Investigation into a class of nonlinear cyclic binary sequences: generation, properties and applications

In earlier papers finite pseudorandom binary sequences were studied, quantitative measures of pseudorandomness of them were introduced and studied, and large families of “good” pseudorandom sequences were constructed. In certain applications (cryptography) it is not enough to know that a family of “good” pseudorandom binary sequences is large, it is a more important property if it has a “rich”, “complex” structure. Correspondingly, the notion of “f-complexity” of a family of binary sequences is introduced. It is shown that the family of “good” pseudorandom binary sequences constructed earlier is also of high f-complexity. Finally, the cardinality of the smallest family achieving a prescibed f-complexity and multiplicity is estimated.

Binary sequences with good autocorrelation have many applications in raging systems, spread spectrum communication systems, multi-terminal system identification, code division multiple access communications systems, and stream ciphers. Magma is a large, well-supported software package designed for computations in algebra, number theory, algebraic geometry and algebraic combinatory. We design the system to compare and analysis the binary pseudorandom sequences. It is easy to analysis the existing binary sequence and new construction. And it can compare the performance of different sequences and draw the figure. We implement it on the C# and SQL database system.

We present an integrable solution for the detection of defective sensor elements using sigma-delta-(/spl Sigma//spl Delta/)-modulation and a matched filter. The sensor element is stimulated using a pseudo random binary sequence (PRBS). The sensor signal is read out and the analog output is digitized using a /spl Sigma//spl Delta/-modulator. The binary pulse density stream of the /spl Sigma//spl Delta/-modulator is the output of the sensor system and thus should ideally contain the PRBS. A matched filter has the task of detecting the pseudo random sequence in the pulse density stream and its sampled output is compared to a threshold thus making it possible to judge the functionality of the sensor element. By evaluating the magnitude of the matched filter output it is also possible to measure the sensor sensitivity. We present a discrete solution of this method, but an integrated chip using a standard 1.2 /spl mu/m CMOS process has been designed and is being fabricated.

The purpose of this study was to compare the test-retest reliability of oxygen uptake (VO2) kinetics with carbon dioxide output (VCO2) kinetics using a pseudo random binary sequence (PRBS) exercise test. A reliable test of gas exchange kinetics would have the potential of being applied as a sports fitness test. Ten healthy male subjects agreed to participate in the study and all subjects completed two identical PRBS exercise tests (test 1 and test 2), separated by a 30 min period of inactivity. Three consecutive 300 s PRBS cycles were completed in each test with 20 s exercise intensity changes between 25 and 85 W using an electrically braked cycle ergometer. Fourier analysis was computed for frequencies 3.3, 6.7 and 10 mHz. Statistical analysis by two-way ANOVA with repeated measures did not reveal significant differences between test 1 and test 2 for either VO2 kinetics or VCO2 kinetics. Static gain of VO2 for test 1 [9.11 (SD 0.59) ml.min-1.W-1] and test 2 [9.23 (SD 0.64) ml.min-1.W-1] did not differ significantly between tests. The 95% limits of agreement for VCO2 kinetics displayed increased variability in comparison to VO2 kinetics at each frequency of amplitude ratio and phase shift. Systematic bias ranged between 0% and 4%, except at frequency 10 mHz of VCO2 kinetics phase shift which showed a 10% bias for slower VO2 kinetics in test 2. It is possible that the increased variability of VCO2 kinetics compared to VO2 kinetics might be attributable to a lower signal to noise ratio in VCO2 kinetics, variations in ventilation or the storage mechanisms of CO2. The lower variability of VO2 kinetics compared with VCO2 kinetics suggests that the PRBS test of VO2 kinetics has the greater potential for further development as an indicator of aerobic fitness.

