Bit Error Rate Analysis Research Articles

Construction and performance analysis of variable-weight optical orthogonal codes for asynchronous OCDMA systems

A construction scheme of variable-weight optical orthogonal codes (VW-OOCs) for asynchronous optical code division multiple access (OCDMA) system is proposed. According to the actual situation, the code family can be obtained by programming in Matlab with the given code weight and corresponding capacity. The formula of bit error rate (BER) is derived by taking account of the effects of shot noise, avalanche photodiode (APD) bulk, thermal noise and surface leakage currents. The OCDMA system with the VW-OOCs is designed and improved. The study shows that the VW-OOCs have excellent performance of BER. Despite of coming from the same code family or not, the codes with larger weight have lower BER compared with the other codes in the same conditions. By taking simulation, the conclusion is consistent with the analysis of BER in theory. And the ideal eye diagrams are obtained by the optical hard limiter.

FPGA based Multichannel Bit Error Rate Tester for Spacecraft Data Acquisition System

Bit Error Rate (BER) is a principle measure of data transmission link performance. BER tester (BERT) consists of a Pattern Generator and an Analyzer that can be set to the same pattern. The payload data transmitted from the spacecraft consists of one, two or three channels per carrier based on the modulation scheme. The traditional equipments can do BER analysis for only one channel at a time. In order to support multichannel BER analysis, a Personal Computer (PC) based system is designed and implemented in Altera Stratix II (EP2S130F1508C5N) FPGA. Ethernet is configured using WIZnet 5300 (Ethernet Controller) and it is used for communication between FPGA and PC with an application. Application is used to transmit the Pattern Generator’s configurations from PC to FPGA and to receive Analyzer’s status. Packet processing is done for this communication using User Datagram protocol (UDP). On the whole, traditional equipments are replaced by the designed and implemented bit error rate tester.

Single laser free-space duplex communication system with adaptive threshold technique and BER analysis in weak turbulent atmosphere.

A free space duplex communication system with a single laser and a modulated retro-reflector is presented. A method to minimize the echo wave bit error rate (BER) of this system is proposed by setting the optimum threshold automatically based on the measured mean power and irradiance variances with log-normal distribution and the Bayes minimum classification error criterion. Experiments were taken at a distance of 1.55 km in a weak turbulence and the measured BER was 0.0213. The BER performance of this system is studied and the result shows the experimental BER is in good accordance with the theoretical value.

Efficient time gating in ultrafast optical TDM networks

Ultrafast optical communication is the backbone of high-speed global networking infrastructure. Optical time division multiplexing (OTDM) is a popular technique for embedding data from many simultaneous users on a single optical channel. This paper studies the optimal clock signal used in optical time gating to extract the data of the desired user in an OTDM network. We show that the pulse width of the clock signal can be optimized to achieve a minimum bit error rate (BER) in these networks. In this paper, we assume that the optical clock signal used for time gating has jitter, and there is therefore a delay variation between the clock and data signals. We model this delay as a zero mean Gaussian random variable. Using this model, an analytical BER expression is derived for systems with Gaussian pulses. In the numerical results, we find the optimal values of the clock pulse width by evaluating the BER versus the pulse width for different variances of the delay. Simulation results are also presented to evaluate the accuracy of the analytical expression.

Interaction between Symbol Timing Offset and Channel Interpolation in OFDM Systems: BER Analysis and Performance Degradation

In orthogonal frequency division multiplexing (OFDM) systems, since the cyclic prefix (CP) is designed to be longer than the channel impulse response, there exists a certain range within the CP where symbol timing synchronization can be accomplished avoiding adjacent inter symbol interference. However, the appearance of a linear phase term across subcarriers in the frequency-domain due to symbol timing offset (STO) is known to affect the performance of channel interpolation. In this paper, we analyze the performance degradation due to the interaction between STO and channel interpolation in OFDM systems affected by multipath Rayleigh fading. Particularly, simple closed-form expressions for the bit error rate (BER) are obtained for different quadrature amplitude modulation constellations. Results show that there exists an irreducible BER floor due to STO and channel interpolation, which depends on the STO, the subcarrier index, the pilot spacing and the correlation between pilot subcarriers.

