practice assumes that there is an FEC code that will reduce the BER after decoding to the desired level. In this paper, we challenge this practice and show that the concept of a channel-independent FEC limit is invalid for soft-decision bit-wise decoding. It is shown that for low code rates and high-order modulation formats, the use of the soft-decision FEC limit paradigm can underestimate the spectral efficiencies by up to 20%. A better predictor for the BER after decoding is the generalized mutual information, which is shown to give consistent post-FEC BER predictions across different channel conditions and modulation formats. Extensive optical full-field simulations and experiments are carried out in both the linear and nonlinear transmission regimes to confirm the theoretical analysis.
关键词： forward error correction,soft-decision decoding,generalized mutual information,Bit error rate,mutual information
更新于2025-09-23 15:19:57