BER Value Research Articles

The cell-free mMIMO networks: mathematical analysis and performance evaluation

One of the motivations towards the 5G cellular networks and beyond is the large increase in the supported data rate in both uplink and downlink. Deployment of small size cells, massive MIMO, wherein a large number of antennas are deployed at transmitters and receiver, are effective tools in these networks. Users under cell massive MIMO networks “mMIMO” can provide high data rate. However, the cell-edge user and users, under shadowing, can have a poor performance. Cell-Free networks can provide a satisfied data rate even for shadowed and cell-edge users. In this paper, cell-Free mMIMO networks are mathematically analyzed applying different cooperation mechanisms among the access points APs. Moreover, a new mathematical formula for the throughput, based on BER, is derived. Furthermore, closed formulas for the throughput-BER as well as energy efficiency (EE) performance are derived. Finally, the cognitive radio concept is proposed in order to limit the interference among users accessing the same resources in uplink. Simulation results show that the fully centralized cell-Free mMIMO network has a higher spectral efficiency and energy efficiency than the cellular mMIMO networks at different BER values especially when MMSE is applied. Furthermore, the cognitive radio theory can increase the SE and EE performance of the cell-Free networks when all cooperation mechanisms are applied.

PENGEMBANGAN MODUL PRAKTIKUM UNTUK PERBANDINGAN UNJUK KERJA SUMBER CAHAYA OPTIK LED DAN LASER DALAM SISTEM KOMUNIKASI OPTIK

LED optical light source and laser diode function as an information carriers in the opticalcommunication systems. Each optical light source in the form of LED, CW Laser, and VCSEL Laserhas advantages and disadvantages. Based on these advantages and disadvantages, a study wascarried out on the internal and external characteristics of optical light sources to determine the optimaloptical light source to use as needed. Simulations are carried out in optical system software. Theperformance analyzed is Q-Factor, BER, and Eye Diagram until it reaches the ITU-T G.984.2standard with a minimum limit of Q-Factor = 6 and BER = 10-9. The feasibility test of the practicummodule uses the method of filling out a questionnaire with a Likert scale of 1–5 and giving pre andpost-test to the practitioner. The results of this study were an increase in the internal characteristics ofthe LED, a decrease in the signal power of the CW Laser, and an increase in the bias current of theVCSEL Laser resulting in a decrease in Q-Factor, and an increase in the BER value. The comparisonof the increase in bit rate and transmission distance showed that CW Laser can transmit a higher bitrate and a longer transmission distance. The comparison of the transmission distance that can becovered by each optical light source shows that the CW Laser travels the farthest transmissiondistance . Increased understanding of the practitioner based on the post-test score which is higherthan the pre-test score can be used as the basis that this practicum module as a whole is verysuitable for use as teaching material. This is also supported by the feasibility test of the questionnairefilling method with a Likert scale of 1-5 with a percentage of the practitioner's assessment of 88.6%.

Performance Analysis of Inter-satellite Optical Wireless Communication (IsOWC) System with Multiple Transmitters/Receivers

The satellite communications networks have certainly been innovated recently by Inter-satellite optical wireless communication (IsOWC) networks. The prerequisite for next generation mobile satellite communication is superior multimedia facility for consumers at anytime and anywhere. The proposed optical communication system is designed and analysed to improve data transmission quality over the distance between two geostationary (GEO) satellites greater than 36000 km. This trend is to achieve high speed transmission with minimizing the presence possibility of free space loss in transmission that can occur in satellite communication via the longest range. Numerous transceivers IsOWC is a hopeful way to deal with be utilized related to different earth stations as a system utilized between the geosynchronous satellites. The wireless transmission creates the opportunity at high optical power without free space loss. The results of the simulated system showed that with 32 transmitters/receivers IsOWC, the Q-factor values of 36.526, 12.176 and 4.015 are obtained at 38000 km range at laser power of (19, 14 and 9) dBm, respectively. The proposed system is operated at 19 dBm optical power and different values of aperture size and the best values of Q-factor and BER are 41 and 10−250, respectively, for highest diameter value of 20 cm. The operation of the system with various values of bit rate is verified as well. It is seen that the best system performance is at 0.032 Gb/s bit rate and will be of lower as the bit rate increases until it roughly fixes at 32 Gb/s. This research offers the treatment for the transmission problem for ultra-speed application in mobile satellite systems.

