CN110739965B

CN110739965B - Nonlinear amplification method and nonlinear amplification device for phase noise

Info

Publication number: CN110739965B
Application number: CN201910893880.2A
Authority: CN
Inventors: 张建国; 杜海鋆; 王云才; 李璞; 王安帮; 刘峰
Original assignee: Taiyuan University of Technology
Current assignee: Taiyuan University of Technology
Priority date: 2019-09-20
Filing date: 2019-09-20
Publication date: 2023-05-16
Anticipated expiration: 2039-09-20
Also published as: CN110739965A

Abstract

The invention belongs to the technical field of integrated circuits, and particularly relates to a nonlinear amplification method and device for phase noise; the device comprises a ring oscillator, wherein the ring oscillator consists of M logic devices, the logic devices of 0 node execute exclusive OR operation, and the logic devices of other nodes execute exclusive OR operation; two input ends of each node logic device are respectively connected with output ends of two adjacent node logic devices; the logic devices of each node are provided with two inputs by two adjacent logic gates, the output after logic operation is fed back to the inputs of the logic devices of the two adjacent nodes, and the logic devices of all nodes in the ring oscillator can output signals; the invention can carry out nonlinear amplification on the phase noise in the periodic oscillation to generate a broadband phase noise signal by only a small number of digital logic gates, is easy to realize integration, miniaturization and low power consumption, and solves the problem of smaller phase jitter in the traditional ring oscillator.

Description

Nonlinear amplification method and nonlinear amplification device for phase noise

Technical Field

The invention belongs to the technical field of integrated circuits, and particularly relates to a nonlinear amplification method and device for phase noise.

Background

Phase noise refers to fluctuations in the instantaneous frequency or phase of an output signal caused by various random noises in a signal source, and is generally caused by various random noises (such as thermal noises generated by resistors, pop noises and flicker noises generated by semiconductor devices, etc.) generated by devices in an oscillator itself.

The phase noise is an important index for measuring the frequency stability quality of a frequency standard source (high stable crystal oscillator, atomic frequency standard and the like), has great influence on the performance of electronic equipment and electronic systems, and can reduce the signal-to-noise ratio of a speech channel and increase the bit error rate if the signal-to-noise ratio of the speech channel is reduced in a communication system; in radar systems, the resolving power of the target is affected, etc. With the development of electronic technology, the requirements on phase noise of frequency sources are more and more strict, and the requirements are paid attention to various fields of physics, astronomy, radio communication, radar, aviation, aerospace, precision metering, instruments, meters and the like.

However, in the fields of information security, cryptography, etc., phase noise is an important source of physical randomness. The physical random number generated by the phase noise has unpredictability and can meet the application field with higher safety. In 1999, intel corporation developed true random number generators based on this approach (Petrie C S, connelly J a Modeling and simulation of oscillator-based random number generators C// IEEE International Symposium on Circuits & systems IEEE, 1996.) in current random number generator schemes based on phase noise, the jitter of the phase noise caused by the oscillator is only tens of ps, while lower jitter means lower random bit sequence distribution characteristics, randomness and real-time rate. To achieve high throughput and sufficient randomness cannot be achieved by relying solely on the frequency drift of the oscillator, requiring the addition of post-processing or other noise sources.

Disclosure of Invention

The invention overcomes the defects existing in the prior art and provides a phase noise nonlinear amplification method and device. The method solves the problem of small phase noise jitter in the random number generator based on phase noise, and the phase noise of tens of ps is amplified into broadband phase noise of a plurality of ns through chaos nonlinearity.

The invention is realized by the following technical scheme.

The phase noise nonlinear amplifying device comprises a ring oscillator and a signal output line, wherein the ring oscillator consists of M logic devices, M=1, 2 and 3 … … n, wherein the logic devices of 0 node execute exclusive-or non-operation, and the other nodes execute exclusive-or operation; the two input ends of each node are respectively connected with the output ends of two adjacent nodes through signal output lines.

Preferably, the ring oscillator is composed of 18 logic devices, wherein the logic devices of 0 nodes perform exclusive-or operation, and the logic devices of the other 17 nodes perform exclusive-or operation.

