PRBS Research Articles

A Soft Fast Estimation Method of PN Sequence Based on Weighting Walsh Hadamard Transform (WHT)

A Soft Fast Estimation Method of PN Sequence Based on Weighting Walsh Hadamard Transform (WHT)

Research of FH-MFSK Underwater Acoustic Communication Based on Non-Binary LDPC Codes

Compared with binary-modulation, Multiple-modulation can obtain higher rate of transmission in the condition of same symbol-rate. If using binary channel codes with multiple-modulation, there exists an problem of information-loss of the probability from bit to symbol conversion. Underwater acoustic channel is an multipath, time-variation, high-noise and strong doppler-effect wireless channel, which leads to high error-rate caused by signal distortion. To solve the problems above, we adopt FH-MFSK modulation to overcome the inter-symbol interference by multipath. The PN sequence is used as a frame synchronization signal and frequency energy accumulation method is used to detect the frame-synchronization. PN hopping signal is chosen to estimate the doppler frequency-shift and using non-binary LDPC codes based on symbol for channel error codes. Finally, We perform numerical simulations and the experiments on the lake to show that compared with binary LDPC codes, non-binary LDPC codes for multiple-modulation can achieve same error-rate under lower SNR.

Research of FH-MFSK Underwater Acoustic Communication Based on Non-Binary LDPC Codes

Compared with binary-modulation, Multiple-modulation can obtain higher rate of transmission in the condition of same symbol-rate. If using binary channel codes with multiple-modulation, there exists an problem of information-loss of the probability from bit to symbol conversion. Underwater acoustic channel is an multipath, time-variation, high-noise and strong doppler-effect wireless channel, which leads to high error-rate caused by signal distortion. To solve the problems above, we adopt FH-MFSK modulation to overcome the inter-symbol interference by multipath. The PN sequence is used as a frame synchronization signal and frequency energy accumulation method is used to detect the frame-synchronization. PN hopping signal is chosen to estimate the doppler frequency-shift and using non-binary LDPC codes based on symbol for channel error codes. Finally, We perform numerical simulations and the experiments on the lake to show that compared with binary LDPC codes, non-binary LDPC codes for multiple-modulation can achieve same error-rate under lower SNR.

SYSTEM IDENTIFICATION OF A STEAM DISTILLATION PILOTSCALE USING ARX AND NARX APPROACHES

This paper presents steam temperature models for st eam distillation pilot-scale (SDPS) by comparing Ps eudo Random Binary Sequence (PRBS) versus Multi-Sine (M-Sine) perturba tion signal Both perturbation signals were applied to nonlinear steam distillation system to study the capability of these input signals in exciting nonlinearity of system dynamics. In this work, both linear and nonlinear ARX model structures have been invest igated. Five statistical approaches have been obser ved to evaluate the developed steam temperature models, namely, coefficient of de termination, R 2 ; auto-correlation function, ACF; cross-correlation function, CCF; root mean square error, RMSE; and residual histogra m. The results showed that the nonlinear ARX models are superior as compared to the linear models when M-Sine perturbation appli ed to the steam distillation system. While, PRBS pe rturbation exhibit insufficient to model nonlinear system dynamic

Characterizing Porous Ceramics by Frequency-Response Method

Nondestructively determining pore properties of ceramic materials is essential in many industrial applications. There are several limitations in the existing characterization methods, so new techniques are required to meet the increasing demands of analysis. This paper examines the possible use of an electrical frequency-response method based on broadband excitation and Fourier techniques to characterize porous ceramic materials. The applied method provides a non-destructive, online characterization technique that is fast and can be applied inexpensively. In this article, ceramic samples with three different pore characteristics were measured by the frequency-response method that used a pseudo-random binary sequence. A sample of material was placed between the plates of a capacitor, and the capacitance was measured. Material properties, such as porosity, influence the permittivity value of the material. The samples with different porosities can be distinguished by analyzing the capacitance of the capacitor.

Characteristics of the slow and fast light in the band-edge of gain spectrum of the fiber-optic parametric amplification

Compared to the large slope of the gain spectrum, in this paper, the characteristics of the slow and fast light on the band-edge of gain spectrum of the narrow-band fiber-optic parametric amplification (FOPA) are analyzed. Firstly, we derive the analytical solution of the signal delay under the condition of small-signal gain. Secondly, the characteristics of 10 Gb/s pseudo-random binary sequence pulse signal delay are investigated experimentally under the condition of low pump power (<1 W). Finally, the factors that influence the signal delay, such as pump power, dispersion, nonlinear coefficient, etc. are analyzed. The results obtained in this paper provide a detailed theoretical reference for designing slow and fast delay line in band-edge of gain spectrum of FOPA.

