40 Gb/s High-speed mode-division multiplexing transmission employing NRZ modulation format

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Rabiu Imam Sabitu ◽  
Nafizah Goriman Khan ◽  
Amin Malekmohammadi
Keyword(s):  
System Performance ◽  
High Speed ◽  
Direct Detection ◽  
Signal To Noise Ratio ◽  
Optical Signal ◽  
Threshold Power ◽  
Modulation Format ◽  
Transmission Distance ◽  
Mode Division Multiplexing ◽  
Speed Mode

AbstractThis report examines the performance of a high-speed MDM transmission system supporting four nondegenerate spatial modes at 10 Gb/s. The analysis adopts the NRZ modulation format to evaluate the system performance in terms of a minimum power required (PN) and the nonlinear threshold power (PTH) at a BER of 10−9. The receiver sensitivity, optical signal-to-noise ratio, and the maximum transmission distance were investigated using the direct detection by employing a multimode erbium-doped amplifier (MM-EDFA). It was found that by properly optimizing the MM-EDFA, the system performance can significantly be improved.

scholarly journals Performance Analysis of Post Compensated Long Haul High Speed Coherent Optical OFDM System

2017 ◽  
Vol 7 (1) ◽  
pp. 160
Author(s):  
Divya Dhawan ◽  
Neena Gupta
Keyword(s):  
Performance Analysis ◽  
High Speed ◽  
Signal To Noise Ratio ◽  
Symbol Error Rate ◽  
Optical Signal ◽  
Mapping Method ◽  
Coherent Detection ◽  
Error Vector Magnitude ◽  
Modulation Formats ◽  
Transmission Distance

<p>This paper addresses the performance analysis of OFDM transmission system based on coherent detection over high speed long haul optical links with high spectral efficiency modulation formats such as Quadrature Amplitude Modulation (QAM) as a mapping method prior to the OFDM multicarrier representation. Post compensation is used to compensate for phase noise effects. Coherent detection for signal transmitted at bit rate of 40 Gbps is successfully achieved up to distance of 3200km. Performance is analyzed in terms of Symbol Error Rate and Error Vector Magnitude by varying Optical Signal to Noise Ratio (OSNR) and varying the length of the fiber i.e transmission distance. Transmission performance is also observed through constellation diagrams at different transmission distances and different OSNRs.</p>

scholarly journals Signal Intensity Estimation in Transdermal Optical Wireless Links with Stochastic Pointing Errors Effect

Technologies ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 60
Author(s):  
George K. Varotsos ◽  
Hector E. Nistazakis ◽  
Konstantinos Aidinis ◽  
Fadi Jaber ◽  
K. K. Mujeeb Rahman
Keyword(s):  
Signal Intensity ◽  
High Speed ◽  
Direct Detection ◽  
Minimum Mean Square Error ◽  
Path Loss ◽  
Optical Signal ◽  
Photon Absorption ◽  
Optical Wireless ◽  
Detection Scheme ◽  
Pointing Errors

Transdermal optical wireless (TOW) communication links have recently gained particular research and commercial attention as a viable alternative for establishing high speed and effective implantable data transmissions, which is vital for a variety of neuroprosthetic and other medical applications. However, the development of this optical telemetry modality with medical implanted devices (IMDs) is adversely affected by skin-induced photon absorption, scattering and pointing errors effects. Thus, in this work a minimum mean-square error (MMSE) criterion is proposed for the estimation of the optical signal intensity in a typical TOW link of varying path loss and misalignment-induced fading characteristics. In this context, the stochastic nature of the transmitter–receiver misalignment has been considered and jointly modeled with transdermal path loss. Additionally, the link is assumed to employ the suitable On–Off Keying (OOK) with intensity modulation and direct detection scheme as well as a PIN photodiode at the receiver side for signal detection. Under these assumptions the results demonstrate that the stochastic amount of pointing mismatch strongly affects the received irradiance estimation.

Efficient Blind Adaptive CSE to Reduce Cyclic Prefix Length in Direct Detection Optical OFDM Systems

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Asmaa Benieddi ◽  
Sid Ahmed Elahmar
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Direct Detection ◽  
Group Velocity Dispersion ◽  
Signal To Noise Ratio ◽  
Single Mode ◽  
Optical Signal ◽  
Single Mode Fiber ◽  
Cyclic Prefix ◽  
Ofdm Systems ◽  
Blind Adaptive

