CN110739965A

CN110739965A - phase noise nonlinear amplification method and device

Info

Publication number: CN110739965A
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: 2020-01-31
Anticipated expiration: 2039-09-20
Also published as: CN110739965B

Abstract

The invention belongs to the technical field of integrated circuits, and particularly relates to a phase noise nonlinear amplification method and device, which specifically comprise a ring oscillator, wherein the ring oscillator consists of M logic devices, logic devices of 0 nodes execute exclusive OR operation, 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, two input ends of each node logic device are provided by two adjacent logics , output after logical operation is fed back to the input ends of the logic devices of the two adjacent nodes, and the logic devices of all the nodes in the ring oscillator can output signals.

Description

phase noise nonlinear amplification method and device

Technical Field

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

Background

The phase noise is fluctuation of 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 noise generated by a resistor, shot noise and flicker noise generated by a semiconductor device, 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 (such as a high-stability crystal oscillator and an atomic frequency standard), and has great influence on the performance of electronic equipment and an electronic system, such as reduction of the signal-to-noise ratio of a speech path and increase of the error rate in a communication system; in radar systems, the resolving power of the target, etc. Therefore, with the development of electronic technology, the requirements for phase noise of frequency sources become more and more strict, and attention is paid to the fields of physics, astronomy, radio communication, radar, aviation, aerospace, precision metering, instruments, meters and the like.

However, in the fields of information security and cryptography, phase noise is an important source of physical randomness. The physical random number generated by the phase noise is unpredictable and can meet the application field with higher safety. In 1999, the true random number generator developed by Intel corporation is based on this method (Petrie C S, connectily J a. Modelingand simulation of oscillator-based random number generators [ C ]// IEEE international Symposium on Circuits & systems, IEEE, 1996.) in the current phase noise-based random number generator scheme, the jitter of the phase noise caused by the oscillator is only tens of ps, and the 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 additional post-processing or other noise sources.

Disclosure of Invention

The invention overcomes the defects of the prior art, provides phase noise nonlinear amplification methods and devices, solves the problem of small phase noise jitter in a phase noise random number generator, and amplifies phase noise of tens of ps into broadband phase noise of ns through chaos nonlinearity.

The invention is realized by the following technical scheme.

phase noise nonlinear amplifying device, comprising a ring oscillator and a signal output circuit, wherein the ring oscillator is composed of M logic devices, M =1, 2, 3 … … n, wherein the logic device of the node 0 performs exclusive OR operation, the other nodes perform exclusive OR operation, and two input ends of each node are respectively connected with the output ends of two adjacent nodes through the signal output circuit.

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

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

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

A method for non-linear amplification of phase noise, wherein the ring oscillator is powered on, 0 node XOR logic plays a trigger role in the ring oscillator, through 0 node, the signal jumps from low level to high level to make the ring oscillator oscillate, two inputs of each node are provided by two adjacent logic outputs, the output after logic operation is fed back to the inputs of two adjacent node logic devices, and the phase noise is adjusted by adjusting two signals of voltage control output period and chaos different states.

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

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

Unlike a conventional ring oscillator, the ring oscillator is composed of two-input exclusive-OR or exclusive-OR , where node 0 is exclusive-OR and the other nodes are exclusive-OR .

The two logic inputs of each node are provided by the outputs of two adjacent nodes respectively, and the outputs after logic operation are fed back to the inputs of the two adjacent nodes respectively.

The ring oscillator can normally work in a wide voltage range, when the working voltage is low, a low-pass filtering effect in a digital logic device filters high-frequency components, the high-frequency components are output as periodic oscillation signals, only when the phase jitter of the periodic signals is dozens of ps., the ring oscillator can output Boolean chaotic signals when the working voltage is high, the chaotic motion is characterized by sensitive dependence on initial values, namely, if tiny changes of the initial values in the chaotic system can cause huge changes of motion orbits, phase noise in the periodic signals is nonlinearly amplified by the chaotic system, broadband phase noise signals are output, the magnitude of the phase jitter is increased to tens of ns, and the high jitter means that a random number sequence with a higher real-time rate can be extracted from the periodic signals.

