Digital Noise Generator Research Articles

DIGITAL OSCILLATOR CIRCUIT WITH AN EXTENDED REPETITION PERIOD OF A PSEUDO-RANDOM PULSE SEQUENCE

In this paper, we consider the issue of upgrading the circuit of a digital generator of a pseudo-random pulse sequence, which can be used to create cryptographic encryption algorithms. The need to modernize the digital generator circuit is associated with an increase in the number of pseudorandom pulse train sequences generated at its output and with pseudorandom intervals between them. To achieve this, a small number of additional elements are included in the circuit of a digital pseudorandom sequence of pulses based on a five-digit shift register with linear feedback. Based on the modernized circuit of a digital generator of a pseudorandom sequence of pulses and an active secondorder Slenlen-Key RC low-pass filter, a digital acoustic noise generator is constructed, which, unlike the prototype, has a truly random output signal over a period of ~ 4 * (2N - 1), subject to circuit simplicity.

Digital Noise Generator Design Using Inverted 1D Tent Chaotic Map

This paper shows a digital noise generator designed in FPGA, based on a variant of the one‐dimensional (1D) chaotic tent map (T‐1D). The T‐1D map is a piecewise linear 1D chaotic map that defines the statistical behavior of the generated sequences using its control parameter. In this way, the proposed noise generator is a highly competitive alternative in cryptographic systems when the statistical behavior of the sequences is closer to the uniform statistical distribution. The proposed system uses the inverted tent chaotic map (IT‐1D), which has the same statistical behavior as the T‐1D map. The fundamental algorithm used in this system was developed based on a 64‐bit double precision format according to the numerical representation of floating point numbers defined in the IEEE‐754 standard. The proposed system is analized using mechanical statistic tools and some statistical tests defined in the NIST 800‐22SP (USA) standard. The main contribution of this work is the possibility of generating binary sequence of pseudorandom appearance by a procedure implemented in an FPGA device that translates real numbers to natural numbers preserving the statistical properties of sequences of real numbers that can be generated with the tent chaotic map in its original definition domain.

The Design of Digital Noise Generator and Its Amplitude Flatness Optimization Method

该文在高速FPGA(Field Programmable Gate Array)芯片上实现了m序列和FIR(Finite Impulsive Response)滤波算法产生幅度和带宽可控的带限白噪声,提出了一种反sinc平方函数FIR数字滤波器构建方法来补偿噪声在带内的幅度下降,极大地改善了带内幅度平坦度;另外该文还分析了该种噪声产生方法的最大带宽、带内功率平坦度和带外杂散幅度位置之间的关系以及折中设计的方法。设计结果和实际测量结果进行了对比,证明了文中方法的正确性和有效性。

A Diagnosis Testbench of Analog IP Cores for Characterization of Substrate Coupling Strength

A diagnosis testbench of analog IP cores characterizes their coupling strengths against on-chip environmental disturbances, specifically with regard to substrate voltage variations. The testbench incorporates multi-tone digital noise generators and a precision waveform capture with multiple probing channels. A prototype test bench fabricated in a 90-nm CMOS technology demonstrates the diagnosis of substrate coupling up to 400MHz with dynamic range of more than 60dB. The coefficients of noise propagation as well as noise coupling on a silicon substrate are quantitatively derived for analog IP cores processed in a target technology, and further linked with noise awared EDA tooling for the successful adoption of such IP cores in SoC integration.

A NOVEL SCHEME OF IMPLEMENTING HIGH-SPEED HIGH-PROBABILITY-RESOLUTION DIGITAL AWGN GENERATORS

Digital noise generators are basic components in communication channel emulators which are used to make the test and verification of communication systems easy and fast. In this paper, a novel scheme of implementing high-speed high-probability-resolution digital AWGN generator is proposed based on a derived universal algorithm for any white f(x)-distributed noise generation. The precision and the hardware complexity of the proposed AWGN generator are discussed in detail. Implemented with FPGA, the presented AWGN generator is utilized to test a high-speed UWB communication system and performs well with excellent precision in noise probability distribution. The proposed novel scheme of implementing digital noise generators is important and helpful in building communication channel emulators to test and verify communication systems.

