Bit Error Rate Values Research Articles

BER and outage throughput analysis of DPIM/DHPIM coded QPSK-OFDM based outdoor optical wireless communications

With the growing demand for fast and reliable communication systems, particularly in outdoor environments, it is essential to investigate advanced encoding techniques. Digital Pulse Interval Modulation (DPIM) and Dual Header Pulse Interval Modulation (DHPIM) emerge as promising alternatives to traditional line coding methods, providing enhanced spectral efficiency and resistance to signal disruptions. This paper presents the performance of a Quadrature Phase-Shift Keying (QPSK) Orthogonal Frequency Division Multiplexing (OFDM)-based Optical Wireless Communication (OWC) system using these advanced encoding schemes. The analysis includes simulation results on QPSK-OFDM-based transmitter design, free space optical channel modeling based on Gaussian and log-normal distribution atmospheric turbulence, and recovery of input digital stream using the mentioned line coding techniques. The results demonstrate optimal bit error rate (BER) values for the QPSK-OFDM-based OWC system. The primary innovation of this research lies in the encoding schemes and their performance in outdoor optical wireless communication systems under turbulent conditions. Through extensive simulations and analysis, detailed insights into the bit error rate and outage throughput characteristics of DPIM/DHPIM coded QPSK-OFDM are provided, offering a unique perspective on the performance of these schemes in real-world scenarios. The findings not only highlight the optimal BER values achievable with the QPSK-OFDM-based OWC system but also offer insights into the system's ability to overcome transmission challenges under various atmospheric conditions.

Development of a Technique for Mitigating Four-Wave Mixing Effect in Dense Wavelength Division Multiplexing System Using DP-QPSK with Channel Spacing

A Dense Wavelength Division Multiplexing (DWDM) system is a vital component in the optical network for the transmission of high data over a long distance. However, the non-linear effect of Four-Wave Mixing (FWM), one of the critical non-linear effects, limits the channel capacity and the amount of data that the DWDM system transmits. Intensity Modulation formats and Channel Shuffling algorithms being used to overcome the impact of FWM in DWDM are unable to sufficiently suppress the FWM effect due to limited capacity. This research, therefore, examined the mitigation of the FWM effect in the DWDM system using Dual Polarization Quadrature Phase Shift Keying (DP-QPSK) and channel arrangement. The DP-QPSK was designed and implemented using 100 GHz for both Equal Space Channel Allocation (ESCA) and Unequal Space Channel Allocation (USCA). It was analysed on a 64-channel DWDM system operating at 100 Gbps capacity over a transmission distance of 1000 km. The DP-QPSK-based ESCA and USCA techniques were simulated using OptiSystem 17 simulation software and Python for data analysis. The performance of the system was evaluated using bit error rate (BER), optical signal-to-noise ratio (OSNR) and Electrical Constellation Diagram. Validation was done with other advanced modulation formats: Quadrature Phase Shift Keying (QPSK) and Differential-Quadrature Phase Shift Keying (D-QPSK). The DWDM system using DP-QPSK gave better performance due to the highest OSNR and BER values obtained when compared with ESCA-based QPSK and D-QPSK techniques. The technique can be used to suppress the effect of FWM in optical communication systems.

Perfect vortex Laguerre-Gauss beams as a carrier in the MMF/FSO communication system

