scholarly journals Chromatic Dispersion Equalization FIR Digital Filter for Coherent Receiver

Photonics ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 478
Author(s):  
Zicheng Wu ◽  
Sida Li ◽  
Zhiping Huang ◽  
Fangqi Shen ◽  
Yongjie Zhao
Keyword(s):  
Frequency Band ◽  
Communication Systems ◽  
Pulse Shaping ◽  
Chromatic Dispersion ◽  
Digital Signal ◽  
Least Square ◽  
Effective Bandwidth ◽  
Adaptive Mutation ◽  
Particle Swarm Optimizer ◽  
Modulation Formats

Chromatic dispersion equalization (CDE) in coherent optical communication systems is extremely critical for subsequent digital signal processing (such as frequency offset estimation and carrier phase recovery). Various methods mentioned in the published literature are not satisfactory when the signal bandwidth is limited. This paper proposes a way of using singular value decomposition least square (SVDLS) to obtain the optimal tap weight of the CDE filter and a method to introduce the adaptive mutation particle swarm optimizer (AMPSO) algorithm into the CDE. We show that the two proposed approaches are based on the best approximation of the frequency domain response of the designed and ideal CDE filter. Compared with the traditional CDE method, which needs to be implemented in the full frequency band, the two methods can be implemented in the narrow frequency band. The simulation shows that the effective bandwidth of the baseband signal is limited by squared-root-raised-cosine (SRRC) pulse shaping with a roll-off factor of 0.25 in different modulation formats (DP-QPSK, DP-16 QAM, DP-64 QAM) when the number of taps of the filter is 131, which is 37.5% less than the full frequency band. The designed filter is superior to the existing filter in terms of filtering effect and implementation complexity.

Optical OFDM for Downstream Transmission in Long-Reach PON

2014 ◽  
Vol 631-632 ◽  
pp. 860-863 ◽  
Author(s):  
Xiao Xue Gong ◽  
Hui Li ◽  
Peng Chao Han ◽  
Yu Fang Zhou
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Direct Detection ◽  
Dispersion Compensation ◽  
Chromatic Dispersion ◽  
Optical Network ◽  
Digital Signal ◽  
Least Square ◽  
Passive Optical Network ◽  
Spectrum Efficiency ◽  
Flexible Resource

Orthogonal Frequency Division Multiplexing (OFDM) has gained great attention in the next generation Long-Reach Passive Optical Network (LR-PON) due to its high spectrum efficiency, flexible resource allocation and natural compatibility with Digital Signal Processing (DSP)-based implementation. In this paper, we propose and demonstrate a 40Gbit/s direct-detection long reach OFDM-PON system for downstream transmission over 100km standard signal mode fiber (SSMF). By using a simple Least Square (LS) method for the channel estimation, our proposed system achieves high bit rate without the need for chromatic dispersion compensation.

Experimental evaluation of pulse shaping based 5G multicarrier modulation formats in visible light communication systems

2020 ◽  
Vol 457 ◽  
pp. 124693 ◽  
Author(s):  
Felipe T. Monteiro ◽  
Wesley S. Costa ◽  
José L.C. Neves ◽  
David M.I. Silva ◽  
Helder R.O. Rocha ◽  
...  
Keyword(s):  
Visible Light ◽  
Experimental Evaluation ◽  
Communication Systems ◽  
Pulse Shaping ◽  
Visible Light Communication ◽  
Multicarrier Modulation ◽  
Modulation Formats

scholarly journals Efficient Modulation Formats for High Bit-Rate Fiber Transmission

2006 ◽  
Vol 16 (2) ◽  
pp. 17-26 ◽  
Author(s):  
A. García-Pérez ◽  
J. A. Andrade-Lucio ◽  
O. G. Ibarra-Manzano ◽  
E. Alvarado-Méndez ◽  
M. Trejo-Duran ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Communication Systems ◽  
Chromatic Dispersion ◽  
Polarization Mode Dispersion ◽  
Nonlinear Effects ◽  
Bit Rate ◽  
Modulation Formats ◽  
Modulation Format ◽  
Mode Dispersion ◽  
Advanced Modulation Formats