Applications like fuel cells, batteries or food analysis are typical fields of interest for electrical impedance spectroscopy (EIS).Another field with promising results are EIS measurements in semiconductor (sc) gas sensor applications [1].Due to their high sensitivity and low cost, sc gas sensors are ideally suited for different applications, especially in the field of safety and security.The major drawbacks of sc gas sensors, i.e. poor selectivity and sensor baseline drift, can be overcome by using temperature cycled operation (TCO) with DC measurement [2] or EIS, both in combination with intelligent signal processing.Currently, EIS for sc gas sensors is only possible in laboratory environments using commercial impedance analyzers, which are characterized by high cost, poor mobility and long acquisition time.However, for efficient development of application specific sc gas sensor systems and/or a self-monitoring strategy [3] extensive field tests are necessary.Therefore, a new hardware concept for EIS of sc gas sensors based on FPGA-technology was developed.This concept also allows a combination of EIS with TCO for the first time.Additionally, state-of-the-art feature extraction methods are applied to sc gas sensor data and new features were tested [4]. MotivationDue to their high sensitivity and low cost, semiconductor gas sensors are ideally suited for safety and security applications like fire and leakage detection [5,6].The major drawbacks of this type of sensor are the poor selectivity, the sensor baseline drift and sensor poisoning.Especially for safety and security applications these drawbacks must be overcome to allow a proper function of the system.Temperature cycled operation (TCO) and electrical impedance spectroscopy (EIS) -both in combination with intelligent signal processing -are the main approaches for improving both selectivity and stability.In TCO mode the sensor temperature is changed periodically [2] and the DC resistance of the sensor is read-out continually during this cycle.For EIS the sensor temperature is usually kept constant and the sensor impedance is measured over a wide frequency range, e.g. during a frequency sweep [1,7,8].To detect a sensor malfunction due to sensor poisoning a self-monitoring strategy can be realized by combining TCO und EIS (fig. 1) [3].This strategy is based on redundant information from both modes which are evaluated separately and comparing both results.Additional information can be used for selectivity enhancement.

Objective: Design of quadriphase codes with superior merit factor in basically a nonlinear multivariable optimization problem. Quadriphase transformation is applied to low side lobes in bi phase generation of binary sequence. In order to provide real time hardware for identification and generation of quadriphase pulse compression sequences. Methods/ Statistical Analysis: An efficient VLSI architecture has been proposed. The objectives to achieve high main lobe and low side lobes by poly phase codes. Findings: Initially pulse compression techniques are applied followed by binary quadriphase transformation. By applying a transformation to the biphase code using of sub pulses consequently results in the generation of codes. Near constant envelopes are created. Improvements/Applications: The systematic quadriphase sequences are useful for application to radar and continuation. There is scope for further development of merit factor. Keywords: Merit Factor (MF), Pseudo Random Binary Sequence (PRBS) Generator, Pulse Compression, Quadriphase Sequence

This paper presents a method for converting the full waveform electromagnetic response excited by the pseudo-random binary sequences (PRBS) into subsurface resistivity cross section, based on the recovery of the transient electromagnetic diffusion field. The impulse response of the earth is extracted from the full waveform data efficiently using the Wiener-Hopf equation. Then, the backward accumulation is used to obtain the step off response from the extracted earth impulse response. An OCCAM inversion routine, which incorporates the band limitation of the derived transient, is adopted to produce the geoelectric models. Finally, the method was applied to the experimental field data set, and the consistency between the recovered models and the geological condition verifies the validity of this method.

The investigation of patients who are unable to fixate the pattern visual stimulus generally requires the use of diffuse flash stimulation to elicit the visual evoked response. However, by comparison with pattern, flash stimulation has proved relatively insensitive in identifying lesions of the visual pathway. We investigated a more complex method of flash stimulation. A pseudorandom binary sequence has been used to generate the diffuse visual evoked response stimulus. The pseudorandom binary sequence, rather than producing a single flash, switches in a pseudorandom fashion between two levels of illumination. The result is a diffuse visual stimulus approximating band-limited white noise. The series is periodic, enabling signal averaging to be performed. By applying the methods of random signal analysis, the impulse or transient response of the visual pathway can be determined. Our normal pseudo-random binary sequence visual evoked response impulse function, derived from 29 normal subjects, had the morphologic characteristics of the conventional flash visual evoked response and a major positive component (P100), whose latency mean and standard deviation closely matched that of our normative pattern visual evoked response. However, the P100 amplitude standard deviation was significantly greater than that produced by conventional pattern and flash stimulation. We investigated 140 patients by means of pattern, flash and pseudorandom binary sequence stimulation. The pseudorandom binary sequence visual evoked response proved to be almost 12 times more effective than flash visual evoked response in detecting lesions of the visual system.

On the correlation of binary sequences

With the increasing reliance on technology, it has become crucial to secure every aspect of online information where pseudo random binary sequences (PRBS) can play an important role in today’s world of Internet. PRBS work in the fundamental mathematics behind the security of different protocols and cryptographic applications. This paper proposes a new PRBS namely MK (Mamun, Kumu) sequence for security applications. Proposed sequence is generated by primitive polynomial, cyclic difference set in elements of the field and binarized by quadratic residue (QR) and quadratic nonresidue (QNR). Introduction of cyclic difference set makes a special contribution to randomness of proposed sequence while QR/QNR-based binarization ensures uniformity of zeros and ones in sequence. Besides, proposed sequence has maximum cycle length and high linear complexity which are required properties for sequences to be used in security applications. Several experiments are conducted to verify randomness and results are presented in support of robustness of the proposed MK sequence. The randomness of proposed sequence is evaluated by popular statistical test suite, i.e., NIST STS 800-22 package. The test results confirmed that the proposed sequence is not affected by approximations of any kind and successfully passed all statistical tests defined in NIST STS 800-22 suite. Finally, the efficiency of proposed MK sequence is verified by comparing with some popular sequences in terms of uniformity in bit pattern distribution and linear complexity for sequences of different length. The experimental results validate that the proposed sequence has superior cryptographic properties than existing ones.