Modelling and performance analysis of DWDM passive optical network

Passive optical networks are emerging as the main technology for building access networks. The current metropolitan optical communication networks operate at 1Gbps, which appears to be insufficient for the future development and exponential growth of traffic from IP services. The existing various traffic-intensive services and the growing interest in 4K video content and streaming services require the introduction of new solutions within passive optical networks (PON). A promising option is the combination of 10 Gbps and above high-speed data transmission with spectral multiplexing. DWDM will provide the required high spectral efficiency, but in contrast will require the use of a proper modulation scheme to achieve a longer distance. In this paper a model for performance analysis and solving optimization problems for DWDM-PON networks is developed. Different signal modulations are considered and a comparative analysis is performed. The behaviour of the system at different input parameters is modelled. Performance analysis is performed by evaluating the spectral characteristics and values of BER and Q-factor.

Design of OFDM system using Adaptive Modulation and Sparse Channel Estimation Method for long distance Underwater Acoustic Communication

Underwater Acoustic channels are the most challenging communication media. Achieving high data rate, a high throughput and a low latency for the time varying multipath channel is a tedious task.This work is focused on the designed for bandlimited UWA using Multicarrier OFDM system to get more throughput at the destination. To increase the performance , efficient adaptive modulation process and estimation of channel is implemented on UWA system.Here the adaptive modulation such as 16-QAM, BPSK, QPSK and DPSK for AWGN channel is implemented and in indicated with the parameters such as Carrier frequency, Bandwidth of channel , Signal to Noise ratio to increases the data rate and lower doppler frequency at different distances. The proposed adaptive modulation and to estimate the gain of channel paths . a method called compressed sensing technique was used. Methodology adopted through Matlab Simulation tool. From the simulation results, the BER values are computed for various adaptive modulation techniques at 10Kms, 30Kms and 50Kms distances and compared with them and validated the channel estimation result with the conventional algorithms.

Performance Analysis of Modulation Formats for Next Generation RoF Systems

Radio over fiber (RoF) has found to be one of the most effective communication techniques. It has the tendency to incorporate both optical fiber and free space radio paths. In this research article, importance, benefits, and applications of RoF system are discussed in detail for futuristic networks. The performance of RoF system is visualized by modulating the data with the RF signal having same frequency at both transmitter and receiver ends. Initially, the performance is checked using non-return to zero (NRZ) format and later compared with duobinary (DB) and carrier suppressed return to zero (CSRZ). Various simulations are performed which directly affect the system performance. Important parameters such as RoF link distance, data rate, transmitter power, amplifier gain, and RF signal frequency are tested. The operation is carried out at 1550 nm wavelength and 30 GHz RF frequency. System is optimized to receive the transmitted waveforms successfully. Simulations are performed in Optisystem 17.0 and MATLAB. For the analysis, the results are plotted using Q-factor and BER values.

Analysis of BER for optical transmission link using commercial fibers with and without dispersion compensation

In this paper, an optical transmission link at 10 Gb/s is experimented with Non -Return to -Zero (NRZ) modulated input source with the help of OptSim-software. The performance of the system has been measured in terms of BER for optical link developed using various types-of-fibers at reference loss and wavelength of 1550 nm along with dispersion and nonlinearities whose tolerances have been assessed up to 400 kms. Results have been obtained and compared by considering the impact of second and third order dispersion terms with and without dispersion compensation for different fibers. It has been observed that DS_Anomalous (DSA) fiber shows the best practical results with 10‒10 BER value at 246 kms of transmission -distance without dispersion compensation and 340 kms with dispersion compensation.