The topic of this report will deal with the study of advanced modulation formats for highspeed optical communication systems. Basically, the use of alternate polarization modulation (alP) is considered in order to reduce the inter-symbol interference (ISI) caused mainly by effects such as Chromatic Dispersion (CD), Polarization Mode Dispersion (PMD) and Nonlinear effects. The comparative analysis among the different formats is carried out by means of the obtaining of its different spectrums. A detailed analysis of these and their dependency to the modulation format that generates it is presented. The article presents numerical comparative analysis using commercial software VPI Maker Transmission, where the results obtained show that the formats of alternating polarization are the best results at the bit rate of 40 Gb/s per channel.

scholarly journals Design of a Microwave Power Detection System in the 5G-Communication Frequency Band

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2674
Author(s):  
Qingying Ren ◽  
Wen Zuo ◽  
Jie Xu ◽  
Leisheng Jin ◽  
Wei Li ◽  
...  
Keyword(s):  
Frequency Band ◽  
Microwave Power ◽  
Communication Systems ◽  
Detection System ◽  
Measurement Sensitivity ◽  
Detection Range ◽  
Detection Systems ◽  
Detection Frequency ◽  
Communication Frequency ◽  
5G Communication

At present, the proposed microwave power detection systems cannot provide a high dynamic detection range and measurement sensitivity at the same time. Additionally, the frequency band of these detection systems cannot cover the 5G-communication frequency band. In this work, a novel microwave power detection system is proposed to measure the power of the 5G-communication frequency band. The detection system is composed of a signal receiving module, a power detection module and a data processing module. Experiments show that the detection frequency band of this system ranges from 1.4 GHz to 5.3 GHz, the dynamic measurement range is 70 dB, the minimum detection power is −68 dBm, and the sensitivity is 22.3 mV/dBm. Compared with other detection systems, the performance of this detection system in the 5G-communication frequency band is significantly improved. Therefore, this microwave power detection system has certain reference significance and application value in the microwave signal detection of 5G communication systems.

Novel Manchester-Based Multilevel Signaling for High-Speed Optical Communication Systems

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Festus Idowu Oluwajobi ◽  
Nguyen Dong-Nhat ◽  
Amin Malekmohammadi
Keyword(s):  
Communication Systems ◽  
High Speed ◽  
Chromatic Dispersion ◽  
Optical Fiber Communication ◽  
Pulse Amplitude ◽  
Calculation Model ◽  
Fiber Communication ◽  
Receiver Sensitivity ◽  
Communication Links ◽  
Dispersion Tolerance

AbstractIn this paper, the performance of a novel multilevel signaling based on Manchester code namely four-level Manchester Coding (4-MC) technique is investigated for next generation high-speed optical fiber communication links. The performance of 4-MC is studied and compared with conventional Manchester modulation and four-level pulse amplitude modulation (4-PAM) formats in terms of receiver sensitivity, spectral efficiency and dispersion tolerance at the bit rate of 40 Gb/s. The bit error rate (BER) calculation model for the proposed multilevel scheme has also been developed. The calculated receiver sensitivity and the chromatic dispersion tolerance at the BER of 10–9 of the proposed scheme are −22 dBm and 67.5 ps/nm, respectively. It is observed that, 4-MC scheme is superior in comparison to 4-PAM by 3.5 dB in terms of receiver sensitivity in back-to-back scenario. Therefore, the proposed scheme can be considered as an alternative to current 4-PAM system.

scholarly journals EVM Loss: A Loss Function for Training Neural Networks in Communication Systems

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1094
Author(s):  
Scott Stainton ◽  
Martin Johnston ◽  
Satnam Dlay ◽  
Paul Anthony Haigh
Keyword(s):  
Neural Networks ◽  
Loss Function ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Frequency Division Multiplexing ◽  
Efficiency Gain ◽  
Frequency Division ◽  
Error Vector Magnitude ◽  
Modulation Formats ◽  
Complex Approach