This paper presents a novel, to the best of our knowledge, high-speed transmission system that integrates a new structured light beam, specifically the perfect vortex Laguerre-Gaussian (PVLG) beam, with an optical code division multiple access (OCDMA) system utilizing a premutation vector (PV) code. The PVLG beams are distinguished by their unique shape, which remains nearly invariant during propagation regardless of the azimuthal order of the orbital angular momentum (OAM), facilitating the multiplexing of multiple OAM beams within the same spatial area. Additionally, the system employs hybrid multimode fiber (MMF) and free space optics (FSO) channels, with consideration of foggy weather conditions in the FSO channel. A comparative analysis between the performance of PVLG beams and standard LG beams is conducted. Performance evaluation metrics include the Q-factor, bit error rate (BER), and eye diagrams, providing comprehensive insights into received signal quality. The results demonstrate that the system utilizing PVLG beams outperforms the one using standard LG beams. Specifically, the system achieves a maximum MMF length of 0.35 km with a BER of approximately 10−4 and a Q-factor of around three when the MMF cable channel is used only. For the FSO channel, the achievable ranges are 1.1 km, 0.7 km, and 0.35 km under low fog (LF), medium fog (MF), and high fog (HF) conditions, respectively, maintaining the same BER and Q-factor values. Moreover, the hybrid MMF/FSO channel extends the transmission range to 1.2 km under LF conditions and to 0.45 km under HF conditions, with consistent BER and Q-factor values. Each of the four PVLG beams carries 40 Gbps, resulting in a total transmission capacity of 160 Gbps. Thus, the proposed system is well positioned to meet the high-speed data transmission demands of next-generation 6G networks.

Comparing the Performance of Optical Communication Links using G.652 and G.655 Fiber in Python Packages

This study investigates and compares the performance of a 10 Gbps optical communication link utilizing two prevalent single-mode fibers: G.652 and G.655. The analysis employs both theoretical calculations and Python-based simulations to assess the effectiveness of each fiber type in this high-speed transmission scenario. With the ever-growing demand for bandwidth in communication networks, 10 Gbps transmission systems are becoming increasingly commonplace. Single-mode fibers like G.652 and G.655 play a vital role in these systems, offering low signal attenuation for long-distance data transmission. However, each fiber type exhibits distinct dispersion characteristics, which can impact signal integrity over extended distances. This investigation adopts a two method for performance evaluation. Firstly, link power budget calculations are performed to determine the optical signal power before and after propagating through a 50-kilometer fiber span. The received power serves as the foundation for subsequent Q-factor and Bit Error Rate (BER) analysis. These calculations establish the theoretical limitations of the system based on well-defined formulas. Secondly, Python-based simulations are conducted to corroborate the theoretical findings and provide a more comprehensive performance assessment. This approach leverages the capabilities of two prominent Python packages: Opticomlib and OpticommPy. Opticomlib excels at analyzing the behavior of individual optical pulses within the system, enabling an understanding of the signal propagation. On the other hand, OpticommPy specializes in parameter sweep analysis, allowing for the investigation of how critical parameters like received power influence the Q-factor. By combining these functionalities, the simulations provide a detailed picture of the system's performance under various conditions. The calculated BER and Q-factor values for both G.652 and G.655 fiber links surpass the industry-accepted performance standards. These results demonstrate the effectiveness of using Python-based tools for comprehensive performance analysis of optical communication systems. However, it's important to note that slight discrepancies exist between the calculated and simulated results.

Evaluation of Joint Technique Iterative Clipping Filtering (ICF) and Neural Network Predistortion on SDR-based MIMO-OFDM System

Multiple-input, multiple-output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) is a communications technology that powers numerous modern communication systems, including 5G and WiFi-6. This technology is utilized in current communication systems due to its high performance and extensive channel capacity. MIMO-OFDM does have disadvantages, such as large Peak-to-Average Power Ratio (PAPR) values. If the signal is processed by a nonlinear Power Amplifier (PA) device, a high PAPR value signal can result in both in-band and out-of-band signal distortion. To combat high PAPR values, PAPR reduction strategies such as Iterative Clipping Filtering (ICF) are utilized. From this study, using ICF with iteration 2 and Clipping Ratios (CR) 3 and 4 can improve the system's minimum Bit Error Rate (BER) by about 22.8% and 91.1%, respectively. Choosing the correct CR will improve the system, but using the lower CR will make it worse than a system without ICF. This occurs in systems using ICF with iterations two and CR 2 and at the same SNR conditions as systems without ICF; using ICF with iterations two and CR 2 results in higher BER values. The use of Predistortion Neural Network (PDNN) can overcome this problem. By using PDNN, there is an improvement in the system where the minimum BER value can reach 0.1 × 10-5. The percentage decrease in BER from using PDNN for ICF with iterations two and CR 2, 3, and 4 is 99.88%, 99.86%, and 98.807%, respectively. Thus, the joint techniques of ICF and PDNN can significantly enhance the performance of MIMO-OFDM systems with nonlinear PA. Importantly, the experiment was conducted on an SDR device, ensuring the real-world applicability of the results.