AbstractDirect detection optical orthogonal frequency division multiplexing (DDO-OFDM) systems for a long-reach of standard single mode fiber (SSMF) require a large length of cyclic prefix (CP) to avoid the inter-symbol interference (ISI) effect caused by group velocity dispersion (GVD). Unfortunately, this method is inefficient due to the energy wasted in CP samples. In order to reduce the CP length and to mitigate the residual ISI, a novel blind adaptive channel shortening equalizer (CSE) is proposed in this paper. Based on the orthogonality between subcarriers in the fast Fourier transform (FFT) property, the proposed algorithm attempts to minimize the sum-squared correlation (SSCM) between each sample located in a well-defined window to update the CSE coefficients. Thus, the combined channel-CSE response is shortened. Therefore, it can cancel the residual ISI effect due to the GVD and the short CP length. The performance of the system is evaluated on basis of bit error rate (BER) versus optical signal to noise ratio (OSNR) for different CP lengths. The simulation results validate the new algorithm SSCM and show that it can reduce the CP length with a much better system improvement than existing algorithms.

scholarly journals Optimization of system’s parameters for wavelength conversion of E-band signals

2022 ◽  
Vol 12 (2) ◽  
pp. 1659
Author(s):  
Yazan Alkhlefat ◽  
Sevia Mahdaliza Idrus Sutan Nameh ◽  
Farabi M. Iqbal
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Wavelength Conversion ◽  
Signal To Noise Ratio ◽  
Optical Amplifier ◽  
Optical Signal ◽  
Error Vector Magnitude ◽  
Wavelength Converter ◽  
High Data

Current and future wireless communication systems are designed to achieve the user’s demands such as high data rate and high speed with low latency and simultaneously to save bandwidth and spectrum. In 5G and 6G networks, a high speed of transmitting and switching is required for internet of things (IoT) applications with higher capacity. To achieve these requirements a semiconductor optical amplifier (SOA) is considered as a wavelength converter to transmit a signal with an orthogonal frequency division multiplexing with subcarrier power modulation (OFDM-SPM). It exploits the subcarrier’s power in conventional OFDM block in order to send additional bits beside the normally transmitted bits. In this paper, we optimized the SOA’s parameters to have efficient wavelength conversion process. These parameters are included the injection current (IC) of SOA, power of pump and probe signals. A 7 Gbps OFDM-SPM signal with a millimeter waves (MMW) carrier of 80 GHz is considered for signal switching. The simulation results investigated and analyzed the performance of the designed system in terms of error vector magnitude (EVM), bit error rate (BER) and optical signal-to-noise ratio (OSNR). The optimum value of IC is 0.6 A while probe power is 9.45 and 8.9 dBm for pump power. The simulation is executed by virtual photonic integrated (VPI) software.

scholarly journals Continuous-Variable Quantum Key Distribution Robust Against Polarization-Dependent Loss

2019 ◽  
Vol 9 (18) ◽  
pp. 3937
Author(s):  
Ying Guo ◽  
Minglu Cai ◽  
Duan Huang
Keyword(s):  
Quantum Key Distribution ◽  
Transmission Rate ◽  
Signal To Noise Ratio ◽  
Key Distribution ◽  
Continuous Variable ◽  
Optical Signal ◽  
Orthogonal Polarization ◽  
Secret Key ◽  
Polarization Dependent Loss ◽  
Transmission Distance

Polarization is one of the physical characteristics of optical waves, and the polarization-division-multiplexing (PDM) scheme has gained much attraction thanks to its capability of achieving high transmission rate. In the PDM-based quantum key distribution (QKD), the key information could be encoded independently by the optical fields E x and E y , where the 2-dimensional modulation and orthogonal polarization multiplexing usually result in two-fold channel capacity. Unfortunately, the non-negligible polarization-dependent loss (PDL) caused by the crystal dichroism in optical devices may result in the signal distortion, leading to an imbalanced optical signal-to-noise ratio. Here, we present a polarization-pairwise coding (PPC) scheme for the PDM-based continuous-variable (CV) QKD systems to overcome the PDL problem. Numerical simulation results indicate that the PDL-induced performance degradation can be mitigated. In addition, the PPC scheme, tailored to be robust against a high level of PDL, offers a suitable solution to improve the performance of the PDM-based CVQKD in terms of the secret key rate and maximal transmission distance.