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

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

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

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

3. The method can amplify the phase jitter of number ps of periodic signals to tens of ns through chaos nonlinearity, thereby effectively improving the phase noise.

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

Drawings

Fig. 1 is a schematic structural diagram of phase noise nonlinear amplification devices according to the present invention.

Fig. 2 shows a phase noise nonlinear amplification apparatus composed of 18 logic devices.

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

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

Detailed Description

In order to make the technical problems, technical solutions and advantages of the present invention more apparent, the present invention is further described in in detail with reference to the embodiments and the accompanying drawings.

As shown in FIG. 2, circuits for realizing a phase noise nonlinear amplification device based on discrete logic devices are provided, the circuit takes 18 nodes as an example, 0 node is XOR , the other 17 nodes are XOR , models of logic are SN74AUC1G86 and SN74AUC1G04, and the power supply voltage is 0.7V-2.8V.

The structure principle of the circuit 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 fed back to the two adjacent nodes respectively, namely, two input ends of an exclusive-nor logic 0 are connected with output ends of exclusive-or logics 1 and 17, two output ends of an exclusive-or logic 0 are connected with input ends of exclusive-or logics 1 and 17, and the connection modes of other nodes are as described above.

The nor logic triggers the circuit to power on, the output of nodes 1 and 17 is low, the 0 node (nor logic ) outputs high 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 larger operating voltages giving smaller propagation delays of the logic device. The low-pass filtering effect of the logic device is related to the device delay parameter, and the low-pass filtering coefficient and the device delay relationship are as follows:

when the circuit works at high voltage, the cut-off frequency of the low-pass filtering effect of the discrete logic device is higher, because the transmission among the logics has delay caused by incomplete , the transmission delay deviation is accumulated continuously when the output of the logic transits to the adjacent nodes, so that the signal output presents chaotic change, the chaotic system is highly sensitive to an initial value, tiny changes can cause huge changes of a motion orbit, and the inherent phase jitter in the ring oscillator generates a broadband phase noise signal 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 at this time is only a few ps as shown in fig. 3. The small phase noise jitter means that there is insufficient randomness and low random number rate when applied to the field of random numbers.

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 range of ns after chaos nonlinear amplification jitter, as shown in fig. 4, a larger phase noise jitter means that a random number with a better rate can be extracted.

While the invention has been described in further detail with reference to specific preferred embodiments , it should not be considered limited to such specific embodiments, but rather, it will be apparent to those skilled in the art that numerous and varied substitutions and modifications can be made without departing from the invention as defined by the appended claims.

Claims

The phase noise nonlinear amplification device is characterized by comprising a ring oscillator and a signal output line, wherein the ring oscillator is composed of M logic devices, M =1, 2 and 3 … … n, the logic device of a node 0 performs exclusive OR operation, the other nodes perform exclusive OR operation, and two input ends of each node are respectively connected with output ends of two adjacent nodes through the signal output line.
2. The kinds of phase noise nonlinear amplification devices of claim 1, wherein the ring oscillator is composed of 18 logic devices, wherein the logic device of 0 node performs exclusive nor operation, and the logic devices of the other 17 nodes perform exclusive or operation.
3. The kinds of phase noise nonlinear amplification devices of claim 1, wherein the ring oscillator outputs signals of two different states by adjusting the working voltage output period and chaos.
4. The kinds of phase noise nonlinear amplification devices of claim 1, wherein all nodes of the ring oscillator are used as output signals.
5. The method of claim 1, wherein the ring oscillator is powered up, the 0-node exclusive nor logic triggers the ring oscillator to oscillate by the 0-node signal jumping from low to high, the two inputs of each node are provided by the outputs of two adjacent logics , the logically operated outputs are fed back to the inputs of the two adjacent nodes, and the phase noise is adjusted by adjusting the voltage to control the output period and chaotic signals of two different states.
6. The method of nonlinear amplification of phase noise according to claim 5, wherein the ring oscillator outputs a Boolean chaotic signal when operating at high voltage.
7. The method of kinds of phase noise nonlinear amplification of claim 5, wherein, when operating at low voltage, the logic device filters out high frequency components and outputs a periodic oscillation signal.