High BER Research Articles

A high speed and low BER dual-mode adaptive equalizer using hybrid parallel DFE

A high speed and low BER dual-mode adaptive equalizer using hybrid parallel DFE

PAPR and BER Analysis in FBMC/OQAM System with Pulse Shaping Filters and Various PAPR Minimization Methods

Filter Bank Multicarrier with Offset Quadrature Amplitude Modulation(FBMC/OQAM) system design based on frequency sampling prototype filter takes into account the low frequency utilization of Orthogonal Frequency Division Multiplexing(OFDM) caused by adding Cyclic Prefix(CP). The CP decreases spectral efficiency and increases Peak to Average Power Ratio(PAPR). FBMC is an OFDM enhancement. In this paper to reduce the PAPR, we explained companding methods. We have proposed an FBMC that makes use of prototype pulse shaping filters which can be adjusted to meet system requirements in order to defeat these limitations. Due to its significant effect on the performance of FBMC-OQAM, choosing the right filter is crucial. Different prototype filters are used to investigate the performance of the FBMC-OQAM in this paper. Using the validated system, it was found that frequency utilization is more and good out-band suppression as well as an excellent application value in 5G technology. By using ?-law companding method, FBMC/OQAM provides better performance. It produces low PAPR, low out of band(OoB), high BER performance, less computational complexity and high spectral efficiency as compared to other methods.

THE PERFORMANCE COMPARISON OF RF LEVEL MULTIPLEXING AND OPTICAL LEVEL MULTIPLEXING IN RADIO OVER FIBER SYSTEMS WITH DIRECT OPTICAL MODULATION TECHNIQUES

Communication in the world is developing very rapidly, not only limited to voice but data communication. Many techniques have been used to support multimedia services. Radio over Fiber is expected to support communication for long distances. Therefore, a Comparison of Performance Analysis was carried out using optisystem. Radio over Fiber is simulated by radio frequency signals of 10 GHz and 15 GHz. Radio over Fiber technology for long-distance communication is very vulnerable to high BER and attenuation values, so it requires a mature system design and adequate equipment specifications.

Quantum encryption in phase space with displacement operators

In photonic computing, the quantum systems consist of coherent states and squeezed coherent states. Common quantum gates found in these systems are: phase shift, displacement, and squeezing gates. These gates are all unitary and reversible. Outside of quantum systems, coherent states also plays a significant role in coherent optical communications with speeds of hundreds of gigabits per second. Secure optical communications is generally implemented at the data layer with classical symmetric encryption such as Advanced Standard Encryption or AES. This inevitably allows any wiretapping to capture the transmitted data either in the plaintext mode or in the encrypted ciphertext mode in the optical infrastructure. The recent and rapid developments in Quantum computing further lift up the need for quantum secure communications in the optical infrastructure. This paper proposes a novel quantum encryption in the coherent optical domain utilizing a displacement operator and implementing with IQ-MZM optical modules, called Quantum Encryption in Phase Space or QEPS. The communication peers share a secret used to seed cryptographic pseudo random number generators to produce a synchronized random number at both the transmitter and receiver. The synchronized random numbers are used to establish displacement operators to encrypt the coherent states at the transmission and decrypt the cipher coherent states at the receiver. Therefore, malicious parties tapping along the fibre line would not extract the message in transit from optical domain due to a high Bit Error Rate or BER. The optimal displacement operator is split into a standard 16-QAM and a random phase shift operator to enhance the transmission security. We analysis the transmission security with the wiretap channel model for semantic security. We have simulated the QEPS encryption and decryption for two data modulation schemes: QPSK and 16-QAM over 80 km for transmission speeds of 56 Gbps for QPSK and 112 Gbps for 16-QAM.

A 28 nm 512 Kb adjacent 2T2R RRAM PUF with interleaved cell mirroring and self-adaptive splitting for high density and low BER cryptographic key in IoT devices

This paper elaborates a 2-transistor -2-resistor (2T2R) RRAM PUF scheme with assisting circuit techniques for dense and reliable cryptographic key generation and storage. The set time mismatch in two adjacent RRAM devices is utilized to enhance the tolerance of PUF output for against PVTA variations. Array architecture with interleaved cell mirroring further improves the randomness by eliminating the systematic deviation. Self-adaptive write with current limiter eliminates the negative effect of mismatch in the peripheral circuits and suppresses the undue duration of large operation current. Double-ended differential sensing brings robustness against side-channel attacks and less voltage stress on RRAM cells. Silicon data from a 512 Kb RRAM PUF test chip in 28 nm technology demonstrates our PUF passes NIST test with intra-chip Hamming distance (HD) of <10−5 and inter-chip HD of 0.496, and the BER is < 10−5 from 0 to 120 °C. The proposed PUF also supports reconfigurability with good randomness and improved efficiency, featuring good resilience against machine learning attacks.