Frequency-Domain Identification of a Ventilated Room for Model Based Control

Efficient and accurate modeling techniques have become increasingly important in the context of model predictive control (MPC) for building automation. For modeling single-input single-output systems such as a ventilated room (with either constant air flow or constant supply temperature), system identification methods are promising and provide insight into the physical nature of these systems. In collaboration with the company SAUTER an office type test room was instrumented for experiments. Three models for the room were derived: i) an empirical transfer function estimate (ETFE) derived from a pseudo-random binary sequence input signal; ii) an ETFE derived from a relay feedback approach; iii) a physics based resistance-capacitance (RC) model.Using additional validation data, the different models and approaches were compared in terms of accuracy and efficiency. The effect of air mixing dynamics was demonstrated in an additional experiment to be one of the main differences between the experimentally identified and the RC model. An additional pole can be added to the RC model in order to compensate for the differences.

Method of Designing Generators of Pseudorandom Sequences for Information Protection Based on Shift Register with Non-Linear Feedback Function

This paper proposes an efficient, high-tech method of construction of pseudorandom binary sequences generators with a repetition period 2n for n-bit shift register with a nonlinear feedback function. The developed method is illustrated by constructing a nonlinear function feedback shift register. It is proved that the offered method requires the realization of a memory size proportional to n2 that allows making successful use of suitable generators for practical use on the shift register of the longer word.

Enhanced Mobile Authentication Techniques

Milenage algorithm applies the block cipher Rijnadael (AES) with 128 bit key and 128 bit block size. This algorithm is used in the 3GPP authentication and key generation functions (f1, f1*, f2, f3, f4, f5 and f5*) for mobile communication systems (GSM/UMTS/LTE). In this paper a modification of Milenage algorithm is proposed through a dynamic change of S-box in AES depending on secret key. To get a new secret key for every authentication process we add the random number (RAND) transmitted from the authentication center (AUC) to the contents of the fixed stored secret key (Ki) and thus the initialization of the AES will be different each new authentication process . For every change in secret key a new S-box is derived from the standard one by permuting its rows and columns with the help of a new designed PN sequence generator. A complete simulation of modified Milenage and PN sequence generator is done using Microcontroller (PIC18F452). Security analysis is applied using Avalanche test to compare between the original and modified Milenage. Tests proved that the modified algorithm is more secure than the original one due to the dynamic behavior of S-box with every change of the secret key and immunity against linear and differential cryptanalysis using Avalanche tests. This makes the modified Milenage more suitable for the applications of authentication techniques specially for mobile communication systems. Keywords—Authentication vector (AV), Modified MILENAGE Algorithm for AKA Functions (F1, F1*, F2, F3, F4, F5, F5*), AES, Dynamic S-BOX and PN Sequence Generator (LFSR).

Fast measurement of proton exchange membrane fuel cell impedance based on pseudo-random binary sequence perturbation signals and continuous wavelet transform

This paper proposes an approach to the estimation of PEM fuel cell impedance by utilizing pseudo-random binary sequence as a perturbation signal and continuous wavelet transform with Morlet mother wavelet. With the approach, the impedance characteristic in the frequency band from 0.1 Hz to 500 Hz is identified in 60 seconds, approximately five times faster compared to the conventional single-sine approach. The proposed approach was experimentally evaluated on a single PEM fuel cell of a larger fuel cell stack. The quality of the results remains at the same level compared to the single-sine approach.

Sn–Ag–Cu Solder Reflow-Capable 28-Gb/s × 4-Channel High-Density Parallel-Optical Modules

This paper describes a unique solution to the next-generation high bit-rate and high channel-density parallel-optical links whereby the size of parallel-optical modules would have to be considerably reduced. Since the main problem concerning the size of optical-to-electrical conversion part is associated with the mounting of the parallel-optical module to the printed-circuit-board (PCB), this paper puts forward a remarkably compact parallel optical-module design that can be soldered directly onto the PCB. That is made possible by the high temperature tolerance of 250 °C required for Sn-Ag-Cu solder-reflow process. The miniature parallel-optical module measures only 10.5 mm in length, 6.5 mm in width, and 1.5 mm in height. The resulting parallel-optical modules are capable of four-channel error-free parallel pseudo-random binary sequence 2 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">31</sup> -1 transmission at 28 Gb/s without using clock and data recovery as well as feed-forward error correction (FEC); hence, these parallel-optical modules are applicable in next-generation high-density 100 Gb/s Ethernet applications that use FEC.

