Minimum Bit Error Rate Research Articles

Transmission (2Gbps) over optical fiber cable by using radio over fiber and wavelength division multiplexing techniques

In recent years, there has been a growing and continuous demand for great (data rates) beyond existing wired and wireless networks. Radio-over-Fiber technology is considered as an efficient and practical solution for providing broadband wireless. In this paper, many techniques are used to implement a system that has the capability to provide a great bit rate, broadband bandwidth, and minimum cost. So Radio-over-Fiber technology was used to modulate the light with radio-signal and transmission the signals through an optical fiber cable. Wavelength-Division-Multiplexing technique was used to send many signals through the same link, and Subcarrier Multiplexing-Amplitude Shift keying as a modulation format. 2Gpbs separate on two channels was transmitted on Single-Mode Fiber. The average results obtained from our experience was as follows: maximum Q factor average = 4.9712925, minimum BER average = 3.63*10-7, total power average (dBm) = -51.1502, the OSNR average (dB) = 52.085 for channel_1. The results of channel_2 were: maximum Q factor average = 5.5901325, minimum BER average = 1.26*10-8, total power average (dBm) = -46.60135, the average of optical signal-to-noise ratio (dB) = 54.65. All the average result that has from our simulation was very good and acceptable. The simulation and performance test of our experience was done using Optisystem 7.0.

Performance evaluation of hybrid modulation techniques for high speed radio over fiber communication system

In Radio over Fiber (RoF) technology, the optical network capacity is integrated with the wireless network. The main objective of this work is to enhance the performance behavior of optical fiber communication system in terms of BER, Received Power and Q-Factor. The proposed combined modulation technologies, such as Pulse Amplitude Frequency Modulation (PAFM), Differential Phase Shift Keying Amplitude Modulation (DPSKA), Offset Quadrature Phase Shift Keying Amplitude Modulation (OQPSKA), Quadrature Amplitude Frequency Modulation (QAFM), Frequency Phase Modulation (FPM) and Pulse Amplitude Phase Modulation (PAPM), are used to meet this objective. The input data are used for modulating the electrical carrier signal with a frequency of 250 and 255[Formula: see text]GHz. This hybrid modulation technique obtained the minimum BER of about [Formula: see text] in FPM technique. The maximum Q-Factor of 33 is obtained in QAFM technique. The obtained maximum received power is 0.79[Formula: see text]mW in OQPSKA technique.

Comparative analysis of MIMO-based FSO and MIMO-based MGDM communications

The ever-growing need for high data rate, bandwidth efficiency, reliability, less complexity, and less power consumption in the communication systems is on the increase. Modern techniques have to be developed and put in place to meet these requirements. In the last few years, free space optical (FSO) communication systems have attracted considerable research efforts mainly due to their inherent potential transmission capacity, much higher than that offered by radio transmission technologies. However, despite of great potential of FSO communication, its performance is limited by the adverse effects (viz., absorption, scattering, and turbulence) of the atmospheric channel. Different studies on weather conditions and techniques employed to mitigate their effect are studied. On other hand, a MMF network may constitute the backbone network that feeds fixed-wired services (e.g. voice telephony) as well as wireless services (e.g. IEEE 802.x) throughout the building. The large bandwidth makes MMF a very attractive medium for low-cost broadband in building networks, in which several independent sets of services are integrated. In addition, research has shown that compared to conventional single-input single-output (SISO) systems, multiple-input multiple-output (MIMO) can actually increase the data rate of a communication system, without actually requiring more transmit power or bandwidth. In this paper, we develop a comparison between MIMO over multimode fiber (MMF) using MGDM and MIMO based FSO links. The achievable performance improvements, including received power levels, bit error rate (BER), and quality factor (Q-factor) are presented. Numerical results are obtained for single-input single-output (SISO) as well as for multiple-input multiple-output (MIMO) configurations. Simulation results show that MMF outperforms FSO links in terms of max Q-factor, minimum BER, and eye diagram. Seen that the dependence of the FSO system performance on the weather conditions is one of the most significant FSO limitations, we analyze the performance of FSO under clear, haze, and fog conditions using Q-factor, bit error rate (BER), etc., at varied distances. From the results, it can be concluded that as we move from clear weather conditions to haze and fog weather conditions, Q-factor of the received signal decreases.