Simulation and measurement of supply and substrate noise in mixed-signal ICs

Digital noise in mixed-signal circuits is characterized using a scalable macromodel for substrate noise coupling. The noise coupling obtained through simulations is verified with measured data from a digital noise generator and noise sensitive analog circuits fabricated in the 0.35-/spl mu/m heavily doped CMOS process. The simulations and measurements also demonstrate the effectiveness of including grounded guard rings and separating bulk and supply pins in digital circuits to reduce substrate coupling.

Simulating wind noise in electronic organs using digital noise generators

An electronic musical instrument of the type producing pipe organ-like sounds including a circuit for simulating wind noise by causing a random perturbation from the nominal frequency of tune, which an organ flue pipe exhibits when sounding, through the use of digital noise generators which are utilized to approximate an analog white or random noise source. The digital noise generators produce digital noise signals which are used to frequency modulate the instrument tone generator to produce substantially random perturbations in tbe generator output signal frequency. The present invention may be used with musical instruments having a single tone generator system composed of either a multiplicity of oscillators with a vibrato input, or a top octave frequency generator integrated circuit and a single oscillator with a vibrato input, or a transposer system. Furthermore, the present invention finds utility with multiple generator organ systems where all of the generators may be randomly modulated by independent and unlocked noise signals.

External non-white noise: Theory and experiment

Abstract We consider a system under the influence of an external gaussian noise with a flat spectrum and finite cut-off frequency. The stationery properties of the system are studied as a function of the correlation time of the noise. Theoretical predictions based on an expansion in powers of the correlation time are corroborated by experimental measurements on an electric circuit with a digital noise generator. The two main qualitative properties experimentally observed which can not be explained in a white noise limit theory are: (i) appearance of relative extrema of the stationery distribution for high noise intensity when the correlation time is not too small; (ii) dependence on the noise characteristics of the position of the maximum of the stationary distribution for low noise intensity.

A digital noise and sine-wave generator

A circuit is described that will digitally generate three kinds of signal useful in auditory research: broad-band pseudorandom noise, low-pass-filtered Gaussian noise, and low-distortion sine waves. This digital circuit has two advantages over its analog counterparts, ease of calibration and adaptation to computer control.

A versatile pseudo-random noise generator

A detailed design is presented for a digital pseudo-random noise generator. The instrument is built with standard integrated circuits. It produces both binary noise (pseudo-random binary sequence) and white Gaussian noise of variable bandwidth. By setting front panel switches to match tabulated octal codes, one may select a vast number of independent noise programs.

Random Vehicle Vibrations as Effected by Dry Friction in Wheel Suspensions

SUMMARY The changes of vibration comfort and stability of vehicles as effected by the value of frictional force generated in laminated springs are discussed and the probability of departure of the tyres from the ground is described. A partly automated analogue computer simulation being equivalent to a great number of highway experiments was applied in the study. The computer model was excited by several stochastic roadprofile - analogue signals generated by filters from the wide-band random signal of a digital noise generator.

The Logical Design of a Digital Pseudorandom Noise Generator

A digital pseudorandom noise generator is described and analyzed. The generator output is predictable and deterministic in nature allowing precise calibration of the signal bandwidth occupancy. It is designed by use of a linear feedback shift register and exclusive-or (modulo-two) logic elements to produce maximum cycle sequences of 2N-1 where N is switch selectable. Modulo-two arithmetic and delay operators describe the generator by use of characteristic polynomials. Many independent noise sources are derived since there is a complete lack of correlation between outputs delayed a shift command apart. The auto-correlation function of the binary signal determines the time functions suitability as a random noise source. By use of this function the corresponding spectral density function is shown to approximate (sin x/x)2. By use of this function the bandwidth of the generator is shown to be directly proportional to the shift oscillator frequency. Two examples are given illustrating the use of the generator.