Simulative Comprehensive Analysis of 2D Algebraically Constructed Codes for Optical CDMA

In this manuscript, comprehensive analysis of distinct optical codes belonging to family of algebraically constructed codes has been demonstrated. Many optical codes belonging to algebraically constructed family such as Extended Reed-solomon codes (E-RS), Multi-level prime codes (MPC), Extended-multi level prime codes (E-MPC), and Variable-weight quadratic congruence codes (VWQCC), Bipolar/Unipolar codes are taken into consideration. The performance characteristics of these codes are examined through Hard-error limiting probability (HEP) equations. Investigations revealed that Bipolar/Unipolar code is the one algebraically developed code that has outperformed all the codes considered here even in the presence of Multi-user interference effect. It has been observed that this optical 2D Bipolar/Unipolar code shows minimum BER value with increasing user count. Hence Bipolar/Unipolar code is robust to multiple user interference affected OCDMA systems.

The Analysis of the Effect and Reduction of Carrier Frequency Offset in Orthogonal Frequency Division Multiplexing (OFDM) Multiple Input Multiple Output (MIMO)

Abstract— The development of cellular telecommunication provides users to experience fast and stable transmission. This standard of transmission is proportional to the needs of the devices and systems used. We are currently in the fourth generation (4G) of cellular technology. The key technologies used in 4G are Orthogonal Frequency Division Multiplexing (OFDM) which uses the concept of orthogonality for bandwidth efficiency and Multiple Input Multiple Output (MIMO) which uses the concept of diversity to improve performance. But in implementation this system will have problems with the transmission channel. The problem that occurs is signal attenuation due to Carrier Frequency Offset (CFO). This CFO will cause the orthogonal character built from the OFDM system to experience a decline in performance. The decline in performance is due to the occurrence of Intercarrier Interference (ICI). To overcome this problem, the method used in this simulation are Improved Sinc Power Pulse (ISP) and Rectangular Pulse (REC). The results showed that ISP had a relatively better BER value than REC and without using the pulse shaping method. The minimum BER value obtained from the simulation is ISP with a value of 0.0001 while REC produces a value of 0.0006 and without pulse shaping produces a BER value of 0.0038.

Development of a secured optical code-division multiple access system by implementing hybrid 2D-modified Walsh code

We present the development of a multi-user cross-layer security network implemented on the optical code-division multiple access (OCDMA) with newly designed hybrid 2D-modified Walsh code (MWC) along with an algorithmic approach in cryptography domain. Minimum BER value is evaluated on the order of 10 − 50 using our designed MWC, which is comparatively lower than other existing codes. The security performance of the network was analyzed using the probability detection parameter, which was found to be superior apart from few other available existing codes. The enhancement of the quality and grade of security in this network eavesdropper can intercept the designed optical code of OCDMA in the physical layer. It compels one to break the security in the data-layer to access the original code. We also calculated the probability of successful data interception as a function of time complexity. Furthermore, we presented the simulation of the hybrid system using the OptiSystem simulator.

A novel multi-granularity two-layer SDM ROADM architecture

In this paper, we study the multi-granularity switching of SDM optical network. We design and demonstrate a novel multi-granularity SDM ROADM. The optical node is a simple two-layer architecture, which has the functions of all-optical multi-granularity switching, business convergence, traffic grooming, channel add/drop and online monitoring. We demonstrate MCF-level switching, fiber-level granularity and wavelength-level granularity business convergence. Experimental results show that the average transmission loss value, crosstalk value and BER value are −40 dB, −10.5 dB and 10−10, respectively. There are four MCF-level entrances/exits in the experimental setup, each entrance/exit contains three fiber channels, and each fiber channel contains four wavelength channels with 10Gbps bitrate.

Digital back propagation based on the feedback-convergence for fiber nonlinearity compensation with low computational complexity and high performance

In this paper, an improved digital back propagation (DBP) method is proposed for the compensation of fiber non-linearity, which is based on the feedback-convergence assisted split-step Fourier method. The algorithm has been experimentally verified in a 1000 km 80 Gbit/s PDM-16QAM system. By optimizing the structure of nonlinear convergence within the DBP method, the accuracy of nonlinear compensation is improved comparing with the traditional algorithms while complexity reduced. The results show that the OSNR penalty for BER of HD-FEC threshold has reduced by 1.1 dB, and the transmission distance can be increased by ∼155 km for the threshold value of BER=1×10−4 compared to the traditional DBP method. When OSNR = 26 dB, the complexity of FC-DBP decreases 36.91% comparing with the traditional DBP method.