The Engagement of Hybrid Dispersion Compensation Schemes Performance Signature for Ultra Wide Bandwidth and Ultra Long Haul Optical Transmission Systems

This paper presents the performance signature of the engagement of hybrid symmetrical hybrid compensation techniques for ultra wide bandwidth and ultra long haul optical transmission systems. These schemes that are namely optigrating, ideal dispersion compensation fiber Bragg Grating (IDCFBG), and dispersion compensation fiber (DCF). The combination of mixing these techniques together which is called hybrid symmetrical dispersion compensation techniques in that case. The employment of these mixing schemes is in symmetrical configuration with the presence of Erbium doped fiber amplifiers in order to upgrade optical fiber system capacity to reach transmission distance up to 432 km and transmission data rate up to 320 Gb/s. Maximum signal quality factor, minimum bit error rate (BER), output optical signal to noise ratio, electrical received power after APD photodetector, noise figure, and gain are the major interesting performance parameters for measuring the system operation efficiency. It is observed that the optimum case for maximum quality factor and minimum BER is achieved with 15 m EDFA amplifier length and 150 mW EDFA pump power.

Performance Analysis of Radio over Fiber Simulation Model using DPSK Modulation Technique

In this paper, performance analysis of radio over fiber (ROF) system has been proposed to analyze the performance of the system using differential phase shift keying method. RoF Systems exhibits the unique characteristic of combining the featuring of fiber optic link and free space radio path which brings many advantages and challenges to new mobile networks. RoF systems has the provision of large bandwidth and has fewer losses for the transmission that make the ROF suitable for the future wireless broadband services and fulfill demands of high data rate. The proposed simulation model helps in improving the system capacity and their effects on the output in terms of Q factor, minimum BER is analyzed by using optisystem software.

Performance Analysis of FSO DF Relays with Log-Normal Fading Channel

Abstract This paper studies the bit error performance analysis of decode-and-forward (DF) relays-based free-space optical (FSO) communication systems using avalanche photodiode (APD). The system uses subcarrier intensity binary phase shift keying (BPSK) modulated signals and subjects to scintillation due to optical turbulence. A log-normal random process is considered to model the received signal intensity fluctuation for a clear-air condition (weak atmospheric turbulence) scenario. Mathematical expressions of the average bit error probability and bit error rate (BER) are derived by taking into account the impact of atmospheric loss, thermal-noise and shot-noise limited conditions. It can be inferred from the numerical results that using DF relay nodes can extend the transmission distance and minimize BER performance of FSO system significantly compared with the direct transmission. Moreover, the selection of APD’s gain values is essential to minimize the system’s error rate performance. Therefore, the system could achieve the minimal BER by selecting an optimal average APD gain value appropriately. Moreover, the optimal average gain values of APD significantly depend on various conditions, such as the bit rate, total transmitted power, and the number of relay nodes.

Outage probability and average BER estimation of FSO system employing wavelength diversity

Free space optical (FSO) communication has gained significant attention among researchers for high bandwidth and secured data transfer applications. However, its performance is limited by the local atmospheric conditions. This paper focusses on an FSO system employing a diversity method to compensate signal loss occurred due to atmospheric turbulence conditions varying from moderate to strong. We derive a closed-form expression for two important parameters, viz.: average bit error rate (BER) and outage probability over gamma–gamma distribution channel. The numerical results for different combining schemes are presented in this paper. Enhancement in reliability and performance of FSO communication system with wavelength diversity is investigated. Effect of different wavelengths 850 nm, 1310 nm and 1550 nm on average BER is analysed and minimum BER is achieved for optimal combining at 1550 nm at diversity order $$R=3$$ .

Temperature effects on characteristics and performance of near-infrared wide bandwidth for different avalanche photodiodes structures

In this paper, the influences of thermal and spectral variations on various structures of avalanche photodiodes (APDs) have been deeply investigated. The characteristics and performance of Silicon (Si), Gallium Arsenide (GaAs) and Indium Gallium Arsenide (InGaAs) avalanche photodiodes have been evaluated under effects of different temperature degrees. The impacts of different temperature levels on the band gap energy, detector responsivity, noise equivalent power (NEP), cut-off wavelength, dark current and the photocurrent are studied and analyzed in details. The signal to noise ratio (SNR) and Bit Error Rate (BER) of these APDs are also computed and measured under the influences of different temperature levels and spectral variations. The aim of this paper is to determine the most efficient avalanche photodiode achieving the best performance according to the maximum SNR and minimum BER at high temperature environments. The analysis of the proposed model is performed by MATLAB. It was found that the experimental measured results endorse the analytical computed results. Further, it was observed that the APD (InGaAs) provides performance better than other APD structures in terms of larger SNR and less BER at higher temperature levels. Also, the temperature has a slight effect on the performance of APD (GaAs). So, it is seemed to be stable more than other APD structures and recommended to be used in warm environments and for high temperature applications.