HE EFFICIENT PERFORMANCE OF GENERALIZED SELECTIVE COMBINING TECHNIQUES ON RAYLEIGH FADING CHANNEL USING HYBRIDIZED MODULATION SCHEME

This study concentrated on improving Generalized Selective Combining (GSC), one of the widely used diversity combining methods in telecommunications, by combining the modulation schemes of Quadrature Amplitude Modulation (QAM) and Orthogonal Frequency Division Multiplexing (OFDM) over a Rayleigh Fading channel. These were done with the intention of delivering strong Quality of Service (QoS) in mobile communication, particularly with the goal of lowering Bit Error Rate (BER) to improve reception on the receiving end. According to the findings, the communication system’s performance efficiency was increased through the hybridization of the modulation schemes, with QAM (4 and 16 constellation being taken into consideration for this research) and OFDM, even though a Rayleigh Fading channel was used, preventing line of sight (LOS). Compared to the BER values obtained when the modulation schemes were not hybridized, GSC was considerably improved with a low BER. In light of the fact that the channel under consideration did not experience severe fading, which is what caused the low BER observed, this article indicates that GSC might be improved through the hybridization of modulation schemes to provide a good Quality of Services.

Concurrent M-QAM transmission performance assessment in a combined four SOA-MZIs arrangement

In this paper, the utilization of four semiconductor optical amplifier Mach-Zehnder interferometers (SOA-MZIs) is explored to achieve concurrent M-QAM (M-ary Quadrature Amplitude Modulation) transmission. Utilizing an actively mode-locked laser, we generate pulses with a duration of 0.5 ps at a repetition rate of 20 GHz, serving as our sampling source. The incoming M-QAM signals, spanning various frequencies, undergo down-mixing at the SOA-MZIs combined exit, resulting in diverse output frequencies by respecting the bandpass sampling procedures. The unparalleled simultaneous M-QAM transmission is assessed through critical metrics such as error vector magnitude (EVM) and bit error rate (BER). The SOA-MZI conversion efficiency (CE) exhibits a notable transition, ranging from 90 % at 76 GHz to 68 % at 84 GHz based on 1024-QAM data. The concurrent down-mixed signals showcase EVM values of 3, 2, 1, and 0.25 % for 16-, 64-, 256-, and 1024-QAM, respectively, at the first range of output frequencies. Besides, an exceptional BER value of 93×10−6 is attained at a symbol rate of 0.25 GSymb/s at 84 GHz for the 1024-QAM replica. A comparative analysis reveals that under identical parameter settings, the proposed Gaussian filter expounds lower EVM values compared to the root raised cosine (RRC) filter. These results highlight the success of the novel experimental approach employing SOA-MZIs for simultaneous down-mixing of four M-QAM carriers with varying levels, showcasing outstanding performance outcomes.

Performance analysis of a hybrid optical amplifier based 480-Gbps DWDM-FSO system under the effect of different atmospheric conditions