Preferably, the ring oscillator outputs signals in two different states by adjusting the working voltage output period and chaos.

Preferably, all nodes of the ring oscillator serve as output signals.

A nonlinear amplification method for phase noise is to power up the ring oscillator, an exclusive OR NOT gate of 0 node plays a role in triggering the ring oscillator, and a signal jumps from low level to high level through the 0 node to enable the ring oscillator to oscillate; the two inputs of each node are provided by the outputs of two adjacent logic gates; the output after logic operation is fed back to the input of the logic devices of the adjacent two nodes; the phase noise is regulated by regulating the voltage control output period and chaotic signals in two different states.

Preferably, the ring oscillator outputs a boolean chaotic signal when operating at high voltage.

Preferably, the logic device filters out high frequency components and outputs the high frequency components as a periodic oscillation signal when the logic device operates at a low voltage.

A ring oscillator is composed of a plurality of logic gates, and all nodes are connected end to form a closed network. Unlike conventional ring oscillators, the ring oscillator consists of a two-input xor or xor not gate, where node 0 is the xor not gate and the other nodes are xor gates.

The two logic inputs of each node are respectively provided by the outputs of the two adjacent nodes, and the outputs after logic operation are respectively fed back to the inputs of the two adjacent nodes. The ring oscillator can start vibrating without a clock signal after being powered up. The xor not logic gate of the 0 node plays a role in triggering in the ring oscillator, and the signal jumps from low level to high level through the 0 node, so that the oscillator can oscillate.

The ring oscillator can normally work in a wide voltage range, and when the working voltage is low, a high-frequency component is filtered by a low-pass filtering effect in the digital logic device and is output as a periodic oscillation signal, and the phase jitter of the periodic signal is only tens of ps. When the working voltage is higher, the ring oscillator can output a Boolean chaotic signal, and the biggest characteristic of chaotic motion is the sensitivity dependence on an initial value, namely, if the initial value in the chaotic system has a small change, the motion track is greatly changed. The phase noise in the periodic signal is amplified by the nonlinear of the chaotic system, and a broadband phase noise signal is output. The magnitude of the phase jitter increases to tens of ns, with higher jitter meaning that a random number sequence with higher real-time rate can be extracted from it.

Compared with the prior art, the invention has the following beneficial effects.

The invention can carry out nonlinear amplification on the phase noise in the periodic oscillation to generate a broadband phase noise signal by only a small number of digital logic gates, is easy to realize integration, miniaturization and low power consumption, and solves the problem of smaller phase jitter in the traditional ring oscillator. The method comprises the following steps:

1. the invention can solve the problem caused by smaller phase noise jitter in the current random number generator, and can destroy the random distribution of the original noise when amplifying the noise and has lower speed when extracting the random sequence.

2. The method is realized by adopting the digital logic gate, has simple circuit structure and is easy to realize integration and miniaturization.

3. The method can amplify the phase jitter of several ps in the periodic signal to tens of ns through chaos nonlinearity, and effectively improves the phase noise.

4. The phase noise after nonlinear amplification has the characteristics of wide frequency spectrum and high entropy value, and has important values in the fields of secret communication systems, random number generators, optical radars, optical fiber sensing and the like.

Drawings

Fig. 1 is a schematic diagram of a phase noise nonlinear amplifying device according to the present invention.

Fig. 2 is a phase noise nonlinear amplification device composed of 18 logic devices.

Fig. 3 is a phase jitter distribution of a periodic signal.

Fig. 4 is a phase jitter distribution of broadband phase noise.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the invention is further described in detail by combining the embodiments and the drawings. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. The technical scheme of the present invention is described in detail below with reference to examples and drawings, but the scope of protection is not limited thereto.

As shown in fig. 2, a circuit for implementing a phase noise nonlinear amplification device based on discrete logic devices is exemplified by 18 nodes, wherein 0 node is an exclusive or gate, and the other 17 nodes are exclusive or gates. The logic gate types are SN74AUC1G86 and SN74AUC1G04, and the power supply voltage is 0.7V-2.8V.