Performance Analysis of Visible Light Communication (Vlc) with and Without Consider the External Noise Using Mach Zehnder (Mz) Modulator

Visible light communication is a high-speed developing technique with LEDs for both lighting and data communication. In this paper, examined the visible light communication performance over Mach Zehnder Modulation via Optisystem simulation tool. Quality factor and BER values of different link distance are predicted by optisystem simulation tool. The planned system can support 5 Gbps data rate up to 50 meter of link distance with a Quality factor of 15.71 for without any external noise interruption. In the case of external noise influence, the planned VLC system performance is also investigated through simulation tool. Consider the external noise interruption, the designed system can support 2Gbps data rate up to 20-meter link distance of Quality factor of 11.935. Quality factor for the system without any external noise influence is better compared to the system with external noise influence.

Mitochondrial base excision repair positively correlates with longevity in the liver and heart of mammals.

Damage to DNA is especially important for aging. High DNA repair could contribute, in principle, to lower such damage in long-lived species. However, previous studies showed that repair of endogenous damage to nuclear DNA (base excision repair, BER) is negatively or not correlated with mammalian longevity. However, we hypothesize here that mitochondrial, instead of nuclear, BER is higher in long-lived than in short-lived mammals. We have thus measured activities and/or protein levels of various BER enzymes including DNA glycosylases, NTHL1 and NEIL2, and the APE endonuclease both in total and mitochondrial liver and heart fractions from up to eight mammalian species differing by 13-fold in longevity. Our results show, for the first time, a positive correlation between (mitochondrial) BER and mammalian longevity. This suggests that the low steady-state oxidative damage in mitochondrial DNA of long-lived species would be due to both their lower mitochondrial ROS generation and their higher mitochondrial BER. Long-lived mammals do not need to continuously maintain high nuclear BER levels because they release less mitROS to the cytosol. This can be the reason why they tend to show lower nuclear BER values. The higher mitochondrial BER of long-lived mammals contributes to their superior longevity, agrees with the updated version of the mitochondrial free radical theory of aging, and indicates the special relevance of mitochondria and mitROS for aging.

Speech watermarking robust against recapturing and de-synchronization attacks

Watermarking is a solution for forensics tracking for digital speech signal, while recapturing and de-synchronization attacks may remove the watermark effectively. It brings threat to watermarking technology used for forensics tracking. In this regards, we defined the discrete cosine transform coefficients logarithm mean (DCT-CLM) feature of speech signal and concluded that the interference caused by recapturing attack has similar impact on the DCT-CLM feature of two adjacent segments. Based on the feature, we proposed a speech watermarking method robust against recapturing and de-synchronization attacks. For the mute parts of speech signal have no meaning and are not the major component for forensics tracking, we focused on non-silence (NS) parts in this paper and embed watermark into DCT-CLM feature belonging to these parts. Compared with the state-of-the-art works, the BER value of the proposed method is decreased by 9% for recapturing attack. Besides, the method outperforms the recent robust watermarking methods notably for recapturing and post-processed with signal processing operations and de-synchronization attacks.

Space-time code selection via particle swarm optimization

In this paper, the space-time code selection technique for multiple-inputs single-output systems is optimized using particle swarm optimization. We considered both variable-rate and constant-rate strategies. For a variable-rate technique, we address the problems of minimizing the bit-error rate for a given throughput objective and maximizing the throughput for a given bit-error rate objective. For a constant-rate technique, we address the problem of minimizing the bit-error rate. Results show that it is possible to find BER and throughput values close to those required when using a variable-rate technique with optimized threshold levels. For the constant-rate technique, we obtain considerable energy to noise gains when using optimized threshold levels.