Minimum BER Power Allocation for Space-Time Coded Generalized Frequency Division Multiplexing Systems

In this letter, we propose a minimum BER (MBER) power allocation (PA) method for generalized frequency division multiplexing (GFDM) systems with zero forcing receiver. The MBER PA of GFDM systems is solved through minimizing noise enhancement factor at the receiver. Additionally, theoretical BER and achievable rate (AR) expressions are derived with the proposed PA strategy. Furthermore, we also generalize the MBER PA strategy in space-time coded (STC) GFDM systems. Simulation results show that, no matter GFDM or STC GFDM systems, the proposed PA strategy could improve BER and AR performances simultaneously.

A multi-user linear equalizer for uplink broadband millimeter wave massive MIMO

Most previous work on hybrid beamforming millimeter wave (mmWave) communications and massive multiple input multiple output (MIMO) systems focused on narrowband channels. However, it is expected that the mmWave channels will be wideband, and for that reason, it is important to design solutions for frequency-selective channels. Therefore, in this paper, we consider the design of a hybrid analog/digital multiuser linear equalizer for broadband mmWave massive MIMO systems, optimized using the bit error rate (BER) as a metric. For the digital part, a closed-form solution is obtained by showing that the minimum mean square error (MMSE) and minimum BER solutions are identical. The analog part, which is assumed to be the same for all subcarriers, is computed iteratively over the radio frequency (RF) chains, and it is shown that the solution obtained in a previous iteration may be updated inexpensively to obtain a solution for the current iteration. The simulation results show that the performance gap between the proposed hybrid broadband multiuser equalizer and full digital equalizer decreases monotonically and exponentially with the number of RF chains until reaching zero. Moreover, the gap decay rate is faster for sparser mmWave channels, where fewer RF chains are required to achieve the same performance of the full digital architecture.

Bit-error rate based Doppler estimation for shallow water acoustic OFDM communication

Orthogonal frequency division multiplexing (OFDM) has drawn extensive attention in the field of underwater acoustic (UWA) communication due to its advantages of high transmission rate and high spectrum efficiency. Unfortunately, the practical application of OFDM in UWA communication is subject to severe multi-path as well as Doppler sensitivity. To overcome the impact of Doppler, generally the value of Doppler is estimated by searching the best correlation with the standard copy in time or frequency domain, to enable Doppler compensation via the resampling. However, it has been recognized that, at the presence of diffuse or time varying multi-path, the Doppler estimated by searching signal-level correlation may cause significant mismatch and thus deteriorate the demodulation. The reason is that, while the Doppler is searched in terms of signal-level correlation function, the purpose of the demodulation is to achieve the minimum bit error rate (MBER) at bit-level. In this paper, a Doppler estimation method based on BER search is proposed to transform the signal-level Doppler estimation into a bit-level one. Finally, numerical simulation and sea trial experiments under different Doppler scenarios are performed to verify the effectiveness of the proposed Doppler estimation method.

Analysis using multiple free space optic channel with amplification to mitigate haze attenuation

Weather severity has unfavorable effect on FSO transmission performance. The impact could result in poor quality of transmission and communication failure. This paper presents the analysis using multiple free space optic channels with amplification to mitigate haze attenuation. The visibility is progressively reduced due to the attenuation effects, causing the bit error rate to increase. Three designs of FSO system are proposed in this research as they are simulated and analysed thoroughly using Optisys software. The achieved result shows improved performance for Design 3, as the minimum BER achieved is 10<sup>-127</sup> when the power received is -26 dBm, and maximum Q-factor of 23.6 at the aperture diameter of 40 cm. It is proved to improve the system efficiently in low visibility condition compared to Design 1 and Design 2. It clearly has shown the superior capabilities of Design 3 to intercept and mitigate the atmospheric attenuation in haze condition as the power loss during transmission also reduced significantly.

