## Method for Reducing the “Noise Floor” of Digital Phase Fluctuation Analyzers

Transactions of IAA RAS, issue 52, 31–35 (2020)

**DOI**: 10.32876/ApplAstron.52.31-35

**Keywords**:
digital signal processing, spectral power density of phase fluctuations, frequency standart, maximum likelihood method

### Abstract

The purpose of the paper is to further develop the previously proposed method of digital signal processing of precision frequency and time standards for measuring phase noise. The solution to a number of problems of creating high-current setting quantum generators is impossible without the use of automated information and measurement systems for precision measurement of the spectral power density of phase fluctuations of signals, since phase noise is probably the most important criterion for frequency stability of generators and synthesizers. The current state of microelectronics allows us to implement optimal methods of measuring the phase shift of radio signals (in particular, orthogonal ones) in digital form when constructing such systems. A special feature of this algorithm is the use of a quantum pulse frequency synthesizer that is synchronized with a reference signal. The method proposed for evaluating metrological parameters of phase and frequency is particularly useful when analyzing the spectrum of phase fluctuations near the carrier frequency of the signal, where high resolution is required. In addition, the method is based on a two-channel phase estimation algorithm, which, in contrast to the known algorithms, significantly reduces the parasitic influence of the phase error of the reference signal. The relatively low computational complexity of the method is achieved by a special selection of the frequency of the quantizing signal. The paper substantiates the main idea of the method proposed and provides a detailed mathematical description of the measurement process. It is shown that the high sensitivity of the method is achieved due to the stroboscopic effect during time quantization of the signal studied. The implementation of the synthesized algorithm is shown by the example of the digital structure of a high-precision estimation of the phase difference based on the orthogonal method. This algorithm is the basis for the development of a precision digital device for evaluating the characteristics of phase and frequency stability.

### Citation

`V. A. Karelin, A. S. Smelchakov. Method for Reducing the “Noise Floor” of Digital Phase Fluctuation Analyzers // Transactions of IAA RAS. — 2020. — Issue 52. — P. 31–35.`

```
@article{karelin2020,
abstract = {The purpose of the paper is to further develop the previously proposed method of digital signal processing of precision frequency and time standards for measuring phase noise. The solution to a number of problems of creating high-current setting quantum generators is impossible without the use of automated information and measurement systems for precision measurement of the spectral power density of phase fluctuations of signals, since phase noise is probably the most important criterion for frequency stability of generators and synthesizers. The current state of microelectronics allows us to implement optimal methods of measuring the phase shift of radio signals (in particular, orthogonal ones) in digital form when constructing such systems. A special feature of this algorithm is the use of a quantum pulse frequency synthesizer that is synchronized with a reference signal.
The method proposed for evaluating metrological parameters of phase and frequency is particularly useful when analyzing the spectrum of phase fluctuations near the carrier frequency of the signal, where high resolution is required. In addition, the method is based on a two-channel phase estimation algorithm, which, in contrast to the known algorithms, significantly reduces the parasitic influence of the phase error of the reference signal. The relatively low computational complexity of the method is achieved by a special selection of the frequency of the quantizing signal. The paper substantiates the main idea of the method proposed and provides a detailed mathematical description of the measurement process. It is shown that the high sensitivity of the method is achieved due to the stroboscopic effect during time quantization of the signal studied. The implementation of the synthesized algorithm is shown by the example of the digital structure of a high-precision estimation of the phase difference based on the orthogonal method. This algorithm is the basis for the development of a precision digital device for evaluating the characteristics of phase and frequency stability.},
author = {V.~A. Karelin and A.~S. Smelchakov},
doi = {10.32876/ApplAstron.52.31-35},
issue = {52},
journal = {Transactions of IAA RAS},
keyword = {digital signal processing, spectral power density of phase fluctuations, frequency standart, maximum likelihood method},
pages = {31--35},
title = {Method for Reducing the “Noise Floor” of Digital Phase Fluctuation Analyzers},
url = {http://iaaras.ru/en/library/paper/2032/},
year = {2020}
}
```

```
TY - JOUR
TI - Method for Reducing the “Noise Floor” of Digital Phase Fluctuation Analyzers
AU - Karelin, V. A.
AU - Smelchakov, A. S.
PY - 2020
T2 - Transactions of IAA RAS
IS - 52
SP - 31
AB - The purpose of the paper is to further develop the previously
proposed method of digital signal processing of precision frequency
and time standards for measuring phase noise. The solution to a
number of problems of creating high-current setting quantum
generators is impossible without the use of automated information
and measurement systems for precision measurement of the spectral
power density of phase fluctuations of signals, since phase noise is
probably the most important criterion for frequency stability of
generators and synthesizers. The current state of microelectronics
allows us to implement optimal methods of measuring the phase shift
of radio signals (in particular, orthogonal ones) in digital form
when constructing such systems. A special feature of this algorithm
is the use of a quantum pulse frequency synthesizer that is
synchronized with a reference signal. The method proposed for
evaluating metrological parameters of phase and frequency is
particularly useful when analyzing the spectrum of phase fluctuations
near the carrier frequency of the signal, where high resolution is
required. In addition, the method is based on a two-channel phase
estimation algorithm, which, in contrast to the known algorithms,
significantly reduces the parasitic influence of the phase error of
the reference signal. The relatively low computational complexity of
the method is achieved by a special selection of the frequency of the
quantizing signal. The paper substantiates the main idea of the
method proposed and provides a detailed mathematical description of
the measurement process. It is shown that the high sensitivity of the
method is achieved due to the stroboscopic effect during time
quantization of the signal studied. The implementation of the
synthesized algorithm is shown by the example of the digital
structure of a high-precision estimation of the phase difference
based on the orthogonal method. This algorithm is the basis for the
development of a precision digital device for evaluating the
characteristics of phase and frequency stability.
DO - 10.32876/ApplAstron.52.31-35
UR - http://iaaras.ru/en/library/paper/2032/
ER -
```