Free space optical (FSO) systems offer a desirable and affordable way of providing communication services in remote locations. They provide secure wireless transmission without the requirement for licensing and with lower implementation costs. However, due to the impact of atmospheric turbulences on the effectiveness of FSO systems, their implementation faces significant challenges. Dense wavelength division multiplexing (DWDM) has shown promise in addressing the growing bandwidth needs in optical networks. This paper introduces a hybrid optical amplifier based system, combining DWDM and FSO technology. Energy conservation in such a system involves optimizing various aspects to reduce power consumption while maintaining or improving performance. The proposed DWDM-FSO system operates at a rate of 480 Gbps and consists of 12 channels, each capable of transmitting data at 40 Gbps. The system's performance is evaluated and compared by determining the Q-factor and bit error rate (BER) for both the cases when hybrid amplifier is employed and with no hybrid amplifier within the C-band, specifically focusing on wavelengths around 1550 nm. Moreover, the length of the FSO link is increased to assess the corresponding Q-factor and BER. Resultantly, the maximum distance for the FSO link is determined, ensuring that it remains within acceptable Q-factor and BER thresholds. Furthermore, the FSO system's effectiveness is assessed and compared across various atmospheric conditions. The findings reveal that, in clear weather conditions, the FSO system achieves a maximum distance of 510 meters while maintaining satisfactory Q-factor and BER values when not utilizing a hybrid amplifier. However, by integrating a hybrid amplifier, the system's reach significantly extends to 1700 m under clear weather conditions, still maintaining acceptable Q-factor and BER values.

Coding techniques for diversity enhancement of dense wavelength division multiplexing MIMO‐FSO fault protection protocols systems over atmospheric turbulence channels

AbstractAn enhanced transmission is presented in a multiple‐input‐multiple‐output (MIMO) dense‐wavelength division multiplexed (DWDM) free‐space‐optical (FSO) communication link using diversity coding techniques under the effect of turbulent weather phenomenon. The findings show good performance with an (8 channels × 2.5 Gbps data rate/channel) 20 Gbps 1500 m transmission distance. The bit‐error‐rate (BER), outage probability (OP), and signal‐to‐noise ratio (SNR) of the diversity combining techniques using maximum‐ratio combining (MRC), selection combining (SC), and equal‐gain combining (EGC) technique are evaluated in this work. The obtained results illustrate that Alamouti, space‐time coding (STC), space‐time block coding (STBC), space‐time trellis code (STTC), orthogonal STBC (O‐STBC), and quasi‐orthogonal STBC (QO‐STBC) on the minimum mean‐square‐error, and MRC are worth implementing on the DWDM‐FSO wireless communication systems. The mitigation of atmospheric turbulence is achieved using MIMO diversity combining techniques coding. The simulation results for diversity coding techniques using QO‐STBC/STTC and SC/MRC in the MIMO‐DWDM FSO communication system can improve BER performance, OP, and SNR. The MRC exhibits the lowest OP and BER when compared with the SC and EGC. The numerical results demonstrate that the FSO communication link using DWDM QO‐STBC/STTC improves the power penalty at both BER values under varying atmospheric turbulence conditions for ST, MT, and WT, in comparison to FSO systems without DWDM QO‐STBC/STTC diversity coding techniques.

Performance evaluation of a UOWC system based on the FRS/OCDMA code for different types of Jerlov waters.

In this work, the fixed right shift (FRS) code is utilized for the optical code division multiple access (OCDMA) technique in an underwater optical wireless communication (UOWC) system. Additionally, in this system, a 532nm laser diode (LD) source is employed to generate optical signals. The investigation encompasses an analysis of five distinct Jerlov water types, each exhibiting diverse chlorophyll concentrations. The performance of the proposed system is evaluated when each channel that is assigned a unique FRS code sequence carries different data rates (2.5, 5, and 10Gbps). Underwater (UW) ranges, bit error rate (BER), eye diagrams, and quality factor (Q-factor) are the performance metrics used to evaluate the system performance. The proposed UOWC-FRS/OCDMA system is simulated, and the obtained results show that the eye diagram openings close, the BER increases, and the Q-factor decreases as the data rate per each channel increases from 2.5 to 10Gbps, and the attenuation of water becomes higher. Moreover, the lower attenuation values caused by the Jerlov type I (JI) waterbody allow each channel to carry 10Gbps of data to propagate longer UW for a range of 35m with a log(BER) ≤-6.33 and Q-factor greater than 4.9. On the other hand, at the same values of BER and Q-factor, the shortest ranges of 12 and 5.15m are obtained for JII and JIII waters, respectively, where their attenuation coefficient values are 0.5297 (JII) and 1.8998 m -1 (JIII). Furthermore, as our model uses three channels, the overall achieved capacity is 3×10G b p s=30G b p s.