Mine MIMO Depth Receiver: An Intelligent Receiving Model Based on Densely Connected Convolutional Networks.

Multiple-input multiple-output (MIMO) systems suffer from high BER in the mining environment. In this paper, the mine MIMO depth receiver model is proposed. The model uses densely connected convolutional networks for feature extraction and constructs multiple binary classifiers to recover the original information. Compared with conventional MIMO receivers, the model has no error accumulation caused by processes such as decoding and demodulation. The experimental results show that the model has better performance than conventional decoding methods under different modulation codes and variations in the number of transmitting terminals. Furthermore, we demonstrate that the model can still achieve effective decoding and recover the original information with some data loss at the receiver.

SINR and Capacity Analysis for Multiuser MIMO Interference Channels

Multiple-Input-Multiple-Output (MIMO) has a significant effect on wireless communications due to providing high capacity and low BER as compared to the conventional wireless communications with SISO. Due to transmitting a large number of an independent signal from different users in different space-time approach, the BER performance suffers inferiority leading to decreasing in the system reliability. So, our work is based on maximizing the SINR of a multiuser (MU)-MIMO system by sending separate data of different users from one base station (BS) via a number of antennas with different time slots to a number of mobile stations (MS) each with more than one antenna technique. The proposed work considers one user as a desired user and others as interferer users when these data are propagating in multipath fading channel. BER performance as well as channel capacity for various diversity systems such as 2×2 and 4×4 are simulated. The numerical results obtained by computer simulation show that implementing 4×4 MIMO system gives gain of 1 dB as compared to the system implemented with 2×2 MIMO. The results show that when the 10 users communicate with the BS required SINR of 18 dB at 10−2 BER while for 20 users it requires a SINR of 20 dB at BER of 10−2. We can conclude that the BER is decreased and the capacity is increased with increasing the number of antennas when the system is under multiuser and multipath interferences.

V-Band Six-Port Interferometer Receiver: High Data-Rate Wireless Applications, BER and EVM Analysis, and CFO Compensation

V-Band Six-Port Interferometer Receiver: High Data-Rate Wireless Applications, BER and EVM Analysis, and CFO Compensation

PCI Express 6.0 Specification: A Low-Latency, High-Bandwidth, High-Reliability, and Cost-Effective Interconnect With 64.0 GT/s PAM-4 Signaling

PCI Express (PCIe) specification has been doubling the data rate every generation in a backward compatible manner every two to three years. PCIe 6.0 specification will adopt PAM-4 signaling at 64.0 GT/s for maintaining the same channel reach of prior generations. A forward error correction (FEC) mechanism will offset the high BER of PAM-4. We propose a new flit-based approach with a lightweight, low-latency FEC coupled with a strong cyclic redundancy check (CRC) and a low-latency link-level retry mechanism to meet the stringent low-latency, high-bandwidth, and high-reliability goals. We also present a new low-power state that ensures power consumption is proportional to bandwidth usage without impacting the traffic flow.

Performance Analysis of Efficient and Low Complexity MIMO-OFDM System Using Modified V-BLAST

Background and Objective: To analyze the performance of MIMO-OFDM system, VBLAST detection suffers from computational complexity as well as high BER. Methods: To improve the BER performance and to reduce the computational complexity of receiver, we propose a modified VBLAST detection in MIMO-OFDM Systems. Results: Simulation using MATLAB shows the improvement in computational complexity and in BER. Conclusion: This modified VBLAST reduces the complexity of MIMO-OFDM System to 44.2% and improvement in BER as compared to conventional VBLAST based MIMO-OFDM System.

The efficient interleaving of digital-video-broadcasting-satellite 2nd generations system

The DVB-S2 system is designed as a toolbox to permit the execution of the satellite programs. Interleaver is an essential part of the DVB-S2 system. The current general block interleaver in DVB-S2 is not best, which leads to high BER and maybe not satisfy the requirements of the system. The purpose of this paper is to study the several interleaver types and comparative analyses are done between them to find which of these give better performance. Simulations results obtained prove that the 2D interleavers minimize BER more than other interleavers of DVB-S2. Further, the performance of 2D interleaver is better on a system that required a low SNR.