Multifrequency radio frequency sensing with photonics-assisted spectrum compression

We propose and demonstrate a multifrequency radio frequency (RF) spectrum estimation technology. With photonic assistance, a multifrequency RF signal ranging from 0 to 1 GHz is highly spectrally compressed and sensed using a single analog-to-digital converter with analog bandwidth of 42.6 MHz. By calculating the cross correlation of pseudo random binary sequence and the encoded signal, up to 40 RF tones are precisely recognized without large computational load. The employment of optical mixing decreased the cost and increased the performance compared to its electrical counterpart. The theory and performance are also discussed.

Photonic-assisted multi-channel compressive sampling based on effective time delay pattern

In this paper, a photonic-assisted multi-channel compressive sampling scheme is proposed with one pseudo-random binary sequence (PRBS) source and Wavelength Division Multiplexing-based time delay. Meanwhile, the restricted isometry property of sensing matrix determined by the optimized time delay pattern is analyzed. In experiment, a four-channel photonic-assisted system with 5-GHz bandwidth was set up, where four-channel PRBS signals were generated by adding fiber-induced constant time delays to four-wavelength modulated PRBS signal, and a signal composed of twenty tones was recovered faithfully with four analog-to-digital converters (ADCs) with only 120-MHz-bandwidth.

On Properties of PN Sequences generated by LFSR – a Generalized Study and Simulation Modeling

This paper presents a study and developed simulation models for testing properties of pseudo-noise sequences. A generalized approach is considered while presenting the study of properties of pseudo-noise sequences. On the other hand MATLAB SIMULINK which a commonly available computing platform is used to develop the simulation models for testing the properties of pseudo-noise sequences.

On Properties of PN Sequences Generated by LFSR – a Generalized Study and Simulation Modeling

This paper presents a study and developed simulation models for testing properties of pseudo-noise sequences. A generalized approach is considered while presenting the study of properties of pseudo-noise sequences. On the other hand MATLAB SIMULINK which a commonly available computing platform is used to develop the simulation models for testing the properties of pseudo-noise sequences. Keywords: LFSR, PN Sequence, MATLAB, Autocorrelation, Run Length.

Minimum gain identifiable when pseudo‐random binary sequences are used for system identification in noisy conditions

A method to determine the minimum gain of the system is presented which can be identified by pseudorandom binary sequence (PRBS)-based approaches when noise is present in the output signal. A formula for the minimum gain is derived in terms of required noise resilience from the discrete Fourier transforms of the PRBS signals and white noise. The formula allows an engineer to discount noise-affected low-gain portions of the transfer function. The calculated minimum gain is compared graphically with noisy Bode plots and good agreement is shown with the actual noise level, demonstrating the usefulness of the result.

On linear complexity of binary lattices, II

The linear complexity is an important and frequently used measure of unpredictably and pseudorandomness of binary sequences. In Part I of this paper, we extended this notion to two dimensions: we defined and studied the linear complexity of binary and bit lattices. In this paper, first we will estimate the linear complexity of a truly random bit (M,N)-lattice. Next we will extend the notion of k-error linear complexity to bit lattices. Finally, we will present another alternative definition of linear complexity of bit lattices.

An Enhanced Weak Signal Acquisition Algorithm for Indoor Positioning Receiver

This paper focuses on the research of weak signal acquisition based on time-division CDMA-OFDM (TC-OFDM) system by using long PN sequence with low power. An enhanced weak signal acquisition algorithm is proposed to improve the ability of weak signal acquisition compared with regular algorithm which uses short PN sequence with high power. Simulation shows that the ability of resistance to white noise in weak signal acquisition is enhanced by 12dB. Further, because of the good correlation of long PN sequence, the performance of resistance to strong signal interference has also improved 6dB.

A 67-mW 10.7-Gb/s 60-GHz OOK CMOS Transceiver for Short-Range Wireless Communications

A low-power and high data-rate fully integrated 60-GHz on-off keying (OOK) transceiver for short-range wireless communication is demonstrated. The transceiver consists of a switch, transmitter, and receiver and uses OOK modulation for a compact and low-power design. With a highly efficient Tx, high-speed modulator/demodulator, and wideband characteristic, the transceiver has low-power and high data-rate capability. Implemented in 90-nm CMOS technology, the transmitter and the receiver consume 31 and 36 mW at 10.7 Gb/s and occupy an active footprint of 0.15 and 0.29 mm2, respectively. The transceiver with an on-board Yagi-Uda antenna achieves 10.7-Gb/s wireless OOK data transmission over 10 cm at a bit-error rate of less than 10-12 for 27 -1 pseudorandom binary sequence. As a result, the proposed transceiver achieves energy efficiency of 6.26 pJ/bit.

A note on certain modular constructions of pseudorandom binary sequences with composite moduli

J. Rivat and A. Sarkozy extended two large families of pseudorandom binary sequences to the case of composite moduli m, where m is the product of two different primes not far apart. In this paper we continue the study in this direction. We shall improve the estimates for the correlation measure of the sequences.