Influence of different codes on the performance of SAC‐OCDMA over FSO link

SummaryThis paper evaluates the performance of a spectral‐amplitude‐coding optical code division multiple access (SAC‐OCDMA) system over a free space optical (FSO) communication link under various weather conditions such as fog, snow, and rain. The system uses different code families, including modified quadrature congruence (MQC), random diagonal (RD), and diagonal eigenvalue unity (DEU), to address user codes and reduce the effects of multiple access interference (MAI). The system's bit error rate (BER) performance has been analyzed taking into account receiver noises and MAI, and calculates the required optical power for a BER value of 10−9 under different weather conditions. The results show that fog has the most significant impact on the system's performance, while rainy conditions require the lowest optical power. The performance of the system also declines with increasing transmission length and concurrent user count. Finally, the paper compares the performance of different code families under unfavorable weather conditions and concludes that DEU performs better than MQC and RD in bad weather.

EDFA with power pump laser in WDM Network design of 10GBPS transmission

Wavelength Division Multiplexing (WDM) that enabled optical networks are currently widely used in current telecommunications infrastructures and are anticipated to play a significant role in next-generation networks and the future Internet, supporting a wide range of services with a wide range of bandwidth, latency, reliability, and other feature requirements. In WDM networks, the input power of an optical transmitter is crucial; as a result, this results in a good output signal at the receiver side. The purpose of this paper is to design a WDM Optical Network in terms of length and pump power. The system is simulated using Opti-System software to achieve bit error rate (BER), quality factor, and output power of EDFA through optimized fiber length and pump power. In this analysis, the BER value, Q-factor and output of the system have been evaluated between 1550 and 1552nm with 0 dBm input signal power. EDFA length of 5km, power pump value of 500mv and 980nm frequency was set as reference in this study. This system was analysed using Opti-System simulation software at 10 Gigabits per second (10GBPS) transmission system. Result have shown that, min BER value shows a very significant increase at a 9-meter length and the Q-factor was rapidly decrease. The min BER value was in range 10-11 and 10-19 and Q-factor range 6.5 to 9.1 for 200mW to 8000mW power pump.

Performance enhancement of 5G uplink MIMO over fading-shadowing, path losses, and ISI using LZF equalize

The challenges of the 5G mobile wireless communication systems transmission channels have been changed continuously because of the signal transfer path characteristics such as real-time applications, path loss, multiple users, reflected rays, channel Rayleigh-fading, shadowing, noise, and inter symbol interference (ISI). These challenges have been treated to reach the minimum bit error rate (BER) value of the received data and maximum data rate of high-speed wireless mobile communication systems. In this paper, the linear zero-forcing (LZF) equalizer with uplink multi-input multi-output (MIMO) system has been proposed to enhancement the BER, which is caused by the ISI, Rayleigh fading, shadowing, path losses, and additive white gaussian noise (AWGN). Furthermore, the proposed approach is applied to a different number of antennas constellation to show the effect of increasing the number of antennas on the BER. The results show that the proposed LZF equalizer-MIMO system model has reached lower BER values, and high performance with an increase in the receiver to 8×14, 8×16 and 8×18 antennas constellation at 8, 10, 12, 14, 16, and 18 dB signal to noise ratio (SNR).

