scholarly journals Mitigation of Nonlinear Distortions for a 100 Gb/s Radio-Over-Fiber-Based WDM Network

Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1796 ◽  
Author(s):  
Saifur Rahman ◽  
Farman Ali ◽  
Adrian Smagor ◽  
Fazal Muhammad ◽  
Usman Habib ◽  
...  
Keyword(s):  
Fiber Optics ◽  
Mobile Networks ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Data Rate ◽  
Radio Over Fiber ◽  
Limiting Factors ◽  
Modulation Formats ◽  
Transmission Distance ◽  
Nonlinear Distortions

Next-generation cloud radio access networks (C-RANs) are anticipated to provide multi-Gbps data rate transmission and ultra-high bandwidth capacity, which is one of the key performance indicators for future mobile networks. The integral layout of fiber optics and radio network manages the capabilities of the C-RAN, but needs to be optimized in terms of cost, reliability and further scalibility. For C-RAN architectures, Radio over Fiber (RoF) transport-based fronthaul is a promising candidate but the associated issues of distortions due to nonlinear impairments (NLIs) from power amplifier, linear distortions (LDs) due to modulating lasers and high peak to average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals need to be addressed. This work investigates these performance limiting factors and presents a DSP receiver-based solution to mitigate the effects of NLIs, LDs and high PAPR. Simulations are performed by applying a various range of transmission input powers, different quadrature amplitude modulation (QAM) formats for the OFDM signal, optimized filtering at the receiver end and varying channel spacing among the optical WDM channels to analyze the performance of the proposed receiver under different conditions. The simulations and theoretical model of the proposed case studies verify that the presented solution for the RoF transport utilize less power, performs better for longer transmission distances, supports higher modulation formats and transports large number of WDM channels in the presence of NLIs and DLs as compared to the conventional RoF approach. With compensation of NLIs and LDs, transmission distance up to 10 km is investigated using 16 WDM channels with aggregate data rate of 100 Gb/s which shows that the proposed receiver can be used for future C-RAN fronthaul networks.

Performance Analysis of Digital Modulation for Coherent Detection of OFDM Scheme on Radio over Fiber System

2016 ◽  
Vol 6 (3) ◽  
pp. 1086 ◽  
Author(s):  
Fauza Khair ◽  
Fakhriy Hario P ◽  
I Wayan Mustika ◽  
Budi Setiyanto
Keyword(s):  
Error Rate ◽  
Orthogonal Frequency Division Multiplexing ◽  
Fiber Length ◽  
Direct Detection ◽  
Symbol Error Rate ◽  
Radio Over Fiber ◽  
Coherent Detection ◽  
Fiber System ◽  
Digital Modulation ◽  
Modulation Formats

Radio over fiber (RoF) system with the coherent detection offers high linearity for the transparent transport of high-frequency microwave signals, and better receiver sensitivity compared with intensity-modulated direct detection systems. The purpose of this paper is to analyze the performance of digital modulation for coherent detection of orthogonal frequency division multiplexing (OFDM) scheme on RoF system at 10 Gbps up to 100 km fiber length. The results show that coherent detection of OFDM-RoF system with 16 quadrature amplitude modulation (16-QAM) has the value of  bit error rate (BER) and the symbol error rate (SER) is very low and its constellation is better compared with other modulation formats (4-QAM, quadrature phase shift keying (QPSK), 8-PSK and 16-PSK), which BER 16-QAM is 0.053 and SER is 15.7%. The results also show that BER value of 4-QAM and QPSK relatively similar to fiber length variations. In general, an increasing value of the BER and SER for each modulation format are almost equal to the fiber length of 60-70 km (Region I and II). However, there is a significant increase in the value of BER in fiber length of 80-100 km (Region III. A and III. B) for the modulation of 4-QAM, QPSK, 8-PSK, and 16-PSK.

scholarly journals Performance Analysis of Digital Modulation for Coherent Detection of OFDM Scheme on Radio over Fiber System

2016 ◽  
Vol 6 (3) ◽  
pp. 1086
Author(s):  
Fauza Khair ◽  
Fakhriy Hario P ◽  
I Wayan Mustika ◽  
Budi Setiyanto
Keyword(s):  
Error Rate ◽  
Orthogonal Frequency Division Multiplexing ◽  
Fiber Length ◽  
Direct Detection ◽  
Symbol Error Rate ◽  
Radio Over Fiber ◽  
Coherent Detection ◽  
Fiber System ◽  
Digital Modulation ◽  
Modulation Formats