Scalar Feedback-Based Joint Time-Frequency Precoder Interpolation for MIMO-OFDM Systems

In MIMO-OFDM systems, knowledge of the precoding matrix enables effective resource allocation for high rates and low BER. However, feeding back precoders for all subcarriers introduces large overheads. Past work has shown that the orthonormal structure of the precoder enables effective parameterization and quantization using Givens rotations and Householder transformations. Also, the use of temporal and frequency correlations can further reduce the feedback requirements. We present a framework that utilizes adaptive feedback with joint time-frequency prediction for precoder construction at the transmitter. Simulations reveal that the proposed method achieves significantly lower BERs for various channel profiles compared to other approaches.

SoftMax Recurrent Neural Network based Faded Channel Estimation using FIM in MIMO-OFDM

The combination of MIMO technology with OFDM system, there is enhancement of wireless digital communication which is quite beneficial for future communicating system. MIMO-OFDM improves the efficiency and quality of the wireless scenario. With efficient channel estimation technique especially non-blind under MIMO-OFDM scenario present an enhanced performance with low complexity. In the pilot type, the least squares method (LS method) is less complex and requires an implicit knowledge of the channels. However, it suffers from inter-carrier interference (ICI). For this reason, the optimal design of Channel Estimator is an area of ongoing research. In this work, the performance of the DWT-OFDM scheme in combination with a multi-input system and multiple outputs for unknown pilot symbols is evaluated using a neural network. Take advantage of time series prediction using a recurrent neural network (RNN) with a SoftMax layer with frequency index modulation to perform channel prediction. In this research work a comparative analysis is performed among proposed softmax recurrent neural network based channel estimation with existing channel estimation technique for variable signal to noise ratio (Eb/No) for frequency indexed modulation techniques. The existing channel estimation techniques for MIMO-OFDM communicating environment are based on known pilots over the noisy fading wireless environment. From simulation result, it is observed and concluded that the existing channel estimation techniques gives higher BER as compared to proposed softmax recurrent neural network channel estimation technique.

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.

The Combined Therapy of Berberine Treatment with lncRNA BACE1-AS Depletion Attenuates Aβ25-35 Induced Neuronal Injury Through Regulating the Expression of miR-132-3p in Neuronal Cells.

Accumulating articles reported that berberine (Ber) played a neuroprotective role in Alzheimer's disease (AD). Long noncoding RNAs (lncRNAs) have been identified as biomarkers and therapeutic targets of AD. However, the precise mechanism by which lncRNA β-amyloid cleaving enzyme 1 antisense RNA (BACE1-AS)regulates the progression of AD remains largely unknown. HPN and SK-N-SH cells treated with amyloid β 25-35 (Aβ25-35) were regarded as AD model in vitro. Cell survival rate was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Lactate dehydrogenase (LDH) cytotoxicity assay was conducted to detect the cytotoxicity of neuronal cells. Flow cytometry was performed to determine the intracellular concentration of Ca2+, reactive oxygen species (ROS) and apoptosis of neuronal cells. Western blot assay was carried out to detect the apoptosis-related proteins of neuronal cells. The abundance of lncRNA BACE1-AS and miR-132-3p was measured by quantitative real time polymerase chain reaction (qRT-PCR). The binding sites between miR-132-3p and BACE1-AS were predicted by Starbase, and the combination was confirmed by dual-luciferase reporter assay. We found that Ber alleviated Aβ25-35 induced neuronal injury in AD model, especially in high concentration Ber group. The enrichment of BACE1-AS was positively regulated by Aβ25-35 and was inversely modulated by Ber in neuronal cells. The interference of BACE1-AS alleviated the neuronal damage of AD model. miR-132-3p was a direct target of lncRNA BACE1-AS in HEK293T cells, and it was negatively regulated by BACE1-AS in neuronal cells. BACE1-AS accumulation reversed the protective effect of miR-132-3p overexpression on AD model. Ber treatment and BACE1-AS intervention recovered the viability of AD model. Ber up-regulated the level of miR-132-3p via BACE1-AS in SK-N-SH and HPN neuronal cells. in conclucsion, Ber protected neuronal cells against Aβ25-35 at least partly through BACE1-AS/miR-132-3p axis. The combined therapy of Ber treatment with BACE1-AS depletion might provide new insight into AD treatment.