Image Transmission Analysis using CSS Modulation Scheme

Image transmission through low-speed communication systems has been a challenge to overcome in the last few years. Actual IoT technologies are supported by LPWAN, where power consumption is a primary issue to consider. The image transmission study presented in this paper is based on Chirp Spread Spectrum (CSS) modulation scheme used by LoRa. A simulation model for image transmission is presented, where the communication channel is based on additive white Gaussian noise (AWGN), with a configurable signal-to-noise ratio (SNR). This model allows the modification of several LoRa CSS parameters such as: spreading factor (SF) bandwidth (BW) and code rate (CR). The adopted metrics for the evaluation of the proposed methodology are symbol error rate (SER), bit error rate (BER) and peak signal-to-noise ratio (PSNR). The first two figures of merit allow the study of the transmission quality and with the last one is possible to infer the received image quality. For a SF=8 and SNR=-10 dB the obtained values of SER and BER are 0.001 1e-4, respectively. These values will lead to a PSNR = 21 dB.

A robust watermarking approach against high‐density salt and pepper noise (RWSPN) to enhance medical image security

AbstractThis paper proposes a robust watermarking method against high‐density salt and pepper noise attacks. Automatic region of interest (ROI) detection, embedding encoded data, removing different densities of noise, data extraction by omitting, and labeling the noisy pixels of Region of Non‐Interest (RONI), and decoding the extracted data using ROI pixel information as a key, are various steps of the presented scheme. The automatic ROI detection method separates the RONI from ROI with four vertices of the smallest rectangle, for the embedding process. The encoded watermark data is embedded into the least significant bits of RONI in four neighbour pixels. Adaptive Removal of high‐density Salt and pepper Noise method can enhance image quality and reduce the effect of salt and pepper noise attacks. The embedded information is preserved from destruction if the host image is impaired through the power of robustness. The best results are obtained through the action of extracting the watermark from RONI pixels, utilizing the same ROI detection method. Omitting and labeling the noisy pixels of the RONI will ensure healthy extracted watermark data, leading to decreased Bit Error Rate (BER) values. Finally, these data are interpreted using the key of ROI pixels, and the watermark data is decoded and retrieved. Due to salt and pepper noise obliterating pixel bits and their corresponding transform coefficients in the transform domain, the spatial domain is employed to enhance robustness against such attacks. The results show the high performance of the presented scheme. The average BER value for five MRI databases in a 97% salt and pepper noise attack is 38.6.

SIMULASI SKEMA UNIVERSAL FILTERED MULTI-CARRIER (UFMC) PADA SISTEM KOMUNIKASI DIGITAL

Universal Filtered Multi-Carrier (UFMC) is a multi-carrier modulation scheme that is an alternative to the Orthogonal Frequency Division Multiplexing (OFDM) scheme currently used in 4G communication systems and wireless local area networks (WLAN). The weakness of OFDM lies in the high peak-to-average power ratio (PAPR) value and out-of-band (OOB) emission which can cause interference between carriers. UFMC is one of the schemes used to overcome the weaknesses of OFDM. This research aims to study the performance of UFMC for data transmission on AWGN channel with 256-QAM, 1024-QAM, and 4096-QAM modulation. In addition, 256-point, 512-point, and 1024-point FFTs were also used to see the effect on the achievable bit error rate (BER) and PAPR value. The simulation results show that for all simulated FFT sizes and QAM values, 256-QAM produces the lowest BER value. Using a 1024-point FFT, a BER of 10-3 can be achieved with an SNR of 20 dB. The lowest PAPR value obtained in the simulation is 7.1891 dB.

Performance Analysis of Free Space Optical Communication under Scintillation Effect

Free-Space Optical communication (FSO) offers unregulated bandwidth of up to 200 THz, security, higher speed, unlimited data rate and shortest installation time. However, weather attenuation, especially scintillation, has a massive impact on the performance of the FSO transmission channel. This paper evaluates link availability and effect of scintillation on FSO performance in terms of eye diagrams, Bit Error Rate (BER), Q-factor, and signal-to noise ratio. Our work used data collected from January 2018 to December 2021 by Tanzania Meteorological Authority (TMA) in Mwanza and Arusha regions for link availability and performance analysis. Simulation was performed to determine the FSO link availability, and we analyzed the scintillation effect on FSO performance using Submarine Laser Communication II and Hufnagel Valley (HV) day prediction models. It is observed that the HV day model performs better in predicting scintillation intensity compared to the former. In both regions, for the same transmission power of 20 dBm, the signal quality is better for a distance of 6 km where the BER value is found to be 10-8. These results suggest that, to achieve high-speed data transmissions, the maximum separating distance between FSO transceivers should not exceed 6 km.