Radio over fiber (RoF) system with the coherent detection offers high linearity for the transparent transport of high-frequency microwave signals, and better receiver sensitivity compared with intensity-modulated direct detection systems. The purpose of this paper is to analyze the performance of digital modulation for coherent detection of orthogonal frequency division multiplexing (OFDM) scheme on RoF system at 10 Gbps up to 100 km fiber length. The results show that coherent detection of OFDM-RoF system with 16 quadrature amplitude modulation (16-QAM) has the value of  bit error rate (BER) and the symbol error rate (SER) is very low and its constellation is better compared with other modulation formats (4-QAM, quadrature phase shift keying (QPSK), 8-PSK and 16-PSK), which BER 16-QAM is 0.053 and SER is 15.7%. The results also show that BER value of 4-QAM and QPSK relatively similar to fiber length variations. In general, an increasing value of the BER and SER for each modulation format are almost equal to the fiber length of 60-70 km (Region I and II). However, there is a significant increase in the value of BER in fiber length of 80-100 km (Region III. A and III. B) for the modulation of 4-QAM, QPSK, 8-PSK, and 16-PSK.

scholarly journals New technique combining the Tone Reservation method with Clipping technique to reduce the Peak-to-Average Power Ratio

2018 ◽  
Vol 8 (6) ◽  
pp. 5215
Author(s):  
Hajar Abdelali
Keyword(s):  
Power Amplifier ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Papr Reduction ◽  
Power Ratio ◽  
Gain Compression ◽  
Nonlinear Distortions ◽  
Comparison Results ◽  
Tone Reservation ◽  
Linear Power Amplifier

Nonlinear distortions and impairments appear in multicarrier signal with high fluctuations when amplified by a Radio Frequency Power Amplifier (RF PA). Clipping (CL) technique offers a simple way to reduce these fluctuations in Orthogonal Frequency Division Multiplexing (OFDM) Technique, but may degrade seriously the transmission quality. This is why the new mobile standards propose other methods, like the Tone Reservation (TR) technique in the Digital Video Broadcasting-Terrestrial (DVB-T), that reduce the Peak-to-Average Power Ratio (PAPR) without reaching optimal performances. This paper deals with how we can use the TR technique, which exploits null sub-carriers for generating corrective signal, in combining to CL technique in order to improve PAPR reduction without data loss. Also, we show some comparison results on the PAPR reduction obtained with proposed scheme and other techniques. Experiments using a simulated example on a complete WiMax 802.16e transmitter have been made in order to investigate the PAPR reduction performances on presence of the non-linear Power Amplifier model based on gain compression response and phase distortion.

scholarly journals Integrating Radio-Over-Fiber Communication System and BOTDR Sensor System

Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2232 ◽  
Author(s):  
Wai Pang Ng ◽  
Nageswara Lalam ◽  
Xuewu Dai ◽  
Qiang Wu ◽  
Yong Qing Fu ◽  
...  
Keyword(s):  
Optical Fiber ◽  
Communication System ◽  
Orthogonal Frequency Division Multiplexing ◽  
Time Domain Reflectometry ◽  
Radio Over Fiber ◽  
Integrated System ◽  
Sensor System ◽  
Error Vector Magnitude ◽  
Modulation Formats ◽  
Fiber Link

In this paper, we propose and experimentally demonstrate for the first time, the integration of a radio-over-fiber (RoF) communication system and a Brillouin optical time-domain reflectometry (BOTDR) distributed sensor system using a single optical fiber link. In this proof-of-concept integrated system, the communication system is composed of three modulation formats of quadrature phase-shift keying (QPSK), 16-quadrature amplitude modulation (16-QAM) and 64-QAM, which are modulated onto an orthogonal frequency division multiplexing (OFDM) signal. Whereas, the BOTDR sensor system is used for strain and/or temperature monitoring over the fiber distance with a spatial resolution of 5 m using a 25 km single-mode silica fiber. The error vector magnitude (EVM) is analyzed in three modulation formats in the presence of various BOTDR input pump powers. Using QPSK modulation, optimized 18 dBm sensing and 10 dBm data power, the measured EVM values with and without bandpass filter are 3.5% and 14.5%, respectively. The proposed system demonstrates a low temperature measurement error (±0.49 °C at the end of 25 km) and acceptable EVM values, which were within the 3GPP requirements. The proposed integrated system can be effectively applied for practical applications, which significantly reduces the fiber infrastructure cost by effective usage of a single optical fiber link.

scholarly journals Performance investigation of long-haul high data rate optical OFDM IM/DD system with different QAM modulations

