scholarly journals Investigation of Coded WOFDM System over Multimode Optical Channels

2020 ◽  
pp. 619-625
Author(s):  
Farhad Sadeghi Almaloo ◽  
◽  
Majid Zarie ◽  
Mahdi Akbari Allah Abadi ◽  
Ghader Mohammadi Aghdash
Keyword(s):  
Performance Improvement ◽  
Communication System ◽  
Orthogonal Frequency Division Multiplexing ◽  
Wavelet Packet ◽  
Optical Channel ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Ofdm System ◽  
Modulation Format ◽  
Simulation Results

In this paper, the performance of Asymmetrically Clipped Optical Wavelet based Orthogonal Frequency Division Multiplexing (ACO WOFDM) system is compared to the performance of Asymmetrically Clipped Optical Orthogonal Frequency Division Multiplexing (ACO OFDM) system. Then a Coded ACO WOFDM (CACO WOFDM) communication system over a multimode optical channel is investigated. The used wavelet transform is the Wavelet Packet Transform (WPT). Quadrature Amplitude Modulation (QAM) is used as the modulation format. The simulation results show a considerable performance improvement of ACO WOFDM system in terms of BER and slight performance improvement of ACO WOFDM system in terms of OSNR Compared to the ACO OFDM system. Also, from the simulation results, we find that the CACO WOFDM considerably improves the BER and OSNR performance of the communication system.

Study and Simulation Analysis of OFDM System Based on Simulink

2013 ◽  
Vol 706-708 ◽  
pp. 1967-1970
Author(s):  
Tong Qiang Li ◽  
Li Gang Xu
Keyword(s):  
Simulation Model ◽  
Communication System ◽  
Orthogonal Frequency Division Multiplexing ◽  
Simulation Analysis ◽  
Performance Characteristics ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Ofdm System ◽  
The Future ◽  
Simulation Results

Orthogonal Frequency Division Multiplexing(OFDM) is going to become the most important technique in the future communication system. The paper presents the principle of OFDM,establishes a simulation model of OFDM communication system based on simulink.By utilizing the system,we briefly analyse the simulation results and conclude the the performance characteristics of OFDM system.

scholarly journals A CCM-Based OFDM System with Low PAPR for Sparse Source

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Qinbiao Yang ◽  
Zulin Wang ◽  
Qin Huang
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Coded Modulation ◽  
High Peak ◽  
Frequency Division Multiplexing ◽  
Power Ratio ◽  
Frequency Division ◽  
Ofdm System ◽  
Simulation Results ◽  
Clipping And Filtering

Orthogonal frequency division multiplexing (OFDM) usually suffers high peak-to-average power ratio (PAPR). As shown in this paper, PAPR becomes even severe for sparse source due to many identical nonzero frequency OFDM symbols. Thus, this paper introduces compressive coded modulation (CCM) in order to restrain PAPR by reducing identical nonzero frequency symbols for sparse source. As a result, the proposed CCM-based OFDM system, together with iterative clipping and filtering, can efficiently restrain the high PAPR for sparse source. Simulation results show that it outperforms about 4 dB over the traditional OFDM system when source sparsity is 0.1.

The Study of Interpolation Algorithms in OFDM Systems

2013 ◽  
Vol 321-324 ◽  
pp. 2837-2840
Author(s):  
Xi Jun Zhang ◽  
Jian Bin Xue ◽  
Ying Lin ◽  
Ji Ai He
Keyword(s):  
Channel Estimation ◽  
Orthogonal Frequency Division Multiplexing ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Ofdm Systems ◽  
Ofdm System ◽  
Simulation Process ◽  
Interpolation Algorithms ◽  
Simulation Results

Orthogonal frequency division multiplexing (OFDM) is a kind of highly transmission technology. It has been taken more and more attention in many ways. In this paper it mainly discussed the simulation process and several interpolation algorithms in OFDM system. Using computer we simulate the interpolation algorithms in OFDM channel estimation. Through the simulation results we compare the advantage and disadvantage of the interpolation algorithms. At last we can use the conclusion to choose the correct interpolation algorithms in OFDM channel estimation.

scholarly journals Design and implementation of low power encoder incorporating adaptive modulation for multi user OFDM system

2018 ◽  
Vol 7 (1.9) ◽  
pp. 41
Author(s):  
K Jayaram ◽  
Dr C.Arun
Keyword(s):  
Wireless Communication ◽  
Low Power ◽  
Communication System ◽  
Orthogonal Frequency Division Multiplexing ◽  
Adaptive Modulation ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Ofdm System ◽  
Wireless Communication System ◽  
Design And Implementation

Wireless communication system is a key element in modern uninterupted data tramsnission and reception services. In this paper, multi user Orthogonal Frequency Division Multiplexing (OFDM) system is designed with low power encoder and adaptive modualtion architectures. The proposed multi user encoder architecture is designed in Verlog HDL and simulated in Modelsim simulator. Xilinx Project Navigator is used to evaluate the performance of the proposed architecture interms of power consumptions and hardware utilizations by implementing the architecture on different virtex processors.

scholarly journals Deep neural network for orthogonal frequency division multiplexing systems without cyclic prefix transmission

2018 ◽  
Vol 189 ◽  
pp. 04016
Author(s):  
Viet-Hung Nguyen ◽  
Minh-Tuan Nguyen ◽  
Yong-Hwa Kim
Keyword(s):  
Neural Network ◽  
Orthogonal Frequency Division Multiplexing ◽  
Deep Neural Network ◽  
Cyclic Prefix ◽  
Wireless Transmission ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Ofdm System ◽  
New Approach ◽  
Multiplexing Systems

Orthogonal frequency division multiplexing (OFDM) is widely used in wired or wireless transmission systems. In the structure of OFDM, a cycle prefix (CP) has been exploited to avoid the effects of inter-symbol interference (ISI) and inter-carrier interference (ICI). This paper proposes a new approach to transmit the signals without CP transmission. Using the deep neural network, the proposed OFDM system transmits data without the CP. Simulation results show that the proposed scheme can estimate the CP at the receiver and overcome the effect of ISI.

scholarly journals Channel estimation of OFDM in C-band communication systems under different distribution conditions

2021 ◽  
Vol 23 (3) ◽  
pp. 1778
Author(s):  
Heba Abdul-Jaleel Al-Asady ◽  
Hassan Falah Fakhruldeen ◽  
Mustafa Qahtan Alsudani
Keyword(s):  
Fourier Transform ◽  
Channel Estimation ◽  
Fast Fourier Transform ◽  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Ofdm System ◽  
High Data ◽  
High Efficient

<p>Orthogonal frequency division multiplexing (OFDM) is a transmission system that uses multiple orthogonal carriers that are sent out at the same time. OFDM is a technique for mobile and wireless communication that has high-efficient frequency utilization, high data-rate transmission, simple and efficient implementation using the fast Fourier transform (FFT) and the inverse fast Fourier transform (IFFT), and reduces inter symbol interference (ISI) by inserting cyclic prefix (CP). One of the most important approaches in an OFDM system is channel estimation. In this paper, the orthogonal frequency division multiplexing system with the Rayleigh channel module is analyzed for different areas. The proposed approach used large numbers of subcarriers to transmit the signals over 64-QAM modulation with pilot add channel estimation. The accuracy of the OFDM system is shown in the measuring of the relationships of peak power to the noise ratio and bit error rate.</p>

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