Raman amplifier performance in pre-amplifier use for optical fiber communication systems

The development of telecommunications networks is currently dominated by fiber optics. The fiber optic has become a waveguide medium transmitting information with high frequency bands, high capacity and high speed. An optical amplifier is required to maintain electromagnetic signals when they propagate in far distance. One of the amplifiers, Fiber Raman Amplifiers (FRA) which is the light scattering from the light that comes with the phonon in the lattice of amplification medium produces photons that are coherent with the incoming photons. Many amplifiers are commonly used but the problems not only come from the amplifier but also the component circuit and system. By simulation method, FRA circuit is designed and operated in the form of pre-amplifiers to maintain a better signal from material interference and geometry. The simulation results show that the lowest BER value and the highest Q-factor are found at a distance of 10km depicted by eye diagram.

Desain JaringaniFiberiToiThe HomeiTeknologiiGigabit Passive Optical Network (Gpon) Menggunakan Optisystem Untuk Area Sukawati

A Planning for fiber optic network using optical simulation from STO to ONT (optical Network Termination) with the farthest distance of ± 6.22 km done in the area of Jl. Batuyang, Kangin Batubulan, Sukawati, with an estimated number of customers of 270 customers aiming to switch networks from Multi Services Access Network (MSAN) to Gigabit Passive Optical Network (GPON). Planning starts from the survey area that will be built by the network, determines the customer's estimation, estimates the placement of the device and determines the specifications of the device to be used. Planning starting from STO to ONT / customer uses an optical application which will result from planning in the form of PRx on ODP (Optical Distribution Pack), PRx on ONT and bit error rate. The results of the analysis carried out, the Rx power generated in the ODP with the farthest distance of ± 6.22 km, which is for measuring results -26,893 dBm while in the planning results can be as much as -22,744 dBm, and PRx in ONT obtained for measuring results while in the planning obtained a result of -24.722 dBm, from the PRx results obtained the attenuation value is still below the ITU-T G.984 standard which is -28 dBm. BER value (Bit Error Rate) that is produced with the farthest distance of ± 6.12 km is 3,33x10?19 bit/s, this value is below the standard, namely 10?9 bit/s, with this result, optical fiber network planning using an optical system is feasible.

Görünür Işık Haberleşmesi için Çift Dördün Uzaysal Yoğunluk Modülasyonu

In this paper, a new spectrally efficient space modulation technique, which is called double quadrature spatial intensity modulation (DQSIM), is proposed for multiple-input multiple-output (MIMO) visible light communication (VLC) systems. Sub-carrier intensity modulation (SIM), which ensures the use of in-phase/quadrature (I/Q) signals in intensity modulation direct detection (IM/DD) systems, is used as a digital modulation scheme. In RF, quadrature spatial modulation (QSM) transmits the I/Q signals through single or multiple antennas selected independently from each other. Furthermore, the orthogonality between I and Q components is provided for the half period of sinusoids. DQSIM utilizes these two features and transmits four fold more bits than spatial modulation (SM) via spatial constellation. SIM uses two-fold bandwidth compared to on-off keying (OOK), while DQSIM uses three fold. DQSIM outperforms benchmark modulation schemes, which are SIM-SM and PAM-SM, at the BER value of 10 -4 . Furthermore, DQSIM performance has increased with increasing number of LEDs.

The Usage of Time Reverse Technology to Improve The BER Performance and Transmission Rate of IR-UWB System

Ultra-Wideband (UWB) technology has so many striking characteristics which includes low sensitivity to fading, superior performance, low interference, easy to penetrate in walls as well as in floor. The main motive of this work is to analyze the capability of UWB technology as various aspects and improve its performance, since the main drawback of this system is that the power spectral density of the transmitted signal is rather limited. The MIMO technology may provide a solution by increasing the received SNR for the same transmission power, but the problem in this case is the spatial correlation resulted. To solve the problem two technologies are integrated along with the UWB using Time Reverse (TR) by TR-MIMO and TR-SIMO. Among these integrations, the robust performance of the UWB is analyzed by comparing the transmission rates for a given outage probability. In the last step, the (SIMO/MIMO)-UWB and TR-(SIMO/MIMO)-UWB were compared in terms of BER values to create the way of applying the UWB in so many applications.