Indoor optical wireless MIMO-OFDM system

Indoor optical wireless systems have attracted attention, because they allow high-speed transmission without electromagnetic interference. Multi Input Multi Output (MIMO) techniques are very promising in providing high data rate or providing performance over fading channels. Orthogonal frequency division multiplexing (OFDM) can send multiple high speed signals by using orthogonal carrier frequencies. In this paper, we propose an optical wireless MIMO-OFDM system to achieve better performance. The signal of each optical transmit antenna is detected by using zero forcing (ZF) algorithm. We use the error vector magnitude (EVM) to predict BER performance. The analysis of bit error rate (BER) shows that the proposed system achieve better performance transmission than OMIMO system when transmitting the signal over reflection channels.

PERFORMANCE ANALYSIS OF DWDM BASED FIBER OPTIC COMMUNICATION WITH DIFFERENT MODULATION SCHEMES AND DISPERSION COMPENSATION FIBER

Dense Wavelength Division multiplexing (DWDM) is a novel technology that can improve the channel capacity and meet growing demands for bandwidth of the optical fiber communication system. This technology utilizes a composite optical signal carrying multiple information streams. Each information streams transmitted on a distinct optical wavelength onto a single fiber. The performance of DWDM is degraded by non-linear optical effects. They are Cross phase modulation (XPM), Self phase modulation (SPM), four wave mixing (FWM), stimulated brillouin scattering (SBS) and stimulated Raman scattering (SRS). In this paper we analyze the performance of Dense Wavelength Division Multiplexing (DWDM) based fiber optic communication system at different modulation schemes, various power level and different number of data channels. we use the dispersion compensation fiber along with single mode fiber (SMF) for length of 100km at 1550nm to reduce the dispersion of optical signal. The performance of improved detected signals has been evaluated by the analysis of Quality factor and bit error rate (BER). The simulation studies are carried out using optisystem software from optiwave.

BER analysis of space‐time coded RFID system in Nakagami‐ m fading channels

The exact bit error rate (BER) analysis of a space-time coded radio frequency identification (RFID) system is presented, where the tag has multiple antennas and the reader has a single antenna. In the analysis, the forward and backward channels exhibiting independent but not necessarily identically distributed Nakagami-m fading are considered, and the diversity order that the system can achieve is found to be Nmin(m h, m g), where N is the number of antennas at the tag and m h and m g are the fading parameters corresponding to the forward and backward channels, respectively. The analytical results are verified through comparison with the simulation results.

Cyclic Prefix Optimization of OFDM System

There are many methods to reduce the multipath effects in wireless communication. Multicarrier modulation for data transmission is one of the methods to overcome the effect of Inter Symbol Interference (ISI), also known as Orthogonal Frequency Division Multiplexing (OFDM). The analysis of Bit Error Rate (BER) performance suggests, OFDM is better than Code Division Multiple Access (CDMA) which is mostly incorporated in existing 3G systems.(1)In this article the influence of cyclic prefix and pilot insertion technique on an OFDM system is analyzed on an AWGN channel. The OFDM system is simulated with MATLAB programming as well as simulink model , and the BER curves with and without CP/PI are compared. The variance of power loss and information rate loss with length of the cyclic prefix is explained.

BER Performance of QPSK-Transmitted Signal for Power Line Communication under Nakagami-like Background Noise

Power line communication (PLC) technology is used in various areas of a smart grid. The extensive use of PLC technology has proved its key role in smart grids throughout the world. Despite PLC's advantages, it suffers from a difficulty in modeling and analysis of its power line channel. Many researchers have experimented and proposed channel models for their own defined environments; as a result, a unified model for the power line has not been presented. To overcome this problem partially, we used a Nakagami-m distribution like background noise and analyzed the performance of the binary transmission system in our previous work. In this paper, we compare the analytical and simulated BER (bit error rate) performances of QPSK (quadrature phase shift keying) transmission system with Gray encoding. We verify that the analyzed and simulated performances are well matched for different values of m.

BER analysis of IM/DD FSO system with APD receiver over gamma-gamma turbulence

In this paper, the bit-error rate (BER) performance of intensity modulated with direct detection (IM/DD) free space optical (FSO) system using the on-off keying (OOK) and avalanche photodiode (APD) receiver is analyzed. The intensity fluctuations of the received optical signal are modeled by gamma gamma distribution, while both zero and nonzero inner scale models are observed. The total receiver noise includes APD shot noise and thermal noise. The BER expression is theoretically derived and numerical results are presented. The results illustrate the BER dependence on the turbulence strength, propagation path length, APD gain and noise temperature.