2021 ◽  
Vol 72 (3) ◽  
pp. 192-197
Author(s):  
Necmi Taspınar ◽  
Mahmoud Alhalabi
Keyword(s):  
Orthogonal Frequency Division Multiplexing ◽  
Direct Detection ◽  
Dispersion Compensation ◽  
Data Rate ◽  
High Data Rate ◽  
Ofdm System ◽  
Propagation Length ◽  
Eye Diagram ◽  
High Data ◽  
Transmission Distance

Abstract In this paper and as a first time, we have designed and simulated 100 Gbps long haul intensity modulation and direct detection (IM/DD) optical orthogonal frequency division multiplexing (OFDM) system with high order modulation techniques by using optisystem software QAM IM/DD OFDM system was analyzed and simulated to provide high data rate for downstream signal by using dispersion compensation fiber (DCF) inside fiber link. 4-QAM OFDM system demonstrated the best BER performance compared to other simulated systems for long haul transmission distance. For comparison and investigation, important results as eye diagram, Q factor, Eb/No and BER are explained against propagation length for every simulated system.

PAPR Reduction in OFDM Signal by Incorporating Mu-Law Companding Approach into Enhanced PTS Scheme

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Zeyid T. Ibraheem ◽  
Md. Mijanur Rahman ◽  
Yousef Fazea ◽  
Kawakib K. Ahmed
Keyword(s):  
Communication Systems ◽  
Orthogonal Frequency Division Multiplexing ◽  
Hybrid Approach ◽  
Average Power ◽  
High Capacity ◽  
Papr Reduction ◽  
Modulation Formats ◽  
Block Partitioning ◽  
Block Partition ◽  
Partition Method

AbstractOrthogonal Frequency Division Multiplexing (OFDM) is a potential transmission approach for high capacity communication systems. Despite the many advantages of OFDM, the major downside is the high peak-to-average power ratio (PAPR) which increases the system complexity, reduces the efficiency of the system, causes degradation in BER performance, and makes OFDM sensitive to nonlinear distortion in the transmission. Various methods have been proposed to deal with the PAPR problem, including the partial transmit sequence (PTS) that has attracted considerable attention. Hence, this paper presents a hybrid approach combining an enhanced PTS technique with Mu-Law companding. The PTS technique was enhanced through improving its sub-block partitioning scheme, where the enhanced partitioning scheme consolidated a conventional interleaved partitioning into an adjacent partitioning scheme. This incorporation of Mu-Law characteristic in time domain for PAPR reduction in OFDM essentially enhances the PAPR reduction performance, based on using numerical simulation results. Consequently, though the pseudorandom sub-block partition method obtains better PAPR reduction more than the other sub-block partition schemes (interleaved and adjacent) of ordinary PTS, it is quite difficult to be designed. The findings show that the enhanced PTS technique with Mu-Law companding, while maintaining low computational complexity, performs significantly better than the pseudorandom partitioning PTS on various types of modulation formats and subcarriers.

Windowing Techniques for Reducing PAPR of OFDM in Li-Fi Systems

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Ayad Atiyah Abdulkafi ◽  
Ibrahim Khalil Sileh ◽  
Saad Mshhain Hardan
Keyword(s):  
Time Domain ◽  
Orthogonal Frequency Division Multiplexing ◽  
Dynamic Range ◽  
Average Power ◽  
Nonlinear Behavior ◽  
Papr Reduction ◽  
Time Domain Signal ◽  
Ofdm Signal ◽  
Nonlinear Distortions ◽  
Ber Performance

AbstractIn this paper, Li-Fi system based on orthogonal frequency division multiplexing (Li-Fi-OFDM) is presented. In these systems, light-emitting diodes (LEDs) are used to send information data using intensity modulation. LEDs have a limited dynamic range and the voltage-current characteristic shows a nonlinear behavior. Li-Fi-OFDM signal is used to drive these transmitter LEDs. However, LEDs chip overheating and nonlinear distortions occur, due to high peak-to-average power ratio (PAPR) of the OFDM signal. The proposed approach develops a new PAPR reduction method of OFDM in Li-Fi systems based on time-domain windowing techniques. Several windows such as rectangular, Hanning and raised cosine methods have been applied to the OFDM time-domain signal in order to reduce its PAPR while maintain acceptable bit error rate (BER) performance at receiver side. The simulation results of the work have shown the advantages of the offered method; the proposed scheme achieves a significant PAPR reduction compare to the unwindowed signals. Our proposed system also slightly improves the BER performance for all windowing methods employed.

scholarly journals Efficient T-OOFDM System to Mitigate the Dispersion of Long-Haul Optical Fiber Channel at Wans

