Dependence Of Bit Error Rate Research Articles

Estimation of the Immunity of a Satellite Communication System Based on Wideband Signals in Relation to Impulse and Fluctuating Interferences

A model of a satellite communication system based on wideband signals with relative diphase encoding is developed in the paper. A system of four signals with binary phase shift keying is used. Spectra of the signals are spread by the direct sequence technique. The developed system operation under conditions of impulse electromagnetic interference and under the influence of fluctuation interference is simulated. The dependences of bit error rate on signal-to-interference ratio are evaluated in the cases of impulse interference with Johnson distribution and white Gaussian noise affecting the signal.

МЕТОДИКА МОДЕЛИРОВАНИЯ ТОПОЛОГИИ БЕСПРОВОДНЫХ СЕНСОРНЫХ СЕТЕЙ С УЧЕТОМ МЕЖУЗЛОВЫХ ПОМЕХ

The article presents the analysis of developing methods of wireless sensor networks (WSNs) topologies based on a graph structure. It indicates the prevalence of tolerance criteria for de-scribing the links between nodes, for example, the limiting distance of radio communication, a sufficient ratio of signal/energy (interference + noise). To consider the impact of inter-node interference on the network topology it is proposed to use the permissible values of bit error probabilities or erasing an information packet in case of distortion of at least one its elements as a criterion for stable communication. The algorithm for calculating an analytical model of internode communication channel is presented to evaluate the effect of intra-network additive and multiplicative noise on the reliability indicator of incoherent message reception in the form of a bit error rate. Expression for the coefficient of structural interaction of the received signal and the interference complex is obtained, which allows considering the dependence of bit error rate on the energy components of individual interference at the receiver input, frequency separation value of a signal and values of each disturbance, their phase shifts and the duration of the information bit. There has been considered practical application of the WSNs topology modeling technique for the internode communication channels with Rice fading of a useful signal and Rayleigh fading of an intra-network interference complex (a case study of using CC2500 modems as part of WSNs nodes). As a result of analysis, there have been determined the relations between nodes, for which the bit error rates do not exceed the allowable value established by requirements for channel capacity and the length of information packets. The presented modeling approach proves the possibility of improving the network topology due to developing the internode links by redistributing the frequency resource between the nodes or adjusting the operation modes of the modems.

Effect of Optical Filtering for Error-free Transmission in Optical Networks

This paper presents a new approach to maximize the dispersion-limited distance of vertical cavity surface emitting lasers (VCSELs) operating at 1550.127 nm with 10 Gb/s bit rate. Optical non return to zero (NRZ) signal is generated by using an optical band pass filter (OBPF) along with MachZehnder interferometer (MZI) at the output of VCSEL. A third order super-Gaussian and fourth order Butterworth filters are used as optical filters. The dependence of bit error rate (BER), the eye opening and transmission distance on variations in the optical filter and MZI parameters is investigated. The numerical results signify that with the proposed scheme one can enhance the single mode fiber (SMF) link-length to 127 km in the absence of electrical or optical dispersion compensation methods. Results are compared between the proposed method and transmitters implemented with VCSEL diode. General Terms Optical communications.

MODELING OF SATELLITE CHANNEL FOR TRANSMISSION OF ADS-B MESSAGES

The model of communication channel “aircraft – satellite – ground station” was built and used for modeling of ADS-B messages transmission with the help low-orbit satellite complex Iridium. Dependences of Bit Error Rate on type of signal modulation, losses on a line, diameter of antennas, nonlinearity of high power amplifier and satellite repeater gain and received.

МОДЕЛЮВАННЯ СУПУТНИКОВОГО АВІАЦІЙНОГО ЗВ’ЯЗКУ

Із використанням програмного комплекса MATLAB Simulink побудовано модель каналузв’язку «літак – супутник – наземна станція», яка дозволяє досліджувати залежностікоефіцієнта двійкових помилок від типу модуляції сигналу, швидкості передачі інформації,потужності сигналу, діаметра антен та нелінійності підсилювача високої потужності.Ці залежності вперше були порівняні з аналогічними залежностями, отриманими задопомогою програмного комплексу «Альбатрос-Бюджет» для геостаціонарного супутника.Ключові слова: діаметр антен, коефіцієнт двійкових помилок (BER), модель каналузв’язку «літак – супутник – наземна станція», нелінійність підсилювача високої потужності,потужність сигналу, супутниковий канал зв’язку, тип модуляції сигналу, швидкість передачіінформації, MATLAB Simulink.