Performance Analysis of Bit Error Rate in Full-Duplex Wireless Communications with Analog Cancellation Error

Recent work has shown the full duplex transmission scheme to allow nodes to send and receive in the same frequency at the same time. In this paper, we investigate the impact of analog cancellation error on the bit error rate (BER) performance of full duplex wireless communication system. Considering the transmission delay error, amplitude error and phase error of analog cancellation, we derive the analytic BER expression of binary phase shift keying (BPSK) in additive white Gaussian noise (AWGN) channel. The analysis results show that BER generally decreases with timing and amplitude error decreases for fixed signal to interference rate (SIR). Compared with the ideal analog cancellation system, the performance loss 0.3dB when the phase error is 0.0001 degree, carrier frequency is 800MHz and SIR is 100dB.

A General Framework for BER Analysis of OFDMA and Zero-Forcing Interleaved SC-FDMA over Nakagami-m Fading Channels with Arbitrary m

In this letter, bit error rate (BER) analysis is presented for both orthogonal frequency-division multiple access (OFDMA) and zero-forcing (ZF) interleaved single-carrier frequency-division multiple access (SC-FDMA) systems over Nakagami-m frequency-selective fading channels with arbitrary m. Specifically, the analytical BER is derived for both cases based on a general framework, that is by exploiting the statistics of the equalized noise. In comparison with the exiting alternatives, the proposed BER analysis has only half of the computational complexity for the OFDMA system and is more general for the SC-FDMA case.

Performance of Non-Adaptive and Adaptive Subcarrier Intensity Modulations in Gamma-Gamma Turbulence

We investigate a variable-rate, constant-power adaptive subcarrier intensity modulation employing M-ary phase shift keying and rectangular quadrature amplitude modulation for optical wireless communication over the Gamma-Gamma turbulence channels. The adaptive schemes offer efficient utilization of optical wireless communication channel capacity by adapting the modulation order according to the received signal-to-noise ratio and a pre-defined target bit-error rate requirement. Novel closed-form series solutions are presented for the achievable spectral efficiency, average bit-error rate, and outage probability using a series expansion approach of the modified Bessel function. In addition, asymptotic bit-error rate and outage probability analyses are presented. Our asymptotic bit-error rate analysis shows that the diversity order of both non-adaptive and adaptive systems depends only on the smaller channel parameter of the Gamma-Gamma turbulence. Numerical results demonstrate high accuracy of our series solutions with finite number of terms and improved spectral efficiency achieved by the adaptive systems without increasing the transmitter power or sacrificing bit-error rate requirements.

Jamming Rejection Using FFH/MFSK ML Receiver Over Fading Channels With the Presence of Timing and Frequency Offsets

The composite effect of hostile multitone jamming and partial-band noise jamming on bit-error rate (BER) performance of a fast frequency-hopped M-ary frequency-shift-keying system is studied over Rayleigh fading channels in the presence of timing and frequency offsets. The maximum-likelihood (ML) diversity-combining method is employed to improve BER performance of the system. Analytical BER expression of the proposed ML receiver is derived. The analytical results, validated by computer simulation, show that the proposed ML receiver can suppress the composite hostile jamming more effectively than some existing conventional diversity-combining receivers. The ML receiver is also found to be robust against inaccurate estimation of the required side information.

Spatial modulation over K multiplicative complex fading wireless channels

The authors apply spatial modulation over multiplicative complex fading wireless channels, where the multiplicative complex fading is represented by the product of K statistically independent and identically distributed standard complex Gaussian random variables, where K ≥ 2. The analytical bit-error rate (BER) approximation of symbol estimation is obtained in terms of a Meijer's G function. The conditional pairwise error probability (PEP) of transmit antenna index estimation is a function of a stochastic parameter with an unknown distribution function. The authors propose a lognormal distribution to approximate the distribution of this stochastic parameter. Based on the lognormal distribution, the average PEP and the analytical error probability upper bound of transmit antenna index estimation are derived. A goodness of fit test successfully validates the proposed lognormal distribution being the approximate distribution of the stochastic parameter. The derived analytical BER approximations for both symbol and transmit antenna index estimation are successfully validated via Monte Carlo simulations.

Differential Decoding of SIM DPSK over FSO MIMO Links

In this paper, we derive a differential decoder for the subcarrier intensity modulation (SIM) based differential phase shift keying (DPSK) scheme in free space optical (FSO) multiple-input multiple-output (MIMO) communication system. The proposed differential decoder avoids requirement of the knowledge of irradiance fluctuations in the receiver contrary to the existing selection combining (SC) based decoder of SIM DPSK. Moreover, the proposed differential decoder enables the SIM DPSK scheme to outperform the non-coherent decoding based pulse position modulation scheme. We theoretically analyze the bit error rate (BER) performance of the SIM differential binary phase shift keying modulation scheme with differential decoding over FSO MIMO links which follow the Gamma-Gamma distribution. On the basis of the analytical BER, the analytical diversity order of the proposed differential decoder is obtained.