Performance enhancement of overall LEO/MEO intersatellite optical wireless communication systems

SummaryThis paper has deeply investigated the performance signature of modulation techniques based low earth orbit (LEO)/medium earth orbit (MEO) intersatellite optical wireless communication systems for possible communication coverage distance of 20 000 km with possible transmission bit rate of 0.5 Tb/s. These modulation techniques that are namely multilevel quadrature amplitude modulation (M‐QAM), multilevel phase shift keying (N‐PSK), multilevel pulse amplitude modulation (H‐PAM), and finally multilevel differential phase shift keying (L‐DPSK) based on different electrical pulse generators for upgrading LEO/MEO intersatellite link operation efficiency. These pulse generators that are namely Gaussian pulse generator (GPG), hyperbolic secant pulse generator (HSPG), and raised cosine pulse generator (RCPG). The variations of maximum Q‐factor, minimum bit error rate (BER), and optical signal‐to‐noise ratio in relation to number of bits/symbol for different modulation techniques can be deeply studied in the presence of vertical cavity surface emitting laser (VCSEL). This study is done with using Optiwave system simulation version 7 for different modulation techniques, and all figures are sketched with using wizard Excel sheet set up. It is observed that maximum Q‐factor and minimum BER are optimized with using GPG and 8‐PAM, as well as 4‐DPSK with both HSPG and RCPG.

A 64 Gb/s Low-Power Transceiver for Short-Reach PAM-4 Electrical Links in 28-nm FDSOI CMOS

A four-level pulse-amplitude modulation (PAM-4) transceiver operating up to 64 Gb/s in 28-nm CMOS fully depleted silicon-on-insulator (FDSOI) for short-reach electrical links is presented. The receiver equalization relies on a flexible continuous-time linear equalizer (CTLE), providing a very accurate channel inversion through a transfer function that can be optimally adapted at low frequency, mid-frequency, and high frequency independently. The CTLE meets the performance requirements of CEI-56G-VSR without requiring the decision feedback equalizer (DFE) implementation. As a result, timing constraints for comparators in data and edge sampling paths may be relaxed by using track-and-hold (T&H) stages, saving power consumption. At the maximum speed, the receiver draws 180 mA from 1-V supply, corresponding to 2.8 mW/Gb/s only. The transmitter embeds a flexible feed-forward equalizer (FFE) which can be reconfigured to comply with legacy standards. A comparison between current-mode (CM) and voltage-mode (VM) TX drivers is proposed, proving through experiments that the latter yields larger PAM-4 eye openings, thanks to the intrinsically higher speed. The full transceiver (TX, RX, and clock generation) operates from 16 to 64 Gb/s in PAM-4 and 8 to 32 Gb/s in non-return-to-zero (NRZ), and supports 2× and 4× oversampling to reduce data rate down to 2 Gb/s. A TX-to-RX link at 64 Gb/s, across a 16.8-dB-loss channel, reaches 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-12</sup> minimum bit-error rate (BER) and 0.19-UI horizontal eye opening at BER = 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-6</sup> , with 5.02 mW/Gb/s power dissipation.

An efficient dispersion compensating AMI–SSP technique utilizing DCF supporting 100 Gbps Radio over Fiber system

In this paper, an Alternate Mark Inversion–Symmetrical–Symmetrical-Post (AMI–SSP) dispersion compensation technique has been proposed and tested for mitigating dispersion effects in Radio over Fiber (RoF) system to improve the RoF link performance. In comparison with other existing dispersion compensation techniques, the proposed AMI–SSP technique provides better performance as the simulation is performed at a high data rate (up to 100 Gbps) covering large transmission distance (up to 700 km). Using eye diagram, it is seen that the AMI–SSP technique provides maximum eye opening, high Q-factor (11.93) and minimum BER (3.46e−33) for 100 Gbps data rate at 700 km transmission distance for the deployment of RoF system.

Performance Limits of FSO Based SAC-OCDMA System Under Weather Conditions

AbstractIn this paper, the Spectral Amplitude Coding Optical Code Division Multiple Access (SAC-OCDMA) is investigated in Free Space Optics (FSO) using Zero Cross Correlation (ZCC) codes to evaluate its performance limits in terms of link range. The system is analyzed under clear, haze, moderate fog and dense fog weather conditions. This system has been evaluated numerically and by simulation analysis by maintaining the transmitted power at 10 dBm, for safety reason, according to International Telecommunication Union (ITU) and minimum acceptable BER of10{10}–9. The simulation results shown that the present system can transmit 622 Mbps/1 Gbps up to maximum link range of 1450 m/1100 m and 61 m/54 m under clear and dense fog conditions, respectively.