The structure principle is shown in figure 1, two signal input ends of each node are respectively connected with output ends of two adjacent nodes, and the output after logic operation is respectively fed back to the two adjacent nodes. That is, the two inputs of exclusive-or not gate 0 are connected to the outputs of exclusive-or gates 1 and 17, and the two outputs of exclusive-or gate 0 are connected to the inputs of exclusive-or gates 1 and 17, and the other nodes are connected as described above. The circuit can normally work in a voltage range of 0.8V-2.7V, and 18 nodes can be used as output ends after noise signals are amplified.

The exclusive nor logic gate plays a role in triggering in the circuit, when the circuit is powered on, the outputs of the nodes 1 and 17 are low level, at the moment, the 0 node (exclusive nor logic gate) outputs high level through logic operation, and the ring oscillator starts to oscillate.

The operating voltage of a discrete logic device affects the propagation delay of the device, with a larger operating voltage resulting in a smaller propagation delay of the logic device. The low-pass filter effect of the logic device is related to the device delay parameter, and the relationship between the low-pass filter coefficient and the device delay is as follows:

. Delay of discrete logic device when phase noise nonlinear amplifying circuit works at low voltageThe delay is larger, the low-pass filter effect of the discrete logic device has lower cut-off frequency, high-frequency components in the circuit are filtered, and the nodes in the ring oscillator output periodic signals. When the circuit works at high voltage, the cut-off frequency of the low-pass filtering effect of the discrete logic device is higher, and due to the fact that the transmission among the logic gates is delayed incompletely, when the output of the logic gates transits to an adjacent node, the transmission delay deviation is accumulated continuously, and the signal output presents chaotic change. The chaotic system is highly sensitive to an initial value, and a small change can cause a great change of a motion track, so that a broadband phase noise signal is generated by the inherent phase jitter in the ring oscillator through chaotic nonlinear amplification.

Specifically, when the operating voltage of the circuit is 1.25V, the output signal is a periodic signal. The phase noise jitter profile of the periodic signal is only a few ps at this time, as shown in fig. 3. A smaller phase noise jitter means that there is not enough randomness and a lower random number rate when applied in the random number field.

When the working voltage of the circuit is 1.8V, the output signal is a chaotic signal. At this time, the inherent period jitter of the oscillator reaches a number ns through the chaotic nonlinear amplification jitter range, and as shown in fig. 4, the larger phase noise jitter means that the random number with better speed can be extracted.

While the invention has been described in detail in connection with specific preferred embodiments thereof, it is not to be construed as limited thereto, but rather as a result of a simple deduction or substitution by a person having ordinary skill in the art to which the invention pertains without departing from the scope of the invention defined by the appended claims.

Claims

1. A phase noise nonlinear amplification method is characterized in that a phase noise nonlinear amplification device is adopted for carrying out phase noise nonlinear amplification; the phase noise nonlinear amplifying device comprises a ring oscillator and a signal output line, wherein the ring oscillator consists of M logic devices, M=1, 2 and 3 … … n, wherein the logic devices of 0 node execute exclusive-or non-operation, and the other nodes execute exclusive-or operation; the two input ends of each node are respectively connected with the output ends of two adjacent nodes through signal output lines;

the ring oscillator consists of 18 logic devices, wherein the logic devices of 0 node execute exclusive OR operation, and the logic devices of other 17 nodes execute exclusive OR operation; the ring oscillator outputs signals in two different states by adjusting the working voltage output period and chaos; all nodes of the ring oscillator are used as output signals;

powering up the ring oscillator, enabling an exclusive OR not logic gate of 0 node to play a role in triggering the ring oscillator, and jumping a signal from a low level to a high level through the 0 node to enable the ring oscillator to oscillate; the two inputs of each node are provided by the outputs of two adjacent logic gates; the output after logic operation is fed back to the input of the logic devices of the adjacent two nodes; the phase noise is regulated by regulating the voltage to control the output period and chaotic signals in two different states, and when the working voltage of the circuit is 1.8V, the output signal is a chaotic signal.

2. The method of claim 1, wherein the ring oscillator outputs a boolean chaotic signal when operating at high voltage.

3. The method of claim 1, wherein the logic device filters out high frequency components during low voltage operation and outputs the high frequency components as a periodic oscillation signal.