수 Gbps 고속 인터페이스의 오류검출을 위한 자가내장측정법의 가속화 연구

본 논문에서는 고속 인터페이스 비트오류율(BER, Bit Error Rate)의 수학적 모델을 기반으로, 간단하고 정확하게 시간마진을 추정할 수 있는 '선형 근사화 추정법(linear approximation method)'을 제안하였다. 기존의 Q-factor를 이용한 추정법과 제안한 선형 근사화 추정법을 이용하여 <TEX>$10^{-13}$</TEX> 이하의 BER을 얻기 위한 시간마진을 추정한 결과는 실측한 값과 비교할 때 약 0.03UI 정도의 작은 오차를 갖는다. 이 중 선형 근사화를 이용한 가속 자가내장측정법(built-in self test)을 내부 BERT(BER Tester)를 포함한 하드웨어로 구현하였다. 3Gbps, 95% 신뢰 수준에서 <TEX>$10^{-13}$</TEX> BER 기준의 시간마진을 직접 측정하는데 소요되는 시간이 약 5.6시간인데 반해, 가속 자가내장측정법은 0.6초 이내에 유사한 정확도로 시간마진을 추정한다. 시간마진 추정치는 시간마진을 내부 BERT로 직접 측정한 값과 0.045UI 이하의 작은 오차를 보였다. In this paper, we propose a 'linear approximation method' which is an accelerated BER (Bit Error Rate) test method for high speed interfaces, based on an analytical BER model. Both the conventional 'Q-factor estimation method' and 'linear approximation method' can predict a timing margin for <TEX>$10^{-13}$</TEX> BER with an error of about 0.03UI. This linear approximation method is implemented on a hardware as an accelerated Built-In Self Test (BIST) with an internal BERT (BET Tester). While a direct measurement of a timing margin in a 3Gbps interface takes about 5.6 hours with <TEX>$10^{-13}$</TEX> BER requirement and 95% confidence level, the accelerated BIST estimates a timing margin within 0.6 second without a considerable loss of accuracy. The test results show that the error between the estimated timing margin and the timing margin from an actual measurement using the internal BERT is less than 0.045UI.

Characterization of Complex Optical Modulation Formats at 100 Gb/s and Beyond by Coherent Optical Sampling

Optical fiber communication systems are migrating toward the use of sophisticated, nonbinary, modulation formats. It is thus important to develop measurement techniques and solutions capable of unambiguously quantifying such signals and associated hardware. Although one can adapt certain techniques developed for wireless signal characterization, significant differences exist between optical and RF wireless implementations of advanced modulation formats. To meet this measurement demand we present a method for characterizing high symbol rate multilevel modulation optical signals with high fidelity, based on coherent optical sampling, as a complement to the standard real-time electrical sampling approach. The technique enables constellation- and waveform monitoring, bit-error rate and error-vector magnitude analysis, which makes it suitable for transmitter characterization.

Performance of carrier phase recovery for electronically dispersion compensated coherent systems

An analytical approach taking into account carrier phase estimation (CPE) is presented to predict performance of quadrature phase shift-keying (QPSK) systems using coherent detection. Using this approach, system performance is found as a function of symbol rate, local oscillator (LO) linewidth, chromatic dispersion (CD) and signal-to-noise ratio (SNR). A new expression is derived for the covariance matrix of the conditional probability density function (pdf) of the decision statistic. This pdf is used to find bit error rate (BER) semi-analytically. Our analytical derivation assumes perfect removal of data modulation which corresponds to an ideal decision feedback (DF) carrier recovery. The validity of the analytical pdf for predicting BER is verified for a wide range of system parameters of interest in long haul systems. In addition, our semi-analytical BER provides a lower bound for the Viterbi-Viterbi (VV) BER, while showing the analytical BER previously proposed in the literature shows an overly pessimistic prediction of VV BER performance. We show that inaccuracy in previous analysis stems from overly simple model for the CPE when compensating large accumulated dispersion electronically. Finally, we study extension of our results to quadrature amplitude modulation (QAM). Preliminary simulation results are promising but the accuracy of our semi-analytical approach for predicting BER should be investigated further.