Neural networks and their application in communication systems are receiving growing attention from both academia and industry. The authors note that there is a disconnect between the typical objective functions of these neural networks with regards to the context in which the neural network will eventually be deployed and evaluated. To this end, a new loss function is proposed and shown to increase the performance of neural networks when implemented in a communication system compared to previous methods. It is further shown that a ‘split complex’ approach used by many implementations can be improved via formalisation of the ‘concatenated complex’ approach described herein. Experimental results using the orthogonal frequency division multiplexing (OFDM) and spectrally efficient frequency division multiplexing (SEFDM) modulation formats with varying bandwidth compression factors over a wireless visible light communication (VLC) link validate the efficacy of the proposed method in a real system, achieving the lowest error vector magnitude (EVM), and thus bit error rate (BER), across all experiments, with a 5 dB to 10 dB improvement in the received symbols EVM overall compared to the baseline implementation, with bandwidth compressions down to 40% compared to OFDM, resulting in a spectral efficiency gain of 67%.

scholarly journals Reversible logic in pipelined low power vedic multiplier

2019 ◽  
Vol 16 (3) ◽  
pp. 1265
Author(s):  
Ansiya Eshack ◽  
S. Krishnakumar
Keyword(s):  
Low Power ◽  
Communication Systems ◽  
Large Scale ◽  
Optical Computing ◽  
Digital Signal ◽  
Logic Gates ◽  
Reversible Logic ◽  
Large Scale Integration ◽  
Time Required ◽  
Scale Integration

<span>With an ever growing demand for low-power devices, it is a general trend to search for ways to reduce the power consumption of a system. Multipliers are an important requirement in applications linked to Digital Signal Processing, Communication Systems, Optical Computing, Nanotechnology, Low-Power Very Large Scale Integration and Quantum Computing. Conventional mathematics makes multiplication a very long and time consuming process. The use of Vedic mathematics has led to great reduction in the time required for such calculations. The excessive use of Urdhava Tiryakbhyam sutra in multiplication surely proves its effectiveness and simplicity in this domain. This sutra supports the process of pipelining, a method employed in reduction of the power used by a system. Reversible logic has been gaining demand due to its low-power capabilities and is currently being used in many computing applications. The paper proposes two multiplier systems: one design employs the Urdhava Tiryakbhyam sutra along with pipelining and the second uses reversible logic gates into the first design. These proposed systems provide very less delay for result computation and low hardware utilization when compared to non-pipelined Vedic multipliers.</span>

Light fidelity optical network a comparative performance evaluation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Devendra Kr. Tripathi ◽  
Pallavi Singh
Keyword(s):  
Communication Systems ◽  
Optical Network ◽  
Visible Light Communication ◽  
Data Rate ◽  
Comparative Performance ◽  
Modulation Formats ◽  
High Data ◽  
Modulation Format ◽  
Output Performance ◽  
High Spectral Efficiency

Abstract Light-Fidelity (Li-Fi) is the bidirectional communication technique, tenders almost unlimited bandwidth, exploit unlicensed spectrum of light waves. Accordingly, this manuscript illustrates usage of visible light communication (VLC) applied as Li-Fi, an efficient scheme to broadcast data wirelessly as well safer technique in contrary to the customary Wireless-Fidelity (Wi-Fi) networks. In support numerical simulations have been executed over the proposed Li-Fi model for the parametric variation with the data rate, laser power, modulation format and wavelength, communication length. Investigations have showed good output performance, with hike in data rate BER variation as 10−94–10−23 and testing length. Simulations of network with DPSK and NRZ modulation formats at high data transmission of 10 Gbps have showed good output performance with 10−40 with DPSK format. Li-Fi systems are quality solution for the impending communication systems save cost, provide high spectral efficiency.

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