Influence of Conventional Optical Amplifiers for 64×10 Gbps WDM System

Abstract In this work we have investigated semiconductor optical amplifier (SOA), erbium-doped fiber amplifier (EDFA) and RAMAN Amplifier separately under 64 channels WDM system at 10 Gbps data rate. A comparison is made based upon the values of Q- factor, bit error rate (BER), and power received for different values of laser (present at the transmitter) power. The eye diagram for the three optical amplifiers has also been analyzed. Also the performance factors (Q- factor, BER, and power received) are evaluated for different values of fiber length. In general it is observed that with respect to the power received for a particular laser power (at the transmitter) and up to a fiber length of about 120 km Semiconductor optical amplifier (SOA) gives the best result among all the three amplifiers. With respect to the quality (Q) – factor the RAMAN Amplifier gives slightly better result for a given laser power and for a short fiber length (up to a fiber length of 50 km). For long distance (fiber length greater than 160 km) the Q – factor for all the three optical amplifier saturates and become equal. In terms of Bit Error Rate, RAMAN amplifier is best as it gives minimum BER at a given laser power but up to the fiber length of 70 km EDFA provides minimum BER.

BER performance analysis of coherent SIMO FSO systems over correlated non-Kolmogorov turbulence fading with nonzero boresight pointing errors

Abstract In this paper, the effects of nonzero boresight pointing errors on the average bit-error rate (BER) performance of coherent single-input multiple-output (SIMO) free-space optical (FSO) communication systems applying maximal ratio combining (MRC) over correlated non-Kolmogorov turbulence fading are investigated. The non-Kolmogorov turbulence fading is modeled using Gamma–Gamma distribution. Novel closed-form expression is derived for evaluation of the average BER performance for the system under consideration. Analytical results are provided to evaluate the average BER performance with the presence of correlated Gamma–Gamma channels and nonzero boresight pointing errors. It is worth noting that there exist an optimum radius of the ring where all the receivers are located to achieve the minimum BER for a given average signal-to-noise ratio value. The validity of the obtained mathematical expression is illustrated by Monte Carlo simulations. This work will help with further investigation of the fading correlation and the design of FSO communication systems.

A closed-form expression for performance optimization of subcarrier intensity QAM signals-based relay-added FSO systems with APD

This study characterizes the overall bit-error-rate (BER) performance optimization of avalanche photodiode (APD) receiver-based amplify-and-forward (AF) relay-added free-space optical (FSO) communication system. The system of interest uses subcarrier intensity quadrature amplitude modulation (QAM) signals and subjects to scintillation due to optical turbulence. A weak atmospheric turbulence (clear-air condition) scenario is considered, for which the received signal intensity fluctuation can be modeled as a log-normal random process. A closed-form expression of the overall BER is derived by taking into account the impact of atmospheric loss, turbulence strength, thermal-noise and shot-noise limited conditions. It can be inferred from the numerical results that using AF relay nodes can extend the transmission distance and minimize BER performance of FSO system significantly compared with the direct transmission. Moreover, the selection of APD’s gain values is indispensable to minimize the system’s BER performance. Hence, the designed system could achieve the minimal BER by selecting an optimal APD gain value appropriately. In addition, the optimal gain values of APD significantly depend on various conditions, such as noise temperature, link distance, and the number of relay nodes.

Evaluation of FSO System Availability in Haze Condition

In this paper, we proposed the evaluation of FSO system availability in haze condition. The atmospheric attenuation by weather conditions in the atmosphere as the most challenging problem of FSO system as the system performance is severely degraded and causing the signal optic to be transmitted poorly. The effects of haze condition on the performance of FSO system is stressed out and focused in this paper. From the evaluation of the analysis, designs of FSO system are proposed to obtain a system with improved link performance in haze conditions. The scattering coefficient and the atmospheric attenuation are determined using Beer’s Lambert equation. From the research, the link performance of the system is greatly improved using Design 2 with minimum BER of 10-127127 and maximu m Q Factor of 23.98. The FSO system using Design 2 has better performance compared to Design 1 in haze condition as the optical signals could penetrate the dense haze better without losing much optical power during the transmission to the scattering.