Comparison of Bit Error Performance of Rotated PSKScheme in Rayleigh and Ricean Fading Channels

In this paper, we study the modulation diversity in PSK scheme obtained by rotating the signal constellation and incorporating bit interleaving. We derive here the expressions for the average bit error rate (ABER) of rotated PSK modulation over frequency non-selective slowly fading Rayleigh and Ricean channels using moment generating function (MGF) based approach. Numerical results are obtained to compare the performance of conventional and rotated modulation schemes. We investigate the dependence of bit error rate on signal-to-noise ratio, fading parameters and the angle of rotation. The results show the improved performance of rotated scheme over conventional method in both the fading models. Also significant gain is noted for the case of strong LOS component. We also find and discuss the optimum rotation angle in rotated PSK scheme. The symmetrical nature of BER with rotation angle is observed.

BER Analysis of OFDM Systems Impaired by Phase Noise in Frequency-Selective Fading Channels

In this paper, we study the effect of finite-power, phase-locked loop based phase noise on the bit-error-rate (BER) performance of orthogonal frequency division multiplexing (OFDM) systems in frequency-selective fading channels. It is well known the impact of phase noise on the performance of an OFDM system can be divided into a multiplicative term called common phase error (CPE) and an additive term called intercarrier interference (ICI). Based on the conditional Gaussian approximation technique, we first derive the BER formulas for BPSK, QPSK, 16-QAM, and 64-QAM modulated OFDM signals in frequency-selective Rayleigh fading channels. To further quantify the individual influence of the CPE and the ICI on system performance for different phase noise spectra, we derive the BER expressions for perfect CPE compensation cases. The analytical results obtained for frequency-selective Rayleigh fading channels are then generalized to frequency-selective Rician fading channels. Simulation results not only validate the accuracy of our analysis but also show the dependency of BERs on the shapes of phase noise spectra.

Optical Transmitter Using Side-Mode Injection Locking for High-Speed Photonic LANs

This paper discusses an optical transmitter in parallel transmission systems using variable wavelengths. We propose to apply side-mode injection locking using a Fabry-Pe/spl acute/rot laser to realize this transmitter. Important characteristics are the injection power required for single-mode lasing of a slave laser diode (LD) and its dependence on side mode m. This paper measures the required power as a function of m and proposes a new simple theory to explain the measured data. The linewidths of injection-locked LDs were experimentally investigated as a function of m. The relation between the linewidths of master and slave LDs were also measured. Finally, the paper describes fundamental transmission experiments at 1 Gb/s using an injection-locked LD to clarify the side-mode dependence of bit-error rate.

Holographic data storage with arbitrarily misaligned data pages

An improved postprocessing algorithm that can compensate for arbitrary misregistrations between a detector array and the coherent image of a pixelated two-dimensional data page is described. Previously [Opt. Lett. 26, 542 (2001)], an algorithm was reported in which both linear and quadratic interpixel cross-talk contributions are reallocated to the appropriate neighboring pixels. However, page misalignments close to +/-0.5 pixels could not be corrected to an acceptable bit-error rate because of propagation in the iterative procedure. An improved algorithm is reported in which an intentional magnification error is introduced optically and then corrected during postprocessing. Experimental results from a pixel-matched megapel volume holographic system are presented, showing that the dependence of bit-error rate on transverse detector alignment is entirely removed. This improved procedure can completely bypass constraints on page registration, optical distortion, and material shrinkage that currently hamper page-oriented holographic storage systems.

Performance analysis of correlation-based communication schemes utilizing chaos

Using chaotic signals in spread-spectrum communications has a few clear advantages over traditional approaches. Chaotic signals are nonperiodic, wideband, and more difficult to predict, reconstruct, and characterize than periodic carriers. These properties of chaotic signals make it more difficult to intercept and decode the information modulated upon them. However, many suggested chaos-based communication schemes do not provide processing gain, a feature highly desirable in spread-spectrum communication schemes. In this paper, we suggest two communication schemes that provide a processing gain. The performance of these and of the earlier proposed differential chaos shift keying is studied analytically and numerically for discrete time implementations. It is shown that, when performance is characterized by the dependence of bit error rate on E/sub b//N/sub 0/, the increase of the spreading sequence length beyond a certain point degrades the performance. For a given E/sub b//N/sub 0/, there is a length of the spreading sequence that minimizes the bit error rate.

Monte Carlo study of inductive heads with PRML recording channel

We present a Monte Carlo simulation of inductive recording heads with a PRML recording channel. We show the effects of various head parameters such as gap length, throat height, track width, pole thickness, pulse undershoot and flying height on signal to noise (SNR) and bit error rates. The analysis shows a strong dependency of bit error rate on flying height, track width and pulse undershoot.

Effect of front facet reflectivity on transmission characteristics of asymmetric reflectivity DFB lasers

We experimentally investigated the dependence of bit-errorrate of DFB lasers on facet reflectivity. We found that stable single-longitudinal-mode operation was obtained by lowering the front facet reflectivity below 1%. These DFB lasers showed no bit-error-rate floor and no mode-partition.