Performance of a Direct-Detection Spot Mode Division Multiplexing in Multimode Fiber

2019 ◽  
Vol 40 (2) ◽  
pp. 161-166 ◽  
Author(s):  
Yousef Fazea ◽  
Mustafa Muwafak Alobaedy ◽  
Zeyid T. Ibraheem
Keyword(s):  
High Speed ◽  
Direct Detection ◽  
Cavity Surface ◽  
Multimode Fiber ◽  
Laser Array ◽  
Long Distance ◽  
Mode Division Multiplexing ◽  
Internet Users ◽  
Vertical Cavity Surface ◽  
Surface Emitting Laser

Abstract Multimode fiber (MMF) regarded as an excellent choice for providing large capacity and high-speed for applications such as data centers due to its adaptability and unwavering quality. The ceaseless development and the increase of Internet users that emphasis on increasing data capacity have promoted mode division multiplexing (MDM) as a promising contender for providing further level of multiplexing freedom by propagating several and dissimilar channels in different mode stream. This paper investigates and analyzes the effects of launching MDM spot mode with various vortex order using vertical-cavity surface-emitting laser array in conjunction with equalization scheme. A capacity of 40 Gbit/s transmitted over MMF long distance of 1500 m has been achieved at a wavelength of 1550.12 nm.

scholarly journals Optical Transmitters without Driver Amplifiers—Optimal Operation Conditions

2018 ◽  
Vol 8 (9) ◽  
pp. 1652 ◽  
Author(s):  
Arne Josten ◽  
Benedikt Baeuerle ◽  
Romain Bonjour ◽  
Wolfgang Heni ◽  
Juerg Leuthold
Keyword(s):  
Single Channel ◽  
Direct Detection ◽  
Signal To Noise Ratio ◽  
Optical Signal ◽  
Optimal Operation ◽  
Signal Quality ◽  
Root Mean Square Amplitude ◽  
Operation Conditions ◽  
Communication Links ◽  
Eye Opening

An important challenge in optical communications is the generation of highest-quality waveforms with a Mach–Zehnder modulator with a limited electrical swing (Vpp). For this, we discuss, under limited Vpp, the influence of the waveform design on the root-mean-square amplitude, and thus, the optical signal quality. We discuss the influence of the pulse shape, clipping, and digital pre-distortion on the signal quality after the electrical-to-optical conversion. Our simulations and experiments, e.g., suggest that pre-distortion comes at the expense of electrical swing of the eye-opening and results in a lower optical signal-to-noise ratio (OSNR). Conversely, digital post-distortion provides operation with larger eye-openings, and therefore, provides an SNR increase of at least 0.5 dB. Furthermore, we find that increasing the roll-off factor increases the electrical swing of the eye-opening. However, there is negligible benefit of increasing the roll-off factor of square-root-raised-cosine pulse shaped signals beyond 0.4. The findings are of interest for single-channel intensity modulation and direct detection (IM/DD) links, as well as optical coherent communication links.

CO-OFDM System with 16-QAM Subcarrier Modulation Using Reconfigurable Optical Add Drop Multiplexer

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Aruna Rani ◽  
Manjit Singh Bhamrah ◽  
Sanjeev Dewra
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Optical Switch ◽  
Signal To Noise Ratio ◽  
Optical Power ◽  
Optical Signal ◽  
Signal Power ◽  
Frequency Division ◽  
Link Length ◽  
Transmission Distance ◽  
Fiber Link

AbstractIn this paper, sixteen 50 GHz spaced orthogonal frequency division multiplexing channels at 10 Gbps has been investigated with reconfigurable optical add drop multiplexer based on digital optical switch. The effects of fiber link length and input optical signal power on bit error rate, quality factor, output signal power, optical signal to noise ratio at the receiving side are observed. It is observed that maximal transmission distance of 2,100 km is achieved with an input optical power of −8 dBm.

scholarly journals Turbo-coded Ultra Long Haul System with Probabilistic Shaped 16QAM Modulation

2021 ◽  
Vol 2112 (1) ◽  
pp. 012027
Author(s):  
Ziqi Wang ◽  
Yuzhe Li ◽  
Yuan Gao ◽  
Xishuo Wang ◽  
Qi Zhang
Keyword(s):  
Communication Technology ◽  
Mobile Communication ◽  
High Speed ◽  
Turbo Code ◽  
Optical Fiber Communication ◽  
Modulation Scheme ◽  
Modulation Format ◽  
Transmission Distance ◽  
Bit Error Ratio ◽  
Mobile Communication Technology

Abstract With the rapid growth and development of 5G (5th Generation Mobile Communication Technology) and the incoming of 6G (6th Generation Mobile Communication Technology), the demand for high-speed and flexible communication solutions is becoming far more urgent. Within this paper, a novel code modulation scheme based on PS (probabilistic shaping) and Turbo code is proposed with its effectiveness is confirmed by the results of simulation. The results inform that in an optical fiber communication system with 56 Gb/s rate and 3000 km transmission distance, when the SNR (signal-noise ratio) is greater than 3.5 dB, the Turbo-coded PS-16QAM modulation format can achieve reliable transmission. The proposed scheme performs the best in BER (bit error ratio) and average launch power in the four cases of uniform 16QAM, PS-16QAM, Turbo-coded 16QAM with and itself. The proposed scheme is a potential solution in the future 5G communication.

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