Determination of the Bit Error Rate Due to Thermal Noise Using JoSIM Superconducting Circuit Simulator and the Monte Carlo Method

Thermal noise requires careful consideration during the design process of RSFQ circuits since it reduces circuit operating margins and can cause switching errors. Bit error rate (BER) provides a useful means of analysing the effect of this noise on a circuit. With tools developed under the IARPA SuperTools project, we present an implementation of the Monte-Carlo technique for determining BER via simulation. The Monte-Carlo method has been considered previously but not widely implemented due to slow simulation times preventing the determination of small BER values. We use JoSIM – an efficient simulator with SPICE syntax that allows for the simulation of superconducting components and noise sources with improved speed over older superconductor simulators. This speed improvement makes the Monte-Carlo method viable. The simulated BER is plotted against bias current with values in the low-BER region interpolated from the simulated values using MATLAB. We show how the results need to be used as a further qualifier of circuit performance for the characterization of a logic cell library.

Performance Analysis of the WDM Schemes for RoF System with Various Bit Rate

Communication that combines the methodologies of the two communications can be considered as communication fiber optic communication and can be used in communication systems and wireless. The integration of optical and wireless networks can function to increase mobility and capacity as well as reduce costs in access networks. Radio over fiber (RoF) can be a solution for many problems because it can control many base stations (BS) connected to a central station (CS) with an optical fiber. The high bit error rate (BER) and low Q factor value are caused by the Rof signal head received in low quality, so the receiver may not operate on high data speed networks. The solution to different signal problems and can be done with single mode fiber is the Wavelength Division Multiplexing (WDM) network. BER must be reduced to a guaranteed value, and the Q factor must be increased. WDM-RoF probes with different fiber lengths at various channel distances will be: simulated using Optisystem software, and the performance of the RoF receiver is measured and analyzed depending on the obtained BER, Q-factor value, and eye aperture height. The effects of degradation factors such as attenuation and dispersion are very limited with the addition of EDFA amplifier to Single Mode Fiber (SMF). The higher the bit rate of a communication system, the lower the performance of the system. In this study, analysis of the WDM-Rof system with bit rate variations was carried out to determine the bit rate value that still met the standard. From the simulation results, the Q-Factor and BER values at a bit rate of 11 Gbps do not meet the standards, i.e 4.50508 and 2.5390e-006.

Investigations on Filtered OFDM with Selective Mapping Method and Partial Transmit Sequence Technique for Future Generation Mobile Communication Systems

Future generation mobile communication system requires asynchronous transmission of data, reduced out-of-band power emission, low peak-to-average power ratio, low latency, high data transmission rate, better spectrum, energy, and power efficiency, etc. Investigations on suitable waveform candidates for future-generation mobile communication have been reported in this paper. Filtered Orthogonal Frequency Division Multiplexing (F- OFDM), F- OFDM with Selective Mapping Method (SLM), and F- OFDM with Partial Transmit Sequence (PTS) technique, have been investigated. Its performances have been evaluated in terms of peak-to-average power ratio (PAPR), bit error rate (BER), and out-of-band power emissions. F–OFDM is a suitable candidate for future-generation mobile communication systems that can be used with single-rate or multirate filters. It can also be used in combination with other PAPR reduction techniques. F-OFDM with PTS technique requires a smaller number of IFFT operations than F-OFDM with SLM. The result obtained from my present investigations reveals that F-OFDM with the PTS technique has 4.3 dB less PAPR than that of OFDM at the cost of marginal increase in the BER value.