The existing random carrier pulse‐width modulation (RCPWM) schemes result in poor non‐deterministic characteristics. They basically use a single‐frequency triangular carrier and its inverted version to synthesise the random carrier by a pseudo‐random binary sequence (PRBS) bit selector. Even though the bits are highly random in nature with large pattern repetition rate, the resulting random carrier does not possess required level of randomness. Rather it can make slight positional variation in the resulting PWM pulses. Moreover, the harmonic spreading effects of these randomness may not be sufficient to meet the expectations of modern drives. Hence, this study proposes a multiple carriers based RCPWM (MCBRCPWM) scheme for the voltage‐source inverter fed induction motor drive to enhance the harmonic power spreading ability of the modulator. The proposed MCBRCPWM scheme utilises the non‐deterministic characteristics of both the PRBS and hopping action between the MCs involved. The simulation results using MATLAB 7.1.0 (2010a)‐Simulink software and the experimental results with hardware implemented using XC6SLX45 field programmable gate array for a 3Ø squirrel cage induction motor load prove the excellent harmonic spectra spreading capability of the proposed scheme as compared with existing non‐deterministic methods.

We present a construction for binary pseudorandom sequences of period 2/sup m/-1 with ideal autocorrelation property using the polynomial z/sup d/+(z+1)/sup d/. We show that the sequence obtained from the polynomial becomes an m-sequence for certain values of d. We also find a few values of d which yield new binary sequences with ideal autocorrelation property when m is 3k/spl plusmn/1, where k is a positive integer. These new sequences are represented using a trace function and the results are tabulated.

Randomized modulation technology can effectively suppress high frequency noise in motor drive application. This paper is devoted to issues in synthesis of randomized modulation schemes and proposes a dual random PWM technology based on two-state Markov chain and pseudo-random binary sequence (PRBS). This combined type of randomized modulation can make the switching cycle more evenly distributed and significantly suppress the high frequency noise focused on the switching frequency and its integer multiples. We focus on the power spectra of certain associated waveforms. Furthermore, the DTP-PMSM model with random PWM has been built to evaluate the effect with random PWM modulations based on four methods including conventional method, Markov chains, PRBS and the method combining Markov chain with PRBS. The simulation results prove that proposed PWM strategy possesses excellent harmonic power spreading ability and high frequency noise suppression capability.

On the basis of nonlinear systems with dynamic chaos, discrete chaotic signals with high information capacity have been developed and studied. The influence of the main parameters of a generating chaotic algorithm with delay on the statistical, correlation, structural and fractal characteristics of non-periodic pseudo-random integer and binary sequences generated by the algorithm is analyzed by numerical methods. It is shown that non-periodic pseudo-random sequences (PRS) generated by a chaotic algorithm with delay, for all values of the main parameters, have good statistical, correlation, structural and fractal characteristics, close to random sequences of independent trials. It is shown that these characteristics are provided on a long PRS cycle in a multidimensional phase space for all the main parameters of the chaotic algorithm and an arbitrary choice of initial conditions. Such binary PRSs can be quite effectively used in telecommunication systems using streaming coding of large blocks of information messages from the point of view of secrecy, noise immunity and cryptographic stability of the communication channel.

Battery energy storage is becoming a vital part of green energy systems. Prediction of the state of health of energy storage systems is difficult as it relies on a number of parameters. Pseudo Random Binary Sequence (PRBS) excitation of energy storage batteries has been shown to be a valid method of battery parameter identification for lead acid batteries [1]. The purpose of this work is to validate PRBS test data from a 3Ah LiFePO4 cell forming part of an EV battery-pack cell against Electrochemical Impedance Spectroscopy (EIS) data obtained from an industry-standard potentiostat (Solartron 1480). PRBS results are obtained in under 200 seconds on easily reproducible equipment which can be built into a green energy battery management system, while the EIS process takes over two hours on prohibitively expensive laboratory equipment. This work validates PRBS as a fast and portable method of obtaining the impedance spectrum of Lithium Ion cells, which can then be used to obtain information about SoH of the BESS.