2018 ◽  
Vol 25 (3) ◽  
pp. 5-11
Author(s):  
Mohammed Shweesh Ahmed
Keyword(s):  
Fiber Optics ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Single Mode ◽  
Single Mode Fiber ◽  
High Data ◽  
Data Rates ◽  
Fiber Channel ◽  
Transmitted Signal ◽  
Channel Dispersion

Due to its attractive features, the utilization of fiber optics as a transmission medium with various applications is increased rapidly. In despite, when signals are transmitted with high data rates through ultra-long haul distances of single-mode fiber (SMF), which is usually used at wide area networks (WANs), the nonlinear dispersion of signals is raised. This phenomenon leads digital pulses to interfere with the adjacent pulses. In this paper, an optical orthogonal frequency division multiplexing based T-transform (T-OOFDM) system is proposed to mitigate the effect of fiber dispersion significantly and reduce the peak-to-average power ratio (PAPR) of the transmitted signal when compared with conventional optical OFDM (OOFDM) system. Simulations results confirmed by the analytical analysis demonstrated that the detrimental effects arising from fiber channel dispersion on the subcarrier orthogonality of the transmitted signals can be efficiently minimized by using T-OOFDM system. Moreover, the peak of the transmitted signal will be considerably reduced whilst preserving the average power of signals.

scholarly journals Performance Analysis of Selective Mapping in Underwater Acoustic Orthogonal Frequency Division Multiplexing Communication System

2021 ◽  
Vol 11 (1) ◽  
pp. 6696-6702
Author(s):  
W. Raza ◽  
X. Ma ◽  
A. Ali ◽  
A. Ali ◽  
A. Raza ◽  
...  
Keyword(s):  
Fading Channels ◽  
Communication Networks ◽  
Orthogonal Frequency Division Multiplexing ◽  
Average Power ◽  
Error Rates ◽  
Frequency Division Multiplexing ◽  
Frequency Division ◽  
Underwater Communications ◽  
Nonlinear Distortions ◽  
Selective Mapping

Under-Water Acoustic (UWA) communication networks are commonly formed by associating various independent UWA vehicles and transceivers connected to the bottom of the sea with battery-operated power modems. Orthogonal Frequency Division Multiplexing (OFDM) is one of the most vital innovations for UWA communications, having improved data rates and the ability to transform fading channels into flat fading. Moreover, OFDM is more robust on Inter-Symbol and Inter-Carrier Interferences (ISI and ICI respectively). However, OFDM technology suffers from a high Peak to Average Power Ratio (PAPR), resulting in nonlinear distortions and higher Bit Error Rates (BERs). Saving power of battery deployed modems is an important necessity for sustainable underwater communications. This paper studies PAPR in UWA OFDM communications, employing Selective Mapping (SLM) as a tool to mitigate PAPR. The proposed SLM with the oversampling factor method proves to be less complex and more efficient. Simulation results indicate that SLM is a promising PAPR reduction method for UWA OFDM communications reducing BER.

scholarly journals A 100 Gbps OFDM-Based 28 GHz Millimeter-Wave Radio over Fiber Fronthaul System for 5G

Optics ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 70-86
Author(s):  
James Dzisi Gadze ◽  
Reynah Akwafo ◽  
Kwame Agyeman-Prempeh Agyekum ◽  
Kwasi Adu-Boahen Opare
Keyword(s):  
System Performance ◽  
Direct Detection ◽  
High Capacity ◽  
Digital Signal ◽  
Data Rate ◽  
Radio Over Fiber ◽  
Data Traffic ◽  
Modulation Formats ◽  
High Data ◽  
Receiver System

Due to the unprecedented growth in mobile data traffic, emerging mobile access networks such as fifth-generation (5G) would require huge bandwidth and a mobile fronthaul architecture as an essential solution in providing a high capacity for support in the future. To increase capacity, utilizing millimeter waves (mm-waves) in an analog radio over fiber (RoF) fronthaul link is the major advancement and solution in achieving higher bandwidth and high data rate to cater for 5G mobile communication. In this paper, we demonstrate the feasibility of transmission and reception of a 100 Gbits/s data rate link at 28 GHz. The performance of three modulation formats (16-PSK, 16-QAM and 64-QAM) have been compared for an optical fiber length from 5 km up to 35 km for two detection systems; coherent and direct detection. Also, in this paper, the transmission impairments inherent to transmission systems are realized through the implementation of a digital signal processing (DSP) compensation scheme in the receiver system to enhance system performance. Quality factor (QF) and bit error rate (BER) are used as metrics to evaluate the system performance. The proposed system model is designed and simulated using Optisystem 16.

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