Spectral Efficiency of FBMC Over OFDM System

Significant wireless broadband technology used in various cellular standards is Orthogonal Frequency Division Multiplexing (OFDM) which will make use of Multi Carrier Modulated (MCM) systems. Even though OFDM has numerous advantages, it is hard to employ OFDM for complex networks. It is very hard to establish synchronization in mobile environments as it is difficult to predict the Doppler shifts of different users, which results in inter carrier interference (ICI). Further, filters associated with OFDM carrier have comparatively large sidebands which outcomes in Out of Band (OOB) radiations. Insufficient spectral usage is provided by CP-OFDM by using more guard band. So the problems caused by traditional OFDM/CP-OFDM can be answered by employing a new system termed as Filter Bank Multi Carrier (FBMC) System. It is a form of MCM and it can be considered as an advanced cyclic-prefix (CP-OFDM). In OFDM, whole band gets filtered while in FBMC, each sub carrier band is independently filtered. The primary objective of this work is to relate the performance of 5G modulation technique such as FBMC against OFDM and to suggest an ideal waveform for 5G communication in regard to high spectral efficiency, spectral density, BER and less Peak to Average Power Ratio (PAPR).

Performance Improvement of FTTH Architecture with OCDMA Technique

In proposed simulation model, Fiber to the home (FTTH) architecture with a filter called fiber Bragg grating (FBG) based the optical code division multiple access (OCDMA) technique used to provide access to number of users to share all the bandwidth simultaneously. FTTH provides higher bandwidth than the traditional existing technology of broadband, having the capability of providing all the servixces of communication like data services, voice services and video services. The traditional metallic cables are replaced with optical fibers in Fiber to the Home to end line consumers. OCDMA provides high reliable communication. The performance improvement of FTTH architecture is done through OCDMA technique. In paper at very first, FTTH, the system with OCDMA is explained after that the architecture of FTTH using OCDMA technique, its principle explained. The proper coordination of time plays an important role in OCDMA, otherwise there is more chances of overlapping of signals and noise which may some time lead to crosstalk. There is a use of FBG as an encoder and decoder because of its low cost and the investigation is done on eye opening, BER, Q factor. The proposed model provides high Q-factor and minimum BER which is required for demands of the future communication services.

Interference Cancellation for Underwater Environment

In this paper, Performance of MIMO-OFDM systems in underwater wireless optical communication are studied. The execution of MIMO underwater environment regulation is examined. To alleviate turbulence induced fading, spatial diversity over underwater environment link is used. Furthermore, scattering and absorption are considered in the analysis. Analytical BER computations are fundamentally the same as simulated results. Interference cancellation inclusion in OFDM system has better BER performance than conventional method. So, by IC can accomplish high BER productivity than conventional system. Moreover, simulated results demonstrate that OFDM using IC plot has better BER execution for underwater environment.

Rprop and improved Rprop+ based constant modulus type (RCMT) blind channel equalization algorithm for QAM signal

The aim of paper is to address the issues such as poor convergence, moderate BER, residual ISI associated with unsupervised (blind) weight adaptation technique employed for channel equalization. Two noble algorithms based on resilient back propagation framework have been proposed as solution for QAM signal. The widely accepted gradient descent based Constant Modulus algorithm suffers from poor convergence issues, high residual ISI and Moderate BER. Proposed solution assimilate Constant Modulus Algorithm (CMA) like error function into a general Rprop algorithm having two distinctive approaches of with/ without weight backtracking capability, taking into consideration of frequency selective nature of channels and additive gaussian noise. The algorithms exploit the advantage of Rprop mechanism, thus improving the convergence rate and have better ISI (inter symbol interference) suppression capability. Simulation of the proposed Rprop and improved Rprop+ based CM type (RCMT) algorithm proves their advantageously enhanced capabilities in terms of convergence, complexity, and residual ISI in comparison to the CMA and its variants. Proposed algorithm can also been used for M-PSK signal for which it shows similar performance.

An Improved Blind Recognition Algorithm of Frame Parameters Based on Self-Correlation

The blind recognition of the frame parameter plays a crucial role in frame synchronization in the background of a non-cooperation communication system. This paper proposes an algorithm based on self-correlation on the foundation of existed cumulative filtering algorithm. To overcome high BER, the peak-to-average ratio (PAR) is calculated to improve the algorithm. The simulation results proved that the performance of the algorithm has been improved.